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