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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/*
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.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/rbtree.h>
25#include <linux/radix-tree.h>
26#include <linux/rcupdate.h>
27#include <linux/pfn.h>
28#include <linux/kmemleak.h>
29#include <linux/atomic.h>
30#include <linux/compiler.h>
31#include <linux/llist.h>
32#include <linux/bitops.h>
33
34#include <asm/uaccess.h>
35#include <asm/tlbflush.h>
36#include <asm/shmparam.h>
37
38#include "internal.h"
39
40struct vfree_deferred {
41 struct llist_head list;
42 struct work_struct wq;
43};
44static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
45
46static void __vunmap(const void *, int);
47
48static void free_work(struct work_struct *w)
49{
50 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
51 struct llist_node *llnode = llist_del_all(&p->list);
52 while (llnode) {
53 void *p = llnode;
54 llnode = llist_next(llnode);
55 __vunmap(p, 1);
56 }
57}
58
59/*** Page table manipulation functions ***/
60
61static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
62{
63 pte_t *pte;
64
65 pte = pte_offset_kernel(pmd, addr);
66 do {
67 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
68 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
69 } while (pte++, addr += PAGE_SIZE, addr != end);
70}
71
72static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
73{
74 pmd_t *pmd;
75 unsigned long next;
76
77 pmd = pmd_offset(pud, addr);
78 do {
79 next = pmd_addr_end(addr, end);
80 if (pmd_clear_huge(pmd))
81 continue;
82 if (pmd_none_or_clear_bad(pmd))
83 continue;
84 vunmap_pte_range(pmd, addr, next);
85 } while (pmd++, addr = next, addr != end);
86}
87
88static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
89{
90 pud_t *pud;
91 unsigned long next;
92
93 pud = pud_offset(pgd, addr);
94 do {
95 next = pud_addr_end(addr, end);
96 if (pud_clear_huge(pud))
97 continue;
98 if (pud_none_or_clear_bad(pud))
99 continue;
100 vunmap_pmd_range(pud, addr, next);
101 } while (pud++, addr = next, addr != end);
102}
103
104static void vunmap_page_range(unsigned long addr, unsigned long end)
105{
106 pgd_t *pgd;
107 unsigned long next;
108
109 BUG_ON(addr >= end);
110 pgd = pgd_offset_k(addr);
111 do {
112 next = pgd_addr_end(addr, end);
113 if (pgd_none_or_clear_bad(pgd))
114 continue;
115 vunmap_pud_range(pgd, addr, next);
116 } while (pgd++, addr = next, addr != end);
117}
118
119static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
120 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
121{
122 pte_t *pte;
123
124 /*
125 * nr is a running index into the array which helps higher level
126 * callers keep track of where we're up to.
127 */
128
129 pte = pte_alloc_kernel(pmd, addr);
130 if (!pte)
131 return -ENOMEM;
132 do {
133 struct page *page = pages[*nr];
134
135 if (WARN_ON(!pte_none(*pte)))
136 return -EBUSY;
137 if (WARN_ON(!page))
138 return -ENOMEM;
139 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
140 (*nr)++;
141 } while (pte++, addr += PAGE_SIZE, addr != end);
142 return 0;
143}
144
145static int vmap_pmd_range(pud_t *pud, unsigned long addr,
146 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
147{
148 pmd_t *pmd;
149 unsigned long next;
150
151 pmd = pmd_alloc(&init_mm, pud, addr);
152 if (!pmd)
153 return -ENOMEM;
154 do {
155 next = pmd_addr_end(addr, end);
156 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
157 return -ENOMEM;
158 } while (pmd++, addr = next, addr != end);
159 return 0;
160}
161
162static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
163 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
164{
165 pud_t *pud;
166 unsigned long next;
167
168 pud = pud_alloc(&init_mm, pgd, addr);
169 if (!pud)
170 return -ENOMEM;
171 do {
172 next = pud_addr_end(addr, end);
173 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
174 return -ENOMEM;
175 } while (pud++, addr = next, addr != end);
176 return 0;
177}
178
179/*
180 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
181 * will have pfns corresponding to the "pages" array.
182 *
183 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
184 */
185static int vmap_page_range_noflush(unsigned long start, unsigned long end,
186 pgprot_t prot, struct page **pages)
187{
188 pgd_t *pgd;
189 unsigned long next;
190 unsigned long addr = start;
191 int err = 0;
192 int nr = 0;
193
194 BUG_ON(addr >= end);
195 pgd = pgd_offset_k(addr);
196 do {
197 next = pgd_addr_end(addr, end);
198 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
199 if (err)
200 return err;
201 } while (pgd++, addr = next, addr != end);
202
203 return nr;
204}
205
206static int vmap_page_range(unsigned long start, unsigned long end,
207 pgprot_t prot, struct page **pages)
208{
209 int ret;
210
211 ret = vmap_page_range_noflush(start, end, prot, pages);
212 flush_cache_vmap(start, end);
213 return ret;
214}
215
216int is_vmalloc_or_module_addr(const void *x)
217{
218 /*
219 * ARM, x86-64 and sparc64 put modules in a special place,
220 * and fall back on vmalloc() if that fails. Others
221 * just put it in the vmalloc space.
222 */
223#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
224 unsigned long addr = (unsigned long)x;
225 if (addr >= MODULES_VADDR && addr < MODULES_END)
226 return 1;
227#endif
228 return is_vmalloc_addr(x);
229}
230
231/*
232 * Walk a vmap address to the struct page it maps.
233 */
234struct page *vmalloc_to_page(const void *vmalloc_addr)
235{
236 unsigned long addr = (unsigned long) vmalloc_addr;
237 struct page *page = NULL;
238 pgd_t *pgd = pgd_offset_k(addr);
239
240 /*
241 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
242 * architectures that do not vmalloc module space
243 */
244 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
245
246 if (!pgd_none(*pgd)) {
247 pud_t *pud = pud_offset(pgd, addr);
248 if (!pud_none(*pud)) {
249 pmd_t *pmd = pmd_offset(pud, addr);
250 if (!pmd_none(*pmd)) {
251 pte_t *ptep, pte;
252
253 ptep = pte_offset_map(pmd, addr);
254 pte = *ptep;
255 if (pte_present(pte))
256 page = pte_page(pte);
257 pte_unmap(ptep);
258 }
259 }
260 }
261 return page;
262}
263EXPORT_SYMBOL(vmalloc_to_page);
264
265/*
266 * Map a vmalloc()-space virtual address to the physical page frame number.
267 */
268unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
269{
270 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
271}
272EXPORT_SYMBOL(vmalloc_to_pfn);
273
274
275/*** Global kva allocator ***/
276
277#define VM_LAZY_FREE 0x01
278#define VM_LAZY_FREEING 0x02
279#define VM_VM_AREA 0x04
280
281static DEFINE_SPINLOCK(vmap_area_lock);
282/* Export for kexec only */
283LIST_HEAD(vmap_area_list);
284static struct rb_root vmap_area_root = RB_ROOT;
285
286/* The vmap cache globals are protected by vmap_area_lock */
287static struct rb_node *free_vmap_cache;
288static unsigned long cached_hole_size;
289static unsigned long cached_vstart;
290static unsigned long cached_align;
291
292static unsigned long vmap_area_pcpu_hole;
293
294static struct vmap_area *__find_vmap_area(unsigned long addr)
295{
296 struct rb_node *n = vmap_area_root.rb_node;
297
298 while (n) {
299 struct vmap_area *va;
300
301 va = rb_entry(n, struct vmap_area, rb_node);
302 if (addr < va->va_start)
303 n = n->rb_left;
304 else if (addr >= va->va_end)
305 n = n->rb_right;
306 else
307 return va;
308 }
309
310 return NULL;
311}
312
313static void __insert_vmap_area(struct vmap_area *va)
314{
315 struct rb_node **p = &vmap_area_root.rb_node;
316 struct rb_node *parent = NULL;
317 struct rb_node *tmp;
318
319 while (*p) {
320 struct vmap_area *tmp_va;
321
322 parent = *p;
323 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
324 if (va->va_start < tmp_va->va_end)
325 p = &(*p)->rb_left;
326 else if (va->va_end > tmp_va->va_start)
327 p = &(*p)->rb_right;
328 else
329 BUG();
330 }
331
332 rb_link_node(&va->rb_node, parent, p);
333 rb_insert_color(&va->rb_node, &vmap_area_root);
334
335 /* address-sort this list */
336 tmp = rb_prev(&va->rb_node);
337 if (tmp) {
338 struct vmap_area *prev;
339 prev = rb_entry(tmp, struct vmap_area, rb_node);
340 list_add_rcu(&va->list, &prev->list);
341 } else
342 list_add_rcu(&va->list, &vmap_area_list);
343}
344
345static void purge_vmap_area_lazy(void);
346
347/*
348 * Allocate a region of KVA of the specified size and alignment, within the
349 * vstart and vend.
350 */
351static struct vmap_area *alloc_vmap_area(unsigned long size,
352 unsigned long align,
353 unsigned long vstart, unsigned long vend,
354 int node, gfp_t gfp_mask)
355{
356 struct vmap_area *va;
357 struct rb_node *n;
358 unsigned long addr;
359 int purged = 0;
360 struct vmap_area *first;
361
362 BUG_ON(!size);
363 BUG_ON(offset_in_page(size));
364 BUG_ON(!is_power_of_2(align));
365
366 va = kmalloc_node(sizeof(struct vmap_area),
367 gfp_mask & GFP_RECLAIM_MASK, node);
368 if (unlikely(!va))
369 return ERR_PTR(-ENOMEM);
370
371 /*
372 * Only scan the relevant parts containing pointers to other objects
373 * to avoid false negatives.
374 */
375 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);
376
377retry:
378 spin_lock(&vmap_area_lock);
379 /*
380 * Invalidate cache if we have more permissive parameters.
381 * cached_hole_size notes the largest hole noticed _below_
382 * the vmap_area cached in free_vmap_cache: if size fits
383 * into that hole, we want to scan from vstart to reuse
384 * the hole instead of allocating above free_vmap_cache.
385 * Note that __free_vmap_area may update free_vmap_cache
386 * without updating cached_hole_size or cached_align.
387 */
388 if (!free_vmap_cache ||
389 size < cached_hole_size ||
390 vstart < cached_vstart ||
391 align < cached_align) {
392nocache:
393 cached_hole_size = 0;
394 free_vmap_cache = NULL;
395 }
396 /* record if we encounter less permissive parameters */
397 cached_vstart = vstart;
398 cached_align = align;
399
400 /* find starting point for our search */
401 if (free_vmap_cache) {
402 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
403 addr = ALIGN(first->va_end, align);
404 if (addr < vstart)
405 goto nocache;
406 if (addr + size < addr)
407 goto overflow;
408
409 } else {
410 addr = ALIGN(vstart, align);
411 if (addr + size < addr)
412 goto overflow;
413
414 n = vmap_area_root.rb_node;
415 first = NULL;
416
417 while (n) {
418 struct vmap_area *tmp;
419 tmp = rb_entry(n, struct vmap_area, rb_node);
420 if (tmp->va_end >= addr) {
421 first = tmp;
422 if (tmp->va_start <= addr)
423 break;
424 n = n->rb_left;
425 } else
426 n = n->rb_right;
427 }
428
429 if (!first)
430 goto found;
431 }
432
433 /* from the starting point, walk areas until a suitable hole is found */
434 while (addr + size > first->va_start && addr + size <= vend) {
435 if (addr + cached_hole_size < first->va_start)
436 cached_hole_size = first->va_start - addr;
437 addr = ALIGN(first->va_end, align);
438 if (addr + size < addr)
439 goto overflow;
440
441 if (list_is_last(&first->list, &vmap_area_list))
442 goto found;
443
444 first = list_next_entry(first, list);
445 }
446
447found:
448 if (addr + size > vend)
449 goto overflow;
450
451 va->va_start = addr;
452 va->va_end = addr + size;
453 va->flags = 0;
454 __insert_vmap_area(va);
455 free_vmap_cache = &va->rb_node;
456 spin_unlock(&vmap_area_lock);
457
458 BUG_ON(!IS_ALIGNED(va->va_start, align));
459 BUG_ON(va->va_start < vstart);
460 BUG_ON(va->va_end > vend);
461
462 return va;
463
464overflow:
465 spin_unlock(&vmap_area_lock);
466 if (!purged) {
467 purge_vmap_area_lazy();
468 purged = 1;
469 goto retry;
470 }
471 if (printk_ratelimit())
472 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
473 size);
474 kfree(va);
475 return ERR_PTR(-EBUSY);
476}
477
478static void __free_vmap_area(struct vmap_area *va)
479{
480 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
481
482 if (free_vmap_cache) {
483 if (va->va_end < cached_vstart) {
484 free_vmap_cache = NULL;
485 } else {
486 struct vmap_area *cache;
487 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
488 if (va->va_start <= cache->va_start) {
489 free_vmap_cache = rb_prev(&va->rb_node);
490 /*
491 * We don't try to update cached_hole_size or
492 * cached_align, but it won't go very wrong.
493 */
494 }
495 }
496 }
497 rb_erase(&va->rb_node, &vmap_area_root);
498 RB_CLEAR_NODE(&va->rb_node);
499 list_del_rcu(&va->list);
500
501 /*
502 * Track the highest possible candidate for pcpu area
503 * allocation. Areas outside of vmalloc area can be returned
504 * here too, consider only end addresses which fall inside
505 * vmalloc area proper.
506 */
507 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
508 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
509
510 kfree_rcu(va, rcu_head);
511}
512
513/*
514 * Free a region of KVA allocated by alloc_vmap_area
515 */
516static void free_vmap_area(struct vmap_area *va)
517{
518 spin_lock(&vmap_area_lock);
519 __free_vmap_area(va);
520 spin_unlock(&vmap_area_lock);
521}
522
523/*
524 * Clear the pagetable entries of a given vmap_area
525 */
526static void unmap_vmap_area(struct vmap_area *va)
527{
528 vunmap_page_range(va->va_start, va->va_end);
529}
530
531static void vmap_debug_free_range(unsigned long start, unsigned long end)
532{
533 /*
534 * Unmap page tables and force a TLB flush immediately if pagealloc
535 * debugging is enabled. This catches use after free bugs similarly to
536 * those in linear kernel virtual address space after a page has been
537 * freed.
538 *
539 * All the lazy freeing logic is still retained, in order to minimise
540 * intrusiveness of this debugging feature.
541 *
542 * This is going to be *slow* (linear kernel virtual address debugging
543 * doesn't do a broadcast TLB flush so it is a lot faster).
544 */
545 if (debug_pagealloc_enabled()) {
546 vunmap_page_range(start, end);
547 flush_tlb_kernel_range(start, end);
548 }
549}
550
551/*
552 * lazy_max_pages is the maximum amount of virtual address space we gather up
553 * before attempting to purge with a TLB flush.
554 *
555 * There is a tradeoff here: a larger number will cover more kernel page tables
556 * and take slightly longer to purge, but it will linearly reduce the number of
557 * global TLB flushes that must be performed. It would seem natural to scale
558 * this number up linearly with the number of CPUs (because vmapping activity
559 * could also scale linearly with the number of CPUs), however it is likely
560 * that in practice, workloads might be constrained in other ways that mean
561 * vmap activity will not scale linearly with CPUs. Also, I want to be
562 * conservative and not introduce a big latency on huge systems, so go with
563 * a less aggressive log scale. It will still be an improvement over the old
564 * code, and it will be simple to change the scale factor if we find that it
565 * becomes a problem on bigger systems.
566 */
567static unsigned long lazy_max_pages(void)
568{
569 unsigned int log;
570
571 log = fls(num_online_cpus());
572
573 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
574}
575
576static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
577
578/* for per-CPU blocks */
579static void purge_fragmented_blocks_allcpus(void);
580
581/*
582 * called before a call to iounmap() if the caller wants vm_area_struct's
583 * immediately freed.
584 */
585void set_iounmap_nonlazy(void)
586{
587 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
588}
589
590/*
591 * Purges all lazily-freed vmap areas.
592 *
593 * If sync is 0 then don't purge if there is already a purge in progress.
594 * If force_flush is 1, then flush kernel TLBs between *start and *end even
595 * if we found no lazy vmap areas to unmap (callers can use this to optimise
596 * their own TLB flushing).
597 * Returns with *start = min(*start, lowest purged address)
598 * *end = max(*end, highest purged address)
599 */
600static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
601 int sync, int force_flush)
602{
603 static DEFINE_SPINLOCK(purge_lock);
604 LIST_HEAD(valist);
605 struct vmap_area *va;
606 struct vmap_area *n_va;
607 int nr = 0;
608
609 /*
610 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
611 * should not expect such behaviour. This just simplifies locking for
612 * the case that isn't actually used at the moment anyway.
613 */
614 if (!sync && !force_flush) {
615 if (!spin_trylock(&purge_lock))
616 return;
617 } else
618 spin_lock(&purge_lock);
619
620 if (sync)
621 purge_fragmented_blocks_allcpus();
622
623 rcu_read_lock();
624 list_for_each_entry_rcu(va, &vmap_area_list, list) {
625 if (va->flags & VM_LAZY_FREE) {
626 if (va->va_start < *start)
627 *start = va->va_start;
628 if (va->va_end > *end)
629 *end = va->va_end;
630 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
631 list_add_tail(&va->purge_list, &valist);
632 va->flags |= VM_LAZY_FREEING;
633 va->flags &= ~VM_LAZY_FREE;
634 }
635 }
636 rcu_read_unlock();
637
638 if (nr)
639 atomic_sub(nr, &vmap_lazy_nr);
640
641 if (nr || force_flush)
642 flush_tlb_kernel_range(*start, *end);
643
644 if (nr) {
645 spin_lock(&vmap_area_lock);
646 list_for_each_entry_safe(va, n_va, &valist, purge_list)
647 __free_vmap_area(va);
648 spin_unlock(&vmap_area_lock);
649 }
650 spin_unlock(&purge_lock);
651}
652
653/*
654 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
655 * is already purging.
656 */
657static void try_purge_vmap_area_lazy(void)
658{
659 unsigned long start = ULONG_MAX, end = 0;
660
661 __purge_vmap_area_lazy(&start, &end, 0, 0);
662}
663
664/*
665 * Kick off a purge of the outstanding lazy areas.
666 */
667static void purge_vmap_area_lazy(void)
668{
669 unsigned long start = ULONG_MAX, end = 0;
670
671 __purge_vmap_area_lazy(&start, &end, 1, 0);
672}
673
674/*
675 * Free a vmap area, caller ensuring that the area has been unmapped
676 * and flush_cache_vunmap had been called for the correct range
677 * previously.
678 */
679static void free_vmap_area_noflush(struct vmap_area *va)
680{
681 va->flags |= VM_LAZY_FREE;
682 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
683 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
684 try_purge_vmap_area_lazy();
685}
686
687/*
688 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
689 * called for the correct range previously.
690 */
691static void free_unmap_vmap_area_noflush(struct vmap_area *va)
692{
693 unmap_vmap_area(va);
694 free_vmap_area_noflush(va);
695}
696
697/*
698 * Free and unmap a vmap area
699 */
700static void free_unmap_vmap_area(struct vmap_area *va)
701{
702 flush_cache_vunmap(va->va_start, va->va_end);
703 free_unmap_vmap_area_noflush(va);
704}
705
706static struct vmap_area *find_vmap_area(unsigned long addr)
707{
708 struct vmap_area *va;
709
710 spin_lock(&vmap_area_lock);
711 va = __find_vmap_area(addr);
712 spin_unlock(&vmap_area_lock);
713
714 return va;
715}
716
717static void free_unmap_vmap_area_addr(unsigned long addr)
718{
719 struct vmap_area *va;
720
721 va = find_vmap_area(addr);
722 BUG_ON(!va);
723 free_unmap_vmap_area(va);
724}
725
726
727/*** Per cpu kva allocator ***/
728
729/*
730 * vmap space is limited especially on 32 bit architectures. Ensure there is
731 * room for at least 16 percpu vmap blocks per CPU.
732 */
733/*
734 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
735 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
736 * instead (we just need a rough idea)
737 */
738#if BITS_PER_LONG == 32
739#define VMALLOC_SPACE (128UL*1024*1024)
740#else
741#define VMALLOC_SPACE (128UL*1024*1024*1024)
742#endif
743
744#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
745#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
746#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
747#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
748#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
749#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
750#define VMAP_BBMAP_BITS \
751 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
752 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
753 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
754
755#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
756
757static bool vmap_initialized __read_mostly = false;
758
759struct vmap_block_queue {
760 spinlock_t lock;
761 struct list_head free;
762};
763
764struct vmap_block {
765 spinlock_t lock;
766 struct vmap_area *va;
767 unsigned long free, dirty;
768 unsigned long dirty_min, dirty_max; /*< dirty range */
769 struct list_head free_list;
770 struct rcu_head rcu_head;
771 struct list_head purge;
772};
773
774/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
775static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
776
777/*
778 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
779 * in the free path. Could get rid of this if we change the API to return a
780 * "cookie" from alloc, to be passed to free. But no big deal yet.
781 */
782static DEFINE_SPINLOCK(vmap_block_tree_lock);
783static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
784
785/*
786 * We should probably have a fallback mechanism to allocate virtual memory
787 * out of partially filled vmap blocks. However vmap block sizing should be
788 * fairly reasonable according to the vmalloc size, so it shouldn't be a
789 * big problem.
790 */
791
792static unsigned long addr_to_vb_idx(unsigned long addr)
793{
794 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
795 addr /= VMAP_BLOCK_SIZE;
796 return addr;
797}
798
799static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
800{
801 unsigned long addr;
802
803 addr = va_start + (pages_off << PAGE_SHIFT);
804 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
805 return (void *)addr;
806}
807
808/**
809 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
810 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
811 * @order: how many 2^order pages should be occupied in newly allocated block
812 * @gfp_mask: flags for the page level allocator
813 *
814 * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
815 */
816static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
817{
818 struct vmap_block_queue *vbq;
819 struct vmap_block *vb;
820 struct vmap_area *va;
821 unsigned long vb_idx;
822 int node, err;
823 void *vaddr;
824
825 node = numa_node_id();
826
827 vb = kmalloc_node(sizeof(struct vmap_block),
828 gfp_mask & GFP_RECLAIM_MASK, node);
829 if (unlikely(!vb))
830 return ERR_PTR(-ENOMEM);
831
832 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
833 VMALLOC_START, VMALLOC_END,
834 node, gfp_mask);
835 if (IS_ERR(va)) {
836 kfree(vb);
837 return ERR_CAST(va);
838 }
839
840 err = radix_tree_preload(gfp_mask);
841 if (unlikely(err)) {
842 kfree(vb);
843 free_vmap_area(va);
844 return ERR_PTR(err);
845 }
846
847 vaddr = vmap_block_vaddr(va->va_start, 0);
848 spin_lock_init(&vb->lock);
849 vb->va = va;
850 /* At least something should be left free */
851 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
852 vb->free = VMAP_BBMAP_BITS - (1UL << order);
853 vb->dirty = 0;
854 vb->dirty_min = VMAP_BBMAP_BITS;
855 vb->dirty_max = 0;
856 INIT_LIST_HEAD(&vb->free_list);
857
858 vb_idx = addr_to_vb_idx(va->va_start);
859 spin_lock(&vmap_block_tree_lock);
860 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
861 spin_unlock(&vmap_block_tree_lock);
862 BUG_ON(err);
863 radix_tree_preload_end();
864
865 vbq = &get_cpu_var(vmap_block_queue);
866 spin_lock(&vbq->lock);
867 list_add_tail_rcu(&vb->free_list, &vbq->free);
868 spin_unlock(&vbq->lock);
869 put_cpu_var(vmap_block_queue);
870
871 return vaddr;
872}
873
874static void free_vmap_block(struct vmap_block *vb)
875{
876 struct vmap_block *tmp;
877 unsigned long vb_idx;
878
879 vb_idx = addr_to_vb_idx(vb->va->va_start);
880 spin_lock(&vmap_block_tree_lock);
881 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
882 spin_unlock(&vmap_block_tree_lock);
883 BUG_ON(tmp != vb);
884
885 free_vmap_area_noflush(vb->va);
886 kfree_rcu(vb, rcu_head);
887}
888
889static void purge_fragmented_blocks(int cpu)
890{
891 LIST_HEAD(purge);
892 struct vmap_block *vb;
893 struct vmap_block *n_vb;
894 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
895
896 rcu_read_lock();
897 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
898
899 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
900 continue;
901
902 spin_lock(&vb->lock);
903 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
904 vb->free = 0; /* prevent further allocs after releasing lock */
905 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
906 vb->dirty_min = 0;
907 vb->dirty_max = VMAP_BBMAP_BITS;
908 spin_lock(&vbq->lock);
909 list_del_rcu(&vb->free_list);
910 spin_unlock(&vbq->lock);
911 spin_unlock(&vb->lock);
912 list_add_tail(&vb->purge, &purge);
913 } else
914 spin_unlock(&vb->lock);
915 }
916 rcu_read_unlock();
917
918 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
919 list_del(&vb->purge);
920 free_vmap_block(vb);
921 }
922}
923
924static void purge_fragmented_blocks_allcpus(void)
925{
926 int cpu;
927
928 for_each_possible_cpu(cpu)
929 purge_fragmented_blocks(cpu);
930}
931
932static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
933{
934 struct vmap_block_queue *vbq;
935 struct vmap_block *vb;
936 void *vaddr = NULL;
937 unsigned int order;
938
939 BUG_ON(offset_in_page(size));
940 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
941 if (WARN_ON(size == 0)) {
942 /*
943 * Allocating 0 bytes isn't what caller wants since
944 * get_order(0) returns funny result. Just warn and terminate
945 * early.
946 */
947 return NULL;
948 }
949 order = get_order(size);
950
951 rcu_read_lock();
952 vbq = &get_cpu_var(vmap_block_queue);
953 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
954 unsigned long pages_off;
955
956 spin_lock(&vb->lock);
957 if (vb->free < (1UL << order)) {
958 spin_unlock(&vb->lock);
959 continue;
960 }
961
962 pages_off = VMAP_BBMAP_BITS - vb->free;
963 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
964 vb->free -= 1UL << order;
965 if (vb->free == 0) {
966 spin_lock(&vbq->lock);
967 list_del_rcu(&vb->free_list);
968 spin_unlock(&vbq->lock);
969 }
970
971 spin_unlock(&vb->lock);
972 break;
973 }
974
975 put_cpu_var(vmap_block_queue);
976 rcu_read_unlock();
977
978 /* Allocate new block if nothing was found */
979 if (!vaddr)
980 vaddr = new_vmap_block(order, gfp_mask);
981
982 return vaddr;
983}
984
985static void vb_free(const void *addr, unsigned long size)
986{
987 unsigned long offset;
988 unsigned long vb_idx;
989 unsigned int order;
990 struct vmap_block *vb;
991
992 BUG_ON(offset_in_page(size));
993 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
994
995 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
996
997 order = get_order(size);
998
999 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
1000 offset >>= PAGE_SHIFT;
1001
1002 vb_idx = addr_to_vb_idx((unsigned long)addr);
1003 rcu_read_lock();
1004 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
1005 rcu_read_unlock();
1006 BUG_ON(!vb);
1007
1008 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
1009
1010 spin_lock(&vb->lock);
1011
1012 /* Expand dirty range */
1013 vb->dirty_min = min(vb->dirty_min, offset);
1014 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
1015
1016 vb->dirty += 1UL << order;
1017 if (vb->dirty == VMAP_BBMAP_BITS) {
1018 BUG_ON(vb->free);
1019 spin_unlock(&vb->lock);
1020 free_vmap_block(vb);
1021 } else
1022 spin_unlock(&vb->lock);
1023}
1024
1025/**
1026 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
1027 *
1028 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1029 * to amortize TLB flushing overheads. What this means is that any page you
1030 * have now, may, in a former life, have been mapped into kernel virtual
1031 * address by the vmap layer and so there might be some CPUs with TLB entries
1032 * still referencing that page (additional to the regular 1:1 kernel mapping).
1033 *
1034 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1035 * be sure that none of the pages we have control over will have any aliases
1036 * from the vmap layer.
1037 */
1038void vm_unmap_aliases(void)
1039{
1040 unsigned long start = ULONG_MAX, end = 0;
1041 int cpu;
1042 int flush = 0;
1043
1044 if (unlikely(!vmap_initialized))
1045 return;
1046
1047 for_each_possible_cpu(cpu) {
1048 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1049 struct vmap_block *vb;
1050
1051 rcu_read_lock();
1052 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1053 spin_lock(&vb->lock);
1054 if (vb->dirty) {
1055 unsigned long va_start = vb->va->va_start;
1056 unsigned long s, e;
1057
1058 s = va_start + (vb->dirty_min << PAGE_SHIFT);
1059 e = va_start + (vb->dirty_max << PAGE_SHIFT);
1060
1061 start = min(s, start);
1062 end = max(e, end);
1063
1064 flush = 1;
1065 }
1066 spin_unlock(&vb->lock);
1067 }
1068 rcu_read_unlock();
1069 }
1070
1071 __purge_vmap_area_lazy(&start, &end, 1, flush);
1072}
1073EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1074
1075/**
1076 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1077 * @mem: the pointer returned by vm_map_ram
1078 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1079 */
1080void vm_unmap_ram(const void *mem, unsigned int count)
1081{
1082 unsigned long size = count << PAGE_SHIFT;
1083 unsigned long addr = (unsigned long)mem;
1084
1085 BUG_ON(!addr);
1086 BUG_ON(addr < VMALLOC_START);
1087 BUG_ON(addr > VMALLOC_END);
1088 BUG_ON(!PAGE_ALIGNED(addr));
1089
1090 debug_check_no_locks_freed(mem, size);
1091 vmap_debug_free_range(addr, addr+size);
1092
1093 if (likely(count <= VMAP_MAX_ALLOC))
1094 vb_free(mem, size);
1095 else
1096 free_unmap_vmap_area_addr(addr);
1097}
1098EXPORT_SYMBOL(vm_unmap_ram);
1099
1100/**
1101 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1102 * @pages: an array of pointers to the pages to be mapped
1103 * @count: number of pages
1104 * @node: prefer to allocate data structures on this node
1105 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1106 *
1107 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
1108 * faster than vmap so it's good. But if you mix long-life and short-life
1109 * objects with vm_map_ram(), it could consume lots of address space through
1110 * fragmentation (especially on a 32bit machine). You could see failures in
1111 * the end. Please use this function for short-lived objects.
1112 *
1113 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1114 */
1115void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1116{
1117 unsigned long size = count << PAGE_SHIFT;
1118 unsigned long addr;
1119 void *mem;
1120
1121 if (likely(count <= VMAP_MAX_ALLOC)) {
1122 mem = vb_alloc(size, GFP_KERNEL);
1123 if (IS_ERR(mem))
1124 return NULL;
1125 addr = (unsigned long)mem;
1126 } else {
1127 struct vmap_area *va;
1128 va = alloc_vmap_area(size, PAGE_SIZE,
1129 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1130 if (IS_ERR(va))
1131 return NULL;
1132
1133 addr = va->va_start;
1134 mem = (void *)addr;
1135 }
1136 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1137 vm_unmap_ram(mem, count);
1138 return NULL;
1139 }
1140 return mem;
1141}
1142EXPORT_SYMBOL(vm_map_ram);
1143
1144static struct vm_struct *vmlist __initdata;
1145/**
1146 * vm_area_add_early - add vmap area early during boot
1147 * @vm: vm_struct to add
1148 *
1149 * This function is used to add fixed kernel vm area to vmlist before
1150 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
1151 * should contain proper values and the other fields should be zero.
1152 *
1153 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1154 */
1155void __init vm_area_add_early(struct vm_struct *vm)
1156{
1157 struct vm_struct *tmp, **p;
1158
1159 BUG_ON(vmap_initialized);
1160 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1161 if (tmp->addr >= vm->addr) {
1162 BUG_ON(tmp->addr < vm->addr + vm->size);
1163 break;
1164 } else
1165 BUG_ON(tmp->addr + tmp->size > vm->addr);
1166 }
1167 vm->next = *p;
1168 *p = vm;
1169}
1170
1171/**
1172 * vm_area_register_early - register vmap area early during boot
1173 * @vm: vm_struct to register
1174 * @align: requested alignment
1175 *
1176 * This function is used to register kernel vm area before
1177 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1178 * proper values on entry and other fields should be zero. On return,
1179 * vm->addr contains the allocated address.
1180 *
1181 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1182 */
1183void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1184{
1185 static size_t vm_init_off __initdata;
1186 unsigned long addr;
1187
1188 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1189 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1190
1191 vm->addr = (void *)addr;
1192
1193 vm_area_add_early(vm);
1194}
1195
1196void __init vmalloc_init(void)
1197{
1198 struct vmap_area *va;
1199 struct vm_struct *tmp;
1200 int i;
1201
1202 for_each_possible_cpu(i) {
1203 struct vmap_block_queue *vbq;
1204 struct vfree_deferred *p;
1205
1206 vbq = &per_cpu(vmap_block_queue, i);
1207 spin_lock_init(&vbq->lock);
1208 INIT_LIST_HEAD(&vbq->free);
1209 p = &per_cpu(vfree_deferred, i);
1210 init_llist_head(&p->list);
1211 INIT_WORK(&p->wq, free_work);
1212 }
1213
1214 /* Import existing vmlist entries. */
1215 for (tmp = vmlist; tmp; tmp = tmp->next) {
1216 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1217 va->flags = VM_VM_AREA;
1218 va->va_start = (unsigned long)tmp->addr;
1219 va->va_end = va->va_start + tmp->size;
1220 va->vm = tmp;
1221 __insert_vmap_area(va);
1222 }
1223
1224 vmap_area_pcpu_hole = VMALLOC_END;
1225
1226 vmap_initialized = true;
1227}
1228
1229/**
1230 * map_kernel_range_noflush - map kernel VM area with the specified pages
1231 * @addr: start of the VM area to map
1232 * @size: size of the VM area to map
1233 * @prot: page protection flags to use
1234 * @pages: pages to map
1235 *
1236 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1237 * specify should have been allocated using get_vm_area() and its
1238 * friends.
1239 *
1240 * NOTE:
1241 * This function does NOT do any cache flushing. The caller is
1242 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1243 * before calling this function.
1244 *
1245 * RETURNS:
1246 * The number of pages mapped on success, -errno on failure.
1247 */
1248int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1249 pgprot_t prot, struct page **pages)
1250{
1251 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1252}
1253
1254/**
1255 * unmap_kernel_range_noflush - unmap kernel VM area
1256 * @addr: start of the VM area to unmap
1257 * @size: size of the VM area to unmap
1258 *
1259 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1260 * specify should have been allocated using get_vm_area() and its
1261 * friends.
1262 *
1263 * NOTE:
1264 * This function does NOT do any cache flushing. The caller is
1265 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1266 * before calling this function and flush_tlb_kernel_range() after.
1267 */
1268void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1269{
1270 vunmap_page_range(addr, addr + size);
1271}
1272EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1273
1274/**
1275 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1276 * @addr: start of the VM area to unmap
1277 * @size: size of the VM area to unmap
1278 *
1279 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1280 * the unmapping and tlb after.
1281 */
1282void unmap_kernel_range(unsigned long addr, unsigned long size)
1283{
1284 unsigned long end = addr + size;
1285
1286 flush_cache_vunmap(addr, end);
1287 vunmap_page_range(addr, end);
1288 flush_tlb_kernel_range(addr, end);
1289}
1290EXPORT_SYMBOL_GPL(unmap_kernel_range);
1291
1292int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages)
1293{
1294 unsigned long addr = (unsigned long)area->addr;
1295 unsigned long end = addr + get_vm_area_size(area);
1296 int err;
1297
1298 err = vmap_page_range(addr, end, prot, pages);
1299
1300 return err > 0 ? 0 : err;
1301}
1302EXPORT_SYMBOL_GPL(map_vm_area);
1303
1304static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1305 unsigned long flags, const void *caller)
1306{
1307 spin_lock(&vmap_area_lock);
1308 vm->flags = flags;
1309 vm->addr = (void *)va->va_start;
1310 vm->size = va->va_end - va->va_start;
1311 vm->caller = caller;
1312 va->vm = vm;
1313 va->flags |= VM_VM_AREA;
1314 spin_unlock(&vmap_area_lock);
1315}
1316
1317static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1318{
1319 /*
1320 * Before removing VM_UNINITIALIZED,
1321 * we should make sure that vm has proper values.
1322 * Pair with smp_rmb() in show_numa_info().
1323 */
1324 smp_wmb();
1325 vm->flags &= ~VM_UNINITIALIZED;
1326}
1327
1328static struct vm_struct *__get_vm_area_node(unsigned long size,
1329 unsigned long align, unsigned long flags, unsigned long start,
1330 unsigned long end, int node, gfp_t gfp_mask, const void *caller)
1331{
1332 struct vmap_area *va;
1333 struct vm_struct *area;
1334
1335 BUG_ON(in_interrupt());
1336 if (flags & VM_IOREMAP)
1337 align = 1ul << clamp_t(int, fls_long(size),
1338 PAGE_SHIFT, IOREMAP_MAX_ORDER);
1339
1340 size = PAGE_ALIGN(size);
1341 if (unlikely(!size))
1342 return NULL;
1343
1344 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1345 if (unlikely(!area))
1346 return NULL;
1347
1348 if (!(flags & VM_NO_GUARD))
1349 size += PAGE_SIZE;
1350
1351 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1352 if (IS_ERR(va)) {
1353 kfree(area);
1354 return NULL;
1355 }
1356
1357 setup_vmalloc_vm(area, va, flags, caller);
1358
1359 return area;
1360}
1361
1362struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1363 unsigned long start, unsigned long end)
1364{
1365 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1366 GFP_KERNEL, __builtin_return_address(0));
1367}
1368EXPORT_SYMBOL_GPL(__get_vm_area);
1369
1370struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1371 unsigned long start, unsigned long end,
1372 const void *caller)
1373{
1374 return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE,
1375 GFP_KERNEL, caller);
1376}
1377
1378/**
1379 * get_vm_area - reserve a contiguous kernel virtual area
1380 * @size: size of the area
1381 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1382 *
1383 * Search an area of @size in the kernel virtual mapping area,
1384 * and reserved it for out purposes. Returns the area descriptor
1385 * on success or %NULL on failure.
1386 */
1387struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1388{
1389 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1390 NUMA_NO_NODE, GFP_KERNEL,
1391 __builtin_return_address(0));
1392}
1393
1394struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1395 const void *caller)
1396{
1397 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1398 NUMA_NO_NODE, GFP_KERNEL, caller);
1399}
1400
1401/**
1402 * find_vm_area - find a continuous kernel virtual area
1403 * @addr: base address
1404 *
1405 * Search for the kernel VM area starting at @addr, and return it.
1406 * It is up to the caller to do all required locking to keep the returned
1407 * pointer valid.
1408 */
1409struct vm_struct *find_vm_area(const void *addr)
1410{
1411 struct vmap_area *va;
1412
1413 va = find_vmap_area((unsigned long)addr);
1414 if (va && va->flags & VM_VM_AREA)
1415 return va->vm;
1416
1417 return NULL;
1418}
1419
1420/**
1421 * remove_vm_area - find and remove a continuous kernel virtual area
1422 * @addr: base address
1423 *
1424 * Search for the kernel VM area starting at @addr, and remove it.
1425 * This function returns the found VM area, but using it is NOT safe
1426 * on SMP machines, except for its size or flags.
1427 */
1428struct vm_struct *remove_vm_area(const void *addr)
1429{
1430 struct vmap_area *va;
1431
1432 va = find_vmap_area((unsigned long)addr);
1433 if (va && va->flags & VM_VM_AREA) {
1434 struct vm_struct *vm = va->vm;
1435
1436 spin_lock(&vmap_area_lock);
1437 va->vm = NULL;
1438 va->flags &= ~VM_VM_AREA;
1439 spin_unlock(&vmap_area_lock);
1440
1441 vmap_debug_free_range(va->va_start, va->va_end);
1442 kasan_free_shadow(vm);
1443 free_unmap_vmap_area(va);
1444
1445 return vm;
1446 }
1447 return NULL;
1448}
1449
1450static void __vunmap(const void *addr, int deallocate_pages)
1451{
1452 struct vm_struct *area;
1453
1454 if (!addr)
1455 return;
1456
1457 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
1458 addr))
1459 return;
1460
1461 area = remove_vm_area(addr);
1462 if (unlikely(!area)) {
1463 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1464 addr);
1465 return;
1466 }
1467
1468 debug_check_no_locks_freed(addr, get_vm_area_size(area));
1469 debug_check_no_obj_freed(addr, get_vm_area_size(area));
1470
1471 if (deallocate_pages) {
1472 int i;
1473
1474 for (i = 0; i < area->nr_pages; i++) {
1475 struct page *page = area->pages[i];
1476
1477 BUG_ON(!page);
1478 __free_kmem_pages(page, 0);
1479 }
1480
1481 kvfree(area->pages);
1482 }
1483
1484 kfree(area);
1485 return;
1486}
1487
1488/**
1489 * vfree - release memory allocated by vmalloc()
1490 * @addr: memory base address
1491 *
1492 * Free the virtually continuous memory area starting at @addr, as
1493 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1494 * NULL, no operation is performed.
1495 *
1496 * Must not be called in NMI context (strictly speaking, only if we don't
1497 * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
1498 * conventions for vfree() arch-depenedent would be a really bad idea)
1499 *
1500 * NOTE: assumes that the object at *addr has a size >= sizeof(llist_node)
1501 */
1502void vfree(const void *addr)
1503{
1504 BUG_ON(in_nmi());
1505
1506 kmemleak_free(addr);
1507
1508 if (!addr)
1509 return;
1510 if (unlikely(in_interrupt())) {
1511 struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
1512 if (llist_add((struct llist_node *)addr, &p->list))
1513 schedule_work(&p->wq);
1514 } else
1515 __vunmap(addr, 1);
1516}
1517EXPORT_SYMBOL(vfree);
1518
1519/**
1520 * vunmap - release virtual mapping obtained by vmap()
1521 * @addr: memory base address
1522 *
1523 * Free the virtually contiguous memory area starting at @addr,
1524 * which was created from the page array passed to vmap().
1525 *
1526 * Must not be called in interrupt context.
1527 */
1528void vunmap(const void *addr)
1529{
1530 BUG_ON(in_interrupt());
1531 might_sleep();
1532 if (addr)
1533 __vunmap(addr, 0);
1534}
1535EXPORT_SYMBOL(vunmap);
1536
1537/**
1538 * vmap - map an array of pages into virtually contiguous space
1539 * @pages: array of page pointers
1540 * @count: number of pages to map
1541 * @flags: vm_area->flags
1542 * @prot: page protection for the mapping
1543 *
1544 * Maps @count pages from @pages into contiguous kernel virtual
1545 * space.
1546 */
1547void *vmap(struct page **pages, unsigned int count,
1548 unsigned long flags, pgprot_t prot)
1549{
1550 struct vm_struct *area;
1551
1552 might_sleep();
1553
1554 if (count > totalram_pages)
1555 return NULL;
1556
1557 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1558 __builtin_return_address(0));
1559 if (!area)
1560 return NULL;
1561
1562 if (map_vm_area(area, prot, pages)) {
1563 vunmap(area->addr);
1564 return NULL;
1565 }
1566
1567 return area->addr;
1568}
1569EXPORT_SYMBOL(vmap);
1570
1571static void *__vmalloc_node(unsigned long size, unsigned long align,
1572 gfp_t gfp_mask, pgprot_t prot,
1573 int node, const void *caller);
1574static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1575 pgprot_t prot, int node)
1576{
1577 const int order = 0;
1578 struct page **pages;
1579 unsigned int nr_pages, array_size, i;
1580 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1581 const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
1582
1583 nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
1584 array_size = (nr_pages * sizeof(struct page *));
1585
1586 area->nr_pages = nr_pages;
1587 /* Please note that the recursion is strictly bounded. */
1588 if (array_size > PAGE_SIZE) {
1589 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1590 PAGE_KERNEL, node, area->caller);
1591 } else {
1592 pages = kmalloc_node(array_size, nested_gfp, node);
1593 }
1594 area->pages = pages;
1595 if (!area->pages) {
1596 remove_vm_area(area->addr);
1597 kfree(area);
1598 return NULL;
1599 }
1600
1601 for (i = 0; i < area->nr_pages; i++) {
1602 struct page *page;
1603
1604 if (node == NUMA_NO_NODE)
1605 page = alloc_kmem_pages(alloc_mask, order);
1606 else
1607 page = alloc_kmem_pages_node(node, alloc_mask, order);
1608
1609 if (unlikely(!page)) {
1610 /* Successfully allocated i pages, free them in __vunmap() */
1611 area->nr_pages = i;
1612 goto fail;
1613 }
1614 area->pages[i] = page;
1615 if (gfpflags_allow_blocking(gfp_mask))
1616 cond_resched();
1617 }
1618
1619 if (map_vm_area(area, prot, pages))
1620 goto fail;
1621 return area->addr;
1622
1623fail:
1624 warn_alloc_failed(gfp_mask, order,
1625 "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1626 (area->nr_pages*PAGE_SIZE), area->size);
1627 vfree(area->addr);
1628 return NULL;
1629}
1630
1631/**
1632 * __vmalloc_node_range - allocate virtually contiguous memory
1633 * @size: allocation size
1634 * @align: desired alignment
1635 * @start: vm area range start
1636 * @end: vm area range end
1637 * @gfp_mask: flags for the page level allocator
1638 * @prot: protection mask for the allocated pages
1639 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
1640 * @node: node to use for allocation or NUMA_NO_NODE
1641 * @caller: caller's return address
1642 *
1643 * Allocate enough pages to cover @size from the page level
1644 * allocator with @gfp_mask flags. Map them into contiguous
1645 * kernel virtual space, using a pagetable protection of @prot.
1646 */
1647void *__vmalloc_node_range(unsigned long size, unsigned long align,
1648 unsigned long start, unsigned long end, gfp_t gfp_mask,
1649 pgprot_t prot, unsigned long vm_flags, int node,
1650 const void *caller)
1651{
1652 struct vm_struct *area;
1653 void *addr;
1654 unsigned long real_size = size;
1655
1656 size = PAGE_ALIGN(size);
1657 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1658 goto fail;
1659
1660 area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
1661 vm_flags, start, end, node, gfp_mask, caller);
1662 if (!area)
1663 goto fail;
1664
1665 addr = __vmalloc_area_node(area, gfp_mask, prot, node);
1666 if (!addr)
1667 return NULL;
1668
1669 /*
1670 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
1671 * flag. It means that vm_struct is not fully initialized.
1672 * Now, it is fully initialized, so remove this flag here.
1673 */
1674 clear_vm_uninitialized_flag(area);
1675
1676 /*
1677 * A ref_count = 2 is needed because vm_struct allocated in
1678 * __get_vm_area_node() contains a reference to the virtual address of
1679 * the vmalloc'ed block.
1680 */
1681 kmemleak_alloc(addr, real_size, 2, gfp_mask);
1682
1683 return addr;
1684
1685fail:
1686 warn_alloc_failed(gfp_mask, 0,
1687 "vmalloc: allocation failure: %lu bytes\n",
1688 real_size);
1689 return NULL;
1690}
1691
1692/**
1693 * __vmalloc_node - allocate virtually contiguous memory
1694 * @size: allocation size
1695 * @align: desired alignment
1696 * @gfp_mask: flags for the page level allocator
1697 * @prot: protection mask for the allocated pages
1698 * @node: node to use for allocation or NUMA_NO_NODE
1699 * @caller: caller's return address
1700 *
1701 * Allocate enough pages to cover @size from the page level
1702 * allocator with @gfp_mask flags. Map them into contiguous
1703 * kernel virtual space, using a pagetable protection of @prot.
1704 */
1705static void *__vmalloc_node(unsigned long size, unsigned long align,
1706 gfp_t gfp_mask, pgprot_t prot,
1707 int node, const void *caller)
1708{
1709 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1710 gfp_mask, prot, 0, node, caller);
1711}
1712
1713void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1714{
1715 return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE,
1716 __builtin_return_address(0));
1717}
1718EXPORT_SYMBOL(__vmalloc);
1719
1720static inline void *__vmalloc_node_flags(unsigned long size,
1721 int node, gfp_t flags)
1722{
1723 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1724 node, __builtin_return_address(0));
1725}
1726
1727/**
1728 * vmalloc - allocate virtually contiguous memory
1729 * @size: allocation size
1730 * Allocate enough pages to cover @size from the page level
1731 * allocator and map them into contiguous kernel virtual space.
1732 *
1733 * For tight control over page level allocator and protection flags
1734 * use __vmalloc() instead.
1735 */
1736void *vmalloc(unsigned long size)
1737{
1738 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1739 GFP_KERNEL | __GFP_HIGHMEM);
1740}
1741EXPORT_SYMBOL(vmalloc);
1742
1743/**
1744 * vzalloc - allocate virtually contiguous memory with zero fill
1745 * @size: allocation size
1746 * Allocate enough pages to cover @size from the page level
1747 * allocator and map them into contiguous kernel virtual space.
1748 * The memory allocated is set to zero.
1749 *
1750 * For tight control over page level allocator and protection flags
1751 * use __vmalloc() instead.
1752 */
1753void *vzalloc(unsigned long size)
1754{
1755 return __vmalloc_node_flags(size, NUMA_NO_NODE,
1756 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1757}
1758EXPORT_SYMBOL(vzalloc);
1759
1760/**
1761 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1762 * @size: allocation size
1763 *
1764 * The resulting memory area is zeroed so it can be mapped to userspace
1765 * without leaking data.
1766 */
1767void *vmalloc_user(unsigned long size)
1768{
1769 struct vm_struct *area;
1770 void *ret;
1771
1772 ret = __vmalloc_node(size, SHMLBA,
1773 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1774 PAGE_KERNEL, NUMA_NO_NODE,
1775 __builtin_return_address(0));
1776 if (ret) {
1777 area = find_vm_area(ret);
1778 area->flags |= VM_USERMAP;
1779 }
1780 return ret;
1781}
1782EXPORT_SYMBOL(vmalloc_user);
1783
1784/**
1785 * vmalloc_node - allocate memory on a specific node
1786 * @size: allocation size
1787 * @node: numa node
1788 *
1789 * Allocate enough pages to cover @size from the page level
1790 * allocator and map them into contiguous kernel virtual space.
1791 *
1792 * For tight control over page level allocator and protection flags
1793 * use __vmalloc() instead.
1794 */
1795void *vmalloc_node(unsigned long size, int node)
1796{
1797 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1798 node, __builtin_return_address(0));
1799}
1800EXPORT_SYMBOL(vmalloc_node);
1801
1802/**
1803 * vzalloc_node - allocate memory on a specific node with zero fill
1804 * @size: allocation size
1805 * @node: numa node
1806 *
1807 * Allocate enough pages to cover @size from the page level
1808 * allocator and map them into contiguous kernel virtual space.
1809 * The memory allocated is set to zero.
1810 *
1811 * For tight control over page level allocator and protection flags
1812 * use __vmalloc_node() instead.
1813 */
1814void *vzalloc_node(unsigned long size, int node)
1815{
1816 return __vmalloc_node_flags(size, node,
1817 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1818}
1819EXPORT_SYMBOL(vzalloc_node);
1820
1821#ifndef PAGE_KERNEL_EXEC
1822# define PAGE_KERNEL_EXEC PAGE_KERNEL
1823#endif
1824
1825/**
1826 * vmalloc_exec - allocate virtually contiguous, executable memory
1827 * @size: allocation size
1828 *
1829 * Kernel-internal function to allocate enough pages to cover @size
1830 * the page level allocator and map them into contiguous and
1831 * executable kernel virtual space.
1832 *
1833 * For tight control over page level allocator and protection flags
1834 * use __vmalloc() instead.
1835 */
1836
1837void *vmalloc_exec(unsigned long size)
1838{
1839 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1840 NUMA_NO_NODE, __builtin_return_address(0));
1841}
1842
1843#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1844#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1845#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1846#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1847#else
1848#define GFP_VMALLOC32 GFP_KERNEL
1849#endif
1850
1851/**
1852 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1853 * @size: allocation size
1854 *
1855 * Allocate enough 32bit PA addressable pages to cover @size from the
1856 * page level allocator and map them into contiguous kernel virtual space.
1857 */
1858void *vmalloc_32(unsigned long size)
1859{
1860 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1861 NUMA_NO_NODE, __builtin_return_address(0));
1862}
1863EXPORT_SYMBOL(vmalloc_32);
1864
1865/**
1866 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1867 * @size: allocation size
1868 *
1869 * The resulting memory area is 32bit addressable and zeroed so it can be
1870 * mapped to userspace without leaking data.
1871 */
1872void *vmalloc_32_user(unsigned long size)
1873{
1874 struct vm_struct *area;
1875 void *ret;
1876
1877 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1878 NUMA_NO_NODE, __builtin_return_address(0));
1879 if (ret) {
1880 area = find_vm_area(ret);
1881 area->flags |= VM_USERMAP;
1882 }
1883 return ret;
1884}
1885EXPORT_SYMBOL(vmalloc_32_user);
1886
1887/*
1888 * small helper routine , copy contents to buf from addr.
1889 * If the page is not present, fill zero.
1890 */
1891
1892static int aligned_vread(char *buf, char *addr, unsigned long count)
1893{
1894 struct page *p;
1895 int copied = 0;
1896
1897 while (count) {
1898 unsigned long offset, length;
1899
1900 offset = offset_in_page(addr);
1901 length = PAGE_SIZE - offset;
1902 if (length > count)
1903 length = count;
1904 p = vmalloc_to_page(addr);
1905 /*
1906 * To do safe access to this _mapped_ area, we need
1907 * lock. But adding lock here means that we need to add
1908 * overhead of vmalloc()/vfree() calles for this _debug_
1909 * interface, rarely used. Instead of that, we'll use
1910 * kmap() and get small overhead in this access function.
1911 */
1912 if (p) {
1913 /*
1914 * we can expect USER0 is not used (see vread/vwrite's
1915 * function description)
1916 */
1917 void *map = kmap_atomic(p);
1918 memcpy(buf, map + offset, length);
1919 kunmap_atomic(map);
1920 } else
1921 memset(buf, 0, length);
1922
1923 addr += length;
1924 buf += length;
1925 copied += length;
1926 count -= length;
1927 }
1928 return copied;
1929}
1930
1931static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1932{
1933 struct page *p;
1934 int copied = 0;
1935
1936 while (count) {
1937 unsigned long offset, length;
1938
1939 offset = offset_in_page(addr);
1940 length = PAGE_SIZE - offset;
1941 if (length > count)
1942 length = count;
1943 p = vmalloc_to_page(addr);
1944 /*
1945 * To do safe access to this _mapped_ area, we need
1946 * lock. But adding lock here means that we need to add
1947 * overhead of vmalloc()/vfree() calles for this _debug_
1948 * interface, rarely used. Instead of that, we'll use
1949 * kmap() and get small overhead in this access function.
1950 */
1951 if (p) {
1952 /*
1953 * we can expect USER0 is not used (see vread/vwrite's
1954 * function description)
1955 */
1956 void *map = kmap_atomic(p);
1957 memcpy(map + offset, buf, length);
1958 kunmap_atomic(map);
1959 }
1960 addr += length;
1961 buf += length;
1962 copied += length;
1963 count -= length;
1964 }
1965 return copied;
1966}
1967
1968/**
1969 * vread() - read vmalloc area in a safe way.
1970 * @buf: buffer for reading data
1971 * @addr: vm address.
1972 * @count: number of bytes to be read.
1973 *
1974 * Returns # of bytes which addr and buf should be increased.
1975 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1976 * includes any intersect with alive vmalloc area.
1977 *
1978 * This function checks that addr is a valid vmalloc'ed area, and
1979 * copy data from that area to a given buffer. If the given memory range
1980 * of [addr...addr+count) includes some valid address, data is copied to
1981 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1982 * IOREMAP area is treated as memory hole and no copy is done.
1983 *
1984 * If [addr...addr+count) doesn't includes any intersects with alive
1985 * vm_struct area, returns 0. @buf should be kernel's buffer.
1986 *
1987 * Note: In usual ops, vread() is never necessary because the caller
1988 * should know vmalloc() area is valid and can use memcpy().
1989 * This is for routines which have to access vmalloc area without
1990 * any informaion, as /dev/kmem.
1991 *
1992 */
1993
1994long vread(char *buf, char *addr, unsigned long count)
1995{
1996 struct vmap_area *va;
1997 struct vm_struct *vm;
1998 char *vaddr, *buf_start = buf;
1999 unsigned long buflen = count;
2000 unsigned long n;
2001
2002 /* Don't allow overflow */
2003 if ((unsigned long) addr + count < count)
2004 count = -(unsigned long) addr;
2005
2006 spin_lock(&vmap_area_lock);
2007 list_for_each_entry(va, &vmap_area_list, list) {
2008 if (!count)
2009 break;
2010
2011 if (!(va->flags & VM_VM_AREA))
2012 continue;
2013
2014 vm = va->vm;
2015 vaddr = (char *) vm->addr;
2016 if (addr >= vaddr + get_vm_area_size(vm))
2017 continue;
2018 while (addr < vaddr) {
2019 if (count == 0)
2020 goto finished;
2021 *buf = '\0';
2022 buf++;
2023 addr++;
2024 count--;
2025 }
2026 n = vaddr + get_vm_area_size(vm) - addr;
2027 if (n > count)
2028 n = count;
2029 if (!(vm->flags & VM_IOREMAP))
2030 aligned_vread(buf, addr, n);
2031 else /* IOREMAP area is treated as memory hole */
2032 memset(buf, 0, n);
2033 buf += n;
2034 addr += n;
2035 count -= n;
2036 }
2037finished:
2038 spin_unlock(&vmap_area_lock);
2039
2040 if (buf == buf_start)
2041 return 0;
2042 /* zero-fill memory holes */
2043 if (buf != buf_start + buflen)
2044 memset(buf, 0, buflen - (buf - buf_start));
2045
2046 return buflen;
2047}
2048
2049/**
2050 * vwrite() - write vmalloc area in a safe way.
2051 * @buf: buffer for source data
2052 * @addr: vm address.
2053 * @count: number of bytes to be read.
2054 *
2055 * Returns # of bytes which addr and buf should be incresed.
2056 * (same number to @count).
2057 * If [addr...addr+count) doesn't includes any intersect with valid
2058 * vmalloc area, returns 0.
2059 *
2060 * This function checks that addr is a valid vmalloc'ed area, and
2061 * copy data from a buffer to the given addr. If specified range of
2062 * [addr...addr+count) includes some valid address, data is copied from
2063 * proper area of @buf. If there are memory holes, no copy to hole.
2064 * IOREMAP area is treated as memory hole and no copy is done.
2065 *
2066 * If [addr...addr+count) doesn't includes any intersects with alive
2067 * vm_struct area, returns 0. @buf should be kernel's buffer.
2068 *
2069 * Note: In usual ops, vwrite() is never necessary because the caller
2070 * should know vmalloc() area is valid and can use memcpy().
2071 * This is for routines which have to access vmalloc area without
2072 * any informaion, as /dev/kmem.
2073 */
2074
2075long vwrite(char *buf, char *addr, unsigned long count)
2076{
2077 struct vmap_area *va;
2078 struct vm_struct *vm;
2079 char *vaddr;
2080 unsigned long n, buflen;
2081 int copied = 0;
2082
2083 /* Don't allow overflow */
2084 if ((unsigned long) addr + count < count)
2085 count = -(unsigned long) addr;
2086 buflen = count;
2087
2088 spin_lock(&vmap_area_lock);
2089 list_for_each_entry(va, &vmap_area_list, list) {
2090 if (!count)
2091 break;
2092
2093 if (!(va->flags & VM_VM_AREA))
2094 continue;
2095
2096 vm = va->vm;
2097 vaddr = (char *) vm->addr;
2098 if (addr >= vaddr + get_vm_area_size(vm))
2099 continue;
2100 while (addr < vaddr) {
2101 if (count == 0)
2102 goto finished;
2103 buf++;
2104 addr++;
2105 count--;
2106 }
2107 n = vaddr + get_vm_area_size(vm) - addr;
2108 if (n > count)
2109 n = count;
2110 if (!(vm->flags & VM_IOREMAP)) {
2111 aligned_vwrite(buf, addr, n);
2112 copied++;
2113 }
2114 buf += n;
2115 addr += n;
2116 count -= n;
2117 }
2118finished:
2119 spin_unlock(&vmap_area_lock);
2120 if (!copied)
2121 return 0;
2122 return buflen;
2123}
2124
2125/**
2126 * remap_vmalloc_range_partial - map vmalloc pages to userspace
2127 * @vma: vma to cover
2128 * @uaddr: target user address to start at
2129 * @kaddr: virtual address of vmalloc kernel memory
2130 * @size: size of map area
2131 *
2132 * Returns: 0 for success, -Exxx on failure
2133 *
2134 * This function checks that @kaddr is a valid vmalloc'ed area,
2135 * and that it is big enough to cover the range starting at
2136 * @uaddr in @vma. Will return failure if that criteria isn't
2137 * met.
2138 *
2139 * Similar to remap_pfn_range() (see mm/memory.c)
2140 */
2141int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
2142 void *kaddr, unsigned long size)
2143{
2144 struct vm_struct *area;
2145
2146 size = PAGE_ALIGN(size);
2147
2148 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
2149 return -EINVAL;
2150
2151 area = find_vm_area(kaddr);
2152 if (!area)
2153 return -EINVAL;
2154
2155 if (!(area->flags & VM_USERMAP))
2156 return -EINVAL;
2157
2158 if (kaddr + size > area->addr + area->size)
2159 return -EINVAL;
2160
2161 do {
2162 struct page *page = vmalloc_to_page(kaddr);
2163 int ret;
2164
2165 ret = vm_insert_page(vma, uaddr, page);
2166 if (ret)
2167 return ret;
2168
2169 uaddr += PAGE_SIZE;
2170 kaddr += PAGE_SIZE;
2171 size -= PAGE_SIZE;
2172 } while (size > 0);
2173
2174 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
2175
2176 return 0;
2177}
2178EXPORT_SYMBOL(remap_vmalloc_range_partial);
2179
2180/**
2181 * remap_vmalloc_range - map vmalloc pages to userspace
2182 * @vma: vma to cover (map full range of vma)
2183 * @addr: vmalloc memory
2184 * @pgoff: number of pages into addr before first page to map
2185 *
2186 * Returns: 0 for success, -Exxx on failure
2187 *
2188 * This function checks that addr is a valid vmalloc'ed area, and
2189 * that it is big enough to cover the vma. Will return failure if
2190 * that criteria isn't met.
2191 *
2192 * Similar to remap_pfn_range() (see mm/memory.c)
2193 */
2194int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2195 unsigned long pgoff)
2196{
2197 return remap_vmalloc_range_partial(vma, vma->vm_start,
2198 addr + (pgoff << PAGE_SHIFT),
2199 vma->vm_end - vma->vm_start);
2200}
2201EXPORT_SYMBOL(remap_vmalloc_range);
2202
2203/*
2204 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2205 * have one.
2206 */
2207void __weak vmalloc_sync_all(void)
2208{
2209}
2210
2211
2212static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2213{
2214 pte_t ***p = data;
2215
2216 if (p) {
2217 *(*p) = pte;
2218 (*p)++;
2219 }
2220 return 0;
2221}
2222
2223/**
2224 * alloc_vm_area - allocate a range of kernel address space
2225 * @size: size of the area
2226 * @ptes: returns the PTEs for the address space
2227 *
2228 * Returns: NULL on failure, vm_struct on success
2229 *
2230 * This function reserves a range of kernel address space, and
2231 * allocates pagetables to map that range. No actual mappings
2232 * are created.
2233 *
2234 * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
2235 * allocated for the VM area are returned.
2236 */
2237struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
2238{
2239 struct vm_struct *area;
2240
2241 area = get_vm_area_caller(size, VM_IOREMAP,
2242 __builtin_return_address(0));
2243 if (area == NULL)
2244 return NULL;
2245
2246 /*
2247 * This ensures that page tables are constructed for this region
2248 * of kernel virtual address space and mapped into init_mm.
2249 */
2250 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2251 size, f, ptes ? &ptes : NULL)) {
2252 free_vm_area(area);
2253 return NULL;
2254 }
2255
2256 return area;
2257}
2258EXPORT_SYMBOL_GPL(alloc_vm_area);
2259
2260void free_vm_area(struct vm_struct *area)
2261{
2262 struct vm_struct *ret;
2263 ret = remove_vm_area(area->addr);
2264 BUG_ON(ret != area);
2265 kfree(area);
2266}
2267EXPORT_SYMBOL_GPL(free_vm_area);
2268
2269#ifdef CONFIG_SMP
2270static struct vmap_area *node_to_va(struct rb_node *n)
2271{
2272 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2273}
2274
2275/**
2276 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2277 * @end: target address
2278 * @pnext: out arg for the next vmap_area
2279 * @pprev: out arg for the previous vmap_area
2280 *
2281 * Returns: %true if either or both of next and prev are found,
2282 * %false if no vmap_area exists
2283 *
2284 * Find vmap_areas end addresses of which enclose @end. ie. if not
2285 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2286 */
2287static bool pvm_find_next_prev(unsigned long end,
2288 struct vmap_area **pnext,
2289 struct vmap_area **pprev)
2290{
2291 struct rb_node *n = vmap_area_root.rb_node;
2292 struct vmap_area *va = NULL;
2293
2294 while (n) {
2295 va = rb_entry(n, struct vmap_area, rb_node);
2296 if (end < va->va_end)
2297 n = n->rb_left;
2298 else if (end > va->va_end)
2299 n = n->rb_right;
2300 else
2301 break;
2302 }
2303
2304 if (!va)
2305 return false;
2306
2307 if (va->va_end > end) {
2308 *pnext = va;
2309 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2310 } else {
2311 *pprev = va;
2312 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2313 }
2314 return true;
2315}
2316
2317/**
2318 * pvm_determine_end - find the highest aligned address between two vmap_areas
2319 * @pnext: in/out arg for the next vmap_area
2320 * @pprev: in/out arg for the previous vmap_area
2321 * @align: alignment
2322 *
2323 * Returns: determined end address
2324 *
2325 * Find the highest aligned address between *@pnext and *@pprev below
2326 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2327 * down address is between the end addresses of the two vmap_areas.
2328 *
2329 * Please note that the address returned by this function may fall
2330 * inside *@pnext vmap_area. The caller is responsible for checking
2331 * that.
2332 */
2333static unsigned long pvm_determine_end(struct vmap_area **pnext,
2334 struct vmap_area **pprev,
2335 unsigned long align)
2336{
2337 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2338 unsigned long addr;
2339
2340 if (*pnext)
2341 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2342 else
2343 addr = vmalloc_end;
2344
2345 while (*pprev && (*pprev)->va_end > addr) {
2346 *pnext = *pprev;
2347 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2348 }
2349
2350 return addr;
2351}
2352
2353/**
2354 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2355 * @offsets: array containing offset of each area
2356 * @sizes: array containing size of each area
2357 * @nr_vms: the number of areas to allocate
2358 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2359 *
2360 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2361 * vm_structs on success, %NULL on failure
2362 *
2363 * Percpu allocator wants to use congruent vm areas so that it can
2364 * maintain the offsets among percpu areas. This function allocates
2365 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2366 * be scattered pretty far, distance between two areas easily going up
2367 * to gigabytes. To avoid interacting with regular vmallocs, these
2368 * areas are allocated from top.
2369 *
2370 * Despite its complicated look, this allocator is rather simple. It
2371 * does everything top-down and scans areas from the end looking for
2372 * matching slot. While scanning, if any of the areas overlaps with
2373 * existing vmap_area, the base address is pulled down to fit the
2374 * area. Scanning is repeated till all the areas fit and then all
2375 * necessary data structres are inserted and the result is returned.
2376 */
2377struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2378 const size_t *sizes, int nr_vms,
2379 size_t align)
2380{
2381 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2382 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2383 struct vmap_area **vas, *prev, *next;
2384 struct vm_struct **vms;
2385 int area, area2, last_area, term_area;
2386 unsigned long base, start, end, last_end;
2387 bool purged = false;
2388
2389 /* verify parameters and allocate data structures */
2390 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
2391 for (last_area = 0, area = 0; area < nr_vms; area++) {
2392 start = offsets[area];
2393 end = start + sizes[area];
2394
2395 /* is everything aligned properly? */
2396 BUG_ON(!IS_ALIGNED(offsets[area], align));
2397 BUG_ON(!IS_ALIGNED(sizes[area], align));
2398
2399 /* detect the area with the highest address */
2400 if (start > offsets[last_area])
2401 last_area = area;
2402
2403 for (area2 = 0; area2 < nr_vms; area2++) {
2404 unsigned long start2 = offsets[area2];
2405 unsigned long end2 = start2 + sizes[area2];
2406
2407 if (area2 == area)
2408 continue;
2409
2410 BUG_ON(start2 >= start && start2 < end);
2411 BUG_ON(end2 <= end && end2 > start);
2412 }
2413 }
2414 last_end = offsets[last_area] + sizes[last_area];
2415
2416 if (vmalloc_end - vmalloc_start < last_end) {
2417 WARN_ON(true);
2418 return NULL;
2419 }
2420
2421 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
2422 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
2423 if (!vas || !vms)
2424 goto err_free2;
2425
2426 for (area = 0; area < nr_vms; area++) {
2427 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2428 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2429 if (!vas[area] || !vms[area])
2430 goto err_free;
2431 }
2432retry:
2433 spin_lock(&vmap_area_lock);
2434
2435 /* start scanning - we scan from the top, begin with the last area */
2436 area = term_area = last_area;
2437 start = offsets[area];
2438 end = start + sizes[area];
2439
2440 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2441 base = vmalloc_end - last_end;
2442 goto found;
2443 }
2444 base = pvm_determine_end(&next, &prev, align) - end;
2445
2446 while (true) {
2447 BUG_ON(next && next->va_end <= base + end);
2448 BUG_ON(prev && prev->va_end > base + end);
2449
2450 /*
2451 * base might have underflowed, add last_end before
2452 * comparing.
2453 */
2454 if (base + last_end < vmalloc_start + last_end) {
2455 spin_unlock(&vmap_area_lock);
2456 if (!purged) {
2457 purge_vmap_area_lazy();
2458 purged = true;
2459 goto retry;
2460 }
2461 goto err_free;
2462 }
2463
2464 /*
2465 * If next overlaps, move base downwards so that it's
2466 * right below next and then recheck.
2467 */
2468 if (next && next->va_start < base + end) {
2469 base = pvm_determine_end(&next, &prev, align) - end;
2470 term_area = area;
2471 continue;
2472 }
2473
2474 /*
2475 * If prev overlaps, shift down next and prev and move
2476 * base so that it's right below new next and then
2477 * recheck.
2478 */
2479 if (prev && prev->va_end > base + start) {
2480 next = prev;
2481 prev = node_to_va(rb_prev(&next->rb_node));
2482 base = pvm_determine_end(&next, &prev, align) - end;
2483 term_area = area;
2484 continue;
2485 }
2486
2487 /*
2488 * This area fits, move on to the previous one. If
2489 * the previous one is the terminal one, we're done.
2490 */
2491 area = (area + nr_vms - 1) % nr_vms;
2492 if (area == term_area)
2493 break;
2494 start = offsets[area];
2495 end = start + sizes[area];
2496 pvm_find_next_prev(base + end, &next, &prev);
2497 }
2498found:
2499 /* we've found a fitting base, insert all va's */
2500 for (area = 0; area < nr_vms; area++) {
2501 struct vmap_area *va = vas[area];
2502
2503 va->va_start = base + offsets[area];
2504 va->va_end = va->va_start + sizes[area];
2505 __insert_vmap_area(va);
2506 }
2507
2508 vmap_area_pcpu_hole = base + offsets[last_area];
2509
2510 spin_unlock(&vmap_area_lock);
2511
2512 /* insert all vm's */
2513 for (area = 0; area < nr_vms; area++)
2514 setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2515 pcpu_get_vm_areas);
2516
2517 kfree(vas);
2518 return vms;
2519
2520err_free:
2521 for (area = 0; area < nr_vms; area++) {
2522 kfree(vas[area]);
2523 kfree(vms[area]);
2524 }
2525err_free2:
2526 kfree(vas);
2527 kfree(vms);
2528 return NULL;
2529}
2530
2531/**
2532 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2533 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2534 * @nr_vms: the number of allocated areas
2535 *
2536 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2537 */
2538void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2539{
2540 int i;
2541
2542 for (i = 0; i < nr_vms; i++)
2543 free_vm_area(vms[i]);
2544 kfree(vms);
2545}
2546#endif /* CONFIG_SMP */
2547
2548#ifdef CONFIG_PROC_FS
2549static void *s_start(struct seq_file *m, loff_t *pos)
2550 __acquires(&vmap_area_lock)
2551{
2552 loff_t n = *pos;
2553 struct vmap_area *va;
2554
2555 spin_lock(&vmap_area_lock);
2556 va = list_first_entry(&vmap_area_list, typeof(*va), list);
2557 while (n > 0 && &va->list != &vmap_area_list) {
2558 n--;
2559 va = list_next_entry(va, list);
2560 }
2561 if (!n && &va->list != &vmap_area_list)
2562 return va;
2563
2564 return NULL;
2565
2566}
2567
2568static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2569{
2570 struct vmap_area *va = p, *next;
2571
2572 ++*pos;
2573 next = list_next_entry(va, list);
2574 if (&next->list != &vmap_area_list)
2575 return next;
2576
2577 return NULL;
2578}
2579
2580static void s_stop(struct seq_file *m, void *p)
2581 __releases(&vmap_area_lock)
2582{
2583 spin_unlock(&vmap_area_lock);
2584}
2585
2586static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2587{
2588 if (IS_ENABLED(CONFIG_NUMA)) {
2589 unsigned int nr, *counters = m->private;
2590
2591 if (!counters)
2592 return;
2593
2594 if (v->flags & VM_UNINITIALIZED)
2595 return;
2596 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
2597 smp_rmb();
2598
2599 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2600
2601 for (nr = 0; nr < v->nr_pages; nr++)
2602 counters[page_to_nid(v->pages[nr])]++;
2603
2604 for_each_node_state(nr, N_HIGH_MEMORY)
2605 if (counters[nr])
2606 seq_printf(m, " N%u=%u", nr, counters[nr]);
2607 }
2608}
2609
2610static int s_show(struct seq_file *m, void *p)
2611{
2612 struct vmap_area *va = p;
2613 struct vm_struct *v;
2614
2615 /*
2616 * s_show can encounter race with remove_vm_area, !VM_VM_AREA on
2617 * behalf of vmap area is being tear down or vm_map_ram allocation.
2618 */
2619 if (!(va->flags & VM_VM_AREA))
2620 return 0;
2621
2622 v = va->vm;
2623
2624 seq_printf(m, "0x%pK-0x%pK %7ld",
2625 v->addr, v->addr + v->size, v->size);
2626
2627 if (v->caller)
2628 seq_printf(m, " %pS", v->caller);
2629
2630 if (v->nr_pages)
2631 seq_printf(m, " pages=%d", v->nr_pages);
2632
2633 if (v->phys_addr)
2634 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2635
2636 if (v->flags & VM_IOREMAP)
2637 seq_puts(m, " ioremap");
2638
2639 if (v->flags & VM_ALLOC)
2640 seq_puts(m, " vmalloc");
2641
2642 if (v->flags & VM_MAP)
2643 seq_puts(m, " vmap");
2644
2645 if (v->flags & VM_USERMAP)
2646 seq_puts(m, " user");
2647
2648 if (is_vmalloc_addr(v->pages))
2649 seq_puts(m, " vpages");
2650
2651 show_numa_info(m, v);
2652 seq_putc(m, '\n');
2653 return 0;
2654}
2655
2656static const struct seq_operations vmalloc_op = {
2657 .start = s_start,
2658 .next = s_next,
2659 .stop = s_stop,
2660 .show = s_show,
2661};
2662
2663static int vmalloc_open(struct inode *inode, struct file *file)
2664{
2665 if (IS_ENABLED(CONFIG_NUMA))
2666 return seq_open_private(file, &vmalloc_op,
2667 nr_node_ids * sizeof(unsigned int));
2668 else
2669 return seq_open(file, &vmalloc_op);
2670}
2671
2672static const struct file_operations proc_vmalloc_operations = {
2673 .open = vmalloc_open,
2674 .read = seq_read,
2675 .llseek = seq_lseek,
2676 .release = seq_release_private,
2677};
2678
2679static int __init proc_vmalloc_init(void)
2680{
2681 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2682 return 0;
2683}
2684module_init(proc_vmalloc_init);
2685
2686#endif
2687