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1/*
2 * linux/mm/vmalloc.c
3 *
4 * Copyright (C) 1993 Linus Torvalds
5 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
7 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
8 * Numa awareness, Christoph Lameter, SGI, June 2005
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/debugobjects.h>
22#include <linux/kallsyms.h>
23#include <linux/list.h>
24#include <linux/notifier.h>
25#include <linux/rbtree.h>
26#include <linux/radix-tree.h>
27#include <linux/rcupdate.h>
28#include <linux/pfn.h>
29#include <linux/kmemleak.h>
30#include <linux/atomic.h>
31#include <linux/compiler.h>
32#include <linux/llist.h>
33#include <linux/bitops.h>
34
35#include <linux/uaccess.h>
36#include <asm/tlbflush.h>
37#include <asm/shmparam.h>
38
39#include "internal.h"
40
41struct vfree_deferred {
42 struct llist_head list;
43 struct work_struct wq;
44};
45static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
46
47static void __vunmap(const void *, int);
48
49static void free_work(struct work_struct *w)
50{
51 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
52 struct llist_node *t, *llnode;
53
54 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
55 __vunmap((void *)llnode, 1);
56}
57
58/*** Page table manipulation functions ***/
59
60static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
61{
62 pte_t *pte;
63
64 pte = pte_offset_kernel(pmd, addr);
65 do {
66 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
67 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
68 } while (pte++, addr += PAGE_SIZE, addr != end);
69}
70
71static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
72{
73 pmd_t *pmd;
74 unsigned long next;
75
76 pmd = pmd_offset(pud, addr);
77 do {
78 next = pmd_addr_end(addr, end);
79 if (pmd_clear_huge(pmd))
80 continue;
81 if (pmd_none_or_clear_bad(pmd))
82 continue;
83 vunmap_pte_range(pmd, addr, next);
84 } while (pmd++, addr = next, addr != end);
85}
86
87static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end)
88{
89 pud_t *pud;
90 unsigned long next;
91
92 pud = pud_offset(p4d, addr);
93 do {
94 next = pud_addr_end(addr, end);
95 if (pud_clear_huge(pud))
96 continue;
97 if (pud_none_or_clear_bad(pud))
98 continue;
99 vunmap_pmd_range(pud, addr, next);
100 } while (pud++, addr = next, addr != end);
101}
102
103static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end)
104{
105 p4d_t *p4d;
106 unsigned long next;
107
108 p4d = p4d_offset(pgd, addr);
109 do {
110 next = p4d_addr_end(addr, end);
111 if (p4d_clear_huge(p4d))
112 continue;
113 if (p4d_none_or_clear_bad(p4d))
114 continue;
115 vunmap_pud_range(p4d, addr, next);
116 } while (p4d++, addr = next, addr != end);
117}
118
119static void vunmap_page_range(unsigned long addr, unsigned long end)
120{
121 pgd_t *pgd;
122 unsigned long next;
123
124 BUG_ON(addr >= end);
125 pgd = pgd_offset_k(addr);
126 do {
127 next = pgd_addr_end(addr, end);
128 if (pgd_none_or_clear_bad(pgd))
129 continue;
130 vunmap_p4d_range(pgd, addr, next);
131 } while (pgd++, addr = next, addr != end);
132}
133
134static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
135 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
136{
137 pte_t *pte;
138
139 /*
140 * nr is a running index into the array which helps higher level
141 * callers keep track of where we're up to.
142 */
143
144 pte = pte_alloc_kernel(pmd, addr);
145 if (!pte)
146 return -ENOMEM;
147 do {
148 struct page *page = pages[*nr];
149
150 if (WARN_ON(!pte_none(*pte)))
151 return -EBUSY;
152 if (WARN_ON(!page))
153 return -ENOMEM;
154 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
155 (*nr)++;
156 } while (pte++, addr += PAGE_SIZE, addr != end);
157 return 0;
158}
159
160static int vmap_pmd_range(pud_t *pud, unsigned long addr,
161 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
162{
163 pmd_t *pmd;
164 unsigned long next;
165
166 pmd = pmd_alloc(&init_mm, pud, addr);
167 if (!pmd)
168 return -ENOMEM;
169 do {
170 next = pmd_addr_end(addr, end);
171 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
172 return -ENOMEM;
173 } while (pmd++, addr = next, addr != end);
174 return 0;
175}
176
177static int vmap_pud_range(p4d_t *p4d, unsigned long addr,
178 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
179{
180 pud_t *pud;
181 unsigned long next;
182
183 pud = pud_alloc(&init_mm, p4d, addr);
184 if (!pud)
185 return -ENOMEM;
186 do {
187 next = pud_addr_end(addr, end);
188 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
189 return -ENOMEM;
190 } while (pud++, addr = next, addr != end);
191 return 0;
192}
193
194static int vmap_p4d_range(pgd_t *pgd, unsigned long addr,
195 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
196{
197 p4d_t *p4d;
198 unsigned long next;
199
200 p4d = p4d_alloc(&init_mm, pgd, addr);
201 if (!p4d)
202 return -ENOMEM;
203 do {
204 next = p4d_addr_end(addr, end);
205 if (vmap_pud_range(p4d, addr, next, prot, pages, nr))
206 return -ENOMEM;
207 } while (p4d++, addr = next, addr != end);
208 return 0;
209}
210
211/*
212 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
213 * will have pfns corresponding to the "pages" array.
214 *
215 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
216 */
217static int vmap_page_range_noflush(unsigned long start, unsigned long end,
218 pgprot_t prot, struct page **pages)
219{
220 pgd_t *pgd;
221 unsigned long next;
222 unsigned long addr = start;
223 int err = 0;
224 int nr = 0;
225
226 BUG_ON(addr >= end);
227 pgd = pgd_offset_k(addr);
228 do {
229 next = pgd_addr_end(addr, end);
230 err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr);
231 if (err)
232 return err;
233 } while (pgd++, addr = next, addr != end);
234
235 return nr;
236}
237
238static int vmap_page_range(unsigned long start, unsigned long end,
239 pgprot_t prot, struct page **pages)
240{
241 int ret;
242
243 ret = vmap_page_range_noflush(start, end, prot, pages);
244 flush_cache_vmap(start, end);
245 return ret;
246}
247
248int is_vmalloc_or_module_addr(const void *x)
249{
250 /*
251 * ARM, x86-64 and sparc64 put modules in a special place,
252 * and fall back on vmalloc() if that fails. Others
253 * just put it in the vmalloc space.
254 */
255#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
256 unsigned long addr = (unsigned long)x;
257 if (addr >= MODULES_VADDR && addr < MODULES_END)
258 return 1;
259#endif
260 return is_vmalloc_addr(x);
261}
262
263/*
264 * Walk a vmap address to the struct page it maps.
265 */
266struct page *vmalloc_to_page(const void *vmalloc_addr)
267{
268 unsigned long addr = (unsigned long) vmalloc_addr;
269 struct page *page = NULL;
270 pgd_t *pgd = pgd_offset_k(addr);
271 p4d_t *p4d;
272 pud_t *pud;
273 pmd_t *pmd;
274 pte_t *ptep, pte;
275
276 /*
277 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
278 * architectures that do not vmalloc module space
279 */
280 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
281
282 if (pgd_none(*pgd))
283 return NULL;
284 p4d = p4d_offset(pgd, addr);
285 if (p4d_none(*p4d))
286 return NULL;
287 pud = pud_offset(p4d, addr);
288
289 /*
290 * Don't dereference bad PUD or PMD (below) entries. This will also
291 * identify huge mappings, which we may encounter on architectures
292 * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be
293 * identified as vmalloc addresses by is_vmalloc_addr(), but are
294 * not [unambiguously] associated with a struct page, so there is
295 * no correct value to return for them.
296 */
297 WARN_ON_ONCE(pud_bad(*pud));
298 if (pud_none(*pud) || pud_bad(*pud))
299 return NULL;
300 pmd = pmd_offset(pud, addr);
301 WARN_ON_ONCE(pmd_bad(*pmd));
302 if (pmd_none(*pmd) || pmd_bad(*pmd))
303 return NULL;
304
305 ptep = pte_offset_map(pmd, addr);
306 pte = *ptep;
307 if (pte_present(pte))
308 page = pte_page(pte);
309 pte_unmap(ptep);
310 return page;
311}
312EXPORT_SYMBOL(vmalloc_to_page);
313
314/*
315 * Map a vmalloc()-space virtual address to the physical page frame number.
316 */
317unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
318{
319 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
320}
321EXPORT_SYMBOL(vmalloc_to_pfn);
322
323
324/*** Global kva allocator ***/
325
326#define VM_LAZY_FREE 0x02
327#define VM_VM_AREA 0x04
328
329static DEFINE_SPINLOCK(vmap_area_lock);
330/* Export for kexec only */
331LIST_HEAD(vmap_area_list);
332static LLIST_HEAD(vmap_purge_list);
333static struct rb_root vmap_area_root = RB_ROOT;
334
335/* The vmap cache globals are protected by vmap_area_lock */
336static struct rb_node *free_vmap_cache;
337static unsigned long cached_hole_size;
338static unsigned long cached_vstart;
339static unsigned long cached_align;
340
341static unsigned long vmap_area_pcpu_hole;
342
343static struct vmap_area *__find_vmap_area(unsigned long addr)
344{
345 struct rb_node *n = vmap_area_root.rb_node;
346
347 while (n) {
348 struct vmap_area *va;
349
350 va = rb_entry(n, struct vmap_area, rb_node);
351 if (addr < va->va_start)
352 n = n->rb_left;
353 else if (addr >= va->va_end)
354 n = n->rb_right;
355 else
356 return va;
357 }
358
359 return NULL;
360}
361
362static void __insert_vmap_area(struct vmap_area *va)
363{
364 struct rb_node **p = &vmap_area_root.rb_node;
365 struct rb_node *parent = NULL;
366 struct rb_node *tmp;
367
368 while (*p) {
369 struct vmap_area *tmp_va;
370
371 parent = *p;
372 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
373 if (va->va_start < tmp_va->va_end)
374 p = &(*p)->rb_left;
375 else if (va->va_end > tmp_va->va_start)
376 p = &(*p)->rb_right;
377 else
378 BUG();
379 }
380
381 rb_link_node(&va->rb_node, parent, p);
382 rb_insert_color(&va->rb_node, &vmap_area_root);
383
384 /* address-sort this list */
385 tmp = rb_prev(&va->rb_node);
386 if (tmp) {
387 struct vmap_area *prev;
388 prev = rb_entry(tmp, struct vmap_area, rb_node);
389 list_add_rcu(&va->list, &prev->list);
390 } else
391 list_add_rcu(&va->list, &vmap_area_list);
392}
393
394static void purge_vmap_area_lazy(void);
395
396static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
397
398/*
399 * Allocate a region of KVA of the specified size and alignment, within the
400 * vstart and vend.
401 */
402static struct vmap_area *alloc_vmap_area(unsigned long size,
403 unsigned long align,
404 unsigned long vstart, unsigned long vend,
405 int node, gfp_t gfp_mask)
406{
407 struct vmap_area *va;
408 struct rb_node *n;
409 unsigned long addr;
410 int purged = 0;
411 struct vmap_area *first;
412
413 BUG_ON(!size);
414 BUG_ON(offset_in_page(size));
415 BUG_ON(!is_power_of_2(align));
416
417 might_sleep();
418
419 va = kmalloc_node(sizeof(struct vmap_area),
420 gfp_mask & GFP_RECLAIM_MASK, node);
421 if (unlikely(!va))
422 return ERR_PTR(-ENOMEM);
423
424 /*
425 * Only scan the relevant parts containing pointers to other objects
426 * to avoid false negatives.
427 */
428 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
429
430retry:
431 spin_lock(&vmap_area_lock);
432 /*
433 * Invalidate cache if we have more permissive parameters.
434 * cached_hole_size notes the largest hole noticed _below_
435 * the vmap_area cached in free_vmap_cache: if size fits
436 * into that hole, we want to scan from vstart to reuse
437 * the hole instead of allocating above free_vmap_cache.
438 * Note that __free_vmap_area may update free_vmap_cache
439 * without updating cached_hole_size or cached_align.
440 */
441 if (!free_vmap_cache ||
442 size < cached_hole_size ||
443 vstart < cached_vstart ||
444 align < cached_align) {
445nocache:
446 cached_hole_size = 0;
447 free_vmap_cache = NULL;
448 }
449 /* record if we encounter less permissive parameters */
450 cached_vstart = vstart;
451 cached_align = align;
452
453 /* find starting point for our search */
454 if (free_vmap_cache) {
455 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
456 addr = ALIGN(first->va_end, align);
457 if (addr < vstart)
458 goto nocache;
459 if (addr + size < addr)
460 goto overflow;
461
462 } else {
463 addr = ALIGN(vstart, align);
464 if (addr + size < addr)
465 goto overflow;
466
467 n = vmap_area_root.rb_node;
468 first = NULL;
469
470 while (n) {
471 struct vmap_area *tmp;
472 tmp = rb_entry(n, struct vmap_area, rb_node);
473 if (tmp->va_end >= addr) {
474 first = tmp;
475 if (tmp->va_start <= addr)
476 break;
477 n = n->rb_left;
478 } else
479 n = n->rb_right;
480 }
481
482 if (!first)
483 goto found;
484 }
485
486 /* from the starting point, walk areas until a suitable hole is found */
487 while (addr + size > first->va_start && addr + size <= vend) {
488 if (addr + cached_hole_size < first->va_start)
489 cached_hole_size = first->va_start - addr;
490 addr = ALIGN(first->va_end, align);
491 if (addr + size < addr)
492 goto overflow;
493
494 if (list_is_last(&first->list, &vmap_area_list))
495 goto found;
496
497 first = list_next_entry(first, list);
498 }
499
500found:
501 if (addr + size > vend)
502 goto overflow;
503
504 va->va_start = addr;
505 va->va_end = addr + size;
506 va->flags = 0;
507 __insert_vmap_area(va);
508 free_vmap_cache = &va->rb_node;
509 spin_unlock(&vmap_area_lock);
510
511 BUG_ON(!IS_ALIGNED(va->va_start, align));
512 BUG_ON(va->va_start < vstart);
513 BUG_ON(va->va_end > vend);
514
515 return va;
516
517overflow:
518 spin_unlock(&vmap_area_lock);
519 if (!purged) {
520 purge_vmap_area_lazy();
521 purged = 1;
522 goto retry;
523 }
524
525 if (gfpflags_allow_blocking(gfp_mask)) {
526 unsigned long freed = 0;
527 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
528 if (freed > 0) {
529 purged = 0;
530 goto retry;
531 }
532 }
533
534 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
535 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
536 size);
537 kfree(va);
538 return ERR_PTR(-EBUSY);
539}
540
541int register_vmap_purge_notifier(struct notifier_block *nb)
542{
543 return blocking_notifier_chain_register(&vmap_notify_list, nb);
544}
545EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
546
547int unregister_vmap_purge_notifier(struct notifier_block *nb)
548{
549 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
550}
551EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
552
553static void __free_vmap_area(struct vmap_area *va)
554{
555 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
556
557 if (free_vmap_cache) {
558 if (va->va_end < cached_vstart) {
559 free_vmap_cache = NULL;
560 } else {
561 struct vmap_area *cache;
562 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
563 if (va->va_start <= cache->va_start) {
564 free_vmap_cache = rb_prev(&va->rb_node);
565 /*
566 * We don't try to update cached_hole_size or
567 * cached_align, but it won't go very wrong.
568 */
569 }
570 }
571 }
572 rb_erase(&va->rb_node, &vmap_area_root);
573 RB_CLEAR_NODE(&va->rb_node);
574 list_del_rcu(&va->list);
575
576 /*
577 * Track the highest possible candidate for pcpu area
578 * allocation. Areas outside of vmalloc area can be returned
579 * here too, consider only end addresses which fall inside
580 * vmalloc area proper.
581 */
582 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
583 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
584
585 kfree_rcu(va, rcu_head);
586}
587
588/*
589 * Free a region of KVA allocated by alloc_vmap_area
590 */
591static void free_vmap_area(struct vmap_area *va)
592{
593 spin_lock(&vmap_area_lock);
594 __free_vmap_area(va);
595 spin_unlock(&vmap_area_lock);
596}
597
598/*
599 * Clear the pagetable entries of a given vmap_area
600 */
601static void unmap_vmap_area(struct vmap_area *va)
602{
603 vunmap_page_range(va->va_start, va->va_end);
604}
605
606static void vmap_debug_free_range(unsigned long start, unsigned long end)
607{
608 /*
609 * Unmap page tables and force a TLB flush immediately if pagealloc
610 * debugging is enabled. This catches use after free bugs similarly to
611 * those in linear kernel virtual address space after a page has been
612 * freed.
613 *
614 * All the lazy freeing logic is still retained, in order to minimise
615 * intrusiveness of this debugging feature.
616 *
617 * This is going to be *slow* (linear kernel virtual address debugging
618 * doesn't do a broadcast TLB flush so it is a lot faster).
619 */
620 if (debug_pagealloc_enabled()) {
621 vunmap_page_range(start, end);
622 flush_tlb_kernel_range(start, end);
623 }
624}
625
626/*
627 * lazy_max_pages is the maximum amount of virtual address space we gather up
628 * before attempting to purge with a TLB flush.
629 *
630 * There is a tradeoff here: a larger number will cover more kernel page tables
631 * and take slightly longer to purge, but it will linearly reduce the number of
632 * global TLB flushes that must be performed. It would seem natural to scale
633 * this number up linearly with the number of CPUs (because vmapping activity
634 * could also scale linearly with the number of CPUs), however it is likely
635 * that in practice, workloads might be constrained in other ways that mean
636 * vmap activity will not scale linearly with CPUs. Also, I want to be
637 * conservative and not introduce a big latency on huge systems, so go with
638 * a less aggressive log scale. It will still be an improvement over the old
639 * code, and it will be simple to change the scale factor if we find that it
640 * becomes a problem on bigger systems.
641 */
642static unsigned long lazy_max_pages(void)
643{
644 unsigned int log;
645
646 log = fls(num_online_cpus());
647
648 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
649}
650
651static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
652
653/*
654 * Serialize vmap purging. There is no actual criticial section protected
655 * by this look, but we want to avoid concurrent calls for performance
656 * reasons and to make the pcpu_get_vm_areas more deterministic.
657 */
658static DEFINE_MUTEX(vmap_purge_lock);
659
660/* for per-CPU blocks */
661static void purge_fragmented_blocks_allcpus(void);
662
663/*
664 * called before a call to iounmap() if the caller wants vm_area_struct's
665 * immediately freed.
666 */
667void set_iounmap_nonlazy(void)
668{
669 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
670}
671
672/*
673 * Purges all lazily-freed vmap areas.
674 */
675static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
676{
677 struct llist_node *valist;
678 struct vmap_area *va;
679 struct vmap_area *n_va;
680 bool do_free = false;
681
682 lockdep_assert_held(&vmap_purge_lock);
683
684 valist = llist_del_all(&vmap_purge_list);
685 llist_for_each_entry(va, valist, purge_list) {
686 if (va->va_start < start)
687 start = va->va_start;
688 if (va->va_end > end)
689 end = va->va_end;
690 do_free = true;
691 }
692
693 if (!do_free)
694 return false;
695
696 flush_tlb_kernel_range(start, end);
697
698 spin_lock(&vmap_area_lock);
699 llist_for_each_entry_safe(va, n_va, valist, purge_list) {
700 int nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
701
702 __free_vmap_area(va);
703 atomic_sub(nr, &vmap_lazy_nr);
704 cond_resched_lock(&vmap_area_lock);
705 }
706 spin_unlock(&vmap_area_lock);
707 return true;
708}
709
710/*
711 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
712 * is already purging.
713 */
714static void try_purge_vmap_area_lazy(void)
715{
716 if (mutex_trylock(&vmap_purge_lock)) {
717 __purge_vmap_area_lazy(ULONG_MAX, 0);
718 mutex_unlock(&vmap_purge_lock);
719 }
720}
721
722/*
723 * Kick off a purge of the outstanding lazy areas.
724 */
725static void purge_vmap_area_lazy(void)
726{
727 mutex_lock(&vmap_purge_lock);
728 purge_fragmented_blocks_allcpus();
729 __purge_vmap_area_lazy(ULONG_MAX, 0);
730 mutex_unlock(&vmap_purge_lock);
731}
732
733/*
734 * Free a vmap area, caller ensuring that the area has been unmapped
735 * and flush_cache_vunmap had been called for the correct range
736 * previously.
737 */
738static void free_vmap_area_noflush(struct vmap_area *va)
739{
740 int nr_lazy;
741
742 nr_lazy = atomic_add_return((va->va_end - va->va_start) >> PAGE_SHIFT,
743 &vmap_lazy_nr);
744
745 /* After this point, we may free va at any time */
746 llist_add(&va->purge_list, &vmap_purge_list);
747
748 if (unlikely(nr_lazy > lazy_max_pages()))
749 try_purge_vmap_area_lazy();
750}
751
752/*
753 * Free and unmap a vmap area
754 */
755static void free_unmap_vmap_area(struct vmap_area *va)
756{
757 flush_cache_vunmap(va->va_start, va->va_end);
758 unmap_vmap_area(va);
759 free_vmap_area_noflush(va);
760}
761
762static struct vmap_area *find_vmap_area(unsigned long addr)
763{
764 struct vmap_area *va;
765
766 spin_lock(&vmap_area_lock);
767 va = __find_vmap_area(addr);
768 spin_unlock(&vmap_area_lock);
769
770 return va;
771}
772
773/*** Per cpu kva allocator ***/
774
775/*
776 * vmap space is limited especially on 32 bit architectures. Ensure there is
777 * room for at least 16 percpu vmap blocks per CPU.
778 */
779/*
780 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
781 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
782 * instead (we just need a rough idea)
783 */
784#if BITS_PER_LONG == 32
785#define VMALLOC_SPACE (128UL*1024*1024)
786#else
787#define VMALLOC_SPACE (128UL*1024*1024*1024)
788#endif
789
790#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
791#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
792#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
793#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
794#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
795#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
796#define VMAP_BBMAP_BITS \
797 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
798 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
799 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
800
801#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
802
803static bool vmap_initialized __read_mostly = false;
804
805struct vmap_block_queue {
806 spinlock_t lock;
807 struct list_head free;
808};
809
810struct vmap_block {
811 spinlock_t lock;
812 struct vmap_area *va;
813 unsigned long free, dirty;
814 unsigned long dirty_min, dirty_max; /*< dirty range */
815 struct list_head free_list;
816 struct rcu_head rcu_head;
817 struct list_head purge;
818};
819
820/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
821static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
822
823/*
824 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
825 * in the free path. Could get rid of this if we change the API to return a
826 * "cookie" from alloc, to be passed to free. But no big deal yet.
827 */
828static DEFINE_SPINLOCK(vmap_block_tree_lock);
829static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
830
831/*
832 * We should probably have a fallback mechanism to allocate virtual memory
833 * out of partially filled vmap blocks. However vmap block sizing should be
834 * fairly reasonable according to the vmalloc size, so it shouldn't be a
835 * big problem.
836 */
837
838static unsigned long addr_to_vb_idx(unsigned long addr)
839{
840 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
841 addr /= VMAP_BLOCK_SIZE;
842 return addr;
843}
844
845static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
846{
847 unsigned long addr;
848
849 addr = va_start + (pages_off << PAGE_SHIFT);
850 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
851 return (void *)addr;
852}
853
854/**
855 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
856 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
857 * @order: how many 2^order pages should be occupied in newly allocated block
858 * @gfp_mask: flags for the page level allocator
859 *
860 * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
861 */
862static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
863{
864 struct vmap_block_queue *vbq;
865 struct vmap_block *vb;
866 struct vmap_area *va;
867 unsigned long vb_idx;
868 int node, err;
869 void *vaddr;
870
871 node = numa_node_id();
872
873 vb = kmalloc_node(sizeof(struct vmap_block),
874 gfp_mask & GFP_RECLAIM_MASK, node);
875 if (unlikely(!vb))
876 return ERR_PTR(-ENOMEM);
877
878 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
879 VMALLOC_START, VMALLOC_END,
880 node, gfp_mask);
881 if (IS_ERR(va)) {
882 kfree(vb);
883 return ERR_CAST(va);
884 }
885
886 err = radix_tree_preload(gfp_mask);
887 if (unlikely(err)) {
888 kfree(vb);
889 free_vmap_area(va);
890 return ERR_PTR(err);
891 }
892
893 vaddr = vmap_block_vaddr(va->va_start, 0);
894 spin_lock_init(&vb->lock);
895 vb->va = va;
896 /* At least something should be left free */
897 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
898 vb->free = VMAP_BBMAP_BITS - (1UL << order);
899 vb->dirty = 0;
900 vb->dirty_min = VMAP_BBMAP_BITS;
901 vb->dirty_max = 0;
902 INIT_LIST_HEAD(&vb->free_list);
903
904 vb_idx = addr_to_vb_idx(va->va_start);
905 spin_lock(&vmap_block_tree_lock);
906 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
907 spin_unlock(&vmap_block_tree_lock);
908 BUG_ON(err);
909 radix_tree_preload_end();
910
911 vbq = &get_cpu_var(vmap_block_queue);
912 spin_lock(&vbq->lock);
913 list_add_tail_rcu(&vb->free_list, &vbq->free);
914 spin_unlock(&vbq->lock);
915 put_cpu_var(vmap_block_queue);
916
917 return vaddr;
918}
919
920static void free_vmap_block(struct vmap_block *vb)
921{
922 struct vmap_block *tmp;
923 unsigned long vb_idx;
924
925 vb_idx = addr_to_vb_idx(vb->va->va_start);
926 spin_lock(&vmap_block_tree_lock);
927 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
928 spin_unlock(&vmap_block_tree_lock);
929 BUG_ON(tmp != vb);
930
931 free_vmap_area_noflush(vb->va);
932 kfree_rcu(vb, rcu_head);
933}
934
935static void purge_fragmented_blocks(int cpu)
936{
937 LIST_HEAD(purge);
938 struct vmap_block *vb;
939 struct vmap_block *n_vb;
940 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
941
942 rcu_read_lock();
943 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
944
945 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
946 continue;
947
948 spin_lock(&vb->lock);
949 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
950 vb->free = 0; /* prevent further allocs after releasing lock */
951 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
952 vb->dirty_min = 0;
953 vb->dirty_max = VMAP_BBMAP_BITS;
954 spin_lock(&vbq->lock);
955 list_del_rcu(&vb->free_list);
956 spin_unlock(&vbq->lock);
957 spin_unlock(&vb->lock);
958 list_add_tail(&vb->purge, &purge);
959 } else
960 spin_unlock(&vb->lock);
961 }
962 rcu_read_unlock();
963
964 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
965 list_del(&vb->purge);
966 free_vmap_block(vb);
967 }
968}
969
970static void purge_fragmented_blocks_allcpus(void)
971{
972 int cpu;
973
974 for_each_possible_cpu(cpu)
975 purge_fragmented_blocks(cpu);
976}
977
978static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
979{
980 struct vmap_block_queue *vbq;
981 struct vmap_block *vb;
982 void *vaddr = NULL;
983 unsigned int order;
984
985 BUG_ON(offset_in_page(size));
986 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
987 if (WARN_ON(size == 0)) {
988 /*
989 * Allocating 0 bytes isn't what caller wants since
990 * get_order(0) returns funny result. Just warn and terminate
991 * early.
992 */
993 return NULL;
994 }
995 order = get_order(size);
996
997 rcu_read_lock();
998 vbq = &get_cpu_var(vmap_block_queue);
999 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1000 unsigned long pages_off;
1001
1002 spin_lock(&vb->lock);
1003 if (vb->free < (1UL << order)) {
1004 spin_unlock(&vb->lock);
1005 continue;
1006 }
1007
1008 pages_off = VMAP_BBMAP_BITS - vb->free;
1009 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
1010 vb->free -= 1UL << order;
1011 if (vb->free == 0) {
1012 spin_lock(&vbq->lock);
1013 list_del_rcu(&vb->free_list);
1014 spin_unlock(&vbq->lock);
1015 }
1016
1017 spin_unlock(&vb->lock);
1018 break;
1019 }
1020
1021 put_cpu_var(vmap_block_queue);
1022 rcu_read_unlock();
1023
1024 /* Allocate new block if nothing was found */
1025 if (!vaddr)
1026 vaddr = new_vmap_block(order, gfp_mask);
1027
1028 return vaddr;
1029}
1030
1031static void vb_free(const void *addr, unsigned long size)
1032{
1033 unsigned long offset;
1034 unsigned long vb_idx;
1035 unsigned int order;
1036 struct vmap_block *vb;
1037
1038 BUG_ON(offset_in_page(size));
1039 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
1040
1041 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
1042
1043 order = get_order(size);
1044
1045 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
1046 offset >>= PAGE_SHIFT;
1047
1048 vb_idx = addr_to_vb_idx((unsigned long)addr);
1049 rcu_read_lock();
1050 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
1051 rcu_read_unlock();
1052 BUG_ON(!vb);
1053
1054 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
1055
1056 spin_lock(&vb->lock);
1057
1058 /* Expand dirty range */
1059 vb->dirty_min = min(vb->dirty_min, offset);
1060 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
1061
1062 vb->dirty += 1UL << order;
1063 if (vb->dirty == VMAP_BBMAP_BITS) {
1064 BUG_ON(vb->free);
1065 spin_unlock(&vb->lock);
1066 free_vmap_block(vb);
1067 } else
1068 spin_unlock(&vb->lock);
1069}
1070
1071/**
1072 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1073 *
1074 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1075 * to amortize TLB flushing overheads. What this means is that any page you
1076 * have now, may, in a former life, have been mapped into kernel virtual
1077 * address by the vmap layer and so there might be some CPUs with TLB entries
1078 * still referencing that page (additional to the regular 1:1 kernel mapping).
1079 *
1080 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1081 * be sure that none of the pages we have control over will have any aliases
1082 * from the vmap layer.
1083 */
1084void vm_unmap_aliases(void)
1085{
1086 unsigned long start = ULONG_MAX, end = 0;
1087 int cpu;
1088 int flush = 0;
1089
1090 if (unlikely(!vmap_initialized))
1091 return;
1092
1093 might_sleep();
1094
1095 for_each_possible_cpu(cpu) {
1096 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1097 struct vmap_block *vb;
1098
1099 rcu_read_lock();
1100 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1101 spin_lock(&vb->lock);
1102 if (vb->dirty) {
1103 unsigned long va_start = vb->va->va_start;
1104 unsigned long s, e;
1105
1106 s = va_start + (vb->dirty_min << PAGE_SHIFT);
1107 e = va_start + (vb->dirty_max << PAGE_SHIFT);
1108
1109 start = min(s, start);
1110 end = max(e, end);
1111
1112 flush = 1;
1113 }
1114 spin_unlock(&vb->lock);
1115 }
1116 rcu_read_unlock();
1117 }
1118
1119 mutex_lock(&vmap_purge_lock);
1120 purge_fragmented_blocks_allcpus();
1121 if (!__purge_vmap_area_lazy(start, end) && flush)
1122 flush_tlb_kernel_range(start, end);
1123 mutex_unlock(&vmap_purge_lock);
1124}
1125EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1126
1127/**
1128 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1129 * @mem: the pointer returned by vm_map_ram
1130 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1131 */
1132void vm_unmap_ram(const void *mem, unsigned int count)
1133{
1134 unsigned long size = (unsigned long)count << PAGE_SHIFT;
1135 unsigned long addr = (unsigned long)mem;
1136 struct vmap_area *va;
1137
1138 might_sleep();
1139 BUG_ON(!addr);
1140 BUG_ON(addr < VMALLOC_START);
1141 BUG_ON(addr > VMALLOC_END);
1142 BUG_ON(!PAGE_ALIGNED(addr));
1143
1144 debug_check_no_locks_freed(mem, size);
1145 vmap_debug_free_range(addr, addr+size);
1146
1147 if (likely(count <= VMAP_MAX_ALLOC)) {
1148 vb_free(mem, size);
1149 return;
1150 }
1151
1152 va = find_vmap_area(addr);
1153 BUG_ON(!va);
1154 free_unmap_vmap_area(va);
1155}
1156EXPORT_SYMBOL(vm_unmap_ram);
1157
1158/**
1159 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1160 * @pages: an array of pointers to the pages to be mapped
1161 * @count: number of pages
1162 * @node: prefer to allocate data structures on this node
1163 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1164 *
1165 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
1166 * faster than vmap so it's good. But if you mix long-life and short-life
1167 * objects with vm_map_ram(), it could consume lots of address space through
1168 * fragmentation (especially on a 32bit machine). You could see failures in
1169 * the end. Please use this function for short-lived objects.
1170 *
1171 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1172 */
1173void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1174{
1175 unsigned long size = (unsigned long)count << PAGE_SHIFT;
1176 unsigned long addr;
1177 void *mem;
1178
1179 if (likely(count <= VMAP_MAX_ALLOC)) {
1180 mem = vb_alloc(size, GFP_KERNEL);
1181 if (IS_ERR(mem))
1182 return NULL;
1183 addr = (unsigned long)mem;
1184 } else {
1185 struct vmap_area *va;
1186 va = alloc_vmap_area(size, PAGE_SIZE,
1187 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1188 if (IS_ERR(va))
1189 return NULL;
1190
1191 addr = va->va_start;
1192 mem = (void *)addr;
1193 }
1194 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1195 vm_unmap_ram(mem, count);
1196 return NULL;
1197 }
1198 return mem;
1199}
1200EXPORT_SYMBOL(vm_map_ram);
1201
1202static struct vm_struct *vmlist __initdata;
1203/**
1204 * vm_area_add_early - add vmap area early during boot
1205 * @vm: vm_struct to add
1206 *
1207 * This function is used to add fixed kernel vm area to vmlist before
1208 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1209 * should contain proper values and the other fields should be zero.
1210 *
1211 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1212 */
1213void __init vm_area_add_early(struct vm_struct *vm)
1214{
1215 struct vm_struct *tmp, **p;
1216
1217 BUG_ON(vmap_initialized);
1218 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1219 if (tmp->addr >= vm->addr) {
1220 BUG_ON(tmp->addr < vm->addr + vm->size);
1221 break;
1222 } else
1223 BUG_ON(tmp->addr + tmp->size > vm->addr);
1224 }
1225 vm->next = *p;
1226 *p = vm;
1227}
1228
1229/**
1230 * vm_area_register_early - register vmap area early during boot
1231 * @vm: vm_struct to register
1232 * @align: requested alignment
1233 *
1234 * This function is used to register kernel vm area before
1235 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1236 * proper values on entry and other fields should be zero. On return,
1237 * vm->addr contains the allocated address.
1238 *
1239 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1240 */
1241void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1242{
1243 static size_t vm_init_off __initdata;
1244 unsigned long addr;
1245
1246 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1247 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1248
1249 vm->addr = (void *)addr;
1250
1251 vm_area_add_early(vm);
1252}
1253
1254void __init vmalloc_init(void)
1255{
1256 struct vmap_area *va;
1257 struct vm_struct *tmp;
1258 int i;
1259
1260 for_each_possible_cpu(i) {
1261 struct vmap_block_queue *vbq;
1262 struct vfree_deferred *p;
1263
1264 vbq = &per_cpu(vmap_block_queue, i);
1265 spin_lock_init(&vbq->lock);
1266 INIT_LIST_HEAD(&vbq->free);
1267 p = &per_cpu(vfree_deferred, i);
1268 init_llist_head(&p->list);
1269 INIT_WORK(&p->wq, free_work);
1270 }
1271
1272 /* Import existing vmlist entries. */
1273 for (tmp = vmlist; tmp; tmp = tmp->next) {
1274 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1275 va->flags = VM_VM_AREA;
1276 va->va_start = (unsigned long)tmp->addr;
1277 va->va_end = va->va_start + tmp->size;
1278 va->vm = tmp;
1279 __insert_vmap_area(va);
1280 }
1281
1282 vmap_area_pcpu_hole = VMALLOC_END;
1283
1284 vmap_initialized = true;
1285}
1286
1287/**
1288 * map_kernel_range_noflush - map kernel VM area with the specified pages
1289 * @addr: start of the VM area to map
1290 * @size: size of the VM area to map
1291 * @prot: page protection flags to use
1292 * @pages: pages to map
1293 *
1294 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1295 * specify should have been allocated using get_vm_area() and its
1296 * friends.
1297 *
1298 * NOTE:
1299 * This function does NOT do any cache flushing. The caller is
1300 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1301 * before calling this function.
1302 *
1303 * RETURNS:
1304 * The number of pages mapped on success, -errno on failure.
1305 */
1306int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1307 pgprot_t prot, struct page **pages)
1308{
1309 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1310}
1311
1312/**
1313 * unmap_kernel_range_noflush - unmap kernel VM area
1314 * @addr: start of the VM area to unmap
1315 * @size: size of the VM area to unmap
1316 *
1317 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1318 * specify should have been allocated using get_vm_area() and its
1319 * friends.
1320 *
1321 * NOTE:
1322 * This function does NOT do any cache flushing. The caller is
1323 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1324 * before calling this function and flush_tlb_kernel_range() after.
1325 */
1326void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1327{
1328 vunmap_page_range(addr, addr + size);
1329}
1330EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1331
1332/**
1333 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1334 * @addr: start of the VM area to unmap
1335 * @size: size of the VM area to unmap
1336 *
1337 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1338 * the unmapping and tlb after.
1339 */
1340void unmap_kernel_range(unsigned long addr, unsigned long size)
1341{
1342 unsigned long end = addr + size;
1343
1344 flush_cache_vunmap(addr, end);
1345 vunmap_page_range(addr, end);
1346 flush_tlb_kernel_range(addr, end);
1347}
1348EXPORT_SYMBOL_GPL(unmap_kernel_range);
1349
1350int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
1351{
1352 unsigned long addr = (unsigned long)area->addr;
1353 unsigned long end = addr + get_vm_area_size(area);
1354 int err;
1355
1356 err = vmap_page_range(addr, end, prot, pages);
1357
1358 return err > 0 ? 0 : err;
1359}
1360EXPORT_SYMBOL_GPL(map_vm_area);
1361
1362static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1363 unsigned long flags, const void *caller)
1364{
1365 spin_lock(&vmap_area_lock);
1366 vm->flags = flags;
1367 vm->addr = (void *)va->va_start;
1368 vm->size = va->va_end - va->va_start;
1369 vm->caller = caller;
1370 va->vm = vm;
1371 va->flags |= VM_VM_AREA;
1372 spin_unlock(&vmap_area_lock);
1373}
1374
1375static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1376{
1377 /*
1378 * Before removing VM_UNINITIALIZED,
1379 * we should make sure that vm has proper values.
1380 * Pair with smp_rmb() in show_numa_info().
1381 */
1382 smp_wmb();
1383 vm->flags &= ~VM_UNINITIALIZED;
1384}
1385
1386static struct vm_struct *__get_vm_area_node(unsigned long size,
1387 unsigned long align, unsigned long flags, unsigned long start,
1388 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1389{
1390 struct vmap_area *va;
1391 struct vm_struct *area;
1392
1393 BUG_ON(in_interrupt());
1394 size = PAGE_ALIGN(size);
1395 if (unlikely(!size))
1396 return NULL;
1397
1398 if (flags & VM_IOREMAP)
1399 align = 1ul << clamp_t(int, get_count_order_long(size),
1400 PAGE_SHIFT, IOREMAP_MAX_ORDER);
1401
1402 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1403 if (unlikely(!area))
1404 return NULL;
1405
1406 if (!(flags & VM_NO_GUARD))
1407 size += PAGE_SIZE;
1408
1409 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1410 if (IS_ERR(va)) {
1411 kfree(area);
1412 return NULL;
1413 }
1414
1415 setup_vmalloc_vm(area, va, flags, caller);
1416
1417 return area;
1418}
1419
1420struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1421 unsigned long start, unsigned long end)
1422{
1423 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1424 GFP_KERNEL, __builtin_return_address(0));
1425}
1426EXPORT_SYMBOL_GPL(__get_vm_area);
1427
1428struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1429 unsigned long start, unsigned long end,
1430 const void *caller)
1431{
1432 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1433 GFP_KERNEL, caller);
1434}
1435
1436/**
1437 * get_vm_area - reserve a contiguous kernel virtual area
1438 * @size: size of the area
1439 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1440 *
1441 * Search an area of @size in the kernel virtual mapping area,
1442 * and reserved it for out purposes. Returns the area descriptor
1443 * on success or %NULL on failure.
1444 */
1445struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1446{
1447 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1448 NUMA_NO_NODE, GFP_KERNEL,
1449 __builtin_return_address(0));
1450}
1451
1452struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1453 const void *caller)
1454{
1455 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1456 NUMA_NO_NODE, GFP_KERNEL, caller);
1457}
1458
1459/**
1460 * find_vm_area - find a continuous kernel virtual area
1461 * @addr: base address
1462 *
1463 * Search for the kernel VM area starting at @addr, and return it.
1464 * It is up to the caller to do all required locking to keep the returned
1465 * pointer valid.
1466 */
1467struct vm_struct *find_vm_area(const void *addr)
1468{
1469 struct vmap_area *va;
1470
1471 va = find_vmap_area((unsigned long)addr);
1472 if (va && va->flags & VM_VM_AREA)
1473 return va->vm;
1474
1475 return NULL;
1476}
1477
1478/**
1479 * remove_vm_area - find and remove a continuous kernel virtual area
1480 * @addr: base address
1481 *
1482 * Search for the kernel VM area starting at @addr, and remove it.
1483 * This function returns the found VM area, but using it is NOT safe
1484 * on SMP machines, except for its size or flags.
1485 */
1486struct vm_struct *remove_vm_area(const void *addr)
1487{
1488 struct vmap_area *va;
1489
1490 might_sleep();
1491
1492 va = find_vmap_area((unsigned long)addr);
1493 if (va && va->flags & VM_VM_AREA) {
1494 struct vm_struct *vm = va->vm;
1495
1496 spin_lock(&vmap_area_lock);
1497 va->vm = NULL;
1498 va->flags &= ~VM_VM_AREA;
1499 va->flags |= VM_LAZY_FREE;
1500 spin_unlock(&vmap_area_lock);
1501
1502 vmap_debug_free_range(va->va_start, va->va_end);
1503 kasan_free_shadow(vm);
1504 free_unmap_vmap_area(va);
1505
1506 return vm;
1507 }
1508 return NULL;
1509}
1510
1511static void __vunmap(const void *addr, int deallocate_pages)
1512{
1513 struct vm_struct *area;
1514
1515 if (!addr)
1516 return;
1517
1518 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
1519 addr))
1520 return;
1521
1522 area = remove_vm_area(addr);
1523 if (unlikely(!area)) {
1524 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1525 addr);
1526 return;
1527 }
1528
1529 debug_check_no_locks_freed(addr, get_vm_area_size(area));
1530 debug_check_no_obj_freed(addr, get_vm_area_size(area));
1531
1532 if (deallocate_pages) {
1533 int i;
1534
1535 for (i = 0; i < area->nr_pages; i++) {
1536 struct page *page = area->pages[i];
1537
1538 BUG_ON(!page);
1539 __free_pages(page, 0);
1540 }
1541
1542 kvfree(area->pages);
1543 }
1544
1545 kfree(area);
1546 return;
1547}
1548
1549static inline void __vfree_deferred(const void *addr)
1550{
1551 /*
1552 * Use raw_cpu_ptr() because this can be called from preemptible
1553 * context. Preemption is absolutely fine here, because the llist_add()
1554 * implementation is lockless, so it works even if we are adding to
1555 * nother cpu's list. schedule_work() should be fine with this too.
1556 */
1557 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
1558
1559 if (llist_add((struct llist_node *)addr, &p->list))
1560 schedule_work(&p->wq);
1561}
1562
1563/**
1564 * vfree_atomic - release memory allocated by vmalloc()
1565 * @addr: memory base address
1566 *
1567 * This one is just like vfree() but can be called in any atomic context
1568 * except NMIs.
1569 */
1570void vfree_atomic(const void *addr)
1571{
1572 BUG_ON(in_nmi());
1573
1574 kmemleak_free(addr);
1575
1576 if (!addr)
1577 return;
1578 __vfree_deferred(addr);
1579}
1580
1581/**
1582 * vfree - release memory allocated by vmalloc()
1583 * @addr: memory base address
1584 *
1585 * Free the virtually continuous memory area starting at @addr, as
1586 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1587 * NULL, no operation is performed.
1588 *
1589 * Must not be called in NMI context (strictly speaking, only if we don't
1590 * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
1591 * conventions for vfree() arch-depenedent would be a really bad idea)
1592 *
1593 * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
1594 */
1595void vfree(const void *addr)
1596{
1597 BUG_ON(in_nmi());
1598
1599 kmemleak_free(addr);
1600
1601 if (!addr)
1602 return;
1603 if (unlikely(in_interrupt()))
1604 __vfree_deferred(addr);
1605 else
1606 __vunmap(addr, 1);
1607}
1608EXPORT_SYMBOL(vfree);
1609
1610/**
1611 * vunmap - release virtual mapping obtained by vmap()
1612 * @addr: memory base address
1613 *
1614 * Free the virtually contiguous memory area starting at @addr,
1615 * which was created from the page array passed to vmap().
1616 *
1617 * Must not be called in interrupt context.
1618 */
1619void vunmap(const void *addr)
1620{
1621 BUG_ON(in_interrupt());
1622 might_sleep();
1623 if (addr)
1624 __vunmap(addr, 0);
1625}
1626EXPORT_SYMBOL(vunmap);
1627
1628/**
1629 * vmap - map an array of pages into virtually contiguous space
1630 * @pages: array of page pointers
1631 * @count: number of pages to map
1632 * @flags: vm_area->flags
1633 * @prot: page protection for the mapping
1634 *
1635 * Maps @count pages from @pages into contiguous kernel virtual
1636 * space.
1637 */
1638void *vmap(struct page **pages, unsigned int count,
1639 unsigned long flags, pgprot_t prot)
1640{
1641 struct vm_struct *area;
1642 unsigned long size; /* In bytes */
1643
1644 might_sleep();
1645
1646 if (count > totalram_pages)
1647 return NULL;
1648
1649 size = (unsigned long)count << PAGE_SHIFT;
1650 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
1651 if (!area)
1652 return NULL;
1653
1654 if (map_vm_area(area, prot, pages)) {
1655 vunmap(area->addr);
1656 return NULL;
1657 }
1658
1659 return area->addr;
1660}
1661EXPORT_SYMBOL(vmap);
1662
1663static void *__vmalloc_node(unsigned long size, unsigned long align,
1664 gfp_t gfp_mask, pgprot_t prot,
1665 int node, const void *caller);
1666static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1667 pgprot_t prot, int node)
1668{
1669 struct page **pages;
1670 unsigned int nr_pages, array_size, i;
1671 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1672 const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
1673 const gfp_t highmem_mask = (gfp_mask & (GFP_DMA | GFP_DMA32)) ?
1674 0 :
1675 __GFP_HIGHMEM;
1676
1677 nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
1678 array_size = (nr_pages * sizeof(struct page *));
1679
1680 area->nr_pages = nr_pages;
1681 /* Please note that the recursion is strictly bounded. */
1682 if (array_size > PAGE_SIZE) {
1683 pages = __vmalloc_node(array_size, 1, nested_gfp|highmem_mask,
1684 PAGE_KERNEL, node, area->caller);
1685 } else {
1686 pages = kmalloc_node(array_size, nested_gfp, node);
1687 }
1688 area->pages = pages;
1689 if (!area->pages) {
1690 remove_vm_area(area->addr);
1691 kfree(area);
1692 return NULL;
1693 }
1694
1695 for (i = 0; i < area->nr_pages; i++) {
1696 struct page *page;
1697
1698 if (node == NUMA_NO_NODE)
1699 page = alloc_page(alloc_mask|highmem_mask);
1700 else
1701 page = alloc_pages_node(node, alloc_mask|highmem_mask, 0);
1702
1703 if (unlikely(!page)) {
1704 /* Successfully allocated i pages, free them in __vunmap() */
1705 area->nr_pages = i;
1706 goto fail;
1707 }
1708 area->pages[i] = page;
1709 if (gfpflags_allow_blocking(gfp_mask|highmem_mask))
1710 cond_resched();
1711 }
1712
1713 if (map_vm_area(area, prot, pages))
1714 goto fail;
1715 return area->addr;
1716
1717fail:
1718 warn_alloc(gfp_mask, NULL,
1719 "vmalloc: allocation failure, allocated %ld of %ld bytes",
1720 (area->nr_pages*PAGE_SIZE), area->size);
1721 vfree(area->addr);
1722 return NULL;
1723}
1724
1725/**
1726 * __vmalloc_node_range - allocate virtually contiguous memory
1727 * @size: allocation size
1728 * @align: desired alignment
1729 * @start: vm area range start
1730 * @end: vm area range end
1731 * @gfp_mask: flags for the page level allocator
1732 * @prot: protection mask for the allocated pages
1733 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
1734 * @node: node to use for allocation or NUMA_NO_NODE
1735 * @caller: caller's return address
1736 *
1737 * Allocate enough pages to cover @size from the page level
1738 * allocator with @gfp_mask flags. Map them into contiguous
1739 * kernel virtual space, using a pagetable protection of @prot.
1740 */
1741void *__vmalloc_node_range(unsigned long size, unsigned long align,
1742 unsigned long start, unsigned long end, gfp_t gfp_mask,
1743 pgprot_t prot, unsigned long vm_flags, int node,
1744 const void *caller)
1745{
1746 struct vm_struct *area;
1747 void *addr;
1748 unsigned long real_size = size;
1749
1750 size = PAGE_ALIGN(size);
1751 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1752 goto fail;
1753
1754 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
1755 vm_flags, start, end, node, gfp_mask, caller);
1756 if (!area)
1757 goto fail;
1758
1759 addr = __vmalloc_area_node(area, gfp_mask, prot, node);
1760 if (!addr)
1761 return NULL;
1762
1763 /*
1764 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
1765 * flag. It means that vm_struct is not fully initialized.
1766 * Now, it is fully initialized, so remove this flag here.
1767 */
1768 clear_vm_uninitialized_flag(area);
1769
1770 kmemleak_vmalloc(area, size, gfp_mask);
1771
1772 return addr;
1773
1774fail:
1775 warn_alloc(gfp_mask, NULL,
1776 "vmalloc: allocation failure: %lu bytes", real_size);
1777 return NULL;
1778}
1779
1780/**
1781 * __vmalloc_node - allocate virtually contiguous memory
1782 * @size: allocation size
1783 * @align: desired alignment
1784 * @gfp_mask: flags for the page level allocator
1785 * @prot: protection mask for the allocated pages
1786 * @node: node to use for allocation or NUMA_NO_NODE
1787 * @caller: caller's return address
1788 *
1789 * Allocate enough pages to cover @size from the page level
1790 * allocator with @gfp_mask flags. Map them into contiguous
1791 * kernel virtual space, using a pagetable protection of @prot.
1792 *
1793 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
1794 * and __GFP_NOFAIL are not supported
1795 *
1796 * Any use of gfp flags outside of GFP_KERNEL should be consulted
1797 * with mm people.
1798 *
1799 */
1800static void *__vmalloc_node(unsigned long size, unsigned long align,
1801 gfp_t gfp_mask, pgprot_t prot,
1802 int node, const void *caller)
1803{
1804 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1805 gfp_mask, prot, 0, node, caller);
1806}
1807
1808void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1809{
1810 return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1811 __builtin_return_address(0));
1812}
1813EXPORT_SYMBOL(__vmalloc);
1814
1815static inline void *__vmalloc_node_flags(unsigned long size,
1816 int node, gfp_t flags)
1817{
1818 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1819 node, __builtin_return_address(0));
1820}
1821
1822
1823void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags,
1824 void *caller)
1825{
1826 return __vmalloc_node(size, 1, flags, PAGE_KERNEL, node, caller);
1827}
1828
1829/**
1830 * vmalloc - allocate virtually contiguous memory
1831 * @size: allocation size
1832 * Allocate enough pages to cover @size from the page level
1833 * allocator and map them into contiguous kernel virtual space.
1834 *
1835 * For tight control over page level allocator and protection flags
1836 * use __vmalloc() instead.
1837 */
1838void *vmalloc(unsigned long size)
1839{
1840 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1841 GFP_KERNEL);
1842}
1843EXPORT_SYMBOL(vmalloc);
1844
1845/**
1846 * vzalloc - allocate virtually contiguous memory with zero fill
1847 * @size: allocation size
1848 * Allocate enough pages to cover @size from the page level
1849 * allocator and map them into contiguous kernel virtual space.
1850 * The memory allocated is set to zero.
1851 *
1852 * For tight control over page level allocator and protection flags
1853 * use __vmalloc() instead.
1854 */
1855void *vzalloc(unsigned long size)
1856{
1857 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1858 GFP_KERNEL | __GFP_ZERO);
1859}
1860EXPORT_SYMBOL(vzalloc);
1861
1862/**
1863 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1864 * @size: allocation size
1865 *
1866 * The resulting memory area is zeroed so it can be mapped to userspace
1867 * without leaking data.
1868 */
1869void *vmalloc_user(unsigned long size)
1870{
1871 struct vm_struct *area;
1872 void *ret;
1873
1874 ret = __vmalloc_node(size, SHMLBA,
1875 GFP_KERNEL | __GFP_ZERO,
1876 PAGE_KERNEL, NUMA_NO_NODE,
1877 __builtin_return_address(0));
1878 if (ret) {
1879 area = find_vm_area(ret);
1880 area->flags |= VM_USERMAP;
1881 }
1882 return ret;
1883}
1884EXPORT_SYMBOL(vmalloc_user);
1885
1886/**
1887 * vmalloc_node - allocate memory on a specific node
1888 * @size: allocation size
1889 * @node: numa node
1890 *
1891 * Allocate enough pages to cover @size from the page level
1892 * allocator and map them into contiguous kernel virtual space.
1893 *
1894 * For tight control over page level allocator and protection flags
1895 * use __vmalloc() instead.
1896 */
1897void *vmalloc_node(unsigned long size, int node)
1898{
1899 return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL,
1900 node, __builtin_return_address(0));
1901}
1902EXPORT_SYMBOL(vmalloc_node);
1903
1904/**
1905 * vzalloc_node - allocate memory on a specific node with zero fill
1906 * @size: allocation size
1907 * @node: numa node
1908 *
1909 * Allocate enough pages to cover @size from the page level
1910 * allocator and map them into contiguous kernel virtual space.
1911 * The memory allocated is set to zero.
1912 *
1913 * For tight control over page level allocator and protection flags
1914 * use __vmalloc_node() instead.
1915 */
1916void *vzalloc_node(unsigned long size, int node)
1917{
1918 return __vmalloc_node_flags(size, node,
1919 GFP_KERNEL | __GFP_ZERO);
1920}
1921EXPORT_SYMBOL(vzalloc_node);
1922
1923#ifndef PAGE_KERNEL_EXEC
1924# define PAGE_KERNEL_EXEC PAGE_KERNEL
1925#endif
1926
1927/**
1928 * vmalloc_exec - allocate virtually contiguous, executable memory
1929 * @size: allocation size
1930 *
1931 * Kernel-internal function to allocate enough pages to cover @size
1932 * the page level allocator and map them into contiguous and
1933 * executable kernel virtual space.
1934 *
1935 * For tight control over page level allocator and protection flags
1936 * use __vmalloc() instead.
1937 */
1938
1939void *vmalloc_exec(unsigned long size)
1940{
1941 return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC,
1942 NUMA_NO_NODE, __builtin_return_address(0));
1943}
1944
1945#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1946#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
1947#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1948#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
1949#else
1950/*
1951 * 64b systems should always have either DMA or DMA32 zones. For others
1952 * GFP_DMA32 should do the right thing and use the normal zone.
1953 */
1954#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1955#endif
1956
1957/**
1958 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1959 * @size: allocation size
1960 *
1961 * Allocate enough 32bit PA addressable pages to cover @size from the
1962 * page level allocator and map them into contiguous kernel virtual space.
1963 */
1964void *vmalloc_32(unsigned long size)
1965{
1966 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1967 NUMA_NO_NODE, __builtin_return_address(0));
1968}
1969EXPORT_SYMBOL(vmalloc_32);
1970
1971/**
1972 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1973 * @size: allocation size
1974 *
1975 * The resulting memory area is 32bit addressable and zeroed so it can be
1976 * mapped to userspace without leaking data.
1977 */
1978void *vmalloc_32_user(unsigned long size)
1979{
1980 struct vm_struct *area;
1981 void *ret;
1982
1983 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1984 NUMA_NO_NODE, __builtin_return_address(0));
1985 if (ret) {
1986 area = find_vm_area(ret);
1987 area->flags |= VM_USERMAP;
1988 }
1989 return ret;
1990}
1991EXPORT_SYMBOL(vmalloc_32_user);
1992
1993/*
1994 * small helper routine , copy contents to buf from addr.
1995 * If the page is not present, fill zero.
1996 */
1997
1998static int aligned_vread(char *buf, char *addr, unsigned long count)
1999{
2000 struct page *p;
2001 int copied = 0;
2002
2003 while (count) {
2004 unsigned long offset, length;
2005
2006 offset = offset_in_page(addr);
2007 length = PAGE_SIZE - offset;
2008 if (length > count)
2009 length = count;
2010 p = vmalloc_to_page(addr);
2011 /*
2012 * To do safe access to this _mapped_ area, we need
2013 * lock. But adding lock here means that we need to add
2014 * overhead of vmalloc()/vfree() calles for this _debug_
2015 * interface, rarely used. Instead of that, we'll use
2016 * kmap() and get small overhead in this access function.
2017 */
2018 if (p) {
2019 /*
2020 * we can expect USER0 is not used (see vread/vwrite's
2021 * function description)
2022 */
2023 void *map = kmap_atomic(p);
2024 memcpy(buf, map + offset, length);
2025 kunmap_atomic(map);
2026 } else
2027 memset(buf, 0, length);
2028
2029 addr += length;
2030 buf += length;
2031 copied += length;
2032 count -= length;
2033 }
2034 return copied;
2035}
2036
2037static int aligned_vwrite(char *buf, char *addr, unsigned long count)
2038{
2039 struct page *p;
2040 int copied = 0;
2041
2042 while (count) {
2043 unsigned long offset, length;
2044
2045 offset = offset_in_page(addr);
2046 length = PAGE_SIZE - offset;
2047 if (length > count)
2048 length = count;
2049 p = vmalloc_to_page(addr);
2050 /*
2051 * To do safe access to this _mapped_ area, we need
2052 * lock. But adding lock here means that we need to add
2053 * overhead of vmalloc()/vfree() calles for this _debug_
2054 * interface, rarely used. Instead of that, we'll use
2055 * kmap() and get small overhead in this access function.
2056 */
2057 if (p) {
2058 /*
2059 * we can expect USER0 is not used (see vread/vwrite's
2060 * function description)
2061 */
2062 void *map = kmap_atomic(p);
2063 memcpy(map + offset, buf, length);
2064 kunmap_atomic(map);
2065 }
2066 addr += length;
2067 buf += length;
2068 copied += length;
2069 count -= length;
2070 }
2071 return copied;
2072}
2073
2074/**
2075 * vread() - read vmalloc area in a safe way.
2076 * @buf: buffer for reading data
2077 * @addr: vm address.
2078 * @count: number of bytes to be read.
2079 *
2080 * Returns # of bytes which addr and buf should be increased.
2081 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
2082 * includes any intersect with alive vmalloc area.
2083 *
2084 * This function checks that addr is a valid vmalloc'ed area, and
2085 * copy data from that area to a given buffer. If the given memory range
2086 * of [addr...addr+count) includes some valid address, data is copied to
2087 * proper area of @buf. If there are memory holes, they'll be zero-filled.
2088 * IOREMAP area is treated as memory hole and no copy is done.
2089 *
2090 * If [addr...addr+count) doesn't includes any intersects with alive
2091 * vm_struct area, returns 0. @buf should be kernel's buffer.
2092 *
2093 * Note: In usual ops, vread() is never necessary because the caller
2094 * should know vmalloc() area is valid and can use memcpy().
2095 * This is for routines which have to access vmalloc area without
2096 * any informaion, as /dev/kmem.
2097 *
2098 */
2099
2100long vread(char *buf, char *addr, unsigned long count)
2101{
2102 struct vmap_area *va;
2103 struct vm_struct *vm;
2104 char *vaddr, *buf_start = buf;
2105 unsigned long buflen = count;
2106 unsigned long n;
2107
2108 /* Don't allow overflow */
2109 if ((unsigned long) addr + count < count)
2110 count = -(unsigned long) addr;
2111
2112 spin_lock(&vmap_area_lock);
2113 list_for_each_entry(va, &vmap_area_list, list) {
2114 if (!count)
2115 break;
2116
2117 if (!(va->flags & VM_VM_AREA))
2118 continue;
2119
2120 vm = va->vm;
2121 vaddr = (char *) vm->addr;
2122 if (addr >= vaddr + get_vm_area_size(vm))
2123 continue;
2124 while (addr < vaddr) {
2125 if (count == 0)
2126 goto finished;
2127 *buf = '\0';
2128 buf++;
2129 addr++;
2130 count--;
2131 }
2132 n = vaddr + get_vm_area_size(vm) - addr;
2133 if (n > count)
2134 n = count;
2135 if (!(vm->flags & VM_IOREMAP))
2136 aligned_vread(buf, addr, n);
2137 else /* IOREMAP area is treated as memory hole */
2138 memset(buf, 0, n);
2139 buf += n;
2140 addr += n;
2141 count -= n;
2142 }
2143finished:
2144 spin_unlock(&vmap_area_lock);
2145
2146 if (buf == buf_start)
2147 return 0;
2148 /* zero-fill memory holes */
2149 if (buf != buf_start + buflen)
2150 memset(buf, 0, buflen - (buf - buf_start));
2151
2152 return buflen;
2153}
2154
2155/**
2156 * vwrite() - write vmalloc area in a safe way.
2157 * @buf: buffer for source data
2158 * @addr: vm address.
2159 * @count: number of bytes to be read.
2160 *
2161 * Returns # of bytes which addr and buf should be incresed.
2162 * (same number to @count).
2163 * If [addr...addr+count) doesn't includes any intersect with valid
2164 * vmalloc area, returns 0.
2165 *
2166 * This function checks that addr is a valid vmalloc'ed area, and
2167 * copy data from a buffer to the given addr. If specified range of
2168 * [addr...addr+count) includes some valid address, data is copied from
2169 * proper area of @buf. If there are memory holes, no copy to hole.
2170 * IOREMAP area is treated as memory hole and no copy is done.
2171 *
2172 * If [addr...addr+count) doesn't includes any intersects with alive
2173 * vm_struct area, returns 0. @buf should be kernel's buffer.
2174 *
2175 * Note: In usual ops, vwrite() is never necessary because the caller
2176 * should know vmalloc() area is valid and can use memcpy().
2177 * This is for routines which have to access vmalloc area without
2178 * any informaion, as /dev/kmem.
2179 */
2180
2181long vwrite(char *buf, char *addr, unsigned long count)
2182{
2183 struct vmap_area *va;
2184 struct vm_struct *vm;
2185 char *vaddr;
2186 unsigned long n, buflen;
2187 int copied = 0;
2188
2189 /* Don't allow overflow */
2190 if ((unsigned long) addr + count < count)
2191 count = -(unsigned long) addr;
2192 buflen = count;
2193
2194 spin_lock(&vmap_area_lock);
2195 list_for_each_entry(va, &vmap_area_list, list) {
2196 if (!count)
2197 break;
2198
2199 if (!(va->flags & VM_VM_AREA))
2200 continue;
2201
2202 vm = va->vm;
2203 vaddr = (char *) vm->addr;
2204 if (addr >= vaddr + get_vm_area_size(vm))
2205 continue;
2206 while (addr < vaddr) {
2207 if (count == 0)
2208 goto finished;
2209 buf++;
2210 addr++;
2211 count--;
2212 }
2213 n = vaddr + get_vm_area_size(vm) - addr;
2214 if (n > count)
2215 n = count;
2216 if (!(vm->flags & VM_IOREMAP)) {
2217 aligned_vwrite(buf, addr, n);
2218 copied++;
2219 }
2220 buf += n;
2221 addr += n;
2222 count -= n;
2223 }
2224finished:
2225 spin_unlock(&vmap_area_lock);
2226 if (!copied)
2227 return 0;
2228 return buflen;
2229}
2230
2231/**
2232 * remap_vmalloc_range_partial - map vmalloc pages to userspace
2233 * @vma: vma to cover
2234 * @uaddr: target user address to start at
2235 * @kaddr: virtual address of vmalloc kernel memory
2236 * @size: size of map area
2237 *
2238 * Returns: 0 for success, -Exxx on failure
2239 *
2240 * This function checks that @kaddr is a valid vmalloc'ed area,
2241 * and that it is big enough to cover the range starting at
2242 * @uaddr in @vma. Will return failure if that criteria isn't
2243 * met.
2244 *
2245 * Similar to remap_pfn_range() (see mm/memory.c)
2246 */
2247int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
2248 void *kaddr, unsigned long size)
2249{
2250 struct vm_struct *area;
2251
2252 size = PAGE_ALIGN(size);
2253
2254 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2255 return -EINVAL;
2256
2257 area = find_vm_area(kaddr);
2258 if (!area)
2259 return -EINVAL;
2260
2261 if (!(area->flags & VM_USERMAP))
2262 return -EINVAL;
2263
2264 if (kaddr + size > area->addr + area->size)
2265 return -EINVAL;
2266
2267 do {
2268 struct page *page = vmalloc_to_page(kaddr);
2269 int ret;
2270
2271 ret = vm_insert_page(vma, uaddr, page);
2272 if (ret)
2273 return ret;
2274
2275 uaddr += PAGE_SIZE;
2276 kaddr += PAGE_SIZE;
2277 size -= PAGE_SIZE;
2278 } while (size > 0);
2279
2280 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2281
2282 return 0;
2283}
2284EXPORT_SYMBOL(remap_vmalloc_range_partial);
2285
2286/**
2287 * remap_vmalloc_range - map vmalloc pages to userspace
2288 * @vma: vma to cover (map full range of vma)
2289 * @addr: vmalloc memory
2290 * @pgoff: number of pages into addr before first page to map
2291 *
2292 * Returns: 0 for success, -Exxx on failure
2293 *
2294 * This function checks that addr is a valid vmalloc'ed area, and
2295 * that it is big enough to cover the vma. Will return failure if
2296 * that criteria isn't met.
2297 *
2298 * Similar to remap_pfn_range() (see mm/memory.c)
2299 */
2300int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2301 unsigned long pgoff)
2302{
2303 return remap_vmalloc_range_partial(vma, vma->vm_start,
2304 addr + (pgoff << PAGE_SHIFT),
2305 vma->vm_end - vma->vm_start);
2306}
2307EXPORT_SYMBOL(remap_vmalloc_range);
2308
2309/*
2310 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2311 * have one.
2312 */
2313void __weak vmalloc_sync_all(void)
2314{
2315}
2316
2317
2318static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2319{
2320 pte_t ***p = data;
2321
2322 if (p) {
2323 *(*p) = pte;
2324 (*p)++;
2325 }
2326 return 0;
2327}
2328
2329/**
2330 * alloc_vm_area - allocate a range of kernel address space
2331 * @size: size of the area
2332 * @ptes: returns the PTEs for the address space
2333 *
2334 * Returns: NULL on failure, vm_struct on success
2335 *
2336 * This function reserves a range of kernel address space, and
2337 * allocates pagetables to map that range. No actual mappings
2338 * are created.
2339 *
2340 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2341 * allocated for the VM area are returned.
2342 */
2343struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2344{
2345 struct vm_struct *area;
2346
2347 area = get_vm_area_caller(size, VM_IOREMAP,
2348 __builtin_return_address(0));
2349 if (area == NULL)
2350 return NULL;
2351
2352 /*
2353 * This ensures that page tables are constructed for this region
2354 * of kernel virtual address space and mapped into init_mm.
2355 */
2356 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2357 size, f, ptes ? &ptes : NULL)) {
2358 free_vm_area(area);
2359 return NULL;
2360 }
2361
2362 return area;
2363}
2364EXPORT_SYMBOL_GPL(alloc_vm_area);
2365
2366void free_vm_area(struct vm_struct *area)
2367{
2368 struct vm_struct *ret;
2369 ret = remove_vm_area(area->addr);
2370 BUG_ON(ret != area);
2371 kfree(area);
2372}
2373EXPORT_SYMBOL_GPL(free_vm_area);
2374
2375#ifdef CONFIG_SMP
2376static struct vmap_area *node_to_va(struct rb_node *n)
2377{
2378 return rb_entry_safe(n, struct vmap_area, rb_node);
2379}
2380
2381/**
2382 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2383 * @end: target address
2384 * @pnext: out arg for the next vmap_area
2385 * @pprev: out arg for the previous vmap_area
2386 *
2387 * Returns: %true if either or both of next and prev are found,
2388 * %false if no vmap_area exists
2389 *
2390 * Find vmap_areas end addresses of which enclose @end. ie. if not
2391 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2392 */
2393static bool pvm_find_next_prev(unsigned long end,
2394 struct vmap_area **pnext,
2395 struct vmap_area **pprev)
2396{
2397 struct rb_node *n = vmap_area_root.rb_node;
2398 struct vmap_area *va = NULL;
2399
2400 while (n) {
2401 va = rb_entry(n, struct vmap_area, rb_node);
2402 if (end < va->va_end)
2403 n = n->rb_left;
2404 else if (end > va->va_end)
2405 n = n->rb_right;
2406 else
2407 break;
2408 }
2409
2410 if (!va)
2411 return false;
2412
2413 if (va->va_end > end) {
2414 *pnext = va;
2415 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2416 } else {
2417 *pprev = va;
2418 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2419 }
2420 return true;
2421}
2422
2423/**
2424 * pvm_determine_end - find the highest aligned address between two vmap_areas
2425 * @pnext: in/out arg for the next vmap_area
2426 * @pprev: in/out arg for the previous vmap_area
2427 * @align: alignment
2428 *
2429 * Returns: determined end address
2430 *
2431 * Find the highest aligned address between *@pnext and *@pprev below
2432 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2433 * down address is between the end addresses of the two vmap_areas.
2434 *
2435 * Please note that the address returned by this function may fall
2436 * inside *@pnext vmap_area. The caller is responsible for checking
2437 * that.
2438 */
2439static unsigned long pvm_determine_end(struct vmap_area **pnext,
2440 struct vmap_area **pprev,
2441 unsigned long align)
2442{
2443 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2444 unsigned long addr;
2445
2446 if (*pnext)
2447 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2448 else
2449 addr = vmalloc_end;
2450
2451 while (*pprev && (*pprev)->va_end > addr) {
2452 *pnext = *pprev;
2453 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2454 }
2455
2456 return addr;
2457}
2458
2459/**
2460 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2461 * @offsets: array containing offset of each area
2462 * @sizes: array containing size of each area
2463 * @nr_vms: the number of areas to allocate
2464 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2465 *
2466 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2467 * vm_structs on success, %NULL on failure
2468 *
2469 * Percpu allocator wants to use congruent vm areas so that it can
2470 * maintain the offsets among percpu areas. This function allocates
2471 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2472 * be scattered pretty far, distance between two areas easily going up
2473 * to gigabytes. To avoid interacting with regular vmallocs, these
2474 * areas are allocated from top.
2475 *
2476 * Despite its complicated look, this allocator is rather simple. It
2477 * does everything top-down and scans areas from the end looking for
2478 * matching slot. While scanning, if any of the areas overlaps with
2479 * existing vmap_area, the base address is pulled down to fit the
2480 * area. Scanning is repeated till all the areas fit and then all
2481 * necessary data structures are inserted and the result is returned.
2482 */
2483struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2484 const size_t *sizes, int nr_vms,
2485 size_t align)
2486{
2487 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2488 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2489 struct vmap_area **vas, *prev, *next;
2490 struct vm_struct **vms;
2491 int area, area2, last_area, term_area;
2492 unsigned long base, start, end, last_end;
2493 bool purged = false;
2494
2495 /* verify parameters and allocate data structures */
2496 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
2497 for (last_area = 0, area = 0; area < nr_vms; area++) {
2498 start = offsets[area];
2499 end = start + sizes[area];
2500
2501 /* is everything aligned properly? */
2502 BUG_ON(!IS_ALIGNED(offsets[area], align));
2503 BUG_ON(!IS_ALIGNED(sizes[area], align));
2504
2505 /* detect the area with the highest address */
2506 if (start > offsets[last_area])
2507 last_area = area;
2508
2509 for (area2 = area + 1; area2 < nr_vms; area2++) {
2510 unsigned long start2 = offsets[area2];
2511 unsigned long end2 = start2 + sizes[area2];
2512
2513 BUG_ON(start2 < end && start < end2);
2514 }
2515 }
2516 last_end = offsets[last_area] + sizes[last_area];
2517
2518 if (vmalloc_end - vmalloc_start < last_end) {
2519 WARN_ON(true);
2520 return NULL;
2521 }
2522
2523 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2524 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2525 if (!vas || !vms)
2526 goto err_free2;
2527
2528 for (area = 0; area < nr_vms; area++) {
2529 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2530 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2531 if (!vas[area] || !vms[area])
2532 goto err_free;
2533 }
2534retry:
2535 spin_lock(&vmap_area_lock);
2536
2537 /* start scanning - we scan from the top, begin with the last area */
2538 area = term_area = last_area;
2539 start = offsets[area];
2540 end = start + sizes[area];
2541
2542 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2543 base = vmalloc_end - last_end;
2544 goto found;
2545 }
2546 base = pvm_determine_end(&next, &prev, align) - end;
2547
2548 while (true) {
2549 BUG_ON(next && next->va_end <= base + end);
2550 BUG_ON(prev && prev->va_end > base + end);
2551
2552 /*
2553 * base might have underflowed, add last_end before
2554 * comparing.
2555 */
2556 if (base + last_end < vmalloc_start + last_end) {
2557 spin_unlock(&vmap_area_lock);
2558 if (!purged) {
2559 purge_vmap_area_lazy();
2560 purged = true;
2561 goto retry;
2562 }
2563 goto err_free;
2564 }
2565
2566 /*
2567 * If next overlaps, move base downwards so that it's
2568 * right below next and then recheck.
2569 */
2570 if (next && next->va_start < base + end) {
2571 base = pvm_determine_end(&next, &prev, align) - end;
2572 term_area = area;
2573 continue;
2574 }
2575
2576 /*
2577 * If prev overlaps, shift down next and prev and move
2578 * base so that it's right below new next and then
2579 * recheck.
2580 */
2581 if (prev && prev->va_end > base + start) {
2582 next = prev;
2583 prev = node_to_va(rb_prev(&next->rb_node));
2584 base = pvm_determine_end(&next, &prev, align) - end;
2585 term_area = area;
2586 continue;
2587 }
2588
2589 /*
2590 * This area fits, move on to the previous one. If
2591 * the previous one is the terminal one, we're done.
2592 */
2593 area = (area + nr_vms - 1) % nr_vms;
2594 if (area == term_area)
2595 break;
2596 start = offsets[area];
2597 end = start + sizes[area];
2598 pvm_find_next_prev(base + end, &next, &prev);
2599 }
2600found:
2601 /* we've found a fitting base, insert all va's */
2602 for (area = 0; area < nr_vms; area++) {
2603 struct vmap_area *va = vas[area];
2604
2605 va->va_start = base + offsets[area];
2606 va->va_end = va->va_start + sizes[area];
2607 __insert_vmap_area(va);
2608 }
2609
2610 vmap_area_pcpu_hole = base + offsets[last_area];
2611
2612 spin_unlock(&vmap_area_lock);
2613
2614 /* insert all vm's */
2615 for (area = 0; area < nr_vms; area++)
2616 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2617 pcpu_get_vm_areas);
2618
2619 kfree(vas);
2620 return vms;
2621
2622err_free:
2623 for (area = 0; area < nr_vms; area++) {
2624 kfree(vas[area]);
2625 kfree(vms[area]);
2626 }
2627err_free2:
2628 kfree(vas);
2629 kfree(vms);
2630 return NULL;
2631}
2632
2633/**
2634 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2635 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2636 * @nr_vms: the number of allocated areas
2637 *
2638 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2639 */
2640void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2641{
2642 int i;
2643
2644 for (i = 0; i < nr_vms; i++)
2645 free_vm_area(vms[i]);
2646 kfree(vms);
2647}
2648#endif /* CONFIG_SMP */
2649
2650#ifdef CONFIG_PROC_FS
2651static void *s_start(struct seq_file *m, loff_t *pos)
2652 __acquires(&vmap_area_lock)
2653{
2654 spin_lock(&vmap_area_lock);
2655 return seq_list_start(&vmap_area_list, *pos);
2656}
2657
2658static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2659{
2660 return seq_list_next(p, &vmap_area_list, pos);
2661}
2662
2663static void s_stop(struct seq_file *m, void *p)
2664 __releases(&vmap_area_lock)
2665{
2666 spin_unlock(&vmap_area_lock);
2667}
2668
2669static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2670{
2671 if (IS_ENABLED(CONFIG_NUMA)) {
2672 unsigned int nr, *counters = m->private;
2673
2674 if (!counters)
2675 return;
2676
2677 if (v->flags & VM_UNINITIALIZED)
2678 return;
2679 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
2680 smp_rmb();
2681
2682 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2683
2684 for (nr = 0; nr < v->nr_pages; nr++)
2685 counters[page_to_nid(v->pages[nr])]++;
2686
2687 for_each_node_state(nr, N_HIGH_MEMORY)
2688 if (counters[nr])
2689 seq_printf(m, " N%u=%u", nr, counters[nr]);
2690 }
2691}
2692
2693static int s_show(struct seq_file *m, void *p)
2694{
2695 struct vmap_area *va;
2696 struct vm_struct *v;
2697
2698 va = list_entry(p, struct vmap_area, list);
2699
2700 /*
2701 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
2702 * behalf of vmap area is being tear down or vm_map_ram allocation.
2703 */
2704 if (!(va->flags & VM_VM_AREA)) {
2705 seq_printf(m, "0x%pK-0x%pK %7ld %s\n",
2706 (void *)va->va_start, (void *)va->va_end,
2707 va->va_end - va->va_start,
2708 va->flags & VM_LAZY_FREE ? "unpurged vm_area" : "vm_map_ram");
2709
2710 return 0;
2711 }
2712
2713 v = va->vm;
2714
2715 seq_printf(m, "0x%pK-0x%pK %7ld",
2716 v->addr, v->addr + v->size, v->size);
2717
2718 if (v->caller)
2719 seq_printf(m, " %pS", v->caller);
2720
2721 if (v->nr_pages)
2722 seq_printf(m, " pages=%d", v->nr_pages);
2723
2724 if (v->phys_addr)
2725 seq_printf(m, " phys=%pa", &v->phys_addr);
2726
2727 if (v->flags & VM_IOREMAP)
2728 seq_puts(m, " ioremap");
2729
2730 if (v->flags & VM_ALLOC)
2731 seq_puts(m, " vmalloc");
2732
2733 if (v->flags & VM_MAP)
2734 seq_puts(m, " vmap");
2735
2736 if (v->flags & VM_USERMAP)
2737 seq_puts(m, " user");
2738
2739 if (is_vmalloc_addr(v->pages))
2740 seq_puts(m, " vpages");
2741
2742 show_numa_info(m, v);
2743 seq_putc(m, '\n');
2744 return 0;
2745}
2746
2747static const struct seq_operations vmalloc_op = {
2748 .start = s_start,
2749 .next = s_next,
2750 .stop = s_stop,
2751 .show = s_show,
2752};
2753
2754static int vmalloc_open(struct inode *inode, struct file *file)
2755{
2756 if (IS_ENABLED(CONFIG_NUMA))
2757 return seq_open_private(file, &vmalloc_op,
2758 nr_node_ids * sizeof(unsigned int));
2759 else
2760 return seq_open(file, &vmalloc_op);
2761}
2762
2763static const struct file_operations proc_vmalloc_operations = {
2764 .open = vmalloc_open,
2765 .read = seq_read,
2766 .llseek = seq_lseek,
2767 .release = seq_release_private,
2768};
2769
2770static int __init proc_vmalloc_init(void)
2771{
2772 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2773 return 0;
2774}
2775module_init(proc_vmalloc_init);
2776
2777#endif
2778
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 ioremap_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
321static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
322 pgtbl_mod_mask *mask)
323{
324 pte_t *pte;
325
326 pte = pte_offset_kernel(pmd, addr);
327 do {
328 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
329 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
330 } while (pte++, addr += PAGE_SIZE, addr != end);
331 *mask |= PGTBL_PTE_MODIFIED;
332}
333
334static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
335 pgtbl_mod_mask *mask)
336{
337 pmd_t *pmd;
338 unsigned long next;
339 int cleared;
340
341 pmd = pmd_offset(pud, addr);
342 do {
343 next = pmd_addr_end(addr, end);
344
345 cleared = pmd_clear_huge(pmd);
346 if (cleared || pmd_bad(*pmd))
347 *mask |= PGTBL_PMD_MODIFIED;
348
349 if (cleared)
350 continue;
351 if (pmd_none_or_clear_bad(pmd))
352 continue;
353 vunmap_pte_range(pmd, addr, next, mask);
354
355 cond_resched();
356 } while (pmd++, addr = next, addr != end);
357}
358
359static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
360 pgtbl_mod_mask *mask)
361{
362 pud_t *pud;
363 unsigned long next;
364 int cleared;
365
366 pud = pud_offset(p4d, addr);
367 do {
368 next = pud_addr_end(addr, end);
369
370 cleared = pud_clear_huge(pud);
371 if (cleared || pud_bad(*pud))
372 *mask |= PGTBL_PUD_MODIFIED;
373
374 if (cleared)
375 continue;
376 if (pud_none_or_clear_bad(pud))
377 continue;
378 vunmap_pmd_range(pud, addr, next, mask);
379 } while (pud++, addr = next, addr != end);
380}
381
382static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
383 pgtbl_mod_mask *mask)
384{
385 p4d_t *p4d;
386 unsigned long next;
387
388 p4d = p4d_offset(pgd, addr);
389 do {
390 next = p4d_addr_end(addr, end);
391
392 p4d_clear_huge(p4d);
393 if (p4d_bad(*p4d))
394 *mask |= PGTBL_P4D_MODIFIED;
395
396 if (p4d_none_or_clear_bad(p4d))
397 continue;
398 vunmap_pud_range(p4d, addr, next, mask);
399 } while (p4d++, addr = next, addr != end);
400}
401
402/*
403 * vunmap_range_noflush is similar to vunmap_range, but does not
404 * flush caches or TLBs.
405 *
406 * The caller is responsible for calling flush_cache_vmap() before calling
407 * this function, and flush_tlb_kernel_range after it has returned
408 * successfully (and before the addresses are expected to cause a page fault
409 * or be re-mapped for something else, if TLB flushes are being delayed or
410 * coalesced).
411 *
412 * This is an internal function only. Do not use outside mm/.
413 */
414void __vunmap_range_noflush(unsigned long start, unsigned long end)
415{
416 unsigned long next;
417 pgd_t *pgd;
418 unsigned long addr = start;
419 pgtbl_mod_mask mask = 0;
420
421 BUG_ON(addr >= end);
422 pgd = pgd_offset_k(addr);
423 do {
424 next = pgd_addr_end(addr, end);
425 if (pgd_bad(*pgd))
426 mask |= PGTBL_PGD_MODIFIED;
427 if (pgd_none_or_clear_bad(pgd))
428 continue;
429 vunmap_p4d_range(pgd, addr, next, &mask);
430 } while (pgd++, addr = next, addr != end);
431
432 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
433 arch_sync_kernel_mappings(start, end);
434}
435
436void vunmap_range_noflush(unsigned long start, unsigned long end)
437{
438 kmsan_vunmap_range_noflush(start, end);
439 __vunmap_range_noflush(start, end);
440}
441
442/**
443 * vunmap_range - unmap kernel virtual addresses
444 * @addr: start of the VM area to unmap
445 * @end: end of the VM area to unmap (non-inclusive)
446 *
447 * Clears any present PTEs in the virtual address range, flushes TLBs and
448 * caches. Any subsequent access to the address before it has been re-mapped
449 * is a kernel bug.
450 */
451void vunmap_range(unsigned long addr, unsigned long end)
452{
453 flush_cache_vunmap(addr, end);
454 vunmap_range_noflush(addr, end);
455 flush_tlb_kernel_range(addr, end);
456}
457
458static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
459 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
460 pgtbl_mod_mask *mask)
461{
462 pte_t *pte;
463
464 /*
465 * nr is a running index into the array which helps higher level
466 * callers keep track of where we're up to.
467 */
468
469 pte = pte_alloc_kernel_track(pmd, addr, mask);
470 if (!pte)
471 return -ENOMEM;
472 do {
473 struct page *page = pages[*nr];
474
475 if (WARN_ON(!pte_none(ptep_get(pte))))
476 return -EBUSY;
477 if (WARN_ON(!page))
478 return -ENOMEM;
479 if (WARN_ON(!pfn_valid(page_to_pfn(page))))
480 return -EINVAL;
481
482 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
483 (*nr)++;
484 } while (pte++, addr += PAGE_SIZE, addr != end);
485 *mask |= PGTBL_PTE_MODIFIED;
486 return 0;
487}
488
489static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr,
490 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
491 pgtbl_mod_mask *mask)
492{
493 pmd_t *pmd;
494 unsigned long next;
495
496 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
497 if (!pmd)
498 return -ENOMEM;
499 do {
500 next = pmd_addr_end(addr, end);
501 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask))
502 return -ENOMEM;
503 } while (pmd++, addr = next, addr != end);
504 return 0;
505}
506
507static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr,
508 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
509 pgtbl_mod_mask *mask)
510{
511 pud_t *pud;
512 unsigned long next;
513
514 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
515 if (!pud)
516 return -ENOMEM;
517 do {
518 next = pud_addr_end(addr, end);
519 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask))
520 return -ENOMEM;
521 } while (pud++, addr = next, addr != end);
522 return 0;
523}
524
525static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr,
526 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
527 pgtbl_mod_mask *mask)
528{
529 p4d_t *p4d;
530 unsigned long next;
531
532 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
533 if (!p4d)
534 return -ENOMEM;
535 do {
536 next = p4d_addr_end(addr, end);
537 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask))
538 return -ENOMEM;
539 } while (p4d++, addr = next, addr != end);
540 return 0;
541}
542
543static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
544 pgprot_t prot, struct page **pages)
545{
546 unsigned long start = addr;
547 pgd_t *pgd;
548 unsigned long next;
549 int err = 0;
550 int nr = 0;
551 pgtbl_mod_mask mask = 0;
552
553 BUG_ON(addr >= end);
554 pgd = pgd_offset_k(addr);
555 do {
556 next = pgd_addr_end(addr, end);
557 if (pgd_bad(*pgd))
558 mask |= PGTBL_PGD_MODIFIED;
559 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
560 if (err)
561 return err;
562 } while (pgd++, addr = next, addr != end);
563
564 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
565 arch_sync_kernel_mappings(start, end);
566
567 return 0;
568}
569
570/*
571 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
572 * flush caches.
573 *
574 * The caller is responsible for calling flush_cache_vmap() after this
575 * function returns successfully and before the addresses are accessed.
576 *
577 * This is an internal function only. Do not use outside mm/.
578 */
579int __vmap_pages_range_noflush(unsigned long addr, unsigned long end,
580 pgprot_t prot, struct page **pages, unsigned int page_shift)
581{
582 unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
583
584 WARN_ON(page_shift < PAGE_SHIFT);
585
586 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
587 page_shift == PAGE_SHIFT)
588 return vmap_small_pages_range_noflush(addr, end, prot, pages);
589
590 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
591 int err;
592
593 err = vmap_range_noflush(addr, addr + (1UL << page_shift),
594 page_to_phys(pages[i]), prot,
595 page_shift);
596 if (err)
597 return err;
598
599 addr += 1UL << page_shift;
600 }
601
602 return 0;
603}
604
605int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
606 pgprot_t prot, struct page **pages, unsigned int page_shift)
607{
608 int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages,
609 page_shift);
610
611 if (ret)
612 return ret;
613 return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
614}
615
616/**
617 * vmap_pages_range - map pages to a kernel virtual address
618 * @addr: start of the VM area to map
619 * @end: end of the VM area to map (non-inclusive)
620 * @prot: page protection flags to use
621 * @pages: pages to map (always PAGE_SIZE pages)
622 * @page_shift: maximum shift that the pages may be mapped with, @pages must
623 * be aligned and contiguous up to at least this shift.
624 *
625 * RETURNS:
626 * 0 on success, -errno on failure.
627 */
628static int vmap_pages_range(unsigned long addr, unsigned long end,
629 pgprot_t prot, struct page **pages, unsigned int page_shift)
630{
631 int err;
632
633 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
634 flush_cache_vmap(addr, end);
635 return err;
636}
637
638int is_vmalloc_or_module_addr(const void *x)
639{
640 /*
641 * ARM, x86-64 and sparc64 put modules in a special place,
642 * and fall back on vmalloc() if that fails. Others
643 * just put it in the vmalloc space.
644 */
645#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
646 unsigned long addr = (unsigned long)kasan_reset_tag(x);
647 if (addr >= MODULES_VADDR && addr < MODULES_END)
648 return 1;
649#endif
650 return is_vmalloc_addr(x);
651}
652EXPORT_SYMBOL_GPL(is_vmalloc_or_module_addr);
653
654/*
655 * Walk a vmap address to the struct page it maps. Huge vmap mappings will
656 * return the tail page that corresponds to the base page address, which
657 * matches small vmap mappings.
658 */
659struct page *vmalloc_to_page(const void *vmalloc_addr)
660{
661 unsigned long addr = (unsigned long) vmalloc_addr;
662 struct page *page = NULL;
663 pgd_t *pgd = pgd_offset_k(addr);
664 p4d_t *p4d;
665 pud_t *pud;
666 pmd_t *pmd;
667 pte_t *ptep, pte;
668
669 /*
670 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
671 * architectures that do not vmalloc module space
672 */
673 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
674
675 if (pgd_none(*pgd))
676 return NULL;
677 if (WARN_ON_ONCE(pgd_leaf(*pgd)))
678 return NULL; /* XXX: no allowance for huge pgd */
679 if (WARN_ON_ONCE(pgd_bad(*pgd)))
680 return NULL;
681
682 p4d = p4d_offset(pgd, addr);
683 if (p4d_none(*p4d))
684 return NULL;
685 if (p4d_leaf(*p4d))
686 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
687 if (WARN_ON_ONCE(p4d_bad(*p4d)))
688 return NULL;
689
690 pud = pud_offset(p4d, addr);
691 if (pud_none(*pud))
692 return NULL;
693 if (pud_leaf(*pud))
694 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
695 if (WARN_ON_ONCE(pud_bad(*pud)))
696 return NULL;
697
698 pmd = pmd_offset(pud, addr);
699 if (pmd_none(*pmd))
700 return NULL;
701 if (pmd_leaf(*pmd))
702 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
703 if (WARN_ON_ONCE(pmd_bad(*pmd)))
704 return NULL;
705
706 ptep = pte_offset_kernel(pmd, addr);
707 pte = ptep_get(ptep);
708 if (pte_present(pte))
709 page = pte_page(pte);
710
711 return page;
712}
713EXPORT_SYMBOL(vmalloc_to_page);
714
715/*
716 * Map a vmalloc()-space virtual address to the physical page frame number.
717 */
718unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
719{
720 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
721}
722EXPORT_SYMBOL(vmalloc_to_pfn);
723
724
725/*** Global kva allocator ***/
726
727#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
728#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
729
730
731static DEFINE_SPINLOCK(vmap_area_lock);
732static DEFINE_SPINLOCK(free_vmap_area_lock);
733/* Export for kexec only */
734LIST_HEAD(vmap_area_list);
735static struct rb_root vmap_area_root = RB_ROOT;
736static bool vmap_initialized __read_mostly;
737
738static struct rb_root purge_vmap_area_root = RB_ROOT;
739static LIST_HEAD(purge_vmap_area_list);
740static DEFINE_SPINLOCK(purge_vmap_area_lock);
741
742/*
743 * This kmem_cache is used for vmap_area objects. Instead of
744 * allocating from slab we reuse an object from this cache to
745 * make things faster. Especially in "no edge" splitting of
746 * free block.
747 */
748static struct kmem_cache *vmap_area_cachep;
749
750/*
751 * This linked list is used in pair with free_vmap_area_root.
752 * It gives O(1) access to prev/next to perform fast coalescing.
753 */
754static LIST_HEAD(free_vmap_area_list);
755
756/*
757 * This augment red-black tree represents the free vmap space.
758 * All vmap_area objects in this tree are sorted by va->va_start
759 * address. It is used for allocation and merging when a vmap
760 * object is released.
761 *
762 * Each vmap_area node contains a maximum available free block
763 * of its sub-tree, right or left. Therefore it is possible to
764 * find a lowest match of free area.
765 */
766static struct rb_root free_vmap_area_root = RB_ROOT;
767
768/*
769 * Preload a CPU with one object for "no edge" split case. The
770 * aim is to get rid of allocations from the atomic context, thus
771 * to use more permissive allocation masks.
772 */
773static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
774
775static __always_inline unsigned long
776va_size(struct vmap_area *va)
777{
778 return (va->va_end - va->va_start);
779}
780
781static __always_inline unsigned long
782get_subtree_max_size(struct rb_node *node)
783{
784 struct vmap_area *va;
785
786 va = rb_entry_safe(node, struct vmap_area, rb_node);
787 return va ? va->subtree_max_size : 0;
788}
789
790RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
791 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
792
793static void reclaim_and_purge_vmap_areas(void);
794static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
795static void drain_vmap_area_work(struct work_struct *work);
796static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work);
797
798static atomic_long_t nr_vmalloc_pages;
799
800unsigned long vmalloc_nr_pages(void)
801{
802 return atomic_long_read(&nr_vmalloc_pages);
803}
804
805/* Look up the first VA which satisfies addr < va_end, NULL if none. */
806static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
807{
808 struct vmap_area *va = NULL;
809 struct rb_node *n = vmap_area_root.rb_node;
810
811 addr = (unsigned long)kasan_reset_tag((void *)addr);
812
813 while (n) {
814 struct vmap_area *tmp;
815
816 tmp = rb_entry(n, struct vmap_area, rb_node);
817 if (tmp->va_end > addr) {
818 va = tmp;
819 if (tmp->va_start <= addr)
820 break;
821
822 n = n->rb_left;
823 } else
824 n = n->rb_right;
825 }
826
827 return va;
828}
829
830static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root)
831{
832 struct rb_node *n = root->rb_node;
833
834 addr = (unsigned long)kasan_reset_tag((void *)addr);
835
836 while (n) {
837 struct vmap_area *va;
838
839 va = rb_entry(n, struct vmap_area, rb_node);
840 if (addr < va->va_start)
841 n = n->rb_left;
842 else if (addr >= va->va_end)
843 n = n->rb_right;
844 else
845 return va;
846 }
847
848 return NULL;
849}
850
851/*
852 * This function returns back addresses of parent node
853 * and its left or right link for further processing.
854 *
855 * Otherwise NULL is returned. In that case all further
856 * steps regarding inserting of conflicting overlap range
857 * have to be declined and actually considered as a bug.
858 */
859static __always_inline struct rb_node **
860find_va_links(struct vmap_area *va,
861 struct rb_root *root, struct rb_node *from,
862 struct rb_node **parent)
863{
864 struct vmap_area *tmp_va;
865 struct rb_node **link;
866
867 if (root) {
868 link = &root->rb_node;
869 if (unlikely(!*link)) {
870 *parent = NULL;
871 return link;
872 }
873 } else {
874 link = &from;
875 }
876
877 /*
878 * Go to the bottom of the tree. When we hit the last point
879 * we end up with parent rb_node and correct direction, i name
880 * it link, where the new va->rb_node will be attached to.
881 */
882 do {
883 tmp_va = rb_entry(*link, struct vmap_area, rb_node);
884
885 /*
886 * During the traversal we also do some sanity check.
887 * Trigger the BUG() if there are sides(left/right)
888 * or full overlaps.
889 */
890 if (va->va_end <= tmp_va->va_start)
891 link = &(*link)->rb_left;
892 else if (va->va_start >= tmp_va->va_end)
893 link = &(*link)->rb_right;
894 else {
895 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
896 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
897
898 return NULL;
899 }
900 } while (*link);
901
902 *parent = &tmp_va->rb_node;
903 return link;
904}
905
906static __always_inline struct list_head *
907get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
908{
909 struct list_head *list;
910
911 if (unlikely(!parent))
912 /*
913 * The red-black tree where we try to find VA neighbors
914 * before merging or inserting is empty, i.e. it means
915 * there is no free vmap space. Normally it does not
916 * happen but we handle this case anyway.
917 */
918 return NULL;
919
920 list = &rb_entry(parent, struct vmap_area, rb_node)->list;
921 return (&parent->rb_right == link ? list->next : list);
922}
923
924static __always_inline void
925__link_va(struct vmap_area *va, struct rb_root *root,
926 struct rb_node *parent, struct rb_node **link,
927 struct list_head *head, bool augment)
928{
929 /*
930 * VA is still not in the list, but we can
931 * identify its future previous list_head node.
932 */
933 if (likely(parent)) {
934 head = &rb_entry(parent, struct vmap_area, rb_node)->list;
935 if (&parent->rb_right != link)
936 head = head->prev;
937 }
938
939 /* Insert to the rb-tree */
940 rb_link_node(&va->rb_node, parent, link);
941 if (augment) {
942 /*
943 * Some explanation here. Just perform simple insertion
944 * to the tree. We do not set va->subtree_max_size to
945 * its current size before calling rb_insert_augmented().
946 * It is because we populate the tree from the bottom
947 * to parent levels when the node _is_ in the tree.
948 *
949 * Therefore we set subtree_max_size to zero after insertion,
950 * to let __augment_tree_propagate_from() puts everything to
951 * the correct order later on.
952 */
953 rb_insert_augmented(&va->rb_node,
954 root, &free_vmap_area_rb_augment_cb);
955 va->subtree_max_size = 0;
956 } else {
957 rb_insert_color(&va->rb_node, root);
958 }
959
960 /* Address-sort this list */
961 list_add(&va->list, head);
962}
963
964static __always_inline void
965link_va(struct vmap_area *va, struct rb_root *root,
966 struct rb_node *parent, struct rb_node **link,
967 struct list_head *head)
968{
969 __link_va(va, root, parent, link, head, false);
970}
971
972static __always_inline void
973link_va_augment(struct vmap_area *va, struct rb_root *root,
974 struct rb_node *parent, struct rb_node **link,
975 struct list_head *head)
976{
977 __link_va(va, root, parent, link, head, true);
978}
979
980static __always_inline void
981__unlink_va(struct vmap_area *va, struct rb_root *root, bool augment)
982{
983 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
984 return;
985
986 if (augment)
987 rb_erase_augmented(&va->rb_node,
988 root, &free_vmap_area_rb_augment_cb);
989 else
990 rb_erase(&va->rb_node, root);
991
992 list_del_init(&va->list);
993 RB_CLEAR_NODE(&va->rb_node);
994}
995
996static __always_inline void
997unlink_va(struct vmap_area *va, struct rb_root *root)
998{
999 __unlink_va(va, root, false);
1000}
1001
1002static __always_inline void
1003unlink_va_augment(struct vmap_area *va, struct rb_root *root)
1004{
1005 __unlink_va(va, root, true);
1006}
1007
1008#if DEBUG_AUGMENT_PROPAGATE_CHECK
1009/*
1010 * Gets called when remove the node and rotate.
1011 */
1012static __always_inline unsigned long
1013compute_subtree_max_size(struct vmap_area *va)
1014{
1015 return max3(va_size(va),
1016 get_subtree_max_size(va->rb_node.rb_left),
1017 get_subtree_max_size(va->rb_node.rb_right));
1018}
1019
1020static void
1021augment_tree_propagate_check(void)
1022{
1023 struct vmap_area *va;
1024 unsigned long computed_size;
1025
1026 list_for_each_entry(va, &free_vmap_area_list, list) {
1027 computed_size = compute_subtree_max_size(va);
1028 if (computed_size != va->subtree_max_size)
1029 pr_emerg("tree is corrupted: %lu, %lu\n",
1030 va_size(va), va->subtree_max_size);
1031 }
1032}
1033#endif
1034
1035/*
1036 * This function populates subtree_max_size from bottom to upper
1037 * levels starting from VA point. The propagation must be done
1038 * when VA size is modified by changing its va_start/va_end. Or
1039 * in case of newly inserting of VA to the tree.
1040 *
1041 * It means that __augment_tree_propagate_from() must be called:
1042 * - After VA has been inserted to the tree(free path);
1043 * - After VA has been shrunk(allocation path);
1044 * - After VA has been increased(merging path).
1045 *
1046 * Please note that, it does not mean that upper parent nodes
1047 * and their subtree_max_size are recalculated all the time up
1048 * to the root node.
1049 *
1050 * 4--8
1051 * /\
1052 * / \
1053 * / \
1054 * 2--2 8--8
1055 *
1056 * For example if we modify the node 4, shrinking it to 2, then
1057 * no any modification is required. If we shrink the node 2 to 1
1058 * its subtree_max_size is updated only, and set to 1. If we shrink
1059 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
1060 * node becomes 4--6.
1061 */
1062static __always_inline void
1063augment_tree_propagate_from(struct vmap_area *va)
1064{
1065 /*
1066 * Populate the tree from bottom towards the root until
1067 * the calculated maximum available size of checked node
1068 * is equal to its current one.
1069 */
1070 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL);
1071
1072#if DEBUG_AUGMENT_PROPAGATE_CHECK
1073 augment_tree_propagate_check();
1074#endif
1075}
1076
1077static void
1078insert_vmap_area(struct vmap_area *va,
1079 struct rb_root *root, struct list_head *head)
1080{
1081 struct rb_node **link;
1082 struct rb_node *parent;
1083
1084 link = find_va_links(va, root, NULL, &parent);
1085 if (link)
1086 link_va(va, root, parent, link, head);
1087}
1088
1089static void
1090insert_vmap_area_augment(struct vmap_area *va,
1091 struct rb_node *from, struct rb_root *root,
1092 struct list_head *head)
1093{
1094 struct rb_node **link;
1095 struct rb_node *parent;
1096
1097 if (from)
1098 link = find_va_links(va, NULL, from, &parent);
1099 else
1100 link = find_va_links(va, root, NULL, &parent);
1101
1102 if (link) {
1103 link_va_augment(va, root, parent, link, head);
1104 augment_tree_propagate_from(va);
1105 }
1106}
1107
1108/*
1109 * Merge de-allocated chunk of VA memory with previous
1110 * and next free blocks. If coalesce is not done a new
1111 * free area is inserted. If VA has been merged, it is
1112 * freed.
1113 *
1114 * Please note, it can return NULL in case of overlap
1115 * ranges, followed by WARN() report. Despite it is a
1116 * buggy behaviour, a system can be alive and keep
1117 * ongoing.
1118 */
1119static __always_inline struct vmap_area *
1120__merge_or_add_vmap_area(struct vmap_area *va,
1121 struct rb_root *root, struct list_head *head, bool augment)
1122{
1123 struct vmap_area *sibling;
1124 struct list_head *next;
1125 struct rb_node **link;
1126 struct rb_node *parent;
1127 bool merged = false;
1128
1129 /*
1130 * Find a place in the tree where VA potentially will be
1131 * inserted, unless it is merged with its sibling/siblings.
1132 */
1133 link = find_va_links(va, root, NULL, &parent);
1134 if (!link)
1135 return NULL;
1136
1137 /*
1138 * Get next node of VA to check if merging can be done.
1139 */
1140 next = get_va_next_sibling(parent, link);
1141 if (unlikely(next == NULL))
1142 goto insert;
1143
1144 /*
1145 * start end
1146 * | |
1147 * |<------VA------>|<-----Next----->|
1148 * | |
1149 * start end
1150 */
1151 if (next != head) {
1152 sibling = list_entry(next, struct vmap_area, list);
1153 if (sibling->va_start == va->va_end) {
1154 sibling->va_start = va->va_start;
1155
1156 /* Free vmap_area object. */
1157 kmem_cache_free(vmap_area_cachep, va);
1158
1159 /* Point to the new merged area. */
1160 va = sibling;
1161 merged = true;
1162 }
1163 }
1164
1165 /*
1166 * start end
1167 * | |
1168 * |<-----Prev----->|<------VA------>|
1169 * | |
1170 * start end
1171 */
1172 if (next->prev != head) {
1173 sibling = list_entry(next->prev, struct vmap_area, list);
1174 if (sibling->va_end == va->va_start) {
1175 /*
1176 * If both neighbors are coalesced, it is important
1177 * to unlink the "next" node first, followed by merging
1178 * with "previous" one. Otherwise the tree might not be
1179 * fully populated if a sibling's augmented value is
1180 * "normalized" because of rotation operations.
1181 */
1182 if (merged)
1183 __unlink_va(va, root, augment);
1184
1185 sibling->va_end = va->va_end;
1186
1187 /* Free vmap_area object. */
1188 kmem_cache_free(vmap_area_cachep, va);
1189
1190 /* Point to the new merged area. */
1191 va = sibling;
1192 merged = true;
1193 }
1194 }
1195
1196insert:
1197 if (!merged)
1198 __link_va(va, root, parent, link, head, augment);
1199
1200 return va;
1201}
1202
1203static __always_inline struct vmap_area *
1204merge_or_add_vmap_area(struct vmap_area *va,
1205 struct rb_root *root, struct list_head *head)
1206{
1207 return __merge_or_add_vmap_area(va, root, head, false);
1208}
1209
1210static __always_inline struct vmap_area *
1211merge_or_add_vmap_area_augment(struct vmap_area *va,
1212 struct rb_root *root, struct list_head *head)
1213{
1214 va = __merge_or_add_vmap_area(va, root, head, true);
1215 if (va)
1216 augment_tree_propagate_from(va);
1217
1218 return va;
1219}
1220
1221static __always_inline bool
1222is_within_this_va(struct vmap_area *va, unsigned long size,
1223 unsigned long align, unsigned long vstart)
1224{
1225 unsigned long nva_start_addr;
1226
1227 if (va->va_start > vstart)
1228 nva_start_addr = ALIGN(va->va_start, align);
1229 else
1230 nva_start_addr = ALIGN(vstart, align);
1231
1232 /* Can be overflowed due to big size or alignment. */
1233 if (nva_start_addr + size < nva_start_addr ||
1234 nva_start_addr < vstart)
1235 return false;
1236
1237 return (nva_start_addr + size <= va->va_end);
1238}
1239
1240/*
1241 * Find the first free block(lowest start address) in the tree,
1242 * that will accomplish the request corresponding to passing
1243 * parameters. Please note, with an alignment bigger than PAGE_SIZE,
1244 * a search length is adjusted to account for worst case alignment
1245 * overhead.
1246 */
1247static __always_inline struct vmap_area *
1248find_vmap_lowest_match(struct rb_root *root, unsigned long size,
1249 unsigned long align, unsigned long vstart, bool adjust_search_size)
1250{
1251 struct vmap_area *va;
1252 struct rb_node *node;
1253 unsigned long length;
1254
1255 /* Start from the root. */
1256 node = root->rb_node;
1257
1258 /* Adjust the search size for alignment overhead. */
1259 length = adjust_search_size ? size + align - 1 : size;
1260
1261 while (node) {
1262 va = rb_entry(node, struct vmap_area, rb_node);
1263
1264 if (get_subtree_max_size(node->rb_left) >= length &&
1265 vstart < va->va_start) {
1266 node = node->rb_left;
1267 } else {
1268 if (is_within_this_va(va, size, align, vstart))
1269 return va;
1270
1271 /*
1272 * Does not make sense to go deeper towards the right
1273 * sub-tree if it does not have a free block that is
1274 * equal or bigger to the requested search length.
1275 */
1276 if (get_subtree_max_size(node->rb_right) >= length) {
1277 node = node->rb_right;
1278 continue;
1279 }
1280
1281 /*
1282 * OK. We roll back and find the first right sub-tree,
1283 * that will satisfy the search criteria. It can happen
1284 * due to "vstart" restriction or an alignment overhead
1285 * that is bigger then PAGE_SIZE.
1286 */
1287 while ((node = rb_parent(node))) {
1288 va = rb_entry(node, struct vmap_area, rb_node);
1289 if (is_within_this_va(va, size, align, vstart))
1290 return va;
1291
1292 if (get_subtree_max_size(node->rb_right) >= length &&
1293 vstart <= va->va_start) {
1294 /*
1295 * Shift the vstart forward. Please note, we update it with
1296 * parent's start address adding "1" because we do not want
1297 * to enter same sub-tree after it has already been checked
1298 * and no suitable free block found there.
1299 */
1300 vstart = va->va_start + 1;
1301 node = node->rb_right;
1302 break;
1303 }
1304 }
1305 }
1306 }
1307
1308 return NULL;
1309}
1310
1311#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1312#include <linux/random.h>
1313
1314static struct vmap_area *
1315find_vmap_lowest_linear_match(struct list_head *head, unsigned long size,
1316 unsigned long align, unsigned long vstart)
1317{
1318 struct vmap_area *va;
1319
1320 list_for_each_entry(va, head, list) {
1321 if (!is_within_this_va(va, size, align, vstart))
1322 continue;
1323
1324 return va;
1325 }
1326
1327 return NULL;
1328}
1329
1330static void
1331find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head,
1332 unsigned long size, unsigned long align)
1333{
1334 struct vmap_area *va_1, *va_2;
1335 unsigned long vstart;
1336 unsigned int rnd;
1337
1338 get_random_bytes(&rnd, sizeof(rnd));
1339 vstart = VMALLOC_START + rnd;
1340
1341 va_1 = find_vmap_lowest_match(root, size, align, vstart, false);
1342 va_2 = find_vmap_lowest_linear_match(head, size, align, vstart);
1343
1344 if (va_1 != va_2)
1345 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
1346 va_1, va_2, vstart);
1347}
1348#endif
1349
1350enum fit_type {
1351 NOTHING_FIT = 0,
1352 FL_FIT_TYPE = 1, /* full fit */
1353 LE_FIT_TYPE = 2, /* left edge fit */
1354 RE_FIT_TYPE = 3, /* right edge fit */
1355 NE_FIT_TYPE = 4 /* no edge fit */
1356};
1357
1358static __always_inline enum fit_type
1359classify_va_fit_type(struct vmap_area *va,
1360 unsigned long nva_start_addr, unsigned long size)
1361{
1362 enum fit_type type;
1363
1364 /* Check if it is within VA. */
1365 if (nva_start_addr < va->va_start ||
1366 nva_start_addr + size > va->va_end)
1367 return NOTHING_FIT;
1368
1369 /* Now classify. */
1370 if (va->va_start == nva_start_addr) {
1371 if (va->va_end == nva_start_addr + size)
1372 type = FL_FIT_TYPE;
1373 else
1374 type = LE_FIT_TYPE;
1375 } else if (va->va_end == nva_start_addr + size) {
1376 type = RE_FIT_TYPE;
1377 } else {
1378 type = NE_FIT_TYPE;
1379 }
1380
1381 return type;
1382}
1383
1384static __always_inline int
1385adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
1386 struct vmap_area *va, unsigned long nva_start_addr,
1387 unsigned long size)
1388{
1389 struct vmap_area *lva = NULL;
1390 enum fit_type type = classify_va_fit_type(va, nva_start_addr, size);
1391
1392 if (type == FL_FIT_TYPE) {
1393 /*
1394 * No need to split VA, it fully fits.
1395 *
1396 * | |
1397 * V NVA V
1398 * |---------------|
1399 */
1400 unlink_va_augment(va, root);
1401 kmem_cache_free(vmap_area_cachep, va);
1402 } else if (type == LE_FIT_TYPE) {
1403 /*
1404 * Split left edge of fit VA.
1405 *
1406 * | |
1407 * V NVA V R
1408 * |-------|-------|
1409 */
1410 va->va_start += size;
1411 } else if (type == RE_FIT_TYPE) {
1412 /*
1413 * Split right edge of fit VA.
1414 *
1415 * | |
1416 * L V NVA V
1417 * |-------|-------|
1418 */
1419 va->va_end = nva_start_addr;
1420 } else if (type == NE_FIT_TYPE) {
1421 /*
1422 * Split no edge of fit VA.
1423 *
1424 * | |
1425 * L V NVA V R
1426 * |---|-------|---|
1427 */
1428 lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
1429 if (unlikely(!lva)) {
1430 /*
1431 * For percpu allocator we do not do any pre-allocation
1432 * and leave it as it is. The reason is it most likely
1433 * never ends up with NE_FIT_TYPE splitting. In case of
1434 * percpu allocations offsets and sizes are aligned to
1435 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
1436 * are its main fitting cases.
1437 *
1438 * There are a few exceptions though, as an example it is
1439 * a first allocation (early boot up) when we have "one"
1440 * big free space that has to be split.
1441 *
1442 * Also we can hit this path in case of regular "vmap"
1443 * allocations, if "this" current CPU was not preloaded.
1444 * See the comment in alloc_vmap_area() why. If so, then
1445 * GFP_NOWAIT is used instead to get an extra object for
1446 * split purpose. That is rare and most time does not
1447 * occur.
1448 *
1449 * What happens if an allocation gets failed. Basically,
1450 * an "overflow" path is triggered to purge lazily freed
1451 * areas to free some memory, then, the "retry" path is
1452 * triggered to repeat one more time. See more details
1453 * in alloc_vmap_area() function.
1454 */
1455 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
1456 if (!lva)
1457 return -1;
1458 }
1459
1460 /*
1461 * Build the remainder.
1462 */
1463 lva->va_start = va->va_start;
1464 lva->va_end = nva_start_addr;
1465
1466 /*
1467 * Shrink this VA to remaining size.
1468 */
1469 va->va_start = nva_start_addr + size;
1470 } else {
1471 return -1;
1472 }
1473
1474 if (type != FL_FIT_TYPE) {
1475 augment_tree_propagate_from(va);
1476
1477 if (lva) /* type == NE_FIT_TYPE */
1478 insert_vmap_area_augment(lva, &va->rb_node, root, head);
1479 }
1480
1481 return 0;
1482}
1483
1484/*
1485 * Returns a start address of the newly allocated area, if success.
1486 * Otherwise a vend is returned that indicates failure.
1487 */
1488static __always_inline unsigned long
1489__alloc_vmap_area(struct rb_root *root, struct list_head *head,
1490 unsigned long size, unsigned long align,
1491 unsigned long vstart, unsigned long vend)
1492{
1493 bool adjust_search_size = true;
1494 unsigned long nva_start_addr;
1495 struct vmap_area *va;
1496 int ret;
1497
1498 /*
1499 * Do not adjust when:
1500 * a) align <= PAGE_SIZE, because it does not make any sense.
1501 * All blocks(their start addresses) are at least PAGE_SIZE
1502 * aligned anyway;
1503 * b) a short range where a requested size corresponds to exactly
1504 * specified [vstart:vend] interval and an alignment > PAGE_SIZE.
1505 * With adjusted search length an allocation would not succeed.
1506 */
1507 if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size))
1508 adjust_search_size = false;
1509
1510 va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size);
1511 if (unlikely(!va))
1512 return vend;
1513
1514 if (va->va_start > vstart)
1515 nva_start_addr = ALIGN(va->va_start, align);
1516 else
1517 nva_start_addr = ALIGN(vstart, align);
1518
1519 /* Check the "vend" restriction. */
1520 if (nva_start_addr + size > vend)
1521 return vend;
1522
1523 /* Update the free vmap_area. */
1524 ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
1525 if (WARN_ON_ONCE(ret))
1526 return vend;
1527
1528#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1529 find_vmap_lowest_match_check(root, head, size, align);
1530#endif
1531
1532 return nva_start_addr;
1533}
1534
1535/*
1536 * Free a region of KVA allocated by alloc_vmap_area
1537 */
1538static void free_vmap_area(struct vmap_area *va)
1539{
1540 /*
1541 * Remove from the busy tree/list.
1542 */
1543 spin_lock(&vmap_area_lock);
1544 unlink_va(va, &vmap_area_root);
1545 spin_unlock(&vmap_area_lock);
1546
1547 /*
1548 * Insert/Merge it back to the free tree/list.
1549 */
1550 spin_lock(&free_vmap_area_lock);
1551 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list);
1552 spin_unlock(&free_vmap_area_lock);
1553}
1554
1555static inline void
1556preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
1557{
1558 struct vmap_area *va = NULL;
1559
1560 /*
1561 * Preload this CPU with one extra vmap_area object. It is used
1562 * when fit type of free area is NE_FIT_TYPE. It guarantees that
1563 * a CPU that does an allocation is preloaded.
1564 *
1565 * We do it in non-atomic context, thus it allows us to use more
1566 * permissive allocation masks to be more stable under low memory
1567 * condition and high memory pressure.
1568 */
1569 if (!this_cpu_read(ne_fit_preload_node))
1570 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1571
1572 spin_lock(lock);
1573
1574 if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va))
1575 kmem_cache_free(vmap_area_cachep, va);
1576}
1577
1578/*
1579 * Allocate a region of KVA of the specified size and alignment, within the
1580 * vstart and vend.
1581 */
1582static struct vmap_area *alloc_vmap_area(unsigned long size,
1583 unsigned long align,
1584 unsigned long vstart, unsigned long vend,
1585 int node, gfp_t gfp_mask,
1586 unsigned long va_flags)
1587{
1588 struct vmap_area *va;
1589 unsigned long freed;
1590 unsigned long addr;
1591 int purged = 0;
1592 int ret;
1593
1594 if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
1595 return ERR_PTR(-EINVAL);
1596
1597 if (unlikely(!vmap_initialized))
1598 return ERR_PTR(-EBUSY);
1599
1600 might_sleep();
1601 gfp_mask = gfp_mask & GFP_RECLAIM_MASK;
1602
1603 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1604 if (unlikely(!va))
1605 return ERR_PTR(-ENOMEM);
1606
1607 /*
1608 * Only scan the relevant parts containing pointers to other objects
1609 * to avoid false negatives.
1610 */
1611 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask);
1612
1613retry:
1614 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node);
1615 addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list,
1616 size, align, vstart, vend);
1617 spin_unlock(&free_vmap_area_lock);
1618
1619 trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend);
1620
1621 /*
1622 * If an allocation fails, the "vend" address is
1623 * returned. Therefore trigger the overflow path.
1624 */
1625 if (unlikely(addr == vend))
1626 goto overflow;
1627
1628 va->va_start = addr;
1629 va->va_end = addr + size;
1630 va->vm = NULL;
1631 va->flags = va_flags;
1632
1633 spin_lock(&vmap_area_lock);
1634 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
1635 spin_unlock(&vmap_area_lock);
1636
1637 BUG_ON(!IS_ALIGNED(va->va_start, align));
1638 BUG_ON(va->va_start < vstart);
1639 BUG_ON(va->va_end > vend);
1640
1641 ret = kasan_populate_vmalloc(addr, size);
1642 if (ret) {
1643 free_vmap_area(va);
1644 return ERR_PTR(ret);
1645 }
1646
1647 return va;
1648
1649overflow:
1650 if (!purged) {
1651 reclaim_and_purge_vmap_areas();
1652 purged = 1;
1653 goto retry;
1654 }
1655
1656 freed = 0;
1657 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
1658
1659 if (freed > 0) {
1660 purged = 0;
1661 goto retry;
1662 }
1663
1664 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
1665 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
1666 size);
1667
1668 kmem_cache_free(vmap_area_cachep, va);
1669 return ERR_PTR(-EBUSY);
1670}
1671
1672int register_vmap_purge_notifier(struct notifier_block *nb)
1673{
1674 return blocking_notifier_chain_register(&vmap_notify_list, nb);
1675}
1676EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
1677
1678int unregister_vmap_purge_notifier(struct notifier_block *nb)
1679{
1680 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
1681}
1682EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
1683
1684/*
1685 * lazy_max_pages is the maximum amount of virtual address space we gather up
1686 * before attempting to purge with a TLB flush.
1687 *
1688 * There is a tradeoff here: a larger number will cover more kernel page tables
1689 * and take slightly longer to purge, but it will linearly reduce the number of
1690 * global TLB flushes that must be performed. It would seem natural to scale
1691 * this number up linearly with the number of CPUs (because vmapping activity
1692 * could also scale linearly with the number of CPUs), however it is likely
1693 * that in practice, workloads might be constrained in other ways that mean
1694 * vmap activity will not scale linearly with CPUs. Also, I want to be
1695 * conservative and not introduce a big latency on huge systems, so go with
1696 * a less aggressive log scale. It will still be an improvement over the old
1697 * code, and it will be simple to change the scale factor if we find that it
1698 * becomes a problem on bigger systems.
1699 */
1700static unsigned long lazy_max_pages(void)
1701{
1702 unsigned int log;
1703
1704 log = fls(num_online_cpus());
1705
1706 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
1707}
1708
1709static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
1710
1711/*
1712 * Serialize vmap purging. There is no actual critical section protected
1713 * by this lock, but we want to avoid concurrent calls for performance
1714 * reasons and to make the pcpu_get_vm_areas more deterministic.
1715 */
1716static DEFINE_MUTEX(vmap_purge_lock);
1717
1718/* for per-CPU blocks */
1719static void purge_fragmented_blocks_allcpus(void);
1720
1721/*
1722 * Purges all lazily-freed vmap areas.
1723 */
1724static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
1725{
1726 unsigned long resched_threshold;
1727 unsigned int num_purged_areas = 0;
1728 struct list_head local_purge_list;
1729 struct vmap_area *va, *n_va;
1730
1731 lockdep_assert_held(&vmap_purge_lock);
1732
1733 spin_lock(&purge_vmap_area_lock);
1734 purge_vmap_area_root = RB_ROOT;
1735 list_replace_init(&purge_vmap_area_list, &local_purge_list);
1736 spin_unlock(&purge_vmap_area_lock);
1737
1738 if (unlikely(list_empty(&local_purge_list)))
1739 goto out;
1740
1741 start = min(start,
1742 list_first_entry(&local_purge_list,
1743 struct vmap_area, list)->va_start);
1744
1745 end = max(end,
1746 list_last_entry(&local_purge_list,
1747 struct vmap_area, list)->va_end);
1748
1749 flush_tlb_kernel_range(start, end);
1750 resched_threshold = lazy_max_pages() << 1;
1751
1752 spin_lock(&free_vmap_area_lock);
1753 list_for_each_entry_safe(va, n_va, &local_purge_list, list) {
1754 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
1755 unsigned long orig_start = va->va_start;
1756 unsigned long orig_end = va->va_end;
1757
1758 /*
1759 * Finally insert or merge lazily-freed area. It is
1760 * detached and there is no need to "unlink" it from
1761 * anything.
1762 */
1763 va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root,
1764 &free_vmap_area_list);
1765
1766 if (!va)
1767 continue;
1768
1769 if (is_vmalloc_or_module_addr((void *)orig_start))
1770 kasan_release_vmalloc(orig_start, orig_end,
1771 va->va_start, va->va_end);
1772
1773 atomic_long_sub(nr, &vmap_lazy_nr);
1774 num_purged_areas++;
1775
1776 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
1777 cond_resched_lock(&free_vmap_area_lock);
1778 }
1779 spin_unlock(&free_vmap_area_lock);
1780
1781out:
1782 trace_purge_vmap_area_lazy(start, end, num_purged_areas);
1783 return num_purged_areas > 0;
1784}
1785
1786/*
1787 * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list.
1788 */
1789static void reclaim_and_purge_vmap_areas(void)
1790
1791{
1792 mutex_lock(&vmap_purge_lock);
1793 purge_fragmented_blocks_allcpus();
1794 __purge_vmap_area_lazy(ULONG_MAX, 0);
1795 mutex_unlock(&vmap_purge_lock);
1796}
1797
1798static void drain_vmap_area_work(struct work_struct *work)
1799{
1800 unsigned long nr_lazy;
1801
1802 do {
1803 mutex_lock(&vmap_purge_lock);
1804 __purge_vmap_area_lazy(ULONG_MAX, 0);
1805 mutex_unlock(&vmap_purge_lock);
1806
1807 /* Recheck if further work is required. */
1808 nr_lazy = atomic_long_read(&vmap_lazy_nr);
1809 } while (nr_lazy > lazy_max_pages());
1810}
1811
1812/*
1813 * Free a vmap area, caller ensuring that the area has been unmapped,
1814 * unlinked and flush_cache_vunmap had been called for the correct
1815 * range previously.
1816 */
1817static void free_vmap_area_noflush(struct vmap_area *va)
1818{
1819 unsigned long nr_lazy_max = lazy_max_pages();
1820 unsigned long va_start = va->va_start;
1821 unsigned long nr_lazy;
1822
1823 if (WARN_ON_ONCE(!list_empty(&va->list)))
1824 return;
1825
1826 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
1827 PAGE_SHIFT, &vmap_lazy_nr);
1828
1829 /*
1830 * Merge or place it to the purge tree/list.
1831 */
1832 spin_lock(&purge_vmap_area_lock);
1833 merge_or_add_vmap_area(va,
1834 &purge_vmap_area_root, &purge_vmap_area_list);
1835 spin_unlock(&purge_vmap_area_lock);
1836
1837 trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max);
1838
1839 /* After this point, we may free va at any time */
1840 if (unlikely(nr_lazy > nr_lazy_max))
1841 schedule_work(&drain_vmap_work);
1842}
1843
1844/*
1845 * Free and unmap a vmap area
1846 */
1847static void free_unmap_vmap_area(struct vmap_area *va)
1848{
1849 flush_cache_vunmap(va->va_start, va->va_end);
1850 vunmap_range_noflush(va->va_start, va->va_end);
1851 if (debug_pagealloc_enabled_static())
1852 flush_tlb_kernel_range(va->va_start, va->va_end);
1853
1854 free_vmap_area_noflush(va);
1855}
1856
1857struct vmap_area *find_vmap_area(unsigned long addr)
1858{
1859 struct vmap_area *va;
1860
1861 spin_lock(&vmap_area_lock);
1862 va = __find_vmap_area(addr, &vmap_area_root);
1863 spin_unlock(&vmap_area_lock);
1864
1865 return va;
1866}
1867
1868static struct vmap_area *find_unlink_vmap_area(unsigned long addr)
1869{
1870 struct vmap_area *va;
1871
1872 spin_lock(&vmap_area_lock);
1873 va = __find_vmap_area(addr, &vmap_area_root);
1874 if (va)
1875 unlink_va(va, &vmap_area_root);
1876 spin_unlock(&vmap_area_lock);
1877
1878 return va;
1879}
1880
1881/*** Per cpu kva allocator ***/
1882
1883/*
1884 * vmap space is limited especially on 32 bit architectures. Ensure there is
1885 * room for at least 16 percpu vmap blocks per CPU.
1886 */
1887/*
1888 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
1889 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
1890 * instead (we just need a rough idea)
1891 */
1892#if BITS_PER_LONG == 32
1893#define VMALLOC_SPACE (128UL*1024*1024)
1894#else
1895#define VMALLOC_SPACE (128UL*1024*1024*1024)
1896#endif
1897
1898#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
1899#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
1900#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
1901#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
1902#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
1903#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
1904#define VMAP_BBMAP_BITS \
1905 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
1906 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
1907 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
1908
1909#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
1910
1911/*
1912 * Purge threshold to prevent overeager purging of fragmented blocks for
1913 * regular operations: Purge if vb->free is less than 1/4 of the capacity.
1914 */
1915#define VMAP_PURGE_THRESHOLD (VMAP_BBMAP_BITS / 4)
1916
1917#define VMAP_RAM 0x1 /* indicates vm_map_ram area*/
1918#define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/
1919#define VMAP_FLAGS_MASK 0x3
1920
1921struct vmap_block_queue {
1922 spinlock_t lock;
1923 struct list_head free;
1924
1925 /*
1926 * An xarray requires an extra memory dynamically to
1927 * be allocated. If it is an issue, we can use rb-tree
1928 * instead.
1929 */
1930 struct xarray vmap_blocks;
1931};
1932
1933struct vmap_block {
1934 spinlock_t lock;
1935 struct vmap_area *va;
1936 unsigned long free, dirty;
1937 DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS);
1938 unsigned long dirty_min, dirty_max; /*< dirty range */
1939 struct list_head free_list;
1940 struct rcu_head rcu_head;
1941 struct list_head purge;
1942};
1943
1944/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
1945static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
1946
1947/*
1948 * In order to fast access to any "vmap_block" associated with a
1949 * specific address, we use a hash.
1950 *
1951 * A per-cpu vmap_block_queue is used in both ways, to serialize
1952 * an access to free block chains among CPUs(alloc path) and it
1953 * also acts as a vmap_block hash(alloc/free paths). It means we
1954 * overload it, since we already have the per-cpu array which is
1955 * used as a hash table. When used as a hash a 'cpu' passed to
1956 * per_cpu() is not actually a CPU but rather a hash index.
1957 *
1958 * A hash function is addr_to_vb_xa() which hashes any address
1959 * to a specific index(in a hash) it belongs to. This then uses a
1960 * per_cpu() macro to access an array with generated index.
1961 *
1962 * An example:
1963 *
1964 * CPU_1 CPU_2 CPU_0
1965 * | | |
1966 * V V V
1967 * 0 10 20 30 40 50 60
1968 * |------|------|------|------|------|------|...<vmap address space>
1969 * CPU0 CPU1 CPU2 CPU0 CPU1 CPU2
1970 *
1971 * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus
1972 * it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock;
1973 *
1974 * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus
1975 * it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock;
1976 *
1977 * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus
1978 * it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock.
1979 *
1980 * This technique almost always avoids lock contention on insert/remove,
1981 * however xarray spinlocks protect against any contention that remains.
1982 */
1983static struct xarray *
1984addr_to_vb_xa(unsigned long addr)
1985{
1986 int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus();
1987
1988 return &per_cpu(vmap_block_queue, index).vmap_blocks;
1989}
1990
1991/*
1992 * We should probably have a fallback mechanism to allocate virtual memory
1993 * out of partially filled vmap blocks. However vmap block sizing should be
1994 * fairly reasonable according to the vmalloc size, so it shouldn't be a
1995 * big problem.
1996 */
1997
1998static unsigned long addr_to_vb_idx(unsigned long addr)
1999{
2000 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
2001 addr /= VMAP_BLOCK_SIZE;
2002 return addr;
2003}
2004
2005static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
2006{
2007 unsigned long addr;
2008
2009 addr = va_start + (pages_off << PAGE_SHIFT);
2010 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
2011 return (void *)addr;
2012}
2013
2014/**
2015 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
2016 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
2017 * @order: how many 2^order pages should be occupied in newly allocated block
2018 * @gfp_mask: flags for the page level allocator
2019 *
2020 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
2021 */
2022static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
2023{
2024 struct vmap_block_queue *vbq;
2025 struct vmap_block *vb;
2026 struct vmap_area *va;
2027 struct xarray *xa;
2028 unsigned long vb_idx;
2029 int node, err;
2030 void *vaddr;
2031
2032 node = numa_node_id();
2033
2034 vb = kmalloc_node(sizeof(struct vmap_block),
2035 gfp_mask & GFP_RECLAIM_MASK, node);
2036 if (unlikely(!vb))
2037 return ERR_PTR(-ENOMEM);
2038
2039 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
2040 VMALLOC_START, VMALLOC_END,
2041 node, gfp_mask,
2042 VMAP_RAM|VMAP_BLOCK);
2043 if (IS_ERR(va)) {
2044 kfree(vb);
2045 return ERR_CAST(va);
2046 }
2047
2048 vaddr = vmap_block_vaddr(va->va_start, 0);
2049 spin_lock_init(&vb->lock);
2050 vb->va = va;
2051 /* At least something should be left free */
2052 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
2053 bitmap_zero(vb->used_map, VMAP_BBMAP_BITS);
2054 vb->free = VMAP_BBMAP_BITS - (1UL << order);
2055 vb->dirty = 0;
2056 vb->dirty_min = VMAP_BBMAP_BITS;
2057 vb->dirty_max = 0;
2058 bitmap_set(vb->used_map, 0, (1UL << order));
2059 INIT_LIST_HEAD(&vb->free_list);
2060
2061 xa = addr_to_vb_xa(va->va_start);
2062 vb_idx = addr_to_vb_idx(va->va_start);
2063 err = xa_insert(xa, vb_idx, vb, gfp_mask);
2064 if (err) {
2065 kfree(vb);
2066 free_vmap_area(va);
2067 return ERR_PTR(err);
2068 }
2069
2070 vbq = raw_cpu_ptr(&vmap_block_queue);
2071 spin_lock(&vbq->lock);
2072 list_add_tail_rcu(&vb->free_list, &vbq->free);
2073 spin_unlock(&vbq->lock);
2074
2075 return vaddr;
2076}
2077
2078static void free_vmap_block(struct vmap_block *vb)
2079{
2080 struct vmap_block *tmp;
2081 struct xarray *xa;
2082
2083 xa = addr_to_vb_xa(vb->va->va_start);
2084 tmp = xa_erase(xa, addr_to_vb_idx(vb->va->va_start));
2085 BUG_ON(tmp != vb);
2086
2087 spin_lock(&vmap_area_lock);
2088 unlink_va(vb->va, &vmap_area_root);
2089 spin_unlock(&vmap_area_lock);
2090
2091 free_vmap_area_noflush(vb->va);
2092 kfree_rcu(vb, rcu_head);
2093}
2094
2095static bool purge_fragmented_block(struct vmap_block *vb,
2096 struct vmap_block_queue *vbq, struct list_head *purge_list,
2097 bool force_purge)
2098{
2099 if (vb->free + vb->dirty != VMAP_BBMAP_BITS ||
2100 vb->dirty == VMAP_BBMAP_BITS)
2101 return false;
2102
2103 /* Don't overeagerly purge usable blocks unless requested */
2104 if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD))
2105 return false;
2106
2107 /* prevent further allocs after releasing lock */
2108 WRITE_ONCE(vb->free, 0);
2109 /* prevent purging it again */
2110 WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS);
2111 vb->dirty_min = 0;
2112 vb->dirty_max = VMAP_BBMAP_BITS;
2113 spin_lock(&vbq->lock);
2114 list_del_rcu(&vb->free_list);
2115 spin_unlock(&vbq->lock);
2116 list_add_tail(&vb->purge, purge_list);
2117 return true;
2118}
2119
2120static void free_purged_blocks(struct list_head *purge_list)
2121{
2122 struct vmap_block *vb, *n_vb;
2123
2124 list_for_each_entry_safe(vb, n_vb, purge_list, purge) {
2125 list_del(&vb->purge);
2126 free_vmap_block(vb);
2127 }
2128}
2129
2130static void purge_fragmented_blocks(int cpu)
2131{
2132 LIST_HEAD(purge);
2133 struct vmap_block *vb;
2134 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2135
2136 rcu_read_lock();
2137 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2138 unsigned long free = READ_ONCE(vb->free);
2139 unsigned long dirty = READ_ONCE(vb->dirty);
2140
2141 if (free + dirty != VMAP_BBMAP_BITS ||
2142 dirty == VMAP_BBMAP_BITS)
2143 continue;
2144
2145 spin_lock(&vb->lock);
2146 purge_fragmented_block(vb, vbq, &purge, true);
2147 spin_unlock(&vb->lock);
2148 }
2149 rcu_read_unlock();
2150 free_purged_blocks(&purge);
2151}
2152
2153static void purge_fragmented_blocks_allcpus(void)
2154{
2155 int cpu;
2156
2157 for_each_possible_cpu(cpu)
2158 purge_fragmented_blocks(cpu);
2159}
2160
2161static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
2162{
2163 struct vmap_block_queue *vbq;
2164 struct vmap_block *vb;
2165 void *vaddr = NULL;
2166 unsigned int order;
2167
2168 BUG_ON(offset_in_page(size));
2169 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2170 if (WARN_ON(size == 0)) {
2171 /*
2172 * Allocating 0 bytes isn't what caller wants since
2173 * get_order(0) returns funny result. Just warn and terminate
2174 * early.
2175 */
2176 return NULL;
2177 }
2178 order = get_order(size);
2179
2180 rcu_read_lock();
2181 vbq = raw_cpu_ptr(&vmap_block_queue);
2182 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2183 unsigned long pages_off;
2184
2185 if (READ_ONCE(vb->free) < (1UL << order))
2186 continue;
2187
2188 spin_lock(&vb->lock);
2189 if (vb->free < (1UL << order)) {
2190 spin_unlock(&vb->lock);
2191 continue;
2192 }
2193
2194 pages_off = VMAP_BBMAP_BITS - vb->free;
2195 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
2196 WRITE_ONCE(vb->free, vb->free - (1UL << order));
2197 bitmap_set(vb->used_map, pages_off, (1UL << order));
2198 if (vb->free == 0) {
2199 spin_lock(&vbq->lock);
2200 list_del_rcu(&vb->free_list);
2201 spin_unlock(&vbq->lock);
2202 }
2203
2204 spin_unlock(&vb->lock);
2205 break;
2206 }
2207
2208 rcu_read_unlock();
2209
2210 /* Allocate new block if nothing was found */
2211 if (!vaddr)
2212 vaddr = new_vmap_block(order, gfp_mask);
2213
2214 return vaddr;
2215}
2216
2217static void vb_free(unsigned long addr, unsigned long size)
2218{
2219 unsigned long offset;
2220 unsigned int order;
2221 struct vmap_block *vb;
2222 struct xarray *xa;
2223
2224 BUG_ON(offset_in_page(size));
2225 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2226
2227 flush_cache_vunmap(addr, addr + size);
2228
2229 order = get_order(size);
2230 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
2231
2232 xa = addr_to_vb_xa(addr);
2233 vb = xa_load(xa, addr_to_vb_idx(addr));
2234
2235 spin_lock(&vb->lock);
2236 bitmap_clear(vb->used_map, offset, (1UL << order));
2237 spin_unlock(&vb->lock);
2238
2239 vunmap_range_noflush(addr, addr + size);
2240
2241 if (debug_pagealloc_enabled_static())
2242 flush_tlb_kernel_range(addr, addr + size);
2243
2244 spin_lock(&vb->lock);
2245
2246 /* Expand the not yet TLB flushed dirty range */
2247 vb->dirty_min = min(vb->dirty_min, offset);
2248 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
2249
2250 WRITE_ONCE(vb->dirty, vb->dirty + (1UL << order));
2251 if (vb->dirty == VMAP_BBMAP_BITS) {
2252 BUG_ON(vb->free);
2253 spin_unlock(&vb->lock);
2254 free_vmap_block(vb);
2255 } else
2256 spin_unlock(&vb->lock);
2257}
2258
2259static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
2260{
2261 LIST_HEAD(purge_list);
2262 int cpu;
2263
2264 if (unlikely(!vmap_initialized))
2265 return;
2266
2267 mutex_lock(&vmap_purge_lock);
2268
2269 for_each_possible_cpu(cpu) {
2270 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2271 struct vmap_block *vb;
2272 unsigned long idx;
2273
2274 rcu_read_lock();
2275 xa_for_each(&vbq->vmap_blocks, idx, vb) {
2276 spin_lock(&vb->lock);
2277
2278 /*
2279 * Try to purge a fragmented block first. If it's
2280 * not purgeable, check whether there is dirty
2281 * space to be flushed.
2282 */
2283 if (!purge_fragmented_block(vb, vbq, &purge_list, false) &&
2284 vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) {
2285 unsigned long va_start = vb->va->va_start;
2286 unsigned long s, e;
2287
2288 s = va_start + (vb->dirty_min << PAGE_SHIFT);
2289 e = va_start + (vb->dirty_max << PAGE_SHIFT);
2290
2291 start = min(s, start);
2292 end = max(e, end);
2293
2294 /* Prevent that this is flushed again */
2295 vb->dirty_min = VMAP_BBMAP_BITS;
2296 vb->dirty_max = 0;
2297
2298 flush = 1;
2299 }
2300 spin_unlock(&vb->lock);
2301 }
2302 rcu_read_unlock();
2303 }
2304 free_purged_blocks(&purge_list);
2305
2306 if (!__purge_vmap_area_lazy(start, end) && flush)
2307 flush_tlb_kernel_range(start, end);
2308 mutex_unlock(&vmap_purge_lock);
2309}
2310
2311/**
2312 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
2313 *
2314 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
2315 * to amortize TLB flushing overheads. What this means is that any page you
2316 * have now, may, in a former life, have been mapped into kernel virtual
2317 * address by the vmap layer and so there might be some CPUs with TLB entries
2318 * still referencing that page (additional to the regular 1:1 kernel mapping).
2319 *
2320 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
2321 * be sure that none of the pages we have control over will have any aliases
2322 * from the vmap layer.
2323 */
2324void vm_unmap_aliases(void)
2325{
2326 unsigned long start = ULONG_MAX, end = 0;
2327 int flush = 0;
2328
2329 _vm_unmap_aliases(start, end, flush);
2330}
2331EXPORT_SYMBOL_GPL(vm_unmap_aliases);
2332
2333/**
2334 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
2335 * @mem: the pointer returned by vm_map_ram
2336 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
2337 */
2338void vm_unmap_ram(const void *mem, unsigned int count)
2339{
2340 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2341 unsigned long addr = (unsigned long)kasan_reset_tag(mem);
2342 struct vmap_area *va;
2343
2344 might_sleep();
2345 BUG_ON(!addr);
2346 BUG_ON(addr < VMALLOC_START);
2347 BUG_ON(addr > VMALLOC_END);
2348 BUG_ON(!PAGE_ALIGNED(addr));
2349
2350 kasan_poison_vmalloc(mem, size);
2351
2352 if (likely(count <= VMAP_MAX_ALLOC)) {
2353 debug_check_no_locks_freed(mem, size);
2354 vb_free(addr, size);
2355 return;
2356 }
2357
2358 va = find_unlink_vmap_area(addr);
2359 if (WARN_ON_ONCE(!va))
2360 return;
2361
2362 debug_check_no_locks_freed((void *)va->va_start,
2363 (va->va_end - va->va_start));
2364 free_unmap_vmap_area(va);
2365}
2366EXPORT_SYMBOL(vm_unmap_ram);
2367
2368/**
2369 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
2370 * @pages: an array of pointers to the pages to be mapped
2371 * @count: number of pages
2372 * @node: prefer to allocate data structures on this node
2373 *
2374 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
2375 * faster than vmap so it's good. But if you mix long-life and short-life
2376 * objects with vm_map_ram(), it could consume lots of address space through
2377 * fragmentation (especially on a 32bit machine). You could see failures in
2378 * the end. Please use this function for short-lived objects.
2379 *
2380 * Returns: a pointer to the address that has been mapped, or %NULL on failure
2381 */
2382void *vm_map_ram(struct page **pages, unsigned int count, int node)
2383{
2384 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2385 unsigned long addr;
2386 void *mem;
2387
2388 if (likely(count <= VMAP_MAX_ALLOC)) {
2389 mem = vb_alloc(size, GFP_KERNEL);
2390 if (IS_ERR(mem))
2391 return NULL;
2392 addr = (unsigned long)mem;
2393 } else {
2394 struct vmap_area *va;
2395 va = alloc_vmap_area(size, PAGE_SIZE,
2396 VMALLOC_START, VMALLOC_END,
2397 node, GFP_KERNEL, VMAP_RAM);
2398 if (IS_ERR(va))
2399 return NULL;
2400
2401 addr = va->va_start;
2402 mem = (void *)addr;
2403 }
2404
2405 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
2406 pages, PAGE_SHIFT) < 0) {
2407 vm_unmap_ram(mem, count);
2408 return NULL;
2409 }
2410
2411 /*
2412 * Mark the pages as accessible, now that they are mapped.
2413 * With hardware tag-based KASAN, marking is skipped for
2414 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
2415 */
2416 mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL);
2417
2418 return mem;
2419}
2420EXPORT_SYMBOL(vm_map_ram);
2421
2422static struct vm_struct *vmlist __initdata;
2423
2424static inline unsigned int vm_area_page_order(struct vm_struct *vm)
2425{
2426#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2427 return vm->page_order;
2428#else
2429 return 0;
2430#endif
2431}
2432
2433static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
2434{
2435#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2436 vm->page_order = order;
2437#else
2438 BUG_ON(order != 0);
2439#endif
2440}
2441
2442/**
2443 * vm_area_add_early - add vmap area early during boot
2444 * @vm: vm_struct to add
2445 *
2446 * This function is used to add fixed kernel vm area to vmlist before
2447 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
2448 * should contain proper values and the other fields should be zero.
2449 *
2450 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2451 */
2452void __init vm_area_add_early(struct vm_struct *vm)
2453{
2454 struct vm_struct *tmp, **p;
2455
2456 BUG_ON(vmap_initialized);
2457 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
2458 if (tmp->addr >= vm->addr) {
2459 BUG_ON(tmp->addr < vm->addr + vm->size);
2460 break;
2461 } else
2462 BUG_ON(tmp->addr + tmp->size > vm->addr);
2463 }
2464 vm->next = *p;
2465 *p = vm;
2466}
2467
2468/**
2469 * vm_area_register_early - register vmap area early during boot
2470 * @vm: vm_struct to register
2471 * @align: requested alignment
2472 *
2473 * This function is used to register kernel vm area before
2474 * vmalloc_init() is called. @vm->size and @vm->flags should contain
2475 * proper values on entry and other fields should be zero. On return,
2476 * vm->addr contains the allocated address.
2477 *
2478 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2479 */
2480void __init vm_area_register_early(struct vm_struct *vm, size_t align)
2481{
2482 unsigned long addr = ALIGN(VMALLOC_START, align);
2483 struct vm_struct *cur, **p;
2484
2485 BUG_ON(vmap_initialized);
2486
2487 for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) {
2488 if ((unsigned long)cur->addr - addr >= vm->size)
2489 break;
2490 addr = ALIGN((unsigned long)cur->addr + cur->size, align);
2491 }
2492
2493 BUG_ON(addr > VMALLOC_END - vm->size);
2494 vm->addr = (void *)addr;
2495 vm->next = *p;
2496 *p = vm;
2497 kasan_populate_early_vm_area_shadow(vm->addr, vm->size);
2498}
2499
2500static void vmap_init_free_space(void)
2501{
2502 unsigned long vmap_start = 1;
2503 const unsigned long vmap_end = ULONG_MAX;
2504 struct vmap_area *busy, *free;
2505
2506 /*
2507 * B F B B B F
2508 * -|-----|.....|-----|-----|-----|.....|-
2509 * | The KVA space |
2510 * |<--------------------------------->|
2511 */
2512 list_for_each_entry(busy, &vmap_area_list, list) {
2513 if (busy->va_start - vmap_start > 0) {
2514 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2515 if (!WARN_ON_ONCE(!free)) {
2516 free->va_start = vmap_start;
2517 free->va_end = busy->va_start;
2518
2519 insert_vmap_area_augment(free, NULL,
2520 &free_vmap_area_root,
2521 &free_vmap_area_list);
2522 }
2523 }
2524
2525 vmap_start = busy->va_end;
2526 }
2527
2528 if (vmap_end - vmap_start > 0) {
2529 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2530 if (!WARN_ON_ONCE(!free)) {
2531 free->va_start = vmap_start;
2532 free->va_end = vmap_end;
2533
2534 insert_vmap_area_augment(free, NULL,
2535 &free_vmap_area_root,
2536 &free_vmap_area_list);
2537 }
2538 }
2539}
2540
2541static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
2542 struct vmap_area *va, unsigned long flags, const void *caller)
2543{
2544 vm->flags = flags;
2545 vm->addr = (void *)va->va_start;
2546 vm->size = va->va_end - va->va_start;
2547 vm->caller = caller;
2548 va->vm = vm;
2549}
2550
2551static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
2552 unsigned long flags, const void *caller)
2553{
2554 spin_lock(&vmap_area_lock);
2555 setup_vmalloc_vm_locked(vm, va, flags, caller);
2556 spin_unlock(&vmap_area_lock);
2557}
2558
2559static void clear_vm_uninitialized_flag(struct vm_struct *vm)
2560{
2561 /*
2562 * Before removing VM_UNINITIALIZED,
2563 * we should make sure that vm has proper values.
2564 * Pair with smp_rmb() in show_numa_info().
2565 */
2566 smp_wmb();
2567 vm->flags &= ~VM_UNINITIALIZED;
2568}
2569
2570static struct vm_struct *__get_vm_area_node(unsigned long size,
2571 unsigned long align, unsigned long shift, unsigned long flags,
2572 unsigned long start, unsigned long end, int node,
2573 gfp_t gfp_mask, const void *caller)
2574{
2575 struct vmap_area *va;
2576 struct vm_struct *area;
2577 unsigned long requested_size = size;
2578
2579 BUG_ON(in_interrupt());
2580 size = ALIGN(size, 1ul << shift);
2581 if (unlikely(!size))
2582 return NULL;
2583
2584 if (flags & VM_IOREMAP)
2585 align = 1ul << clamp_t(int, get_count_order_long(size),
2586 PAGE_SHIFT, IOREMAP_MAX_ORDER);
2587
2588 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
2589 if (unlikely(!area))
2590 return NULL;
2591
2592 if (!(flags & VM_NO_GUARD))
2593 size += PAGE_SIZE;
2594
2595 va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0);
2596 if (IS_ERR(va)) {
2597 kfree(area);
2598 return NULL;
2599 }
2600
2601 setup_vmalloc_vm(area, va, flags, caller);
2602
2603 /*
2604 * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a
2605 * best-effort approach, as they can be mapped outside of vmalloc code.
2606 * For VM_ALLOC mappings, the pages are marked as accessible after
2607 * getting mapped in __vmalloc_node_range().
2608 * With hardware tag-based KASAN, marking is skipped for
2609 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
2610 */
2611 if (!(flags & VM_ALLOC))
2612 area->addr = kasan_unpoison_vmalloc(area->addr, requested_size,
2613 KASAN_VMALLOC_PROT_NORMAL);
2614
2615 return area;
2616}
2617
2618struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
2619 unsigned long start, unsigned long end,
2620 const void *caller)
2621{
2622 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end,
2623 NUMA_NO_NODE, GFP_KERNEL, caller);
2624}
2625
2626/**
2627 * get_vm_area - reserve a contiguous kernel virtual area
2628 * @size: size of the area
2629 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
2630 *
2631 * Search an area of @size in the kernel virtual mapping area,
2632 * and reserved it for out purposes. Returns the area descriptor
2633 * on success or %NULL on failure.
2634 *
2635 * Return: the area descriptor on success or %NULL on failure.
2636 */
2637struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
2638{
2639 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2640 VMALLOC_START, VMALLOC_END,
2641 NUMA_NO_NODE, GFP_KERNEL,
2642 __builtin_return_address(0));
2643}
2644
2645struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
2646 const void *caller)
2647{
2648 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2649 VMALLOC_START, VMALLOC_END,
2650 NUMA_NO_NODE, GFP_KERNEL, caller);
2651}
2652
2653/**
2654 * find_vm_area - find a continuous kernel virtual area
2655 * @addr: base address
2656 *
2657 * Search for the kernel VM area starting at @addr, and return it.
2658 * It is up to the caller to do all required locking to keep the returned
2659 * pointer valid.
2660 *
2661 * Return: the area descriptor on success or %NULL on failure.
2662 */
2663struct vm_struct *find_vm_area(const void *addr)
2664{
2665 struct vmap_area *va;
2666
2667 va = find_vmap_area((unsigned long)addr);
2668 if (!va)
2669 return NULL;
2670
2671 return va->vm;
2672}
2673
2674/**
2675 * remove_vm_area - find and remove a continuous kernel virtual area
2676 * @addr: base address
2677 *
2678 * Search for the kernel VM area starting at @addr, and remove it.
2679 * This function returns the found VM area, but using it is NOT safe
2680 * on SMP machines, except for its size or flags.
2681 *
2682 * Return: the area descriptor on success or %NULL on failure.
2683 */
2684struct vm_struct *remove_vm_area(const void *addr)
2685{
2686 struct vmap_area *va;
2687 struct vm_struct *vm;
2688
2689 might_sleep();
2690
2691 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
2692 addr))
2693 return NULL;
2694
2695 va = find_unlink_vmap_area((unsigned long)addr);
2696 if (!va || !va->vm)
2697 return NULL;
2698 vm = va->vm;
2699
2700 debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm));
2701 debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm));
2702 kasan_free_module_shadow(vm);
2703 kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm));
2704
2705 free_unmap_vmap_area(va);
2706 return vm;
2707}
2708
2709static inline void set_area_direct_map(const struct vm_struct *area,
2710 int (*set_direct_map)(struct page *page))
2711{
2712 int i;
2713
2714 /* HUGE_VMALLOC passes small pages to set_direct_map */
2715 for (i = 0; i < area->nr_pages; i++)
2716 if (page_address(area->pages[i]))
2717 set_direct_map(area->pages[i]);
2718}
2719
2720/*
2721 * Flush the vm mapping and reset the direct map.
2722 */
2723static void vm_reset_perms(struct vm_struct *area)
2724{
2725 unsigned long start = ULONG_MAX, end = 0;
2726 unsigned int page_order = vm_area_page_order(area);
2727 int flush_dmap = 0;
2728 int i;
2729
2730 /*
2731 * Find the start and end range of the direct mappings to make sure that
2732 * the vm_unmap_aliases() flush includes the direct map.
2733 */
2734 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
2735 unsigned long addr = (unsigned long)page_address(area->pages[i]);
2736
2737 if (addr) {
2738 unsigned long page_size;
2739
2740 page_size = PAGE_SIZE << page_order;
2741 start = min(addr, start);
2742 end = max(addr + page_size, end);
2743 flush_dmap = 1;
2744 }
2745 }
2746
2747 /*
2748 * Set direct map to something invalid so that it won't be cached if
2749 * there are any accesses after the TLB flush, then flush the TLB and
2750 * reset the direct map permissions to the default.
2751 */
2752 set_area_direct_map(area, set_direct_map_invalid_noflush);
2753 _vm_unmap_aliases(start, end, flush_dmap);
2754 set_area_direct_map(area, set_direct_map_default_noflush);
2755}
2756
2757static void delayed_vfree_work(struct work_struct *w)
2758{
2759 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
2760 struct llist_node *t, *llnode;
2761
2762 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
2763 vfree(llnode);
2764}
2765
2766/**
2767 * vfree_atomic - release memory allocated by vmalloc()
2768 * @addr: memory base address
2769 *
2770 * This one is just like vfree() but can be called in any atomic context
2771 * except NMIs.
2772 */
2773void vfree_atomic(const void *addr)
2774{
2775 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
2776
2777 BUG_ON(in_nmi());
2778 kmemleak_free(addr);
2779
2780 /*
2781 * Use raw_cpu_ptr() because this can be called from preemptible
2782 * context. Preemption is absolutely fine here, because the llist_add()
2783 * implementation is lockless, so it works even if we are adding to
2784 * another cpu's list. schedule_work() should be fine with this too.
2785 */
2786 if (addr && llist_add((struct llist_node *)addr, &p->list))
2787 schedule_work(&p->wq);
2788}
2789
2790/**
2791 * vfree - Release memory allocated by vmalloc()
2792 * @addr: Memory base address
2793 *
2794 * Free the virtually continuous memory area starting at @addr, as obtained
2795 * from one of the vmalloc() family of APIs. This will usually also free the
2796 * physical memory underlying the virtual allocation, but that memory is
2797 * reference counted, so it will not be freed until the last user goes away.
2798 *
2799 * If @addr is NULL, no operation is performed.
2800 *
2801 * Context:
2802 * May sleep if called *not* from interrupt context.
2803 * Must not be called in NMI context (strictly speaking, it could be
2804 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
2805 * conventions for vfree() arch-dependent would be a really bad idea).
2806 */
2807void vfree(const void *addr)
2808{
2809 struct vm_struct *vm;
2810 int i;
2811
2812 if (unlikely(in_interrupt())) {
2813 vfree_atomic(addr);
2814 return;
2815 }
2816
2817 BUG_ON(in_nmi());
2818 kmemleak_free(addr);
2819 might_sleep();
2820
2821 if (!addr)
2822 return;
2823
2824 vm = remove_vm_area(addr);
2825 if (unlikely(!vm)) {
2826 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
2827 addr);
2828 return;
2829 }
2830
2831 if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
2832 vm_reset_perms(vm);
2833 for (i = 0; i < vm->nr_pages; i++) {
2834 struct page *page = vm->pages[i];
2835
2836 BUG_ON(!page);
2837 mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
2838 /*
2839 * High-order allocs for huge vmallocs are split, so
2840 * can be freed as an array of order-0 allocations
2841 */
2842 __free_page(page);
2843 cond_resched();
2844 }
2845 atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages);
2846 kvfree(vm->pages);
2847 kfree(vm);
2848}
2849EXPORT_SYMBOL(vfree);
2850
2851/**
2852 * vunmap - release virtual mapping obtained by vmap()
2853 * @addr: memory base address
2854 *
2855 * Free the virtually contiguous memory area starting at @addr,
2856 * which was created from the page array passed to vmap().
2857 *
2858 * Must not be called in interrupt context.
2859 */
2860void vunmap(const void *addr)
2861{
2862 struct vm_struct *vm;
2863
2864 BUG_ON(in_interrupt());
2865 might_sleep();
2866
2867 if (!addr)
2868 return;
2869 vm = remove_vm_area(addr);
2870 if (unlikely(!vm)) {
2871 WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n",
2872 addr);
2873 return;
2874 }
2875 kfree(vm);
2876}
2877EXPORT_SYMBOL(vunmap);
2878
2879/**
2880 * vmap - map an array of pages into virtually contiguous space
2881 * @pages: array of page pointers
2882 * @count: number of pages to map
2883 * @flags: vm_area->flags
2884 * @prot: page protection for the mapping
2885 *
2886 * Maps @count pages from @pages into contiguous kernel virtual space.
2887 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
2888 * (which must be kmalloc or vmalloc memory) and one reference per pages in it
2889 * are transferred from the caller to vmap(), and will be freed / dropped when
2890 * vfree() is called on the return value.
2891 *
2892 * Return: the address of the area or %NULL on failure
2893 */
2894void *vmap(struct page **pages, unsigned int count,
2895 unsigned long flags, pgprot_t prot)
2896{
2897 struct vm_struct *area;
2898 unsigned long addr;
2899 unsigned long size; /* In bytes */
2900
2901 might_sleep();
2902
2903 if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS))
2904 return NULL;
2905
2906 /*
2907 * Your top guard is someone else's bottom guard. Not having a top
2908 * guard compromises someone else's mappings too.
2909 */
2910 if (WARN_ON_ONCE(flags & VM_NO_GUARD))
2911 flags &= ~VM_NO_GUARD;
2912
2913 if (count > totalram_pages())
2914 return NULL;
2915
2916 size = (unsigned long)count << PAGE_SHIFT;
2917 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
2918 if (!area)
2919 return NULL;
2920
2921 addr = (unsigned long)area->addr;
2922 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
2923 pages, PAGE_SHIFT) < 0) {
2924 vunmap(area->addr);
2925 return NULL;
2926 }
2927
2928 if (flags & VM_MAP_PUT_PAGES) {
2929 area->pages = pages;
2930 area->nr_pages = count;
2931 }
2932 return area->addr;
2933}
2934EXPORT_SYMBOL(vmap);
2935
2936#ifdef CONFIG_VMAP_PFN
2937struct vmap_pfn_data {
2938 unsigned long *pfns;
2939 pgprot_t prot;
2940 unsigned int idx;
2941};
2942
2943static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
2944{
2945 struct vmap_pfn_data *data = private;
2946 unsigned long pfn = data->pfns[data->idx];
2947 pte_t ptent;
2948
2949 if (WARN_ON_ONCE(pfn_valid(pfn)))
2950 return -EINVAL;
2951
2952 ptent = pte_mkspecial(pfn_pte(pfn, data->prot));
2953 set_pte_at(&init_mm, addr, pte, ptent);
2954
2955 data->idx++;
2956 return 0;
2957}
2958
2959/**
2960 * vmap_pfn - map an array of PFNs into virtually contiguous space
2961 * @pfns: array of PFNs
2962 * @count: number of pages to map
2963 * @prot: page protection for the mapping
2964 *
2965 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
2966 * the start address of the mapping.
2967 */
2968void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
2969{
2970 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) };
2971 struct vm_struct *area;
2972
2973 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP,
2974 __builtin_return_address(0));
2975 if (!area)
2976 return NULL;
2977 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2978 count * PAGE_SIZE, vmap_pfn_apply, &data)) {
2979 free_vm_area(area);
2980 return NULL;
2981 }
2982
2983 flush_cache_vmap((unsigned long)area->addr,
2984 (unsigned long)area->addr + count * PAGE_SIZE);
2985
2986 return area->addr;
2987}
2988EXPORT_SYMBOL_GPL(vmap_pfn);
2989#endif /* CONFIG_VMAP_PFN */
2990
2991static inline unsigned int
2992vm_area_alloc_pages(gfp_t gfp, int nid,
2993 unsigned int order, unsigned int nr_pages, struct page **pages)
2994{
2995 unsigned int nr_allocated = 0;
2996 gfp_t alloc_gfp = gfp;
2997 bool nofail = false;
2998 struct page *page;
2999 int i;
3000
3001 /*
3002 * For order-0 pages we make use of bulk allocator, if
3003 * the page array is partly or not at all populated due
3004 * to fails, fallback to a single page allocator that is
3005 * more permissive.
3006 */
3007 if (!order) {
3008 /* bulk allocator doesn't support nofail req. officially */
3009 gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL;
3010
3011 while (nr_allocated < nr_pages) {
3012 unsigned int nr, nr_pages_request;
3013
3014 /*
3015 * A maximum allowed request is hard-coded and is 100
3016 * pages per call. That is done in order to prevent a
3017 * long preemption off scenario in the bulk-allocator
3018 * so the range is [1:100].
3019 */
3020 nr_pages_request = min(100U, nr_pages - nr_allocated);
3021
3022 /* memory allocation should consider mempolicy, we can't
3023 * wrongly use nearest node when nid == NUMA_NO_NODE,
3024 * otherwise memory may be allocated in only one node,
3025 * but mempolicy wants to alloc memory by interleaving.
3026 */
3027 if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE)
3028 nr = alloc_pages_bulk_array_mempolicy(bulk_gfp,
3029 nr_pages_request,
3030 pages + nr_allocated);
3031
3032 else
3033 nr = alloc_pages_bulk_array_node(bulk_gfp, nid,
3034 nr_pages_request,
3035 pages + nr_allocated);
3036
3037 nr_allocated += nr;
3038 cond_resched();
3039
3040 /*
3041 * If zero or pages were obtained partly,
3042 * fallback to a single page allocator.
3043 */
3044 if (nr != nr_pages_request)
3045 break;
3046 }
3047 } else if (gfp & __GFP_NOFAIL) {
3048 /*
3049 * Higher order nofail allocations are really expensive and
3050 * potentially dangerous (pre-mature OOM, disruptive reclaim
3051 * and compaction etc.
3052 */
3053 alloc_gfp &= ~__GFP_NOFAIL;
3054 nofail = true;
3055 }
3056
3057 /* High-order pages or fallback path if "bulk" fails. */
3058 while (nr_allocated < nr_pages) {
3059 if (fatal_signal_pending(current))
3060 break;
3061
3062 if (nid == NUMA_NO_NODE)
3063 page = alloc_pages(alloc_gfp, order);
3064 else
3065 page = alloc_pages_node(nid, alloc_gfp, order);
3066 if (unlikely(!page)) {
3067 if (!nofail)
3068 break;
3069
3070 /* fall back to the zero order allocations */
3071 alloc_gfp |= __GFP_NOFAIL;
3072 order = 0;
3073 continue;
3074 }
3075
3076 /*
3077 * Higher order allocations must be able to be treated as
3078 * indepdenent small pages by callers (as they can with
3079 * small-page vmallocs). Some drivers do their own refcounting
3080 * on vmalloc_to_page() pages, some use page->mapping,
3081 * page->lru, etc.
3082 */
3083 if (order)
3084 split_page(page, order);
3085
3086 /*
3087 * Careful, we allocate and map page-order pages, but
3088 * tracking is done per PAGE_SIZE page so as to keep the
3089 * vm_struct APIs independent of the physical/mapped size.
3090 */
3091 for (i = 0; i < (1U << order); i++)
3092 pages[nr_allocated + i] = page + i;
3093
3094 cond_resched();
3095 nr_allocated += 1U << order;
3096 }
3097
3098 return nr_allocated;
3099}
3100
3101static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
3102 pgprot_t prot, unsigned int page_shift,
3103 int node)
3104{
3105 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
3106 bool nofail = gfp_mask & __GFP_NOFAIL;
3107 unsigned long addr = (unsigned long)area->addr;
3108 unsigned long size = get_vm_area_size(area);
3109 unsigned long array_size;
3110 unsigned int nr_small_pages = size >> PAGE_SHIFT;
3111 unsigned int page_order;
3112 unsigned int flags;
3113 int ret;
3114
3115 array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
3116
3117 if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
3118 gfp_mask |= __GFP_HIGHMEM;
3119
3120 /* Please note that the recursion is strictly bounded. */
3121 if (array_size > PAGE_SIZE) {
3122 area->pages = __vmalloc_node(array_size, 1, nested_gfp, node,
3123 area->caller);
3124 } else {
3125 area->pages = kmalloc_node(array_size, nested_gfp, node);
3126 }
3127
3128 if (!area->pages) {
3129 warn_alloc(gfp_mask, NULL,
3130 "vmalloc error: size %lu, failed to allocated page array size %lu",
3131 nr_small_pages * PAGE_SIZE, array_size);
3132 free_vm_area(area);
3133 return NULL;
3134 }
3135
3136 set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
3137 page_order = vm_area_page_order(area);
3138
3139 area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN,
3140 node, page_order, nr_small_pages, area->pages);
3141
3142 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
3143 if (gfp_mask & __GFP_ACCOUNT) {
3144 int i;
3145
3146 for (i = 0; i < area->nr_pages; i++)
3147 mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1);
3148 }
3149
3150 /*
3151 * If not enough pages were obtained to accomplish an
3152 * allocation request, free them via vfree() if any.
3153 */
3154 if (area->nr_pages != nr_small_pages) {
3155 /*
3156 * vm_area_alloc_pages() can fail due to insufficient memory but
3157 * also:-
3158 *
3159 * - a pending fatal signal
3160 * - insufficient huge page-order pages
3161 *
3162 * Since we always retry allocations at order-0 in the huge page
3163 * case a warning for either is spurious.
3164 */
3165 if (!fatal_signal_pending(current) && page_order == 0)
3166 warn_alloc(gfp_mask, NULL,
3167 "vmalloc error: size %lu, failed to allocate pages",
3168 area->nr_pages * PAGE_SIZE);
3169 goto fail;
3170 }
3171
3172 /*
3173 * page tables allocations ignore external gfp mask, enforce it
3174 * by the scope API
3175 */
3176 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3177 flags = memalloc_nofs_save();
3178 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3179 flags = memalloc_noio_save();
3180
3181 do {
3182 ret = vmap_pages_range(addr, addr + size, prot, area->pages,
3183 page_shift);
3184 if (nofail && (ret < 0))
3185 schedule_timeout_uninterruptible(1);
3186 } while (nofail && (ret < 0));
3187
3188 if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
3189 memalloc_nofs_restore(flags);
3190 else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
3191 memalloc_noio_restore(flags);
3192
3193 if (ret < 0) {
3194 warn_alloc(gfp_mask, NULL,
3195 "vmalloc error: size %lu, failed to map pages",
3196 area->nr_pages * PAGE_SIZE);
3197 goto fail;
3198 }
3199
3200 return area->addr;
3201
3202fail:
3203 vfree(area->addr);
3204 return NULL;
3205}
3206
3207/**
3208 * __vmalloc_node_range - allocate virtually contiguous memory
3209 * @size: allocation size
3210 * @align: desired alignment
3211 * @start: vm area range start
3212 * @end: vm area range end
3213 * @gfp_mask: flags for the page level allocator
3214 * @prot: protection mask for the allocated pages
3215 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
3216 * @node: node to use for allocation or NUMA_NO_NODE
3217 * @caller: caller's return address
3218 *
3219 * Allocate enough pages to cover @size from the page level
3220 * allocator with @gfp_mask flags. Please note that the full set of gfp
3221 * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all
3222 * supported.
3223 * Zone modifiers are not supported. From the reclaim modifiers
3224 * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported)
3225 * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and
3226 * __GFP_RETRY_MAYFAIL are not supported).
3227 *
3228 * __GFP_NOWARN can be used to suppress failures messages.
3229 *
3230 * Map them into contiguous kernel virtual space, using a pagetable
3231 * protection of @prot.
3232 *
3233 * Return: the address of the area or %NULL on failure
3234 */
3235void *__vmalloc_node_range(unsigned long size, unsigned long align,
3236 unsigned long start, unsigned long end, gfp_t gfp_mask,
3237 pgprot_t prot, unsigned long vm_flags, int node,
3238 const void *caller)
3239{
3240 struct vm_struct *area;
3241 void *ret;
3242 kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE;
3243 unsigned long real_size = size;
3244 unsigned long real_align = align;
3245 unsigned int shift = PAGE_SHIFT;
3246
3247 if (WARN_ON_ONCE(!size))
3248 return NULL;
3249
3250 if ((size >> PAGE_SHIFT) > totalram_pages()) {
3251 warn_alloc(gfp_mask, NULL,
3252 "vmalloc error: size %lu, exceeds total pages",
3253 real_size);
3254 return NULL;
3255 }
3256
3257 if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) {
3258 unsigned long size_per_node;
3259
3260 /*
3261 * Try huge pages. Only try for PAGE_KERNEL allocations,
3262 * others like modules don't yet expect huge pages in
3263 * their allocations due to apply_to_page_range not
3264 * supporting them.
3265 */
3266
3267 size_per_node = size;
3268 if (node == NUMA_NO_NODE)
3269 size_per_node /= num_online_nodes();
3270 if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
3271 shift = PMD_SHIFT;
3272 else
3273 shift = arch_vmap_pte_supported_shift(size_per_node);
3274
3275 align = max(real_align, 1UL << shift);
3276 size = ALIGN(real_size, 1UL << shift);
3277 }
3278
3279again:
3280 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
3281 VM_UNINITIALIZED | vm_flags, start, end, node,
3282 gfp_mask, caller);
3283 if (!area) {
3284 bool nofail = gfp_mask & __GFP_NOFAIL;
3285 warn_alloc(gfp_mask, NULL,
3286 "vmalloc error: size %lu, vm_struct allocation failed%s",
3287 real_size, (nofail) ? ". Retrying." : "");
3288 if (nofail) {
3289 schedule_timeout_uninterruptible(1);
3290 goto again;
3291 }
3292 goto fail;
3293 }
3294
3295 /*
3296 * Prepare arguments for __vmalloc_area_node() and
3297 * kasan_unpoison_vmalloc().
3298 */
3299 if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) {
3300 if (kasan_hw_tags_enabled()) {
3301 /*
3302 * Modify protection bits to allow tagging.
3303 * This must be done before mapping.
3304 */
3305 prot = arch_vmap_pgprot_tagged(prot);
3306
3307 /*
3308 * Skip page_alloc poisoning and zeroing for physical
3309 * pages backing VM_ALLOC mapping. Memory is instead
3310 * poisoned and zeroed by kasan_unpoison_vmalloc().
3311 */
3312 gfp_mask |= __GFP_SKIP_KASAN | __GFP_SKIP_ZERO;
3313 }
3314
3315 /* Take note that the mapping is PAGE_KERNEL. */
3316 kasan_flags |= KASAN_VMALLOC_PROT_NORMAL;
3317 }
3318
3319 /* Allocate physical pages and map them into vmalloc space. */
3320 ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
3321 if (!ret)
3322 goto fail;
3323
3324 /*
3325 * Mark the pages as accessible, now that they are mapped.
3326 * The condition for setting KASAN_VMALLOC_INIT should complement the
3327 * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check
3328 * to make sure that memory is initialized under the same conditions.
3329 * Tag-based KASAN modes only assign tags to normal non-executable
3330 * allocations, see __kasan_unpoison_vmalloc().
3331 */
3332 kasan_flags |= KASAN_VMALLOC_VM_ALLOC;
3333 if (!want_init_on_free() && want_init_on_alloc(gfp_mask) &&
3334 (gfp_mask & __GFP_SKIP_ZERO))
3335 kasan_flags |= KASAN_VMALLOC_INIT;
3336 /* KASAN_VMALLOC_PROT_NORMAL already set if required. */
3337 area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags);
3338
3339 /*
3340 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
3341 * flag. It means that vm_struct is not fully initialized.
3342 * Now, it is fully initialized, so remove this flag here.
3343 */
3344 clear_vm_uninitialized_flag(area);
3345
3346 size = PAGE_ALIGN(size);
3347 if (!(vm_flags & VM_DEFER_KMEMLEAK))
3348 kmemleak_vmalloc(area, size, gfp_mask);
3349
3350 return area->addr;
3351
3352fail:
3353 if (shift > PAGE_SHIFT) {
3354 shift = PAGE_SHIFT;
3355 align = real_align;
3356 size = real_size;
3357 goto again;
3358 }
3359
3360 return NULL;
3361}
3362
3363/**
3364 * __vmalloc_node - allocate virtually contiguous memory
3365 * @size: allocation size
3366 * @align: desired alignment
3367 * @gfp_mask: flags for the page level allocator
3368 * @node: node to use for allocation or NUMA_NO_NODE
3369 * @caller: caller's return address
3370 *
3371 * Allocate enough pages to cover @size from the page level allocator with
3372 * @gfp_mask flags. Map them into contiguous kernel virtual space.
3373 *
3374 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
3375 * and __GFP_NOFAIL are not supported
3376 *
3377 * Any use of gfp flags outside of GFP_KERNEL should be consulted
3378 * with mm people.
3379 *
3380 * Return: pointer to the allocated memory or %NULL on error
3381 */
3382void *__vmalloc_node(unsigned long size, unsigned long align,
3383 gfp_t gfp_mask, int node, const void *caller)
3384{
3385 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
3386 gfp_mask, PAGE_KERNEL, 0, node, caller);
3387}
3388/*
3389 * This is only for performance analysis of vmalloc and stress purpose.
3390 * It is required by vmalloc test module, therefore do not use it other
3391 * than that.
3392 */
3393#ifdef CONFIG_TEST_VMALLOC_MODULE
3394EXPORT_SYMBOL_GPL(__vmalloc_node);
3395#endif
3396
3397void *__vmalloc(unsigned long size, gfp_t gfp_mask)
3398{
3399 return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE,
3400 __builtin_return_address(0));
3401}
3402EXPORT_SYMBOL(__vmalloc);
3403
3404/**
3405 * vmalloc - allocate virtually contiguous memory
3406 * @size: allocation size
3407 *
3408 * Allocate enough pages to cover @size from the page level
3409 * allocator and map them into contiguous kernel virtual space.
3410 *
3411 * For tight control over page level allocator and protection flags
3412 * use __vmalloc() instead.
3413 *
3414 * Return: pointer to the allocated memory or %NULL on error
3415 */
3416void *vmalloc(unsigned long size)
3417{
3418 return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE,
3419 __builtin_return_address(0));
3420}
3421EXPORT_SYMBOL(vmalloc);
3422
3423/**
3424 * vmalloc_huge - allocate virtually contiguous memory, allow huge pages
3425 * @size: allocation size
3426 * @gfp_mask: flags for the page level allocator
3427 *
3428 * Allocate enough pages to cover @size from the page level
3429 * allocator and map them into contiguous kernel virtual space.
3430 * If @size is greater than or equal to PMD_SIZE, allow using
3431 * huge pages for the memory
3432 *
3433 * Return: pointer to the allocated memory or %NULL on error
3434 */
3435void *vmalloc_huge(unsigned long size, gfp_t gfp_mask)
3436{
3437 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
3438 gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP,
3439 NUMA_NO_NODE, __builtin_return_address(0));
3440}
3441EXPORT_SYMBOL_GPL(vmalloc_huge);
3442
3443/**
3444 * vzalloc - allocate virtually contiguous memory with zero fill
3445 * @size: allocation size
3446 *
3447 * Allocate enough pages to cover @size from the page level
3448 * allocator and map them into contiguous kernel virtual space.
3449 * The memory allocated is set to zero.
3450 *
3451 * For tight control over page level allocator and protection flags
3452 * use __vmalloc() instead.
3453 *
3454 * Return: pointer to the allocated memory or %NULL on error
3455 */
3456void *vzalloc(unsigned long size)
3457{
3458 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE,
3459 __builtin_return_address(0));
3460}
3461EXPORT_SYMBOL(vzalloc);
3462
3463/**
3464 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
3465 * @size: allocation size
3466 *
3467 * The resulting memory area is zeroed so it can be mapped to userspace
3468 * without leaking data.
3469 *
3470 * Return: pointer to the allocated memory or %NULL on error
3471 */
3472void *vmalloc_user(unsigned long size)
3473{
3474 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3475 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
3476 VM_USERMAP, NUMA_NO_NODE,
3477 __builtin_return_address(0));
3478}
3479EXPORT_SYMBOL(vmalloc_user);
3480
3481/**
3482 * vmalloc_node - allocate memory on a specific node
3483 * @size: allocation size
3484 * @node: numa node
3485 *
3486 * Allocate enough pages to cover @size from the page level
3487 * allocator and map them into contiguous kernel virtual space.
3488 *
3489 * For tight control over page level allocator and protection flags
3490 * use __vmalloc() instead.
3491 *
3492 * Return: pointer to the allocated memory or %NULL on error
3493 */
3494void *vmalloc_node(unsigned long size, int node)
3495{
3496 return __vmalloc_node(size, 1, GFP_KERNEL, node,
3497 __builtin_return_address(0));
3498}
3499EXPORT_SYMBOL(vmalloc_node);
3500
3501/**
3502 * vzalloc_node - allocate memory on a specific node with zero fill
3503 * @size: allocation size
3504 * @node: numa node
3505 *
3506 * Allocate enough pages to cover @size from the page level
3507 * allocator and map them into contiguous kernel virtual space.
3508 * The memory allocated is set to zero.
3509 *
3510 * Return: pointer to the allocated memory or %NULL on error
3511 */
3512void *vzalloc_node(unsigned long size, int node)
3513{
3514 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node,
3515 __builtin_return_address(0));
3516}
3517EXPORT_SYMBOL(vzalloc_node);
3518
3519#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
3520#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3521#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
3522#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
3523#else
3524/*
3525 * 64b systems should always have either DMA or DMA32 zones. For others
3526 * GFP_DMA32 should do the right thing and use the normal zone.
3527 */
3528#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3529#endif
3530
3531/**
3532 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
3533 * @size: allocation size
3534 *
3535 * Allocate enough 32bit PA addressable pages to cover @size from the
3536 * page level allocator and map them into contiguous kernel virtual space.
3537 *
3538 * Return: pointer to the allocated memory or %NULL on error
3539 */
3540void *vmalloc_32(unsigned long size)
3541{
3542 return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE,
3543 __builtin_return_address(0));
3544}
3545EXPORT_SYMBOL(vmalloc_32);
3546
3547/**
3548 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
3549 * @size: allocation size
3550 *
3551 * The resulting memory area is 32bit addressable and zeroed so it can be
3552 * mapped to userspace without leaking data.
3553 *
3554 * Return: pointer to the allocated memory or %NULL on error
3555 */
3556void *vmalloc_32_user(unsigned long size)
3557{
3558 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3559 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
3560 VM_USERMAP, NUMA_NO_NODE,
3561 __builtin_return_address(0));
3562}
3563EXPORT_SYMBOL(vmalloc_32_user);
3564
3565/*
3566 * Atomically zero bytes in the iterator.
3567 *
3568 * Returns the number of zeroed bytes.
3569 */
3570static size_t zero_iter(struct iov_iter *iter, size_t count)
3571{
3572 size_t remains = count;
3573
3574 while (remains > 0) {
3575 size_t num, copied;
3576
3577 num = min_t(size_t, remains, PAGE_SIZE);
3578 copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter);
3579 remains -= copied;
3580
3581 if (copied < num)
3582 break;
3583 }
3584
3585 return count - remains;
3586}
3587
3588/*
3589 * small helper routine, copy contents to iter from addr.
3590 * If the page is not present, fill zero.
3591 *
3592 * Returns the number of copied bytes.
3593 */
3594static size_t aligned_vread_iter(struct iov_iter *iter,
3595 const char *addr, size_t count)
3596{
3597 size_t remains = count;
3598 struct page *page;
3599
3600 while (remains > 0) {
3601 unsigned long offset, length;
3602 size_t copied = 0;
3603
3604 offset = offset_in_page(addr);
3605 length = PAGE_SIZE - offset;
3606 if (length > remains)
3607 length = remains;
3608 page = vmalloc_to_page(addr);
3609 /*
3610 * To do safe access to this _mapped_ area, we need lock. But
3611 * adding lock here means that we need to add overhead of
3612 * vmalloc()/vfree() calls for this _debug_ interface, rarely
3613 * used. Instead of that, we'll use an local mapping via
3614 * copy_page_to_iter_nofault() and accept a small overhead in
3615 * this access function.
3616 */
3617 if (page)
3618 copied = copy_page_to_iter_nofault(page, offset,
3619 length, iter);
3620 else
3621 copied = zero_iter(iter, length);
3622
3623 addr += copied;
3624 remains -= copied;
3625
3626 if (copied != length)
3627 break;
3628 }
3629
3630 return count - remains;
3631}
3632
3633/*
3634 * Read from a vm_map_ram region of memory.
3635 *
3636 * Returns the number of copied bytes.
3637 */
3638static size_t vmap_ram_vread_iter(struct iov_iter *iter, const char *addr,
3639 size_t count, unsigned long flags)
3640{
3641 char *start;
3642 struct vmap_block *vb;
3643 struct xarray *xa;
3644 unsigned long offset;
3645 unsigned int rs, re;
3646 size_t remains, n;
3647
3648 /*
3649 * If it's area created by vm_map_ram() interface directly, but
3650 * not further subdividing and delegating management to vmap_block,
3651 * handle it here.
3652 */
3653 if (!(flags & VMAP_BLOCK))
3654 return aligned_vread_iter(iter, addr, count);
3655
3656 remains = count;
3657
3658 /*
3659 * Area is split into regions and tracked with vmap_block, read out
3660 * each region and zero fill the hole between regions.
3661 */
3662 xa = addr_to_vb_xa((unsigned long) addr);
3663 vb = xa_load(xa, addr_to_vb_idx((unsigned long)addr));
3664 if (!vb)
3665 goto finished_zero;
3666
3667 spin_lock(&vb->lock);
3668 if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) {
3669 spin_unlock(&vb->lock);
3670 goto finished_zero;
3671 }
3672
3673 for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) {
3674 size_t copied;
3675
3676 if (remains == 0)
3677 goto finished;
3678
3679 start = vmap_block_vaddr(vb->va->va_start, rs);
3680
3681 if (addr < start) {
3682 size_t to_zero = min_t(size_t, start - addr, remains);
3683 size_t zeroed = zero_iter(iter, to_zero);
3684
3685 addr += zeroed;
3686 remains -= zeroed;
3687
3688 if (remains == 0 || zeroed != to_zero)
3689 goto finished;
3690 }
3691
3692 /*it could start reading from the middle of used region*/
3693 offset = offset_in_page(addr);
3694 n = ((re - rs + 1) << PAGE_SHIFT) - offset;
3695 if (n > remains)
3696 n = remains;
3697
3698 copied = aligned_vread_iter(iter, start + offset, n);
3699
3700 addr += copied;
3701 remains -= copied;
3702
3703 if (copied != n)
3704 goto finished;
3705 }
3706
3707 spin_unlock(&vb->lock);
3708
3709finished_zero:
3710 /* zero-fill the left dirty or free regions */
3711 return count - remains + zero_iter(iter, remains);
3712finished:
3713 /* We couldn't copy/zero everything */
3714 spin_unlock(&vb->lock);
3715 return count - remains;
3716}
3717
3718/**
3719 * vread_iter() - read vmalloc area in a safe way to an iterator.
3720 * @iter: the iterator to which data should be written.
3721 * @addr: vm address.
3722 * @count: number of bytes to be read.
3723 *
3724 * This function checks that addr is a valid vmalloc'ed area, and
3725 * copy data from that area to a given buffer. If the given memory range
3726 * of [addr...addr+count) includes some valid address, data is copied to
3727 * proper area of @buf. If there are memory holes, they'll be zero-filled.
3728 * IOREMAP area is treated as memory hole and no copy is done.
3729 *
3730 * If [addr...addr+count) doesn't includes any intersects with alive
3731 * vm_struct area, returns 0. @buf should be kernel's buffer.
3732 *
3733 * Note: In usual ops, vread() is never necessary because the caller
3734 * should know vmalloc() area is valid and can use memcpy().
3735 * This is for routines which have to access vmalloc area without
3736 * any information, as /proc/kcore.
3737 *
3738 * Return: number of bytes for which addr and buf should be increased
3739 * (same number as @count) or %0 if [addr...addr+count) doesn't
3740 * include any intersection with valid vmalloc area
3741 */
3742long vread_iter(struct iov_iter *iter, const char *addr, size_t count)
3743{
3744 struct vmap_area *va;
3745 struct vm_struct *vm;
3746 char *vaddr;
3747 size_t n, size, flags, remains;
3748
3749 addr = kasan_reset_tag(addr);
3750
3751 /* Don't allow overflow */
3752 if ((unsigned long) addr + count < count)
3753 count = -(unsigned long) addr;
3754
3755 remains = count;
3756
3757 spin_lock(&vmap_area_lock);
3758 va = find_vmap_area_exceed_addr((unsigned long)addr);
3759 if (!va)
3760 goto finished_zero;
3761
3762 /* no intersects with alive vmap_area */
3763 if ((unsigned long)addr + remains <= va->va_start)
3764 goto finished_zero;
3765
3766 list_for_each_entry_from(va, &vmap_area_list, list) {
3767 size_t copied;
3768
3769 if (remains == 0)
3770 goto finished;
3771
3772 vm = va->vm;
3773 flags = va->flags & VMAP_FLAGS_MASK;
3774 /*
3775 * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need
3776 * be set together with VMAP_RAM.
3777 */
3778 WARN_ON(flags == VMAP_BLOCK);
3779
3780 if (!vm && !flags)
3781 continue;
3782
3783 if (vm && (vm->flags & VM_UNINITIALIZED))
3784 continue;
3785
3786 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
3787 smp_rmb();
3788
3789 vaddr = (char *) va->va_start;
3790 size = vm ? get_vm_area_size(vm) : va_size(va);
3791
3792 if (addr >= vaddr + size)
3793 continue;
3794
3795 if (addr < vaddr) {
3796 size_t to_zero = min_t(size_t, vaddr - addr, remains);
3797 size_t zeroed = zero_iter(iter, to_zero);
3798
3799 addr += zeroed;
3800 remains -= zeroed;
3801
3802 if (remains == 0 || zeroed != to_zero)
3803 goto finished;
3804 }
3805
3806 n = vaddr + size - addr;
3807 if (n > remains)
3808 n = remains;
3809
3810 if (flags & VMAP_RAM)
3811 copied = vmap_ram_vread_iter(iter, addr, n, flags);
3812 else if (!(vm && (vm->flags & VM_IOREMAP)))
3813 copied = aligned_vread_iter(iter, addr, n);
3814 else /* IOREMAP area is treated as memory hole */
3815 copied = zero_iter(iter, n);
3816
3817 addr += copied;
3818 remains -= copied;
3819
3820 if (copied != n)
3821 goto finished;
3822 }
3823
3824finished_zero:
3825 spin_unlock(&vmap_area_lock);
3826 /* zero-fill memory holes */
3827 return count - remains + zero_iter(iter, remains);
3828finished:
3829 /* Nothing remains, or We couldn't copy/zero everything. */
3830 spin_unlock(&vmap_area_lock);
3831
3832 return count - remains;
3833}
3834
3835/**
3836 * remap_vmalloc_range_partial - map vmalloc pages to userspace
3837 * @vma: vma to cover
3838 * @uaddr: target user address to start at
3839 * @kaddr: virtual address of vmalloc kernel memory
3840 * @pgoff: offset from @kaddr to start at
3841 * @size: size of map area
3842 *
3843 * Returns: 0 for success, -Exxx on failure
3844 *
3845 * This function checks that @kaddr is a valid vmalloc'ed area,
3846 * and that it is big enough to cover the range starting at
3847 * @uaddr in @vma. Will return failure if that criteria isn't
3848 * met.
3849 *
3850 * Similar to remap_pfn_range() (see mm/memory.c)
3851 */
3852int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
3853 void *kaddr, unsigned long pgoff,
3854 unsigned long size)
3855{
3856 struct vm_struct *area;
3857 unsigned long off;
3858 unsigned long end_index;
3859
3860 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off))
3861 return -EINVAL;
3862
3863 size = PAGE_ALIGN(size);
3864
3865 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
3866 return -EINVAL;
3867
3868 area = find_vm_area(kaddr);
3869 if (!area)
3870 return -EINVAL;
3871
3872 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
3873 return -EINVAL;
3874
3875 if (check_add_overflow(size, off, &end_index) ||
3876 end_index > get_vm_area_size(area))
3877 return -EINVAL;
3878 kaddr += off;
3879
3880 do {
3881 struct page *page = vmalloc_to_page(kaddr);
3882 int ret;
3883
3884 ret = vm_insert_page(vma, uaddr, page);
3885 if (ret)
3886 return ret;
3887
3888 uaddr += PAGE_SIZE;
3889 kaddr += PAGE_SIZE;
3890 size -= PAGE_SIZE;
3891 } while (size > 0);
3892
3893 vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
3894
3895 return 0;
3896}
3897
3898/**
3899 * remap_vmalloc_range - map vmalloc pages to userspace
3900 * @vma: vma to cover (map full range of vma)
3901 * @addr: vmalloc memory
3902 * @pgoff: number of pages into addr before first page to map
3903 *
3904 * Returns: 0 for success, -Exxx on failure
3905 *
3906 * This function checks that addr is a valid vmalloc'ed area, and
3907 * that it is big enough to cover the vma. Will return failure if
3908 * that criteria isn't met.
3909 *
3910 * Similar to remap_pfn_range() (see mm/memory.c)
3911 */
3912int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
3913 unsigned long pgoff)
3914{
3915 return remap_vmalloc_range_partial(vma, vma->vm_start,
3916 addr, pgoff,
3917 vma->vm_end - vma->vm_start);
3918}
3919EXPORT_SYMBOL(remap_vmalloc_range);
3920
3921void free_vm_area(struct vm_struct *area)
3922{
3923 struct vm_struct *ret;
3924 ret = remove_vm_area(area->addr);
3925 BUG_ON(ret != area);
3926 kfree(area);
3927}
3928EXPORT_SYMBOL_GPL(free_vm_area);
3929
3930#ifdef CONFIG_SMP
3931static struct vmap_area *node_to_va(struct rb_node *n)
3932{
3933 return rb_entry_safe(n, struct vmap_area, rb_node);
3934}
3935
3936/**
3937 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
3938 * @addr: target address
3939 *
3940 * Returns: vmap_area if it is found. If there is no such area
3941 * the first highest(reverse order) vmap_area is returned
3942 * i.e. va->va_start < addr && va->va_end < addr or NULL
3943 * if there are no any areas before @addr.
3944 */
3945static struct vmap_area *
3946pvm_find_va_enclose_addr(unsigned long addr)
3947{
3948 struct vmap_area *va, *tmp;
3949 struct rb_node *n;
3950
3951 n = free_vmap_area_root.rb_node;
3952 va = NULL;
3953
3954 while (n) {
3955 tmp = rb_entry(n, struct vmap_area, rb_node);
3956 if (tmp->va_start <= addr) {
3957 va = tmp;
3958 if (tmp->va_end >= addr)
3959 break;
3960
3961 n = n->rb_right;
3962 } else {
3963 n = n->rb_left;
3964 }
3965 }
3966
3967 return va;
3968}
3969
3970/**
3971 * pvm_determine_end_from_reverse - find the highest aligned address
3972 * of free block below VMALLOC_END
3973 * @va:
3974 * in - the VA we start the search(reverse order);
3975 * out - the VA with the highest aligned end address.
3976 * @align: alignment for required highest address
3977 *
3978 * Returns: determined end address within vmap_area
3979 */
3980static unsigned long
3981pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
3982{
3983 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3984 unsigned long addr;
3985
3986 if (likely(*va)) {
3987 list_for_each_entry_from_reverse((*va),
3988 &free_vmap_area_list, list) {
3989 addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
3990 if ((*va)->va_start < addr)
3991 return addr;
3992 }
3993 }
3994
3995 return 0;
3996}
3997
3998/**
3999 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
4000 * @offsets: array containing offset of each area
4001 * @sizes: array containing size of each area
4002 * @nr_vms: the number of areas to allocate
4003 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
4004 *
4005 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
4006 * vm_structs on success, %NULL on failure
4007 *
4008 * Percpu allocator wants to use congruent vm areas so that it can
4009 * maintain the offsets among percpu areas. This function allocates
4010 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
4011 * be scattered pretty far, distance between two areas easily going up
4012 * to gigabytes. To avoid interacting with regular vmallocs, these
4013 * areas are allocated from top.
4014 *
4015 * Despite its complicated look, this allocator is rather simple. It
4016 * does everything top-down and scans free blocks from the end looking
4017 * for matching base. While scanning, if any of the areas do not fit the
4018 * base address is pulled down to fit the area. Scanning is repeated till
4019 * all the areas fit and then all necessary data structures are inserted
4020 * and the result is returned.
4021 */
4022struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
4023 const size_t *sizes, int nr_vms,
4024 size_t align)
4025{
4026 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
4027 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
4028 struct vmap_area **vas, *va;
4029 struct vm_struct **vms;
4030 int area, area2, last_area, term_area;
4031 unsigned long base, start, size, end, last_end, orig_start, orig_end;
4032 bool purged = false;
4033
4034 /* verify parameters and allocate data structures */
4035 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
4036 for (last_area = 0, area = 0; area < nr_vms; area++) {
4037 start = offsets[area];
4038 end = start + sizes[area];
4039
4040 /* is everything aligned properly? */
4041 BUG_ON(!IS_ALIGNED(offsets[area], align));
4042 BUG_ON(!IS_ALIGNED(sizes[area], align));
4043
4044 /* detect the area with the highest address */
4045 if (start > offsets[last_area])
4046 last_area = area;
4047
4048 for (area2 = area + 1; area2 < nr_vms; area2++) {
4049 unsigned long start2 = offsets[area2];
4050 unsigned long end2 = start2 + sizes[area2];
4051
4052 BUG_ON(start2 < end && start < end2);
4053 }
4054 }
4055 last_end = offsets[last_area] + sizes[last_area];
4056
4057 if (vmalloc_end - vmalloc_start < last_end) {
4058 WARN_ON(true);
4059 return NULL;
4060 }
4061
4062 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
4063 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
4064 if (!vas || !vms)
4065 goto err_free2;
4066
4067 for (area = 0; area < nr_vms; area++) {
4068 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
4069 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
4070 if (!vas[area] || !vms[area])
4071 goto err_free;
4072 }
4073retry:
4074 spin_lock(&free_vmap_area_lock);
4075
4076 /* start scanning - we scan from the top, begin with the last area */
4077 area = term_area = last_area;
4078 start = offsets[area];
4079 end = start + sizes[area];
4080
4081 va = pvm_find_va_enclose_addr(vmalloc_end);
4082 base = pvm_determine_end_from_reverse(&va, align) - end;
4083
4084 while (true) {
4085 /*
4086 * base might have underflowed, add last_end before
4087 * comparing.
4088 */
4089 if (base + last_end < vmalloc_start + last_end)
4090 goto overflow;
4091
4092 /*
4093 * Fitting base has not been found.
4094 */
4095 if (va == NULL)
4096 goto overflow;
4097
4098 /*
4099 * If required width exceeds current VA block, move
4100 * base downwards and then recheck.
4101 */
4102 if (base + end > va->va_end) {
4103 base = pvm_determine_end_from_reverse(&va, align) - end;
4104 term_area = area;
4105 continue;
4106 }
4107
4108 /*
4109 * If this VA does not fit, move base downwards and recheck.
4110 */
4111 if (base + start < va->va_start) {
4112 va = node_to_va(rb_prev(&va->rb_node));
4113 base = pvm_determine_end_from_reverse(&va, align) - end;
4114 term_area = area;
4115 continue;
4116 }
4117
4118 /*
4119 * This area fits, move on to the previous one. If
4120 * the previous one is the terminal one, we're done.
4121 */
4122 area = (area + nr_vms - 1) % nr_vms;
4123 if (area == term_area)
4124 break;
4125
4126 start = offsets[area];
4127 end = start + sizes[area];
4128 va = pvm_find_va_enclose_addr(base + end);
4129 }
4130
4131 /* we've found a fitting base, insert all va's */
4132 for (area = 0; area < nr_vms; area++) {
4133 int ret;
4134
4135 start = base + offsets[area];
4136 size = sizes[area];
4137
4138 va = pvm_find_va_enclose_addr(start);
4139 if (WARN_ON_ONCE(va == NULL))
4140 /* It is a BUG(), but trigger recovery instead. */
4141 goto recovery;
4142
4143 ret = adjust_va_to_fit_type(&free_vmap_area_root,
4144 &free_vmap_area_list,
4145 va, start, size);
4146 if (WARN_ON_ONCE(unlikely(ret)))
4147 /* It is a BUG(), but trigger recovery instead. */
4148 goto recovery;
4149
4150 /* Allocated area. */
4151 va = vas[area];
4152 va->va_start = start;
4153 va->va_end = start + size;
4154 }
4155
4156 spin_unlock(&free_vmap_area_lock);
4157
4158 /* populate the kasan shadow space */
4159 for (area = 0; area < nr_vms; area++) {
4160 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area]))
4161 goto err_free_shadow;
4162 }
4163
4164 /* insert all vm's */
4165 spin_lock(&vmap_area_lock);
4166 for (area = 0; area < nr_vms; area++) {
4167 insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list);
4168
4169 setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
4170 pcpu_get_vm_areas);
4171 }
4172 spin_unlock(&vmap_area_lock);
4173
4174 /*
4175 * Mark allocated areas as accessible. Do it now as a best-effort
4176 * approach, as they can be mapped outside of vmalloc code.
4177 * With hardware tag-based KASAN, marking is skipped for
4178 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
4179 */
4180 for (area = 0; area < nr_vms; area++)
4181 vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr,
4182 vms[area]->size, KASAN_VMALLOC_PROT_NORMAL);
4183
4184 kfree(vas);
4185 return vms;
4186
4187recovery:
4188 /*
4189 * Remove previously allocated areas. There is no
4190 * need in removing these areas from the busy tree,
4191 * because they are inserted only on the final step
4192 * and when pcpu_get_vm_areas() is success.
4193 */
4194 while (area--) {
4195 orig_start = vas[area]->va_start;
4196 orig_end = vas[area]->va_end;
4197 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
4198 &free_vmap_area_list);
4199 if (va)
4200 kasan_release_vmalloc(orig_start, orig_end,
4201 va->va_start, va->va_end);
4202 vas[area] = NULL;
4203 }
4204
4205overflow:
4206 spin_unlock(&free_vmap_area_lock);
4207 if (!purged) {
4208 reclaim_and_purge_vmap_areas();
4209 purged = true;
4210
4211 /* Before "retry", check if we recover. */
4212 for (area = 0; area < nr_vms; area++) {
4213 if (vas[area])
4214 continue;
4215
4216 vas[area] = kmem_cache_zalloc(
4217 vmap_area_cachep, GFP_KERNEL);
4218 if (!vas[area])
4219 goto err_free;
4220 }
4221
4222 goto retry;
4223 }
4224
4225err_free:
4226 for (area = 0; area < nr_vms; area++) {
4227 if (vas[area])
4228 kmem_cache_free(vmap_area_cachep, vas[area]);
4229
4230 kfree(vms[area]);
4231 }
4232err_free2:
4233 kfree(vas);
4234 kfree(vms);
4235 return NULL;
4236
4237err_free_shadow:
4238 spin_lock(&free_vmap_area_lock);
4239 /*
4240 * We release all the vmalloc shadows, even the ones for regions that
4241 * hadn't been successfully added. This relies on kasan_release_vmalloc
4242 * being able to tolerate this case.
4243 */
4244 for (area = 0; area < nr_vms; area++) {
4245 orig_start = vas[area]->va_start;
4246 orig_end = vas[area]->va_end;
4247 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
4248 &free_vmap_area_list);
4249 if (va)
4250 kasan_release_vmalloc(orig_start, orig_end,
4251 va->va_start, va->va_end);
4252 vas[area] = NULL;
4253 kfree(vms[area]);
4254 }
4255 spin_unlock(&free_vmap_area_lock);
4256 kfree(vas);
4257 kfree(vms);
4258 return NULL;
4259}
4260
4261/**
4262 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
4263 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
4264 * @nr_vms: the number of allocated areas
4265 *
4266 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
4267 */
4268void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
4269{
4270 int i;
4271
4272 for (i = 0; i < nr_vms; i++)
4273 free_vm_area(vms[i]);
4274 kfree(vms);
4275}
4276#endif /* CONFIG_SMP */
4277
4278#ifdef CONFIG_PRINTK
4279bool vmalloc_dump_obj(void *object)
4280{
4281 void *objp = (void *)PAGE_ALIGN((unsigned long)object);
4282 const void *caller;
4283 struct vm_struct *vm;
4284 struct vmap_area *va;
4285 unsigned long addr;
4286 unsigned int nr_pages;
4287
4288 if (!spin_trylock(&vmap_area_lock))
4289 return false;
4290 va = __find_vmap_area((unsigned long)objp, &vmap_area_root);
4291 if (!va) {
4292 spin_unlock(&vmap_area_lock);
4293 return false;
4294 }
4295
4296 vm = va->vm;
4297 if (!vm) {
4298 spin_unlock(&vmap_area_lock);
4299 return false;
4300 }
4301 addr = (unsigned long)vm->addr;
4302 caller = vm->caller;
4303 nr_pages = vm->nr_pages;
4304 spin_unlock(&vmap_area_lock);
4305 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
4306 nr_pages, addr, caller);
4307 return true;
4308}
4309#endif
4310
4311#ifdef CONFIG_PROC_FS
4312static void *s_start(struct seq_file *m, loff_t *pos)
4313 __acquires(&vmap_purge_lock)
4314 __acquires(&vmap_area_lock)
4315{
4316 mutex_lock(&vmap_purge_lock);
4317 spin_lock(&vmap_area_lock);
4318
4319 return seq_list_start(&vmap_area_list, *pos);
4320}
4321
4322static void *s_next(struct seq_file *m, void *p, loff_t *pos)
4323{
4324 return seq_list_next(p, &vmap_area_list, pos);
4325}
4326
4327static void s_stop(struct seq_file *m, void *p)
4328 __releases(&vmap_area_lock)
4329 __releases(&vmap_purge_lock)
4330{
4331 spin_unlock(&vmap_area_lock);
4332 mutex_unlock(&vmap_purge_lock);
4333}
4334
4335static void show_numa_info(struct seq_file *m, struct vm_struct *v)
4336{
4337 if (IS_ENABLED(CONFIG_NUMA)) {
4338 unsigned int nr, *counters = m->private;
4339 unsigned int step = 1U << vm_area_page_order(v);
4340
4341 if (!counters)
4342 return;
4343
4344 if (v->flags & VM_UNINITIALIZED)
4345 return;
4346 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
4347 smp_rmb();
4348
4349 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
4350
4351 for (nr = 0; nr < v->nr_pages; nr += step)
4352 counters[page_to_nid(v->pages[nr])] += step;
4353 for_each_node_state(nr, N_HIGH_MEMORY)
4354 if (counters[nr])
4355 seq_printf(m, " N%u=%u", nr, counters[nr]);
4356 }
4357}
4358
4359static void show_purge_info(struct seq_file *m)
4360{
4361 struct vmap_area *va;
4362
4363 spin_lock(&purge_vmap_area_lock);
4364 list_for_each_entry(va, &purge_vmap_area_list, list) {
4365 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
4366 (void *)va->va_start, (void *)va->va_end,
4367 va->va_end - va->va_start);
4368 }
4369 spin_unlock(&purge_vmap_area_lock);
4370}
4371
4372static int s_show(struct seq_file *m, void *p)
4373{
4374 struct vmap_area *va;
4375 struct vm_struct *v;
4376
4377 va = list_entry(p, struct vmap_area, list);
4378
4379 if (!va->vm) {
4380 if (va->flags & VMAP_RAM)
4381 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
4382 (void *)va->va_start, (void *)va->va_end,
4383 va->va_end - va->va_start);
4384
4385 goto final;
4386 }
4387
4388 v = va->vm;
4389
4390 seq_printf(m, "0x%pK-0x%pK %7ld",
4391 v->addr, v->addr + v->size, v->size);
4392
4393 if (v->caller)
4394 seq_printf(m, " %pS", v->caller);
4395
4396 if (v->nr_pages)
4397 seq_printf(m, " pages=%d", v->nr_pages);
4398
4399 if (v->phys_addr)
4400 seq_printf(m, " phys=%pa", &v->phys_addr);
4401
4402 if (v->flags & VM_IOREMAP)
4403 seq_puts(m, " ioremap");
4404
4405 if (v->flags & VM_ALLOC)
4406 seq_puts(m, " vmalloc");
4407
4408 if (v->flags & VM_MAP)
4409 seq_puts(m, " vmap");
4410
4411 if (v->flags & VM_USERMAP)
4412 seq_puts(m, " user");
4413
4414 if (v->flags & VM_DMA_COHERENT)
4415 seq_puts(m, " dma-coherent");
4416
4417 if (is_vmalloc_addr(v->pages))
4418 seq_puts(m, " vpages");
4419
4420 show_numa_info(m, v);
4421 seq_putc(m, '\n');
4422
4423 /*
4424 * As a final step, dump "unpurged" areas.
4425 */
4426final:
4427 if (list_is_last(&va->list, &vmap_area_list))
4428 show_purge_info(m);
4429
4430 return 0;
4431}
4432
4433static const struct seq_operations vmalloc_op = {
4434 .start = s_start,
4435 .next = s_next,
4436 .stop = s_stop,
4437 .show = s_show,
4438};
4439
4440static int __init proc_vmalloc_init(void)
4441{
4442 if (IS_ENABLED(CONFIG_NUMA))
4443 proc_create_seq_private("vmallocinfo", 0400, NULL,
4444 &vmalloc_op,
4445 nr_node_ids * sizeof(unsigned int), NULL);
4446 else
4447 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
4448 return 0;
4449}
4450module_init(proc_vmalloc_init);
4451
4452#endif
4453
4454void __init vmalloc_init(void)
4455{
4456 struct vmap_area *va;
4457 struct vm_struct *tmp;
4458 int i;
4459
4460 /*
4461 * Create the cache for vmap_area objects.
4462 */
4463 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
4464
4465 for_each_possible_cpu(i) {
4466 struct vmap_block_queue *vbq;
4467 struct vfree_deferred *p;
4468
4469 vbq = &per_cpu(vmap_block_queue, i);
4470 spin_lock_init(&vbq->lock);
4471 INIT_LIST_HEAD(&vbq->free);
4472 p = &per_cpu(vfree_deferred, i);
4473 init_llist_head(&p->list);
4474 INIT_WORK(&p->wq, delayed_vfree_work);
4475 xa_init(&vbq->vmap_blocks);
4476 }
4477
4478 /* Import existing vmlist entries. */
4479 for (tmp = vmlist; tmp; tmp = tmp->next) {
4480 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
4481 if (WARN_ON_ONCE(!va))
4482 continue;
4483
4484 va->va_start = (unsigned long)tmp->addr;
4485 va->va_end = va->va_start + tmp->size;
4486 va->vm = tmp;
4487 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
4488 }
4489
4490 /*
4491 * Now we can initialize a free vmap space.
4492 */
4493 vmap_init_free_space();
4494 vmap_initialized = true;
4495}