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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/mm/vmalloc.c
4 *
5 * Copyright (C) 1993 Linus Torvalds
6 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
7 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
8 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
9 * Numa awareness, Christoph Lameter, SGI, June 2005
10 */
11
12#include <linux/vmalloc.h>
13#include <linux/mm.h>
14#include <linux/module.h>
15#include <linux/highmem.h>
16#include <linux/sched/signal.h>
17#include <linux/slab.h>
18#include <linux/spinlock.h>
19#include <linux/interrupt.h>
20#include <linux/proc_fs.h>
21#include <linux/seq_file.h>
22#include <linux/set_memory.h>
23#include <linux/debugobjects.h>
24#include <linux/kallsyms.h>
25#include <linux/list.h>
26#include <linux/notifier.h>
27#include <linux/rbtree.h>
28#include <linux/radix-tree.h>
29#include <linux/rcupdate.h>
30#include <linux/pfn.h>
31#include <linux/kmemleak.h>
32#include <linux/atomic.h>
33#include <linux/compiler.h>
34#include <linux/llist.h>
35#include <linux/bitops.h>
36#include <linux/rbtree_augmented.h>
37
38#include <linux/uaccess.h>
39#include <asm/tlbflush.h>
40#include <asm/shmparam.h>
41
42#include "internal.h"
43
44struct vfree_deferred {
45 struct llist_head list;
46 struct work_struct wq;
47};
48static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
49
50static void __vunmap(const void *, int);
51
52static void free_work(struct work_struct *w)
53{
54 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
55 struct llist_node *t, *llnode;
56
57 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
58 __vunmap((void *)llnode, 1);
59}
60
61/*** Page table manipulation functions ***/
62
63static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
64{
65 pte_t *pte;
66
67 pte = pte_offset_kernel(pmd, addr);
68 do {
69 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
70 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
71 } while (pte++, addr += PAGE_SIZE, addr != end);
72}
73
74static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
75{
76 pmd_t *pmd;
77 unsigned long next;
78
79 pmd = pmd_offset(pud, addr);
80 do {
81 next = pmd_addr_end(addr, end);
82 if (pmd_clear_huge(pmd))
83 continue;
84 if (pmd_none_or_clear_bad(pmd))
85 continue;
86 vunmap_pte_range(pmd, addr, next);
87 } while (pmd++, addr = next, addr != end);
88}
89
90static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end)
91{
92 pud_t *pud;
93 unsigned long next;
94
95 pud = pud_offset(p4d, addr);
96 do {
97 next = pud_addr_end(addr, end);
98 if (pud_clear_huge(pud))
99 continue;
100 if (pud_none_or_clear_bad(pud))
101 continue;
102 vunmap_pmd_range(pud, addr, next);
103 } while (pud++, addr = next, addr != end);
104}
105
106static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end)
107{
108 p4d_t *p4d;
109 unsigned long next;
110
111 p4d = p4d_offset(pgd, addr);
112 do {
113 next = p4d_addr_end(addr, end);
114 if (p4d_clear_huge(p4d))
115 continue;
116 if (p4d_none_or_clear_bad(p4d))
117 continue;
118 vunmap_pud_range(p4d, addr, next);
119 } while (p4d++, addr = next, addr != end);
120}
121
122static void vunmap_page_range(unsigned long addr, unsigned long end)
123{
124 pgd_t *pgd;
125 unsigned long next;
126
127 BUG_ON(addr >= end);
128 pgd = pgd_offset_k(addr);
129 do {
130 next = pgd_addr_end(addr, end);
131 if (pgd_none_or_clear_bad(pgd))
132 continue;
133 vunmap_p4d_range(pgd, addr, next);
134 } while (pgd++, addr = next, addr != end);
135}
136
137static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
138 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
139{
140 pte_t *pte;
141
142 /*
143 * nr is a running index into the array which helps higher level
144 * callers keep track of where we're up to.
145 */
146
147 pte = pte_alloc_kernel(pmd, addr);
148 if (!pte)
149 return -ENOMEM;
150 do {
151 struct page *page = pages[*nr];
152
153 if (WARN_ON(!pte_none(*pte)))
154 return -EBUSY;
155 if (WARN_ON(!page))
156 return -ENOMEM;
157 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
158 (*nr)++;
159 } while (pte++, addr += PAGE_SIZE, addr != end);
160 return 0;
161}
162
163static int vmap_pmd_range(pud_t *pud, unsigned long addr,
164 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
165{
166 pmd_t *pmd;
167 unsigned long next;
168
169 pmd = pmd_alloc(&init_mm, pud, addr);
170 if (!pmd)
171 return -ENOMEM;
172 do {
173 next = pmd_addr_end(addr, end);
174 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
175 return -ENOMEM;
176 } while (pmd++, addr = next, addr != end);
177 return 0;
178}
179
180static int vmap_pud_range(p4d_t *p4d, unsigned long addr,
181 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
182{
183 pud_t *pud;
184 unsigned long next;
185
186 pud = pud_alloc(&init_mm, p4d, addr);
187 if (!pud)
188 return -ENOMEM;
189 do {
190 next = pud_addr_end(addr, end);
191 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
192 return -ENOMEM;
193 } while (pud++, addr = next, addr != end);
194 return 0;
195}
196
197static int vmap_p4d_range(pgd_t *pgd, unsigned long addr,
198 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
199{
200 p4d_t *p4d;
201 unsigned long next;
202
203 p4d = p4d_alloc(&init_mm, pgd, addr);
204 if (!p4d)
205 return -ENOMEM;
206 do {
207 next = p4d_addr_end(addr, end);
208 if (vmap_pud_range(p4d, addr, next, prot, pages, nr))
209 return -ENOMEM;
210 } while (p4d++, addr = next, addr != end);
211 return 0;
212}
213
214/*
215 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
216 * will have pfns corresponding to the "pages" array.
217 *
218 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
219 */
220static int vmap_page_range_noflush(unsigned long start, unsigned long end,
221 pgprot_t prot, struct page **pages)
222{
223 pgd_t *pgd;
224 unsigned long next;
225 unsigned long addr = start;
226 int err = 0;
227 int nr = 0;
228
229 BUG_ON(addr >= end);
230 pgd = pgd_offset_k(addr);
231 do {
232 next = pgd_addr_end(addr, end);
233 err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr);
234 if (err)
235 return err;
236 } while (pgd++, addr = next, addr != end);
237
238 return nr;
239}
240
241static int vmap_page_range(unsigned long start, unsigned long end,
242 pgprot_t prot, struct page **pages)
243{
244 int ret;
245
246 ret = vmap_page_range_noflush(start, end, prot, pages);
247 flush_cache_vmap(start, end);
248 return ret;
249}
250
251int is_vmalloc_or_module_addr(const void *x)
252{
253 /*
254 * ARM, x86-64 and sparc64 put modules in a special place,
255 * and fall back on vmalloc() if that fails. Others
256 * just put it in the vmalloc space.
257 */
258#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
259 unsigned long addr = (unsigned long)x;
260 if (addr >= MODULES_VADDR && addr < MODULES_END)
261 return 1;
262#endif
263 return is_vmalloc_addr(x);
264}
265
266/*
267 * Walk a vmap address to the struct page it maps.
268 */
269struct page *vmalloc_to_page(const void *vmalloc_addr)
270{
271 unsigned long addr = (unsigned long) vmalloc_addr;
272 struct page *page = NULL;
273 pgd_t *pgd = pgd_offset_k(addr);
274 p4d_t *p4d;
275 pud_t *pud;
276 pmd_t *pmd;
277 pte_t *ptep, pte;
278
279 /*
280 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
281 * architectures that do not vmalloc module space
282 */
283 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
284
285 if (pgd_none(*pgd))
286 return NULL;
287 p4d = p4d_offset(pgd, addr);
288 if (p4d_none(*p4d))
289 return NULL;
290 pud = pud_offset(p4d, addr);
291
292 /*
293 * Don't dereference bad PUD or PMD (below) entries. This will also
294 * identify huge mappings, which we may encounter on architectures
295 * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be
296 * identified as vmalloc addresses by is_vmalloc_addr(), but are
297 * not [unambiguously] associated with a struct page, so there is
298 * no correct value to return for them.
299 */
300 WARN_ON_ONCE(pud_bad(*pud));
301 if (pud_none(*pud) || pud_bad(*pud))
302 return NULL;
303 pmd = pmd_offset(pud, addr);
304 WARN_ON_ONCE(pmd_bad(*pmd));
305 if (pmd_none(*pmd) || pmd_bad(*pmd))
306 return NULL;
307
308 ptep = pte_offset_map(pmd, addr);
309 pte = *ptep;
310 if (pte_present(pte))
311 page = pte_page(pte);
312 pte_unmap(ptep);
313 return page;
314}
315EXPORT_SYMBOL(vmalloc_to_page);
316
317/*
318 * Map a vmalloc()-space virtual address to the physical page frame number.
319 */
320unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
321{
322 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
323}
324EXPORT_SYMBOL(vmalloc_to_pfn);
325
326
327/*** Global kva allocator ***/
328
329#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
330#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
331
332
333static DEFINE_SPINLOCK(vmap_area_lock);
334/* Export for kexec only */
335LIST_HEAD(vmap_area_list);
336static LLIST_HEAD(vmap_purge_list);
337static struct rb_root vmap_area_root = RB_ROOT;
338static bool vmap_initialized __read_mostly;
339
340/*
341 * This kmem_cache is used for vmap_area objects. Instead of
342 * allocating from slab we reuse an object from this cache to
343 * make things faster. Especially in "no edge" splitting of
344 * free block.
345 */
346static struct kmem_cache *vmap_area_cachep;
347
348/*
349 * This linked list is used in pair with free_vmap_area_root.
350 * It gives O(1) access to prev/next to perform fast coalescing.
351 */
352static LIST_HEAD(free_vmap_area_list);
353
354/*
355 * This augment red-black tree represents the free vmap space.
356 * All vmap_area objects in this tree are sorted by va->va_start
357 * address. It is used for allocation and merging when a vmap
358 * object is released.
359 *
360 * Each vmap_area node contains a maximum available free block
361 * of its sub-tree, right or left. Therefore it is possible to
362 * find a lowest match of free area.
363 */
364static struct rb_root free_vmap_area_root = RB_ROOT;
365
366/*
367 * Preload a CPU with one object for "no edge" split case. The
368 * aim is to get rid of allocations from the atomic context, thus
369 * to use more permissive allocation masks.
370 */
371static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
372
373static __always_inline unsigned long
374va_size(struct vmap_area *va)
375{
376 return (va->va_end - va->va_start);
377}
378
379static __always_inline unsigned long
380get_subtree_max_size(struct rb_node *node)
381{
382 struct vmap_area *va;
383
384 va = rb_entry_safe(node, struct vmap_area, rb_node);
385 return va ? va->subtree_max_size : 0;
386}
387
388/*
389 * Gets called when remove the node and rotate.
390 */
391static __always_inline unsigned long
392compute_subtree_max_size(struct vmap_area *va)
393{
394 return max3(va_size(va),
395 get_subtree_max_size(va->rb_node.rb_left),
396 get_subtree_max_size(va->rb_node.rb_right));
397}
398
399RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
400 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
401
402static void purge_vmap_area_lazy(void);
403static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
404static unsigned long lazy_max_pages(void);
405
406static atomic_long_t nr_vmalloc_pages;
407
408unsigned long vmalloc_nr_pages(void)
409{
410 return atomic_long_read(&nr_vmalloc_pages);
411}
412
413static struct vmap_area *__find_vmap_area(unsigned long addr)
414{
415 struct rb_node *n = vmap_area_root.rb_node;
416
417 while (n) {
418 struct vmap_area *va;
419
420 va = rb_entry(n, struct vmap_area, rb_node);
421 if (addr < va->va_start)
422 n = n->rb_left;
423 else if (addr >= va->va_end)
424 n = n->rb_right;
425 else
426 return va;
427 }
428
429 return NULL;
430}
431
432/*
433 * This function returns back addresses of parent node
434 * and its left or right link for further processing.
435 */
436static __always_inline struct rb_node **
437find_va_links(struct vmap_area *va,
438 struct rb_root *root, struct rb_node *from,
439 struct rb_node **parent)
440{
441 struct vmap_area *tmp_va;
442 struct rb_node **link;
443
444 if (root) {
445 link = &root->rb_node;
446 if (unlikely(!*link)) {
447 *parent = NULL;
448 return link;
449 }
450 } else {
451 link = &from;
452 }
453
454 /*
455 * Go to the bottom of the tree. When we hit the last point
456 * we end up with parent rb_node and correct direction, i name
457 * it link, where the new va->rb_node will be attached to.
458 */
459 do {
460 tmp_va = rb_entry(*link, struct vmap_area, rb_node);
461
462 /*
463 * During the traversal we also do some sanity check.
464 * Trigger the BUG() if there are sides(left/right)
465 * or full overlaps.
466 */
467 if (va->va_start < tmp_va->va_end &&
468 va->va_end <= tmp_va->va_start)
469 link = &(*link)->rb_left;
470 else if (va->va_end > tmp_va->va_start &&
471 va->va_start >= tmp_va->va_end)
472 link = &(*link)->rb_right;
473 else
474 BUG();
475 } while (*link);
476
477 *parent = &tmp_va->rb_node;
478 return link;
479}
480
481static __always_inline struct list_head *
482get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
483{
484 struct list_head *list;
485
486 if (unlikely(!parent))
487 /*
488 * The red-black tree where we try to find VA neighbors
489 * before merging or inserting is empty, i.e. it means
490 * there is no free vmap space. Normally it does not
491 * happen but we handle this case anyway.
492 */
493 return NULL;
494
495 list = &rb_entry(parent, struct vmap_area, rb_node)->list;
496 return (&parent->rb_right == link ? list->next : list);
497}
498
499static __always_inline void
500link_va(struct vmap_area *va, struct rb_root *root,
501 struct rb_node *parent, struct rb_node **link, struct list_head *head)
502{
503 /*
504 * VA is still not in the list, but we can
505 * identify its future previous list_head node.
506 */
507 if (likely(parent)) {
508 head = &rb_entry(parent, struct vmap_area, rb_node)->list;
509 if (&parent->rb_right != link)
510 head = head->prev;
511 }
512
513 /* Insert to the rb-tree */
514 rb_link_node(&va->rb_node, parent, link);
515 if (root == &free_vmap_area_root) {
516 /*
517 * Some explanation here. Just perform simple insertion
518 * to the tree. We do not set va->subtree_max_size to
519 * its current size before calling rb_insert_augmented().
520 * It is because of we populate the tree from the bottom
521 * to parent levels when the node _is_ in the tree.
522 *
523 * Therefore we set subtree_max_size to zero after insertion,
524 * to let __augment_tree_propagate_from() puts everything to
525 * the correct order later on.
526 */
527 rb_insert_augmented(&va->rb_node,
528 root, &free_vmap_area_rb_augment_cb);
529 va->subtree_max_size = 0;
530 } else {
531 rb_insert_color(&va->rb_node, root);
532 }
533
534 /* Address-sort this list */
535 list_add(&va->list, head);
536}
537
538static __always_inline void
539unlink_va(struct vmap_area *va, struct rb_root *root)
540{
541 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
542 return;
543
544 if (root == &free_vmap_area_root)
545 rb_erase_augmented(&va->rb_node,
546 root, &free_vmap_area_rb_augment_cb);
547 else
548 rb_erase(&va->rb_node, root);
549
550 list_del(&va->list);
551 RB_CLEAR_NODE(&va->rb_node);
552}
553
554#if DEBUG_AUGMENT_PROPAGATE_CHECK
555static void
556augment_tree_propagate_check(struct rb_node *n)
557{
558 struct vmap_area *va;
559 struct rb_node *node;
560 unsigned long size;
561 bool found = false;
562
563 if (n == NULL)
564 return;
565
566 va = rb_entry(n, struct vmap_area, rb_node);
567 size = va->subtree_max_size;
568 node = n;
569
570 while (node) {
571 va = rb_entry(node, struct vmap_area, rb_node);
572
573 if (get_subtree_max_size(node->rb_left) == size) {
574 node = node->rb_left;
575 } else {
576 if (va_size(va) == size) {
577 found = true;
578 break;
579 }
580
581 node = node->rb_right;
582 }
583 }
584
585 if (!found) {
586 va = rb_entry(n, struct vmap_area, rb_node);
587 pr_emerg("tree is corrupted: %lu, %lu\n",
588 va_size(va), va->subtree_max_size);
589 }
590
591 augment_tree_propagate_check(n->rb_left);
592 augment_tree_propagate_check(n->rb_right);
593}
594#endif
595
596/*
597 * This function populates subtree_max_size from bottom to upper
598 * levels starting from VA point. The propagation must be done
599 * when VA size is modified by changing its va_start/va_end. Or
600 * in case of newly inserting of VA to the tree.
601 *
602 * It means that __augment_tree_propagate_from() must be called:
603 * - After VA has been inserted to the tree(free path);
604 * - After VA has been shrunk(allocation path);
605 * - After VA has been increased(merging path).
606 *
607 * Please note that, it does not mean that upper parent nodes
608 * and their subtree_max_size are recalculated all the time up
609 * to the root node.
610 *
611 * 4--8
612 * /\
613 * / \
614 * / \
615 * 2--2 8--8
616 *
617 * For example if we modify the node 4, shrinking it to 2, then
618 * no any modification is required. If we shrink the node 2 to 1
619 * its subtree_max_size is updated only, and set to 1. If we shrink
620 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
621 * node becomes 4--6.
622 */
623static __always_inline void
624augment_tree_propagate_from(struct vmap_area *va)
625{
626 struct rb_node *node = &va->rb_node;
627 unsigned long new_va_sub_max_size;
628
629 while (node) {
630 va = rb_entry(node, struct vmap_area, rb_node);
631 new_va_sub_max_size = compute_subtree_max_size(va);
632
633 /*
634 * If the newly calculated maximum available size of the
635 * subtree is equal to the current one, then it means that
636 * the tree is propagated correctly. So we have to stop at
637 * this point to save cycles.
638 */
639 if (va->subtree_max_size == new_va_sub_max_size)
640 break;
641
642 va->subtree_max_size = new_va_sub_max_size;
643 node = rb_parent(&va->rb_node);
644 }
645
646#if DEBUG_AUGMENT_PROPAGATE_CHECK
647 augment_tree_propagate_check(free_vmap_area_root.rb_node);
648#endif
649}
650
651static void
652insert_vmap_area(struct vmap_area *va,
653 struct rb_root *root, struct list_head *head)
654{
655 struct rb_node **link;
656 struct rb_node *parent;
657
658 link = find_va_links(va, root, NULL, &parent);
659 link_va(va, root, parent, link, head);
660}
661
662static void
663insert_vmap_area_augment(struct vmap_area *va,
664 struct rb_node *from, struct rb_root *root,
665 struct list_head *head)
666{
667 struct rb_node **link;
668 struct rb_node *parent;
669
670 if (from)
671 link = find_va_links(va, NULL, from, &parent);
672 else
673 link = find_va_links(va, root, NULL, &parent);
674
675 link_va(va, root, parent, link, head);
676 augment_tree_propagate_from(va);
677}
678
679/*
680 * Merge de-allocated chunk of VA memory with previous
681 * and next free blocks. If coalesce is not done a new
682 * free area is inserted. If VA has been merged, it is
683 * freed.
684 */
685static __always_inline void
686merge_or_add_vmap_area(struct vmap_area *va,
687 struct rb_root *root, struct list_head *head)
688{
689 struct vmap_area *sibling;
690 struct list_head *next;
691 struct rb_node **link;
692 struct rb_node *parent;
693 bool merged = false;
694
695 /*
696 * Find a place in the tree where VA potentially will be
697 * inserted, unless it is merged with its sibling/siblings.
698 */
699 link = find_va_links(va, root, NULL, &parent);
700
701 /*
702 * Get next node of VA to check if merging can be done.
703 */
704 next = get_va_next_sibling(parent, link);
705 if (unlikely(next == NULL))
706 goto insert;
707
708 /*
709 * start end
710 * | |
711 * |<------VA------>|<-----Next----->|
712 * | |
713 * start end
714 */
715 if (next != head) {
716 sibling = list_entry(next, struct vmap_area, list);
717 if (sibling->va_start == va->va_end) {
718 sibling->va_start = va->va_start;
719
720 /* Check and update the tree if needed. */
721 augment_tree_propagate_from(sibling);
722
723 /* Free vmap_area object. */
724 kmem_cache_free(vmap_area_cachep, va);
725
726 /* Point to the new merged area. */
727 va = sibling;
728 merged = true;
729 }
730 }
731
732 /*
733 * start end
734 * | |
735 * |<-----Prev----->|<------VA------>|
736 * | |
737 * start end
738 */
739 if (next->prev != head) {
740 sibling = list_entry(next->prev, struct vmap_area, list);
741 if (sibling->va_end == va->va_start) {
742 sibling->va_end = va->va_end;
743
744 /* Check and update the tree if needed. */
745 augment_tree_propagate_from(sibling);
746
747 if (merged)
748 unlink_va(va, root);
749
750 /* Free vmap_area object. */
751 kmem_cache_free(vmap_area_cachep, va);
752 return;
753 }
754 }
755
756insert:
757 if (!merged) {
758 link_va(va, root, parent, link, head);
759 augment_tree_propagate_from(va);
760 }
761}
762
763static __always_inline bool
764is_within_this_va(struct vmap_area *va, unsigned long size,
765 unsigned long align, unsigned long vstart)
766{
767 unsigned long nva_start_addr;
768
769 if (va->va_start > vstart)
770 nva_start_addr = ALIGN(va->va_start, align);
771 else
772 nva_start_addr = ALIGN(vstart, align);
773
774 /* Can be overflowed due to big size or alignment. */
775 if (nva_start_addr + size < nva_start_addr ||
776 nva_start_addr < vstart)
777 return false;
778
779 return (nva_start_addr + size <= va->va_end);
780}
781
782/*
783 * Find the first free block(lowest start address) in the tree,
784 * that will accomplish the request corresponding to passing
785 * parameters.
786 */
787static __always_inline struct vmap_area *
788find_vmap_lowest_match(unsigned long size,
789 unsigned long align, unsigned long vstart)
790{
791 struct vmap_area *va;
792 struct rb_node *node;
793 unsigned long length;
794
795 /* Start from the root. */
796 node = free_vmap_area_root.rb_node;
797
798 /* Adjust the search size for alignment overhead. */
799 length = size + align - 1;
800
801 while (node) {
802 va = rb_entry(node, struct vmap_area, rb_node);
803
804 if (get_subtree_max_size(node->rb_left) >= length &&
805 vstart < va->va_start) {
806 node = node->rb_left;
807 } else {
808 if (is_within_this_va(va, size, align, vstart))
809 return va;
810
811 /*
812 * Does not make sense to go deeper towards the right
813 * sub-tree if it does not have a free block that is
814 * equal or bigger to the requested search length.
815 */
816 if (get_subtree_max_size(node->rb_right) >= length) {
817 node = node->rb_right;
818 continue;
819 }
820
821 /*
822 * OK. We roll back and find the first right sub-tree,
823 * that will satisfy the search criteria. It can happen
824 * only once due to "vstart" restriction.
825 */
826 while ((node = rb_parent(node))) {
827 va = rb_entry(node, struct vmap_area, rb_node);
828 if (is_within_this_va(va, size, align, vstart))
829 return va;
830
831 if (get_subtree_max_size(node->rb_right) >= length &&
832 vstart <= va->va_start) {
833 node = node->rb_right;
834 break;
835 }
836 }
837 }
838 }
839
840 return NULL;
841}
842
843#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
844#include <linux/random.h>
845
846static struct vmap_area *
847find_vmap_lowest_linear_match(unsigned long size,
848 unsigned long align, unsigned long vstart)
849{
850 struct vmap_area *va;
851
852 list_for_each_entry(va, &free_vmap_area_list, list) {
853 if (!is_within_this_va(va, size, align, vstart))
854 continue;
855
856 return va;
857 }
858
859 return NULL;
860}
861
862static void
863find_vmap_lowest_match_check(unsigned long size)
864{
865 struct vmap_area *va_1, *va_2;
866 unsigned long vstart;
867 unsigned int rnd;
868
869 get_random_bytes(&rnd, sizeof(rnd));
870 vstart = VMALLOC_START + rnd;
871
872 va_1 = find_vmap_lowest_match(size, 1, vstart);
873 va_2 = find_vmap_lowest_linear_match(size, 1, vstart);
874
875 if (va_1 != va_2)
876 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
877 va_1, va_2, vstart);
878}
879#endif
880
881enum fit_type {
882 NOTHING_FIT = 0,
883 FL_FIT_TYPE = 1, /* full fit */
884 LE_FIT_TYPE = 2, /* left edge fit */
885 RE_FIT_TYPE = 3, /* right edge fit */
886 NE_FIT_TYPE = 4 /* no edge fit */
887};
888
889static __always_inline enum fit_type
890classify_va_fit_type(struct vmap_area *va,
891 unsigned long nva_start_addr, unsigned long size)
892{
893 enum fit_type type;
894
895 /* Check if it is within VA. */
896 if (nva_start_addr < va->va_start ||
897 nva_start_addr + size > va->va_end)
898 return NOTHING_FIT;
899
900 /* Now classify. */
901 if (va->va_start == nva_start_addr) {
902 if (va->va_end == nva_start_addr + size)
903 type = FL_FIT_TYPE;
904 else
905 type = LE_FIT_TYPE;
906 } else if (va->va_end == nva_start_addr + size) {
907 type = RE_FIT_TYPE;
908 } else {
909 type = NE_FIT_TYPE;
910 }
911
912 return type;
913}
914
915static __always_inline int
916adjust_va_to_fit_type(struct vmap_area *va,
917 unsigned long nva_start_addr, unsigned long size,
918 enum fit_type type)
919{
920 struct vmap_area *lva = NULL;
921
922 if (type == FL_FIT_TYPE) {
923 /*
924 * No need to split VA, it fully fits.
925 *
926 * | |
927 * V NVA V
928 * |---------------|
929 */
930 unlink_va(va, &free_vmap_area_root);
931 kmem_cache_free(vmap_area_cachep, va);
932 } else if (type == LE_FIT_TYPE) {
933 /*
934 * Split left edge of fit VA.
935 *
936 * | |
937 * V NVA V R
938 * |-------|-------|
939 */
940 va->va_start += size;
941 } else if (type == RE_FIT_TYPE) {
942 /*
943 * Split right edge of fit VA.
944 *
945 * | |
946 * L V NVA V
947 * |-------|-------|
948 */
949 va->va_end = nva_start_addr;
950 } else if (type == NE_FIT_TYPE) {
951 /*
952 * Split no edge of fit VA.
953 *
954 * | |
955 * L V NVA V R
956 * |---|-------|---|
957 */
958 lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
959 if (unlikely(!lva)) {
960 /*
961 * For percpu allocator we do not do any pre-allocation
962 * and leave it as it is. The reason is it most likely
963 * never ends up with NE_FIT_TYPE splitting. In case of
964 * percpu allocations offsets and sizes are aligned to
965 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
966 * are its main fitting cases.
967 *
968 * There are a few exceptions though, as an example it is
969 * a first allocation (early boot up) when we have "one"
970 * big free space that has to be split.
971 */
972 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
973 if (!lva)
974 return -1;
975 }
976
977 /*
978 * Build the remainder.
979 */
980 lva->va_start = va->va_start;
981 lva->va_end = nva_start_addr;
982
983 /*
984 * Shrink this VA to remaining size.
985 */
986 va->va_start = nva_start_addr + size;
987 } else {
988 return -1;
989 }
990
991 if (type != FL_FIT_TYPE) {
992 augment_tree_propagate_from(va);
993
994 if (lva) /* type == NE_FIT_TYPE */
995 insert_vmap_area_augment(lva, &va->rb_node,
996 &free_vmap_area_root, &free_vmap_area_list);
997 }
998
999 return 0;
1000}
1001
1002/*
1003 * Returns a start address of the newly allocated area, if success.
1004 * Otherwise a vend is returned that indicates failure.
1005 */
1006static __always_inline unsigned long
1007__alloc_vmap_area(unsigned long size, unsigned long align,
1008 unsigned long vstart, unsigned long vend)
1009{
1010 unsigned long nva_start_addr;
1011 struct vmap_area *va;
1012 enum fit_type type;
1013 int ret;
1014
1015 va = find_vmap_lowest_match(size, align, vstart);
1016 if (unlikely(!va))
1017 return vend;
1018
1019 if (va->va_start > vstart)
1020 nva_start_addr = ALIGN(va->va_start, align);
1021 else
1022 nva_start_addr = ALIGN(vstart, align);
1023
1024 /* Check the "vend" restriction. */
1025 if (nva_start_addr + size > vend)
1026 return vend;
1027
1028 /* Classify what we have found. */
1029 type = classify_va_fit_type(va, nva_start_addr, size);
1030 if (WARN_ON_ONCE(type == NOTHING_FIT))
1031 return vend;
1032
1033 /* Update the free vmap_area. */
1034 ret = adjust_va_to_fit_type(va, nva_start_addr, size, type);
1035 if (ret)
1036 return vend;
1037
1038#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1039 find_vmap_lowest_match_check(size);
1040#endif
1041
1042 return nva_start_addr;
1043}
1044
1045/*
1046 * Allocate a region of KVA of the specified size and alignment, within the
1047 * vstart and vend.
1048 */
1049static struct vmap_area *alloc_vmap_area(unsigned long size,
1050 unsigned long align,
1051 unsigned long vstart, unsigned long vend,
1052 int node, gfp_t gfp_mask)
1053{
1054 struct vmap_area *va, *pva;
1055 unsigned long addr;
1056 int purged = 0;
1057
1058 BUG_ON(!size);
1059 BUG_ON(offset_in_page(size));
1060 BUG_ON(!is_power_of_2(align));
1061
1062 if (unlikely(!vmap_initialized))
1063 return ERR_PTR(-EBUSY);
1064
1065 might_sleep();
1066
1067 va = kmem_cache_alloc_node(vmap_area_cachep,
1068 gfp_mask & GFP_RECLAIM_MASK, node);
1069 if (unlikely(!va))
1070 return ERR_PTR(-ENOMEM);
1071
1072 /*
1073 * Only scan the relevant parts containing pointers to other objects
1074 * to avoid false negatives.
1075 */
1076 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
1077
1078retry:
1079 /*
1080 * Preload this CPU with one extra vmap_area object to ensure
1081 * that we have it available when fit type of free area is
1082 * NE_FIT_TYPE.
1083 *
1084 * The preload is done in non-atomic context, thus it allows us
1085 * to use more permissive allocation masks to be more stable under
1086 * low memory condition and high memory pressure.
1087 *
1088 * Even if it fails we do not really care about that. Just proceed
1089 * as it is. "overflow" path will refill the cache we allocate from.
1090 */
1091 preempt_disable();
1092 if (!__this_cpu_read(ne_fit_preload_node)) {
1093 preempt_enable();
1094 pva = kmem_cache_alloc_node(vmap_area_cachep, GFP_KERNEL, node);
1095 preempt_disable();
1096
1097 if (__this_cpu_cmpxchg(ne_fit_preload_node, NULL, pva)) {
1098 if (pva)
1099 kmem_cache_free(vmap_area_cachep, pva);
1100 }
1101 }
1102
1103 spin_lock(&vmap_area_lock);
1104 preempt_enable();
1105
1106 /*
1107 * If an allocation fails, the "vend" address is
1108 * returned. Therefore trigger the overflow path.
1109 */
1110 addr = __alloc_vmap_area(size, align, vstart, vend);
1111 if (unlikely(addr == vend))
1112 goto overflow;
1113
1114 va->va_start = addr;
1115 va->va_end = addr + size;
1116 va->vm = NULL;
1117 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
1118
1119 spin_unlock(&vmap_area_lock);
1120
1121 BUG_ON(!IS_ALIGNED(va->va_start, align));
1122 BUG_ON(va->va_start < vstart);
1123 BUG_ON(va->va_end > vend);
1124
1125 return va;
1126
1127overflow:
1128 spin_unlock(&vmap_area_lock);
1129 if (!purged) {
1130 purge_vmap_area_lazy();
1131 purged = 1;
1132 goto retry;
1133 }
1134
1135 if (gfpflags_allow_blocking(gfp_mask)) {
1136 unsigned long freed = 0;
1137 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
1138 if (freed > 0) {
1139 purged = 0;
1140 goto retry;
1141 }
1142 }
1143
1144 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
1145 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
1146 size);
1147
1148 kmem_cache_free(vmap_area_cachep, va);
1149 return ERR_PTR(-EBUSY);
1150}
1151
1152int register_vmap_purge_notifier(struct notifier_block *nb)
1153{
1154 return blocking_notifier_chain_register(&vmap_notify_list, nb);
1155}
1156EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
1157
1158int unregister_vmap_purge_notifier(struct notifier_block *nb)
1159{
1160 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
1161}
1162EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
1163
1164static void __free_vmap_area(struct vmap_area *va)
1165{
1166 /*
1167 * Remove from the busy tree/list.
1168 */
1169 unlink_va(va, &vmap_area_root);
1170
1171 /*
1172 * Merge VA with its neighbors, otherwise just add it.
1173 */
1174 merge_or_add_vmap_area(va,
1175 &free_vmap_area_root, &free_vmap_area_list);
1176}
1177
1178/*
1179 * Free a region of KVA allocated by alloc_vmap_area
1180 */
1181static void free_vmap_area(struct vmap_area *va)
1182{
1183 spin_lock(&vmap_area_lock);
1184 __free_vmap_area(va);
1185 spin_unlock(&vmap_area_lock);
1186}
1187
1188/*
1189 * Clear the pagetable entries of a given vmap_area
1190 */
1191static void unmap_vmap_area(struct vmap_area *va)
1192{
1193 vunmap_page_range(va->va_start, va->va_end);
1194}
1195
1196/*
1197 * lazy_max_pages is the maximum amount of virtual address space we gather up
1198 * before attempting to purge with a TLB flush.
1199 *
1200 * There is a tradeoff here: a larger number will cover more kernel page tables
1201 * and take slightly longer to purge, but it will linearly reduce the number of
1202 * global TLB flushes that must be performed. It would seem natural to scale
1203 * this number up linearly with the number of CPUs (because vmapping activity
1204 * could also scale linearly with the number of CPUs), however it is likely
1205 * that in practice, workloads might be constrained in other ways that mean
1206 * vmap activity will not scale linearly with CPUs. Also, I want to be
1207 * conservative and not introduce a big latency on huge systems, so go with
1208 * a less aggressive log scale. It will still be an improvement over the old
1209 * code, and it will be simple to change the scale factor if we find that it
1210 * becomes a problem on bigger systems.
1211 */
1212static unsigned long lazy_max_pages(void)
1213{
1214 unsigned int log;
1215
1216 log = fls(num_online_cpus());
1217
1218 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
1219}
1220
1221static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
1222
1223/*
1224 * Serialize vmap purging. There is no actual criticial section protected
1225 * by this look, but we want to avoid concurrent calls for performance
1226 * reasons and to make the pcpu_get_vm_areas more deterministic.
1227 */
1228static DEFINE_MUTEX(vmap_purge_lock);
1229
1230/* for per-CPU blocks */
1231static void purge_fragmented_blocks_allcpus(void);
1232
1233/*
1234 * called before a call to iounmap() if the caller wants vm_area_struct's
1235 * immediately freed.
1236 */
1237void set_iounmap_nonlazy(void)
1238{
1239 atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1);
1240}
1241
1242/*
1243 * Purges all lazily-freed vmap areas.
1244 */
1245static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
1246{
1247 unsigned long resched_threshold;
1248 struct llist_node *valist;
1249 struct vmap_area *va;
1250 struct vmap_area *n_va;
1251
1252 lockdep_assert_held(&vmap_purge_lock);
1253
1254 valist = llist_del_all(&vmap_purge_list);
1255 if (unlikely(valist == NULL))
1256 return false;
1257
1258 /*
1259 * First make sure the mappings are removed from all page-tables
1260 * before they are freed.
1261 */
1262 vmalloc_sync_all();
1263
1264 /*
1265 * TODO: to calculate a flush range without looping.
1266 * The list can be up to lazy_max_pages() elements.
1267 */
1268 llist_for_each_entry(va, valist, purge_list) {
1269 if (va->va_start < start)
1270 start = va->va_start;
1271 if (va->va_end > end)
1272 end = va->va_end;
1273 }
1274
1275 flush_tlb_kernel_range(start, end);
1276 resched_threshold = lazy_max_pages() << 1;
1277
1278 spin_lock(&vmap_area_lock);
1279 llist_for_each_entry_safe(va, n_va, valist, purge_list) {
1280 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
1281
1282 /*
1283 * Finally insert or merge lazily-freed area. It is
1284 * detached and there is no need to "unlink" it from
1285 * anything.
1286 */
1287 merge_or_add_vmap_area(va,
1288 &free_vmap_area_root, &free_vmap_area_list);
1289
1290 atomic_long_sub(nr, &vmap_lazy_nr);
1291
1292 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
1293 cond_resched_lock(&vmap_area_lock);
1294 }
1295 spin_unlock(&vmap_area_lock);
1296 return true;
1297}
1298
1299/*
1300 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
1301 * is already purging.
1302 */
1303static void try_purge_vmap_area_lazy(void)
1304{
1305 if (mutex_trylock(&vmap_purge_lock)) {
1306 __purge_vmap_area_lazy(ULONG_MAX, 0);
1307 mutex_unlock(&vmap_purge_lock);
1308 }
1309}
1310
1311/*
1312 * Kick off a purge of the outstanding lazy areas.
1313 */
1314static void purge_vmap_area_lazy(void)
1315{
1316 mutex_lock(&vmap_purge_lock);
1317 purge_fragmented_blocks_allcpus();
1318 __purge_vmap_area_lazy(ULONG_MAX, 0);
1319 mutex_unlock(&vmap_purge_lock);
1320}
1321
1322/*
1323 * Free a vmap area, caller ensuring that the area has been unmapped
1324 * and flush_cache_vunmap had been called for the correct range
1325 * previously.
1326 */
1327static void free_vmap_area_noflush(struct vmap_area *va)
1328{
1329 unsigned long nr_lazy;
1330
1331 spin_lock(&vmap_area_lock);
1332 unlink_va(va, &vmap_area_root);
1333 spin_unlock(&vmap_area_lock);
1334
1335 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
1336 PAGE_SHIFT, &vmap_lazy_nr);
1337
1338 /* After this point, we may free va at any time */
1339 llist_add(&va->purge_list, &vmap_purge_list);
1340
1341 if (unlikely(nr_lazy > lazy_max_pages()))
1342 try_purge_vmap_area_lazy();
1343}
1344
1345/*
1346 * Free and unmap a vmap area
1347 */
1348static void free_unmap_vmap_area(struct vmap_area *va)
1349{
1350 flush_cache_vunmap(va->va_start, va->va_end);
1351 unmap_vmap_area(va);
1352 if (debug_pagealloc_enabled())
1353 flush_tlb_kernel_range(va->va_start, va->va_end);
1354
1355 free_vmap_area_noflush(va);
1356}
1357
1358static struct vmap_area *find_vmap_area(unsigned long addr)
1359{
1360 struct vmap_area *va;
1361
1362 spin_lock(&vmap_area_lock);
1363 va = __find_vmap_area(addr);
1364 spin_unlock(&vmap_area_lock);
1365
1366 return va;
1367}
1368
1369/*** Per cpu kva allocator ***/
1370
1371/*
1372 * vmap space is limited especially on 32 bit architectures. Ensure there is
1373 * room for at least 16 percpu vmap blocks per CPU.
1374 */
1375/*
1376 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
1377 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
1378 * instead (we just need a rough idea)
1379 */
1380#if BITS_PER_LONG == 32
1381#define VMALLOC_SPACE (128UL*1024*1024)
1382#else
1383#define VMALLOC_SPACE (128UL*1024*1024*1024)
1384#endif
1385
1386#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
1387#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
1388#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
1389#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
1390#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
1391#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
1392#define VMAP_BBMAP_BITS \
1393 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
1394 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
1395 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
1396
1397#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
1398
1399struct vmap_block_queue {
1400 spinlock_t lock;
1401 struct list_head free;
1402};
1403
1404struct vmap_block {
1405 spinlock_t lock;
1406 struct vmap_area *va;
1407 unsigned long free, dirty;
1408 unsigned long dirty_min, dirty_max; /*< dirty range */
1409 struct list_head free_list;
1410 struct rcu_head rcu_head;
1411 struct list_head purge;
1412};
1413
1414/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
1415static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
1416
1417/*
1418 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
1419 * in the free path. Could get rid of this if we change the API to return a
1420 * "cookie" from alloc, to be passed to free. But no big deal yet.
1421 */
1422static DEFINE_SPINLOCK(vmap_block_tree_lock);
1423static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
1424
1425/*
1426 * We should probably have a fallback mechanism to allocate virtual memory
1427 * out of partially filled vmap blocks. However vmap block sizing should be
1428 * fairly reasonable according to the vmalloc size, so it shouldn't be a
1429 * big problem.
1430 */
1431
1432static unsigned long addr_to_vb_idx(unsigned long addr)
1433{
1434 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
1435 addr /= VMAP_BLOCK_SIZE;
1436 return addr;
1437}
1438
1439static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
1440{
1441 unsigned long addr;
1442
1443 addr = va_start + (pages_off << PAGE_SHIFT);
1444 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
1445 return (void *)addr;
1446}
1447
1448/**
1449 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
1450 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
1451 * @order: how many 2^order pages should be occupied in newly allocated block
1452 * @gfp_mask: flags for the page level allocator
1453 *
1454 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
1455 */
1456static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
1457{
1458 struct vmap_block_queue *vbq;
1459 struct vmap_block *vb;
1460 struct vmap_area *va;
1461 unsigned long vb_idx;
1462 int node, err;
1463 void *vaddr;
1464
1465 node = numa_node_id();
1466
1467 vb = kmalloc_node(sizeof(struct vmap_block),
1468 gfp_mask & GFP_RECLAIM_MASK, node);
1469 if (unlikely(!vb))
1470 return ERR_PTR(-ENOMEM);
1471
1472 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
1473 VMALLOC_START, VMALLOC_END,
1474 node, gfp_mask);
1475 if (IS_ERR(va)) {
1476 kfree(vb);
1477 return ERR_CAST(va);
1478 }
1479
1480 err = radix_tree_preload(gfp_mask);
1481 if (unlikely(err)) {
1482 kfree(vb);
1483 free_vmap_area(va);
1484 return ERR_PTR(err);
1485 }
1486
1487 vaddr = vmap_block_vaddr(va->va_start, 0);
1488 spin_lock_init(&vb->lock);
1489 vb->va = va;
1490 /* At least something should be left free */
1491 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
1492 vb->free = VMAP_BBMAP_BITS - (1UL << order);
1493 vb->dirty = 0;
1494 vb->dirty_min = VMAP_BBMAP_BITS;
1495 vb->dirty_max = 0;
1496 INIT_LIST_HEAD(&vb->free_list);
1497
1498 vb_idx = addr_to_vb_idx(va->va_start);
1499 spin_lock(&vmap_block_tree_lock);
1500 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
1501 spin_unlock(&vmap_block_tree_lock);
1502 BUG_ON(err);
1503 radix_tree_preload_end();
1504
1505 vbq = &get_cpu_var(vmap_block_queue);
1506 spin_lock(&vbq->lock);
1507 list_add_tail_rcu(&vb->free_list, &vbq->free);
1508 spin_unlock(&vbq->lock);
1509 put_cpu_var(vmap_block_queue);
1510
1511 return vaddr;
1512}
1513
1514static void free_vmap_block(struct vmap_block *vb)
1515{
1516 struct vmap_block *tmp;
1517 unsigned long vb_idx;
1518
1519 vb_idx = addr_to_vb_idx(vb->va->va_start);
1520 spin_lock(&vmap_block_tree_lock);
1521 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
1522 spin_unlock(&vmap_block_tree_lock);
1523 BUG_ON(tmp != vb);
1524
1525 free_vmap_area_noflush(vb->va);
1526 kfree_rcu(vb, rcu_head);
1527}
1528
1529static void purge_fragmented_blocks(int cpu)
1530{
1531 LIST_HEAD(purge);
1532 struct vmap_block *vb;
1533 struct vmap_block *n_vb;
1534 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1535
1536 rcu_read_lock();
1537 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1538
1539 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
1540 continue;
1541
1542 spin_lock(&vb->lock);
1543 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
1544 vb->free = 0; /* prevent further allocs after releasing lock */
1545 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
1546 vb->dirty_min = 0;
1547 vb->dirty_max = VMAP_BBMAP_BITS;
1548 spin_lock(&vbq->lock);
1549 list_del_rcu(&vb->free_list);
1550 spin_unlock(&vbq->lock);
1551 spin_unlock(&vb->lock);
1552 list_add_tail(&vb->purge, &purge);
1553 } else
1554 spin_unlock(&vb->lock);
1555 }
1556 rcu_read_unlock();
1557
1558 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
1559 list_del(&vb->purge);
1560 free_vmap_block(vb);
1561 }
1562}
1563
1564static void purge_fragmented_blocks_allcpus(void)
1565{
1566 int cpu;
1567
1568 for_each_possible_cpu(cpu)
1569 purge_fragmented_blocks(cpu);
1570}
1571
1572static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
1573{
1574 struct vmap_block_queue *vbq;
1575 struct vmap_block *vb;
1576 void *vaddr = NULL;
1577 unsigned int order;
1578
1579 BUG_ON(offset_in_page(size));
1580 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
1581 if (WARN_ON(size == 0)) {
1582 /*
1583 * Allocating 0 bytes isn't what caller wants since
1584 * get_order(0) returns funny result. Just warn and terminate
1585 * early.
1586 */
1587 return NULL;
1588 }
1589 order = get_order(size);
1590
1591 rcu_read_lock();
1592 vbq = &get_cpu_var(vmap_block_queue);
1593 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1594 unsigned long pages_off;
1595
1596 spin_lock(&vb->lock);
1597 if (vb->free < (1UL << order)) {
1598 spin_unlock(&vb->lock);
1599 continue;
1600 }
1601
1602 pages_off = VMAP_BBMAP_BITS - vb->free;
1603 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
1604 vb->free -= 1UL << order;
1605 if (vb->free == 0) {
1606 spin_lock(&vbq->lock);
1607 list_del_rcu(&vb->free_list);
1608 spin_unlock(&vbq->lock);
1609 }
1610
1611 spin_unlock(&vb->lock);
1612 break;
1613 }
1614
1615 put_cpu_var(vmap_block_queue);
1616 rcu_read_unlock();
1617
1618 /* Allocate new block if nothing was found */
1619 if (!vaddr)
1620 vaddr = new_vmap_block(order, gfp_mask);
1621
1622 return vaddr;
1623}
1624
1625static void vb_free(const void *addr, unsigned long size)
1626{
1627 unsigned long offset;
1628 unsigned long vb_idx;
1629 unsigned int order;
1630 struct vmap_block *vb;
1631
1632 BUG_ON(offset_in_page(size));
1633 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
1634
1635 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
1636
1637 order = get_order(size);
1638
1639 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
1640 offset >>= PAGE_SHIFT;
1641
1642 vb_idx = addr_to_vb_idx((unsigned long)addr);
1643 rcu_read_lock();
1644 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
1645 rcu_read_unlock();
1646 BUG_ON(!vb);
1647
1648 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
1649
1650 if (debug_pagealloc_enabled())
1651 flush_tlb_kernel_range((unsigned long)addr,
1652 (unsigned long)addr + size);
1653
1654 spin_lock(&vb->lock);
1655
1656 /* Expand dirty range */
1657 vb->dirty_min = min(vb->dirty_min, offset);
1658 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
1659
1660 vb->dirty += 1UL << order;
1661 if (vb->dirty == VMAP_BBMAP_BITS) {
1662 BUG_ON(vb->free);
1663 spin_unlock(&vb->lock);
1664 free_vmap_block(vb);
1665 } else
1666 spin_unlock(&vb->lock);
1667}
1668
1669static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
1670{
1671 int cpu;
1672
1673 if (unlikely(!vmap_initialized))
1674 return;
1675
1676 might_sleep();
1677
1678 for_each_possible_cpu(cpu) {
1679 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1680 struct vmap_block *vb;
1681
1682 rcu_read_lock();
1683 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1684 spin_lock(&vb->lock);
1685 if (vb->dirty) {
1686 unsigned long va_start = vb->va->va_start;
1687 unsigned long s, e;
1688
1689 s = va_start + (vb->dirty_min << PAGE_SHIFT);
1690 e = va_start + (vb->dirty_max << PAGE_SHIFT);
1691
1692 start = min(s, start);
1693 end = max(e, end);
1694
1695 flush = 1;
1696 }
1697 spin_unlock(&vb->lock);
1698 }
1699 rcu_read_unlock();
1700 }
1701
1702 mutex_lock(&vmap_purge_lock);
1703 purge_fragmented_blocks_allcpus();
1704 if (!__purge_vmap_area_lazy(start, end) && flush)
1705 flush_tlb_kernel_range(start, end);
1706 mutex_unlock(&vmap_purge_lock);
1707}
1708
1709/**
1710 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1711 *
1712 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1713 * to amortize TLB flushing overheads. What this means is that any page you
1714 * have now, may, in a former life, have been mapped into kernel virtual
1715 * address by the vmap layer and so there might be some CPUs with TLB entries
1716 * still referencing that page (additional to the regular 1:1 kernel mapping).
1717 *
1718 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1719 * be sure that none of the pages we have control over will have any aliases
1720 * from the vmap layer.
1721 */
1722void vm_unmap_aliases(void)
1723{
1724 unsigned long start = ULONG_MAX, end = 0;
1725 int flush = 0;
1726
1727 _vm_unmap_aliases(start, end, flush);
1728}
1729EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1730
1731/**
1732 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1733 * @mem: the pointer returned by vm_map_ram
1734 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1735 */
1736void vm_unmap_ram(const void *mem, unsigned int count)
1737{
1738 unsigned long size = (unsigned long)count << PAGE_SHIFT;
1739 unsigned long addr = (unsigned long)mem;
1740 struct vmap_area *va;
1741
1742 might_sleep();
1743 BUG_ON(!addr);
1744 BUG_ON(addr < VMALLOC_START);
1745 BUG_ON(addr > VMALLOC_END);
1746 BUG_ON(!PAGE_ALIGNED(addr));
1747
1748 if (likely(count <= VMAP_MAX_ALLOC)) {
1749 debug_check_no_locks_freed(mem, size);
1750 vb_free(mem, size);
1751 return;
1752 }
1753
1754 va = find_vmap_area(addr);
1755 BUG_ON(!va);
1756 debug_check_no_locks_freed((void *)va->va_start,
1757 (va->va_end - va->va_start));
1758 free_unmap_vmap_area(va);
1759}
1760EXPORT_SYMBOL(vm_unmap_ram);
1761
1762/**
1763 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1764 * @pages: an array of pointers to the pages to be mapped
1765 * @count: number of pages
1766 * @node: prefer to allocate data structures on this node
1767 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1768 *
1769 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
1770 * faster than vmap so it's good. But if you mix long-life and short-life
1771 * objects with vm_map_ram(), it could consume lots of address space through
1772 * fragmentation (especially on a 32bit machine). You could see failures in
1773 * the end. Please use this function for short-lived objects.
1774 *
1775 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1776 */
1777void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1778{
1779 unsigned long size = (unsigned long)count << PAGE_SHIFT;
1780 unsigned long addr;
1781 void *mem;
1782
1783 if (likely(count <= VMAP_MAX_ALLOC)) {
1784 mem = vb_alloc(size, GFP_KERNEL);
1785 if (IS_ERR(mem))
1786 return NULL;
1787 addr = (unsigned long)mem;
1788 } else {
1789 struct vmap_area *va;
1790 va = alloc_vmap_area(size, PAGE_SIZE,
1791 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1792 if (IS_ERR(va))
1793 return NULL;
1794
1795 addr = va->va_start;
1796 mem = (void *)addr;
1797 }
1798 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1799 vm_unmap_ram(mem, count);
1800 return NULL;
1801 }
1802 return mem;
1803}
1804EXPORT_SYMBOL(vm_map_ram);
1805
1806static struct vm_struct *vmlist __initdata;
1807
1808/**
1809 * vm_area_add_early - add vmap area early during boot
1810 * @vm: vm_struct to add
1811 *
1812 * This function is used to add fixed kernel vm area to vmlist before
1813 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1814 * should contain proper values and the other fields should be zero.
1815 *
1816 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1817 */
1818void __init vm_area_add_early(struct vm_struct *vm)
1819{
1820 struct vm_struct *tmp, **p;
1821
1822 BUG_ON(vmap_initialized);
1823 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1824 if (tmp->addr >= vm->addr) {
1825 BUG_ON(tmp->addr < vm->addr + vm->size);
1826 break;
1827 } else
1828 BUG_ON(tmp->addr + tmp->size > vm->addr);
1829 }
1830 vm->next = *p;
1831 *p = vm;
1832}
1833
1834/**
1835 * vm_area_register_early - register vmap area early during boot
1836 * @vm: vm_struct to register
1837 * @align: requested alignment
1838 *
1839 * This function is used to register kernel vm area before
1840 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1841 * proper values on entry and other fields should be zero. On return,
1842 * vm->addr contains the allocated address.
1843 *
1844 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1845 */
1846void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1847{
1848 static size_t vm_init_off __initdata;
1849 unsigned long addr;
1850
1851 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1852 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1853
1854 vm->addr = (void *)addr;
1855
1856 vm_area_add_early(vm);
1857}
1858
1859static void vmap_init_free_space(void)
1860{
1861 unsigned long vmap_start = 1;
1862 const unsigned long vmap_end = ULONG_MAX;
1863 struct vmap_area *busy, *free;
1864
1865 /*
1866 * B F B B B F
1867 * -|-----|.....|-----|-----|-----|.....|-
1868 * | The KVA space |
1869 * |<--------------------------------->|
1870 */
1871 list_for_each_entry(busy, &vmap_area_list, list) {
1872 if (busy->va_start - vmap_start > 0) {
1873 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
1874 if (!WARN_ON_ONCE(!free)) {
1875 free->va_start = vmap_start;
1876 free->va_end = busy->va_start;
1877
1878 insert_vmap_area_augment(free, NULL,
1879 &free_vmap_area_root,
1880 &free_vmap_area_list);
1881 }
1882 }
1883
1884 vmap_start = busy->va_end;
1885 }
1886
1887 if (vmap_end - vmap_start > 0) {
1888 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
1889 if (!WARN_ON_ONCE(!free)) {
1890 free->va_start = vmap_start;
1891 free->va_end = vmap_end;
1892
1893 insert_vmap_area_augment(free, NULL,
1894 &free_vmap_area_root,
1895 &free_vmap_area_list);
1896 }
1897 }
1898}
1899
1900void __init vmalloc_init(void)
1901{
1902 struct vmap_area *va;
1903 struct vm_struct *tmp;
1904 int i;
1905
1906 /*
1907 * Create the cache for vmap_area objects.
1908 */
1909 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
1910
1911 for_each_possible_cpu(i) {
1912 struct vmap_block_queue *vbq;
1913 struct vfree_deferred *p;
1914
1915 vbq = &per_cpu(vmap_block_queue, i);
1916 spin_lock_init(&vbq->lock);
1917 INIT_LIST_HEAD(&vbq->free);
1918 p = &per_cpu(vfree_deferred, i);
1919 init_llist_head(&p->list);
1920 INIT_WORK(&p->wq, free_work);
1921 }
1922
1923 /* Import existing vmlist entries. */
1924 for (tmp = vmlist; tmp; tmp = tmp->next) {
1925 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
1926 if (WARN_ON_ONCE(!va))
1927 continue;
1928
1929 va->va_start = (unsigned long)tmp->addr;
1930 va->va_end = va->va_start + tmp->size;
1931 va->vm = tmp;
1932 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
1933 }
1934
1935 /*
1936 * Now we can initialize a free vmap space.
1937 */
1938 vmap_init_free_space();
1939 vmap_initialized = true;
1940}
1941
1942/**
1943 * map_kernel_range_noflush - map kernel VM area with the specified pages
1944 * @addr: start of the VM area to map
1945 * @size: size of the VM area to map
1946 * @prot: page protection flags to use
1947 * @pages: pages to map
1948 *
1949 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1950 * specify should have been allocated using get_vm_area() and its
1951 * friends.
1952 *
1953 * NOTE:
1954 * This function does NOT do any cache flushing. The caller is
1955 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1956 * before calling this function.
1957 *
1958 * RETURNS:
1959 * The number of pages mapped on success, -errno on failure.
1960 */
1961int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1962 pgprot_t prot, struct page **pages)
1963{
1964 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1965}
1966
1967/**
1968 * unmap_kernel_range_noflush - unmap kernel VM area
1969 * @addr: start of the VM area to unmap
1970 * @size: size of the VM area to unmap
1971 *
1972 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1973 * specify should have been allocated using get_vm_area() and its
1974 * friends.
1975 *
1976 * NOTE:
1977 * This function does NOT do any cache flushing. The caller is
1978 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1979 * before calling this function and flush_tlb_kernel_range() after.
1980 */
1981void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1982{
1983 vunmap_page_range(addr, addr + size);
1984}
1985EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1986
1987/**
1988 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1989 * @addr: start of the VM area to unmap
1990 * @size: size of the VM area to unmap
1991 *
1992 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1993 * the unmapping and tlb after.
1994 */
1995void unmap_kernel_range(unsigned long addr, unsigned long size)
1996{
1997 unsigned long end = addr + size;
1998
1999 flush_cache_vunmap(addr, end);
2000 vunmap_page_range(addr, end);
2001 flush_tlb_kernel_range(addr, end);
2002}
2003EXPORT_SYMBOL_GPL(unmap_kernel_range);
2004
2005int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
2006{
2007 unsigned long addr = (unsigned long)area->addr;
2008 unsigned long end = addr + get_vm_area_size(area);
2009 int err;
2010
2011 err = vmap_page_range(addr, end, prot, pages);
2012
2013 return err > 0 ? 0 : err;
2014}
2015EXPORT_SYMBOL_GPL(map_vm_area);
2016
2017static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
2018 unsigned long flags, const void *caller)
2019{
2020 spin_lock(&vmap_area_lock);
2021 vm->flags = flags;
2022 vm->addr = (void *)va->va_start;
2023 vm->size = va->va_end - va->va_start;
2024 vm->caller = caller;
2025 va->vm = vm;
2026 spin_unlock(&vmap_area_lock);
2027}
2028
2029static void clear_vm_uninitialized_flag(struct vm_struct *vm)
2030{
2031 /*
2032 * Before removing VM_UNINITIALIZED,
2033 * we should make sure that vm has proper values.
2034 * Pair with smp_rmb() in show_numa_info().
2035 */
2036 smp_wmb();
2037 vm->flags &= ~VM_UNINITIALIZED;
2038}
2039
2040static struct vm_struct *__get_vm_area_node(unsigned long size,
2041 unsigned long align, unsigned long flags, unsigned long start,
2042 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
2043{
2044 struct vmap_area *va;
2045 struct vm_struct *area;
2046
2047 BUG_ON(in_interrupt());
2048 size = PAGE_ALIGN(size);
2049 if (unlikely(!size))
2050 return NULL;
2051
2052 if (flags & VM_IOREMAP)
2053 align = 1ul << clamp_t(int, get_count_order_long(size),
2054 PAGE_SHIFT, IOREMAP_MAX_ORDER);
2055
2056 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
2057 if (unlikely(!area))
2058 return NULL;
2059
2060 if (!(flags & VM_NO_GUARD))
2061 size += PAGE_SIZE;
2062
2063 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
2064 if (IS_ERR(va)) {
2065 kfree(area);
2066 return NULL;
2067 }
2068
2069 setup_vmalloc_vm(area, va, flags, caller);
2070
2071 return area;
2072}
2073
2074struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
2075 unsigned long start, unsigned long end)
2076{
2077 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
2078 GFP_KERNEL, __builtin_return_address(0));
2079}
2080EXPORT_SYMBOL_GPL(__get_vm_area);
2081
2082struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
2083 unsigned long start, unsigned long end,
2084 const void *caller)
2085{
2086 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
2087 GFP_KERNEL, caller);
2088}
2089
2090/**
2091 * get_vm_area - reserve a contiguous kernel virtual area
2092 * @size: size of the area
2093 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
2094 *
2095 * Search an area of @size in the kernel virtual mapping area,
2096 * and reserved it for out purposes. Returns the area descriptor
2097 * on success or %NULL on failure.
2098 *
2099 * Return: the area descriptor on success or %NULL on failure.
2100 */
2101struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
2102{
2103 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
2104 NUMA_NO_NODE, GFP_KERNEL,
2105 __builtin_return_address(0));
2106}
2107
2108struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
2109 const void *caller)
2110{
2111 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
2112 NUMA_NO_NODE, GFP_KERNEL, caller);
2113}
2114
2115/**
2116 * find_vm_area - find a continuous kernel virtual area
2117 * @addr: base address
2118 *
2119 * Search for the kernel VM area starting at @addr, and return it.
2120 * It is up to the caller to do all required locking to keep the returned
2121 * pointer valid.
2122 *
2123 * Return: pointer to the found area or %NULL on faulure
2124 */
2125struct vm_struct *find_vm_area(const void *addr)
2126{
2127 struct vmap_area *va;
2128
2129 va = find_vmap_area((unsigned long)addr);
2130 if (!va)
2131 return NULL;
2132
2133 return va->vm;
2134}
2135
2136/**
2137 * remove_vm_area - find and remove a continuous kernel virtual area
2138 * @addr: base address
2139 *
2140 * Search for the kernel VM area starting at @addr, and remove it.
2141 * This function returns the found VM area, but using it is NOT safe
2142 * on SMP machines, except for its size or flags.
2143 *
2144 * Return: pointer to the found area or %NULL on faulure
2145 */
2146struct vm_struct *remove_vm_area(const void *addr)
2147{
2148 struct vmap_area *va;
2149
2150 might_sleep();
2151
2152 spin_lock(&vmap_area_lock);
2153 va = __find_vmap_area((unsigned long)addr);
2154 if (va && va->vm) {
2155 struct vm_struct *vm = va->vm;
2156
2157 va->vm = NULL;
2158 spin_unlock(&vmap_area_lock);
2159
2160 kasan_free_shadow(vm);
2161 free_unmap_vmap_area(va);
2162
2163 return vm;
2164 }
2165
2166 spin_unlock(&vmap_area_lock);
2167 return NULL;
2168}
2169
2170static inline void set_area_direct_map(const struct vm_struct *area,
2171 int (*set_direct_map)(struct page *page))
2172{
2173 int i;
2174
2175 for (i = 0; i < area->nr_pages; i++)
2176 if (page_address(area->pages[i]))
2177 set_direct_map(area->pages[i]);
2178}
2179
2180/* Handle removing and resetting vm mappings related to the vm_struct. */
2181static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
2182{
2183 unsigned long start = ULONG_MAX, end = 0;
2184 int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
2185 int flush_dmap = 0;
2186 int i;
2187
2188 remove_vm_area(area->addr);
2189
2190 /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
2191 if (!flush_reset)
2192 return;
2193
2194 /*
2195 * If not deallocating pages, just do the flush of the VM area and
2196 * return.
2197 */
2198 if (!deallocate_pages) {
2199 vm_unmap_aliases();
2200 return;
2201 }
2202
2203 /*
2204 * If execution gets here, flush the vm mapping and reset the direct
2205 * map. Find the start and end range of the direct mappings to make sure
2206 * the vm_unmap_aliases() flush includes the direct map.
2207 */
2208 for (i = 0; i < area->nr_pages; i++) {
2209 unsigned long addr = (unsigned long)page_address(area->pages[i]);
2210 if (addr) {
2211 start = min(addr, start);
2212 end = max(addr + PAGE_SIZE, end);
2213 flush_dmap = 1;
2214 }
2215 }
2216
2217 /*
2218 * Set direct map to something invalid so that it won't be cached if
2219 * there are any accesses after the TLB flush, then flush the TLB and
2220 * reset the direct map permissions to the default.
2221 */
2222 set_area_direct_map(area, set_direct_map_invalid_noflush);
2223 _vm_unmap_aliases(start, end, flush_dmap);
2224 set_area_direct_map(area, set_direct_map_default_noflush);
2225}
2226
2227static void __vunmap(const void *addr, int deallocate_pages)
2228{
2229 struct vm_struct *area;
2230
2231 if (!addr)
2232 return;
2233
2234 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
2235 addr))
2236 return;
2237
2238 area = find_vm_area(addr);
2239 if (unlikely(!area)) {
2240 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
2241 addr);
2242 return;
2243 }
2244
2245 debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
2246 debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
2247
2248 vm_remove_mappings(area, deallocate_pages);
2249
2250 if (deallocate_pages) {
2251 int i;
2252
2253 for (i = 0; i < area->nr_pages; i++) {
2254 struct page *page = area->pages[i];
2255
2256 BUG_ON(!page);
2257 __free_pages(page, 0);
2258 }
2259 atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
2260
2261 kvfree(area->pages);
2262 }
2263
2264 kfree(area);
2265 return;
2266}
2267
2268static inline void __vfree_deferred(const void *addr)
2269{
2270 /*
2271 * Use raw_cpu_ptr() because this can be called from preemptible
2272 * context. Preemption is absolutely fine here, because the llist_add()
2273 * implementation is lockless, so it works even if we are adding to
2274 * nother cpu's list. schedule_work() should be fine with this too.
2275 */
2276 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
2277
2278 if (llist_add((struct llist_node *)addr, &p->list))
2279 schedule_work(&p->wq);
2280}
2281
2282/**
2283 * vfree_atomic - release memory allocated by vmalloc()
2284 * @addr: memory base address
2285 *
2286 * This one is just like vfree() but can be called in any atomic context
2287 * except NMIs.
2288 */
2289void vfree_atomic(const void *addr)
2290{
2291 BUG_ON(in_nmi());
2292
2293 kmemleak_free(addr);
2294
2295 if (!addr)
2296 return;
2297 __vfree_deferred(addr);
2298}
2299
2300static void __vfree(const void *addr)
2301{
2302 if (unlikely(in_interrupt()))
2303 __vfree_deferred(addr);
2304 else
2305 __vunmap(addr, 1);
2306}
2307
2308/**
2309 * vfree - release memory allocated by vmalloc()
2310 * @addr: memory base address
2311 *
2312 * Free the virtually continuous memory area starting at @addr, as
2313 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
2314 * NULL, no operation is performed.
2315 *
2316 * Must not be called in NMI context (strictly speaking, only if we don't
2317 * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
2318 * conventions for vfree() arch-depenedent would be a really bad idea)
2319 *
2320 * May sleep if called *not* from interrupt context.
2321 *
2322 * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
2323 */
2324void vfree(const void *addr)
2325{
2326 BUG_ON(in_nmi());
2327
2328 kmemleak_free(addr);
2329
2330 might_sleep_if(!in_interrupt());
2331
2332 if (!addr)
2333 return;
2334
2335 __vfree(addr);
2336}
2337EXPORT_SYMBOL(vfree);
2338
2339/**
2340 * vunmap - release virtual mapping obtained by vmap()
2341 * @addr: memory base address
2342 *
2343 * Free the virtually contiguous memory area starting at @addr,
2344 * which was created from the page array passed to vmap().
2345 *
2346 * Must not be called in interrupt context.
2347 */
2348void vunmap(const void *addr)
2349{
2350 BUG_ON(in_interrupt());
2351 might_sleep();
2352 if (addr)
2353 __vunmap(addr, 0);
2354}
2355EXPORT_SYMBOL(vunmap);
2356
2357/**
2358 * vmap - map an array of pages into virtually contiguous space
2359 * @pages: array of page pointers
2360 * @count: number of pages to map
2361 * @flags: vm_area->flags
2362 * @prot: page protection for the mapping
2363 *
2364 * Maps @count pages from @pages into contiguous kernel virtual
2365 * space.
2366 *
2367 * Return: the address of the area or %NULL on failure
2368 */
2369void *vmap(struct page **pages, unsigned int count,
2370 unsigned long flags, pgprot_t prot)
2371{
2372 struct vm_struct *area;
2373 unsigned long size; /* In bytes */
2374
2375 might_sleep();
2376
2377 if (count > totalram_pages())
2378 return NULL;
2379
2380 size = (unsigned long)count << PAGE_SHIFT;
2381 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
2382 if (!area)
2383 return NULL;
2384
2385 if (map_vm_area(area, prot, pages)) {
2386 vunmap(area->addr);
2387 return NULL;
2388 }
2389
2390 return area->addr;
2391}
2392EXPORT_SYMBOL(vmap);
2393
2394static void *__vmalloc_node(unsigned long size, unsigned long align,
2395 gfp_t gfp_mask, pgprot_t prot,
2396 int node, const void *caller);
2397static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
2398 pgprot_t prot, int node)
2399{
2400 struct page **pages;
2401 unsigned int nr_pages, array_size, i;
2402 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
2403 const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
2404 const gfp_t highmem_mask = (gfp_mask & (GFP_DMA | GFP_DMA32)) ?
2405 0 :
2406 __GFP_HIGHMEM;
2407
2408 nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
2409 array_size = (nr_pages * sizeof(struct page *));
2410
2411 /* Please note that the recursion is strictly bounded. */
2412 if (array_size > PAGE_SIZE) {
2413 pages = __vmalloc_node(array_size, 1, nested_gfp|highmem_mask,
2414 PAGE_KERNEL, node, area->caller);
2415 } else {
2416 pages = kmalloc_node(array_size, nested_gfp, node);
2417 }
2418
2419 if (!pages) {
2420 remove_vm_area(area->addr);
2421 kfree(area);
2422 return NULL;
2423 }
2424
2425 area->pages = pages;
2426 area->nr_pages = nr_pages;
2427
2428 for (i = 0; i < area->nr_pages; i++) {
2429 struct page *page;
2430
2431 if (node == NUMA_NO_NODE)
2432 page = alloc_page(alloc_mask|highmem_mask);
2433 else
2434 page = alloc_pages_node(node, alloc_mask|highmem_mask, 0);
2435
2436 if (unlikely(!page)) {
2437 /* Successfully allocated i pages, free them in __vunmap() */
2438 area->nr_pages = i;
2439 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
2440 goto fail;
2441 }
2442 area->pages[i] = page;
2443 if (gfpflags_allow_blocking(gfp_mask|highmem_mask))
2444 cond_resched();
2445 }
2446 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
2447
2448 if (map_vm_area(area, prot, pages))
2449 goto fail;
2450 return area->addr;
2451
2452fail:
2453 warn_alloc(gfp_mask, NULL,
2454 "vmalloc: allocation failure, allocated %ld of %ld bytes",
2455 (area->nr_pages*PAGE_SIZE), area->size);
2456 __vfree(area->addr);
2457 return NULL;
2458}
2459
2460/**
2461 * __vmalloc_node_range - allocate virtually contiguous memory
2462 * @size: allocation size
2463 * @align: desired alignment
2464 * @start: vm area range start
2465 * @end: vm area range end
2466 * @gfp_mask: flags for the page level allocator
2467 * @prot: protection mask for the allocated pages
2468 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
2469 * @node: node to use for allocation or NUMA_NO_NODE
2470 * @caller: caller's return address
2471 *
2472 * Allocate enough pages to cover @size from the page level
2473 * allocator with @gfp_mask flags. Map them into contiguous
2474 * kernel virtual space, using a pagetable protection of @prot.
2475 *
2476 * Return: the address of the area or %NULL on failure
2477 */
2478void *__vmalloc_node_range(unsigned long size, unsigned long align,
2479 unsigned long start, unsigned long end, gfp_t gfp_mask,
2480 pgprot_t prot, unsigned long vm_flags, int node,
2481 const void *caller)
2482{
2483 struct vm_struct *area;
2484 void *addr;
2485 unsigned long real_size = size;
2486
2487 size = PAGE_ALIGN(size);
2488 if (!size || (size >> PAGE_SHIFT) > totalram_pages())
2489 goto fail;
2490
2491 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
2492 vm_flags, start, end, node, gfp_mask, caller);
2493 if (!area)
2494 goto fail;
2495
2496 addr = __vmalloc_area_node(area, gfp_mask, prot, node);
2497 if (!addr)
2498 return NULL;
2499
2500 /*
2501 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
2502 * flag. It means that vm_struct is not fully initialized.
2503 * Now, it is fully initialized, so remove this flag here.
2504 */
2505 clear_vm_uninitialized_flag(area);
2506
2507 kmemleak_vmalloc(area, size, gfp_mask);
2508
2509 return addr;
2510
2511fail:
2512 warn_alloc(gfp_mask, NULL,
2513 "vmalloc: allocation failure: %lu bytes", real_size);
2514 return NULL;
2515}
2516
2517/*
2518 * This is only for performance analysis of vmalloc and stress purpose.
2519 * It is required by vmalloc test module, therefore do not use it other
2520 * than that.
2521 */
2522#ifdef CONFIG_TEST_VMALLOC_MODULE
2523EXPORT_SYMBOL_GPL(__vmalloc_node_range);
2524#endif
2525
2526/**
2527 * __vmalloc_node - allocate virtually contiguous memory
2528 * @size: allocation size
2529 * @align: desired alignment
2530 * @gfp_mask: flags for the page level allocator
2531 * @prot: protection mask for the allocated pages
2532 * @node: node to use for allocation or NUMA_NO_NODE
2533 * @caller: caller's return address
2534 *
2535 * Allocate enough pages to cover @size from the page level
2536 * allocator with @gfp_mask flags. Map them into contiguous
2537 * kernel virtual space, using a pagetable protection of @prot.
2538 *
2539 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
2540 * and __GFP_NOFAIL are not supported
2541 *
2542 * Any use of gfp flags outside of GFP_KERNEL should be consulted
2543 * with mm people.
2544 *
2545 * Return: pointer to the allocated memory or %NULL on error
2546 */
2547static void *__vmalloc_node(unsigned long size, unsigned long align,
2548 gfp_t gfp_mask, pgprot_t prot,
2549 int node, const void *caller)
2550{
2551 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
2552 gfp_mask, prot, 0, node, caller);
2553}
2554
2555void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
2556{
2557 return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
2558 __builtin_return_address(0));
2559}
2560EXPORT_SYMBOL(__vmalloc);
2561
2562static inline void *__vmalloc_node_flags(unsigned long size,
2563 int node, gfp_t flags)
2564{
2565 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
2566 node, __builtin_return_address(0));
2567}
2568
2569
2570void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags,
2571 void *caller)
2572{
2573 return __vmalloc_node(size, 1, flags, PAGE_KERNEL, node, caller);
2574}
2575
2576/**
2577 * vmalloc - allocate virtually contiguous memory
2578 * @size: allocation size
2579 *
2580 * Allocate enough pages to cover @size from the page level
2581 * allocator and map them into contiguous kernel virtual space.
2582 *
2583 * For tight control over page level allocator and protection flags
2584 * use __vmalloc() instead.
2585 *
2586 * Return: pointer to the allocated memory or %NULL on error
2587 */
2588void *vmalloc(unsigned long size)
2589{
2590 return __vmalloc_node_flags(size, NUMA_NO_NODE,
2591 GFP_KERNEL);
2592}
2593EXPORT_SYMBOL(vmalloc);
2594
2595/**
2596 * vzalloc - allocate virtually contiguous memory with zero fill
2597 * @size: allocation size
2598 *
2599 * Allocate enough pages to cover @size from the page level
2600 * allocator and map them into contiguous kernel virtual space.
2601 * The memory allocated is set to zero.
2602 *
2603 * For tight control over page level allocator and protection flags
2604 * use __vmalloc() instead.
2605 *
2606 * Return: pointer to the allocated memory or %NULL on error
2607 */
2608void *vzalloc(unsigned long size)
2609{
2610 return __vmalloc_node_flags(size, NUMA_NO_NODE,
2611 GFP_KERNEL | __GFP_ZERO);
2612}
2613EXPORT_SYMBOL(vzalloc);
2614
2615/**
2616 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
2617 * @size: allocation size
2618 *
2619 * The resulting memory area is zeroed so it can be mapped to userspace
2620 * without leaking data.
2621 *
2622 * Return: pointer to the allocated memory or %NULL on error
2623 */
2624void *vmalloc_user(unsigned long size)
2625{
2626 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
2627 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
2628 VM_USERMAP, NUMA_NO_NODE,
2629 __builtin_return_address(0));
2630}
2631EXPORT_SYMBOL(vmalloc_user);
2632
2633/**
2634 * vmalloc_node - allocate memory on a specific node
2635 * @size: allocation size
2636 * @node: numa node
2637 *
2638 * Allocate enough pages to cover @size from the page level
2639 * allocator and map them into contiguous kernel virtual space.
2640 *
2641 * For tight control over page level allocator and protection flags
2642 * use __vmalloc() instead.
2643 *
2644 * Return: pointer to the allocated memory or %NULL on error
2645 */
2646void *vmalloc_node(unsigned long size, int node)
2647{
2648 return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL,
2649 node, __builtin_return_address(0));
2650}
2651EXPORT_SYMBOL(vmalloc_node);
2652
2653/**
2654 * vzalloc_node - allocate memory on a specific node with zero fill
2655 * @size: allocation size
2656 * @node: numa node
2657 *
2658 * Allocate enough pages to cover @size from the page level
2659 * allocator and map them into contiguous kernel virtual space.
2660 * The memory allocated is set to zero.
2661 *
2662 * For tight control over page level allocator and protection flags
2663 * use __vmalloc_node() instead.
2664 *
2665 * Return: pointer to the allocated memory or %NULL on error
2666 */
2667void *vzalloc_node(unsigned long size, int node)
2668{
2669 return __vmalloc_node_flags(size, node,
2670 GFP_KERNEL | __GFP_ZERO);
2671}
2672EXPORT_SYMBOL(vzalloc_node);
2673
2674/**
2675 * vmalloc_exec - allocate virtually contiguous, executable memory
2676 * @size: allocation size
2677 *
2678 * Kernel-internal function to allocate enough pages to cover @size
2679 * the page level allocator and map them into contiguous and
2680 * executable kernel virtual space.
2681 *
2682 * For tight control over page level allocator and protection flags
2683 * use __vmalloc() instead.
2684 *
2685 * Return: pointer to the allocated memory or %NULL on error
2686 */
2687void *vmalloc_exec(unsigned long size)
2688{
2689 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
2690 GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
2691 NUMA_NO_NODE, __builtin_return_address(0));
2692}
2693
2694#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
2695#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
2696#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
2697#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
2698#else
2699/*
2700 * 64b systems should always have either DMA or DMA32 zones. For others
2701 * GFP_DMA32 should do the right thing and use the normal zone.
2702 */
2703#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
2704#endif
2705
2706/**
2707 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
2708 * @size: allocation size
2709 *
2710 * Allocate enough 32bit PA addressable pages to cover @size from the
2711 * page level allocator and map them into contiguous kernel virtual space.
2712 *
2713 * Return: pointer to the allocated memory or %NULL on error
2714 */
2715void *vmalloc_32(unsigned long size)
2716{
2717 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
2718 NUMA_NO_NODE, __builtin_return_address(0));
2719}
2720EXPORT_SYMBOL(vmalloc_32);
2721
2722/**
2723 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
2724 * @size: allocation size
2725 *
2726 * The resulting memory area is 32bit addressable and zeroed so it can be
2727 * mapped to userspace without leaking data.
2728 *
2729 * Return: pointer to the allocated memory or %NULL on error
2730 */
2731void *vmalloc_32_user(unsigned long size)
2732{
2733 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
2734 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
2735 VM_USERMAP, NUMA_NO_NODE,
2736 __builtin_return_address(0));
2737}
2738EXPORT_SYMBOL(vmalloc_32_user);
2739
2740/*
2741 * small helper routine , copy contents to buf from addr.
2742 * If the page is not present, fill zero.
2743 */
2744
2745static int aligned_vread(char *buf, char *addr, unsigned long count)
2746{
2747 struct page *p;
2748 int copied = 0;
2749
2750 while (count) {
2751 unsigned long offset, length;
2752
2753 offset = offset_in_page(addr);
2754 length = PAGE_SIZE - offset;
2755 if (length > count)
2756 length = count;
2757 p = vmalloc_to_page(addr);
2758 /*
2759 * To do safe access to this _mapped_ area, we need
2760 * lock. But adding lock here means that we need to add
2761 * overhead of vmalloc()/vfree() calles for this _debug_
2762 * interface, rarely used. Instead of that, we'll use
2763 * kmap() and get small overhead in this access function.
2764 */
2765 if (p) {
2766 /*
2767 * we can expect USER0 is not used (see vread/vwrite's
2768 * function description)
2769 */
2770 void *map = kmap_atomic(p);
2771 memcpy(buf, map + offset, length);
2772 kunmap_atomic(map);
2773 } else
2774 memset(buf, 0, length);
2775
2776 addr += length;
2777 buf += length;
2778 copied += length;
2779 count -= length;
2780 }
2781 return copied;
2782}
2783
2784static int aligned_vwrite(char *buf, char *addr, unsigned long count)
2785{
2786 struct page *p;
2787 int copied = 0;
2788
2789 while (count) {
2790 unsigned long offset, length;
2791
2792 offset = offset_in_page(addr);
2793 length = PAGE_SIZE - offset;
2794 if (length > count)
2795 length = count;
2796 p = vmalloc_to_page(addr);
2797 /*
2798 * To do safe access to this _mapped_ area, we need
2799 * lock. But adding lock here means that we need to add
2800 * overhead of vmalloc()/vfree() calles for this _debug_
2801 * interface, rarely used. Instead of that, we'll use
2802 * kmap() and get small overhead in this access function.
2803 */
2804 if (p) {
2805 /*
2806 * we can expect USER0 is not used (see vread/vwrite's
2807 * function description)
2808 */
2809 void *map = kmap_atomic(p);
2810 memcpy(map + offset, buf, length);
2811 kunmap_atomic(map);
2812 }
2813 addr += length;
2814 buf += length;
2815 copied += length;
2816 count -= length;
2817 }
2818 return copied;
2819}
2820
2821/**
2822 * vread() - read vmalloc area in a safe way.
2823 * @buf: buffer for reading data
2824 * @addr: vm address.
2825 * @count: number of bytes to be read.
2826 *
2827 * This function checks that addr is a valid vmalloc'ed area, and
2828 * copy data from that area to a given buffer. If the given memory range
2829 * of [addr...addr+count) includes some valid address, data is copied to
2830 * proper area of @buf. If there are memory holes, they'll be zero-filled.
2831 * IOREMAP area is treated as memory hole and no copy is done.
2832 *
2833 * If [addr...addr+count) doesn't includes any intersects with alive
2834 * vm_struct area, returns 0. @buf should be kernel's buffer.
2835 *
2836 * Note: In usual ops, vread() is never necessary because the caller
2837 * should know vmalloc() area is valid and can use memcpy().
2838 * This is for routines which have to access vmalloc area without
2839 * any information, as /dev/kmem.
2840 *
2841 * Return: number of bytes for which addr and buf should be increased
2842 * (same number as @count) or %0 if [addr...addr+count) doesn't
2843 * include any intersection with valid vmalloc area
2844 */
2845long vread(char *buf, char *addr, unsigned long count)
2846{
2847 struct vmap_area *va;
2848 struct vm_struct *vm;
2849 char *vaddr, *buf_start = buf;
2850 unsigned long buflen = count;
2851 unsigned long n;
2852
2853 /* Don't allow overflow */
2854 if ((unsigned long) addr + count < count)
2855 count = -(unsigned long) addr;
2856
2857 spin_lock(&vmap_area_lock);
2858 list_for_each_entry(va, &vmap_area_list, list) {
2859 if (!count)
2860 break;
2861
2862 if (!va->vm)
2863 continue;
2864
2865 vm = va->vm;
2866 vaddr = (char *) vm->addr;
2867 if (addr >= vaddr + get_vm_area_size(vm))
2868 continue;
2869 while (addr < vaddr) {
2870 if (count == 0)
2871 goto finished;
2872 *buf = '\0';
2873 buf++;
2874 addr++;
2875 count--;
2876 }
2877 n = vaddr + get_vm_area_size(vm) - addr;
2878 if (n > count)
2879 n = count;
2880 if (!(vm->flags & VM_IOREMAP))
2881 aligned_vread(buf, addr, n);
2882 else /* IOREMAP area is treated as memory hole */
2883 memset(buf, 0, n);
2884 buf += n;
2885 addr += n;
2886 count -= n;
2887 }
2888finished:
2889 spin_unlock(&vmap_area_lock);
2890
2891 if (buf == buf_start)
2892 return 0;
2893 /* zero-fill memory holes */
2894 if (buf != buf_start + buflen)
2895 memset(buf, 0, buflen - (buf - buf_start));
2896
2897 return buflen;
2898}
2899
2900/**
2901 * vwrite() - write vmalloc area in a safe way.
2902 * @buf: buffer for source data
2903 * @addr: vm address.
2904 * @count: number of bytes to be read.
2905 *
2906 * This function checks that addr is a valid vmalloc'ed area, and
2907 * copy data from a buffer to the given addr. If specified range of
2908 * [addr...addr+count) includes some valid address, data is copied from
2909 * proper area of @buf. If there are memory holes, no copy to hole.
2910 * IOREMAP area is treated as memory hole and no copy is done.
2911 *
2912 * If [addr...addr+count) doesn't includes any intersects with alive
2913 * vm_struct area, returns 0. @buf should be kernel's buffer.
2914 *
2915 * Note: In usual ops, vwrite() is never necessary because the caller
2916 * should know vmalloc() area is valid and can use memcpy().
2917 * This is for routines which have to access vmalloc area without
2918 * any information, as /dev/kmem.
2919 *
2920 * Return: number of bytes for which addr and buf should be
2921 * increased (same number as @count) or %0 if [addr...addr+count)
2922 * doesn't include any intersection with valid vmalloc area
2923 */
2924long vwrite(char *buf, char *addr, unsigned long count)
2925{
2926 struct vmap_area *va;
2927 struct vm_struct *vm;
2928 char *vaddr;
2929 unsigned long n, buflen;
2930 int copied = 0;
2931
2932 /* Don't allow overflow */
2933 if ((unsigned long) addr + count < count)
2934 count = -(unsigned long) addr;
2935 buflen = count;
2936
2937 spin_lock(&vmap_area_lock);
2938 list_for_each_entry(va, &vmap_area_list, list) {
2939 if (!count)
2940 break;
2941
2942 if (!va->vm)
2943 continue;
2944
2945 vm = va->vm;
2946 vaddr = (char *) vm->addr;
2947 if (addr >= vaddr + get_vm_area_size(vm))
2948 continue;
2949 while (addr < vaddr) {
2950 if (count == 0)
2951 goto finished;
2952 buf++;
2953 addr++;
2954 count--;
2955 }
2956 n = vaddr + get_vm_area_size(vm) - addr;
2957 if (n > count)
2958 n = count;
2959 if (!(vm->flags & VM_IOREMAP)) {
2960 aligned_vwrite(buf, addr, n);
2961 copied++;
2962 }
2963 buf += n;
2964 addr += n;
2965 count -= n;
2966 }
2967finished:
2968 spin_unlock(&vmap_area_lock);
2969 if (!copied)
2970 return 0;
2971 return buflen;
2972}
2973
2974/**
2975 * remap_vmalloc_range_partial - map vmalloc pages to userspace
2976 * @vma: vma to cover
2977 * @uaddr: target user address to start at
2978 * @kaddr: virtual address of vmalloc kernel memory
2979 * @size: size of map area
2980 *
2981 * Returns: 0 for success, -Exxx on failure
2982 *
2983 * This function checks that @kaddr is a valid vmalloc'ed area,
2984 * and that it is big enough to cover the range starting at
2985 * @uaddr in @vma. Will return failure if that criteria isn't
2986 * met.
2987 *
2988 * Similar to remap_pfn_range() (see mm/memory.c)
2989 */
2990int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
2991 void *kaddr, unsigned long size)
2992{
2993 struct vm_struct *area;
2994
2995 size = PAGE_ALIGN(size);
2996
2997 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2998 return -EINVAL;
2999
3000 area = find_vm_area(kaddr);
3001 if (!area)
3002 return -EINVAL;
3003
3004 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
3005 return -EINVAL;
3006
3007 if (kaddr + size > area->addr + get_vm_area_size(area))
3008 return -EINVAL;
3009
3010 do {
3011 struct page *page = vmalloc_to_page(kaddr);
3012 int ret;
3013
3014 ret = vm_insert_page(vma, uaddr, page);
3015 if (ret)
3016 return ret;
3017
3018 uaddr += PAGE_SIZE;
3019 kaddr += PAGE_SIZE;
3020 size -= PAGE_SIZE;
3021 } while (size > 0);
3022
3023 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
3024
3025 return 0;
3026}
3027EXPORT_SYMBOL(remap_vmalloc_range_partial);
3028
3029/**
3030 * remap_vmalloc_range - map vmalloc pages to userspace
3031 * @vma: vma to cover (map full range of vma)
3032 * @addr: vmalloc memory
3033 * @pgoff: number of pages into addr before first page to map
3034 *
3035 * Returns: 0 for success, -Exxx on failure
3036 *
3037 * This function checks that addr is a valid vmalloc'ed area, and
3038 * that it is big enough to cover the vma. Will return failure if
3039 * that criteria isn't met.
3040 *
3041 * Similar to remap_pfn_range() (see mm/memory.c)
3042 */
3043int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
3044 unsigned long pgoff)
3045{
3046 return remap_vmalloc_range_partial(vma, vma->vm_start,
3047 addr + (pgoff << PAGE_SHIFT),
3048 vma->vm_end - vma->vm_start);
3049}
3050EXPORT_SYMBOL(remap_vmalloc_range);
3051
3052/*
3053 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
3054 * have one.
3055 *
3056 * The purpose of this function is to make sure the vmalloc area
3057 * mappings are identical in all page-tables in the system.
3058 */
3059void __weak vmalloc_sync_all(void)
3060{
3061}
3062
3063
3064static int f(pte_t *pte, unsigned long addr, void *data)
3065{
3066 pte_t ***p = data;
3067
3068 if (p) {
3069 *(*p) = pte;
3070 (*p)++;
3071 }
3072 return 0;
3073}
3074
3075/**
3076 * alloc_vm_area - allocate a range of kernel address space
3077 * @size: size of the area
3078 * @ptes: returns the PTEs for the address space
3079 *
3080 * Returns: NULL on failure, vm_struct on success
3081 *
3082 * This function reserves a range of kernel address space, and
3083 * allocates pagetables to map that range. No actual mappings
3084 * are created.
3085 *
3086 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
3087 * allocated for the VM area are returned.
3088 */
3089struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
3090{
3091 struct vm_struct *area;
3092
3093 area = get_vm_area_caller(size, VM_IOREMAP,
3094 __builtin_return_address(0));
3095 if (area == NULL)
3096 return NULL;
3097
3098 /*
3099 * This ensures that page tables are constructed for this region
3100 * of kernel virtual address space and mapped into init_mm.
3101 */
3102 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
3103 size, f, ptes ? &ptes : NULL)) {
3104 free_vm_area(area);
3105 return NULL;
3106 }
3107
3108 return area;
3109}
3110EXPORT_SYMBOL_GPL(alloc_vm_area);
3111
3112void free_vm_area(struct vm_struct *area)
3113{
3114 struct vm_struct *ret;
3115 ret = remove_vm_area(area->addr);
3116 BUG_ON(ret != area);
3117 kfree(area);
3118}
3119EXPORT_SYMBOL_GPL(free_vm_area);
3120
3121#ifdef CONFIG_SMP
3122static struct vmap_area *node_to_va(struct rb_node *n)
3123{
3124 return rb_entry_safe(n, struct vmap_area, rb_node);
3125}
3126
3127/**
3128 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
3129 * @addr: target address
3130 *
3131 * Returns: vmap_area if it is found. If there is no such area
3132 * the first highest(reverse order) vmap_area is returned
3133 * i.e. va->va_start < addr && va->va_end < addr or NULL
3134 * if there are no any areas before @addr.
3135 */
3136static struct vmap_area *
3137pvm_find_va_enclose_addr(unsigned long addr)
3138{
3139 struct vmap_area *va, *tmp;
3140 struct rb_node *n;
3141
3142 n = free_vmap_area_root.rb_node;
3143 va = NULL;
3144
3145 while (n) {
3146 tmp = rb_entry(n, struct vmap_area, rb_node);
3147 if (tmp->va_start <= addr) {
3148 va = tmp;
3149 if (tmp->va_end >= addr)
3150 break;
3151
3152 n = n->rb_right;
3153 } else {
3154 n = n->rb_left;
3155 }
3156 }
3157
3158 return va;
3159}
3160
3161/**
3162 * pvm_determine_end_from_reverse - find the highest aligned address
3163 * of free block below VMALLOC_END
3164 * @va:
3165 * in - the VA we start the search(reverse order);
3166 * out - the VA with the highest aligned end address.
3167 *
3168 * Returns: determined end address within vmap_area
3169 */
3170static unsigned long
3171pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
3172{
3173 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3174 unsigned long addr;
3175
3176 if (likely(*va)) {
3177 list_for_each_entry_from_reverse((*va),
3178 &free_vmap_area_list, list) {
3179 addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
3180 if ((*va)->va_start < addr)
3181 return addr;
3182 }
3183 }
3184
3185 return 0;
3186}
3187
3188/**
3189 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
3190 * @offsets: array containing offset of each area
3191 * @sizes: array containing size of each area
3192 * @nr_vms: the number of areas to allocate
3193 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
3194 *
3195 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
3196 * vm_structs on success, %NULL on failure
3197 *
3198 * Percpu allocator wants to use congruent vm areas so that it can
3199 * maintain the offsets among percpu areas. This function allocates
3200 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
3201 * be scattered pretty far, distance between two areas easily going up
3202 * to gigabytes. To avoid interacting with regular vmallocs, these
3203 * areas are allocated from top.
3204 *
3205 * Despite its complicated look, this allocator is rather simple. It
3206 * does everything top-down and scans free blocks from the end looking
3207 * for matching base. While scanning, if any of the areas do not fit the
3208 * base address is pulled down to fit the area. Scanning is repeated till
3209 * all the areas fit and then all necessary data structures are inserted
3210 * and the result is returned.
3211 */
3212struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
3213 const size_t *sizes, int nr_vms,
3214 size_t align)
3215{
3216 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
3217 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3218 struct vmap_area **vas, *va;
3219 struct vm_struct **vms;
3220 int area, area2, last_area, term_area;
3221 unsigned long base, start, size, end, last_end;
3222 bool purged = false;
3223 enum fit_type type;
3224
3225 /* verify parameters and allocate data structures */
3226 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
3227 for (last_area = 0, area = 0; area < nr_vms; area++) {
3228 start = offsets[area];
3229 end = start + sizes[area];
3230
3231 /* is everything aligned properly? */
3232 BUG_ON(!IS_ALIGNED(offsets[area], align));
3233 BUG_ON(!IS_ALIGNED(sizes[area], align));
3234
3235 /* detect the area with the highest address */
3236 if (start > offsets[last_area])
3237 last_area = area;
3238
3239 for (area2 = area + 1; area2 < nr_vms; area2++) {
3240 unsigned long start2 = offsets[area2];
3241 unsigned long end2 = start2 + sizes[area2];
3242
3243 BUG_ON(start2 < end && start < end2);
3244 }
3245 }
3246 last_end = offsets[last_area] + sizes[last_area];
3247
3248 if (vmalloc_end - vmalloc_start < last_end) {
3249 WARN_ON(true);
3250 return NULL;
3251 }
3252
3253 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
3254 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
3255 if (!vas || !vms)
3256 goto err_free2;
3257
3258 for (area = 0; area < nr_vms; area++) {
3259 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
3260 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
3261 if (!vas[area] || !vms[area])
3262 goto err_free;
3263 }
3264retry:
3265 spin_lock(&vmap_area_lock);
3266
3267 /* start scanning - we scan from the top, begin with the last area */
3268 area = term_area = last_area;
3269 start = offsets[area];
3270 end = start + sizes[area];
3271
3272 va = pvm_find_va_enclose_addr(vmalloc_end);
3273 base = pvm_determine_end_from_reverse(&va, align) - end;
3274
3275 while (true) {
3276 /*
3277 * base might have underflowed, add last_end before
3278 * comparing.
3279 */
3280 if (base + last_end < vmalloc_start + last_end)
3281 goto overflow;
3282
3283 /*
3284 * Fitting base has not been found.
3285 */
3286 if (va == NULL)
3287 goto overflow;
3288
3289 /*
3290 * If required width exeeds current VA block, move
3291 * base downwards and then recheck.
3292 */
3293 if (base + end > va->va_end) {
3294 base = pvm_determine_end_from_reverse(&va, align) - end;
3295 term_area = area;
3296 continue;
3297 }
3298
3299 /*
3300 * If this VA does not fit, move base downwards and recheck.
3301 */
3302 if (base + start < va->va_start) {
3303 va = node_to_va(rb_prev(&va->rb_node));
3304 base = pvm_determine_end_from_reverse(&va, align) - end;
3305 term_area = area;
3306 continue;
3307 }
3308
3309 /*
3310 * This area fits, move on to the previous one. If
3311 * the previous one is the terminal one, we're done.
3312 */
3313 area = (area + nr_vms - 1) % nr_vms;
3314 if (area == term_area)
3315 break;
3316
3317 start = offsets[area];
3318 end = start + sizes[area];
3319 va = pvm_find_va_enclose_addr(base + end);
3320 }
3321
3322 /* we've found a fitting base, insert all va's */
3323 for (area = 0; area < nr_vms; area++) {
3324 int ret;
3325
3326 start = base + offsets[area];
3327 size = sizes[area];
3328
3329 va = pvm_find_va_enclose_addr(start);
3330 if (WARN_ON_ONCE(va == NULL))
3331 /* It is a BUG(), but trigger recovery instead. */
3332 goto recovery;
3333
3334 type = classify_va_fit_type(va, start, size);
3335 if (WARN_ON_ONCE(type == NOTHING_FIT))
3336 /* It is a BUG(), but trigger recovery instead. */
3337 goto recovery;
3338
3339 ret = adjust_va_to_fit_type(va, start, size, type);
3340 if (unlikely(ret))
3341 goto recovery;
3342
3343 /* Allocated area. */
3344 va = vas[area];
3345 va->va_start = start;
3346 va->va_end = start + size;
3347
3348 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
3349 }
3350
3351 spin_unlock(&vmap_area_lock);
3352
3353 /* insert all vm's */
3354 for (area = 0; area < nr_vms; area++)
3355 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
3356 pcpu_get_vm_areas);
3357
3358 kfree(vas);
3359 return vms;
3360
3361recovery:
3362 /* Remove previously inserted areas. */
3363 while (area--) {
3364 __free_vmap_area(vas[area]);
3365 vas[area] = NULL;
3366 }
3367
3368overflow:
3369 spin_unlock(&vmap_area_lock);
3370 if (!purged) {
3371 purge_vmap_area_lazy();
3372 purged = true;
3373
3374 /* Before "retry", check if we recover. */
3375 for (area = 0; area < nr_vms; area++) {
3376 if (vas[area])
3377 continue;
3378
3379 vas[area] = kmem_cache_zalloc(
3380 vmap_area_cachep, GFP_KERNEL);
3381 if (!vas[area])
3382 goto err_free;
3383 }
3384
3385 goto retry;
3386 }
3387
3388err_free:
3389 for (area = 0; area < nr_vms; area++) {
3390 if (vas[area])
3391 kmem_cache_free(vmap_area_cachep, vas[area]);
3392
3393 kfree(vms[area]);
3394 }
3395err_free2:
3396 kfree(vas);
3397 kfree(vms);
3398 return NULL;
3399}
3400
3401/**
3402 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
3403 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
3404 * @nr_vms: the number of allocated areas
3405 *
3406 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
3407 */
3408void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
3409{
3410 int i;
3411
3412 for (i = 0; i < nr_vms; i++)
3413 free_vm_area(vms[i]);
3414 kfree(vms);
3415}
3416#endif /* CONFIG_SMP */
3417
3418#ifdef CONFIG_PROC_FS
3419static void *s_start(struct seq_file *m, loff_t *pos)
3420 __acquires(&vmap_area_lock)
3421{
3422 spin_lock(&vmap_area_lock);
3423 return seq_list_start(&vmap_area_list, *pos);
3424}
3425
3426static void *s_next(struct seq_file *m, void *p, loff_t *pos)
3427{
3428 return seq_list_next(p, &vmap_area_list, pos);
3429}
3430
3431static void s_stop(struct seq_file *m, void *p)
3432 __releases(&vmap_area_lock)
3433{
3434 spin_unlock(&vmap_area_lock);
3435}
3436
3437static void show_numa_info(struct seq_file *m, struct vm_struct *v)
3438{
3439 if (IS_ENABLED(CONFIG_NUMA)) {
3440 unsigned int nr, *counters = m->private;
3441
3442 if (!counters)
3443 return;
3444
3445 if (v->flags & VM_UNINITIALIZED)
3446 return;
3447 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
3448 smp_rmb();
3449
3450 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
3451
3452 for (nr = 0; nr < v->nr_pages; nr++)
3453 counters[page_to_nid(v->pages[nr])]++;
3454
3455 for_each_node_state(nr, N_HIGH_MEMORY)
3456 if (counters[nr])
3457 seq_printf(m, " N%u=%u", nr, counters[nr]);
3458 }
3459}
3460
3461static void show_purge_info(struct seq_file *m)
3462{
3463 struct llist_node *head;
3464 struct vmap_area *va;
3465
3466 head = READ_ONCE(vmap_purge_list.first);
3467 if (head == NULL)
3468 return;
3469
3470 llist_for_each_entry(va, head, purge_list) {
3471 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
3472 (void *)va->va_start, (void *)va->va_end,
3473 va->va_end - va->va_start);
3474 }
3475}
3476
3477static int s_show(struct seq_file *m, void *p)
3478{
3479 struct vmap_area *va;
3480 struct vm_struct *v;
3481
3482 va = list_entry(p, struct vmap_area, list);
3483
3484 /*
3485 * s_show can encounter race with remove_vm_area, !vm on behalf
3486 * of vmap area is being tear down or vm_map_ram allocation.
3487 */
3488 if (!va->vm) {
3489 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
3490 (void *)va->va_start, (void *)va->va_end,
3491 va->va_end - va->va_start);
3492
3493 return 0;
3494 }
3495
3496 v = va->vm;
3497
3498 seq_printf(m, "0x%pK-0x%pK %7ld",
3499 v->addr, v->addr + v->size, v->size);
3500
3501 if (v->caller)
3502 seq_printf(m, " %pS", v->caller);
3503
3504 if (v->nr_pages)
3505 seq_printf(m, " pages=%d", v->nr_pages);
3506
3507 if (v->phys_addr)
3508 seq_printf(m, " phys=%pa", &v->phys_addr);
3509
3510 if (v->flags & VM_IOREMAP)
3511 seq_puts(m, " ioremap");
3512
3513 if (v->flags & VM_ALLOC)
3514 seq_puts(m, " vmalloc");
3515
3516 if (v->flags & VM_MAP)
3517 seq_puts(m, " vmap");
3518
3519 if (v->flags & VM_USERMAP)
3520 seq_puts(m, " user");
3521
3522 if (v->flags & VM_DMA_COHERENT)
3523 seq_puts(m, " dma-coherent");
3524
3525 if (is_vmalloc_addr(v->pages))
3526 seq_puts(m, " vpages");
3527
3528 show_numa_info(m, v);
3529 seq_putc(m, '\n');
3530
3531 /*
3532 * As a final step, dump "unpurged" areas. Note,
3533 * that entire "/proc/vmallocinfo" output will not
3534 * be address sorted, because the purge list is not
3535 * sorted.
3536 */
3537 if (list_is_last(&va->list, &vmap_area_list))
3538 show_purge_info(m);
3539
3540 return 0;
3541}
3542
3543static const struct seq_operations vmalloc_op = {
3544 .start = s_start,
3545 .next = s_next,
3546 .stop = s_stop,
3547 .show = s_show,
3548};
3549
3550static int __init proc_vmalloc_init(void)
3551{
3552 if (IS_ENABLED(CONFIG_NUMA))
3553 proc_create_seq_private("vmallocinfo", 0400, NULL,
3554 &vmalloc_op,
3555 nr_node_ids * sizeof(unsigned int), NULL);
3556 else
3557 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
3558 return 0;
3559}
3560module_init(proc_vmalloc_init);
3561
3562#endif
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 1993 Linus Torvalds
4 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
5 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
6 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
7 * Numa awareness, Christoph Lameter, SGI, June 2005
8 * Improving global KVA allocator, Uladzislau Rezki, Sony, May 2019
9 */
10
11#include <linux/vmalloc.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/highmem.h>
15#include <linux/sched/signal.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/set_memory.h>
22#include <linux/debugobjects.h>
23#include <linux/kallsyms.h>
24#include <linux/list.h>
25#include <linux/notifier.h>
26#include <linux/rbtree.h>
27#include <linux/xarray.h>
28#include <linux/io.h>
29#include <linux/rcupdate.h>
30#include <linux/pfn.h>
31#include <linux/kmemleak.h>
32#include <linux/atomic.h>
33#include <linux/compiler.h>
34#include <linux/memcontrol.h>
35#include <linux/llist.h>
36#include <linux/uio.h>
37#include <linux/bitops.h>
38#include <linux/rbtree_augmented.h>
39#include <linux/overflow.h>
40#include <linux/pgtable.h>
41#include <linux/hugetlb.h>
42#include <linux/sched/mm.h>
43#include <asm/tlbflush.h>
44#include <asm/shmparam.h>
45#include <linux/page_owner.h>
46
47#define CREATE_TRACE_POINTS
48#include <trace/events/vmalloc.h>
49
50#include "internal.h"
51#include "pgalloc-track.h"
52
53#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
54static unsigned int __ro_after_init ioremap_max_page_shift = BITS_PER_LONG - 1;
55
56static int __init set_nohugeiomap(char *str)
57{
58 ioremap_max_page_shift = PAGE_SHIFT;
59 return 0;
60}
61early_param("nohugeiomap", set_nohugeiomap);
62#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
63static const unsigned int ioremap_max_page_shift = PAGE_SHIFT;
64#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
65
66#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
67static bool __ro_after_init vmap_allow_huge = true;
68
69static int __init set_nohugevmalloc(char *str)
70{
71 vmap_allow_huge = false;
72 return 0;
73}
74early_param("nohugevmalloc", set_nohugevmalloc);
75#else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
76static const bool vmap_allow_huge = false;
77#endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
78
79bool is_vmalloc_addr(const void *x)
80{
81 unsigned long addr = (unsigned long)kasan_reset_tag(x);
82
83 return addr >= VMALLOC_START && addr < VMALLOC_END;
84}
85EXPORT_SYMBOL(is_vmalloc_addr);
86
87struct vfree_deferred {
88 struct llist_head list;
89 struct work_struct wq;
90};
91static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
92
93/*** Page table manipulation functions ***/
94static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
95 phys_addr_t phys_addr, pgprot_t prot,
96 unsigned int max_page_shift, pgtbl_mod_mask *mask)
97{
98 pte_t *pte;
99 u64 pfn;
100 struct page *page;
101 unsigned long size = PAGE_SIZE;
102
103 pfn = phys_addr >> PAGE_SHIFT;
104 pte = pte_alloc_kernel_track(pmd, addr, mask);
105 if (!pte)
106 return -ENOMEM;
107 do {
108 if (unlikely(!pte_none(ptep_get(pte)))) {
109 if (pfn_valid(pfn)) {
110 page = pfn_to_page(pfn);
111 dump_page(page, "remapping already mapped page");
112 }
113 BUG();
114 }
115
116#ifdef CONFIG_HUGETLB_PAGE
117 size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
118 if (size != PAGE_SIZE) {
119 pte_t entry = pfn_pte(pfn, prot);
120
121 entry = arch_make_huge_pte(entry, ilog2(size), 0);
122 set_huge_pte_at(&init_mm, addr, pte, entry, size);
123 pfn += PFN_DOWN(size);
124 continue;
125 }
126#endif
127 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
128 pfn++;
129 } while (pte += PFN_DOWN(size), addr += size, addr != end);
130 *mask |= PGTBL_PTE_MODIFIED;
131 return 0;
132}
133
134static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
135 phys_addr_t phys_addr, pgprot_t prot,
136 unsigned int max_page_shift)
137{
138 if (max_page_shift < PMD_SHIFT)
139 return 0;
140
141 if (!arch_vmap_pmd_supported(prot))
142 return 0;
143
144 if ((end - addr) != PMD_SIZE)
145 return 0;
146
147 if (!IS_ALIGNED(addr, PMD_SIZE))
148 return 0;
149
150 if (!IS_ALIGNED(phys_addr, PMD_SIZE))
151 return 0;
152
153 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
154 return 0;
155
156 return pmd_set_huge(pmd, phys_addr, prot);
157}
158
159static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
160 phys_addr_t phys_addr, pgprot_t prot,
161 unsigned int max_page_shift, pgtbl_mod_mask *mask)
162{
163 pmd_t *pmd;
164 unsigned long next;
165
166 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
167 if (!pmd)
168 return -ENOMEM;
169 do {
170 next = pmd_addr_end(addr, end);
171
172 if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot,
173 max_page_shift)) {
174 *mask |= PGTBL_PMD_MODIFIED;
175 continue;
176 }
177
178 if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask))
179 return -ENOMEM;
180 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
181 return 0;
182}
183
184static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
185 phys_addr_t phys_addr, pgprot_t prot,
186 unsigned int max_page_shift)
187{
188 if (max_page_shift < PUD_SHIFT)
189 return 0;
190
191 if (!arch_vmap_pud_supported(prot))
192 return 0;
193
194 if ((end - addr) != PUD_SIZE)
195 return 0;
196
197 if (!IS_ALIGNED(addr, PUD_SIZE))
198 return 0;
199
200 if (!IS_ALIGNED(phys_addr, PUD_SIZE))
201 return 0;
202
203 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
204 return 0;
205
206 return pud_set_huge(pud, phys_addr, prot);
207}
208
209static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
210 phys_addr_t phys_addr, pgprot_t prot,
211 unsigned int max_page_shift, pgtbl_mod_mask *mask)
212{
213 pud_t *pud;
214 unsigned long next;
215
216 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
217 if (!pud)
218 return -ENOMEM;
219 do {
220 next = pud_addr_end(addr, end);
221
222 if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot,
223 max_page_shift)) {
224 *mask |= PGTBL_PUD_MODIFIED;
225 continue;
226 }
227
228 if (vmap_pmd_range(pud, addr, next, phys_addr, prot,
229 max_page_shift, mask))
230 return -ENOMEM;
231 } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
232 return 0;
233}
234
235static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
236 phys_addr_t phys_addr, pgprot_t prot,
237 unsigned int max_page_shift)
238{
239 if (max_page_shift < P4D_SHIFT)
240 return 0;
241
242 if (!arch_vmap_p4d_supported(prot))
243 return 0;
244
245 if ((end - addr) != P4D_SIZE)
246 return 0;
247
248 if (!IS_ALIGNED(addr, P4D_SIZE))
249 return 0;
250
251 if (!IS_ALIGNED(phys_addr, P4D_SIZE))
252 return 0;
253
254 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
255 return 0;
256
257 return p4d_set_huge(p4d, phys_addr, prot);
258}
259
260static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
261 phys_addr_t phys_addr, pgprot_t prot,
262 unsigned int max_page_shift, pgtbl_mod_mask *mask)
263{
264 p4d_t *p4d;
265 unsigned long next;
266
267 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
268 if (!p4d)
269 return -ENOMEM;
270 do {
271 next = p4d_addr_end(addr, end);
272
273 if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot,
274 max_page_shift)) {
275 *mask |= PGTBL_P4D_MODIFIED;
276 continue;
277 }
278
279 if (vmap_pud_range(p4d, addr, next, phys_addr, prot,
280 max_page_shift, mask))
281 return -ENOMEM;
282 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
283 return 0;
284}
285
286static int vmap_range_noflush(unsigned long addr, unsigned long end,
287 phys_addr_t phys_addr, pgprot_t prot,
288 unsigned int max_page_shift)
289{
290 pgd_t *pgd;
291 unsigned long start;
292 unsigned long next;
293 int err;
294 pgtbl_mod_mask mask = 0;
295
296 might_sleep();
297 BUG_ON(addr >= end);
298
299 start = addr;
300 pgd = pgd_offset_k(addr);
301 do {
302 next = pgd_addr_end(addr, end);
303 err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
304 max_page_shift, &mask);
305 if (err)
306 break;
307 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
308
309 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
310 arch_sync_kernel_mappings(start, end);
311
312 return err;
313}
314
315int vmap_page_range(unsigned long addr, unsigned long end,
316 phys_addr_t phys_addr, pgprot_t prot)
317{
318 int err;
319
320 err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot),
321 ioremap_max_page_shift);
322 flush_cache_vmap(addr, end);
323 if (!err)
324 err = kmsan_ioremap_page_range(addr, end, phys_addr, prot,
325 ioremap_max_page_shift);
326 return err;
327}
328
329int ioremap_page_range(unsigned long addr, unsigned long end,
330 phys_addr_t phys_addr, pgprot_t prot)
331{
332 struct vm_struct *area;
333
334 area = find_vm_area((void *)addr);
335 if (!area || !(area->flags & VM_IOREMAP)) {
336 WARN_ONCE(1, "vm_area at addr %lx is not marked as VM_IOREMAP\n", addr);
337 return -EINVAL;
338 }
339 if (addr != (unsigned long)area->addr ||
340 (void *)end != area->addr + get_vm_area_size(area)) {
341 WARN_ONCE(1, "ioremap request [%lx,%lx) doesn't match vm_area [%lx, %lx)\n",
342 addr, end, (long)area->addr,
343 (long)area->addr + get_vm_area_size(area));
344 return -ERANGE;
345 }
346 return vmap_page_range(addr, end, phys_addr, prot);
347}
348
349static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
350 pgtbl_mod_mask *mask)
351{
352 pte_t *pte;
353
354 pte = pte_offset_kernel(pmd, addr);
355 do {
356 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
357 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
358 } while (pte++, addr += PAGE_SIZE, addr != end);
359 *mask |= PGTBL_PTE_MODIFIED;
360}
361
362static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
363 pgtbl_mod_mask *mask)
364{
365 pmd_t *pmd;
366 unsigned long next;
367 int cleared;
368
369 pmd = pmd_offset(pud, addr);
370 do {
371 next = pmd_addr_end(addr, end);
372
373 cleared = pmd_clear_huge(pmd);
374 if (cleared || pmd_bad(*pmd))
375 *mask |= PGTBL_PMD_MODIFIED;
376
377 if (cleared)
378 continue;
379 if (pmd_none_or_clear_bad(pmd))
380 continue;
381 vunmap_pte_range(pmd, addr, next, mask);
382
383 cond_resched();
384 } while (pmd++, addr = next, addr != end);
385}
386
387static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
388 pgtbl_mod_mask *mask)
389{
390 pud_t *pud;
391 unsigned long next;
392 int cleared;
393
394 pud = pud_offset(p4d, addr);
395 do {
396 next = pud_addr_end(addr, end);
397
398 cleared = pud_clear_huge(pud);
399 if (cleared || pud_bad(*pud))
400 *mask |= PGTBL_PUD_MODIFIED;
401
402 if (cleared)
403 continue;
404 if (pud_none_or_clear_bad(pud))
405 continue;
406 vunmap_pmd_range(pud, addr, next, mask);
407 } while (pud++, addr = next, addr != end);
408}
409
410static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
411 pgtbl_mod_mask *mask)
412{
413 p4d_t *p4d;
414 unsigned long next;
415
416 p4d = p4d_offset(pgd, addr);
417 do {
418 next = p4d_addr_end(addr, end);
419
420 p4d_clear_huge(p4d);
421 if (p4d_bad(*p4d))
422 *mask |= PGTBL_P4D_MODIFIED;
423
424 if (p4d_none_or_clear_bad(p4d))
425 continue;
426 vunmap_pud_range(p4d, addr, next, mask);
427 } while (p4d++, addr = next, addr != end);
428}
429
430/*
431 * vunmap_range_noflush is similar to vunmap_range, but does not
432 * flush caches or TLBs.
433 *
434 * The caller is responsible for calling flush_cache_vmap() before calling
435 * this function, and flush_tlb_kernel_range after it has returned
436 * successfully (and before the addresses are expected to cause a page fault
437 * or be re-mapped for something else, if TLB flushes are being delayed or
438 * coalesced).
439 *
440 * This is an internal function only. Do not use outside mm/.
441 */
442void __vunmap_range_noflush(unsigned long start, unsigned long end)
443{
444 unsigned long next;
445 pgd_t *pgd;
446 unsigned long addr = start;
447 pgtbl_mod_mask mask = 0;
448
449 BUG_ON(addr >= end);
450 pgd = pgd_offset_k(addr);
451 do {
452 next = pgd_addr_end(addr, end);
453 if (pgd_bad(*pgd))
454 mask |= PGTBL_PGD_MODIFIED;
455 if (pgd_none_or_clear_bad(pgd))
456 continue;
457 vunmap_p4d_range(pgd, addr, next, &mask);
458 } while (pgd++, addr = next, addr != end);
459
460 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
461 arch_sync_kernel_mappings(start, end);
462}
463
464void vunmap_range_noflush(unsigned long start, unsigned long end)
465{
466 kmsan_vunmap_range_noflush(start, end);
467 __vunmap_range_noflush(start, end);
468}
469
470/**
471 * vunmap_range - unmap kernel virtual addresses
472 * @addr: start of the VM area to unmap
473 * @end: end of the VM area to unmap (non-inclusive)
474 *
475 * Clears any present PTEs in the virtual address range, flushes TLBs and
476 * caches. Any subsequent access to the address before it has been re-mapped
477 * is a kernel bug.
478 */
479void vunmap_range(unsigned long addr, unsigned long end)
480{
481 flush_cache_vunmap(addr, end);
482 vunmap_range_noflush(addr, end);
483 flush_tlb_kernel_range(addr, end);
484}
485
486static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
487 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
488 pgtbl_mod_mask *mask)
489{
490 pte_t *pte;
491
492 /*
493 * nr is a running index into the array which helps higher level
494 * callers keep track of where we're up to.
495 */
496
497 pte = pte_alloc_kernel_track(pmd, addr, mask);
498 if (!pte)
499 return -ENOMEM;
500 do {
501 struct page *page = pages[*nr];
502
503 if (WARN_ON(!pte_none(ptep_get(pte))))
504 return -EBUSY;
505 if (WARN_ON(!page))
506 return -ENOMEM;
507 if (WARN_ON(!pfn_valid(page_to_pfn(page))))
508 return -EINVAL;
509
510 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
511 (*nr)++;
512 } while (pte++, addr += PAGE_SIZE, addr != end);
513 *mask |= PGTBL_PTE_MODIFIED;
514 return 0;
515}
516
517static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr,
518 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
519 pgtbl_mod_mask *mask)
520{
521 pmd_t *pmd;
522 unsigned long next;
523
524 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
525 if (!pmd)
526 return -ENOMEM;
527 do {
528 next = pmd_addr_end(addr, end);
529 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask))
530 return -ENOMEM;
531 } while (pmd++, addr = next, addr != end);
532 return 0;
533}
534
535static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr,
536 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
537 pgtbl_mod_mask *mask)
538{
539 pud_t *pud;
540 unsigned long next;
541
542 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
543 if (!pud)
544 return -ENOMEM;
545 do {
546 next = pud_addr_end(addr, end);
547 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask))
548 return -ENOMEM;
549 } while (pud++, addr = next, addr != end);
550 return 0;
551}
552
553static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr,
554 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
555 pgtbl_mod_mask *mask)
556{
557 p4d_t *p4d;
558 unsigned long next;
559
560 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
561 if (!p4d)
562 return -ENOMEM;
563 do {
564 next = p4d_addr_end(addr, end);
565 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask))
566 return -ENOMEM;
567 } while (p4d++, addr = next, addr != end);
568 return 0;
569}
570
571static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
572 pgprot_t prot, struct page **pages)
573{
574 unsigned long start = addr;
575 pgd_t *pgd;
576 unsigned long next;
577 int err = 0;
578 int nr = 0;
579 pgtbl_mod_mask mask = 0;
580
581 BUG_ON(addr >= end);
582 pgd = pgd_offset_k(addr);
583 do {
584 next = pgd_addr_end(addr, end);
585 if (pgd_bad(*pgd))
586 mask |= PGTBL_PGD_MODIFIED;
587 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
588 if (err)
589 break;
590 } while (pgd++, addr = next, addr != end);
591
592 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
593 arch_sync_kernel_mappings(start, end);
594
595 return err;
596}
597
598/*
599 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
600 * flush caches.
601 *
602 * The caller is responsible for calling flush_cache_vmap() after this
603 * function returns successfully and before the addresses are accessed.
604 *
605 * This is an internal function only. Do not use outside mm/.
606 */
607int __vmap_pages_range_noflush(unsigned long addr, unsigned long end,
608 pgprot_t prot, struct page **pages, unsigned int page_shift)
609{
610 unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
611
612 WARN_ON(page_shift < PAGE_SHIFT);
613
614 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
615 page_shift == PAGE_SHIFT)
616 return vmap_small_pages_range_noflush(addr, end, prot, pages);
617
618 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
619 int err;
620
621 err = vmap_range_noflush(addr, addr + (1UL << page_shift),
622 page_to_phys(pages[i]), prot,
623 page_shift);
624 if (err)
625 return err;
626
627 addr += 1UL << page_shift;
628 }
629
630 return 0;
631}
632
633int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
634 pgprot_t prot, struct page **pages, unsigned int page_shift)
635{
636 int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages,
637 page_shift);
638
639 if (ret)
640 return ret;
641 return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
642}
643
644/**
645 * vmap_pages_range - map pages to a kernel virtual address
646 * @addr: start of the VM area to map
647 * @end: end of the VM area to map (non-inclusive)
648 * @prot: page protection flags to use
649 * @pages: pages to map (always PAGE_SIZE pages)
650 * @page_shift: maximum shift that the pages may be mapped with, @pages must
651 * be aligned and contiguous up to at least this shift.
652 *
653 * RETURNS:
654 * 0 on success, -errno on failure.
655 */
656int vmap_pages_range(unsigned long addr, unsigned long end,
657 pgprot_t prot, struct page **pages, unsigned int page_shift)
658{
659 int err;
660
661 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
662 flush_cache_vmap(addr, end);
663 return err;
664}
665
666static int check_sparse_vm_area(struct vm_struct *area, unsigned long start,
667 unsigned long end)
668{
669 might_sleep();
670 if (WARN_ON_ONCE(area->flags & VM_FLUSH_RESET_PERMS))
671 return -EINVAL;
672 if (WARN_ON_ONCE(area->flags & VM_NO_GUARD))
673 return -EINVAL;
674 if (WARN_ON_ONCE(!(area->flags & VM_SPARSE)))
675 return -EINVAL;
676 if ((end - start) >> PAGE_SHIFT > totalram_pages())
677 return -E2BIG;
678 if (start < (unsigned long)area->addr ||
679 (void *)end > area->addr + get_vm_area_size(area))
680 return -ERANGE;
681 return 0;
682}
683
684/**
685 * vm_area_map_pages - map pages inside given sparse vm_area
686 * @area: vm_area
687 * @start: start address inside vm_area
688 * @end: end address inside vm_area
689 * @pages: pages to map (always PAGE_SIZE pages)
690 */
691int vm_area_map_pages(struct vm_struct *area, unsigned long start,
692 unsigned long end, struct page **pages)
693{
694 int err;
695
696 err = check_sparse_vm_area(area, start, end);
697 if (err)
698 return err;
699
700 return vmap_pages_range(start, end, PAGE_KERNEL, pages, PAGE_SHIFT);
701}
702
703/**
704 * vm_area_unmap_pages - unmap pages inside given sparse vm_area
705 * @area: vm_area
706 * @start: start address inside vm_area
707 * @end: end address inside vm_area
708 */
709void vm_area_unmap_pages(struct vm_struct *area, unsigned long start,
710 unsigned long end)
711{
712 if (check_sparse_vm_area(area, start, end))
713 return;
714
715 vunmap_range(start, end);
716}
717
718int is_vmalloc_or_module_addr(const void *x)
719{
720 /*
721 * ARM, x86-64 and sparc64 put modules in a special place,
722 * and fall back on vmalloc() if that fails. Others
723 * just put it in the vmalloc space.
724 */
725#if defined(CONFIG_EXECMEM) && defined(MODULES_VADDR)
726 unsigned long addr = (unsigned long)kasan_reset_tag(x);
727 if (addr >= MODULES_VADDR && addr < MODULES_END)
728 return 1;
729#endif
730 return is_vmalloc_addr(x);
731}
732EXPORT_SYMBOL_GPL(is_vmalloc_or_module_addr);
733
734/*
735 * Walk a vmap address to the struct page it maps. Huge vmap mappings will
736 * return the tail page that corresponds to the base page address, which
737 * matches small vmap mappings.
738 */
739struct page *vmalloc_to_page(const void *vmalloc_addr)
740{
741 unsigned long addr = (unsigned long) vmalloc_addr;
742 struct page *page = NULL;
743 pgd_t *pgd = pgd_offset_k(addr);
744 p4d_t *p4d;
745 pud_t *pud;
746 pmd_t *pmd;
747 pte_t *ptep, pte;
748
749 /*
750 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
751 * architectures that do not vmalloc module space
752 */
753 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
754
755 if (pgd_none(*pgd))
756 return NULL;
757 if (WARN_ON_ONCE(pgd_leaf(*pgd)))
758 return NULL; /* XXX: no allowance for huge pgd */
759 if (WARN_ON_ONCE(pgd_bad(*pgd)))
760 return NULL;
761
762 p4d = p4d_offset(pgd, addr);
763 if (p4d_none(*p4d))
764 return NULL;
765 if (p4d_leaf(*p4d))
766 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
767 if (WARN_ON_ONCE(p4d_bad(*p4d)))
768 return NULL;
769
770 pud = pud_offset(p4d, addr);
771 if (pud_none(*pud))
772 return NULL;
773 if (pud_leaf(*pud))
774 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
775 if (WARN_ON_ONCE(pud_bad(*pud)))
776 return NULL;
777
778 pmd = pmd_offset(pud, addr);
779 if (pmd_none(*pmd))
780 return NULL;
781 if (pmd_leaf(*pmd))
782 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
783 if (WARN_ON_ONCE(pmd_bad(*pmd)))
784 return NULL;
785
786 ptep = pte_offset_kernel(pmd, addr);
787 pte = ptep_get(ptep);
788 if (pte_present(pte))
789 page = pte_page(pte);
790
791 return page;
792}
793EXPORT_SYMBOL(vmalloc_to_page);
794
795/*
796 * Map a vmalloc()-space virtual address to the physical page frame number.
797 */
798unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
799{
800 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
801}
802EXPORT_SYMBOL(vmalloc_to_pfn);
803
804
805/*** Global kva allocator ***/
806
807#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
808#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
809
810
811static DEFINE_SPINLOCK(free_vmap_area_lock);
812static bool vmap_initialized __read_mostly;
813
814/*
815 * This kmem_cache is used for vmap_area objects. Instead of
816 * allocating from slab we reuse an object from this cache to
817 * make things faster. Especially in "no edge" splitting of
818 * free block.
819 */
820static struct kmem_cache *vmap_area_cachep;
821
822/*
823 * This linked list is used in pair with free_vmap_area_root.
824 * It gives O(1) access to prev/next to perform fast coalescing.
825 */
826static LIST_HEAD(free_vmap_area_list);
827
828/*
829 * This augment red-black tree represents the free vmap space.
830 * All vmap_area objects in this tree are sorted by va->va_start
831 * address. It is used for allocation and merging when a vmap
832 * object is released.
833 *
834 * Each vmap_area node contains a maximum available free block
835 * of its sub-tree, right or left. Therefore it is possible to
836 * find a lowest match of free area.
837 */
838static struct rb_root free_vmap_area_root = RB_ROOT;
839
840/*
841 * Preload a CPU with one object for "no edge" split case. The
842 * aim is to get rid of allocations from the atomic context, thus
843 * to use more permissive allocation masks.
844 */
845static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
846
847/*
848 * This structure defines a single, solid model where a list and
849 * rb-tree are part of one entity protected by the lock. Nodes are
850 * sorted in ascending order, thus for O(1) access to left/right
851 * neighbors a list is used as well as for sequential traversal.
852 */
853struct rb_list {
854 struct rb_root root;
855 struct list_head head;
856 spinlock_t lock;
857};
858
859/*
860 * A fast size storage contains VAs up to 1M size. A pool consists
861 * of linked between each other ready to go VAs of certain sizes.
862 * An index in the pool-array corresponds to number of pages + 1.
863 */
864#define MAX_VA_SIZE_PAGES 256
865
866struct vmap_pool {
867 struct list_head head;
868 unsigned long len;
869};
870
871/*
872 * An effective vmap-node logic. Users make use of nodes instead
873 * of a global heap. It allows to balance an access and mitigate
874 * contention.
875 */
876static struct vmap_node {
877 /* Simple size segregated storage. */
878 struct vmap_pool pool[MAX_VA_SIZE_PAGES];
879 spinlock_t pool_lock;
880 bool skip_populate;
881
882 /* Bookkeeping data of this node. */
883 struct rb_list busy;
884 struct rb_list lazy;
885
886 /*
887 * Ready-to-free areas.
888 */
889 struct list_head purge_list;
890 struct work_struct purge_work;
891 unsigned long nr_purged;
892} single;
893
894/*
895 * Initial setup consists of one single node, i.e. a balancing
896 * is fully disabled. Later on, after vmap is initialized these
897 * parameters are updated based on a system capacity.
898 */
899static struct vmap_node *vmap_nodes = &single;
900static __read_mostly unsigned int nr_vmap_nodes = 1;
901static __read_mostly unsigned int vmap_zone_size = 1;
902
903static inline unsigned int
904addr_to_node_id(unsigned long addr)
905{
906 return (addr / vmap_zone_size) % nr_vmap_nodes;
907}
908
909static inline struct vmap_node *
910addr_to_node(unsigned long addr)
911{
912 return &vmap_nodes[addr_to_node_id(addr)];
913}
914
915static inline struct vmap_node *
916id_to_node(unsigned int id)
917{
918 return &vmap_nodes[id % nr_vmap_nodes];
919}
920
921/*
922 * We use the value 0 to represent "no node", that is why
923 * an encoded value will be the node-id incremented by 1.
924 * It is always greater then 0. A valid node_id which can
925 * be encoded is [0:nr_vmap_nodes - 1]. If a passed node_id
926 * is not valid 0 is returned.
927 */
928static unsigned int
929encode_vn_id(unsigned int node_id)
930{
931 /* Can store U8_MAX [0:254] nodes. */
932 if (node_id < nr_vmap_nodes)
933 return (node_id + 1) << BITS_PER_BYTE;
934
935 /* Warn and no node encoded. */
936 WARN_ONCE(1, "Encode wrong node id (%u)\n", node_id);
937 return 0;
938}
939
940/*
941 * Returns an encoded node-id, the valid range is within
942 * [0:nr_vmap_nodes-1] values. Otherwise nr_vmap_nodes is
943 * returned if extracted data is wrong.
944 */
945static unsigned int
946decode_vn_id(unsigned int val)
947{
948 unsigned int node_id = (val >> BITS_PER_BYTE) - 1;
949
950 /* Can store U8_MAX [0:254] nodes. */
951 if (node_id < nr_vmap_nodes)
952 return node_id;
953
954 /* If it was _not_ zero, warn. */
955 WARN_ONCE(node_id != UINT_MAX,
956 "Decode wrong node id (%d)\n", node_id);
957
958 return nr_vmap_nodes;
959}
960
961static bool
962is_vn_id_valid(unsigned int node_id)
963{
964 if (node_id < nr_vmap_nodes)
965 return true;
966
967 return false;
968}
969
970static __always_inline unsigned long
971va_size(struct vmap_area *va)
972{
973 return (va->va_end - va->va_start);
974}
975
976static __always_inline unsigned long
977get_subtree_max_size(struct rb_node *node)
978{
979 struct vmap_area *va;
980
981 va = rb_entry_safe(node, struct vmap_area, rb_node);
982 return va ? va->subtree_max_size : 0;
983}
984
985RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
986 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
987
988static void reclaim_and_purge_vmap_areas(void);
989static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
990static void drain_vmap_area_work(struct work_struct *work);
991static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work);
992
993static atomic_long_t nr_vmalloc_pages;
994
995unsigned long vmalloc_nr_pages(void)
996{
997 return atomic_long_read(&nr_vmalloc_pages);
998}
999
1000static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root)
1001{
1002 struct rb_node *n = root->rb_node;
1003
1004 addr = (unsigned long)kasan_reset_tag((void *)addr);
1005
1006 while (n) {
1007 struct vmap_area *va;
1008
1009 va = rb_entry(n, struct vmap_area, rb_node);
1010 if (addr < va->va_start)
1011 n = n->rb_left;
1012 else if (addr >= va->va_end)
1013 n = n->rb_right;
1014 else
1015 return va;
1016 }
1017
1018 return NULL;
1019}
1020
1021/* Look up the first VA which satisfies addr < va_end, NULL if none. */
1022static struct vmap_area *
1023__find_vmap_area_exceed_addr(unsigned long addr, struct rb_root *root)
1024{
1025 struct vmap_area *va = NULL;
1026 struct rb_node *n = root->rb_node;
1027
1028 addr = (unsigned long)kasan_reset_tag((void *)addr);
1029
1030 while (n) {
1031 struct vmap_area *tmp;
1032
1033 tmp = rb_entry(n, struct vmap_area, rb_node);
1034 if (tmp->va_end > addr) {
1035 va = tmp;
1036 if (tmp->va_start <= addr)
1037 break;
1038
1039 n = n->rb_left;
1040 } else
1041 n = n->rb_right;
1042 }
1043
1044 return va;
1045}
1046
1047/*
1048 * Returns a node where a first VA, that satisfies addr < va_end, resides.
1049 * If success, a node is locked. A user is responsible to unlock it when a
1050 * VA is no longer needed to be accessed.
1051 *
1052 * Returns NULL if nothing found.
1053 */
1054static struct vmap_node *
1055find_vmap_area_exceed_addr_lock(unsigned long addr, struct vmap_area **va)
1056{
1057 unsigned long va_start_lowest;
1058 struct vmap_node *vn;
1059 int i;
1060
1061repeat:
1062 for (i = 0, va_start_lowest = 0; i < nr_vmap_nodes; i++) {
1063 vn = &vmap_nodes[i];
1064
1065 spin_lock(&vn->busy.lock);
1066 *va = __find_vmap_area_exceed_addr(addr, &vn->busy.root);
1067
1068 if (*va)
1069 if (!va_start_lowest || (*va)->va_start < va_start_lowest)
1070 va_start_lowest = (*va)->va_start;
1071 spin_unlock(&vn->busy.lock);
1072 }
1073
1074 /*
1075 * Check if found VA exists, it might have gone away. In this case we
1076 * repeat the search because a VA has been removed concurrently and we
1077 * need to proceed to the next one, which is a rare case.
1078 */
1079 if (va_start_lowest) {
1080 vn = addr_to_node(va_start_lowest);
1081
1082 spin_lock(&vn->busy.lock);
1083 *va = __find_vmap_area(va_start_lowest, &vn->busy.root);
1084
1085 if (*va)
1086 return vn;
1087
1088 spin_unlock(&vn->busy.lock);
1089 goto repeat;
1090 }
1091
1092 return NULL;
1093}
1094
1095/*
1096 * This function returns back addresses of parent node
1097 * and its left or right link for further processing.
1098 *
1099 * Otherwise NULL is returned. In that case all further
1100 * steps regarding inserting of conflicting overlap range
1101 * have to be declined and actually considered as a bug.
1102 */
1103static __always_inline struct rb_node **
1104find_va_links(struct vmap_area *va,
1105 struct rb_root *root, struct rb_node *from,
1106 struct rb_node **parent)
1107{
1108 struct vmap_area *tmp_va;
1109 struct rb_node **link;
1110
1111 if (root) {
1112 link = &root->rb_node;
1113 if (unlikely(!*link)) {
1114 *parent = NULL;
1115 return link;
1116 }
1117 } else {
1118 link = &from;
1119 }
1120
1121 /*
1122 * Go to the bottom of the tree. When we hit the last point
1123 * we end up with parent rb_node and correct direction, i name
1124 * it link, where the new va->rb_node will be attached to.
1125 */
1126 do {
1127 tmp_va = rb_entry(*link, struct vmap_area, rb_node);
1128
1129 /*
1130 * During the traversal we also do some sanity check.
1131 * Trigger the BUG() if there are sides(left/right)
1132 * or full overlaps.
1133 */
1134 if (va->va_end <= tmp_va->va_start)
1135 link = &(*link)->rb_left;
1136 else if (va->va_start >= tmp_va->va_end)
1137 link = &(*link)->rb_right;
1138 else {
1139 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
1140 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
1141
1142 return NULL;
1143 }
1144 } while (*link);
1145
1146 *parent = &tmp_va->rb_node;
1147 return link;
1148}
1149
1150static __always_inline struct list_head *
1151get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
1152{
1153 struct list_head *list;
1154
1155 if (unlikely(!parent))
1156 /*
1157 * The red-black tree where we try to find VA neighbors
1158 * before merging or inserting is empty, i.e. it means
1159 * there is no free vmap space. Normally it does not
1160 * happen but we handle this case anyway.
1161 */
1162 return NULL;
1163
1164 list = &rb_entry(parent, struct vmap_area, rb_node)->list;
1165 return (&parent->rb_right == link ? list->next : list);
1166}
1167
1168static __always_inline void
1169__link_va(struct vmap_area *va, struct rb_root *root,
1170 struct rb_node *parent, struct rb_node **link,
1171 struct list_head *head, bool augment)
1172{
1173 /*
1174 * VA is still not in the list, but we can
1175 * identify its future previous list_head node.
1176 */
1177 if (likely(parent)) {
1178 head = &rb_entry(parent, struct vmap_area, rb_node)->list;
1179 if (&parent->rb_right != link)
1180 head = head->prev;
1181 }
1182
1183 /* Insert to the rb-tree */
1184 rb_link_node(&va->rb_node, parent, link);
1185 if (augment) {
1186 /*
1187 * Some explanation here. Just perform simple insertion
1188 * to the tree. We do not set va->subtree_max_size to
1189 * its current size before calling rb_insert_augmented().
1190 * It is because we populate the tree from the bottom
1191 * to parent levels when the node _is_ in the tree.
1192 *
1193 * Therefore we set subtree_max_size to zero after insertion,
1194 * to let __augment_tree_propagate_from() puts everything to
1195 * the correct order later on.
1196 */
1197 rb_insert_augmented(&va->rb_node,
1198 root, &free_vmap_area_rb_augment_cb);
1199 va->subtree_max_size = 0;
1200 } else {
1201 rb_insert_color(&va->rb_node, root);
1202 }
1203
1204 /* Address-sort this list */
1205 list_add(&va->list, head);
1206}
1207
1208static __always_inline void
1209link_va(struct vmap_area *va, struct rb_root *root,
1210 struct rb_node *parent, struct rb_node **link,
1211 struct list_head *head)
1212{
1213 __link_va(va, root, parent, link, head, false);
1214}
1215
1216static __always_inline void
1217link_va_augment(struct vmap_area *va, struct rb_root *root,
1218 struct rb_node *parent, struct rb_node **link,
1219 struct list_head *head)
1220{
1221 __link_va(va, root, parent, link, head, true);
1222}
1223
1224static __always_inline void
1225__unlink_va(struct vmap_area *va, struct rb_root *root, bool augment)
1226{
1227 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
1228 return;
1229
1230 if (augment)
1231 rb_erase_augmented(&va->rb_node,
1232 root, &free_vmap_area_rb_augment_cb);
1233 else
1234 rb_erase(&va->rb_node, root);
1235
1236 list_del_init(&va->list);
1237 RB_CLEAR_NODE(&va->rb_node);
1238}
1239
1240static __always_inline void
1241unlink_va(struct vmap_area *va, struct rb_root *root)
1242{
1243 __unlink_va(va, root, false);
1244}
1245
1246static __always_inline void
1247unlink_va_augment(struct vmap_area *va, struct rb_root *root)
1248{
1249 __unlink_va(va, root, true);
1250}
1251
1252#if DEBUG_AUGMENT_PROPAGATE_CHECK
1253/*
1254 * Gets called when remove the node and rotate.
1255 */
1256static __always_inline unsigned long
1257compute_subtree_max_size(struct vmap_area *va)
1258{
1259 return max3(va_size(va),
1260 get_subtree_max_size(va->rb_node.rb_left),
1261 get_subtree_max_size(va->rb_node.rb_right));
1262}
1263
1264static void
1265augment_tree_propagate_check(void)
1266{
1267 struct vmap_area *va;
1268 unsigned long computed_size;
1269
1270 list_for_each_entry(va, &free_vmap_area_list, list) {
1271 computed_size = compute_subtree_max_size(va);
1272 if (computed_size != va->subtree_max_size)
1273 pr_emerg("tree is corrupted: %lu, %lu\n",
1274 va_size(va), va->subtree_max_size);
1275 }
1276}
1277#endif
1278
1279/*
1280 * This function populates subtree_max_size from bottom to upper
1281 * levels starting from VA point. The propagation must be done
1282 * when VA size is modified by changing its va_start/va_end. Or
1283 * in case of newly inserting of VA to the tree.
1284 *
1285 * It means that __augment_tree_propagate_from() must be called:
1286 * - After VA has been inserted to the tree(free path);
1287 * - After VA has been shrunk(allocation path);
1288 * - After VA has been increased(merging path).
1289 *
1290 * Please note that, it does not mean that upper parent nodes
1291 * and their subtree_max_size are recalculated all the time up
1292 * to the root node.
1293 *
1294 * 4--8
1295 * /\
1296 * / \
1297 * / \
1298 * 2--2 8--8
1299 *
1300 * For example if we modify the node 4, shrinking it to 2, then
1301 * no any modification is required. If we shrink the node 2 to 1
1302 * its subtree_max_size is updated only, and set to 1. If we shrink
1303 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
1304 * node becomes 4--6.
1305 */
1306static __always_inline void
1307augment_tree_propagate_from(struct vmap_area *va)
1308{
1309 /*
1310 * Populate the tree from bottom towards the root until
1311 * the calculated maximum available size of checked node
1312 * is equal to its current one.
1313 */
1314 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL);
1315
1316#if DEBUG_AUGMENT_PROPAGATE_CHECK
1317 augment_tree_propagate_check();
1318#endif
1319}
1320
1321static void
1322insert_vmap_area(struct vmap_area *va,
1323 struct rb_root *root, struct list_head *head)
1324{
1325 struct rb_node **link;
1326 struct rb_node *parent;
1327
1328 link = find_va_links(va, root, NULL, &parent);
1329 if (link)
1330 link_va(va, root, parent, link, head);
1331}
1332
1333static void
1334insert_vmap_area_augment(struct vmap_area *va,
1335 struct rb_node *from, struct rb_root *root,
1336 struct list_head *head)
1337{
1338 struct rb_node **link;
1339 struct rb_node *parent;
1340
1341 if (from)
1342 link = find_va_links(va, NULL, from, &parent);
1343 else
1344 link = find_va_links(va, root, NULL, &parent);
1345
1346 if (link) {
1347 link_va_augment(va, root, parent, link, head);
1348 augment_tree_propagate_from(va);
1349 }
1350}
1351
1352/*
1353 * Merge de-allocated chunk of VA memory with previous
1354 * and next free blocks. If coalesce is not done a new
1355 * free area is inserted. If VA has been merged, it is
1356 * freed.
1357 *
1358 * Please note, it can return NULL in case of overlap
1359 * ranges, followed by WARN() report. Despite it is a
1360 * buggy behaviour, a system can be alive and keep
1361 * ongoing.
1362 */
1363static __always_inline struct vmap_area *
1364__merge_or_add_vmap_area(struct vmap_area *va,
1365 struct rb_root *root, struct list_head *head, bool augment)
1366{
1367 struct vmap_area *sibling;
1368 struct list_head *next;
1369 struct rb_node **link;
1370 struct rb_node *parent;
1371 bool merged = false;
1372
1373 /*
1374 * Find a place in the tree where VA potentially will be
1375 * inserted, unless it is merged with its sibling/siblings.
1376 */
1377 link = find_va_links(va, root, NULL, &parent);
1378 if (!link)
1379 return NULL;
1380
1381 /*
1382 * Get next node of VA to check if merging can be done.
1383 */
1384 next = get_va_next_sibling(parent, link);
1385 if (unlikely(next == NULL))
1386 goto insert;
1387
1388 /*
1389 * start end
1390 * | |
1391 * |<------VA------>|<-----Next----->|
1392 * | |
1393 * start end
1394 */
1395 if (next != head) {
1396 sibling = list_entry(next, struct vmap_area, list);
1397 if (sibling->va_start == va->va_end) {
1398 sibling->va_start = va->va_start;
1399
1400 /* Free vmap_area object. */
1401 kmem_cache_free(vmap_area_cachep, va);
1402
1403 /* Point to the new merged area. */
1404 va = sibling;
1405 merged = true;
1406 }
1407 }
1408
1409 /*
1410 * start end
1411 * | |
1412 * |<-----Prev----->|<------VA------>|
1413 * | |
1414 * start end
1415 */
1416 if (next->prev != head) {
1417 sibling = list_entry(next->prev, struct vmap_area, list);
1418 if (sibling->va_end == va->va_start) {
1419 /*
1420 * If both neighbors are coalesced, it is important
1421 * to unlink the "next" node first, followed by merging
1422 * with "previous" one. Otherwise the tree might not be
1423 * fully populated if a sibling's augmented value is
1424 * "normalized" because of rotation operations.
1425 */
1426 if (merged)
1427 __unlink_va(va, root, augment);
1428
1429 sibling->va_end = va->va_end;
1430
1431 /* Free vmap_area object. */
1432 kmem_cache_free(vmap_area_cachep, va);
1433
1434 /* Point to the new merged area. */
1435 va = sibling;
1436 merged = true;
1437 }
1438 }
1439
1440insert:
1441 if (!merged)
1442 __link_va(va, root, parent, link, head, augment);
1443
1444 return va;
1445}
1446
1447static __always_inline struct vmap_area *
1448merge_or_add_vmap_area(struct vmap_area *va,
1449 struct rb_root *root, struct list_head *head)
1450{
1451 return __merge_or_add_vmap_area(va, root, head, false);
1452}
1453
1454static __always_inline struct vmap_area *
1455merge_or_add_vmap_area_augment(struct vmap_area *va,
1456 struct rb_root *root, struct list_head *head)
1457{
1458 va = __merge_or_add_vmap_area(va, root, head, true);
1459 if (va)
1460 augment_tree_propagate_from(va);
1461
1462 return va;
1463}
1464
1465static __always_inline bool
1466is_within_this_va(struct vmap_area *va, unsigned long size,
1467 unsigned long align, unsigned long vstart)
1468{
1469 unsigned long nva_start_addr;
1470
1471 if (va->va_start > vstart)
1472 nva_start_addr = ALIGN(va->va_start, align);
1473 else
1474 nva_start_addr = ALIGN(vstart, align);
1475
1476 /* Can be overflowed due to big size or alignment. */
1477 if (nva_start_addr + size < nva_start_addr ||
1478 nva_start_addr < vstart)
1479 return false;
1480
1481 return (nva_start_addr + size <= va->va_end);
1482}
1483
1484/*
1485 * Find the first free block(lowest start address) in the tree,
1486 * that will accomplish the request corresponding to passing
1487 * parameters. Please note, with an alignment bigger than PAGE_SIZE,
1488 * a search length is adjusted to account for worst case alignment
1489 * overhead.
1490 */
1491static __always_inline struct vmap_area *
1492find_vmap_lowest_match(struct rb_root *root, unsigned long size,
1493 unsigned long align, unsigned long vstart, bool adjust_search_size)
1494{
1495 struct vmap_area *va;
1496 struct rb_node *node;
1497 unsigned long length;
1498
1499 /* Start from the root. */
1500 node = root->rb_node;
1501
1502 /* Adjust the search size for alignment overhead. */
1503 length = adjust_search_size ? size + align - 1 : size;
1504
1505 while (node) {
1506 va = rb_entry(node, struct vmap_area, rb_node);
1507
1508 if (get_subtree_max_size(node->rb_left) >= length &&
1509 vstart < va->va_start) {
1510 node = node->rb_left;
1511 } else {
1512 if (is_within_this_va(va, size, align, vstart))
1513 return va;
1514
1515 /*
1516 * Does not make sense to go deeper towards the right
1517 * sub-tree if it does not have a free block that is
1518 * equal or bigger to the requested search length.
1519 */
1520 if (get_subtree_max_size(node->rb_right) >= length) {
1521 node = node->rb_right;
1522 continue;
1523 }
1524
1525 /*
1526 * OK. We roll back and find the first right sub-tree,
1527 * that will satisfy the search criteria. It can happen
1528 * due to "vstart" restriction or an alignment overhead
1529 * that is bigger then PAGE_SIZE.
1530 */
1531 while ((node = rb_parent(node))) {
1532 va = rb_entry(node, struct vmap_area, rb_node);
1533 if (is_within_this_va(va, size, align, vstart))
1534 return va;
1535
1536 if (get_subtree_max_size(node->rb_right) >= length &&
1537 vstart <= va->va_start) {
1538 /*
1539 * Shift the vstart forward. Please note, we update it with
1540 * parent's start address adding "1" because we do not want
1541 * to enter same sub-tree after it has already been checked
1542 * and no suitable free block found there.
1543 */
1544 vstart = va->va_start + 1;
1545 node = node->rb_right;
1546 break;
1547 }
1548 }
1549 }
1550 }
1551
1552 return NULL;
1553}
1554
1555#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1556#include <linux/random.h>
1557
1558static struct vmap_area *
1559find_vmap_lowest_linear_match(struct list_head *head, unsigned long size,
1560 unsigned long align, unsigned long vstart)
1561{
1562 struct vmap_area *va;
1563
1564 list_for_each_entry(va, head, list) {
1565 if (!is_within_this_va(va, size, align, vstart))
1566 continue;
1567
1568 return va;
1569 }
1570
1571 return NULL;
1572}
1573
1574static void
1575find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head,
1576 unsigned long size, unsigned long align)
1577{
1578 struct vmap_area *va_1, *va_2;
1579 unsigned long vstart;
1580 unsigned int rnd;
1581
1582 get_random_bytes(&rnd, sizeof(rnd));
1583 vstart = VMALLOC_START + rnd;
1584
1585 va_1 = find_vmap_lowest_match(root, size, align, vstart, false);
1586 va_2 = find_vmap_lowest_linear_match(head, size, align, vstart);
1587
1588 if (va_1 != va_2)
1589 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
1590 va_1, va_2, vstart);
1591}
1592#endif
1593
1594enum fit_type {
1595 NOTHING_FIT = 0,
1596 FL_FIT_TYPE = 1, /* full fit */
1597 LE_FIT_TYPE = 2, /* left edge fit */
1598 RE_FIT_TYPE = 3, /* right edge fit */
1599 NE_FIT_TYPE = 4 /* no edge fit */
1600};
1601
1602static __always_inline enum fit_type
1603classify_va_fit_type(struct vmap_area *va,
1604 unsigned long nva_start_addr, unsigned long size)
1605{
1606 enum fit_type type;
1607
1608 /* Check if it is within VA. */
1609 if (nva_start_addr < va->va_start ||
1610 nva_start_addr + size > va->va_end)
1611 return NOTHING_FIT;
1612
1613 /* Now classify. */
1614 if (va->va_start == nva_start_addr) {
1615 if (va->va_end == nva_start_addr + size)
1616 type = FL_FIT_TYPE;
1617 else
1618 type = LE_FIT_TYPE;
1619 } else if (va->va_end == nva_start_addr + size) {
1620 type = RE_FIT_TYPE;
1621 } else {
1622 type = NE_FIT_TYPE;
1623 }
1624
1625 return type;
1626}
1627
1628static __always_inline int
1629va_clip(struct rb_root *root, struct list_head *head,
1630 struct vmap_area *va, unsigned long nva_start_addr,
1631 unsigned long size)
1632{
1633 struct vmap_area *lva = NULL;
1634 enum fit_type type = classify_va_fit_type(va, nva_start_addr, size);
1635
1636 if (type == FL_FIT_TYPE) {
1637 /*
1638 * No need to split VA, it fully fits.
1639 *
1640 * | |
1641 * V NVA V
1642 * |---------------|
1643 */
1644 unlink_va_augment(va, root);
1645 kmem_cache_free(vmap_area_cachep, va);
1646 } else if (type == LE_FIT_TYPE) {
1647 /*
1648 * Split left edge of fit VA.
1649 *
1650 * | |
1651 * V NVA V R
1652 * |-------|-------|
1653 */
1654 va->va_start += size;
1655 } else if (type == RE_FIT_TYPE) {
1656 /*
1657 * Split right edge of fit VA.
1658 *
1659 * | |
1660 * L V NVA V
1661 * |-------|-------|
1662 */
1663 va->va_end = nva_start_addr;
1664 } else if (type == NE_FIT_TYPE) {
1665 /*
1666 * Split no edge of fit VA.
1667 *
1668 * | |
1669 * L V NVA V R
1670 * |---|-------|---|
1671 */
1672 lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
1673 if (unlikely(!lva)) {
1674 /*
1675 * For percpu allocator we do not do any pre-allocation
1676 * and leave it as it is. The reason is it most likely
1677 * never ends up with NE_FIT_TYPE splitting. In case of
1678 * percpu allocations offsets and sizes are aligned to
1679 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
1680 * are its main fitting cases.
1681 *
1682 * There are a few exceptions though, as an example it is
1683 * a first allocation (early boot up) when we have "one"
1684 * big free space that has to be split.
1685 *
1686 * Also we can hit this path in case of regular "vmap"
1687 * allocations, if "this" current CPU was not preloaded.
1688 * See the comment in alloc_vmap_area() why. If so, then
1689 * GFP_NOWAIT is used instead to get an extra object for
1690 * split purpose. That is rare and most time does not
1691 * occur.
1692 *
1693 * What happens if an allocation gets failed. Basically,
1694 * an "overflow" path is triggered to purge lazily freed
1695 * areas to free some memory, then, the "retry" path is
1696 * triggered to repeat one more time. See more details
1697 * in alloc_vmap_area() function.
1698 */
1699 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
1700 if (!lva)
1701 return -1;
1702 }
1703
1704 /*
1705 * Build the remainder.
1706 */
1707 lva->va_start = va->va_start;
1708 lva->va_end = nva_start_addr;
1709
1710 /*
1711 * Shrink this VA to remaining size.
1712 */
1713 va->va_start = nva_start_addr + size;
1714 } else {
1715 return -1;
1716 }
1717
1718 if (type != FL_FIT_TYPE) {
1719 augment_tree_propagate_from(va);
1720
1721 if (lva) /* type == NE_FIT_TYPE */
1722 insert_vmap_area_augment(lva, &va->rb_node, root, head);
1723 }
1724
1725 return 0;
1726}
1727
1728static unsigned long
1729va_alloc(struct vmap_area *va,
1730 struct rb_root *root, struct list_head *head,
1731 unsigned long size, unsigned long align,
1732 unsigned long vstart, unsigned long vend)
1733{
1734 unsigned long nva_start_addr;
1735 int ret;
1736
1737 if (va->va_start > vstart)
1738 nva_start_addr = ALIGN(va->va_start, align);
1739 else
1740 nva_start_addr = ALIGN(vstart, align);
1741
1742 /* Check the "vend" restriction. */
1743 if (nva_start_addr + size > vend)
1744 return vend;
1745
1746 /* Update the free vmap_area. */
1747 ret = va_clip(root, head, va, nva_start_addr, size);
1748 if (WARN_ON_ONCE(ret))
1749 return vend;
1750
1751 return nva_start_addr;
1752}
1753
1754/*
1755 * Returns a start address of the newly allocated area, if success.
1756 * Otherwise a vend is returned that indicates failure.
1757 */
1758static __always_inline unsigned long
1759__alloc_vmap_area(struct rb_root *root, struct list_head *head,
1760 unsigned long size, unsigned long align,
1761 unsigned long vstart, unsigned long vend)
1762{
1763 bool adjust_search_size = true;
1764 unsigned long nva_start_addr;
1765 struct vmap_area *va;
1766
1767 /*
1768 * Do not adjust when:
1769 * a) align <= PAGE_SIZE, because it does not make any sense.
1770 * All blocks(their start addresses) are at least PAGE_SIZE
1771 * aligned anyway;
1772 * b) a short range where a requested size corresponds to exactly
1773 * specified [vstart:vend] interval and an alignment > PAGE_SIZE.
1774 * With adjusted search length an allocation would not succeed.
1775 */
1776 if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size))
1777 adjust_search_size = false;
1778
1779 va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size);
1780 if (unlikely(!va))
1781 return vend;
1782
1783 nva_start_addr = va_alloc(va, root, head, size, align, vstart, vend);
1784 if (nva_start_addr == vend)
1785 return vend;
1786
1787#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1788 find_vmap_lowest_match_check(root, head, size, align);
1789#endif
1790
1791 return nva_start_addr;
1792}
1793
1794/*
1795 * Free a region of KVA allocated by alloc_vmap_area
1796 */
1797static void free_vmap_area(struct vmap_area *va)
1798{
1799 struct vmap_node *vn = addr_to_node(va->va_start);
1800
1801 /*
1802 * Remove from the busy tree/list.
1803 */
1804 spin_lock(&vn->busy.lock);
1805 unlink_va(va, &vn->busy.root);
1806 spin_unlock(&vn->busy.lock);
1807
1808 /*
1809 * Insert/Merge it back to the free tree/list.
1810 */
1811 spin_lock(&free_vmap_area_lock);
1812 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list);
1813 spin_unlock(&free_vmap_area_lock);
1814}
1815
1816static inline void
1817preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
1818{
1819 struct vmap_area *va = NULL, *tmp;
1820
1821 /*
1822 * Preload this CPU with one extra vmap_area object. It is used
1823 * when fit type of free area is NE_FIT_TYPE. It guarantees that
1824 * a CPU that does an allocation is preloaded.
1825 *
1826 * We do it in non-atomic context, thus it allows us to use more
1827 * permissive allocation masks to be more stable under low memory
1828 * condition and high memory pressure.
1829 */
1830 if (!this_cpu_read(ne_fit_preload_node))
1831 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1832
1833 spin_lock(lock);
1834
1835 tmp = NULL;
1836 if (va && !__this_cpu_try_cmpxchg(ne_fit_preload_node, &tmp, va))
1837 kmem_cache_free(vmap_area_cachep, va);
1838}
1839
1840static struct vmap_pool *
1841size_to_va_pool(struct vmap_node *vn, unsigned long size)
1842{
1843 unsigned int idx = (size - 1) / PAGE_SIZE;
1844
1845 if (idx < MAX_VA_SIZE_PAGES)
1846 return &vn->pool[idx];
1847
1848 return NULL;
1849}
1850
1851static bool
1852node_pool_add_va(struct vmap_node *n, struct vmap_area *va)
1853{
1854 struct vmap_pool *vp;
1855
1856 vp = size_to_va_pool(n, va_size(va));
1857 if (!vp)
1858 return false;
1859
1860 spin_lock(&n->pool_lock);
1861 list_add(&va->list, &vp->head);
1862 WRITE_ONCE(vp->len, vp->len + 1);
1863 spin_unlock(&n->pool_lock);
1864
1865 return true;
1866}
1867
1868static struct vmap_area *
1869node_pool_del_va(struct vmap_node *vn, unsigned long size,
1870 unsigned long align, unsigned long vstart,
1871 unsigned long vend)
1872{
1873 struct vmap_area *va = NULL;
1874 struct vmap_pool *vp;
1875 int err = 0;
1876
1877 vp = size_to_va_pool(vn, size);
1878 if (!vp || list_empty(&vp->head))
1879 return NULL;
1880
1881 spin_lock(&vn->pool_lock);
1882 if (!list_empty(&vp->head)) {
1883 va = list_first_entry(&vp->head, struct vmap_area, list);
1884
1885 if (IS_ALIGNED(va->va_start, align)) {
1886 /*
1887 * Do some sanity check and emit a warning
1888 * if one of below checks detects an error.
1889 */
1890 err |= (va_size(va) != size);
1891 err |= (va->va_start < vstart);
1892 err |= (va->va_end > vend);
1893
1894 if (!WARN_ON_ONCE(err)) {
1895 list_del_init(&va->list);
1896 WRITE_ONCE(vp->len, vp->len - 1);
1897 } else {
1898 va = NULL;
1899 }
1900 } else {
1901 list_move_tail(&va->list, &vp->head);
1902 va = NULL;
1903 }
1904 }
1905 spin_unlock(&vn->pool_lock);
1906
1907 return va;
1908}
1909
1910static struct vmap_area *
1911node_alloc(unsigned long size, unsigned long align,
1912 unsigned long vstart, unsigned long vend,
1913 unsigned long *addr, unsigned int *vn_id)
1914{
1915 struct vmap_area *va;
1916
1917 *vn_id = 0;
1918 *addr = vend;
1919
1920 /*
1921 * Fallback to a global heap if not vmalloc or there
1922 * is only one node.
1923 */
1924 if (vstart != VMALLOC_START || vend != VMALLOC_END ||
1925 nr_vmap_nodes == 1)
1926 return NULL;
1927
1928 *vn_id = raw_smp_processor_id() % nr_vmap_nodes;
1929 va = node_pool_del_va(id_to_node(*vn_id), size, align, vstart, vend);
1930 *vn_id = encode_vn_id(*vn_id);
1931
1932 if (va)
1933 *addr = va->va_start;
1934
1935 return va;
1936}
1937
1938static inline void setup_vmalloc_vm(struct vm_struct *vm,
1939 struct vmap_area *va, unsigned long flags, const void *caller)
1940{
1941 vm->flags = flags;
1942 vm->addr = (void *)va->va_start;
1943 vm->size = va_size(va);
1944 vm->caller = caller;
1945 va->vm = vm;
1946}
1947
1948/*
1949 * Allocate a region of KVA of the specified size and alignment, within the
1950 * vstart and vend. If vm is passed in, the two will also be bound.
1951 */
1952static struct vmap_area *alloc_vmap_area(unsigned long size,
1953 unsigned long align,
1954 unsigned long vstart, unsigned long vend,
1955 int node, gfp_t gfp_mask,
1956 unsigned long va_flags, struct vm_struct *vm)
1957{
1958 struct vmap_node *vn;
1959 struct vmap_area *va;
1960 unsigned long freed;
1961 unsigned long addr;
1962 unsigned int vn_id;
1963 int purged = 0;
1964 int ret;
1965
1966 if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
1967 return ERR_PTR(-EINVAL);
1968
1969 if (unlikely(!vmap_initialized))
1970 return ERR_PTR(-EBUSY);
1971
1972 might_sleep();
1973
1974 /*
1975 * If a VA is obtained from a global heap(if it fails here)
1976 * it is anyway marked with this "vn_id" so it is returned
1977 * to this pool's node later. Such way gives a possibility
1978 * to populate pools based on users demand.
1979 *
1980 * On success a ready to go VA is returned.
1981 */
1982 va = node_alloc(size, align, vstart, vend, &addr, &vn_id);
1983 if (!va) {
1984 gfp_mask = gfp_mask & GFP_RECLAIM_MASK;
1985
1986 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1987 if (unlikely(!va))
1988 return ERR_PTR(-ENOMEM);
1989
1990 /*
1991 * Only scan the relevant parts containing pointers to other objects
1992 * to avoid false negatives.
1993 */
1994 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask);
1995 }
1996
1997retry:
1998 if (addr == vend) {
1999 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node);
2000 addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list,
2001 size, align, vstart, vend);
2002 spin_unlock(&free_vmap_area_lock);
2003 }
2004
2005 trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend);
2006
2007 /*
2008 * If an allocation fails, the "vend" address is
2009 * returned. Therefore trigger the overflow path.
2010 */
2011 if (unlikely(addr == vend))
2012 goto overflow;
2013
2014 va->va_start = addr;
2015 va->va_end = addr + size;
2016 va->vm = NULL;
2017 va->flags = (va_flags | vn_id);
2018
2019 if (vm) {
2020 vm->addr = (void *)va->va_start;
2021 vm->size = va_size(va);
2022 va->vm = vm;
2023 }
2024
2025 vn = addr_to_node(va->va_start);
2026
2027 spin_lock(&vn->busy.lock);
2028 insert_vmap_area(va, &vn->busy.root, &vn->busy.head);
2029 spin_unlock(&vn->busy.lock);
2030
2031 BUG_ON(!IS_ALIGNED(va->va_start, align));
2032 BUG_ON(va->va_start < vstart);
2033 BUG_ON(va->va_end > vend);
2034
2035 ret = kasan_populate_vmalloc(addr, size);
2036 if (ret) {
2037 free_vmap_area(va);
2038 return ERR_PTR(ret);
2039 }
2040
2041 return va;
2042
2043overflow:
2044 if (!purged) {
2045 reclaim_and_purge_vmap_areas();
2046 purged = 1;
2047 goto retry;
2048 }
2049
2050 freed = 0;
2051 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
2052
2053 if (freed > 0) {
2054 purged = 0;
2055 goto retry;
2056 }
2057
2058 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
2059 pr_warn("vmalloc_node_range for size %lu failed: Address range restricted to %#lx - %#lx\n",
2060 size, vstart, vend);
2061
2062 kmem_cache_free(vmap_area_cachep, va);
2063 return ERR_PTR(-EBUSY);
2064}
2065
2066int register_vmap_purge_notifier(struct notifier_block *nb)
2067{
2068 return blocking_notifier_chain_register(&vmap_notify_list, nb);
2069}
2070EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
2071
2072int unregister_vmap_purge_notifier(struct notifier_block *nb)
2073{
2074 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
2075}
2076EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
2077
2078/*
2079 * lazy_max_pages is the maximum amount of virtual address space we gather up
2080 * before attempting to purge with a TLB flush.
2081 *
2082 * There is a tradeoff here: a larger number will cover more kernel page tables
2083 * and take slightly longer to purge, but it will linearly reduce the number of
2084 * global TLB flushes that must be performed. It would seem natural to scale
2085 * this number up linearly with the number of CPUs (because vmapping activity
2086 * could also scale linearly with the number of CPUs), however it is likely
2087 * that in practice, workloads might be constrained in other ways that mean
2088 * vmap activity will not scale linearly with CPUs. Also, I want to be
2089 * conservative and not introduce a big latency on huge systems, so go with
2090 * a less aggressive log scale. It will still be an improvement over the old
2091 * code, and it will be simple to change the scale factor if we find that it
2092 * becomes a problem on bigger systems.
2093 */
2094static unsigned long lazy_max_pages(void)
2095{
2096 unsigned int log;
2097
2098 log = fls(num_online_cpus());
2099
2100 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
2101}
2102
2103static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
2104
2105/*
2106 * Serialize vmap purging. There is no actual critical section protected
2107 * by this lock, but we want to avoid concurrent calls for performance
2108 * reasons and to make the pcpu_get_vm_areas more deterministic.
2109 */
2110static DEFINE_MUTEX(vmap_purge_lock);
2111
2112/* for per-CPU blocks */
2113static void purge_fragmented_blocks_allcpus(void);
2114static cpumask_t purge_nodes;
2115
2116static void
2117reclaim_list_global(struct list_head *head)
2118{
2119 struct vmap_area *va, *n;
2120
2121 if (list_empty(head))
2122 return;
2123
2124 spin_lock(&free_vmap_area_lock);
2125 list_for_each_entry_safe(va, n, head, list)
2126 merge_or_add_vmap_area_augment(va,
2127 &free_vmap_area_root, &free_vmap_area_list);
2128 spin_unlock(&free_vmap_area_lock);
2129}
2130
2131static void
2132decay_va_pool_node(struct vmap_node *vn, bool full_decay)
2133{
2134 LIST_HEAD(decay_list);
2135 struct rb_root decay_root = RB_ROOT;
2136 struct vmap_area *va, *nva;
2137 unsigned long n_decay;
2138 int i;
2139
2140 for (i = 0; i < MAX_VA_SIZE_PAGES; i++) {
2141 LIST_HEAD(tmp_list);
2142
2143 if (list_empty(&vn->pool[i].head))
2144 continue;
2145
2146 /* Detach the pool, so no-one can access it. */
2147 spin_lock(&vn->pool_lock);
2148 list_replace_init(&vn->pool[i].head, &tmp_list);
2149 spin_unlock(&vn->pool_lock);
2150
2151 if (full_decay)
2152 WRITE_ONCE(vn->pool[i].len, 0);
2153
2154 /* Decay a pool by ~25% out of left objects. */
2155 n_decay = vn->pool[i].len >> 2;
2156
2157 list_for_each_entry_safe(va, nva, &tmp_list, list) {
2158 list_del_init(&va->list);
2159 merge_or_add_vmap_area(va, &decay_root, &decay_list);
2160
2161 if (!full_decay) {
2162 WRITE_ONCE(vn->pool[i].len, vn->pool[i].len - 1);
2163
2164 if (!--n_decay)
2165 break;
2166 }
2167 }
2168
2169 /*
2170 * Attach the pool back if it has been partly decayed.
2171 * Please note, it is supposed that nobody(other contexts)
2172 * can populate the pool therefore a simple list replace
2173 * operation takes place here.
2174 */
2175 if (!full_decay && !list_empty(&tmp_list)) {
2176 spin_lock(&vn->pool_lock);
2177 list_replace_init(&tmp_list, &vn->pool[i].head);
2178 spin_unlock(&vn->pool_lock);
2179 }
2180 }
2181
2182 reclaim_list_global(&decay_list);
2183}
2184
2185static void
2186kasan_release_vmalloc_node(struct vmap_node *vn)
2187{
2188 struct vmap_area *va;
2189 unsigned long start, end;
2190
2191 start = list_first_entry(&vn->purge_list, struct vmap_area, list)->va_start;
2192 end = list_last_entry(&vn->purge_list, struct vmap_area, list)->va_end;
2193
2194 list_for_each_entry(va, &vn->purge_list, list) {
2195 if (is_vmalloc_or_module_addr((void *) va->va_start))
2196 kasan_release_vmalloc(va->va_start, va->va_end,
2197 va->va_start, va->va_end,
2198 KASAN_VMALLOC_PAGE_RANGE);
2199 }
2200
2201 kasan_release_vmalloc(start, end, start, end, KASAN_VMALLOC_TLB_FLUSH);
2202}
2203
2204static void purge_vmap_node(struct work_struct *work)
2205{
2206 struct vmap_node *vn = container_of(work,
2207 struct vmap_node, purge_work);
2208 unsigned long nr_purged_pages = 0;
2209 struct vmap_area *va, *n_va;
2210 LIST_HEAD(local_list);
2211
2212 if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
2213 kasan_release_vmalloc_node(vn);
2214
2215 vn->nr_purged = 0;
2216
2217 list_for_each_entry_safe(va, n_va, &vn->purge_list, list) {
2218 unsigned long nr = va_size(va) >> PAGE_SHIFT;
2219 unsigned int vn_id = decode_vn_id(va->flags);
2220
2221 list_del_init(&va->list);
2222
2223 nr_purged_pages += nr;
2224 vn->nr_purged++;
2225
2226 if (is_vn_id_valid(vn_id) && !vn->skip_populate)
2227 if (node_pool_add_va(vn, va))
2228 continue;
2229
2230 /* Go back to global. */
2231 list_add(&va->list, &local_list);
2232 }
2233
2234 atomic_long_sub(nr_purged_pages, &vmap_lazy_nr);
2235
2236 reclaim_list_global(&local_list);
2237}
2238
2239/*
2240 * Purges all lazily-freed vmap areas.
2241 */
2242static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end,
2243 bool full_pool_decay)
2244{
2245 unsigned long nr_purged_areas = 0;
2246 unsigned int nr_purge_helpers;
2247 unsigned int nr_purge_nodes;
2248 struct vmap_node *vn;
2249 int i;
2250
2251 lockdep_assert_held(&vmap_purge_lock);
2252
2253 /*
2254 * Use cpumask to mark which node has to be processed.
2255 */
2256 purge_nodes = CPU_MASK_NONE;
2257
2258 for (i = 0; i < nr_vmap_nodes; i++) {
2259 vn = &vmap_nodes[i];
2260
2261 INIT_LIST_HEAD(&vn->purge_list);
2262 vn->skip_populate = full_pool_decay;
2263 decay_va_pool_node(vn, full_pool_decay);
2264
2265 if (RB_EMPTY_ROOT(&vn->lazy.root))
2266 continue;
2267
2268 spin_lock(&vn->lazy.lock);
2269 WRITE_ONCE(vn->lazy.root.rb_node, NULL);
2270 list_replace_init(&vn->lazy.head, &vn->purge_list);
2271 spin_unlock(&vn->lazy.lock);
2272
2273 start = min(start, list_first_entry(&vn->purge_list,
2274 struct vmap_area, list)->va_start);
2275
2276 end = max(end, list_last_entry(&vn->purge_list,
2277 struct vmap_area, list)->va_end);
2278
2279 cpumask_set_cpu(i, &purge_nodes);
2280 }
2281
2282 nr_purge_nodes = cpumask_weight(&purge_nodes);
2283 if (nr_purge_nodes > 0) {
2284 flush_tlb_kernel_range(start, end);
2285
2286 /* One extra worker is per a lazy_max_pages() full set minus one. */
2287 nr_purge_helpers = atomic_long_read(&vmap_lazy_nr) / lazy_max_pages();
2288 nr_purge_helpers = clamp(nr_purge_helpers, 1U, nr_purge_nodes) - 1;
2289
2290 for_each_cpu(i, &purge_nodes) {
2291 vn = &vmap_nodes[i];
2292
2293 if (nr_purge_helpers > 0) {
2294 INIT_WORK(&vn->purge_work, purge_vmap_node);
2295
2296 if (cpumask_test_cpu(i, cpu_online_mask))
2297 schedule_work_on(i, &vn->purge_work);
2298 else
2299 schedule_work(&vn->purge_work);
2300
2301 nr_purge_helpers--;
2302 } else {
2303 vn->purge_work.func = NULL;
2304 purge_vmap_node(&vn->purge_work);
2305 nr_purged_areas += vn->nr_purged;
2306 }
2307 }
2308
2309 for_each_cpu(i, &purge_nodes) {
2310 vn = &vmap_nodes[i];
2311
2312 if (vn->purge_work.func) {
2313 flush_work(&vn->purge_work);
2314 nr_purged_areas += vn->nr_purged;
2315 }
2316 }
2317 }
2318
2319 trace_purge_vmap_area_lazy(start, end, nr_purged_areas);
2320 return nr_purged_areas > 0;
2321}
2322
2323/*
2324 * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list.
2325 */
2326static void reclaim_and_purge_vmap_areas(void)
2327
2328{
2329 mutex_lock(&vmap_purge_lock);
2330 purge_fragmented_blocks_allcpus();
2331 __purge_vmap_area_lazy(ULONG_MAX, 0, true);
2332 mutex_unlock(&vmap_purge_lock);
2333}
2334
2335static void drain_vmap_area_work(struct work_struct *work)
2336{
2337 mutex_lock(&vmap_purge_lock);
2338 __purge_vmap_area_lazy(ULONG_MAX, 0, false);
2339 mutex_unlock(&vmap_purge_lock);
2340}
2341
2342/*
2343 * Free a vmap area, caller ensuring that the area has been unmapped,
2344 * unlinked and flush_cache_vunmap had been called for the correct
2345 * range previously.
2346 */
2347static void free_vmap_area_noflush(struct vmap_area *va)
2348{
2349 unsigned long nr_lazy_max = lazy_max_pages();
2350 unsigned long va_start = va->va_start;
2351 unsigned int vn_id = decode_vn_id(va->flags);
2352 struct vmap_node *vn;
2353 unsigned long nr_lazy;
2354
2355 if (WARN_ON_ONCE(!list_empty(&va->list)))
2356 return;
2357
2358 nr_lazy = atomic_long_add_return(va_size(va) >> PAGE_SHIFT,
2359 &vmap_lazy_nr);
2360
2361 /*
2362 * If it was request by a certain node we would like to
2363 * return it to that node, i.e. its pool for later reuse.
2364 */
2365 vn = is_vn_id_valid(vn_id) ?
2366 id_to_node(vn_id):addr_to_node(va->va_start);
2367
2368 spin_lock(&vn->lazy.lock);
2369 insert_vmap_area(va, &vn->lazy.root, &vn->lazy.head);
2370 spin_unlock(&vn->lazy.lock);
2371
2372 trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max);
2373
2374 /* After this point, we may free va at any time */
2375 if (unlikely(nr_lazy > nr_lazy_max))
2376 schedule_work(&drain_vmap_work);
2377}
2378
2379/*
2380 * Free and unmap a vmap area
2381 */
2382static void free_unmap_vmap_area(struct vmap_area *va)
2383{
2384 flush_cache_vunmap(va->va_start, va->va_end);
2385 vunmap_range_noflush(va->va_start, va->va_end);
2386 if (debug_pagealloc_enabled_static())
2387 flush_tlb_kernel_range(va->va_start, va->va_end);
2388
2389 free_vmap_area_noflush(va);
2390}
2391
2392struct vmap_area *find_vmap_area(unsigned long addr)
2393{
2394 struct vmap_node *vn;
2395 struct vmap_area *va;
2396 int i, j;
2397
2398 if (unlikely(!vmap_initialized))
2399 return NULL;
2400
2401 /*
2402 * An addr_to_node_id(addr) converts an address to a node index
2403 * where a VA is located. If VA spans several zones and passed
2404 * addr is not the same as va->va_start, what is not common, we
2405 * may need to scan extra nodes. See an example:
2406 *
2407 * <----va---->
2408 * -|-----|-----|-----|-----|-
2409 * 1 2 0 1
2410 *
2411 * VA resides in node 1 whereas it spans 1, 2 an 0. If passed
2412 * addr is within 2 or 0 nodes we should do extra work.
2413 */
2414 i = j = addr_to_node_id(addr);
2415 do {
2416 vn = &vmap_nodes[i];
2417
2418 spin_lock(&vn->busy.lock);
2419 va = __find_vmap_area(addr, &vn->busy.root);
2420 spin_unlock(&vn->busy.lock);
2421
2422 if (va)
2423 return va;
2424 } while ((i = (i + 1) % nr_vmap_nodes) != j);
2425
2426 return NULL;
2427}
2428
2429static struct vmap_area *find_unlink_vmap_area(unsigned long addr)
2430{
2431 struct vmap_node *vn;
2432 struct vmap_area *va;
2433 int i, j;
2434
2435 /*
2436 * Check the comment in the find_vmap_area() about the loop.
2437 */
2438 i = j = addr_to_node_id(addr);
2439 do {
2440 vn = &vmap_nodes[i];
2441
2442 spin_lock(&vn->busy.lock);
2443 va = __find_vmap_area(addr, &vn->busy.root);
2444 if (va)
2445 unlink_va(va, &vn->busy.root);
2446 spin_unlock(&vn->busy.lock);
2447
2448 if (va)
2449 return va;
2450 } while ((i = (i + 1) % nr_vmap_nodes) != j);
2451
2452 return NULL;
2453}
2454
2455/*** Per cpu kva allocator ***/
2456
2457/*
2458 * vmap space is limited especially on 32 bit architectures. Ensure there is
2459 * room for at least 16 percpu vmap blocks per CPU.
2460 */
2461/*
2462 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
2463 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
2464 * instead (we just need a rough idea)
2465 */
2466#if BITS_PER_LONG == 32
2467#define VMALLOC_SPACE (128UL*1024*1024)
2468#else
2469#define VMALLOC_SPACE (128UL*1024*1024*1024)
2470#endif
2471
2472#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
2473#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
2474#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
2475#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
2476#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
2477#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
2478#define VMAP_BBMAP_BITS \
2479 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
2480 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
2481 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
2482
2483#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
2484
2485/*
2486 * Purge threshold to prevent overeager purging of fragmented blocks for
2487 * regular operations: Purge if vb->free is less than 1/4 of the capacity.
2488 */
2489#define VMAP_PURGE_THRESHOLD (VMAP_BBMAP_BITS / 4)
2490
2491#define VMAP_RAM 0x1 /* indicates vm_map_ram area*/
2492#define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/
2493#define VMAP_FLAGS_MASK 0x3
2494
2495struct vmap_block_queue {
2496 spinlock_t lock;
2497 struct list_head free;
2498
2499 /*
2500 * An xarray requires an extra memory dynamically to
2501 * be allocated. If it is an issue, we can use rb-tree
2502 * instead.
2503 */
2504 struct xarray vmap_blocks;
2505};
2506
2507struct vmap_block {
2508 spinlock_t lock;
2509 struct vmap_area *va;
2510 unsigned long free, dirty;
2511 DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS);
2512 unsigned long dirty_min, dirty_max; /*< dirty range */
2513 struct list_head free_list;
2514 struct rcu_head rcu_head;
2515 struct list_head purge;
2516 unsigned int cpu;
2517};
2518
2519/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
2520static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
2521
2522/*
2523 * In order to fast access to any "vmap_block" associated with a
2524 * specific address, we use a hash.
2525 *
2526 * A per-cpu vmap_block_queue is used in both ways, to serialize
2527 * an access to free block chains among CPUs(alloc path) and it
2528 * also acts as a vmap_block hash(alloc/free paths). It means we
2529 * overload it, since we already have the per-cpu array which is
2530 * used as a hash table. When used as a hash a 'cpu' passed to
2531 * per_cpu() is not actually a CPU but rather a hash index.
2532 *
2533 * A hash function is addr_to_vb_xa() which hashes any address
2534 * to a specific index(in a hash) it belongs to. This then uses a
2535 * per_cpu() macro to access an array with generated index.
2536 *
2537 * An example:
2538 *
2539 * CPU_1 CPU_2 CPU_0
2540 * | | |
2541 * V V V
2542 * 0 10 20 30 40 50 60
2543 * |------|------|------|------|------|------|...<vmap address space>
2544 * CPU0 CPU1 CPU2 CPU0 CPU1 CPU2
2545 *
2546 * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus
2547 * it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock;
2548 *
2549 * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus
2550 * it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock;
2551 *
2552 * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus
2553 * it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock.
2554 *
2555 * This technique almost always avoids lock contention on insert/remove,
2556 * however xarray spinlocks protect against any contention that remains.
2557 */
2558static struct xarray *
2559addr_to_vb_xa(unsigned long addr)
2560{
2561 int index = (addr / VMAP_BLOCK_SIZE) % nr_cpu_ids;
2562
2563 /*
2564 * Please note, nr_cpu_ids points on a highest set
2565 * possible bit, i.e. we never invoke cpumask_next()
2566 * if an index points on it which is nr_cpu_ids - 1.
2567 */
2568 if (!cpu_possible(index))
2569 index = cpumask_next(index, cpu_possible_mask);
2570
2571 return &per_cpu(vmap_block_queue, index).vmap_blocks;
2572}
2573
2574/*
2575 * We should probably have a fallback mechanism to allocate virtual memory
2576 * out of partially filled vmap blocks. However vmap block sizing should be
2577 * fairly reasonable according to the vmalloc size, so it shouldn't be a
2578 * big problem.
2579 */
2580
2581static unsigned long addr_to_vb_idx(unsigned long addr)
2582{
2583 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
2584 addr /= VMAP_BLOCK_SIZE;
2585 return addr;
2586}
2587
2588static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
2589{
2590 unsigned long addr;
2591
2592 addr = va_start + (pages_off << PAGE_SHIFT);
2593 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
2594 return (void *)addr;
2595}
2596
2597/**
2598 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
2599 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
2600 * @order: how many 2^order pages should be occupied in newly allocated block
2601 * @gfp_mask: flags for the page level allocator
2602 *
2603 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
2604 */
2605static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
2606{
2607 struct vmap_block_queue *vbq;
2608 struct vmap_block *vb;
2609 struct vmap_area *va;
2610 struct xarray *xa;
2611 unsigned long vb_idx;
2612 int node, err;
2613 void *vaddr;
2614
2615 node = numa_node_id();
2616
2617 vb = kmalloc_node(sizeof(struct vmap_block),
2618 gfp_mask & GFP_RECLAIM_MASK, node);
2619 if (unlikely(!vb))
2620 return ERR_PTR(-ENOMEM);
2621
2622 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
2623 VMALLOC_START, VMALLOC_END,
2624 node, gfp_mask,
2625 VMAP_RAM|VMAP_BLOCK, NULL);
2626 if (IS_ERR(va)) {
2627 kfree(vb);
2628 return ERR_CAST(va);
2629 }
2630
2631 vaddr = vmap_block_vaddr(va->va_start, 0);
2632 spin_lock_init(&vb->lock);
2633 vb->va = va;
2634 /* At least something should be left free */
2635 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
2636 bitmap_zero(vb->used_map, VMAP_BBMAP_BITS);
2637 vb->free = VMAP_BBMAP_BITS - (1UL << order);
2638 vb->dirty = 0;
2639 vb->dirty_min = VMAP_BBMAP_BITS;
2640 vb->dirty_max = 0;
2641 bitmap_set(vb->used_map, 0, (1UL << order));
2642 INIT_LIST_HEAD(&vb->free_list);
2643 vb->cpu = raw_smp_processor_id();
2644
2645 xa = addr_to_vb_xa(va->va_start);
2646 vb_idx = addr_to_vb_idx(va->va_start);
2647 err = xa_insert(xa, vb_idx, vb, gfp_mask);
2648 if (err) {
2649 kfree(vb);
2650 free_vmap_area(va);
2651 return ERR_PTR(err);
2652 }
2653 /*
2654 * list_add_tail_rcu could happened in another core
2655 * rather than vb->cpu due to task migration, which
2656 * is safe as list_add_tail_rcu will ensure the list's
2657 * integrity together with list_for_each_rcu from read
2658 * side.
2659 */
2660 vbq = per_cpu_ptr(&vmap_block_queue, vb->cpu);
2661 spin_lock(&vbq->lock);
2662 list_add_tail_rcu(&vb->free_list, &vbq->free);
2663 spin_unlock(&vbq->lock);
2664
2665 return vaddr;
2666}
2667
2668static void free_vmap_block(struct vmap_block *vb)
2669{
2670 struct vmap_node *vn;
2671 struct vmap_block *tmp;
2672 struct xarray *xa;
2673
2674 xa = addr_to_vb_xa(vb->va->va_start);
2675 tmp = xa_erase(xa, addr_to_vb_idx(vb->va->va_start));
2676 BUG_ON(tmp != vb);
2677
2678 vn = addr_to_node(vb->va->va_start);
2679 spin_lock(&vn->busy.lock);
2680 unlink_va(vb->va, &vn->busy.root);
2681 spin_unlock(&vn->busy.lock);
2682
2683 free_vmap_area_noflush(vb->va);
2684 kfree_rcu(vb, rcu_head);
2685}
2686
2687static bool purge_fragmented_block(struct vmap_block *vb,
2688 struct list_head *purge_list, bool force_purge)
2689{
2690 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, vb->cpu);
2691
2692 if (vb->free + vb->dirty != VMAP_BBMAP_BITS ||
2693 vb->dirty == VMAP_BBMAP_BITS)
2694 return false;
2695
2696 /* Don't overeagerly purge usable blocks unless requested */
2697 if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD))
2698 return false;
2699
2700 /* prevent further allocs after releasing lock */
2701 WRITE_ONCE(vb->free, 0);
2702 /* prevent purging it again */
2703 WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS);
2704 vb->dirty_min = 0;
2705 vb->dirty_max = VMAP_BBMAP_BITS;
2706 spin_lock(&vbq->lock);
2707 list_del_rcu(&vb->free_list);
2708 spin_unlock(&vbq->lock);
2709 list_add_tail(&vb->purge, purge_list);
2710 return true;
2711}
2712
2713static void free_purged_blocks(struct list_head *purge_list)
2714{
2715 struct vmap_block *vb, *n_vb;
2716
2717 list_for_each_entry_safe(vb, n_vb, purge_list, purge) {
2718 list_del(&vb->purge);
2719 free_vmap_block(vb);
2720 }
2721}
2722
2723static void purge_fragmented_blocks(int cpu)
2724{
2725 LIST_HEAD(purge);
2726 struct vmap_block *vb;
2727 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2728
2729 rcu_read_lock();
2730 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2731 unsigned long free = READ_ONCE(vb->free);
2732 unsigned long dirty = READ_ONCE(vb->dirty);
2733
2734 if (free + dirty != VMAP_BBMAP_BITS ||
2735 dirty == VMAP_BBMAP_BITS)
2736 continue;
2737
2738 spin_lock(&vb->lock);
2739 purge_fragmented_block(vb, &purge, true);
2740 spin_unlock(&vb->lock);
2741 }
2742 rcu_read_unlock();
2743 free_purged_blocks(&purge);
2744}
2745
2746static void purge_fragmented_blocks_allcpus(void)
2747{
2748 int cpu;
2749
2750 for_each_possible_cpu(cpu)
2751 purge_fragmented_blocks(cpu);
2752}
2753
2754static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
2755{
2756 struct vmap_block_queue *vbq;
2757 struct vmap_block *vb;
2758 void *vaddr = NULL;
2759 unsigned int order;
2760
2761 BUG_ON(offset_in_page(size));
2762 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2763 if (WARN_ON(size == 0)) {
2764 /*
2765 * Allocating 0 bytes isn't what caller wants since
2766 * get_order(0) returns funny result. Just warn and terminate
2767 * early.
2768 */
2769 return ERR_PTR(-EINVAL);
2770 }
2771 order = get_order(size);
2772
2773 rcu_read_lock();
2774 vbq = raw_cpu_ptr(&vmap_block_queue);
2775 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2776 unsigned long pages_off;
2777
2778 if (READ_ONCE(vb->free) < (1UL << order))
2779 continue;
2780
2781 spin_lock(&vb->lock);
2782 if (vb->free < (1UL << order)) {
2783 spin_unlock(&vb->lock);
2784 continue;
2785 }
2786
2787 pages_off = VMAP_BBMAP_BITS - vb->free;
2788 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
2789 WRITE_ONCE(vb->free, vb->free - (1UL << order));
2790 bitmap_set(vb->used_map, pages_off, (1UL << order));
2791 if (vb->free == 0) {
2792 spin_lock(&vbq->lock);
2793 list_del_rcu(&vb->free_list);
2794 spin_unlock(&vbq->lock);
2795 }
2796
2797 spin_unlock(&vb->lock);
2798 break;
2799 }
2800
2801 rcu_read_unlock();
2802
2803 /* Allocate new block if nothing was found */
2804 if (!vaddr)
2805 vaddr = new_vmap_block(order, gfp_mask);
2806
2807 return vaddr;
2808}
2809
2810static void vb_free(unsigned long addr, unsigned long size)
2811{
2812 unsigned long offset;
2813 unsigned int order;
2814 struct vmap_block *vb;
2815 struct xarray *xa;
2816
2817 BUG_ON(offset_in_page(size));
2818 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2819
2820 flush_cache_vunmap(addr, addr + size);
2821
2822 order = get_order(size);
2823 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
2824
2825 xa = addr_to_vb_xa(addr);
2826 vb = xa_load(xa, addr_to_vb_idx(addr));
2827
2828 spin_lock(&vb->lock);
2829 bitmap_clear(vb->used_map, offset, (1UL << order));
2830 spin_unlock(&vb->lock);
2831
2832 vunmap_range_noflush(addr, addr + size);
2833
2834 if (debug_pagealloc_enabled_static())
2835 flush_tlb_kernel_range(addr, addr + size);
2836
2837 spin_lock(&vb->lock);
2838
2839 /* Expand the not yet TLB flushed dirty range */
2840 vb->dirty_min = min(vb->dirty_min, offset);
2841 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
2842
2843 WRITE_ONCE(vb->dirty, vb->dirty + (1UL << order));
2844 if (vb->dirty == VMAP_BBMAP_BITS) {
2845 BUG_ON(vb->free);
2846 spin_unlock(&vb->lock);
2847 free_vmap_block(vb);
2848 } else
2849 spin_unlock(&vb->lock);
2850}
2851
2852static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
2853{
2854 LIST_HEAD(purge_list);
2855 int cpu;
2856
2857 if (unlikely(!vmap_initialized))
2858 return;
2859
2860 mutex_lock(&vmap_purge_lock);
2861
2862 for_each_possible_cpu(cpu) {
2863 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2864 struct vmap_block *vb;
2865 unsigned long idx;
2866
2867 rcu_read_lock();
2868 xa_for_each(&vbq->vmap_blocks, idx, vb) {
2869 spin_lock(&vb->lock);
2870
2871 /*
2872 * Try to purge a fragmented block first. If it's
2873 * not purgeable, check whether there is dirty
2874 * space to be flushed.
2875 */
2876 if (!purge_fragmented_block(vb, &purge_list, false) &&
2877 vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) {
2878 unsigned long va_start = vb->va->va_start;
2879 unsigned long s, e;
2880
2881 s = va_start + (vb->dirty_min << PAGE_SHIFT);
2882 e = va_start + (vb->dirty_max << PAGE_SHIFT);
2883
2884 start = min(s, start);
2885 end = max(e, end);
2886
2887 /* Prevent that this is flushed again */
2888 vb->dirty_min = VMAP_BBMAP_BITS;
2889 vb->dirty_max = 0;
2890
2891 flush = 1;
2892 }
2893 spin_unlock(&vb->lock);
2894 }
2895 rcu_read_unlock();
2896 }
2897 free_purged_blocks(&purge_list);
2898
2899 if (!__purge_vmap_area_lazy(start, end, false) && flush)
2900 flush_tlb_kernel_range(start, end);
2901 mutex_unlock(&vmap_purge_lock);
2902}
2903
2904/**
2905 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
2906 *
2907 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
2908 * to amortize TLB flushing overheads. What this means is that any page you
2909 * have now, may, in a former life, have been mapped into kernel virtual
2910 * address by the vmap layer and so there might be some CPUs with TLB entries
2911 * still referencing that page (additional to the regular 1:1 kernel mapping).
2912 *
2913 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
2914 * be sure that none of the pages we have control over will have any aliases
2915 * from the vmap layer.
2916 */
2917void vm_unmap_aliases(void)
2918{
2919 unsigned long start = ULONG_MAX, end = 0;
2920 int flush = 0;
2921
2922 _vm_unmap_aliases(start, end, flush);
2923}
2924EXPORT_SYMBOL_GPL(vm_unmap_aliases);
2925
2926/**
2927 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
2928 * @mem: the pointer returned by vm_map_ram
2929 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
2930 */
2931void vm_unmap_ram(const void *mem, unsigned int count)
2932{
2933 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2934 unsigned long addr = (unsigned long)kasan_reset_tag(mem);
2935 struct vmap_area *va;
2936
2937 might_sleep();
2938 BUG_ON(!addr);
2939 BUG_ON(addr < VMALLOC_START);
2940 BUG_ON(addr > VMALLOC_END);
2941 BUG_ON(!PAGE_ALIGNED(addr));
2942
2943 kasan_poison_vmalloc(mem, size);
2944
2945 if (likely(count <= VMAP_MAX_ALLOC)) {
2946 debug_check_no_locks_freed(mem, size);
2947 vb_free(addr, size);
2948 return;
2949 }
2950
2951 va = find_unlink_vmap_area(addr);
2952 if (WARN_ON_ONCE(!va))
2953 return;
2954
2955 debug_check_no_locks_freed((void *)va->va_start, va_size(va));
2956 free_unmap_vmap_area(va);
2957}
2958EXPORT_SYMBOL(vm_unmap_ram);
2959
2960/**
2961 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
2962 * @pages: an array of pointers to the pages to be mapped
2963 * @count: number of pages
2964 * @node: prefer to allocate data structures on this node
2965 *
2966 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
2967 * faster than vmap so it's good. But if you mix long-life and short-life
2968 * objects with vm_map_ram(), it could consume lots of address space through
2969 * fragmentation (especially on a 32bit machine). You could see failures in
2970 * the end. Please use this function for short-lived objects.
2971 *
2972 * Returns: a pointer to the address that has been mapped, or %NULL on failure
2973 */
2974void *vm_map_ram(struct page **pages, unsigned int count, int node)
2975{
2976 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2977 unsigned long addr;
2978 void *mem;
2979
2980 if (likely(count <= VMAP_MAX_ALLOC)) {
2981 mem = vb_alloc(size, GFP_KERNEL);
2982 if (IS_ERR(mem))
2983 return NULL;
2984 addr = (unsigned long)mem;
2985 } else {
2986 struct vmap_area *va;
2987 va = alloc_vmap_area(size, PAGE_SIZE,
2988 VMALLOC_START, VMALLOC_END,
2989 node, GFP_KERNEL, VMAP_RAM,
2990 NULL);
2991 if (IS_ERR(va))
2992 return NULL;
2993
2994 addr = va->va_start;
2995 mem = (void *)addr;
2996 }
2997
2998 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
2999 pages, PAGE_SHIFT) < 0) {
3000 vm_unmap_ram(mem, count);
3001 return NULL;
3002 }
3003
3004 /*
3005 * Mark the pages as accessible, now that they are mapped.
3006 * With hardware tag-based KASAN, marking is skipped for
3007 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
3008 */
3009 mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL);
3010
3011 return mem;
3012}
3013EXPORT_SYMBOL(vm_map_ram);
3014
3015static struct vm_struct *vmlist __initdata;
3016
3017static inline unsigned int vm_area_page_order(struct vm_struct *vm)
3018{
3019#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
3020 return vm->page_order;
3021#else
3022 return 0;
3023#endif
3024}
3025
3026unsigned int get_vm_area_page_order(struct vm_struct *vm)
3027{
3028 return vm_area_page_order(vm);
3029}
3030
3031static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
3032{
3033#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
3034 vm->page_order = order;
3035#else
3036 BUG_ON(order != 0);
3037#endif
3038}
3039
3040/**
3041 * vm_area_add_early - add vmap area early during boot
3042 * @vm: vm_struct to add
3043 *
3044 * This function is used to add fixed kernel vm area to vmlist before
3045 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
3046 * should contain proper values and the other fields should be zero.
3047 *
3048 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
3049 */
3050void __init vm_area_add_early(struct vm_struct *vm)
3051{
3052 struct vm_struct *tmp, **p;
3053
3054 BUG_ON(vmap_initialized);
3055 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
3056 if (tmp->addr >= vm->addr) {
3057 BUG_ON(tmp->addr < vm->addr + vm->size);
3058 break;
3059 } else
3060 BUG_ON(tmp->addr + tmp->size > vm->addr);
3061 }
3062 vm->next = *p;
3063 *p = vm;
3064}
3065
3066/**
3067 * vm_area_register_early - register vmap area early during boot
3068 * @vm: vm_struct to register
3069 * @align: requested alignment
3070 *
3071 * This function is used to register kernel vm area before
3072 * vmalloc_init() is called. @vm->size and @vm->flags should contain
3073 * proper values on entry and other fields should be zero. On return,
3074 * vm->addr contains the allocated address.
3075 *
3076 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
3077 */
3078void __init vm_area_register_early(struct vm_struct *vm, size_t align)
3079{
3080 unsigned long addr = ALIGN(VMALLOC_START, align);
3081 struct vm_struct *cur, **p;
3082
3083 BUG_ON(vmap_initialized);
3084
3085 for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) {
3086 if ((unsigned long)cur->addr - addr >= vm->size)
3087 break;
3088 addr = ALIGN((unsigned long)cur->addr + cur->size, align);
3089 }
3090
3091 BUG_ON(addr > VMALLOC_END - vm->size);
3092 vm->addr = (void *)addr;
3093 vm->next = *p;
3094 *p = vm;
3095 kasan_populate_early_vm_area_shadow(vm->addr, vm->size);
3096}
3097
3098static void clear_vm_uninitialized_flag(struct vm_struct *vm)
3099{
3100 /*
3101 * Before removing VM_UNINITIALIZED,
3102 * we should make sure that vm has proper values.
3103 * Pair with smp_rmb() in show_numa_info().
3104 */
3105 smp_wmb();
3106 vm->flags &= ~VM_UNINITIALIZED;
3107}
3108
3109struct vm_struct *__get_vm_area_node(unsigned long size,
3110 unsigned long align, unsigned long shift, unsigned long flags,
3111 unsigned long start, unsigned long end, int node,
3112 gfp_t gfp_mask, const void *caller)
3113{
3114 struct vmap_area *va;
3115 struct vm_struct *area;
3116 unsigned long requested_size = size;
3117
3118 BUG_ON(in_interrupt());
3119 size = ALIGN(size, 1ul << shift);
3120 if (unlikely(!size))
3121 return NULL;
3122
3123 if (flags & VM_IOREMAP)
3124 align = 1ul << clamp_t(int, get_count_order_long(size),
3125 PAGE_SHIFT, IOREMAP_MAX_ORDER);
3126
3127 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
3128 if (unlikely(!area))
3129 return NULL;
3130
3131 if (!(flags & VM_NO_GUARD))
3132 size += PAGE_SIZE;
3133
3134 area->flags = flags;
3135 area->caller = caller;
3136
3137 va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0, area);
3138 if (IS_ERR(va)) {
3139 kfree(area);
3140 return NULL;
3141 }
3142
3143 /*
3144 * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a
3145 * best-effort approach, as they can be mapped outside of vmalloc code.
3146 * For VM_ALLOC mappings, the pages are marked as accessible after
3147 * getting mapped in __vmalloc_node_range().
3148 * With hardware tag-based KASAN, marking is skipped for
3149 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
3150 */
3151 if (!(flags & VM_ALLOC))
3152 area->addr = kasan_unpoison_vmalloc(area->addr, requested_size,
3153 KASAN_VMALLOC_PROT_NORMAL);
3154
3155 return area;
3156}
3157
3158struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
3159 unsigned long start, unsigned long end,
3160 const void *caller)
3161{
3162 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end,
3163 NUMA_NO_NODE, GFP_KERNEL, caller);
3164}
3165
3166/**
3167 * get_vm_area - reserve a contiguous kernel virtual area
3168 * @size: size of the area
3169 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
3170 *
3171 * Search an area of @size in the kernel virtual mapping area,
3172 * and reserved it for out purposes. Returns the area descriptor
3173 * on success or %NULL on failure.
3174 *
3175 * Return: the area descriptor on success or %NULL on failure.
3176 */
3177struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
3178{
3179 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
3180 VMALLOC_START, VMALLOC_END,
3181 NUMA_NO_NODE, GFP_KERNEL,
3182 __builtin_return_address(0));
3183}
3184
3185struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
3186 const void *caller)
3187{
3188 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
3189 VMALLOC_START, VMALLOC_END,
3190 NUMA_NO_NODE, GFP_KERNEL, caller);
3191}
3192
3193/**
3194 * find_vm_area - find a continuous kernel virtual area
3195 * @addr: base address
3196 *
3197 * Search for the kernel VM area starting at @addr, and return it.
3198 * It is up to the caller to do all required locking to keep the returned
3199 * pointer valid.
3200 *
3201 * Return: the area descriptor on success or %NULL on failure.
3202 */
3203struct vm_struct *find_vm_area(const void *addr)
3204{
3205 struct vmap_area *va;
3206
3207 va = find_vmap_area((unsigned long)addr);
3208 if (!va)
3209 return NULL;
3210
3211 return va->vm;
3212}
3213
3214/**
3215 * remove_vm_area - find and remove a continuous kernel virtual area
3216 * @addr: base address
3217 *
3218 * Search for the kernel VM area starting at @addr, and remove it.
3219 * This function returns the found VM area, but using it is NOT safe
3220 * on SMP machines, except for its size or flags.
3221 *
3222 * Return: the area descriptor on success or %NULL on failure.
3223 */
3224struct vm_struct *remove_vm_area(const void *addr)
3225{
3226 struct vmap_area *va;
3227 struct vm_struct *vm;
3228
3229 might_sleep();
3230
3231 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
3232 addr))
3233 return NULL;
3234
3235 va = find_unlink_vmap_area((unsigned long)addr);
3236 if (!va || !va->vm)
3237 return NULL;
3238 vm = va->vm;
3239
3240 debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm));
3241 debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm));
3242 kasan_free_module_shadow(vm);
3243 kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm));
3244
3245 free_unmap_vmap_area(va);
3246 return vm;
3247}
3248
3249static inline void set_area_direct_map(const struct vm_struct *area,
3250 int (*set_direct_map)(struct page *page))
3251{
3252 int i;
3253
3254 /* HUGE_VMALLOC passes small pages to set_direct_map */
3255 for (i = 0; i < area->nr_pages; i++)
3256 if (page_address(area->pages[i]))
3257 set_direct_map(area->pages[i]);
3258}
3259
3260/*
3261 * Flush the vm mapping and reset the direct map.
3262 */
3263static void vm_reset_perms(struct vm_struct *area)
3264{
3265 unsigned long start = ULONG_MAX, end = 0;
3266 unsigned int page_order = vm_area_page_order(area);
3267 int flush_dmap = 0;
3268 int i;
3269
3270 /*
3271 * Find the start and end range of the direct mappings to make sure that
3272 * the vm_unmap_aliases() flush includes the direct map.
3273 */
3274 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
3275 unsigned long addr = (unsigned long)page_address(area->pages[i]);
3276
3277 if (addr) {
3278 unsigned long page_size;
3279
3280 page_size = PAGE_SIZE << page_order;
3281 start = min(addr, start);
3282 end = max(addr + page_size, end);
3283 flush_dmap = 1;
3284 }
3285 }
3286
3287 /*
3288 * Set direct map to something invalid so that it won't be cached if
3289 * there are any accesses after the TLB flush, then flush the TLB and
3290 * reset the direct map permissions to the default.
3291 */
3292 set_area_direct_map(area, set_direct_map_invalid_noflush);
3293 _vm_unmap_aliases(start, end, flush_dmap);
3294 set_area_direct_map(area, set_direct_map_default_noflush);
3295}
3296
3297static void delayed_vfree_work(struct work_struct *w)
3298{
3299 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
3300 struct llist_node *t, *llnode;
3301
3302 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
3303 vfree(llnode);
3304}
3305
3306/**
3307 * vfree_atomic - release memory allocated by vmalloc()
3308 * @addr: memory base address
3309 *
3310 * This one is just like vfree() but can be called in any atomic context
3311 * except NMIs.
3312 */
3313void vfree_atomic(const void *addr)
3314{
3315 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
3316
3317 BUG_ON(in_nmi());
3318 kmemleak_free(addr);
3319
3320 /*
3321 * Use raw_cpu_ptr() because this can be called from preemptible
3322 * context. Preemption is absolutely fine here, because the llist_add()
3323 * implementation is lockless, so it works even if we are adding to
3324 * another cpu's list. schedule_work() should be fine with this too.
3325 */
3326 if (addr && llist_add((struct llist_node *)addr, &p->list))
3327 schedule_work(&p->wq);
3328}
3329
3330/**
3331 * vfree - Release memory allocated by vmalloc()
3332 * @addr: Memory base address
3333 *
3334 * Free the virtually continuous memory area starting at @addr, as obtained
3335 * from one of the vmalloc() family of APIs. This will usually also free the
3336 * physical memory underlying the virtual allocation, but that memory is
3337 * reference counted, so it will not be freed until the last user goes away.
3338 *
3339 * If @addr is NULL, no operation is performed.
3340 *
3341 * Context:
3342 * May sleep if called *not* from interrupt context.
3343 * Must not be called in NMI context (strictly speaking, it could be
3344 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
3345 * conventions for vfree() arch-dependent would be a really bad idea).
3346 */
3347void vfree(const void *addr)
3348{
3349 struct vm_struct *vm;
3350 int i;
3351
3352 if (unlikely(in_interrupt())) {
3353 vfree_atomic(addr);
3354 return;
3355 }
3356
3357 BUG_ON(in_nmi());
3358 kmemleak_free(addr);
3359 might_sleep();
3360
3361 if (!addr)
3362 return;
3363
3364 vm = remove_vm_area(addr);
3365 if (unlikely(!vm)) {
3366 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
3367 addr);
3368 return;
3369 }
3370
3371 if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
3372 vm_reset_perms(vm);
3373 for (i = 0; i < vm->nr_pages; i++) {
3374 struct page *page = vm->pages[i];
3375
3376 BUG_ON(!page);
3377 if (!(vm->flags & VM_MAP_PUT_PAGES))
3378 mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
3379 /*
3380 * High-order allocs for huge vmallocs are split, so
3381 * can be freed as an array of order-0 allocations
3382 */
3383 __free_page(page);
3384 cond_resched();
3385 }
3386 if (!(vm->flags & VM_MAP_PUT_PAGES))
3387 atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages);
3388 kvfree(vm->pages);
3389 kfree(vm);
3390}
3391EXPORT_SYMBOL(vfree);
3392
3393/**
3394 * vunmap - release virtual mapping obtained by vmap()
3395 * @addr: memory base address
3396 *
3397 * Free the virtually contiguous memory area starting at @addr,
3398 * which was created from the page array passed to vmap().
3399 *
3400 * Must not be called in interrupt context.
3401 */
3402void vunmap(const void *addr)
3403{
3404 struct vm_struct *vm;
3405
3406 BUG_ON(in_interrupt());
3407 might_sleep();
3408
3409 if (!addr)
3410 return;
3411 vm = remove_vm_area(addr);
3412 if (unlikely(!vm)) {
3413 WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n",
3414 addr);
3415 return;
3416 }
3417 kfree(vm);
3418}
3419EXPORT_SYMBOL(vunmap);
3420
3421/**
3422 * vmap - map an array of pages into virtually contiguous space
3423 * @pages: array of page pointers
3424 * @count: number of pages to map
3425 * @flags: vm_area->flags
3426 * @prot: page protection for the mapping
3427 *
3428 * Maps @count pages from @pages into contiguous kernel virtual space.
3429 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
3430 * (which must be kmalloc or vmalloc memory) and one reference per pages in it
3431 * are transferred from the caller to vmap(), and will be freed / dropped when
3432 * vfree() is called on the return value.
3433 *
3434 * Return: the address of the area or %NULL on failure
3435 */
3436void *vmap(struct page **pages, unsigned int count,
3437 unsigned long flags, pgprot_t prot)
3438{
3439 struct vm_struct *area;
3440 unsigned long addr;
3441 unsigned long size; /* In bytes */
3442
3443 might_sleep();
3444
3445 if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS))
3446 return NULL;
3447
3448 /*
3449 * Your top guard is someone else's bottom guard. Not having a top
3450 * guard compromises someone else's mappings too.
3451 */
3452 if (WARN_ON_ONCE(flags & VM_NO_GUARD))
3453 flags &= ~VM_NO_GUARD;
3454
3455 if (count > totalram_pages())
3456 return NULL;
3457
3458 size = (unsigned long)count << PAGE_SHIFT;
3459 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
3460 if (!area)
3461 return NULL;
3462
3463 addr = (unsigned long)area->addr;
3464 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
3465 pages, PAGE_SHIFT) < 0) {
3466 vunmap(area->addr);
3467 return NULL;
3468 }
3469
3470 if (flags & VM_MAP_PUT_PAGES) {
3471 area->pages = pages;
3472 area->nr_pages = count;
3473 }
3474 return area->addr;
3475}
3476EXPORT_SYMBOL(vmap);
3477
3478#ifdef CONFIG_VMAP_PFN
3479struct vmap_pfn_data {
3480 unsigned long *pfns;
3481 pgprot_t prot;
3482 unsigned int idx;
3483};
3484
3485static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
3486{
3487 struct vmap_pfn_data *data = private;
3488 unsigned long pfn = data->pfns[data->idx];
3489 pte_t ptent;
3490
3491 if (WARN_ON_ONCE(pfn_valid(pfn)))
3492 return -EINVAL;
3493
3494 ptent = pte_mkspecial(pfn_pte(pfn, data->prot));
3495 set_pte_at(&init_mm, addr, pte, ptent);
3496
3497 data->idx++;
3498 return 0;
3499}
3500
3501/**
3502 * vmap_pfn - map an array of PFNs into virtually contiguous space
3503 * @pfns: array of PFNs
3504 * @count: number of pages to map
3505 * @prot: page protection for the mapping
3506 *
3507 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
3508 * the start address of the mapping.
3509 */
3510void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
3511{
3512 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) };
3513 struct vm_struct *area;
3514
3515 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP,
3516 __builtin_return_address(0));
3517 if (!area)
3518 return NULL;
3519 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
3520 count * PAGE_SIZE, vmap_pfn_apply, &data)) {
3521 free_vm_area(area);
3522 return NULL;
3523 }
3524
3525 flush_cache_vmap((unsigned long)area->addr,
3526 (unsigned long)area->addr + count * PAGE_SIZE);
3527
3528 return area->addr;
3529}
3530EXPORT_SYMBOL_GPL(vmap_pfn);
3531#endif /* CONFIG_VMAP_PFN */
3532
3533static inline unsigned int
3534vm_area_alloc_pages(gfp_t gfp, int nid,
3535 unsigned int order, unsigned int nr_pages, struct page **pages)
3536{
3537 unsigned int nr_allocated = 0;
3538 struct page *page;
3539 int i;
3540
3541 /*
3542 * For order-0 pages we make use of bulk allocator, if
3543 * the page array is partly or not at all populated due
3544 * to fails, fallback to a single page allocator that is
3545 * more permissive.
3546 */
3547 if (!order) {
3548 while (nr_allocated < nr_pages) {
3549 unsigned int nr, nr_pages_request;
3550
3551 /*
3552 * A maximum allowed request is hard-coded and is 100
3553 * pages per call. That is done in order to prevent a
3554 * long preemption off scenario in the bulk-allocator
3555 * so the range is [1:100].
3556 */
3557 nr_pages_request = min(100U, nr_pages - nr_allocated);
3558
3559 /* memory allocation should consider mempolicy, we can't
3560 * wrongly use nearest node when nid == NUMA_NO_NODE,
3561 * otherwise memory may be allocated in only one node,
3562 * but mempolicy wants to alloc memory by interleaving.
3563 */
3564 if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE)
3565 nr = alloc_pages_bulk_array_mempolicy_noprof(gfp,
3566 nr_pages_request,
3567 pages + nr_allocated);
3568 else
3569 nr = alloc_pages_bulk_array_node_noprof(gfp, nid,
3570 nr_pages_request,
3571 pages + nr_allocated);
3572
3573 nr_allocated += nr;
3574 cond_resched();
3575
3576 /*
3577 * If zero or pages were obtained partly,
3578 * fallback to a single page allocator.
3579 */
3580 if (nr != nr_pages_request)
3581 break;
3582 }
3583 }
3584
3585 /* High-order pages or fallback path if "bulk" fails. */
3586 while (nr_allocated < nr_pages) {
3587 if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current))
3588 break;
3589
3590 if (nid == NUMA_NO_NODE)
3591 page = alloc_pages_noprof(gfp, order);
3592 else
3593 page = alloc_pages_node_noprof(nid, gfp, order);
3594
3595 if (unlikely(!page))
3596 break;
3597
3598 /*
3599 * High-order allocations must be able to be treated as
3600 * independent small pages by callers (as they can with
3601 * small-page vmallocs). Some drivers do their own refcounting
3602 * on vmalloc_to_page() pages, some use page->mapping,
3603 * page->lru, etc.
3604 */
3605 if (order)
3606 split_page(page, order);
3607
3608 /*
3609 * Careful, we allocate and map page-order pages, but
3610 * tracking is done per PAGE_SIZE page so as to keep the
3611 * vm_struct APIs independent of the physical/mapped size.
3612 */
3613 for (i = 0; i < (1U << order); i++)
3614 pages[nr_allocated + i] = page + i;
3615
3616 cond_resched();
3617 nr_allocated += 1U << order;
3618 }
3619
3620 return nr_allocated;
3621}
3622
3623static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
3624 pgprot_t prot, unsigned int page_shift,
3625 int node)
3626{
3627 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
3628 bool nofail = gfp_mask & __GFP_NOFAIL;
3629 unsigned long addr = (unsigned long)area->addr;
3630 unsigned long size = get_vm_area_size(area);
3631 unsigned long array_size;
3632 unsigned int nr_small_pages = size >> PAGE_SHIFT;
3633 unsigned int page_order;
3634 unsigned int flags;
3635 int ret;
3636
3637 array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
3638
3639 if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
3640 gfp_mask |= __GFP_HIGHMEM;
3641
3642 /* Please note that the recursion is strictly bounded. */
3643 if (array_size > PAGE_SIZE) {
3644 area->pages = __vmalloc_node_noprof(array_size, 1, nested_gfp, node,
3645 area->caller);
3646 } else {
3647 area->pages = kmalloc_node_noprof(array_size, nested_gfp, node);
3648 }
3649
3650 if (!area->pages) {
3651 warn_alloc(gfp_mask, NULL,
3652 "vmalloc error: size %lu, failed to allocated page array size %lu",
3653 nr_small_pages * PAGE_SIZE, array_size);
3654 free_vm_area(area);
3655 return NULL;
3656 }
3657
3658 set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
3659 page_order = vm_area_page_order(area);
3660
3661 /*
3662 * High-order nofail allocations are really expensive and
3663 * potentially dangerous (pre-mature OOM, disruptive reclaim
3664 * and compaction etc.
3665 *
3666 * Please note, the __vmalloc_node_range_noprof() falls-back
3667 * to order-0 pages if high-order attempt is unsuccessful.
3668 */
3669 area->nr_pages = vm_area_alloc_pages((page_order ?
3670 gfp_mask & ~__GFP_NOFAIL : gfp_mask) | __GFP_NOWARN,
3671 node, page_order, nr_small_pages, area->pages);
3672
3673 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
3674 if (gfp_mask & __GFP_ACCOUNT) {
3675 int i;
3676
3677 for (i = 0; i < area->nr_pages; i++)
3678 mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1);
3679 }
3680
3681 /*
3682 * If not enough pages were obtained to accomplish an
3683 * allocation request, free them via vfree() if any.
3684 */
3685 if (area->nr_pages != nr_small_pages) {
3686 /*
3687 * vm_area_alloc_pages() can fail due to insufficient memory but
3688 * also:-
3689 *
3690 * - a pending fatal signal
3691 * - insufficient huge page-order pages
3692 *
3693 * Since we always retry allocations at order-0 in the huge page
3694 * case a warning for either is spurious.
3695 */
3696 if (!fatal_signal_pending(current) && page_order == 0)
3697 warn_alloc(gfp_mask, NULL,
3698 "vmalloc error: size %lu, failed to allocate pages",
3699 area->nr_pages * PAGE_SIZE);
3700 goto fail;
3701 }
3702
3703 /*
3704 * page tables allocations ignore external gfp mask, enforce it
3705 * by the scope API
3706 */
3707 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3708 flags = memalloc_nofs_save();
3709 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3710 flags = memalloc_noio_save();
3711
3712 do {
3713 ret = vmap_pages_range(addr, addr + size, prot, area->pages,
3714 page_shift);
3715 if (nofail && (ret < 0))
3716 schedule_timeout_uninterruptible(1);
3717 } while (nofail && (ret < 0));
3718
3719 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3720 memalloc_nofs_restore(flags);
3721 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3722 memalloc_noio_restore(flags);
3723
3724 if (ret < 0) {
3725 warn_alloc(gfp_mask, NULL,
3726 "vmalloc error: size %lu, failed to map pages",
3727 area->nr_pages * PAGE_SIZE);
3728 goto fail;
3729 }
3730
3731 return area->addr;
3732
3733fail:
3734 vfree(area->addr);
3735 return NULL;
3736}
3737
3738/**
3739 * __vmalloc_node_range - allocate virtually contiguous memory
3740 * @size: allocation size
3741 * @align: desired alignment
3742 * @start: vm area range start
3743 * @end: vm area range end
3744 * @gfp_mask: flags for the page level allocator
3745 * @prot: protection mask for the allocated pages
3746 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
3747 * @node: node to use for allocation or NUMA_NO_NODE
3748 * @caller: caller's return address
3749 *
3750 * Allocate enough pages to cover @size from the page level
3751 * allocator with @gfp_mask flags. Please note that the full set of gfp
3752 * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all
3753 * supported.
3754 * Zone modifiers are not supported. From the reclaim modifiers
3755 * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported)
3756 * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and
3757 * __GFP_RETRY_MAYFAIL are not supported).
3758 *
3759 * __GFP_NOWARN can be used to suppress failures messages.
3760 *
3761 * Map them into contiguous kernel virtual space, using a pagetable
3762 * protection of @prot.
3763 *
3764 * Return: the address of the area or %NULL on failure
3765 */
3766void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align,
3767 unsigned long start, unsigned long end, gfp_t gfp_mask,
3768 pgprot_t prot, unsigned long vm_flags, int node,
3769 const void *caller)
3770{
3771 struct vm_struct *area;
3772 void *ret;
3773 kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE;
3774 unsigned long real_size = size;
3775 unsigned long real_align = align;
3776 unsigned int shift = PAGE_SHIFT;
3777
3778 if (WARN_ON_ONCE(!size))
3779 return NULL;
3780
3781 if ((size >> PAGE_SHIFT) > totalram_pages()) {
3782 warn_alloc(gfp_mask, NULL,
3783 "vmalloc error: size %lu, exceeds total pages",
3784 real_size);
3785 return NULL;
3786 }
3787
3788 if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) {
3789 /*
3790 * Try huge pages. Only try for PAGE_KERNEL allocations,
3791 * others like modules don't yet expect huge pages in
3792 * their allocations due to apply_to_page_range not
3793 * supporting them.
3794 */
3795
3796 if (arch_vmap_pmd_supported(prot) && size >= PMD_SIZE)
3797 shift = PMD_SHIFT;
3798 else
3799 shift = arch_vmap_pte_supported_shift(size);
3800
3801 align = max(real_align, 1UL << shift);
3802 size = ALIGN(real_size, 1UL << shift);
3803 }
3804
3805again:
3806 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
3807 VM_UNINITIALIZED | vm_flags, start, end, node,
3808 gfp_mask, caller);
3809 if (!area) {
3810 bool nofail = gfp_mask & __GFP_NOFAIL;
3811 warn_alloc(gfp_mask, NULL,
3812 "vmalloc error: size %lu, vm_struct allocation failed%s",
3813 real_size, (nofail) ? ". Retrying." : "");
3814 if (nofail) {
3815 schedule_timeout_uninterruptible(1);
3816 goto again;
3817 }
3818 goto fail;
3819 }
3820
3821 /*
3822 * Prepare arguments for __vmalloc_area_node() and
3823 * kasan_unpoison_vmalloc().
3824 */
3825 if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) {
3826 if (kasan_hw_tags_enabled()) {
3827 /*
3828 * Modify protection bits to allow tagging.
3829 * This must be done before mapping.
3830 */
3831 prot = arch_vmap_pgprot_tagged(prot);
3832
3833 /*
3834 * Skip page_alloc poisoning and zeroing for physical
3835 * pages backing VM_ALLOC mapping. Memory is instead
3836 * poisoned and zeroed by kasan_unpoison_vmalloc().
3837 */
3838 gfp_mask |= __GFP_SKIP_KASAN | __GFP_SKIP_ZERO;
3839 }
3840
3841 /* Take note that the mapping is PAGE_KERNEL. */
3842 kasan_flags |= KASAN_VMALLOC_PROT_NORMAL;
3843 }
3844
3845 /* Allocate physical pages and map them into vmalloc space. */
3846 ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
3847 if (!ret)
3848 goto fail;
3849
3850 /*
3851 * Mark the pages as accessible, now that they are mapped.
3852 * The condition for setting KASAN_VMALLOC_INIT should complement the
3853 * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check
3854 * to make sure that memory is initialized under the same conditions.
3855 * Tag-based KASAN modes only assign tags to normal non-executable
3856 * allocations, see __kasan_unpoison_vmalloc().
3857 */
3858 kasan_flags |= KASAN_VMALLOC_VM_ALLOC;
3859 if (!want_init_on_free() && want_init_on_alloc(gfp_mask) &&
3860 (gfp_mask & __GFP_SKIP_ZERO))
3861 kasan_flags |= KASAN_VMALLOC_INIT;
3862 /* KASAN_VMALLOC_PROT_NORMAL already set if required. */
3863 area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags);
3864
3865 /*
3866 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
3867 * flag. It means that vm_struct is not fully initialized.
3868 * Now, it is fully initialized, so remove this flag here.
3869 */
3870 clear_vm_uninitialized_flag(area);
3871
3872 size = PAGE_ALIGN(size);
3873 if (!(vm_flags & VM_DEFER_KMEMLEAK))
3874 kmemleak_vmalloc(area, size, gfp_mask);
3875
3876 return area->addr;
3877
3878fail:
3879 if (shift > PAGE_SHIFT) {
3880 shift = PAGE_SHIFT;
3881 align = real_align;
3882 size = real_size;
3883 goto again;
3884 }
3885
3886 return NULL;
3887}
3888
3889/**
3890 * __vmalloc_node - allocate virtually contiguous memory
3891 * @size: allocation size
3892 * @align: desired alignment
3893 * @gfp_mask: flags for the page level allocator
3894 * @node: node to use for allocation or NUMA_NO_NODE
3895 * @caller: caller's return address
3896 *
3897 * Allocate enough pages to cover @size from the page level allocator with
3898 * @gfp_mask flags. Map them into contiguous kernel virtual space.
3899 *
3900 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
3901 * and __GFP_NOFAIL are not supported
3902 *
3903 * Any use of gfp flags outside of GFP_KERNEL should be consulted
3904 * with mm people.
3905 *
3906 * Return: pointer to the allocated memory or %NULL on error
3907 */
3908void *__vmalloc_node_noprof(unsigned long size, unsigned long align,
3909 gfp_t gfp_mask, int node, const void *caller)
3910{
3911 return __vmalloc_node_range_noprof(size, align, VMALLOC_START, VMALLOC_END,
3912 gfp_mask, PAGE_KERNEL, 0, node, caller);
3913}
3914/*
3915 * This is only for performance analysis of vmalloc and stress purpose.
3916 * It is required by vmalloc test module, therefore do not use it other
3917 * than that.
3918 */
3919#ifdef CONFIG_TEST_VMALLOC_MODULE
3920EXPORT_SYMBOL_GPL(__vmalloc_node_noprof);
3921#endif
3922
3923void *__vmalloc_noprof(unsigned long size, gfp_t gfp_mask)
3924{
3925 return __vmalloc_node_noprof(size, 1, gfp_mask, NUMA_NO_NODE,
3926 __builtin_return_address(0));
3927}
3928EXPORT_SYMBOL(__vmalloc_noprof);
3929
3930/**
3931 * vmalloc - allocate virtually contiguous memory
3932 * @size: allocation size
3933 *
3934 * Allocate enough pages to cover @size from the page level
3935 * allocator and map them into contiguous kernel virtual space.
3936 *
3937 * For tight control over page level allocator and protection flags
3938 * use __vmalloc() instead.
3939 *
3940 * Return: pointer to the allocated memory or %NULL on error
3941 */
3942void *vmalloc_noprof(unsigned long size)
3943{
3944 return __vmalloc_node_noprof(size, 1, GFP_KERNEL, NUMA_NO_NODE,
3945 __builtin_return_address(0));
3946}
3947EXPORT_SYMBOL(vmalloc_noprof);
3948
3949/**
3950 * vmalloc_huge - allocate virtually contiguous memory, allow huge pages
3951 * @size: allocation size
3952 * @gfp_mask: flags for the page level allocator
3953 *
3954 * Allocate enough pages to cover @size from the page level
3955 * allocator and map them into contiguous kernel virtual space.
3956 * If @size is greater than or equal to PMD_SIZE, allow using
3957 * huge pages for the memory
3958 *
3959 * Return: pointer to the allocated memory or %NULL on error
3960 */
3961void *vmalloc_huge_noprof(unsigned long size, gfp_t gfp_mask)
3962{
3963 return __vmalloc_node_range_noprof(size, 1, VMALLOC_START, VMALLOC_END,
3964 gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP,
3965 NUMA_NO_NODE, __builtin_return_address(0));
3966}
3967EXPORT_SYMBOL_GPL(vmalloc_huge_noprof);
3968
3969/**
3970 * vzalloc - allocate virtually contiguous memory with zero fill
3971 * @size: allocation size
3972 *
3973 * Allocate enough pages to cover @size from the page level
3974 * allocator and map them into contiguous kernel virtual space.
3975 * The memory allocated is set to zero.
3976 *
3977 * For tight control over page level allocator and protection flags
3978 * use __vmalloc() instead.
3979 *
3980 * Return: pointer to the allocated memory or %NULL on error
3981 */
3982void *vzalloc_noprof(unsigned long size)
3983{
3984 return __vmalloc_node_noprof(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE,
3985 __builtin_return_address(0));
3986}
3987EXPORT_SYMBOL(vzalloc_noprof);
3988
3989/**
3990 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
3991 * @size: allocation size
3992 *
3993 * The resulting memory area is zeroed so it can be mapped to userspace
3994 * without leaking data.
3995 *
3996 * Return: pointer to the allocated memory or %NULL on error
3997 */
3998void *vmalloc_user_noprof(unsigned long size)
3999{
4000 return __vmalloc_node_range_noprof(size, SHMLBA, VMALLOC_START, VMALLOC_END,
4001 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
4002 VM_USERMAP, NUMA_NO_NODE,
4003 __builtin_return_address(0));
4004}
4005EXPORT_SYMBOL(vmalloc_user_noprof);
4006
4007/**
4008 * vmalloc_node - allocate memory on a specific node
4009 * @size: allocation size
4010 * @node: numa node
4011 *
4012 * Allocate enough pages to cover @size from the page level
4013 * allocator and map them into contiguous kernel virtual space.
4014 *
4015 * For tight control over page level allocator and protection flags
4016 * use __vmalloc() instead.
4017 *
4018 * Return: pointer to the allocated memory or %NULL on error
4019 */
4020void *vmalloc_node_noprof(unsigned long size, int node)
4021{
4022 return __vmalloc_node_noprof(size, 1, GFP_KERNEL, node,
4023 __builtin_return_address(0));
4024}
4025EXPORT_SYMBOL(vmalloc_node_noprof);
4026
4027/**
4028 * vzalloc_node - allocate memory on a specific node with zero fill
4029 * @size: allocation size
4030 * @node: numa node
4031 *
4032 * Allocate enough pages to cover @size from the page level
4033 * allocator and map them into contiguous kernel virtual space.
4034 * The memory allocated is set to zero.
4035 *
4036 * Return: pointer to the allocated memory or %NULL on error
4037 */
4038void *vzalloc_node_noprof(unsigned long size, int node)
4039{
4040 return __vmalloc_node_noprof(size, 1, GFP_KERNEL | __GFP_ZERO, node,
4041 __builtin_return_address(0));
4042}
4043EXPORT_SYMBOL(vzalloc_node_noprof);
4044
4045/**
4046 * vrealloc - reallocate virtually contiguous memory; contents remain unchanged
4047 * @p: object to reallocate memory for
4048 * @size: the size to reallocate
4049 * @flags: the flags for the page level allocator
4050 *
4051 * If @p is %NULL, vrealloc() behaves exactly like vmalloc(). If @size is 0 and
4052 * @p is not a %NULL pointer, the object pointed to is freed.
4053 *
4054 * If __GFP_ZERO logic is requested, callers must ensure that, starting with the
4055 * initial memory allocation, every subsequent call to this API for the same
4056 * memory allocation is flagged with __GFP_ZERO. Otherwise, it is possible that
4057 * __GFP_ZERO is not fully honored by this API.
4058 *
4059 * In any case, the contents of the object pointed to are preserved up to the
4060 * lesser of the new and old sizes.
4061 *
4062 * This function must not be called concurrently with itself or vfree() for the
4063 * same memory allocation.
4064 *
4065 * Return: pointer to the allocated memory; %NULL if @size is zero or in case of
4066 * failure
4067 */
4068void *vrealloc_noprof(const void *p, size_t size, gfp_t flags)
4069{
4070 size_t old_size = 0;
4071 void *n;
4072
4073 if (!size) {
4074 vfree(p);
4075 return NULL;
4076 }
4077
4078 if (p) {
4079 struct vm_struct *vm;
4080
4081 vm = find_vm_area(p);
4082 if (unlikely(!vm)) {
4083 WARN(1, "Trying to vrealloc() nonexistent vm area (%p)\n", p);
4084 return NULL;
4085 }
4086
4087 old_size = get_vm_area_size(vm);
4088 }
4089
4090 /*
4091 * TODO: Shrink the vm_area, i.e. unmap and free unused pages. What
4092 * would be a good heuristic for when to shrink the vm_area?
4093 */
4094 if (size <= old_size) {
4095 /* Zero out spare memory. */
4096 if (want_init_on_alloc(flags))
4097 memset((void *)p + size, 0, old_size - size);
4098 kasan_poison_vmalloc(p + size, old_size - size);
4099 kasan_unpoison_vmalloc(p, size, KASAN_VMALLOC_PROT_NORMAL);
4100 return (void *)p;
4101 }
4102
4103 /* TODO: Grow the vm_area, i.e. allocate and map additional pages. */
4104 n = __vmalloc_noprof(size, flags);
4105 if (!n)
4106 return NULL;
4107
4108 if (p) {
4109 memcpy(n, p, old_size);
4110 vfree(p);
4111 }
4112
4113 return n;
4114}
4115
4116#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
4117#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
4118#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
4119#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
4120#else
4121/*
4122 * 64b systems should always have either DMA or DMA32 zones. For others
4123 * GFP_DMA32 should do the right thing and use the normal zone.
4124 */
4125#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
4126#endif
4127
4128/**
4129 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
4130 * @size: allocation size
4131 *
4132 * Allocate enough 32bit PA addressable pages to cover @size from the
4133 * page level allocator and map them into contiguous kernel virtual space.
4134 *
4135 * Return: pointer to the allocated memory or %NULL on error
4136 */
4137void *vmalloc_32_noprof(unsigned long size)
4138{
4139 return __vmalloc_node_noprof(size, 1, GFP_VMALLOC32, NUMA_NO_NODE,
4140 __builtin_return_address(0));
4141}
4142EXPORT_SYMBOL(vmalloc_32_noprof);
4143
4144/**
4145 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
4146 * @size: allocation size
4147 *
4148 * The resulting memory area is 32bit addressable and zeroed so it can be
4149 * mapped to userspace without leaking data.
4150 *
4151 * Return: pointer to the allocated memory or %NULL on error
4152 */
4153void *vmalloc_32_user_noprof(unsigned long size)
4154{
4155 return __vmalloc_node_range_noprof(size, SHMLBA, VMALLOC_START, VMALLOC_END,
4156 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
4157 VM_USERMAP, NUMA_NO_NODE,
4158 __builtin_return_address(0));
4159}
4160EXPORT_SYMBOL(vmalloc_32_user_noprof);
4161
4162/*
4163 * Atomically zero bytes in the iterator.
4164 *
4165 * Returns the number of zeroed bytes.
4166 */
4167static size_t zero_iter(struct iov_iter *iter, size_t count)
4168{
4169 size_t remains = count;
4170
4171 while (remains > 0) {
4172 size_t num, copied;
4173
4174 num = min_t(size_t, remains, PAGE_SIZE);
4175 copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter);
4176 remains -= copied;
4177
4178 if (copied < num)
4179 break;
4180 }
4181
4182 return count - remains;
4183}
4184
4185/*
4186 * small helper routine, copy contents to iter from addr.
4187 * If the page is not present, fill zero.
4188 *
4189 * Returns the number of copied bytes.
4190 */
4191static size_t aligned_vread_iter(struct iov_iter *iter,
4192 const char *addr, size_t count)
4193{
4194 size_t remains = count;
4195 struct page *page;
4196
4197 while (remains > 0) {
4198 unsigned long offset, length;
4199 size_t copied = 0;
4200
4201 offset = offset_in_page(addr);
4202 length = PAGE_SIZE - offset;
4203 if (length > remains)
4204 length = remains;
4205 page = vmalloc_to_page(addr);
4206 /*
4207 * To do safe access to this _mapped_ area, we need lock. But
4208 * adding lock here means that we need to add overhead of
4209 * vmalloc()/vfree() calls for this _debug_ interface, rarely
4210 * used. Instead of that, we'll use an local mapping via
4211 * copy_page_to_iter_nofault() and accept a small overhead in
4212 * this access function.
4213 */
4214 if (page)
4215 copied = copy_page_to_iter_nofault(page, offset,
4216 length, iter);
4217 else
4218 copied = zero_iter(iter, length);
4219
4220 addr += copied;
4221 remains -= copied;
4222
4223 if (copied != length)
4224 break;
4225 }
4226
4227 return count - remains;
4228}
4229
4230/*
4231 * Read from a vm_map_ram region of memory.
4232 *
4233 * Returns the number of copied bytes.
4234 */
4235static size_t vmap_ram_vread_iter(struct iov_iter *iter, const char *addr,
4236 size_t count, unsigned long flags)
4237{
4238 char *start;
4239 struct vmap_block *vb;
4240 struct xarray *xa;
4241 unsigned long offset;
4242 unsigned int rs, re;
4243 size_t remains, n;
4244
4245 /*
4246 * If it's area created by vm_map_ram() interface directly, but
4247 * not further subdividing and delegating management to vmap_block,
4248 * handle it here.
4249 */
4250 if (!(flags & VMAP_BLOCK))
4251 return aligned_vread_iter(iter, addr, count);
4252
4253 remains = count;
4254
4255 /*
4256 * Area is split into regions and tracked with vmap_block, read out
4257 * each region and zero fill the hole between regions.
4258 */
4259 xa = addr_to_vb_xa((unsigned long) addr);
4260 vb = xa_load(xa, addr_to_vb_idx((unsigned long)addr));
4261 if (!vb)
4262 goto finished_zero;
4263
4264 spin_lock(&vb->lock);
4265 if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) {
4266 spin_unlock(&vb->lock);
4267 goto finished_zero;
4268 }
4269
4270 for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) {
4271 size_t copied;
4272
4273 if (remains == 0)
4274 goto finished;
4275
4276 start = vmap_block_vaddr(vb->va->va_start, rs);
4277
4278 if (addr < start) {
4279 size_t to_zero = min_t(size_t, start - addr, remains);
4280 size_t zeroed = zero_iter(iter, to_zero);
4281
4282 addr += zeroed;
4283 remains -= zeroed;
4284
4285 if (remains == 0 || zeroed != to_zero)
4286 goto finished;
4287 }
4288
4289 /*it could start reading from the middle of used region*/
4290 offset = offset_in_page(addr);
4291 n = ((re - rs + 1) << PAGE_SHIFT) - offset;
4292 if (n > remains)
4293 n = remains;
4294
4295 copied = aligned_vread_iter(iter, start + offset, n);
4296
4297 addr += copied;
4298 remains -= copied;
4299
4300 if (copied != n)
4301 goto finished;
4302 }
4303
4304 spin_unlock(&vb->lock);
4305
4306finished_zero:
4307 /* zero-fill the left dirty or free regions */
4308 return count - remains + zero_iter(iter, remains);
4309finished:
4310 /* We couldn't copy/zero everything */
4311 spin_unlock(&vb->lock);
4312 return count - remains;
4313}
4314
4315/**
4316 * vread_iter() - read vmalloc area in a safe way to an iterator.
4317 * @iter: the iterator to which data should be written.
4318 * @addr: vm address.
4319 * @count: number of bytes to be read.
4320 *
4321 * This function checks that addr is a valid vmalloc'ed area, and
4322 * copy data from that area to a given buffer. If the given memory range
4323 * of [addr...addr+count) includes some valid address, data is copied to
4324 * proper area of @buf. If there are memory holes, they'll be zero-filled.
4325 * IOREMAP area is treated as memory hole and no copy is done.
4326 *
4327 * If [addr...addr+count) doesn't includes any intersects with alive
4328 * vm_struct area, returns 0. @buf should be kernel's buffer.
4329 *
4330 * Note: In usual ops, vread() is never necessary because the caller
4331 * should know vmalloc() area is valid and can use memcpy().
4332 * This is for routines which have to access vmalloc area without
4333 * any information, as /proc/kcore.
4334 *
4335 * Return: number of bytes for which addr and buf should be increased
4336 * (same number as @count) or %0 if [addr...addr+count) doesn't
4337 * include any intersection with valid vmalloc area
4338 */
4339long vread_iter(struct iov_iter *iter, const char *addr, size_t count)
4340{
4341 struct vmap_node *vn;
4342 struct vmap_area *va;
4343 struct vm_struct *vm;
4344 char *vaddr;
4345 size_t n, size, flags, remains;
4346 unsigned long next;
4347
4348 addr = kasan_reset_tag(addr);
4349
4350 /* Don't allow overflow */
4351 if ((unsigned long) addr + count < count)
4352 count = -(unsigned long) addr;
4353
4354 remains = count;
4355
4356 vn = find_vmap_area_exceed_addr_lock((unsigned long) addr, &va);
4357 if (!vn)
4358 goto finished_zero;
4359
4360 /* no intersects with alive vmap_area */
4361 if ((unsigned long)addr + remains <= va->va_start)
4362 goto finished_zero;
4363
4364 do {
4365 size_t copied;
4366
4367 if (remains == 0)
4368 goto finished;
4369
4370 vm = va->vm;
4371 flags = va->flags & VMAP_FLAGS_MASK;
4372 /*
4373 * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need
4374 * be set together with VMAP_RAM.
4375 */
4376 WARN_ON(flags == VMAP_BLOCK);
4377
4378 if (!vm && !flags)
4379 goto next_va;
4380
4381 if (vm && (vm->flags & VM_UNINITIALIZED))
4382 goto next_va;
4383
4384 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
4385 smp_rmb();
4386
4387 vaddr = (char *) va->va_start;
4388 size = vm ? get_vm_area_size(vm) : va_size(va);
4389
4390 if (addr >= vaddr + size)
4391 goto next_va;
4392
4393 if (addr < vaddr) {
4394 size_t to_zero = min_t(size_t, vaddr - addr, remains);
4395 size_t zeroed = zero_iter(iter, to_zero);
4396
4397 addr += zeroed;
4398 remains -= zeroed;
4399
4400 if (remains == 0 || zeroed != to_zero)
4401 goto finished;
4402 }
4403
4404 n = vaddr + size - addr;
4405 if (n > remains)
4406 n = remains;
4407
4408 if (flags & VMAP_RAM)
4409 copied = vmap_ram_vread_iter(iter, addr, n, flags);
4410 else if (!(vm && (vm->flags & (VM_IOREMAP | VM_SPARSE))))
4411 copied = aligned_vread_iter(iter, addr, n);
4412 else /* IOREMAP | SPARSE area is treated as memory hole */
4413 copied = zero_iter(iter, n);
4414
4415 addr += copied;
4416 remains -= copied;
4417
4418 if (copied != n)
4419 goto finished;
4420
4421 next_va:
4422 next = va->va_end;
4423 spin_unlock(&vn->busy.lock);
4424 } while ((vn = find_vmap_area_exceed_addr_lock(next, &va)));
4425
4426finished_zero:
4427 if (vn)
4428 spin_unlock(&vn->busy.lock);
4429
4430 /* zero-fill memory holes */
4431 return count - remains + zero_iter(iter, remains);
4432finished:
4433 /* Nothing remains, or We couldn't copy/zero everything. */
4434 if (vn)
4435 spin_unlock(&vn->busy.lock);
4436
4437 return count - remains;
4438}
4439
4440/**
4441 * remap_vmalloc_range_partial - map vmalloc pages to userspace
4442 * @vma: vma to cover
4443 * @uaddr: target user address to start at
4444 * @kaddr: virtual address of vmalloc kernel memory
4445 * @pgoff: offset from @kaddr to start at
4446 * @size: size of map area
4447 *
4448 * Returns: 0 for success, -Exxx on failure
4449 *
4450 * This function checks that @kaddr is a valid vmalloc'ed area,
4451 * and that it is big enough to cover the range starting at
4452 * @uaddr in @vma. Will return failure if that criteria isn't
4453 * met.
4454 *
4455 * Similar to remap_pfn_range() (see mm/memory.c)
4456 */
4457int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
4458 void *kaddr, unsigned long pgoff,
4459 unsigned long size)
4460{
4461 struct vm_struct *area;
4462 unsigned long off;
4463 unsigned long end_index;
4464
4465 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off))
4466 return -EINVAL;
4467
4468 size = PAGE_ALIGN(size);
4469
4470 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
4471 return -EINVAL;
4472
4473 area = find_vm_area(kaddr);
4474 if (!area)
4475 return -EINVAL;
4476
4477 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
4478 return -EINVAL;
4479
4480 if (check_add_overflow(size, off, &end_index) ||
4481 end_index > get_vm_area_size(area))
4482 return -EINVAL;
4483 kaddr += off;
4484
4485 do {
4486 struct page *page = vmalloc_to_page(kaddr);
4487 int ret;
4488
4489 ret = vm_insert_page(vma, uaddr, page);
4490 if (ret)
4491 return ret;
4492
4493 uaddr += PAGE_SIZE;
4494 kaddr += PAGE_SIZE;
4495 size -= PAGE_SIZE;
4496 } while (size > 0);
4497
4498 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
4499
4500 return 0;
4501}
4502
4503/**
4504 * remap_vmalloc_range - map vmalloc pages to userspace
4505 * @vma: vma to cover (map full range of vma)
4506 * @addr: vmalloc memory
4507 * @pgoff: number of pages into addr before first page to map
4508 *
4509 * Returns: 0 for success, -Exxx on failure
4510 *
4511 * This function checks that addr is a valid vmalloc'ed area, and
4512 * that it is big enough to cover the vma. Will return failure if
4513 * that criteria isn't met.
4514 *
4515 * Similar to remap_pfn_range() (see mm/memory.c)
4516 */
4517int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
4518 unsigned long pgoff)
4519{
4520 return remap_vmalloc_range_partial(vma, vma->vm_start,
4521 addr, pgoff,
4522 vma->vm_end - vma->vm_start);
4523}
4524EXPORT_SYMBOL(remap_vmalloc_range);
4525
4526void free_vm_area(struct vm_struct *area)
4527{
4528 struct vm_struct *ret;
4529 ret = remove_vm_area(area->addr);
4530 BUG_ON(ret != area);
4531 kfree(area);
4532}
4533EXPORT_SYMBOL_GPL(free_vm_area);
4534
4535#ifdef CONFIG_SMP
4536static struct vmap_area *node_to_va(struct rb_node *n)
4537{
4538 return rb_entry_safe(n, struct vmap_area, rb_node);
4539}
4540
4541/**
4542 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
4543 * @addr: target address
4544 *
4545 * Returns: vmap_area if it is found. If there is no such area
4546 * the first highest(reverse order) vmap_area is returned
4547 * i.e. va->va_start < addr && va->va_end < addr or NULL
4548 * if there are no any areas before @addr.
4549 */
4550static struct vmap_area *
4551pvm_find_va_enclose_addr(unsigned long addr)
4552{
4553 struct vmap_area *va, *tmp;
4554 struct rb_node *n;
4555
4556 n = free_vmap_area_root.rb_node;
4557 va = NULL;
4558
4559 while (n) {
4560 tmp = rb_entry(n, struct vmap_area, rb_node);
4561 if (tmp->va_start <= addr) {
4562 va = tmp;
4563 if (tmp->va_end >= addr)
4564 break;
4565
4566 n = n->rb_right;
4567 } else {
4568 n = n->rb_left;
4569 }
4570 }
4571
4572 return va;
4573}
4574
4575/**
4576 * pvm_determine_end_from_reverse - find the highest aligned address
4577 * of free block below VMALLOC_END
4578 * @va:
4579 * in - the VA we start the search(reverse order);
4580 * out - the VA with the highest aligned end address.
4581 * @align: alignment for required highest address
4582 *
4583 * Returns: determined end address within vmap_area
4584 */
4585static unsigned long
4586pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
4587{
4588 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
4589 unsigned long addr;
4590
4591 if (likely(*va)) {
4592 list_for_each_entry_from_reverse((*va),
4593 &free_vmap_area_list, list) {
4594 addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
4595 if ((*va)->va_start < addr)
4596 return addr;
4597 }
4598 }
4599
4600 return 0;
4601}
4602
4603/**
4604 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
4605 * @offsets: array containing offset of each area
4606 * @sizes: array containing size of each area
4607 * @nr_vms: the number of areas to allocate
4608 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
4609 *
4610 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
4611 * vm_structs on success, %NULL on failure
4612 *
4613 * Percpu allocator wants to use congruent vm areas so that it can
4614 * maintain the offsets among percpu areas. This function allocates
4615 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
4616 * be scattered pretty far, distance between two areas easily going up
4617 * to gigabytes. To avoid interacting with regular vmallocs, these
4618 * areas are allocated from top.
4619 *
4620 * Despite its complicated look, this allocator is rather simple. It
4621 * does everything top-down and scans free blocks from the end looking
4622 * for matching base. While scanning, if any of the areas do not fit the
4623 * base address is pulled down to fit the area. Scanning is repeated till
4624 * all the areas fit and then all necessary data structures are inserted
4625 * and the result is returned.
4626 */
4627struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
4628 const size_t *sizes, int nr_vms,
4629 size_t align)
4630{
4631 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
4632 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
4633 struct vmap_area **vas, *va;
4634 struct vm_struct **vms;
4635 int area, area2, last_area, term_area;
4636 unsigned long base, start, size, end, last_end, orig_start, orig_end;
4637 bool purged = false;
4638
4639 /* verify parameters and allocate data structures */
4640 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
4641 for (last_area = 0, area = 0; area < nr_vms; area++) {
4642 start = offsets[area];
4643 end = start + sizes[area];
4644
4645 /* is everything aligned properly? */
4646 BUG_ON(!IS_ALIGNED(offsets[area], align));
4647 BUG_ON(!IS_ALIGNED(sizes[area], align));
4648
4649 /* detect the area with the highest address */
4650 if (start > offsets[last_area])
4651 last_area = area;
4652
4653 for (area2 = area + 1; area2 < nr_vms; area2++) {
4654 unsigned long start2 = offsets[area2];
4655 unsigned long end2 = start2 + sizes[area2];
4656
4657 BUG_ON(start2 < end && start < end2);
4658 }
4659 }
4660 last_end = offsets[last_area] + sizes[last_area];
4661
4662 if (vmalloc_end - vmalloc_start < last_end) {
4663 WARN_ON(true);
4664 return NULL;
4665 }
4666
4667 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
4668 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
4669 if (!vas || !vms)
4670 goto err_free2;
4671
4672 for (area = 0; area < nr_vms; area++) {
4673 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
4674 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
4675 if (!vas[area] || !vms[area])
4676 goto err_free;
4677 }
4678retry:
4679 spin_lock(&free_vmap_area_lock);
4680
4681 /* start scanning - we scan from the top, begin with the last area */
4682 area = term_area = last_area;
4683 start = offsets[area];
4684 end = start + sizes[area];
4685
4686 va = pvm_find_va_enclose_addr(vmalloc_end);
4687 base = pvm_determine_end_from_reverse(&va, align) - end;
4688
4689 while (true) {
4690 /*
4691 * base might have underflowed, add last_end before
4692 * comparing.
4693 */
4694 if (base + last_end < vmalloc_start + last_end)
4695 goto overflow;
4696
4697 /*
4698 * Fitting base has not been found.
4699 */
4700 if (va == NULL)
4701 goto overflow;
4702
4703 /*
4704 * If required width exceeds current VA block, move
4705 * base downwards and then recheck.
4706 */
4707 if (base + end > va->va_end) {
4708 base = pvm_determine_end_from_reverse(&va, align) - end;
4709 term_area = area;
4710 continue;
4711 }
4712
4713 /*
4714 * If this VA does not fit, move base downwards and recheck.
4715 */
4716 if (base + start < va->va_start) {
4717 va = node_to_va(rb_prev(&va->rb_node));
4718 base = pvm_determine_end_from_reverse(&va, align) - end;
4719 term_area = area;
4720 continue;
4721 }
4722
4723 /*
4724 * This area fits, move on to the previous one. If
4725 * the previous one is the terminal one, we're done.
4726 */
4727 area = (area + nr_vms - 1) % nr_vms;
4728 if (area == term_area)
4729 break;
4730
4731 start = offsets[area];
4732 end = start + sizes[area];
4733 va = pvm_find_va_enclose_addr(base + end);
4734 }
4735
4736 /* we've found a fitting base, insert all va's */
4737 for (area = 0; area < nr_vms; area++) {
4738 int ret;
4739
4740 start = base + offsets[area];
4741 size = sizes[area];
4742
4743 va = pvm_find_va_enclose_addr(start);
4744 if (WARN_ON_ONCE(va == NULL))
4745 /* It is a BUG(), but trigger recovery instead. */
4746 goto recovery;
4747
4748 ret = va_clip(&free_vmap_area_root,
4749 &free_vmap_area_list, va, start, size);
4750 if (WARN_ON_ONCE(unlikely(ret)))
4751 /* It is a BUG(), but trigger recovery instead. */
4752 goto recovery;
4753
4754 /* Allocated area. */
4755 va = vas[area];
4756 va->va_start = start;
4757 va->va_end = start + size;
4758 }
4759
4760 spin_unlock(&free_vmap_area_lock);
4761
4762 /* populate the kasan shadow space */
4763 for (area = 0; area < nr_vms; area++) {
4764 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area]))
4765 goto err_free_shadow;
4766 }
4767
4768 /* insert all vm's */
4769 for (area = 0; area < nr_vms; area++) {
4770 struct vmap_node *vn = addr_to_node(vas[area]->va_start);
4771
4772 spin_lock(&vn->busy.lock);
4773 insert_vmap_area(vas[area], &vn->busy.root, &vn->busy.head);
4774 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
4775 pcpu_get_vm_areas);
4776 spin_unlock(&vn->busy.lock);
4777 }
4778
4779 /*
4780 * Mark allocated areas as accessible. Do it now as a best-effort
4781 * approach, as they can be mapped outside of vmalloc code.
4782 * With hardware tag-based KASAN, marking is skipped for
4783 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
4784 */
4785 for (area = 0; area < nr_vms; area++)
4786 vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr,
4787 vms[area]->size, KASAN_VMALLOC_PROT_NORMAL);
4788
4789 kfree(vas);
4790 return vms;
4791
4792recovery:
4793 /*
4794 * Remove previously allocated areas. There is no
4795 * need in removing these areas from the busy tree,
4796 * because they are inserted only on the final step
4797 * and when pcpu_get_vm_areas() is success.
4798 */
4799 while (area--) {
4800 orig_start = vas[area]->va_start;
4801 orig_end = vas[area]->va_end;
4802 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
4803 &free_vmap_area_list);
4804 if (va)
4805 kasan_release_vmalloc(orig_start, orig_end,
4806 va->va_start, va->va_end,
4807 KASAN_VMALLOC_PAGE_RANGE | KASAN_VMALLOC_TLB_FLUSH);
4808 vas[area] = NULL;
4809 }
4810
4811overflow:
4812 spin_unlock(&free_vmap_area_lock);
4813 if (!purged) {
4814 reclaim_and_purge_vmap_areas();
4815 purged = true;
4816
4817 /* Before "retry", check if we recover. */
4818 for (area = 0; area < nr_vms; area++) {
4819 if (vas[area])
4820 continue;
4821
4822 vas[area] = kmem_cache_zalloc(
4823 vmap_area_cachep, GFP_KERNEL);
4824 if (!vas[area])
4825 goto err_free;
4826 }
4827
4828 goto retry;
4829 }
4830
4831err_free:
4832 for (area = 0; area < nr_vms; area++) {
4833 if (vas[area])
4834 kmem_cache_free(vmap_area_cachep, vas[area]);
4835
4836 kfree(vms[area]);
4837 }
4838err_free2:
4839 kfree(vas);
4840 kfree(vms);
4841 return NULL;
4842
4843err_free_shadow:
4844 spin_lock(&free_vmap_area_lock);
4845 /*
4846 * We release all the vmalloc shadows, even the ones for regions that
4847 * hadn't been successfully added. This relies on kasan_release_vmalloc
4848 * being able to tolerate this case.
4849 */
4850 for (area = 0; area < nr_vms; area++) {
4851 orig_start = vas[area]->va_start;
4852 orig_end = vas[area]->va_end;
4853 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
4854 &free_vmap_area_list);
4855 if (va)
4856 kasan_release_vmalloc(orig_start, orig_end,
4857 va->va_start, va->va_end,
4858 KASAN_VMALLOC_PAGE_RANGE | KASAN_VMALLOC_TLB_FLUSH);
4859 vas[area] = NULL;
4860 kfree(vms[area]);
4861 }
4862 spin_unlock(&free_vmap_area_lock);
4863 kfree(vas);
4864 kfree(vms);
4865 return NULL;
4866}
4867
4868/**
4869 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
4870 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
4871 * @nr_vms: the number of allocated areas
4872 *
4873 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
4874 */
4875void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
4876{
4877 int i;
4878
4879 for (i = 0; i < nr_vms; i++)
4880 free_vm_area(vms[i]);
4881 kfree(vms);
4882}
4883#endif /* CONFIG_SMP */
4884
4885#ifdef CONFIG_PRINTK
4886bool vmalloc_dump_obj(void *object)
4887{
4888 const void *caller;
4889 struct vm_struct *vm;
4890 struct vmap_area *va;
4891 struct vmap_node *vn;
4892 unsigned long addr;
4893 unsigned int nr_pages;
4894
4895 addr = PAGE_ALIGN((unsigned long) object);
4896 vn = addr_to_node(addr);
4897
4898 if (!spin_trylock(&vn->busy.lock))
4899 return false;
4900
4901 va = __find_vmap_area(addr, &vn->busy.root);
4902 if (!va || !va->vm) {
4903 spin_unlock(&vn->busy.lock);
4904 return false;
4905 }
4906
4907 vm = va->vm;
4908 addr = (unsigned long) vm->addr;
4909 caller = vm->caller;
4910 nr_pages = vm->nr_pages;
4911 spin_unlock(&vn->busy.lock);
4912
4913 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
4914 nr_pages, addr, caller);
4915
4916 return true;
4917}
4918#endif
4919
4920#ifdef CONFIG_PROC_FS
4921static void show_numa_info(struct seq_file *m, struct vm_struct *v)
4922{
4923 if (IS_ENABLED(CONFIG_NUMA)) {
4924 unsigned int nr, *counters = m->private;
4925 unsigned int step = 1U << vm_area_page_order(v);
4926
4927 if (!counters)
4928 return;
4929
4930 if (v->flags & VM_UNINITIALIZED)
4931 return;
4932 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
4933 smp_rmb();
4934
4935 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
4936
4937 for (nr = 0; nr < v->nr_pages; nr += step)
4938 counters[page_to_nid(v->pages[nr])] += step;
4939 for_each_node_state(nr, N_HIGH_MEMORY)
4940 if (counters[nr])
4941 seq_printf(m, " N%u=%u", nr, counters[nr]);
4942 }
4943}
4944
4945static void show_purge_info(struct seq_file *m)
4946{
4947 struct vmap_node *vn;
4948 struct vmap_area *va;
4949 int i;
4950
4951 for (i = 0; i < nr_vmap_nodes; i++) {
4952 vn = &vmap_nodes[i];
4953
4954 spin_lock(&vn->lazy.lock);
4955 list_for_each_entry(va, &vn->lazy.head, list) {
4956 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
4957 (void *)va->va_start, (void *)va->va_end,
4958 va_size(va));
4959 }
4960 spin_unlock(&vn->lazy.lock);
4961 }
4962}
4963
4964static int vmalloc_info_show(struct seq_file *m, void *p)
4965{
4966 struct vmap_node *vn;
4967 struct vmap_area *va;
4968 struct vm_struct *v;
4969 int i;
4970
4971 for (i = 0; i < nr_vmap_nodes; i++) {
4972 vn = &vmap_nodes[i];
4973
4974 spin_lock(&vn->busy.lock);
4975 list_for_each_entry(va, &vn->busy.head, list) {
4976 if (!va->vm) {
4977 if (va->flags & VMAP_RAM)
4978 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
4979 (void *)va->va_start, (void *)va->va_end,
4980 va_size(va));
4981
4982 continue;
4983 }
4984
4985 v = va->vm;
4986
4987 seq_printf(m, "0x%pK-0x%pK %7ld",
4988 v->addr, v->addr + v->size, v->size);
4989
4990 if (v->caller)
4991 seq_printf(m, " %pS", v->caller);
4992
4993 if (v->nr_pages)
4994 seq_printf(m, " pages=%d", v->nr_pages);
4995
4996 if (v->phys_addr)
4997 seq_printf(m, " phys=%pa", &v->phys_addr);
4998
4999 if (v->flags & VM_IOREMAP)
5000 seq_puts(m, " ioremap");
5001
5002 if (v->flags & VM_SPARSE)
5003 seq_puts(m, " sparse");
5004
5005 if (v->flags & VM_ALLOC)
5006 seq_puts(m, " vmalloc");
5007
5008 if (v->flags & VM_MAP)
5009 seq_puts(m, " vmap");
5010
5011 if (v->flags & VM_USERMAP)
5012 seq_puts(m, " user");
5013
5014 if (v->flags & VM_DMA_COHERENT)
5015 seq_puts(m, " dma-coherent");
5016
5017 if (is_vmalloc_addr(v->pages))
5018 seq_puts(m, " vpages");
5019
5020 show_numa_info(m, v);
5021 seq_putc(m, '\n');
5022 }
5023 spin_unlock(&vn->busy.lock);
5024 }
5025
5026 /*
5027 * As a final step, dump "unpurged" areas.
5028 */
5029 show_purge_info(m);
5030 return 0;
5031}
5032
5033static int __init proc_vmalloc_init(void)
5034{
5035 void *priv_data = NULL;
5036
5037 if (IS_ENABLED(CONFIG_NUMA))
5038 priv_data = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
5039
5040 proc_create_single_data("vmallocinfo",
5041 0400, NULL, vmalloc_info_show, priv_data);
5042
5043 return 0;
5044}
5045module_init(proc_vmalloc_init);
5046
5047#endif
5048
5049static void __init vmap_init_free_space(void)
5050{
5051 unsigned long vmap_start = 1;
5052 const unsigned long vmap_end = ULONG_MAX;
5053 struct vmap_area *free;
5054 struct vm_struct *busy;
5055
5056 /*
5057 * B F B B B F
5058 * -|-----|.....|-----|-----|-----|.....|-
5059 * | The KVA space |
5060 * |<--------------------------------->|
5061 */
5062 for (busy = vmlist; busy; busy = busy->next) {
5063 if ((unsigned long) busy->addr - vmap_start > 0) {
5064 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
5065 if (!WARN_ON_ONCE(!free)) {
5066 free->va_start = vmap_start;
5067 free->va_end = (unsigned long) busy->addr;
5068
5069 insert_vmap_area_augment(free, NULL,
5070 &free_vmap_area_root,
5071 &free_vmap_area_list);
5072 }
5073 }
5074
5075 vmap_start = (unsigned long) busy->addr + busy->size;
5076 }
5077
5078 if (vmap_end - vmap_start > 0) {
5079 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
5080 if (!WARN_ON_ONCE(!free)) {
5081 free->va_start = vmap_start;
5082 free->va_end = vmap_end;
5083
5084 insert_vmap_area_augment(free, NULL,
5085 &free_vmap_area_root,
5086 &free_vmap_area_list);
5087 }
5088 }
5089}
5090
5091static void vmap_init_nodes(void)
5092{
5093 struct vmap_node *vn;
5094 int i, n;
5095
5096#if BITS_PER_LONG == 64
5097 /*
5098 * A high threshold of max nodes is fixed and bound to 128,
5099 * thus a scale factor is 1 for systems where number of cores
5100 * are less or equal to specified threshold.
5101 *
5102 * As for NUMA-aware notes. For bigger systems, for example
5103 * NUMA with multi-sockets, where we can end-up with thousands
5104 * of cores in total, a "sub-numa-clustering" should be added.
5105 *
5106 * In this case a NUMA domain is considered as a single entity
5107 * with dedicated sub-nodes in it which describe one group or
5108 * set of cores. Therefore a per-domain purging is supposed to
5109 * be added as well as a per-domain balancing.
5110 */
5111 n = clamp_t(unsigned int, num_possible_cpus(), 1, 128);
5112
5113 if (n > 1) {
5114 vn = kmalloc_array(n, sizeof(*vn), GFP_NOWAIT | __GFP_NOWARN);
5115 if (vn) {
5116 /* Node partition is 16 pages. */
5117 vmap_zone_size = (1 << 4) * PAGE_SIZE;
5118 nr_vmap_nodes = n;
5119 vmap_nodes = vn;
5120 } else {
5121 pr_err("Failed to allocate an array. Disable a node layer\n");
5122 }
5123 }
5124#endif
5125
5126 for (n = 0; n < nr_vmap_nodes; n++) {
5127 vn = &vmap_nodes[n];
5128 vn->busy.root = RB_ROOT;
5129 INIT_LIST_HEAD(&vn->busy.head);
5130 spin_lock_init(&vn->busy.lock);
5131
5132 vn->lazy.root = RB_ROOT;
5133 INIT_LIST_HEAD(&vn->lazy.head);
5134 spin_lock_init(&vn->lazy.lock);
5135
5136 for (i = 0; i < MAX_VA_SIZE_PAGES; i++) {
5137 INIT_LIST_HEAD(&vn->pool[i].head);
5138 WRITE_ONCE(vn->pool[i].len, 0);
5139 }
5140
5141 spin_lock_init(&vn->pool_lock);
5142 }
5143}
5144
5145static unsigned long
5146vmap_node_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
5147{
5148 unsigned long count;
5149 struct vmap_node *vn;
5150 int i, j;
5151
5152 for (count = 0, i = 0; i < nr_vmap_nodes; i++) {
5153 vn = &vmap_nodes[i];
5154
5155 for (j = 0; j < MAX_VA_SIZE_PAGES; j++)
5156 count += READ_ONCE(vn->pool[j].len);
5157 }
5158
5159 return count ? count : SHRINK_EMPTY;
5160}
5161
5162static unsigned long
5163vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
5164{
5165 int i;
5166
5167 for (i = 0; i < nr_vmap_nodes; i++)
5168 decay_va_pool_node(&vmap_nodes[i], true);
5169
5170 return SHRINK_STOP;
5171}
5172
5173void __init vmalloc_init(void)
5174{
5175 struct shrinker *vmap_node_shrinker;
5176 struct vmap_area *va;
5177 struct vmap_node *vn;
5178 struct vm_struct *tmp;
5179 int i;
5180
5181 /*
5182 * Create the cache for vmap_area objects.
5183 */
5184 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
5185
5186 for_each_possible_cpu(i) {
5187 struct vmap_block_queue *vbq;
5188 struct vfree_deferred *p;
5189
5190 vbq = &per_cpu(vmap_block_queue, i);
5191 spin_lock_init(&vbq->lock);
5192 INIT_LIST_HEAD(&vbq->free);
5193 p = &per_cpu(vfree_deferred, i);
5194 init_llist_head(&p->list);
5195 INIT_WORK(&p->wq, delayed_vfree_work);
5196 xa_init(&vbq->vmap_blocks);
5197 }
5198
5199 /*
5200 * Setup nodes before importing vmlist.
5201 */
5202 vmap_init_nodes();
5203
5204 /* Import existing vmlist entries. */
5205 for (tmp = vmlist; tmp; tmp = tmp->next) {
5206 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
5207 if (WARN_ON_ONCE(!va))
5208 continue;
5209
5210 va->va_start = (unsigned long)tmp->addr;
5211 va->va_end = va->va_start + tmp->size;
5212 va->vm = tmp;
5213
5214 vn = addr_to_node(va->va_start);
5215 insert_vmap_area(va, &vn->busy.root, &vn->busy.head);
5216 }
5217
5218 /*
5219 * Now we can initialize a free vmap space.
5220 */
5221 vmap_init_free_space();
5222 vmap_initialized = true;
5223
5224 vmap_node_shrinker = shrinker_alloc(0, "vmap-node");
5225 if (!vmap_node_shrinker) {
5226 pr_err("Failed to allocate vmap-node shrinker!\n");
5227 return;
5228 }
5229
5230 vmap_node_shrinker->count_objects = vmap_node_shrink_count;
5231 vmap_node_shrinker->scan_objects = vmap_node_shrink_scan;
5232 shrinker_register(vmap_node_shrinker);
5233}