Loading...
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/llist.h>
35#include <linux/bitops.h>
36#include <linux/rbtree_augmented.h>
37#include <linux/overflow.h>
38#include <linux/pgtable.h>
39#include <linux/uaccess.h>
40#include <linux/hugetlb.h>
41#include <asm/tlbflush.h>
42#include <asm/shmparam.h>
43
44#include "internal.h"
45#include "pgalloc-track.h"
46
47#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
48static bool __ro_after_init vmap_allow_huge = true;
49
50static int __init set_nohugevmalloc(char *str)
51{
52 vmap_allow_huge = false;
53 return 0;
54}
55early_param("nohugevmalloc", set_nohugevmalloc);
56#else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
57static const bool vmap_allow_huge = false;
58#endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
59
60bool is_vmalloc_addr(const void *x)
61{
62 unsigned long addr = (unsigned long)x;
63
64 return addr >= VMALLOC_START && addr < VMALLOC_END;
65}
66EXPORT_SYMBOL(is_vmalloc_addr);
67
68struct vfree_deferred {
69 struct llist_head list;
70 struct work_struct wq;
71};
72static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
73
74static void __vunmap(const void *, int);
75
76static void free_work(struct work_struct *w)
77{
78 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
79 struct llist_node *t, *llnode;
80
81 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
82 __vunmap((void *)llnode, 1);
83}
84
85/*** Page table manipulation functions ***/
86static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
87 phys_addr_t phys_addr, pgprot_t prot,
88 unsigned int max_page_shift, pgtbl_mod_mask *mask)
89{
90 pte_t *pte;
91 u64 pfn;
92 unsigned long size = PAGE_SIZE;
93
94 pfn = phys_addr >> PAGE_SHIFT;
95 pte = pte_alloc_kernel_track(pmd, addr, mask);
96 if (!pte)
97 return -ENOMEM;
98 do {
99 BUG_ON(!pte_none(*pte));
100
101#ifdef CONFIG_HUGETLB_PAGE
102 size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
103 if (size != PAGE_SIZE) {
104 pte_t entry = pfn_pte(pfn, prot);
105
106 entry = pte_mkhuge(entry);
107 entry = arch_make_huge_pte(entry, ilog2(size), 0);
108 set_huge_pte_at(&init_mm, addr, pte, entry);
109 pfn += PFN_DOWN(size);
110 continue;
111 }
112#endif
113 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
114 pfn++;
115 } while (pte += PFN_DOWN(size), addr += size, addr != end);
116 *mask |= PGTBL_PTE_MODIFIED;
117 return 0;
118}
119
120static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
121 phys_addr_t phys_addr, pgprot_t prot,
122 unsigned int max_page_shift)
123{
124 if (max_page_shift < PMD_SHIFT)
125 return 0;
126
127 if (!arch_vmap_pmd_supported(prot))
128 return 0;
129
130 if ((end - addr) != PMD_SIZE)
131 return 0;
132
133 if (!IS_ALIGNED(addr, PMD_SIZE))
134 return 0;
135
136 if (!IS_ALIGNED(phys_addr, PMD_SIZE))
137 return 0;
138
139 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
140 return 0;
141
142 return pmd_set_huge(pmd, phys_addr, prot);
143}
144
145static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
146 phys_addr_t phys_addr, pgprot_t prot,
147 unsigned int max_page_shift, pgtbl_mod_mask *mask)
148{
149 pmd_t *pmd;
150 unsigned long next;
151
152 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
153 if (!pmd)
154 return -ENOMEM;
155 do {
156 next = pmd_addr_end(addr, end);
157
158 if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot,
159 max_page_shift)) {
160 *mask |= PGTBL_PMD_MODIFIED;
161 continue;
162 }
163
164 if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask))
165 return -ENOMEM;
166 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
167 return 0;
168}
169
170static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
171 phys_addr_t phys_addr, pgprot_t prot,
172 unsigned int max_page_shift)
173{
174 if (max_page_shift < PUD_SHIFT)
175 return 0;
176
177 if (!arch_vmap_pud_supported(prot))
178 return 0;
179
180 if ((end - addr) != PUD_SIZE)
181 return 0;
182
183 if (!IS_ALIGNED(addr, PUD_SIZE))
184 return 0;
185
186 if (!IS_ALIGNED(phys_addr, PUD_SIZE))
187 return 0;
188
189 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
190 return 0;
191
192 return pud_set_huge(pud, phys_addr, prot);
193}
194
195static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
196 phys_addr_t phys_addr, pgprot_t prot,
197 unsigned int max_page_shift, pgtbl_mod_mask *mask)
198{
199 pud_t *pud;
200 unsigned long next;
201
202 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
203 if (!pud)
204 return -ENOMEM;
205 do {
206 next = pud_addr_end(addr, end);
207
208 if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot,
209 max_page_shift)) {
210 *mask |= PGTBL_PUD_MODIFIED;
211 continue;
212 }
213
214 if (vmap_pmd_range(pud, addr, next, phys_addr, prot,
215 max_page_shift, mask))
216 return -ENOMEM;
217 } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
218 return 0;
219}
220
221static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
222 phys_addr_t phys_addr, pgprot_t prot,
223 unsigned int max_page_shift)
224{
225 if (max_page_shift < P4D_SHIFT)
226 return 0;
227
228 if (!arch_vmap_p4d_supported(prot))
229 return 0;
230
231 if ((end - addr) != P4D_SIZE)
232 return 0;
233
234 if (!IS_ALIGNED(addr, P4D_SIZE))
235 return 0;
236
237 if (!IS_ALIGNED(phys_addr, P4D_SIZE))
238 return 0;
239
240 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
241 return 0;
242
243 return p4d_set_huge(p4d, phys_addr, prot);
244}
245
246static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
247 phys_addr_t phys_addr, pgprot_t prot,
248 unsigned int max_page_shift, pgtbl_mod_mask *mask)
249{
250 p4d_t *p4d;
251 unsigned long next;
252
253 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
254 if (!p4d)
255 return -ENOMEM;
256 do {
257 next = p4d_addr_end(addr, end);
258
259 if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot,
260 max_page_shift)) {
261 *mask |= PGTBL_P4D_MODIFIED;
262 continue;
263 }
264
265 if (vmap_pud_range(p4d, addr, next, phys_addr, prot,
266 max_page_shift, mask))
267 return -ENOMEM;
268 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
269 return 0;
270}
271
272static int vmap_range_noflush(unsigned long addr, unsigned long end,
273 phys_addr_t phys_addr, pgprot_t prot,
274 unsigned int max_page_shift)
275{
276 pgd_t *pgd;
277 unsigned long start;
278 unsigned long next;
279 int err;
280 pgtbl_mod_mask mask = 0;
281
282 might_sleep();
283 BUG_ON(addr >= end);
284
285 start = addr;
286 pgd = pgd_offset_k(addr);
287 do {
288 next = pgd_addr_end(addr, end);
289 err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
290 max_page_shift, &mask);
291 if (err)
292 break;
293 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
294
295 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
296 arch_sync_kernel_mappings(start, end);
297
298 return err;
299}
300
301int vmap_range(unsigned long addr, unsigned long end,
302 phys_addr_t phys_addr, pgprot_t prot,
303 unsigned int max_page_shift)
304{
305 int err;
306
307 err = vmap_range_noflush(addr, end, phys_addr, prot, max_page_shift);
308 flush_cache_vmap(addr, end);
309
310 return err;
311}
312
313static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
314 pgtbl_mod_mask *mask)
315{
316 pte_t *pte;
317
318 pte = pte_offset_kernel(pmd, addr);
319 do {
320 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
321 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
322 } while (pte++, addr += PAGE_SIZE, addr != end);
323 *mask |= PGTBL_PTE_MODIFIED;
324}
325
326static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
327 pgtbl_mod_mask *mask)
328{
329 pmd_t *pmd;
330 unsigned long next;
331 int cleared;
332
333 pmd = pmd_offset(pud, addr);
334 do {
335 next = pmd_addr_end(addr, end);
336
337 cleared = pmd_clear_huge(pmd);
338 if (cleared || pmd_bad(*pmd))
339 *mask |= PGTBL_PMD_MODIFIED;
340
341 if (cleared)
342 continue;
343 if (pmd_none_or_clear_bad(pmd))
344 continue;
345 vunmap_pte_range(pmd, addr, next, mask);
346
347 cond_resched();
348 } while (pmd++, addr = next, addr != end);
349}
350
351static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
352 pgtbl_mod_mask *mask)
353{
354 pud_t *pud;
355 unsigned long next;
356 int cleared;
357
358 pud = pud_offset(p4d, addr);
359 do {
360 next = pud_addr_end(addr, end);
361
362 cleared = pud_clear_huge(pud);
363 if (cleared || pud_bad(*pud))
364 *mask |= PGTBL_PUD_MODIFIED;
365
366 if (cleared)
367 continue;
368 if (pud_none_or_clear_bad(pud))
369 continue;
370 vunmap_pmd_range(pud, addr, next, mask);
371 } while (pud++, addr = next, addr != end);
372}
373
374static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
375 pgtbl_mod_mask *mask)
376{
377 p4d_t *p4d;
378 unsigned long next;
379 int cleared;
380
381 p4d = p4d_offset(pgd, addr);
382 do {
383 next = p4d_addr_end(addr, end);
384
385 cleared = p4d_clear_huge(p4d);
386 if (cleared || p4d_bad(*p4d))
387 *mask |= PGTBL_P4D_MODIFIED;
388
389 if (cleared)
390 continue;
391 if (p4d_none_or_clear_bad(p4d))
392 continue;
393 vunmap_pud_range(p4d, addr, next, mask);
394 } while (p4d++, addr = next, addr != end);
395}
396
397/*
398 * vunmap_range_noflush is similar to vunmap_range, but does not
399 * flush caches or TLBs.
400 *
401 * The caller is responsible for calling flush_cache_vmap() before calling
402 * this function, and flush_tlb_kernel_range after it has returned
403 * successfully (and before the addresses are expected to cause a page fault
404 * or be re-mapped for something else, if TLB flushes are being delayed or
405 * coalesced).
406 *
407 * This is an internal function only. Do not use outside mm/.
408 */
409void vunmap_range_noflush(unsigned long start, unsigned long end)
410{
411 unsigned long next;
412 pgd_t *pgd;
413 unsigned long addr = start;
414 pgtbl_mod_mask mask = 0;
415
416 BUG_ON(addr >= end);
417 pgd = pgd_offset_k(addr);
418 do {
419 next = pgd_addr_end(addr, end);
420 if (pgd_bad(*pgd))
421 mask |= PGTBL_PGD_MODIFIED;
422 if (pgd_none_or_clear_bad(pgd))
423 continue;
424 vunmap_p4d_range(pgd, addr, next, &mask);
425 } while (pgd++, addr = next, addr != end);
426
427 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
428 arch_sync_kernel_mappings(start, end);
429}
430
431/**
432 * vunmap_range - unmap kernel virtual addresses
433 * @addr: start of the VM area to unmap
434 * @end: end of the VM area to unmap (non-inclusive)
435 *
436 * Clears any present PTEs in the virtual address range, flushes TLBs and
437 * caches. Any subsequent access to the address before it has been re-mapped
438 * is a kernel bug.
439 */
440void vunmap_range(unsigned long addr, unsigned long end)
441{
442 flush_cache_vunmap(addr, end);
443 vunmap_range_noflush(addr, end);
444 flush_tlb_kernel_range(addr, end);
445}
446
447static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
448 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
449 pgtbl_mod_mask *mask)
450{
451 pte_t *pte;
452
453 /*
454 * nr is a running index into the array which helps higher level
455 * callers keep track of where we're up to.
456 */
457
458 pte = pte_alloc_kernel_track(pmd, addr, mask);
459 if (!pte)
460 return -ENOMEM;
461 do {
462 struct page *page = pages[*nr];
463
464 if (WARN_ON(!pte_none(*pte)))
465 return -EBUSY;
466 if (WARN_ON(!page))
467 return -ENOMEM;
468 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
469 (*nr)++;
470 } while (pte++, addr += PAGE_SIZE, addr != end);
471 *mask |= PGTBL_PTE_MODIFIED;
472 return 0;
473}
474
475static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr,
476 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
477 pgtbl_mod_mask *mask)
478{
479 pmd_t *pmd;
480 unsigned long next;
481
482 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
483 if (!pmd)
484 return -ENOMEM;
485 do {
486 next = pmd_addr_end(addr, end);
487 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask))
488 return -ENOMEM;
489 } while (pmd++, addr = next, addr != end);
490 return 0;
491}
492
493static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr,
494 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
495 pgtbl_mod_mask *mask)
496{
497 pud_t *pud;
498 unsigned long next;
499
500 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
501 if (!pud)
502 return -ENOMEM;
503 do {
504 next = pud_addr_end(addr, end);
505 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask))
506 return -ENOMEM;
507 } while (pud++, addr = next, addr != end);
508 return 0;
509}
510
511static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr,
512 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
513 pgtbl_mod_mask *mask)
514{
515 p4d_t *p4d;
516 unsigned long next;
517
518 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
519 if (!p4d)
520 return -ENOMEM;
521 do {
522 next = p4d_addr_end(addr, end);
523 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask))
524 return -ENOMEM;
525 } while (p4d++, addr = next, addr != end);
526 return 0;
527}
528
529static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
530 pgprot_t prot, struct page **pages)
531{
532 unsigned long start = addr;
533 pgd_t *pgd;
534 unsigned long next;
535 int err = 0;
536 int nr = 0;
537 pgtbl_mod_mask mask = 0;
538
539 BUG_ON(addr >= end);
540 pgd = pgd_offset_k(addr);
541 do {
542 next = pgd_addr_end(addr, end);
543 if (pgd_bad(*pgd))
544 mask |= PGTBL_PGD_MODIFIED;
545 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
546 if (err)
547 return err;
548 } while (pgd++, addr = next, addr != end);
549
550 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
551 arch_sync_kernel_mappings(start, end);
552
553 return 0;
554}
555
556/*
557 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
558 * flush caches.
559 *
560 * The caller is responsible for calling flush_cache_vmap() after this
561 * function returns successfully and before the addresses are accessed.
562 *
563 * This is an internal function only. Do not use outside mm/.
564 */
565int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
566 pgprot_t prot, struct page **pages, unsigned int page_shift)
567{
568 unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
569
570 WARN_ON(page_shift < PAGE_SHIFT);
571
572 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
573 page_shift == PAGE_SHIFT)
574 return vmap_small_pages_range_noflush(addr, end, prot, pages);
575
576 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
577 int err;
578
579 err = vmap_range_noflush(addr, addr + (1UL << page_shift),
580 __pa(page_address(pages[i])), prot,
581 page_shift);
582 if (err)
583 return err;
584
585 addr += 1UL << page_shift;
586 }
587
588 return 0;
589}
590
591/**
592 * vmap_pages_range - map pages to a kernel virtual address
593 * @addr: start of the VM area to map
594 * @end: end of the VM area to map (non-inclusive)
595 * @prot: page protection flags to use
596 * @pages: pages to map (always PAGE_SIZE pages)
597 * @page_shift: maximum shift that the pages may be mapped with, @pages must
598 * be aligned and contiguous up to at least this shift.
599 *
600 * RETURNS:
601 * 0 on success, -errno on failure.
602 */
603static int vmap_pages_range(unsigned long addr, unsigned long end,
604 pgprot_t prot, struct page **pages, unsigned int page_shift)
605{
606 int err;
607
608 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
609 flush_cache_vmap(addr, end);
610 return err;
611}
612
613int is_vmalloc_or_module_addr(const void *x)
614{
615 /*
616 * ARM, x86-64 and sparc64 put modules in a special place,
617 * and fall back on vmalloc() if that fails. Others
618 * just put it in the vmalloc space.
619 */
620#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
621 unsigned long addr = (unsigned long)x;
622 if (addr >= MODULES_VADDR && addr < MODULES_END)
623 return 1;
624#endif
625 return is_vmalloc_addr(x);
626}
627
628/*
629 * Walk a vmap address to the struct page it maps. Huge vmap mappings will
630 * return the tail page that corresponds to the base page address, which
631 * matches small vmap mappings.
632 */
633struct page *vmalloc_to_page(const void *vmalloc_addr)
634{
635 unsigned long addr = (unsigned long) vmalloc_addr;
636 struct page *page = NULL;
637 pgd_t *pgd = pgd_offset_k(addr);
638 p4d_t *p4d;
639 pud_t *pud;
640 pmd_t *pmd;
641 pte_t *ptep, pte;
642
643 /*
644 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
645 * architectures that do not vmalloc module space
646 */
647 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
648
649 if (pgd_none(*pgd))
650 return NULL;
651 if (WARN_ON_ONCE(pgd_leaf(*pgd)))
652 return NULL; /* XXX: no allowance for huge pgd */
653 if (WARN_ON_ONCE(pgd_bad(*pgd)))
654 return NULL;
655
656 p4d = p4d_offset(pgd, addr);
657 if (p4d_none(*p4d))
658 return NULL;
659 if (p4d_leaf(*p4d))
660 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
661 if (WARN_ON_ONCE(p4d_bad(*p4d)))
662 return NULL;
663
664 pud = pud_offset(p4d, addr);
665 if (pud_none(*pud))
666 return NULL;
667 if (pud_leaf(*pud))
668 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
669 if (WARN_ON_ONCE(pud_bad(*pud)))
670 return NULL;
671
672 pmd = pmd_offset(pud, addr);
673 if (pmd_none(*pmd))
674 return NULL;
675 if (pmd_leaf(*pmd))
676 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
677 if (WARN_ON_ONCE(pmd_bad(*pmd)))
678 return NULL;
679
680 ptep = pte_offset_map(pmd, addr);
681 pte = *ptep;
682 if (pte_present(pte))
683 page = pte_page(pte);
684 pte_unmap(ptep);
685
686 return page;
687}
688EXPORT_SYMBOL(vmalloc_to_page);
689
690/*
691 * Map a vmalloc()-space virtual address to the physical page frame number.
692 */
693unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
694{
695 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
696}
697EXPORT_SYMBOL(vmalloc_to_pfn);
698
699
700/*** Global kva allocator ***/
701
702#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
703#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
704
705
706static DEFINE_SPINLOCK(vmap_area_lock);
707static DEFINE_SPINLOCK(free_vmap_area_lock);
708/* Export for kexec only */
709LIST_HEAD(vmap_area_list);
710static struct rb_root vmap_area_root = RB_ROOT;
711static bool vmap_initialized __read_mostly;
712
713static struct rb_root purge_vmap_area_root = RB_ROOT;
714static LIST_HEAD(purge_vmap_area_list);
715static DEFINE_SPINLOCK(purge_vmap_area_lock);
716
717/*
718 * This kmem_cache is used for vmap_area objects. Instead of
719 * allocating from slab we reuse an object from this cache to
720 * make things faster. Especially in "no edge" splitting of
721 * free block.
722 */
723static struct kmem_cache *vmap_area_cachep;
724
725/*
726 * This linked list is used in pair with free_vmap_area_root.
727 * It gives O(1) access to prev/next to perform fast coalescing.
728 */
729static LIST_HEAD(free_vmap_area_list);
730
731/*
732 * This augment red-black tree represents the free vmap space.
733 * All vmap_area objects in this tree are sorted by va->va_start
734 * address. It is used for allocation and merging when a vmap
735 * object is released.
736 *
737 * Each vmap_area node contains a maximum available free block
738 * of its sub-tree, right or left. Therefore it is possible to
739 * find a lowest match of free area.
740 */
741static struct rb_root free_vmap_area_root = RB_ROOT;
742
743/*
744 * Preload a CPU with one object for "no edge" split case. The
745 * aim is to get rid of allocations from the atomic context, thus
746 * to use more permissive allocation masks.
747 */
748static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
749
750static __always_inline unsigned long
751va_size(struct vmap_area *va)
752{
753 return (va->va_end - va->va_start);
754}
755
756static __always_inline unsigned long
757get_subtree_max_size(struct rb_node *node)
758{
759 struct vmap_area *va;
760
761 va = rb_entry_safe(node, struct vmap_area, rb_node);
762 return va ? va->subtree_max_size : 0;
763}
764
765/*
766 * Gets called when remove the node and rotate.
767 */
768static __always_inline unsigned long
769compute_subtree_max_size(struct vmap_area *va)
770{
771 return max3(va_size(va),
772 get_subtree_max_size(va->rb_node.rb_left),
773 get_subtree_max_size(va->rb_node.rb_right));
774}
775
776RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
777 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
778
779static void purge_vmap_area_lazy(void);
780static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
781static unsigned long lazy_max_pages(void);
782
783static atomic_long_t nr_vmalloc_pages;
784
785unsigned long vmalloc_nr_pages(void)
786{
787 return atomic_long_read(&nr_vmalloc_pages);
788}
789
790static struct vmap_area *__find_vmap_area(unsigned long addr)
791{
792 struct rb_node *n = vmap_area_root.rb_node;
793
794 while (n) {
795 struct vmap_area *va;
796
797 va = rb_entry(n, struct vmap_area, rb_node);
798 if (addr < va->va_start)
799 n = n->rb_left;
800 else if (addr >= va->va_end)
801 n = n->rb_right;
802 else
803 return va;
804 }
805
806 return NULL;
807}
808
809/*
810 * This function returns back addresses of parent node
811 * and its left or right link for further processing.
812 *
813 * Otherwise NULL is returned. In that case all further
814 * steps regarding inserting of conflicting overlap range
815 * have to be declined and actually considered as a bug.
816 */
817static __always_inline struct rb_node **
818find_va_links(struct vmap_area *va,
819 struct rb_root *root, struct rb_node *from,
820 struct rb_node **parent)
821{
822 struct vmap_area *tmp_va;
823 struct rb_node **link;
824
825 if (root) {
826 link = &root->rb_node;
827 if (unlikely(!*link)) {
828 *parent = NULL;
829 return link;
830 }
831 } else {
832 link = &from;
833 }
834
835 /*
836 * Go to the bottom of the tree. When we hit the last point
837 * we end up with parent rb_node and correct direction, i name
838 * it link, where the new va->rb_node will be attached to.
839 */
840 do {
841 tmp_va = rb_entry(*link, struct vmap_area, rb_node);
842
843 /*
844 * During the traversal we also do some sanity check.
845 * Trigger the BUG() if there are sides(left/right)
846 * or full overlaps.
847 */
848 if (va->va_start < tmp_va->va_end &&
849 va->va_end <= tmp_va->va_start)
850 link = &(*link)->rb_left;
851 else if (va->va_end > tmp_va->va_start &&
852 va->va_start >= tmp_va->va_end)
853 link = &(*link)->rb_right;
854 else {
855 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
856 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
857
858 return NULL;
859 }
860 } while (*link);
861
862 *parent = &tmp_va->rb_node;
863 return link;
864}
865
866static __always_inline struct list_head *
867get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
868{
869 struct list_head *list;
870
871 if (unlikely(!parent))
872 /*
873 * The red-black tree where we try to find VA neighbors
874 * before merging or inserting is empty, i.e. it means
875 * there is no free vmap space. Normally it does not
876 * happen but we handle this case anyway.
877 */
878 return NULL;
879
880 list = &rb_entry(parent, struct vmap_area, rb_node)->list;
881 return (&parent->rb_right == link ? list->next : list);
882}
883
884static __always_inline void
885link_va(struct vmap_area *va, struct rb_root *root,
886 struct rb_node *parent, struct rb_node **link, struct list_head *head)
887{
888 /*
889 * VA is still not in the list, but we can
890 * identify its future previous list_head node.
891 */
892 if (likely(parent)) {
893 head = &rb_entry(parent, struct vmap_area, rb_node)->list;
894 if (&parent->rb_right != link)
895 head = head->prev;
896 }
897
898 /* Insert to the rb-tree */
899 rb_link_node(&va->rb_node, parent, link);
900 if (root == &free_vmap_area_root) {
901 /*
902 * Some explanation here. Just perform simple insertion
903 * to the tree. We do not set va->subtree_max_size to
904 * its current size before calling rb_insert_augmented().
905 * It is because of we populate the tree from the bottom
906 * to parent levels when the node _is_ in the tree.
907 *
908 * Therefore we set subtree_max_size to zero after insertion,
909 * to let __augment_tree_propagate_from() puts everything to
910 * the correct order later on.
911 */
912 rb_insert_augmented(&va->rb_node,
913 root, &free_vmap_area_rb_augment_cb);
914 va->subtree_max_size = 0;
915 } else {
916 rb_insert_color(&va->rb_node, root);
917 }
918
919 /* Address-sort this list */
920 list_add(&va->list, head);
921}
922
923static __always_inline void
924unlink_va(struct vmap_area *va, struct rb_root *root)
925{
926 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
927 return;
928
929 if (root == &free_vmap_area_root)
930 rb_erase_augmented(&va->rb_node,
931 root, &free_vmap_area_rb_augment_cb);
932 else
933 rb_erase(&va->rb_node, root);
934
935 list_del(&va->list);
936 RB_CLEAR_NODE(&va->rb_node);
937}
938
939#if DEBUG_AUGMENT_PROPAGATE_CHECK
940static void
941augment_tree_propagate_check(void)
942{
943 struct vmap_area *va;
944 unsigned long computed_size;
945
946 list_for_each_entry(va, &free_vmap_area_list, list) {
947 computed_size = compute_subtree_max_size(va);
948 if (computed_size != va->subtree_max_size)
949 pr_emerg("tree is corrupted: %lu, %lu\n",
950 va_size(va), va->subtree_max_size);
951 }
952}
953#endif
954
955/*
956 * This function populates subtree_max_size from bottom to upper
957 * levels starting from VA point. The propagation must be done
958 * when VA size is modified by changing its va_start/va_end. Or
959 * in case of newly inserting of VA to the tree.
960 *
961 * It means that __augment_tree_propagate_from() must be called:
962 * - After VA has been inserted to the tree(free path);
963 * - After VA has been shrunk(allocation path);
964 * - After VA has been increased(merging path).
965 *
966 * Please note that, it does not mean that upper parent nodes
967 * and their subtree_max_size are recalculated all the time up
968 * to the root node.
969 *
970 * 4--8
971 * /\
972 * / \
973 * / \
974 * 2--2 8--8
975 *
976 * For example if we modify the node 4, shrinking it to 2, then
977 * no any modification is required. If we shrink the node 2 to 1
978 * its subtree_max_size is updated only, and set to 1. If we shrink
979 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
980 * node becomes 4--6.
981 */
982static __always_inline void
983augment_tree_propagate_from(struct vmap_area *va)
984{
985 /*
986 * Populate the tree from bottom towards the root until
987 * the calculated maximum available size of checked node
988 * is equal to its current one.
989 */
990 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL);
991
992#if DEBUG_AUGMENT_PROPAGATE_CHECK
993 augment_tree_propagate_check();
994#endif
995}
996
997static void
998insert_vmap_area(struct vmap_area *va,
999 struct rb_root *root, struct list_head *head)
1000{
1001 struct rb_node **link;
1002 struct rb_node *parent;
1003
1004 link = find_va_links(va, root, NULL, &parent);
1005 if (link)
1006 link_va(va, root, parent, link, head);
1007}
1008
1009static void
1010insert_vmap_area_augment(struct vmap_area *va,
1011 struct rb_node *from, struct rb_root *root,
1012 struct list_head *head)
1013{
1014 struct rb_node **link;
1015 struct rb_node *parent;
1016
1017 if (from)
1018 link = find_va_links(va, NULL, from, &parent);
1019 else
1020 link = find_va_links(va, root, NULL, &parent);
1021
1022 if (link) {
1023 link_va(va, root, parent, link, head);
1024 augment_tree_propagate_from(va);
1025 }
1026}
1027
1028/*
1029 * Merge de-allocated chunk of VA memory with previous
1030 * and next free blocks. If coalesce is not done a new
1031 * free area is inserted. If VA has been merged, it is
1032 * freed.
1033 *
1034 * Please note, it can return NULL in case of overlap
1035 * ranges, followed by WARN() report. Despite it is a
1036 * buggy behaviour, a system can be alive and keep
1037 * ongoing.
1038 */
1039static __always_inline struct vmap_area *
1040merge_or_add_vmap_area(struct vmap_area *va,
1041 struct rb_root *root, struct list_head *head)
1042{
1043 struct vmap_area *sibling;
1044 struct list_head *next;
1045 struct rb_node **link;
1046 struct rb_node *parent;
1047 bool merged = false;
1048
1049 /*
1050 * Find a place in the tree where VA potentially will be
1051 * inserted, unless it is merged with its sibling/siblings.
1052 */
1053 link = find_va_links(va, root, NULL, &parent);
1054 if (!link)
1055 return NULL;
1056
1057 /*
1058 * Get next node of VA to check if merging can be done.
1059 */
1060 next = get_va_next_sibling(parent, link);
1061 if (unlikely(next == NULL))
1062 goto insert;
1063
1064 /*
1065 * start end
1066 * | |
1067 * |<------VA------>|<-----Next----->|
1068 * | |
1069 * start end
1070 */
1071 if (next != head) {
1072 sibling = list_entry(next, struct vmap_area, list);
1073 if (sibling->va_start == va->va_end) {
1074 sibling->va_start = va->va_start;
1075
1076 /* Free vmap_area object. */
1077 kmem_cache_free(vmap_area_cachep, va);
1078
1079 /* Point to the new merged area. */
1080 va = sibling;
1081 merged = true;
1082 }
1083 }
1084
1085 /*
1086 * start end
1087 * | |
1088 * |<-----Prev----->|<------VA------>|
1089 * | |
1090 * start end
1091 */
1092 if (next->prev != head) {
1093 sibling = list_entry(next->prev, struct vmap_area, list);
1094 if (sibling->va_end == va->va_start) {
1095 /*
1096 * If both neighbors are coalesced, it is important
1097 * to unlink the "next" node first, followed by merging
1098 * with "previous" one. Otherwise the tree might not be
1099 * fully populated if a sibling's augmented value is
1100 * "normalized" because of rotation operations.
1101 */
1102 if (merged)
1103 unlink_va(va, root);
1104
1105 sibling->va_end = va->va_end;
1106
1107 /* Free vmap_area object. */
1108 kmem_cache_free(vmap_area_cachep, va);
1109
1110 /* Point to the new merged area. */
1111 va = sibling;
1112 merged = true;
1113 }
1114 }
1115
1116insert:
1117 if (!merged)
1118 link_va(va, root, parent, link, head);
1119
1120 return va;
1121}
1122
1123static __always_inline struct vmap_area *
1124merge_or_add_vmap_area_augment(struct vmap_area *va,
1125 struct rb_root *root, struct list_head *head)
1126{
1127 va = merge_or_add_vmap_area(va, root, head);
1128 if (va)
1129 augment_tree_propagate_from(va);
1130
1131 return va;
1132}
1133
1134static __always_inline bool
1135is_within_this_va(struct vmap_area *va, unsigned long size,
1136 unsigned long align, unsigned long vstart)
1137{
1138 unsigned long nva_start_addr;
1139
1140 if (va->va_start > vstart)
1141 nva_start_addr = ALIGN(va->va_start, align);
1142 else
1143 nva_start_addr = ALIGN(vstart, align);
1144
1145 /* Can be overflowed due to big size or alignment. */
1146 if (nva_start_addr + size < nva_start_addr ||
1147 nva_start_addr < vstart)
1148 return false;
1149
1150 return (nva_start_addr + size <= va->va_end);
1151}
1152
1153/*
1154 * Find the first free block(lowest start address) in the tree,
1155 * that will accomplish the request corresponding to passing
1156 * parameters.
1157 */
1158static __always_inline struct vmap_area *
1159find_vmap_lowest_match(unsigned long size,
1160 unsigned long align, unsigned long vstart)
1161{
1162 struct vmap_area *va;
1163 struct rb_node *node;
1164 unsigned long length;
1165
1166 /* Start from the root. */
1167 node = free_vmap_area_root.rb_node;
1168
1169 /* Adjust the search size for alignment overhead. */
1170 length = size + align - 1;
1171
1172 while (node) {
1173 va = rb_entry(node, struct vmap_area, rb_node);
1174
1175 if (get_subtree_max_size(node->rb_left) >= length &&
1176 vstart < va->va_start) {
1177 node = node->rb_left;
1178 } else {
1179 if (is_within_this_va(va, size, align, vstart))
1180 return va;
1181
1182 /*
1183 * Does not make sense to go deeper towards the right
1184 * sub-tree if it does not have a free block that is
1185 * equal or bigger to the requested search length.
1186 */
1187 if (get_subtree_max_size(node->rb_right) >= length) {
1188 node = node->rb_right;
1189 continue;
1190 }
1191
1192 /*
1193 * OK. We roll back and find the first right sub-tree,
1194 * that will satisfy the search criteria. It can happen
1195 * only once due to "vstart" restriction.
1196 */
1197 while ((node = rb_parent(node))) {
1198 va = rb_entry(node, struct vmap_area, rb_node);
1199 if (is_within_this_va(va, size, align, vstart))
1200 return va;
1201
1202 if (get_subtree_max_size(node->rb_right) >= length &&
1203 vstart <= va->va_start) {
1204 node = node->rb_right;
1205 break;
1206 }
1207 }
1208 }
1209 }
1210
1211 return NULL;
1212}
1213
1214#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1215#include <linux/random.h>
1216
1217static struct vmap_area *
1218find_vmap_lowest_linear_match(unsigned long size,
1219 unsigned long align, unsigned long vstart)
1220{
1221 struct vmap_area *va;
1222
1223 list_for_each_entry(va, &free_vmap_area_list, list) {
1224 if (!is_within_this_va(va, size, align, vstart))
1225 continue;
1226
1227 return va;
1228 }
1229
1230 return NULL;
1231}
1232
1233static void
1234find_vmap_lowest_match_check(unsigned long size)
1235{
1236 struct vmap_area *va_1, *va_2;
1237 unsigned long vstart;
1238 unsigned int rnd;
1239
1240 get_random_bytes(&rnd, sizeof(rnd));
1241 vstart = VMALLOC_START + rnd;
1242
1243 va_1 = find_vmap_lowest_match(size, 1, vstart);
1244 va_2 = find_vmap_lowest_linear_match(size, 1, vstart);
1245
1246 if (va_1 != va_2)
1247 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
1248 va_1, va_2, vstart);
1249}
1250#endif
1251
1252enum fit_type {
1253 NOTHING_FIT = 0,
1254 FL_FIT_TYPE = 1, /* full fit */
1255 LE_FIT_TYPE = 2, /* left edge fit */
1256 RE_FIT_TYPE = 3, /* right edge fit */
1257 NE_FIT_TYPE = 4 /* no edge fit */
1258};
1259
1260static __always_inline enum fit_type
1261classify_va_fit_type(struct vmap_area *va,
1262 unsigned long nva_start_addr, unsigned long size)
1263{
1264 enum fit_type type;
1265
1266 /* Check if it is within VA. */
1267 if (nva_start_addr < va->va_start ||
1268 nva_start_addr + size > va->va_end)
1269 return NOTHING_FIT;
1270
1271 /* Now classify. */
1272 if (va->va_start == nva_start_addr) {
1273 if (va->va_end == nva_start_addr + size)
1274 type = FL_FIT_TYPE;
1275 else
1276 type = LE_FIT_TYPE;
1277 } else if (va->va_end == nva_start_addr + size) {
1278 type = RE_FIT_TYPE;
1279 } else {
1280 type = NE_FIT_TYPE;
1281 }
1282
1283 return type;
1284}
1285
1286static __always_inline int
1287adjust_va_to_fit_type(struct vmap_area *va,
1288 unsigned long nva_start_addr, unsigned long size,
1289 enum fit_type type)
1290{
1291 struct vmap_area *lva = NULL;
1292
1293 if (type == FL_FIT_TYPE) {
1294 /*
1295 * No need to split VA, it fully fits.
1296 *
1297 * | |
1298 * V NVA V
1299 * |---------------|
1300 */
1301 unlink_va(va, &free_vmap_area_root);
1302 kmem_cache_free(vmap_area_cachep, va);
1303 } else if (type == LE_FIT_TYPE) {
1304 /*
1305 * Split left edge of fit VA.
1306 *
1307 * | |
1308 * V NVA V R
1309 * |-------|-------|
1310 */
1311 va->va_start += size;
1312 } else if (type == RE_FIT_TYPE) {
1313 /*
1314 * Split right edge of fit VA.
1315 *
1316 * | |
1317 * L V NVA V
1318 * |-------|-------|
1319 */
1320 va->va_end = nva_start_addr;
1321 } else if (type == NE_FIT_TYPE) {
1322 /*
1323 * Split no edge of fit VA.
1324 *
1325 * | |
1326 * L V NVA V R
1327 * |---|-------|---|
1328 */
1329 lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
1330 if (unlikely(!lva)) {
1331 /*
1332 * For percpu allocator we do not do any pre-allocation
1333 * and leave it as it is. The reason is it most likely
1334 * never ends up with NE_FIT_TYPE splitting. In case of
1335 * percpu allocations offsets and sizes are aligned to
1336 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
1337 * are its main fitting cases.
1338 *
1339 * There are a few exceptions though, as an example it is
1340 * a first allocation (early boot up) when we have "one"
1341 * big free space that has to be split.
1342 *
1343 * Also we can hit this path in case of regular "vmap"
1344 * allocations, if "this" current CPU was not preloaded.
1345 * See the comment in alloc_vmap_area() why. If so, then
1346 * GFP_NOWAIT is used instead to get an extra object for
1347 * split purpose. That is rare and most time does not
1348 * occur.
1349 *
1350 * What happens if an allocation gets failed. Basically,
1351 * an "overflow" path is triggered to purge lazily freed
1352 * areas to free some memory, then, the "retry" path is
1353 * triggered to repeat one more time. See more details
1354 * in alloc_vmap_area() function.
1355 */
1356 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
1357 if (!lva)
1358 return -1;
1359 }
1360
1361 /*
1362 * Build the remainder.
1363 */
1364 lva->va_start = va->va_start;
1365 lva->va_end = nva_start_addr;
1366
1367 /*
1368 * Shrink this VA to remaining size.
1369 */
1370 va->va_start = nva_start_addr + size;
1371 } else {
1372 return -1;
1373 }
1374
1375 if (type != FL_FIT_TYPE) {
1376 augment_tree_propagate_from(va);
1377
1378 if (lva) /* type == NE_FIT_TYPE */
1379 insert_vmap_area_augment(lva, &va->rb_node,
1380 &free_vmap_area_root, &free_vmap_area_list);
1381 }
1382
1383 return 0;
1384}
1385
1386/*
1387 * Returns a start address of the newly allocated area, if success.
1388 * Otherwise a vend is returned that indicates failure.
1389 */
1390static __always_inline unsigned long
1391__alloc_vmap_area(unsigned long size, unsigned long align,
1392 unsigned long vstart, unsigned long vend)
1393{
1394 unsigned long nva_start_addr;
1395 struct vmap_area *va;
1396 enum fit_type type;
1397 int ret;
1398
1399 va = find_vmap_lowest_match(size, align, vstart);
1400 if (unlikely(!va))
1401 return vend;
1402
1403 if (va->va_start > vstart)
1404 nva_start_addr = ALIGN(va->va_start, align);
1405 else
1406 nva_start_addr = ALIGN(vstart, align);
1407
1408 /* Check the "vend" restriction. */
1409 if (nva_start_addr + size > vend)
1410 return vend;
1411
1412 /* Classify what we have found. */
1413 type = classify_va_fit_type(va, nva_start_addr, size);
1414 if (WARN_ON_ONCE(type == NOTHING_FIT))
1415 return vend;
1416
1417 /* Update the free vmap_area. */
1418 ret = adjust_va_to_fit_type(va, nva_start_addr, size, type);
1419 if (ret)
1420 return vend;
1421
1422#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1423 find_vmap_lowest_match_check(size);
1424#endif
1425
1426 return nva_start_addr;
1427}
1428
1429/*
1430 * Free a region of KVA allocated by alloc_vmap_area
1431 */
1432static void free_vmap_area(struct vmap_area *va)
1433{
1434 /*
1435 * Remove from the busy tree/list.
1436 */
1437 spin_lock(&vmap_area_lock);
1438 unlink_va(va, &vmap_area_root);
1439 spin_unlock(&vmap_area_lock);
1440
1441 /*
1442 * Insert/Merge it back to the free tree/list.
1443 */
1444 spin_lock(&free_vmap_area_lock);
1445 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list);
1446 spin_unlock(&free_vmap_area_lock);
1447}
1448
1449static inline void
1450preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
1451{
1452 struct vmap_area *va = NULL;
1453
1454 /*
1455 * Preload this CPU with one extra vmap_area object. It is used
1456 * when fit type of free area is NE_FIT_TYPE. It guarantees that
1457 * a CPU that does an allocation is preloaded.
1458 *
1459 * We do it in non-atomic context, thus it allows us to use more
1460 * permissive allocation masks to be more stable under low memory
1461 * condition and high memory pressure.
1462 */
1463 if (!this_cpu_read(ne_fit_preload_node))
1464 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1465
1466 spin_lock(lock);
1467
1468 if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va))
1469 kmem_cache_free(vmap_area_cachep, va);
1470}
1471
1472/*
1473 * Allocate a region of KVA of the specified size and alignment, within the
1474 * vstart and vend.
1475 */
1476static struct vmap_area *alloc_vmap_area(unsigned long size,
1477 unsigned long align,
1478 unsigned long vstart, unsigned long vend,
1479 int node, gfp_t gfp_mask)
1480{
1481 struct vmap_area *va;
1482 unsigned long addr;
1483 int purged = 0;
1484 int ret;
1485
1486 BUG_ON(!size);
1487 BUG_ON(offset_in_page(size));
1488 BUG_ON(!is_power_of_2(align));
1489
1490 if (unlikely(!vmap_initialized))
1491 return ERR_PTR(-EBUSY);
1492
1493 might_sleep();
1494 gfp_mask = gfp_mask & GFP_RECLAIM_MASK;
1495
1496 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1497 if (unlikely(!va))
1498 return ERR_PTR(-ENOMEM);
1499
1500 /*
1501 * Only scan the relevant parts containing pointers to other objects
1502 * to avoid false negatives.
1503 */
1504 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask);
1505
1506retry:
1507 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node);
1508 addr = __alloc_vmap_area(size, align, vstart, vend);
1509 spin_unlock(&free_vmap_area_lock);
1510
1511 /*
1512 * If an allocation fails, the "vend" address is
1513 * returned. Therefore trigger the overflow path.
1514 */
1515 if (unlikely(addr == vend))
1516 goto overflow;
1517
1518 va->va_start = addr;
1519 va->va_end = addr + size;
1520 va->vm = NULL;
1521
1522 spin_lock(&vmap_area_lock);
1523 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
1524 spin_unlock(&vmap_area_lock);
1525
1526 BUG_ON(!IS_ALIGNED(va->va_start, align));
1527 BUG_ON(va->va_start < vstart);
1528 BUG_ON(va->va_end > vend);
1529
1530 ret = kasan_populate_vmalloc(addr, size);
1531 if (ret) {
1532 free_vmap_area(va);
1533 return ERR_PTR(ret);
1534 }
1535
1536 return va;
1537
1538overflow:
1539 if (!purged) {
1540 purge_vmap_area_lazy();
1541 purged = 1;
1542 goto retry;
1543 }
1544
1545 if (gfpflags_allow_blocking(gfp_mask)) {
1546 unsigned long freed = 0;
1547 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
1548 if (freed > 0) {
1549 purged = 0;
1550 goto retry;
1551 }
1552 }
1553
1554 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
1555 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
1556 size);
1557
1558 kmem_cache_free(vmap_area_cachep, va);
1559 return ERR_PTR(-EBUSY);
1560}
1561
1562int register_vmap_purge_notifier(struct notifier_block *nb)
1563{
1564 return blocking_notifier_chain_register(&vmap_notify_list, nb);
1565}
1566EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
1567
1568int unregister_vmap_purge_notifier(struct notifier_block *nb)
1569{
1570 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
1571}
1572EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
1573
1574/*
1575 * lazy_max_pages is the maximum amount of virtual address space we gather up
1576 * before attempting to purge with a TLB flush.
1577 *
1578 * There is a tradeoff here: a larger number will cover more kernel page tables
1579 * and take slightly longer to purge, but it will linearly reduce the number of
1580 * global TLB flushes that must be performed. It would seem natural to scale
1581 * this number up linearly with the number of CPUs (because vmapping activity
1582 * could also scale linearly with the number of CPUs), however it is likely
1583 * that in practice, workloads might be constrained in other ways that mean
1584 * vmap activity will not scale linearly with CPUs. Also, I want to be
1585 * conservative and not introduce a big latency on huge systems, so go with
1586 * a less aggressive log scale. It will still be an improvement over the old
1587 * code, and it will be simple to change the scale factor if we find that it
1588 * becomes a problem on bigger systems.
1589 */
1590static unsigned long lazy_max_pages(void)
1591{
1592 unsigned int log;
1593
1594 log = fls(num_online_cpus());
1595
1596 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
1597}
1598
1599static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
1600
1601/*
1602 * Serialize vmap purging. There is no actual critical section protected
1603 * by this look, but we want to avoid concurrent calls for performance
1604 * reasons and to make the pcpu_get_vm_areas more deterministic.
1605 */
1606static DEFINE_MUTEX(vmap_purge_lock);
1607
1608/* for per-CPU blocks */
1609static void purge_fragmented_blocks_allcpus(void);
1610
1611#ifdef CONFIG_X86_64
1612/*
1613 * called before a call to iounmap() if the caller wants vm_area_struct's
1614 * immediately freed.
1615 */
1616void set_iounmap_nonlazy(void)
1617{
1618 atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1);
1619}
1620#endif /* CONFIG_X86_64 */
1621
1622/*
1623 * Purges all lazily-freed vmap areas.
1624 */
1625static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
1626{
1627 unsigned long resched_threshold;
1628 struct list_head local_pure_list;
1629 struct vmap_area *va, *n_va;
1630
1631 lockdep_assert_held(&vmap_purge_lock);
1632
1633 spin_lock(&purge_vmap_area_lock);
1634 purge_vmap_area_root = RB_ROOT;
1635 list_replace_init(&purge_vmap_area_list, &local_pure_list);
1636 spin_unlock(&purge_vmap_area_lock);
1637
1638 if (unlikely(list_empty(&local_pure_list)))
1639 return false;
1640
1641 start = min(start,
1642 list_first_entry(&local_pure_list,
1643 struct vmap_area, list)->va_start);
1644
1645 end = max(end,
1646 list_last_entry(&local_pure_list,
1647 struct vmap_area, list)->va_end);
1648
1649 flush_tlb_kernel_range(start, end);
1650 resched_threshold = lazy_max_pages() << 1;
1651
1652 spin_lock(&free_vmap_area_lock);
1653 list_for_each_entry_safe(va, n_va, &local_pure_list, list) {
1654 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
1655 unsigned long orig_start = va->va_start;
1656 unsigned long orig_end = va->va_end;
1657
1658 /*
1659 * Finally insert or merge lazily-freed area. It is
1660 * detached and there is no need to "unlink" it from
1661 * anything.
1662 */
1663 va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root,
1664 &free_vmap_area_list);
1665
1666 if (!va)
1667 continue;
1668
1669 if (is_vmalloc_or_module_addr((void *)orig_start))
1670 kasan_release_vmalloc(orig_start, orig_end,
1671 va->va_start, va->va_end);
1672
1673 atomic_long_sub(nr, &vmap_lazy_nr);
1674
1675 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
1676 cond_resched_lock(&free_vmap_area_lock);
1677 }
1678 spin_unlock(&free_vmap_area_lock);
1679 return true;
1680}
1681
1682/*
1683 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
1684 * is already purging.
1685 */
1686static void try_purge_vmap_area_lazy(void)
1687{
1688 if (mutex_trylock(&vmap_purge_lock)) {
1689 __purge_vmap_area_lazy(ULONG_MAX, 0);
1690 mutex_unlock(&vmap_purge_lock);
1691 }
1692}
1693
1694/*
1695 * Kick off a purge of the outstanding lazy areas.
1696 */
1697static void purge_vmap_area_lazy(void)
1698{
1699 mutex_lock(&vmap_purge_lock);
1700 purge_fragmented_blocks_allcpus();
1701 __purge_vmap_area_lazy(ULONG_MAX, 0);
1702 mutex_unlock(&vmap_purge_lock);
1703}
1704
1705/*
1706 * Free a vmap area, caller ensuring that the area has been unmapped
1707 * and flush_cache_vunmap had been called for the correct range
1708 * previously.
1709 */
1710static void free_vmap_area_noflush(struct vmap_area *va)
1711{
1712 unsigned long nr_lazy;
1713
1714 spin_lock(&vmap_area_lock);
1715 unlink_va(va, &vmap_area_root);
1716 spin_unlock(&vmap_area_lock);
1717
1718 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
1719 PAGE_SHIFT, &vmap_lazy_nr);
1720
1721 /*
1722 * Merge or place it to the purge tree/list.
1723 */
1724 spin_lock(&purge_vmap_area_lock);
1725 merge_or_add_vmap_area(va,
1726 &purge_vmap_area_root, &purge_vmap_area_list);
1727 spin_unlock(&purge_vmap_area_lock);
1728
1729 /* After this point, we may free va at any time */
1730 if (unlikely(nr_lazy > lazy_max_pages()))
1731 try_purge_vmap_area_lazy();
1732}
1733
1734/*
1735 * Free and unmap a vmap area
1736 */
1737static void free_unmap_vmap_area(struct vmap_area *va)
1738{
1739 flush_cache_vunmap(va->va_start, va->va_end);
1740 vunmap_range_noflush(va->va_start, va->va_end);
1741 if (debug_pagealloc_enabled_static())
1742 flush_tlb_kernel_range(va->va_start, va->va_end);
1743
1744 free_vmap_area_noflush(va);
1745}
1746
1747static struct vmap_area *find_vmap_area(unsigned long addr)
1748{
1749 struct vmap_area *va;
1750
1751 spin_lock(&vmap_area_lock);
1752 va = __find_vmap_area(addr);
1753 spin_unlock(&vmap_area_lock);
1754
1755 return va;
1756}
1757
1758/*** Per cpu kva allocator ***/
1759
1760/*
1761 * vmap space is limited especially on 32 bit architectures. Ensure there is
1762 * room for at least 16 percpu vmap blocks per CPU.
1763 */
1764/*
1765 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
1766 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
1767 * instead (we just need a rough idea)
1768 */
1769#if BITS_PER_LONG == 32
1770#define VMALLOC_SPACE (128UL*1024*1024)
1771#else
1772#define VMALLOC_SPACE (128UL*1024*1024*1024)
1773#endif
1774
1775#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
1776#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
1777#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
1778#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
1779#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
1780#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
1781#define VMAP_BBMAP_BITS \
1782 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
1783 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
1784 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
1785
1786#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
1787
1788struct vmap_block_queue {
1789 spinlock_t lock;
1790 struct list_head free;
1791};
1792
1793struct vmap_block {
1794 spinlock_t lock;
1795 struct vmap_area *va;
1796 unsigned long free, dirty;
1797 unsigned long dirty_min, dirty_max; /*< dirty range */
1798 struct list_head free_list;
1799 struct rcu_head rcu_head;
1800 struct list_head purge;
1801};
1802
1803/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
1804static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
1805
1806/*
1807 * XArray of vmap blocks, indexed by address, to quickly find a vmap block
1808 * in the free path. Could get rid of this if we change the API to return a
1809 * "cookie" from alloc, to be passed to free. But no big deal yet.
1810 */
1811static DEFINE_XARRAY(vmap_blocks);
1812
1813/*
1814 * We should probably have a fallback mechanism to allocate virtual memory
1815 * out of partially filled vmap blocks. However vmap block sizing should be
1816 * fairly reasonable according to the vmalloc size, so it shouldn't be a
1817 * big problem.
1818 */
1819
1820static unsigned long addr_to_vb_idx(unsigned long addr)
1821{
1822 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
1823 addr /= VMAP_BLOCK_SIZE;
1824 return addr;
1825}
1826
1827static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
1828{
1829 unsigned long addr;
1830
1831 addr = va_start + (pages_off << PAGE_SHIFT);
1832 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
1833 return (void *)addr;
1834}
1835
1836/**
1837 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
1838 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
1839 * @order: how many 2^order pages should be occupied in newly allocated block
1840 * @gfp_mask: flags for the page level allocator
1841 *
1842 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
1843 */
1844static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
1845{
1846 struct vmap_block_queue *vbq;
1847 struct vmap_block *vb;
1848 struct vmap_area *va;
1849 unsigned long vb_idx;
1850 int node, err;
1851 void *vaddr;
1852
1853 node = numa_node_id();
1854
1855 vb = kmalloc_node(sizeof(struct vmap_block),
1856 gfp_mask & GFP_RECLAIM_MASK, node);
1857 if (unlikely(!vb))
1858 return ERR_PTR(-ENOMEM);
1859
1860 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
1861 VMALLOC_START, VMALLOC_END,
1862 node, gfp_mask);
1863 if (IS_ERR(va)) {
1864 kfree(vb);
1865 return ERR_CAST(va);
1866 }
1867
1868 vaddr = vmap_block_vaddr(va->va_start, 0);
1869 spin_lock_init(&vb->lock);
1870 vb->va = va;
1871 /* At least something should be left free */
1872 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
1873 vb->free = VMAP_BBMAP_BITS - (1UL << order);
1874 vb->dirty = 0;
1875 vb->dirty_min = VMAP_BBMAP_BITS;
1876 vb->dirty_max = 0;
1877 INIT_LIST_HEAD(&vb->free_list);
1878
1879 vb_idx = addr_to_vb_idx(va->va_start);
1880 err = xa_insert(&vmap_blocks, vb_idx, vb, gfp_mask);
1881 if (err) {
1882 kfree(vb);
1883 free_vmap_area(va);
1884 return ERR_PTR(err);
1885 }
1886
1887 vbq = &get_cpu_var(vmap_block_queue);
1888 spin_lock(&vbq->lock);
1889 list_add_tail_rcu(&vb->free_list, &vbq->free);
1890 spin_unlock(&vbq->lock);
1891 put_cpu_var(vmap_block_queue);
1892
1893 return vaddr;
1894}
1895
1896static void free_vmap_block(struct vmap_block *vb)
1897{
1898 struct vmap_block *tmp;
1899
1900 tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start));
1901 BUG_ON(tmp != vb);
1902
1903 free_vmap_area_noflush(vb->va);
1904 kfree_rcu(vb, rcu_head);
1905}
1906
1907static void purge_fragmented_blocks(int cpu)
1908{
1909 LIST_HEAD(purge);
1910 struct vmap_block *vb;
1911 struct vmap_block *n_vb;
1912 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1913
1914 rcu_read_lock();
1915 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1916
1917 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
1918 continue;
1919
1920 spin_lock(&vb->lock);
1921 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
1922 vb->free = 0; /* prevent further allocs after releasing lock */
1923 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
1924 vb->dirty_min = 0;
1925 vb->dirty_max = VMAP_BBMAP_BITS;
1926 spin_lock(&vbq->lock);
1927 list_del_rcu(&vb->free_list);
1928 spin_unlock(&vbq->lock);
1929 spin_unlock(&vb->lock);
1930 list_add_tail(&vb->purge, &purge);
1931 } else
1932 spin_unlock(&vb->lock);
1933 }
1934 rcu_read_unlock();
1935
1936 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
1937 list_del(&vb->purge);
1938 free_vmap_block(vb);
1939 }
1940}
1941
1942static void purge_fragmented_blocks_allcpus(void)
1943{
1944 int cpu;
1945
1946 for_each_possible_cpu(cpu)
1947 purge_fragmented_blocks(cpu);
1948}
1949
1950static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
1951{
1952 struct vmap_block_queue *vbq;
1953 struct vmap_block *vb;
1954 void *vaddr = NULL;
1955 unsigned int order;
1956
1957 BUG_ON(offset_in_page(size));
1958 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
1959 if (WARN_ON(size == 0)) {
1960 /*
1961 * Allocating 0 bytes isn't what caller wants since
1962 * get_order(0) returns funny result. Just warn and terminate
1963 * early.
1964 */
1965 return NULL;
1966 }
1967 order = get_order(size);
1968
1969 rcu_read_lock();
1970 vbq = &get_cpu_var(vmap_block_queue);
1971 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1972 unsigned long pages_off;
1973
1974 spin_lock(&vb->lock);
1975 if (vb->free < (1UL << order)) {
1976 spin_unlock(&vb->lock);
1977 continue;
1978 }
1979
1980 pages_off = VMAP_BBMAP_BITS - vb->free;
1981 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
1982 vb->free -= 1UL << order;
1983 if (vb->free == 0) {
1984 spin_lock(&vbq->lock);
1985 list_del_rcu(&vb->free_list);
1986 spin_unlock(&vbq->lock);
1987 }
1988
1989 spin_unlock(&vb->lock);
1990 break;
1991 }
1992
1993 put_cpu_var(vmap_block_queue);
1994 rcu_read_unlock();
1995
1996 /* Allocate new block if nothing was found */
1997 if (!vaddr)
1998 vaddr = new_vmap_block(order, gfp_mask);
1999
2000 return vaddr;
2001}
2002
2003static void vb_free(unsigned long addr, unsigned long size)
2004{
2005 unsigned long offset;
2006 unsigned int order;
2007 struct vmap_block *vb;
2008
2009 BUG_ON(offset_in_page(size));
2010 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2011
2012 flush_cache_vunmap(addr, addr + size);
2013
2014 order = get_order(size);
2015 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
2016 vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr));
2017
2018 vunmap_range_noflush(addr, addr + size);
2019
2020 if (debug_pagealloc_enabled_static())
2021 flush_tlb_kernel_range(addr, addr + size);
2022
2023 spin_lock(&vb->lock);
2024
2025 /* Expand dirty range */
2026 vb->dirty_min = min(vb->dirty_min, offset);
2027 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
2028
2029 vb->dirty += 1UL << order;
2030 if (vb->dirty == VMAP_BBMAP_BITS) {
2031 BUG_ON(vb->free);
2032 spin_unlock(&vb->lock);
2033 free_vmap_block(vb);
2034 } else
2035 spin_unlock(&vb->lock);
2036}
2037
2038static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
2039{
2040 int cpu;
2041
2042 if (unlikely(!vmap_initialized))
2043 return;
2044
2045 might_sleep();
2046
2047 for_each_possible_cpu(cpu) {
2048 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2049 struct vmap_block *vb;
2050
2051 rcu_read_lock();
2052 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2053 spin_lock(&vb->lock);
2054 if (vb->dirty && vb->dirty != VMAP_BBMAP_BITS) {
2055 unsigned long va_start = vb->va->va_start;
2056 unsigned long s, e;
2057
2058 s = va_start + (vb->dirty_min << PAGE_SHIFT);
2059 e = va_start + (vb->dirty_max << PAGE_SHIFT);
2060
2061 start = min(s, start);
2062 end = max(e, end);
2063
2064 flush = 1;
2065 }
2066 spin_unlock(&vb->lock);
2067 }
2068 rcu_read_unlock();
2069 }
2070
2071 mutex_lock(&vmap_purge_lock);
2072 purge_fragmented_blocks_allcpus();
2073 if (!__purge_vmap_area_lazy(start, end) && flush)
2074 flush_tlb_kernel_range(start, end);
2075 mutex_unlock(&vmap_purge_lock);
2076}
2077
2078/**
2079 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
2080 *
2081 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
2082 * to amortize TLB flushing overheads. What this means is that any page you
2083 * have now, may, in a former life, have been mapped into kernel virtual
2084 * address by the vmap layer and so there might be some CPUs with TLB entries
2085 * still referencing that page (additional to the regular 1:1 kernel mapping).
2086 *
2087 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
2088 * be sure that none of the pages we have control over will have any aliases
2089 * from the vmap layer.
2090 */
2091void vm_unmap_aliases(void)
2092{
2093 unsigned long start = ULONG_MAX, end = 0;
2094 int flush = 0;
2095
2096 _vm_unmap_aliases(start, end, flush);
2097}
2098EXPORT_SYMBOL_GPL(vm_unmap_aliases);
2099
2100/**
2101 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
2102 * @mem: the pointer returned by vm_map_ram
2103 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
2104 */
2105void vm_unmap_ram(const void *mem, unsigned int count)
2106{
2107 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2108 unsigned long addr = (unsigned long)mem;
2109 struct vmap_area *va;
2110
2111 might_sleep();
2112 BUG_ON(!addr);
2113 BUG_ON(addr < VMALLOC_START);
2114 BUG_ON(addr > VMALLOC_END);
2115 BUG_ON(!PAGE_ALIGNED(addr));
2116
2117 kasan_poison_vmalloc(mem, size);
2118
2119 if (likely(count <= VMAP_MAX_ALLOC)) {
2120 debug_check_no_locks_freed(mem, size);
2121 vb_free(addr, size);
2122 return;
2123 }
2124
2125 va = find_vmap_area(addr);
2126 BUG_ON(!va);
2127 debug_check_no_locks_freed((void *)va->va_start,
2128 (va->va_end - va->va_start));
2129 free_unmap_vmap_area(va);
2130}
2131EXPORT_SYMBOL(vm_unmap_ram);
2132
2133/**
2134 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
2135 * @pages: an array of pointers to the pages to be mapped
2136 * @count: number of pages
2137 * @node: prefer to allocate data structures on this node
2138 *
2139 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
2140 * faster than vmap so it's good. But if you mix long-life and short-life
2141 * objects with vm_map_ram(), it could consume lots of address space through
2142 * fragmentation (especially on a 32bit machine). You could see failures in
2143 * the end. Please use this function for short-lived objects.
2144 *
2145 * Returns: a pointer to the address that has been mapped, or %NULL on failure
2146 */
2147void *vm_map_ram(struct page **pages, unsigned int count, int node)
2148{
2149 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2150 unsigned long addr;
2151 void *mem;
2152
2153 if (likely(count <= VMAP_MAX_ALLOC)) {
2154 mem = vb_alloc(size, GFP_KERNEL);
2155 if (IS_ERR(mem))
2156 return NULL;
2157 addr = (unsigned long)mem;
2158 } else {
2159 struct vmap_area *va;
2160 va = alloc_vmap_area(size, PAGE_SIZE,
2161 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
2162 if (IS_ERR(va))
2163 return NULL;
2164
2165 addr = va->va_start;
2166 mem = (void *)addr;
2167 }
2168
2169 kasan_unpoison_vmalloc(mem, size);
2170
2171 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
2172 pages, PAGE_SHIFT) < 0) {
2173 vm_unmap_ram(mem, count);
2174 return NULL;
2175 }
2176
2177 return mem;
2178}
2179EXPORT_SYMBOL(vm_map_ram);
2180
2181static struct vm_struct *vmlist __initdata;
2182
2183static inline unsigned int vm_area_page_order(struct vm_struct *vm)
2184{
2185#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2186 return vm->page_order;
2187#else
2188 return 0;
2189#endif
2190}
2191
2192static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
2193{
2194#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2195 vm->page_order = order;
2196#else
2197 BUG_ON(order != 0);
2198#endif
2199}
2200
2201/**
2202 * vm_area_add_early - add vmap area early during boot
2203 * @vm: vm_struct to add
2204 *
2205 * This function is used to add fixed kernel vm area to vmlist before
2206 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
2207 * should contain proper values and the other fields should be zero.
2208 *
2209 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2210 */
2211void __init vm_area_add_early(struct vm_struct *vm)
2212{
2213 struct vm_struct *tmp, **p;
2214
2215 BUG_ON(vmap_initialized);
2216 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
2217 if (tmp->addr >= vm->addr) {
2218 BUG_ON(tmp->addr < vm->addr + vm->size);
2219 break;
2220 } else
2221 BUG_ON(tmp->addr + tmp->size > vm->addr);
2222 }
2223 vm->next = *p;
2224 *p = vm;
2225}
2226
2227/**
2228 * vm_area_register_early - register vmap area early during boot
2229 * @vm: vm_struct to register
2230 * @align: requested alignment
2231 *
2232 * This function is used to register kernel vm area before
2233 * vmalloc_init() is called. @vm->size and @vm->flags should contain
2234 * proper values on entry and other fields should be zero. On return,
2235 * vm->addr contains the allocated address.
2236 *
2237 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2238 */
2239void __init vm_area_register_early(struct vm_struct *vm, size_t align)
2240{
2241 static size_t vm_init_off __initdata;
2242 unsigned long addr;
2243
2244 addr = ALIGN(VMALLOC_START + vm_init_off, align);
2245 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
2246
2247 vm->addr = (void *)addr;
2248
2249 vm_area_add_early(vm);
2250}
2251
2252static void vmap_init_free_space(void)
2253{
2254 unsigned long vmap_start = 1;
2255 const unsigned long vmap_end = ULONG_MAX;
2256 struct vmap_area *busy, *free;
2257
2258 /*
2259 * B F B B B F
2260 * -|-----|.....|-----|-----|-----|.....|-
2261 * | The KVA space |
2262 * |<--------------------------------->|
2263 */
2264 list_for_each_entry(busy, &vmap_area_list, list) {
2265 if (busy->va_start - vmap_start > 0) {
2266 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2267 if (!WARN_ON_ONCE(!free)) {
2268 free->va_start = vmap_start;
2269 free->va_end = busy->va_start;
2270
2271 insert_vmap_area_augment(free, NULL,
2272 &free_vmap_area_root,
2273 &free_vmap_area_list);
2274 }
2275 }
2276
2277 vmap_start = busy->va_end;
2278 }
2279
2280 if (vmap_end - vmap_start > 0) {
2281 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2282 if (!WARN_ON_ONCE(!free)) {
2283 free->va_start = vmap_start;
2284 free->va_end = vmap_end;
2285
2286 insert_vmap_area_augment(free, NULL,
2287 &free_vmap_area_root,
2288 &free_vmap_area_list);
2289 }
2290 }
2291}
2292
2293void __init vmalloc_init(void)
2294{
2295 struct vmap_area *va;
2296 struct vm_struct *tmp;
2297 int i;
2298
2299 /*
2300 * Create the cache for vmap_area objects.
2301 */
2302 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
2303
2304 for_each_possible_cpu(i) {
2305 struct vmap_block_queue *vbq;
2306 struct vfree_deferred *p;
2307
2308 vbq = &per_cpu(vmap_block_queue, i);
2309 spin_lock_init(&vbq->lock);
2310 INIT_LIST_HEAD(&vbq->free);
2311 p = &per_cpu(vfree_deferred, i);
2312 init_llist_head(&p->list);
2313 INIT_WORK(&p->wq, free_work);
2314 }
2315
2316 /* Import existing vmlist entries. */
2317 for (tmp = vmlist; tmp; tmp = tmp->next) {
2318 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2319 if (WARN_ON_ONCE(!va))
2320 continue;
2321
2322 va->va_start = (unsigned long)tmp->addr;
2323 va->va_end = va->va_start + tmp->size;
2324 va->vm = tmp;
2325 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
2326 }
2327
2328 /*
2329 * Now we can initialize a free vmap space.
2330 */
2331 vmap_init_free_space();
2332 vmap_initialized = true;
2333}
2334
2335static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
2336 struct vmap_area *va, unsigned long flags, const void *caller)
2337{
2338 vm->flags = flags;
2339 vm->addr = (void *)va->va_start;
2340 vm->size = va->va_end - va->va_start;
2341 vm->caller = caller;
2342 va->vm = vm;
2343}
2344
2345static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
2346 unsigned long flags, const void *caller)
2347{
2348 spin_lock(&vmap_area_lock);
2349 setup_vmalloc_vm_locked(vm, va, flags, caller);
2350 spin_unlock(&vmap_area_lock);
2351}
2352
2353static void clear_vm_uninitialized_flag(struct vm_struct *vm)
2354{
2355 /*
2356 * Before removing VM_UNINITIALIZED,
2357 * we should make sure that vm has proper values.
2358 * Pair with smp_rmb() in show_numa_info().
2359 */
2360 smp_wmb();
2361 vm->flags &= ~VM_UNINITIALIZED;
2362}
2363
2364static struct vm_struct *__get_vm_area_node(unsigned long size,
2365 unsigned long align, unsigned long shift, unsigned long flags,
2366 unsigned long start, unsigned long end, int node,
2367 gfp_t gfp_mask, const void *caller)
2368{
2369 struct vmap_area *va;
2370 struct vm_struct *area;
2371 unsigned long requested_size = size;
2372
2373 BUG_ON(in_interrupt());
2374 size = ALIGN(size, 1ul << shift);
2375 if (unlikely(!size))
2376 return NULL;
2377
2378 if (flags & VM_IOREMAP)
2379 align = 1ul << clamp_t(int, get_count_order_long(size),
2380 PAGE_SHIFT, IOREMAP_MAX_ORDER);
2381
2382 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
2383 if (unlikely(!area))
2384 return NULL;
2385
2386 if (!(flags & VM_NO_GUARD))
2387 size += PAGE_SIZE;
2388
2389 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
2390 if (IS_ERR(va)) {
2391 kfree(area);
2392 return NULL;
2393 }
2394
2395 kasan_unpoison_vmalloc((void *)va->va_start, requested_size);
2396
2397 setup_vmalloc_vm(area, va, flags, caller);
2398
2399 return area;
2400}
2401
2402struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
2403 unsigned long start, unsigned long end,
2404 const void *caller)
2405{
2406 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end,
2407 NUMA_NO_NODE, GFP_KERNEL, caller);
2408}
2409
2410/**
2411 * get_vm_area - reserve a contiguous kernel virtual area
2412 * @size: size of the area
2413 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
2414 *
2415 * Search an area of @size in the kernel virtual mapping area,
2416 * and reserved it for out purposes. Returns the area descriptor
2417 * on success or %NULL on failure.
2418 *
2419 * Return: the area descriptor on success or %NULL on failure.
2420 */
2421struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
2422{
2423 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2424 VMALLOC_START, VMALLOC_END,
2425 NUMA_NO_NODE, GFP_KERNEL,
2426 __builtin_return_address(0));
2427}
2428
2429struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
2430 const void *caller)
2431{
2432 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2433 VMALLOC_START, VMALLOC_END,
2434 NUMA_NO_NODE, GFP_KERNEL, caller);
2435}
2436
2437/**
2438 * find_vm_area - find a continuous kernel virtual area
2439 * @addr: base address
2440 *
2441 * Search for the kernel VM area starting at @addr, and return it.
2442 * It is up to the caller to do all required locking to keep the returned
2443 * pointer valid.
2444 *
2445 * Return: the area descriptor on success or %NULL on failure.
2446 */
2447struct vm_struct *find_vm_area(const void *addr)
2448{
2449 struct vmap_area *va;
2450
2451 va = find_vmap_area((unsigned long)addr);
2452 if (!va)
2453 return NULL;
2454
2455 return va->vm;
2456}
2457
2458/**
2459 * remove_vm_area - find and remove a continuous kernel virtual area
2460 * @addr: base address
2461 *
2462 * Search for the kernel VM area starting at @addr, and remove it.
2463 * This function returns the found VM area, but using it is NOT safe
2464 * on SMP machines, except for its size or flags.
2465 *
2466 * Return: the area descriptor on success or %NULL on failure.
2467 */
2468struct vm_struct *remove_vm_area(const void *addr)
2469{
2470 struct vmap_area *va;
2471
2472 might_sleep();
2473
2474 spin_lock(&vmap_area_lock);
2475 va = __find_vmap_area((unsigned long)addr);
2476 if (va && va->vm) {
2477 struct vm_struct *vm = va->vm;
2478
2479 va->vm = NULL;
2480 spin_unlock(&vmap_area_lock);
2481
2482 kasan_free_shadow(vm);
2483 free_unmap_vmap_area(va);
2484
2485 return vm;
2486 }
2487
2488 spin_unlock(&vmap_area_lock);
2489 return NULL;
2490}
2491
2492static inline void set_area_direct_map(const struct vm_struct *area,
2493 int (*set_direct_map)(struct page *page))
2494{
2495 int i;
2496
2497 /* HUGE_VMALLOC passes small pages to set_direct_map */
2498 for (i = 0; i < area->nr_pages; i++)
2499 if (page_address(area->pages[i]))
2500 set_direct_map(area->pages[i]);
2501}
2502
2503/* Handle removing and resetting vm mappings related to the vm_struct. */
2504static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
2505{
2506 unsigned long start = ULONG_MAX, end = 0;
2507 unsigned int page_order = vm_area_page_order(area);
2508 int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
2509 int flush_dmap = 0;
2510 int i;
2511
2512 remove_vm_area(area->addr);
2513
2514 /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
2515 if (!flush_reset)
2516 return;
2517
2518 /*
2519 * If not deallocating pages, just do the flush of the VM area and
2520 * return.
2521 */
2522 if (!deallocate_pages) {
2523 vm_unmap_aliases();
2524 return;
2525 }
2526
2527 /*
2528 * If execution gets here, flush the vm mapping and reset the direct
2529 * map. Find the start and end range of the direct mappings to make sure
2530 * the vm_unmap_aliases() flush includes the direct map.
2531 */
2532 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
2533 unsigned long addr = (unsigned long)page_address(area->pages[i]);
2534 if (addr) {
2535 unsigned long page_size;
2536
2537 page_size = PAGE_SIZE << page_order;
2538 start = min(addr, start);
2539 end = max(addr + page_size, end);
2540 flush_dmap = 1;
2541 }
2542 }
2543
2544 /*
2545 * Set direct map to something invalid so that it won't be cached if
2546 * there are any accesses after the TLB flush, then flush the TLB and
2547 * reset the direct map permissions to the default.
2548 */
2549 set_area_direct_map(area, set_direct_map_invalid_noflush);
2550 _vm_unmap_aliases(start, end, flush_dmap);
2551 set_area_direct_map(area, set_direct_map_default_noflush);
2552}
2553
2554static void __vunmap(const void *addr, int deallocate_pages)
2555{
2556 struct vm_struct *area;
2557
2558 if (!addr)
2559 return;
2560
2561 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
2562 addr))
2563 return;
2564
2565 area = find_vm_area(addr);
2566 if (unlikely(!area)) {
2567 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
2568 addr);
2569 return;
2570 }
2571
2572 debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
2573 debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
2574
2575 kasan_poison_vmalloc(area->addr, get_vm_area_size(area));
2576
2577 vm_remove_mappings(area, deallocate_pages);
2578
2579 if (deallocate_pages) {
2580 unsigned int page_order = vm_area_page_order(area);
2581 int i;
2582
2583 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
2584 struct page *page = area->pages[i];
2585
2586 BUG_ON(!page);
2587 __free_pages(page, page_order);
2588 cond_resched();
2589 }
2590 atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
2591
2592 kvfree(area->pages);
2593 }
2594
2595 kfree(area);
2596}
2597
2598static inline void __vfree_deferred(const void *addr)
2599{
2600 /*
2601 * Use raw_cpu_ptr() because this can be called from preemptible
2602 * context. Preemption is absolutely fine here, because the llist_add()
2603 * implementation is lockless, so it works even if we are adding to
2604 * another cpu's list. schedule_work() should be fine with this too.
2605 */
2606 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
2607
2608 if (llist_add((struct llist_node *)addr, &p->list))
2609 schedule_work(&p->wq);
2610}
2611
2612/**
2613 * vfree_atomic - release memory allocated by vmalloc()
2614 * @addr: memory base address
2615 *
2616 * This one is just like vfree() but can be called in any atomic context
2617 * except NMIs.
2618 */
2619void vfree_atomic(const void *addr)
2620{
2621 BUG_ON(in_nmi());
2622
2623 kmemleak_free(addr);
2624
2625 if (!addr)
2626 return;
2627 __vfree_deferred(addr);
2628}
2629
2630static void __vfree(const void *addr)
2631{
2632 if (unlikely(in_interrupt()))
2633 __vfree_deferred(addr);
2634 else
2635 __vunmap(addr, 1);
2636}
2637
2638/**
2639 * vfree - Release memory allocated by vmalloc()
2640 * @addr: Memory base address
2641 *
2642 * Free the virtually continuous memory area starting at @addr, as obtained
2643 * from one of the vmalloc() family of APIs. This will usually also free the
2644 * physical memory underlying the virtual allocation, but that memory is
2645 * reference counted, so it will not be freed until the last user goes away.
2646 *
2647 * If @addr is NULL, no operation is performed.
2648 *
2649 * Context:
2650 * May sleep if called *not* from interrupt context.
2651 * Must not be called in NMI context (strictly speaking, it could be
2652 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
2653 * conventions for vfree() arch-dependent would be a really bad idea).
2654 */
2655void vfree(const void *addr)
2656{
2657 BUG_ON(in_nmi());
2658
2659 kmemleak_free(addr);
2660
2661 might_sleep_if(!in_interrupt());
2662
2663 if (!addr)
2664 return;
2665
2666 __vfree(addr);
2667}
2668EXPORT_SYMBOL(vfree);
2669
2670/**
2671 * vunmap - release virtual mapping obtained by vmap()
2672 * @addr: memory base address
2673 *
2674 * Free the virtually contiguous memory area starting at @addr,
2675 * which was created from the page array passed to vmap().
2676 *
2677 * Must not be called in interrupt context.
2678 */
2679void vunmap(const void *addr)
2680{
2681 BUG_ON(in_interrupt());
2682 might_sleep();
2683 if (addr)
2684 __vunmap(addr, 0);
2685}
2686EXPORT_SYMBOL(vunmap);
2687
2688/**
2689 * vmap - map an array of pages into virtually contiguous space
2690 * @pages: array of page pointers
2691 * @count: number of pages to map
2692 * @flags: vm_area->flags
2693 * @prot: page protection for the mapping
2694 *
2695 * Maps @count pages from @pages into contiguous kernel virtual space.
2696 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
2697 * (which must be kmalloc or vmalloc memory) and one reference per pages in it
2698 * are transferred from the caller to vmap(), and will be freed / dropped when
2699 * vfree() is called on the return value.
2700 *
2701 * Return: the address of the area or %NULL on failure
2702 */
2703void *vmap(struct page **pages, unsigned int count,
2704 unsigned long flags, pgprot_t prot)
2705{
2706 struct vm_struct *area;
2707 unsigned long addr;
2708 unsigned long size; /* In bytes */
2709
2710 might_sleep();
2711
2712 if (count > totalram_pages())
2713 return NULL;
2714
2715 size = (unsigned long)count << PAGE_SHIFT;
2716 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
2717 if (!area)
2718 return NULL;
2719
2720 addr = (unsigned long)area->addr;
2721 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
2722 pages, PAGE_SHIFT) < 0) {
2723 vunmap(area->addr);
2724 return NULL;
2725 }
2726
2727 if (flags & VM_MAP_PUT_PAGES) {
2728 area->pages = pages;
2729 area->nr_pages = count;
2730 }
2731 return area->addr;
2732}
2733EXPORT_SYMBOL(vmap);
2734
2735#ifdef CONFIG_VMAP_PFN
2736struct vmap_pfn_data {
2737 unsigned long *pfns;
2738 pgprot_t prot;
2739 unsigned int idx;
2740};
2741
2742static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
2743{
2744 struct vmap_pfn_data *data = private;
2745
2746 if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx])))
2747 return -EINVAL;
2748 *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
2749 return 0;
2750}
2751
2752/**
2753 * vmap_pfn - map an array of PFNs into virtually contiguous space
2754 * @pfns: array of PFNs
2755 * @count: number of pages to map
2756 * @prot: page protection for the mapping
2757 *
2758 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
2759 * the start address of the mapping.
2760 */
2761void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
2762{
2763 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) };
2764 struct vm_struct *area;
2765
2766 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP,
2767 __builtin_return_address(0));
2768 if (!area)
2769 return NULL;
2770 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2771 count * PAGE_SIZE, vmap_pfn_apply, &data)) {
2772 free_vm_area(area);
2773 return NULL;
2774 }
2775 return area->addr;
2776}
2777EXPORT_SYMBOL_GPL(vmap_pfn);
2778#endif /* CONFIG_VMAP_PFN */
2779
2780static inline unsigned int
2781vm_area_alloc_pages(gfp_t gfp, int nid,
2782 unsigned int order, unsigned long nr_pages, struct page **pages)
2783{
2784 unsigned int nr_allocated = 0;
2785
2786 /*
2787 * For order-0 pages we make use of bulk allocator, if
2788 * the page array is partly or not at all populated due
2789 * to fails, fallback to a single page allocator that is
2790 * more permissive.
2791 */
2792 if (!order)
2793 nr_allocated = alloc_pages_bulk_array_node(
2794 gfp, nid, nr_pages, pages);
2795 else
2796 /*
2797 * Compound pages required for remap_vmalloc_page if
2798 * high-order pages.
2799 */
2800 gfp |= __GFP_COMP;
2801
2802 /* High-order pages or fallback path if "bulk" fails. */
2803 while (nr_allocated < nr_pages) {
2804 struct page *page;
2805 int i;
2806
2807 page = alloc_pages_node(nid, gfp, order);
2808 if (unlikely(!page))
2809 break;
2810
2811 /*
2812 * Careful, we allocate and map page-order pages, but
2813 * tracking is done per PAGE_SIZE page so as to keep the
2814 * vm_struct APIs independent of the physical/mapped size.
2815 */
2816 for (i = 0; i < (1U << order); i++)
2817 pages[nr_allocated + i] = page + i;
2818
2819 if (gfpflags_allow_blocking(gfp))
2820 cond_resched();
2821
2822 nr_allocated += 1U << order;
2823 }
2824
2825 return nr_allocated;
2826}
2827
2828static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
2829 pgprot_t prot, unsigned int page_shift,
2830 int node)
2831{
2832 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
2833 unsigned long addr = (unsigned long)area->addr;
2834 unsigned long size = get_vm_area_size(area);
2835 unsigned long array_size;
2836 unsigned int nr_small_pages = size >> PAGE_SHIFT;
2837 unsigned int page_order;
2838
2839 array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
2840 gfp_mask |= __GFP_NOWARN;
2841 if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
2842 gfp_mask |= __GFP_HIGHMEM;
2843
2844 /* Please note that the recursion is strictly bounded. */
2845 if (array_size > PAGE_SIZE) {
2846 area->pages = __vmalloc_node(array_size, 1, nested_gfp, node,
2847 area->caller);
2848 } else {
2849 area->pages = kmalloc_node(array_size, nested_gfp, node);
2850 }
2851
2852 if (!area->pages) {
2853 warn_alloc(gfp_mask, NULL,
2854 "vmalloc error: size %lu, failed to allocated page array size %lu",
2855 nr_small_pages * PAGE_SIZE, array_size);
2856 free_vm_area(area);
2857 return NULL;
2858 }
2859
2860 set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
2861 page_order = vm_area_page_order(area);
2862
2863 area->nr_pages = vm_area_alloc_pages(gfp_mask, node,
2864 page_order, nr_small_pages, area->pages);
2865
2866 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
2867
2868 /*
2869 * If not enough pages were obtained to accomplish an
2870 * allocation request, free them via __vfree() if any.
2871 */
2872 if (area->nr_pages != nr_small_pages) {
2873 warn_alloc(gfp_mask, NULL,
2874 "vmalloc error: size %lu, page order %u, failed to allocate pages",
2875 area->nr_pages * PAGE_SIZE, page_order);
2876 goto fail;
2877 }
2878
2879 if (vmap_pages_range(addr, addr + size, prot, area->pages,
2880 page_shift) < 0) {
2881 warn_alloc(gfp_mask, NULL,
2882 "vmalloc error: size %lu, failed to map pages",
2883 area->nr_pages * PAGE_SIZE);
2884 goto fail;
2885 }
2886
2887 return area->addr;
2888
2889fail:
2890 __vfree(area->addr);
2891 return NULL;
2892}
2893
2894/**
2895 * __vmalloc_node_range - allocate virtually contiguous memory
2896 * @size: allocation size
2897 * @align: desired alignment
2898 * @start: vm area range start
2899 * @end: vm area range end
2900 * @gfp_mask: flags for the page level allocator
2901 * @prot: protection mask for the allocated pages
2902 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
2903 * @node: node to use for allocation or NUMA_NO_NODE
2904 * @caller: caller's return address
2905 *
2906 * Allocate enough pages to cover @size from the page level
2907 * allocator with @gfp_mask flags. Map them into contiguous
2908 * kernel virtual space, using a pagetable protection of @prot.
2909 *
2910 * Return: the address of the area or %NULL on failure
2911 */
2912void *__vmalloc_node_range(unsigned long size, unsigned long align,
2913 unsigned long start, unsigned long end, gfp_t gfp_mask,
2914 pgprot_t prot, unsigned long vm_flags, int node,
2915 const void *caller)
2916{
2917 struct vm_struct *area;
2918 void *addr;
2919 unsigned long real_size = size;
2920 unsigned long real_align = align;
2921 unsigned int shift = PAGE_SHIFT;
2922
2923 if (WARN_ON_ONCE(!size))
2924 return NULL;
2925
2926 if ((size >> PAGE_SHIFT) > totalram_pages()) {
2927 warn_alloc(gfp_mask, NULL,
2928 "vmalloc error: size %lu, exceeds total pages",
2929 real_size);
2930 return NULL;
2931 }
2932
2933 if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
2934 unsigned long size_per_node;
2935
2936 /*
2937 * Try huge pages. Only try for PAGE_KERNEL allocations,
2938 * others like modules don't yet expect huge pages in
2939 * their allocations due to apply_to_page_range not
2940 * supporting them.
2941 */
2942
2943 size_per_node = size;
2944 if (node == NUMA_NO_NODE)
2945 size_per_node /= num_online_nodes();
2946 if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
2947 shift = PMD_SHIFT;
2948 else
2949 shift = arch_vmap_pte_supported_shift(size_per_node);
2950
2951 align = max(real_align, 1UL << shift);
2952 size = ALIGN(real_size, 1UL << shift);
2953 }
2954
2955again:
2956 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
2957 VM_UNINITIALIZED | vm_flags, start, end, node,
2958 gfp_mask, caller);
2959 if (!area) {
2960 warn_alloc(gfp_mask, NULL,
2961 "vmalloc error: size %lu, vm_struct allocation failed",
2962 real_size);
2963 goto fail;
2964 }
2965
2966 addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
2967 if (!addr)
2968 goto fail;
2969
2970 /*
2971 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
2972 * flag. It means that vm_struct is not fully initialized.
2973 * Now, it is fully initialized, so remove this flag here.
2974 */
2975 clear_vm_uninitialized_flag(area);
2976
2977 size = PAGE_ALIGN(size);
2978 kmemleak_vmalloc(area, size, gfp_mask);
2979
2980 return addr;
2981
2982fail:
2983 if (shift > PAGE_SHIFT) {
2984 shift = PAGE_SHIFT;
2985 align = real_align;
2986 size = real_size;
2987 goto again;
2988 }
2989
2990 return NULL;
2991}
2992
2993/**
2994 * __vmalloc_node - allocate virtually contiguous memory
2995 * @size: allocation size
2996 * @align: desired alignment
2997 * @gfp_mask: flags for the page level allocator
2998 * @node: node to use for allocation or NUMA_NO_NODE
2999 * @caller: caller's return address
3000 *
3001 * Allocate enough pages to cover @size from the page level allocator with
3002 * @gfp_mask flags. Map them into contiguous kernel virtual space.
3003 *
3004 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
3005 * and __GFP_NOFAIL are not supported
3006 *
3007 * Any use of gfp flags outside of GFP_KERNEL should be consulted
3008 * with mm people.
3009 *
3010 * Return: pointer to the allocated memory or %NULL on error
3011 */
3012void *__vmalloc_node(unsigned long size, unsigned long align,
3013 gfp_t gfp_mask, int node, const void *caller)
3014{
3015 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
3016 gfp_mask, PAGE_KERNEL, 0, node, caller);
3017}
3018/*
3019 * This is only for performance analysis of vmalloc and stress purpose.
3020 * It is required by vmalloc test module, therefore do not use it other
3021 * than that.
3022 */
3023#ifdef CONFIG_TEST_VMALLOC_MODULE
3024EXPORT_SYMBOL_GPL(__vmalloc_node);
3025#endif
3026
3027void *__vmalloc(unsigned long size, gfp_t gfp_mask)
3028{
3029 return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE,
3030 __builtin_return_address(0));
3031}
3032EXPORT_SYMBOL(__vmalloc);
3033
3034/**
3035 * vmalloc - allocate virtually contiguous memory
3036 * @size: allocation size
3037 *
3038 * Allocate enough pages to cover @size from the page level
3039 * allocator and map them into contiguous kernel virtual space.
3040 *
3041 * For tight control over page level allocator and protection flags
3042 * use __vmalloc() instead.
3043 *
3044 * Return: pointer to the allocated memory or %NULL on error
3045 */
3046void *vmalloc(unsigned long size)
3047{
3048 return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE,
3049 __builtin_return_address(0));
3050}
3051EXPORT_SYMBOL(vmalloc);
3052
3053/**
3054 * vmalloc_no_huge - allocate virtually contiguous memory using small pages
3055 * @size: allocation size
3056 *
3057 * Allocate enough non-huge pages to cover @size from the page level
3058 * allocator and map them into contiguous kernel virtual space.
3059 *
3060 * Return: pointer to the allocated memory or %NULL on error
3061 */
3062void *vmalloc_no_huge(unsigned long size)
3063{
3064 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
3065 GFP_KERNEL, PAGE_KERNEL, VM_NO_HUGE_VMAP,
3066 NUMA_NO_NODE, __builtin_return_address(0));
3067}
3068EXPORT_SYMBOL(vmalloc_no_huge);
3069
3070/**
3071 * vzalloc - allocate virtually contiguous memory with zero fill
3072 * @size: allocation size
3073 *
3074 * Allocate enough pages to cover @size from the page level
3075 * allocator and map them into contiguous kernel virtual space.
3076 * The memory allocated is set to zero.
3077 *
3078 * For tight control over page level allocator and protection flags
3079 * use __vmalloc() instead.
3080 *
3081 * Return: pointer to the allocated memory or %NULL on error
3082 */
3083void *vzalloc(unsigned long size)
3084{
3085 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE,
3086 __builtin_return_address(0));
3087}
3088EXPORT_SYMBOL(vzalloc);
3089
3090/**
3091 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
3092 * @size: allocation size
3093 *
3094 * The resulting memory area is zeroed so it can be mapped to userspace
3095 * without leaking data.
3096 *
3097 * Return: pointer to the allocated memory or %NULL on error
3098 */
3099void *vmalloc_user(unsigned long size)
3100{
3101 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3102 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
3103 VM_USERMAP, NUMA_NO_NODE,
3104 __builtin_return_address(0));
3105}
3106EXPORT_SYMBOL(vmalloc_user);
3107
3108/**
3109 * vmalloc_node - allocate memory on a specific node
3110 * @size: allocation size
3111 * @node: numa node
3112 *
3113 * Allocate enough pages to cover @size from the page level
3114 * allocator and map them into contiguous kernel virtual space.
3115 *
3116 * For tight control over page level allocator and protection flags
3117 * use __vmalloc() instead.
3118 *
3119 * Return: pointer to the allocated memory or %NULL on error
3120 */
3121void *vmalloc_node(unsigned long size, int node)
3122{
3123 return __vmalloc_node(size, 1, GFP_KERNEL, node,
3124 __builtin_return_address(0));
3125}
3126EXPORT_SYMBOL(vmalloc_node);
3127
3128/**
3129 * vzalloc_node - allocate memory on a specific node with zero fill
3130 * @size: allocation size
3131 * @node: numa node
3132 *
3133 * Allocate enough pages to cover @size from the page level
3134 * allocator and map them into contiguous kernel virtual space.
3135 * The memory allocated is set to zero.
3136 *
3137 * Return: pointer to the allocated memory or %NULL on error
3138 */
3139void *vzalloc_node(unsigned long size, int node)
3140{
3141 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node,
3142 __builtin_return_address(0));
3143}
3144EXPORT_SYMBOL(vzalloc_node);
3145
3146#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
3147#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3148#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
3149#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
3150#else
3151/*
3152 * 64b systems should always have either DMA or DMA32 zones. For others
3153 * GFP_DMA32 should do the right thing and use the normal zone.
3154 */
3155#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3156#endif
3157
3158/**
3159 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
3160 * @size: allocation size
3161 *
3162 * Allocate enough 32bit PA addressable pages to cover @size from the
3163 * page level allocator and map them into contiguous kernel virtual space.
3164 *
3165 * Return: pointer to the allocated memory or %NULL on error
3166 */
3167void *vmalloc_32(unsigned long size)
3168{
3169 return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE,
3170 __builtin_return_address(0));
3171}
3172EXPORT_SYMBOL(vmalloc_32);
3173
3174/**
3175 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
3176 * @size: allocation size
3177 *
3178 * The resulting memory area is 32bit addressable and zeroed so it can be
3179 * mapped to userspace without leaking data.
3180 *
3181 * Return: pointer to the allocated memory or %NULL on error
3182 */
3183void *vmalloc_32_user(unsigned long size)
3184{
3185 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3186 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
3187 VM_USERMAP, NUMA_NO_NODE,
3188 __builtin_return_address(0));
3189}
3190EXPORT_SYMBOL(vmalloc_32_user);
3191
3192/*
3193 * small helper routine , copy contents to buf from addr.
3194 * If the page is not present, fill zero.
3195 */
3196
3197static int aligned_vread(char *buf, char *addr, unsigned long count)
3198{
3199 struct page *p;
3200 int copied = 0;
3201
3202 while (count) {
3203 unsigned long offset, length;
3204
3205 offset = offset_in_page(addr);
3206 length = PAGE_SIZE - offset;
3207 if (length > count)
3208 length = count;
3209 p = vmalloc_to_page(addr);
3210 /*
3211 * To do safe access to this _mapped_ area, we need
3212 * lock. But adding lock here means that we need to add
3213 * overhead of vmalloc()/vfree() calls for this _debug_
3214 * interface, rarely used. Instead of that, we'll use
3215 * kmap() and get small overhead in this access function.
3216 */
3217 if (p) {
3218 /* We can expect USER0 is not used -- see vread() */
3219 void *map = kmap_atomic(p);
3220 memcpy(buf, map + offset, length);
3221 kunmap_atomic(map);
3222 } else
3223 memset(buf, 0, length);
3224
3225 addr += length;
3226 buf += length;
3227 copied += length;
3228 count -= length;
3229 }
3230 return copied;
3231}
3232
3233/**
3234 * vread() - read vmalloc area in a safe way.
3235 * @buf: buffer for reading data
3236 * @addr: vm address.
3237 * @count: number of bytes to be read.
3238 *
3239 * This function checks that addr is a valid vmalloc'ed area, and
3240 * copy data from that area to a given buffer. If the given memory range
3241 * of [addr...addr+count) includes some valid address, data is copied to
3242 * proper area of @buf. If there are memory holes, they'll be zero-filled.
3243 * IOREMAP area is treated as memory hole and no copy is done.
3244 *
3245 * If [addr...addr+count) doesn't includes any intersects with alive
3246 * vm_struct area, returns 0. @buf should be kernel's buffer.
3247 *
3248 * Note: In usual ops, vread() is never necessary because the caller
3249 * should know vmalloc() area is valid and can use memcpy().
3250 * This is for routines which have to access vmalloc area without
3251 * any information, as /proc/kcore.
3252 *
3253 * Return: number of bytes for which addr and buf should be increased
3254 * (same number as @count) or %0 if [addr...addr+count) doesn't
3255 * include any intersection with valid vmalloc area
3256 */
3257long vread(char *buf, char *addr, unsigned long count)
3258{
3259 struct vmap_area *va;
3260 struct vm_struct *vm;
3261 char *vaddr, *buf_start = buf;
3262 unsigned long buflen = count;
3263 unsigned long n;
3264
3265 /* Don't allow overflow */
3266 if ((unsigned long) addr + count < count)
3267 count = -(unsigned long) addr;
3268
3269 spin_lock(&vmap_area_lock);
3270 va = __find_vmap_area((unsigned long)addr);
3271 if (!va)
3272 goto finished;
3273 list_for_each_entry_from(va, &vmap_area_list, list) {
3274 if (!count)
3275 break;
3276
3277 if (!va->vm)
3278 continue;
3279
3280 vm = va->vm;
3281 vaddr = (char *) vm->addr;
3282 if (addr >= vaddr + get_vm_area_size(vm))
3283 continue;
3284 while (addr < vaddr) {
3285 if (count == 0)
3286 goto finished;
3287 *buf = '\0';
3288 buf++;
3289 addr++;
3290 count--;
3291 }
3292 n = vaddr + get_vm_area_size(vm) - addr;
3293 if (n > count)
3294 n = count;
3295 if (!(vm->flags & VM_IOREMAP))
3296 aligned_vread(buf, addr, n);
3297 else /* IOREMAP area is treated as memory hole */
3298 memset(buf, 0, n);
3299 buf += n;
3300 addr += n;
3301 count -= n;
3302 }
3303finished:
3304 spin_unlock(&vmap_area_lock);
3305
3306 if (buf == buf_start)
3307 return 0;
3308 /* zero-fill memory holes */
3309 if (buf != buf_start + buflen)
3310 memset(buf, 0, buflen - (buf - buf_start));
3311
3312 return buflen;
3313}
3314
3315/**
3316 * remap_vmalloc_range_partial - map vmalloc pages to userspace
3317 * @vma: vma to cover
3318 * @uaddr: target user address to start at
3319 * @kaddr: virtual address of vmalloc kernel memory
3320 * @pgoff: offset from @kaddr to start at
3321 * @size: size of map area
3322 *
3323 * Returns: 0 for success, -Exxx on failure
3324 *
3325 * This function checks that @kaddr is a valid vmalloc'ed area,
3326 * and that it is big enough to cover the range starting at
3327 * @uaddr in @vma. Will return failure if that criteria isn't
3328 * met.
3329 *
3330 * Similar to remap_pfn_range() (see mm/memory.c)
3331 */
3332int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
3333 void *kaddr, unsigned long pgoff,
3334 unsigned long size)
3335{
3336 struct vm_struct *area;
3337 unsigned long off;
3338 unsigned long end_index;
3339
3340 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off))
3341 return -EINVAL;
3342
3343 size = PAGE_ALIGN(size);
3344
3345 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
3346 return -EINVAL;
3347
3348 area = find_vm_area(kaddr);
3349 if (!area)
3350 return -EINVAL;
3351
3352 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
3353 return -EINVAL;
3354
3355 if (check_add_overflow(size, off, &end_index) ||
3356 end_index > get_vm_area_size(area))
3357 return -EINVAL;
3358 kaddr += off;
3359
3360 do {
3361 struct page *page = vmalloc_to_page(kaddr);
3362 int ret;
3363
3364 ret = vm_insert_page(vma, uaddr, page);
3365 if (ret)
3366 return ret;
3367
3368 uaddr += PAGE_SIZE;
3369 kaddr += PAGE_SIZE;
3370 size -= PAGE_SIZE;
3371 } while (size > 0);
3372
3373 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
3374
3375 return 0;
3376}
3377
3378/**
3379 * remap_vmalloc_range - map vmalloc pages to userspace
3380 * @vma: vma to cover (map full range of vma)
3381 * @addr: vmalloc memory
3382 * @pgoff: number of pages into addr before first page to map
3383 *
3384 * Returns: 0 for success, -Exxx on failure
3385 *
3386 * This function checks that addr is a valid vmalloc'ed area, and
3387 * that it is big enough to cover the vma. Will return failure if
3388 * that criteria isn't met.
3389 *
3390 * Similar to remap_pfn_range() (see mm/memory.c)
3391 */
3392int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
3393 unsigned long pgoff)
3394{
3395 return remap_vmalloc_range_partial(vma, vma->vm_start,
3396 addr, pgoff,
3397 vma->vm_end - vma->vm_start);
3398}
3399EXPORT_SYMBOL(remap_vmalloc_range);
3400
3401void free_vm_area(struct vm_struct *area)
3402{
3403 struct vm_struct *ret;
3404 ret = remove_vm_area(area->addr);
3405 BUG_ON(ret != area);
3406 kfree(area);
3407}
3408EXPORT_SYMBOL_GPL(free_vm_area);
3409
3410#ifdef CONFIG_SMP
3411static struct vmap_area *node_to_va(struct rb_node *n)
3412{
3413 return rb_entry_safe(n, struct vmap_area, rb_node);
3414}
3415
3416/**
3417 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
3418 * @addr: target address
3419 *
3420 * Returns: vmap_area if it is found. If there is no such area
3421 * the first highest(reverse order) vmap_area is returned
3422 * i.e. va->va_start < addr && va->va_end < addr or NULL
3423 * if there are no any areas before @addr.
3424 */
3425static struct vmap_area *
3426pvm_find_va_enclose_addr(unsigned long addr)
3427{
3428 struct vmap_area *va, *tmp;
3429 struct rb_node *n;
3430
3431 n = free_vmap_area_root.rb_node;
3432 va = NULL;
3433
3434 while (n) {
3435 tmp = rb_entry(n, struct vmap_area, rb_node);
3436 if (tmp->va_start <= addr) {
3437 va = tmp;
3438 if (tmp->va_end >= addr)
3439 break;
3440
3441 n = n->rb_right;
3442 } else {
3443 n = n->rb_left;
3444 }
3445 }
3446
3447 return va;
3448}
3449
3450/**
3451 * pvm_determine_end_from_reverse - find the highest aligned address
3452 * of free block below VMALLOC_END
3453 * @va:
3454 * in - the VA we start the search(reverse order);
3455 * out - the VA with the highest aligned end address.
3456 * @align: alignment for required highest address
3457 *
3458 * Returns: determined end address within vmap_area
3459 */
3460static unsigned long
3461pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
3462{
3463 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3464 unsigned long addr;
3465
3466 if (likely(*va)) {
3467 list_for_each_entry_from_reverse((*va),
3468 &free_vmap_area_list, list) {
3469 addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
3470 if ((*va)->va_start < addr)
3471 return addr;
3472 }
3473 }
3474
3475 return 0;
3476}
3477
3478/**
3479 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
3480 * @offsets: array containing offset of each area
3481 * @sizes: array containing size of each area
3482 * @nr_vms: the number of areas to allocate
3483 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
3484 *
3485 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
3486 * vm_structs on success, %NULL on failure
3487 *
3488 * Percpu allocator wants to use congruent vm areas so that it can
3489 * maintain the offsets among percpu areas. This function allocates
3490 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
3491 * be scattered pretty far, distance between two areas easily going up
3492 * to gigabytes. To avoid interacting with regular vmallocs, these
3493 * areas are allocated from top.
3494 *
3495 * Despite its complicated look, this allocator is rather simple. It
3496 * does everything top-down and scans free blocks from the end looking
3497 * for matching base. While scanning, if any of the areas do not fit the
3498 * base address is pulled down to fit the area. Scanning is repeated till
3499 * all the areas fit and then all necessary data structures are inserted
3500 * and the result is returned.
3501 */
3502struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
3503 const size_t *sizes, int nr_vms,
3504 size_t align)
3505{
3506 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
3507 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3508 struct vmap_area **vas, *va;
3509 struct vm_struct **vms;
3510 int area, area2, last_area, term_area;
3511 unsigned long base, start, size, end, last_end, orig_start, orig_end;
3512 bool purged = false;
3513 enum fit_type type;
3514
3515 /* verify parameters and allocate data structures */
3516 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
3517 for (last_area = 0, area = 0; area < nr_vms; area++) {
3518 start = offsets[area];
3519 end = start + sizes[area];
3520
3521 /* is everything aligned properly? */
3522 BUG_ON(!IS_ALIGNED(offsets[area], align));
3523 BUG_ON(!IS_ALIGNED(sizes[area], align));
3524
3525 /* detect the area with the highest address */
3526 if (start > offsets[last_area])
3527 last_area = area;
3528
3529 for (area2 = area + 1; area2 < nr_vms; area2++) {
3530 unsigned long start2 = offsets[area2];
3531 unsigned long end2 = start2 + sizes[area2];
3532
3533 BUG_ON(start2 < end && start < end2);
3534 }
3535 }
3536 last_end = offsets[last_area] + sizes[last_area];
3537
3538 if (vmalloc_end - vmalloc_start < last_end) {
3539 WARN_ON(true);
3540 return NULL;
3541 }
3542
3543 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
3544 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
3545 if (!vas || !vms)
3546 goto err_free2;
3547
3548 for (area = 0; area < nr_vms; area++) {
3549 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
3550 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
3551 if (!vas[area] || !vms[area])
3552 goto err_free;
3553 }
3554retry:
3555 spin_lock(&free_vmap_area_lock);
3556
3557 /* start scanning - we scan from the top, begin with the last area */
3558 area = term_area = last_area;
3559 start = offsets[area];
3560 end = start + sizes[area];
3561
3562 va = pvm_find_va_enclose_addr(vmalloc_end);
3563 base = pvm_determine_end_from_reverse(&va, align) - end;
3564
3565 while (true) {
3566 /*
3567 * base might have underflowed, add last_end before
3568 * comparing.
3569 */
3570 if (base + last_end < vmalloc_start + last_end)
3571 goto overflow;
3572
3573 /*
3574 * Fitting base has not been found.
3575 */
3576 if (va == NULL)
3577 goto overflow;
3578
3579 /*
3580 * If required width exceeds current VA block, move
3581 * base downwards and then recheck.
3582 */
3583 if (base + end > va->va_end) {
3584 base = pvm_determine_end_from_reverse(&va, align) - end;
3585 term_area = area;
3586 continue;
3587 }
3588
3589 /*
3590 * If this VA does not fit, move base downwards and recheck.
3591 */
3592 if (base + start < va->va_start) {
3593 va = node_to_va(rb_prev(&va->rb_node));
3594 base = pvm_determine_end_from_reverse(&va, align) - end;
3595 term_area = area;
3596 continue;
3597 }
3598
3599 /*
3600 * This area fits, move on to the previous one. If
3601 * the previous one is the terminal one, we're done.
3602 */
3603 area = (area + nr_vms - 1) % nr_vms;
3604 if (area == term_area)
3605 break;
3606
3607 start = offsets[area];
3608 end = start + sizes[area];
3609 va = pvm_find_va_enclose_addr(base + end);
3610 }
3611
3612 /* we've found a fitting base, insert all va's */
3613 for (area = 0; area < nr_vms; area++) {
3614 int ret;
3615
3616 start = base + offsets[area];
3617 size = sizes[area];
3618
3619 va = pvm_find_va_enclose_addr(start);
3620 if (WARN_ON_ONCE(va == NULL))
3621 /* It is a BUG(), but trigger recovery instead. */
3622 goto recovery;
3623
3624 type = classify_va_fit_type(va, start, size);
3625 if (WARN_ON_ONCE(type == NOTHING_FIT))
3626 /* It is a BUG(), but trigger recovery instead. */
3627 goto recovery;
3628
3629 ret = adjust_va_to_fit_type(va, start, size, type);
3630 if (unlikely(ret))
3631 goto recovery;
3632
3633 /* Allocated area. */
3634 va = vas[area];
3635 va->va_start = start;
3636 va->va_end = start + size;
3637 }
3638
3639 spin_unlock(&free_vmap_area_lock);
3640
3641 /* populate the kasan shadow space */
3642 for (area = 0; area < nr_vms; area++) {
3643 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area]))
3644 goto err_free_shadow;
3645
3646 kasan_unpoison_vmalloc((void *)vas[area]->va_start,
3647 sizes[area]);
3648 }
3649
3650 /* insert all vm's */
3651 spin_lock(&vmap_area_lock);
3652 for (area = 0; area < nr_vms; area++) {
3653 insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list);
3654
3655 setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
3656 pcpu_get_vm_areas);
3657 }
3658 spin_unlock(&vmap_area_lock);
3659
3660 kfree(vas);
3661 return vms;
3662
3663recovery:
3664 /*
3665 * Remove previously allocated areas. There is no
3666 * need in removing these areas from the busy tree,
3667 * because they are inserted only on the final step
3668 * and when pcpu_get_vm_areas() is success.
3669 */
3670 while (area--) {
3671 orig_start = vas[area]->va_start;
3672 orig_end = vas[area]->va_end;
3673 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
3674 &free_vmap_area_list);
3675 if (va)
3676 kasan_release_vmalloc(orig_start, orig_end,
3677 va->va_start, va->va_end);
3678 vas[area] = NULL;
3679 }
3680
3681overflow:
3682 spin_unlock(&free_vmap_area_lock);
3683 if (!purged) {
3684 purge_vmap_area_lazy();
3685 purged = true;
3686
3687 /* Before "retry", check if we recover. */
3688 for (area = 0; area < nr_vms; area++) {
3689 if (vas[area])
3690 continue;
3691
3692 vas[area] = kmem_cache_zalloc(
3693 vmap_area_cachep, GFP_KERNEL);
3694 if (!vas[area])
3695 goto err_free;
3696 }
3697
3698 goto retry;
3699 }
3700
3701err_free:
3702 for (area = 0; area < nr_vms; area++) {
3703 if (vas[area])
3704 kmem_cache_free(vmap_area_cachep, vas[area]);
3705
3706 kfree(vms[area]);
3707 }
3708err_free2:
3709 kfree(vas);
3710 kfree(vms);
3711 return NULL;
3712
3713err_free_shadow:
3714 spin_lock(&free_vmap_area_lock);
3715 /*
3716 * We release all the vmalloc shadows, even the ones for regions that
3717 * hadn't been successfully added. This relies on kasan_release_vmalloc
3718 * being able to tolerate this case.
3719 */
3720 for (area = 0; area < nr_vms; area++) {
3721 orig_start = vas[area]->va_start;
3722 orig_end = vas[area]->va_end;
3723 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
3724 &free_vmap_area_list);
3725 if (va)
3726 kasan_release_vmalloc(orig_start, orig_end,
3727 va->va_start, va->va_end);
3728 vas[area] = NULL;
3729 kfree(vms[area]);
3730 }
3731 spin_unlock(&free_vmap_area_lock);
3732 kfree(vas);
3733 kfree(vms);
3734 return NULL;
3735}
3736
3737/**
3738 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
3739 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
3740 * @nr_vms: the number of allocated areas
3741 *
3742 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
3743 */
3744void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
3745{
3746 int i;
3747
3748 for (i = 0; i < nr_vms; i++)
3749 free_vm_area(vms[i]);
3750 kfree(vms);
3751}
3752#endif /* CONFIG_SMP */
3753
3754#ifdef CONFIG_PRINTK
3755bool vmalloc_dump_obj(void *object)
3756{
3757 struct vm_struct *vm;
3758 void *objp = (void *)PAGE_ALIGN((unsigned long)object);
3759
3760 vm = find_vm_area(objp);
3761 if (!vm)
3762 return false;
3763 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
3764 vm->nr_pages, (unsigned long)vm->addr, vm->caller);
3765 return true;
3766}
3767#endif
3768
3769#ifdef CONFIG_PROC_FS
3770static void *s_start(struct seq_file *m, loff_t *pos)
3771 __acquires(&vmap_purge_lock)
3772 __acquires(&vmap_area_lock)
3773{
3774 mutex_lock(&vmap_purge_lock);
3775 spin_lock(&vmap_area_lock);
3776
3777 return seq_list_start(&vmap_area_list, *pos);
3778}
3779
3780static void *s_next(struct seq_file *m, void *p, loff_t *pos)
3781{
3782 return seq_list_next(p, &vmap_area_list, pos);
3783}
3784
3785static void s_stop(struct seq_file *m, void *p)
3786 __releases(&vmap_area_lock)
3787 __releases(&vmap_purge_lock)
3788{
3789 spin_unlock(&vmap_area_lock);
3790 mutex_unlock(&vmap_purge_lock);
3791}
3792
3793static void show_numa_info(struct seq_file *m, struct vm_struct *v)
3794{
3795 if (IS_ENABLED(CONFIG_NUMA)) {
3796 unsigned int nr, *counters = m->private;
3797
3798 if (!counters)
3799 return;
3800
3801 if (v->flags & VM_UNINITIALIZED)
3802 return;
3803 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
3804 smp_rmb();
3805
3806 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
3807
3808 for (nr = 0; nr < v->nr_pages; nr++)
3809 counters[page_to_nid(v->pages[nr])]++;
3810
3811 for_each_node_state(nr, N_HIGH_MEMORY)
3812 if (counters[nr])
3813 seq_printf(m, " N%u=%u", nr, counters[nr]);
3814 }
3815}
3816
3817static void show_purge_info(struct seq_file *m)
3818{
3819 struct vmap_area *va;
3820
3821 spin_lock(&purge_vmap_area_lock);
3822 list_for_each_entry(va, &purge_vmap_area_list, list) {
3823 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
3824 (void *)va->va_start, (void *)va->va_end,
3825 va->va_end - va->va_start);
3826 }
3827 spin_unlock(&purge_vmap_area_lock);
3828}
3829
3830static int s_show(struct seq_file *m, void *p)
3831{
3832 struct vmap_area *va;
3833 struct vm_struct *v;
3834
3835 va = list_entry(p, struct vmap_area, list);
3836
3837 /*
3838 * s_show can encounter race with remove_vm_area, !vm on behalf
3839 * of vmap area is being tear down or vm_map_ram allocation.
3840 */
3841 if (!va->vm) {
3842 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
3843 (void *)va->va_start, (void *)va->va_end,
3844 va->va_end - va->va_start);
3845
3846 return 0;
3847 }
3848
3849 v = va->vm;
3850
3851 seq_printf(m, "0x%pK-0x%pK %7ld",
3852 v->addr, v->addr + v->size, v->size);
3853
3854 if (v->caller)
3855 seq_printf(m, " %pS", v->caller);
3856
3857 if (v->nr_pages)
3858 seq_printf(m, " pages=%d", v->nr_pages);
3859
3860 if (v->phys_addr)
3861 seq_printf(m, " phys=%pa", &v->phys_addr);
3862
3863 if (v->flags & VM_IOREMAP)
3864 seq_puts(m, " ioremap");
3865
3866 if (v->flags & VM_ALLOC)
3867 seq_puts(m, " vmalloc");
3868
3869 if (v->flags & VM_MAP)
3870 seq_puts(m, " vmap");
3871
3872 if (v->flags & VM_USERMAP)
3873 seq_puts(m, " user");
3874
3875 if (v->flags & VM_DMA_COHERENT)
3876 seq_puts(m, " dma-coherent");
3877
3878 if (is_vmalloc_addr(v->pages))
3879 seq_puts(m, " vpages");
3880
3881 show_numa_info(m, v);
3882 seq_putc(m, '\n');
3883
3884 /*
3885 * As a final step, dump "unpurged" areas.
3886 */
3887 if (list_is_last(&va->list, &vmap_area_list))
3888 show_purge_info(m);
3889
3890 return 0;
3891}
3892
3893static const struct seq_operations vmalloc_op = {
3894 .start = s_start,
3895 .next = s_next,
3896 .stop = s_stop,
3897 .show = s_show,
3898};
3899
3900static int __init proc_vmalloc_init(void)
3901{
3902 if (IS_ENABLED(CONFIG_NUMA))
3903 proc_create_seq_private("vmallocinfo", 0400, NULL,
3904 &vmalloc_op,
3905 nr_node_ids * sizeof(unsigned int), NULL);
3906 else
3907 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
3908 return 0;
3909}
3910module_init(proc_vmalloc_init);
3911
3912#endif