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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.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 <asm/uaccess.h>
31#include <asm/tlbflush.h>
32#include <asm/shmparam.h>
33
34/*** Page table manipulation functions ***/
35
36static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
37{
38 pte_t *pte;
39
40 pte = pte_offset_kernel(pmd, addr);
41 do {
42 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
43 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
44 } while (pte++, addr += PAGE_SIZE, addr != end);
45}
46
47static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
48{
49 pmd_t *pmd;
50 unsigned long next;
51
52 pmd = pmd_offset(pud, addr);
53 do {
54 next = pmd_addr_end(addr, end);
55 if (pmd_none_or_clear_bad(pmd))
56 continue;
57 vunmap_pte_range(pmd, addr, next);
58 } while (pmd++, addr = next, addr != end);
59}
60
61static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
62{
63 pud_t *pud;
64 unsigned long next;
65
66 pud = pud_offset(pgd, addr);
67 do {
68 next = pud_addr_end(addr, end);
69 if (pud_none_or_clear_bad(pud))
70 continue;
71 vunmap_pmd_range(pud, addr, next);
72 } while (pud++, addr = next, addr != end);
73}
74
75static void vunmap_page_range(unsigned long addr, unsigned long end)
76{
77 pgd_t *pgd;
78 unsigned long next;
79
80 BUG_ON(addr >= end);
81 pgd = pgd_offset_k(addr);
82 do {
83 next = pgd_addr_end(addr, end);
84 if (pgd_none_or_clear_bad(pgd))
85 continue;
86 vunmap_pud_range(pgd, addr, next);
87 } while (pgd++, addr = next, addr != end);
88}
89
90static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
91 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
92{
93 pte_t *pte;
94
95 /*
96 * nr is a running index into the array which helps higher level
97 * callers keep track of where we're up to.
98 */
99
100 pte = pte_alloc_kernel(pmd, addr);
101 if (!pte)
102 return -ENOMEM;
103 do {
104 struct page *page = pages[*nr];
105
106 if (WARN_ON(!pte_none(*pte)))
107 return -EBUSY;
108 if (WARN_ON(!page))
109 return -ENOMEM;
110 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
111 (*nr)++;
112 } while (pte++, addr += PAGE_SIZE, addr != end);
113 return 0;
114}
115
116static int vmap_pmd_range(pud_t *pud, unsigned long addr,
117 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
118{
119 pmd_t *pmd;
120 unsigned long next;
121
122 pmd = pmd_alloc(&init_mm, pud, addr);
123 if (!pmd)
124 return -ENOMEM;
125 do {
126 next = pmd_addr_end(addr, end);
127 if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
128 return -ENOMEM;
129 } while (pmd++, addr = next, addr != end);
130 return 0;
131}
132
133static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
134 unsigned long end, pgprot_t prot, struct page **pages, int *nr)
135{
136 pud_t *pud;
137 unsigned long next;
138
139 pud = pud_alloc(&init_mm, pgd, addr);
140 if (!pud)
141 return -ENOMEM;
142 do {
143 next = pud_addr_end(addr, end);
144 if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
145 return -ENOMEM;
146 } while (pud++, addr = next, addr != end);
147 return 0;
148}
149
150/*
151 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
152 * will have pfns corresponding to the "pages" array.
153 *
154 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
155 */
156static int vmap_page_range_noflush(unsigned long start, unsigned long end,
157 pgprot_t prot, struct page **pages)
158{
159 pgd_t *pgd;
160 unsigned long next;
161 unsigned long addr = start;
162 int err = 0;
163 int nr = 0;
164
165 BUG_ON(addr >= end);
166 pgd = pgd_offset_k(addr);
167 do {
168 next = pgd_addr_end(addr, end);
169 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
170 if (err)
171 return err;
172 } while (pgd++, addr = next, addr != end);
173
174 return nr;
175}
176
177static int vmap_page_range(unsigned long start, unsigned long end,
178 pgprot_t prot, struct page **pages)
179{
180 int ret;
181
182 ret = vmap_page_range_noflush(start, end, prot, pages);
183 flush_cache_vmap(start, end);
184 return ret;
185}
186
187int is_vmalloc_or_module_addr(const void *x)
188{
189 /*
190 * ARM, x86-64 and sparc64 put modules in a special place,
191 * and fall back on vmalloc() if that fails. Others
192 * just put it in the vmalloc space.
193 */
194#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
195 unsigned long addr = (unsigned long)x;
196 if (addr >= MODULES_VADDR && addr < MODULES_END)
197 return 1;
198#endif
199 return is_vmalloc_addr(x);
200}
201
202/*
203 * Walk a vmap address to the struct page it maps.
204 */
205struct page *vmalloc_to_page(const void *vmalloc_addr)
206{
207 unsigned long addr = (unsigned long) vmalloc_addr;
208 struct page *page = NULL;
209 pgd_t *pgd = pgd_offset_k(addr);
210
211 /*
212 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
213 * architectures that do not vmalloc module space
214 */
215 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
216
217 if (!pgd_none(*pgd)) {
218 pud_t *pud = pud_offset(pgd, addr);
219 if (!pud_none(*pud)) {
220 pmd_t *pmd = pmd_offset(pud, addr);
221 if (!pmd_none(*pmd)) {
222 pte_t *ptep, pte;
223
224 ptep = pte_offset_map(pmd, addr);
225 pte = *ptep;
226 if (pte_present(pte))
227 page = pte_page(pte);
228 pte_unmap(ptep);
229 }
230 }
231 }
232 return page;
233}
234EXPORT_SYMBOL(vmalloc_to_page);
235
236/*
237 * Map a vmalloc()-space virtual address to the physical page frame number.
238 */
239unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
240{
241 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
242}
243EXPORT_SYMBOL(vmalloc_to_pfn);
244
245
246/*** Global kva allocator ***/
247
248#define VM_LAZY_FREE 0x01
249#define VM_LAZY_FREEING 0x02
250#define VM_VM_AREA 0x04
251
252struct vmap_area {
253 unsigned long va_start;
254 unsigned long va_end;
255 unsigned long flags;
256 struct rb_node rb_node; /* address sorted rbtree */
257 struct list_head list; /* address sorted list */
258 struct list_head purge_list; /* "lazy purge" list */
259 void *private;
260 struct rcu_head rcu_head;
261};
262
263static DEFINE_SPINLOCK(vmap_area_lock);
264static LIST_HEAD(vmap_area_list);
265static struct rb_root vmap_area_root = RB_ROOT;
266
267/* The vmap cache globals are protected by vmap_area_lock */
268static struct rb_node *free_vmap_cache;
269static unsigned long cached_hole_size;
270static unsigned long cached_vstart;
271static unsigned long cached_align;
272
273static unsigned long vmap_area_pcpu_hole;
274
275static struct vmap_area *__find_vmap_area(unsigned long addr)
276{
277 struct rb_node *n = vmap_area_root.rb_node;
278
279 while (n) {
280 struct vmap_area *va;
281
282 va = rb_entry(n, struct vmap_area, rb_node);
283 if (addr < va->va_start)
284 n = n->rb_left;
285 else if (addr > va->va_start)
286 n = n->rb_right;
287 else
288 return va;
289 }
290
291 return NULL;
292}
293
294static void __insert_vmap_area(struct vmap_area *va)
295{
296 struct rb_node **p = &vmap_area_root.rb_node;
297 struct rb_node *parent = NULL;
298 struct rb_node *tmp;
299
300 while (*p) {
301 struct vmap_area *tmp_va;
302
303 parent = *p;
304 tmp_va = rb_entry(parent, struct vmap_area, rb_node);
305 if (va->va_start < tmp_va->va_end)
306 p = &(*p)->rb_left;
307 else if (va->va_end > tmp_va->va_start)
308 p = &(*p)->rb_right;
309 else
310 BUG();
311 }
312
313 rb_link_node(&va->rb_node, parent, p);
314 rb_insert_color(&va->rb_node, &vmap_area_root);
315
316 /* address-sort this list so it is usable like the vmlist */
317 tmp = rb_prev(&va->rb_node);
318 if (tmp) {
319 struct vmap_area *prev;
320 prev = rb_entry(tmp, struct vmap_area, rb_node);
321 list_add_rcu(&va->list, &prev->list);
322 } else
323 list_add_rcu(&va->list, &vmap_area_list);
324}
325
326static void purge_vmap_area_lazy(void);
327
328/*
329 * Allocate a region of KVA of the specified size and alignment, within the
330 * vstart and vend.
331 */
332static struct vmap_area *alloc_vmap_area(unsigned long size,
333 unsigned long align,
334 unsigned long vstart, unsigned long vend,
335 int node, gfp_t gfp_mask)
336{
337 struct vmap_area *va;
338 struct rb_node *n;
339 unsigned long addr;
340 int purged = 0;
341 struct vmap_area *first;
342
343 BUG_ON(!size);
344 BUG_ON(size & ~PAGE_MASK);
345 BUG_ON(!is_power_of_2(align));
346
347 va = kmalloc_node(sizeof(struct vmap_area),
348 gfp_mask & GFP_RECLAIM_MASK, node);
349 if (unlikely(!va))
350 return ERR_PTR(-ENOMEM);
351
352retry:
353 spin_lock(&vmap_area_lock);
354 /*
355 * Invalidate cache if we have more permissive parameters.
356 * cached_hole_size notes the largest hole noticed _below_
357 * the vmap_area cached in free_vmap_cache: if size fits
358 * into that hole, we want to scan from vstart to reuse
359 * the hole instead of allocating above free_vmap_cache.
360 * Note that __free_vmap_area may update free_vmap_cache
361 * without updating cached_hole_size or cached_align.
362 */
363 if (!free_vmap_cache ||
364 size < cached_hole_size ||
365 vstart < cached_vstart ||
366 align < cached_align) {
367nocache:
368 cached_hole_size = 0;
369 free_vmap_cache = NULL;
370 }
371 /* record if we encounter less permissive parameters */
372 cached_vstart = vstart;
373 cached_align = align;
374
375 /* find starting point for our search */
376 if (free_vmap_cache) {
377 first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
378 addr = ALIGN(first->va_end, align);
379 if (addr < vstart)
380 goto nocache;
381 if (addr + size - 1 < addr)
382 goto overflow;
383
384 } else {
385 addr = ALIGN(vstart, align);
386 if (addr + size - 1 < addr)
387 goto overflow;
388
389 n = vmap_area_root.rb_node;
390 first = NULL;
391
392 while (n) {
393 struct vmap_area *tmp;
394 tmp = rb_entry(n, struct vmap_area, rb_node);
395 if (tmp->va_end >= addr) {
396 first = tmp;
397 if (tmp->va_start <= addr)
398 break;
399 n = n->rb_left;
400 } else
401 n = n->rb_right;
402 }
403
404 if (!first)
405 goto found;
406 }
407
408 /* from the starting point, walk areas until a suitable hole is found */
409 while (addr + size > first->va_start && addr + size <= vend) {
410 if (addr + cached_hole_size < first->va_start)
411 cached_hole_size = first->va_start - addr;
412 addr = ALIGN(first->va_end, align);
413 if (addr + size - 1 < addr)
414 goto overflow;
415
416 n = rb_next(&first->rb_node);
417 if (n)
418 first = rb_entry(n, struct vmap_area, rb_node);
419 else
420 goto found;
421 }
422
423found:
424 if (addr + size > vend)
425 goto overflow;
426
427 va->va_start = addr;
428 va->va_end = addr + size;
429 va->flags = 0;
430 __insert_vmap_area(va);
431 free_vmap_cache = &va->rb_node;
432 spin_unlock(&vmap_area_lock);
433
434 BUG_ON(va->va_start & (align-1));
435 BUG_ON(va->va_start < vstart);
436 BUG_ON(va->va_end > vend);
437
438 return va;
439
440overflow:
441 spin_unlock(&vmap_area_lock);
442 if (!purged) {
443 purge_vmap_area_lazy();
444 purged = 1;
445 goto retry;
446 }
447 if (printk_ratelimit())
448 printk(KERN_WARNING
449 "vmap allocation for size %lu failed: "
450 "use vmalloc=<size> to increase size.\n", size);
451 kfree(va);
452 return ERR_PTR(-EBUSY);
453}
454
455static void __free_vmap_area(struct vmap_area *va)
456{
457 BUG_ON(RB_EMPTY_NODE(&va->rb_node));
458
459 if (free_vmap_cache) {
460 if (va->va_end < cached_vstart) {
461 free_vmap_cache = NULL;
462 } else {
463 struct vmap_area *cache;
464 cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
465 if (va->va_start <= cache->va_start) {
466 free_vmap_cache = rb_prev(&va->rb_node);
467 /*
468 * We don't try to update cached_hole_size or
469 * cached_align, but it won't go very wrong.
470 */
471 }
472 }
473 }
474 rb_erase(&va->rb_node, &vmap_area_root);
475 RB_CLEAR_NODE(&va->rb_node);
476 list_del_rcu(&va->list);
477
478 /*
479 * Track the highest possible candidate for pcpu area
480 * allocation. Areas outside of vmalloc area can be returned
481 * here too, consider only end addresses which fall inside
482 * vmalloc area proper.
483 */
484 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
485 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
486
487 kfree_rcu(va, rcu_head);
488}
489
490/*
491 * Free a region of KVA allocated by alloc_vmap_area
492 */
493static void free_vmap_area(struct vmap_area *va)
494{
495 spin_lock(&vmap_area_lock);
496 __free_vmap_area(va);
497 spin_unlock(&vmap_area_lock);
498}
499
500/*
501 * Clear the pagetable entries of a given vmap_area
502 */
503static void unmap_vmap_area(struct vmap_area *va)
504{
505 vunmap_page_range(va->va_start, va->va_end);
506}
507
508static void vmap_debug_free_range(unsigned long start, unsigned long end)
509{
510 /*
511 * Unmap page tables and force a TLB flush immediately if
512 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
513 * bugs similarly to those in linear kernel virtual address
514 * space after a page has been freed.
515 *
516 * All the lazy freeing logic is still retained, in order to
517 * minimise intrusiveness of this debugging feature.
518 *
519 * This is going to be *slow* (linear kernel virtual address
520 * debugging doesn't do a broadcast TLB flush so it is a lot
521 * faster).
522 */
523#ifdef CONFIG_DEBUG_PAGEALLOC
524 vunmap_page_range(start, end);
525 flush_tlb_kernel_range(start, end);
526#endif
527}
528
529/*
530 * lazy_max_pages is the maximum amount of virtual address space we gather up
531 * before attempting to purge with a TLB flush.
532 *
533 * There is a tradeoff here: a larger number will cover more kernel page tables
534 * and take slightly longer to purge, but it will linearly reduce the number of
535 * global TLB flushes that must be performed. It would seem natural to scale
536 * this number up linearly with the number of CPUs (because vmapping activity
537 * could also scale linearly with the number of CPUs), however it is likely
538 * that in practice, workloads might be constrained in other ways that mean
539 * vmap activity will not scale linearly with CPUs. Also, I want to be
540 * conservative and not introduce a big latency on huge systems, so go with
541 * a less aggressive log scale. It will still be an improvement over the old
542 * code, and it will be simple to change the scale factor if we find that it
543 * becomes a problem on bigger systems.
544 */
545static unsigned long lazy_max_pages(void)
546{
547 unsigned int log;
548
549 log = fls(num_online_cpus());
550
551 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
552}
553
554static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
555
556/* for per-CPU blocks */
557static void purge_fragmented_blocks_allcpus(void);
558
559/*
560 * called before a call to iounmap() if the caller wants vm_area_struct's
561 * immediately freed.
562 */
563void set_iounmap_nonlazy(void)
564{
565 atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
566}
567
568/*
569 * Purges all lazily-freed vmap areas.
570 *
571 * If sync is 0 then don't purge if there is already a purge in progress.
572 * If force_flush is 1, then flush kernel TLBs between *start and *end even
573 * if we found no lazy vmap areas to unmap (callers can use this to optimise
574 * their own TLB flushing).
575 * Returns with *start = min(*start, lowest purged address)
576 * *end = max(*end, highest purged address)
577 */
578static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
579 int sync, int force_flush)
580{
581 static DEFINE_SPINLOCK(purge_lock);
582 LIST_HEAD(valist);
583 struct vmap_area *va;
584 struct vmap_area *n_va;
585 int nr = 0;
586
587 /*
588 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
589 * should not expect such behaviour. This just simplifies locking for
590 * the case that isn't actually used at the moment anyway.
591 */
592 if (!sync && !force_flush) {
593 if (!spin_trylock(&purge_lock))
594 return;
595 } else
596 spin_lock(&purge_lock);
597
598 if (sync)
599 purge_fragmented_blocks_allcpus();
600
601 rcu_read_lock();
602 list_for_each_entry_rcu(va, &vmap_area_list, list) {
603 if (va->flags & VM_LAZY_FREE) {
604 if (va->va_start < *start)
605 *start = va->va_start;
606 if (va->va_end > *end)
607 *end = va->va_end;
608 nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
609 list_add_tail(&va->purge_list, &valist);
610 va->flags |= VM_LAZY_FREEING;
611 va->flags &= ~VM_LAZY_FREE;
612 }
613 }
614 rcu_read_unlock();
615
616 if (nr)
617 atomic_sub(nr, &vmap_lazy_nr);
618
619 if (nr || force_flush)
620 flush_tlb_kernel_range(*start, *end);
621
622 if (nr) {
623 spin_lock(&vmap_area_lock);
624 list_for_each_entry_safe(va, n_va, &valist, purge_list)
625 __free_vmap_area(va);
626 spin_unlock(&vmap_area_lock);
627 }
628 spin_unlock(&purge_lock);
629}
630
631/*
632 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
633 * is already purging.
634 */
635static void try_purge_vmap_area_lazy(void)
636{
637 unsigned long start = ULONG_MAX, end = 0;
638
639 __purge_vmap_area_lazy(&start, &end, 0, 0);
640}
641
642/*
643 * Kick off a purge of the outstanding lazy areas.
644 */
645static void purge_vmap_area_lazy(void)
646{
647 unsigned long start = ULONG_MAX, end = 0;
648
649 __purge_vmap_area_lazy(&start, &end, 1, 0);
650}
651
652/*
653 * Free a vmap area, caller ensuring that the area has been unmapped
654 * and flush_cache_vunmap had been called for the correct range
655 * previously.
656 */
657static void free_vmap_area_noflush(struct vmap_area *va)
658{
659 va->flags |= VM_LAZY_FREE;
660 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
661 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
662 try_purge_vmap_area_lazy();
663}
664
665/*
666 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
667 * called for the correct range previously.
668 */
669static void free_unmap_vmap_area_noflush(struct vmap_area *va)
670{
671 unmap_vmap_area(va);
672 free_vmap_area_noflush(va);
673}
674
675/*
676 * Free and unmap a vmap area
677 */
678static void free_unmap_vmap_area(struct vmap_area *va)
679{
680 flush_cache_vunmap(va->va_start, va->va_end);
681 free_unmap_vmap_area_noflush(va);
682}
683
684static struct vmap_area *find_vmap_area(unsigned long addr)
685{
686 struct vmap_area *va;
687
688 spin_lock(&vmap_area_lock);
689 va = __find_vmap_area(addr);
690 spin_unlock(&vmap_area_lock);
691
692 return va;
693}
694
695static void free_unmap_vmap_area_addr(unsigned long addr)
696{
697 struct vmap_area *va;
698
699 va = find_vmap_area(addr);
700 BUG_ON(!va);
701 free_unmap_vmap_area(va);
702}
703
704
705/*** Per cpu kva allocator ***/
706
707/*
708 * vmap space is limited especially on 32 bit architectures. Ensure there is
709 * room for at least 16 percpu vmap blocks per CPU.
710 */
711/*
712 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
713 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
714 * instead (we just need a rough idea)
715 */
716#if BITS_PER_LONG == 32
717#define VMALLOC_SPACE (128UL*1024*1024)
718#else
719#define VMALLOC_SPACE (128UL*1024*1024*1024)
720#endif
721
722#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
723#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
724#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
725#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
726#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
727#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
728#define VMAP_BBMAP_BITS \
729 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
730 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
731 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
732
733#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
734
735static bool vmap_initialized __read_mostly = false;
736
737struct vmap_block_queue {
738 spinlock_t lock;
739 struct list_head free;
740};
741
742struct vmap_block {
743 spinlock_t lock;
744 struct vmap_area *va;
745 struct vmap_block_queue *vbq;
746 unsigned long free, dirty;
747 DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
748 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
749 struct list_head free_list;
750 struct rcu_head rcu_head;
751 struct list_head purge;
752};
753
754/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
755static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
756
757/*
758 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
759 * in the free path. Could get rid of this if we change the API to return a
760 * "cookie" from alloc, to be passed to free. But no big deal yet.
761 */
762static DEFINE_SPINLOCK(vmap_block_tree_lock);
763static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);
764
765/*
766 * We should probably have a fallback mechanism to allocate virtual memory
767 * out of partially filled vmap blocks. However vmap block sizing should be
768 * fairly reasonable according to the vmalloc size, so it shouldn't be a
769 * big problem.
770 */
771
772static unsigned long addr_to_vb_idx(unsigned long addr)
773{
774 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
775 addr /= VMAP_BLOCK_SIZE;
776 return addr;
777}
778
779static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
780{
781 struct vmap_block_queue *vbq;
782 struct vmap_block *vb;
783 struct vmap_area *va;
784 unsigned long vb_idx;
785 int node, err;
786
787 node = numa_node_id();
788
789 vb = kmalloc_node(sizeof(struct vmap_block),
790 gfp_mask & GFP_RECLAIM_MASK, node);
791 if (unlikely(!vb))
792 return ERR_PTR(-ENOMEM);
793
794 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
795 VMALLOC_START, VMALLOC_END,
796 node, gfp_mask);
797 if (IS_ERR(va)) {
798 kfree(vb);
799 return ERR_CAST(va);
800 }
801
802 err = radix_tree_preload(gfp_mask);
803 if (unlikely(err)) {
804 kfree(vb);
805 free_vmap_area(va);
806 return ERR_PTR(err);
807 }
808
809 spin_lock_init(&vb->lock);
810 vb->va = va;
811 vb->free = VMAP_BBMAP_BITS;
812 vb->dirty = 0;
813 bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS);
814 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
815 INIT_LIST_HEAD(&vb->free_list);
816
817 vb_idx = addr_to_vb_idx(va->va_start);
818 spin_lock(&vmap_block_tree_lock);
819 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
820 spin_unlock(&vmap_block_tree_lock);
821 BUG_ON(err);
822 radix_tree_preload_end();
823
824 vbq = &get_cpu_var(vmap_block_queue);
825 vb->vbq = vbq;
826 spin_lock(&vbq->lock);
827 list_add_rcu(&vb->free_list, &vbq->free);
828 spin_unlock(&vbq->lock);
829 put_cpu_var(vmap_block_queue);
830
831 return vb;
832}
833
834static void free_vmap_block(struct vmap_block *vb)
835{
836 struct vmap_block *tmp;
837 unsigned long vb_idx;
838
839 vb_idx = addr_to_vb_idx(vb->va->va_start);
840 spin_lock(&vmap_block_tree_lock);
841 tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
842 spin_unlock(&vmap_block_tree_lock);
843 BUG_ON(tmp != vb);
844
845 free_vmap_area_noflush(vb->va);
846 kfree_rcu(vb, rcu_head);
847}
848
849static void purge_fragmented_blocks(int cpu)
850{
851 LIST_HEAD(purge);
852 struct vmap_block *vb;
853 struct vmap_block *n_vb;
854 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
855
856 rcu_read_lock();
857 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
858
859 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
860 continue;
861
862 spin_lock(&vb->lock);
863 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
864 vb->free = 0; /* prevent further allocs after releasing lock */
865 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
866 bitmap_fill(vb->alloc_map, VMAP_BBMAP_BITS);
867 bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
868 spin_lock(&vbq->lock);
869 list_del_rcu(&vb->free_list);
870 spin_unlock(&vbq->lock);
871 spin_unlock(&vb->lock);
872 list_add_tail(&vb->purge, &purge);
873 } else
874 spin_unlock(&vb->lock);
875 }
876 rcu_read_unlock();
877
878 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
879 list_del(&vb->purge);
880 free_vmap_block(vb);
881 }
882}
883
884static void purge_fragmented_blocks_thiscpu(void)
885{
886 purge_fragmented_blocks(smp_processor_id());
887}
888
889static void purge_fragmented_blocks_allcpus(void)
890{
891 int cpu;
892
893 for_each_possible_cpu(cpu)
894 purge_fragmented_blocks(cpu);
895}
896
897static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
898{
899 struct vmap_block_queue *vbq;
900 struct vmap_block *vb;
901 unsigned long addr = 0;
902 unsigned int order;
903 int purge = 0;
904
905 BUG_ON(size & ~PAGE_MASK);
906 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
907 order = get_order(size);
908
909again:
910 rcu_read_lock();
911 vbq = &get_cpu_var(vmap_block_queue);
912 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
913 int i;
914
915 spin_lock(&vb->lock);
916 if (vb->free < 1UL << order)
917 goto next;
918
919 i = bitmap_find_free_region(vb->alloc_map,
920 VMAP_BBMAP_BITS, order);
921
922 if (i < 0) {
923 if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
924 /* fragmented and no outstanding allocations */
925 BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
926 purge = 1;
927 }
928 goto next;
929 }
930 addr = vb->va->va_start + (i << PAGE_SHIFT);
931 BUG_ON(addr_to_vb_idx(addr) !=
932 addr_to_vb_idx(vb->va->va_start));
933 vb->free -= 1UL << order;
934 if (vb->free == 0) {
935 spin_lock(&vbq->lock);
936 list_del_rcu(&vb->free_list);
937 spin_unlock(&vbq->lock);
938 }
939 spin_unlock(&vb->lock);
940 break;
941next:
942 spin_unlock(&vb->lock);
943 }
944
945 if (purge)
946 purge_fragmented_blocks_thiscpu();
947
948 put_cpu_var(vmap_block_queue);
949 rcu_read_unlock();
950
951 if (!addr) {
952 vb = new_vmap_block(gfp_mask);
953 if (IS_ERR(vb))
954 return vb;
955 goto again;
956 }
957
958 return (void *)addr;
959}
960
961static void vb_free(const void *addr, unsigned long size)
962{
963 unsigned long offset;
964 unsigned long vb_idx;
965 unsigned int order;
966 struct vmap_block *vb;
967
968 BUG_ON(size & ~PAGE_MASK);
969 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
970
971 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);
972
973 order = get_order(size);
974
975 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);
976
977 vb_idx = addr_to_vb_idx((unsigned long)addr);
978 rcu_read_lock();
979 vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
980 rcu_read_unlock();
981 BUG_ON(!vb);
982
983 vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);
984
985 spin_lock(&vb->lock);
986 BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
987
988 vb->dirty += 1UL << order;
989 if (vb->dirty == VMAP_BBMAP_BITS) {
990 BUG_ON(vb->free);
991 spin_unlock(&vb->lock);
992 free_vmap_block(vb);
993 } else
994 spin_unlock(&vb->lock);
995}
996
997/**
998 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
999 *
1000 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
1001 * to amortize TLB flushing overheads. What this means is that any page you
1002 * have now, may, in a former life, have been mapped into kernel virtual
1003 * address by the vmap layer and so there might be some CPUs with TLB entries
1004 * still referencing that page (additional to the regular 1:1 kernel mapping).
1005 *
1006 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
1007 * be sure that none of the pages we have control over will have any aliases
1008 * from the vmap layer.
1009 */
1010void vm_unmap_aliases(void)
1011{
1012 unsigned long start = ULONG_MAX, end = 0;
1013 int cpu;
1014 int flush = 0;
1015
1016 if (unlikely(!vmap_initialized))
1017 return;
1018
1019 for_each_possible_cpu(cpu) {
1020 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1021 struct vmap_block *vb;
1022
1023 rcu_read_lock();
1024 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1025 int i;
1026
1027 spin_lock(&vb->lock);
1028 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1029 while (i < VMAP_BBMAP_BITS) {
1030 unsigned long s, e;
1031 int j;
1032 j = find_next_zero_bit(vb->dirty_map,
1033 VMAP_BBMAP_BITS, i);
1034
1035 s = vb->va->va_start + (i << PAGE_SHIFT);
1036 e = vb->va->va_start + (j << PAGE_SHIFT);
1037 flush = 1;
1038
1039 if (s < start)
1040 start = s;
1041 if (e > end)
1042 end = e;
1043
1044 i = j;
1045 i = find_next_bit(vb->dirty_map,
1046 VMAP_BBMAP_BITS, i);
1047 }
1048 spin_unlock(&vb->lock);
1049 }
1050 rcu_read_unlock();
1051 }
1052
1053 __purge_vmap_area_lazy(&start, &end, 1, flush);
1054}
1055EXPORT_SYMBOL_GPL(vm_unmap_aliases);
1056
1057/**
1058 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
1059 * @mem: the pointer returned by vm_map_ram
1060 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
1061 */
1062void vm_unmap_ram(const void *mem, unsigned int count)
1063{
1064 unsigned long size = count << PAGE_SHIFT;
1065 unsigned long addr = (unsigned long)mem;
1066
1067 BUG_ON(!addr);
1068 BUG_ON(addr < VMALLOC_START);
1069 BUG_ON(addr > VMALLOC_END);
1070 BUG_ON(addr & (PAGE_SIZE-1));
1071
1072 debug_check_no_locks_freed(mem, size);
1073 vmap_debug_free_range(addr, addr+size);
1074
1075 if (likely(count <= VMAP_MAX_ALLOC))
1076 vb_free(mem, size);
1077 else
1078 free_unmap_vmap_area_addr(addr);
1079}
1080EXPORT_SYMBOL(vm_unmap_ram);
1081
1082/**
1083 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
1084 * @pages: an array of pointers to the pages to be mapped
1085 * @count: number of pages
1086 * @node: prefer to allocate data structures on this node
1087 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1088 *
1089 * Returns: a pointer to the address that has been mapped, or %NULL on failure
1090 */
1091void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
1092{
1093 unsigned long size = count << PAGE_SHIFT;
1094 unsigned long addr;
1095 void *mem;
1096
1097 if (likely(count <= VMAP_MAX_ALLOC)) {
1098 mem = vb_alloc(size, GFP_KERNEL);
1099 if (IS_ERR(mem))
1100 return NULL;
1101 addr = (unsigned long)mem;
1102 } else {
1103 struct vmap_area *va;
1104 va = alloc_vmap_area(size, PAGE_SIZE,
1105 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
1106 if (IS_ERR(va))
1107 return NULL;
1108
1109 addr = va->va_start;
1110 mem = (void *)addr;
1111 }
1112 if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
1113 vm_unmap_ram(mem, count);
1114 return NULL;
1115 }
1116 return mem;
1117}
1118EXPORT_SYMBOL(vm_map_ram);
1119
1120/**
1121 * vm_area_register_early - register vmap area early during boot
1122 * @vm: vm_struct to register
1123 * @align: requested alignment
1124 *
1125 * This function is used to register kernel vm area before
1126 * vmalloc_init() is called. @vm->size and @vm->flags should contain
1127 * proper values on entry and other fields should be zero. On return,
1128 * vm->addr contains the allocated address.
1129 *
1130 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
1131 */
1132void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1133{
1134 static size_t vm_init_off __initdata;
1135 unsigned long addr;
1136
1137 addr = ALIGN(VMALLOC_START + vm_init_off, align);
1138 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1139
1140 vm->addr = (void *)addr;
1141
1142 vm->next = vmlist;
1143 vmlist = vm;
1144}
1145
1146void __init vmalloc_init(void)
1147{
1148 struct vmap_area *va;
1149 struct vm_struct *tmp;
1150 int i;
1151
1152 for_each_possible_cpu(i) {
1153 struct vmap_block_queue *vbq;
1154
1155 vbq = &per_cpu(vmap_block_queue, i);
1156 spin_lock_init(&vbq->lock);
1157 INIT_LIST_HEAD(&vbq->free);
1158 }
1159
1160 /* Import existing vmlist entries. */
1161 for (tmp = vmlist; tmp; tmp = tmp->next) {
1162 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1163 va->flags = tmp->flags | VM_VM_AREA;
1164 va->va_start = (unsigned long)tmp->addr;
1165 va->va_end = va->va_start + tmp->size;
1166 __insert_vmap_area(va);
1167 }
1168
1169 vmap_area_pcpu_hole = VMALLOC_END;
1170
1171 vmap_initialized = true;
1172}
1173
1174/**
1175 * map_kernel_range_noflush - map kernel VM area with the specified pages
1176 * @addr: start of the VM area to map
1177 * @size: size of the VM area to map
1178 * @prot: page protection flags to use
1179 * @pages: pages to map
1180 *
1181 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size
1182 * specify should have been allocated using get_vm_area() and its
1183 * friends.
1184 *
1185 * NOTE:
1186 * This function does NOT do any cache flushing. The caller is
1187 * responsible for calling flush_cache_vmap() on to-be-mapped areas
1188 * before calling this function.
1189 *
1190 * RETURNS:
1191 * The number of pages mapped on success, -errno on failure.
1192 */
1193int map_kernel_range_noflush(unsigned long addr, unsigned long size,
1194 pgprot_t prot, struct page **pages)
1195{
1196 return vmap_page_range_noflush(addr, addr + size, prot, pages);
1197}
1198
1199/**
1200 * unmap_kernel_range_noflush - unmap kernel VM area
1201 * @addr: start of the VM area to unmap
1202 * @size: size of the VM area to unmap
1203 *
1204 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size
1205 * specify should have been allocated using get_vm_area() and its
1206 * friends.
1207 *
1208 * NOTE:
1209 * This function does NOT do any cache flushing. The caller is
1210 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
1211 * before calling this function and flush_tlb_kernel_range() after.
1212 */
1213void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
1214{
1215 vunmap_page_range(addr, addr + size);
1216}
1217EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1218
1219/**
1220 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
1221 * @addr: start of the VM area to unmap
1222 * @size: size of the VM area to unmap
1223 *
1224 * Similar to unmap_kernel_range_noflush() but flushes vcache before
1225 * the unmapping and tlb after.
1226 */
1227void unmap_kernel_range(unsigned long addr, unsigned long size)
1228{
1229 unsigned long end = addr + size;
1230
1231 flush_cache_vunmap(addr, end);
1232 vunmap_page_range(addr, end);
1233 flush_tlb_kernel_range(addr, end);
1234}
1235
1236int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
1237{
1238 unsigned long addr = (unsigned long)area->addr;
1239 unsigned long end = addr + area->size - PAGE_SIZE;
1240 int err;
1241
1242 err = vmap_page_range(addr, end, prot, *pages);
1243 if (err > 0) {
1244 *pages += err;
1245 err = 0;
1246 }
1247
1248 return err;
1249}
1250EXPORT_SYMBOL_GPL(map_vm_area);
1251
1252/*** Old vmalloc interfaces ***/
1253DEFINE_RWLOCK(vmlist_lock);
1254struct vm_struct *vmlist;
1255
1256static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1257 unsigned long flags, void *caller)
1258{
1259 struct vm_struct *tmp, **p;
1260
1261 vm->flags = flags;
1262 vm->addr = (void *)va->va_start;
1263 vm->size = va->va_end - va->va_start;
1264 vm->caller = caller;
1265 va->private = vm;
1266 va->flags |= VM_VM_AREA;
1267
1268 write_lock(&vmlist_lock);
1269 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
1270 if (tmp->addr >= vm->addr)
1271 break;
1272 }
1273 vm->next = *p;
1274 *p = vm;
1275 write_unlock(&vmlist_lock);
1276}
1277
1278static struct vm_struct *__get_vm_area_node(unsigned long size,
1279 unsigned long align, unsigned long flags, unsigned long start,
1280 unsigned long end, int node, gfp_t gfp_mask, void *caller)
1281{
1282 static struct vmap_area *va;
1283 struct vm_struct *area;
1284
1285 BUG_ON(in_interrupt());
1286 if (flags & VM_IOREMAP) {
1287 int bit = fls(size);
1288
1289 if (bit > IOREMAP_MAX_ORDER)
1290 bit = IOREMAP_MAX_ORDER;
1291 else if (bit < PAGE_SHIFT)
1292 bit = PAGE_SHIFT;
1293
1294 align = 1ul << bit;
1295 }
1296
1297 size = PAGE_ALIGN(size);
1298 if (unlikely(!size))
1299 return NULL;
1300
1301 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
1302 if (unlikely(!area))
1303 return NULL;
1304
1305 /*
1306 * We always allocate a guard page.
1307 */
1308 size += PAGE_SIZE;
1309
1310 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
1311 if (IS_ERR(va)) {
1312 kfree(area);
1313 return NULL;
1314 }
1315
1316 insert_vmalloc_vm(area, va, flags, caller);
1317 return area;
1318}
1319
1320struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
1321 unsigned long start, unsigned long end)
1322{
1323 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1324 __builtin_return_address(0));
1325}
1326EXPORT_SYMBOL_GPL(__get_vm_area);
1327
1328struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
1329 unsigned long start, unsigned long end,
1330 void *caller)
1331{
1332 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1333 caller);
1334}
1335
1336/**
1337 * get_vm_area - reserve a contiguous kernel virtual area
1338 * @size: size of the area
1339 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
1340 *
1341 * Search an area of @size in the kernel virtual mapping area,
1342 * and reserved it for out purposes. Returns the area descriptor
1343 * on success or %NULL on failure.
1344 */
1345struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
1346{
1347 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1348 -1, GFP_KERNEL, __builtin_return_address(0));
1349}
1350
1351struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
1352 void *caller)
1353{
1354 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1355 -1, GFP_KERNEL, caller);
1356}
1357
1358static struct vm_struct *find_vm_area(const void *addr)
1359{
1360 struct vmap_area *va;
1361
1362 va = find_vmap_area((unsigned long)addr);
1363 if (va && va->flags & VM_VM_AREA)
1364 return va->private;
1365
1366 return NULL;
1367}
1368
1369/**
1370 * remove_vm_area - find and remove a continuous kernel virtual area
1371 * @addr: base address
1372 *
1373 * Search for the kernel VM area starting at @addr, and remove it.
1374 * This function returns the found VM area, but using it is NOT safe
1375 * on SMP machines, except for its size or flags.
1376 */
1377struct vm_struct *remove_vm_area(const void *addr)
1378{
1379 struct vmap_area *va;
1380
1381 va = find_vmap_area((unsigned long)addr);
1382 if (va && va->flags & VM_VM_AREA) {
1383 struct vm_struct *vm = va->private;
1384 struct vm_struct *tmp, **p;
1385 /*
1386 * remove from list and disallow access to this vm_struct
1387 * before unmap. (address range confliction is maintained by
1388 * vmap.)
1389 */
1390 write_lock(&vmlist_lock);
1391 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
1392 ;
1393 *p = tmp->next;
1394 write_unlock(&vmlist_lock);
1395
1396 vmap_debug_free_range(va->va_start, va->va_end);
1397 free_unmap_vmap_area(va);
1398 vm->size -= PAGE_SIZE;
1399
1400 return vm;
1401 }
1402 return NULL;
1403}
1404
1405static void __vunmap(const void *addr, int deallocate_pages)
1406{
1407 struct vm_struct *area;
1408
1409 if (!addr)
1410 return;
1411
1412 if ((PAGE_SIZE-1) & (unsigned long)addr) {
1413 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
1414 return;
1415 }
1416
1417 area = remove_vm_area(addr);
1418 if (unlikely(!area)) {
1419 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
1420 addr);
1421 return;
1422 }
1423
1424 debug_check_no_locks_freed(addr, area->size);
1425 debug_check_no_obj_freed(addr, area->size);
1426
1427 if (deallocate_pages) {
1428 int i;
1429
1430 for (i = 0; i < area->nr_pages; i++) {
1431 struct page *page = area->pages[i];
1432
1433 BUG_ON(!page);
1434 __free_page(page);
1435 }
1436
1437 if (area->flags & VM_VPAGES)
1438 vfree(area->pages);
1439 else
1440 kfree(area->pages);
1441 }
1442
1443 kfree(area);
1444 return;
1445}
1446
1447/**
1448 * vfree - release memory allocated by vmalloc()
1449 * @addr: memory base address
1450 *
1451 * Free the virtually continuous memory area starting at @addr, as
1452 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
1453 * NULL, no operation is performed.
1454 *
1455 * Must not be called in interrupt context.
1456 */
1457void vfree(const void *addr)
1458{
1459 BUG_ON(in_interrupt());
1460
1461 kmemleak_free(addr);
1462
1463 __vunmap(addr, 1);
1464}
1465EXPORT_SYMBOL(vfree);
1466
1467/**
1468 * vunmap - release virtual mapping obtained by vmap()
1469 * @addr: memory base address
1470 *
1471 * Free the virtually contiguous memory area starting at @addr,
1472 * which was created from the page array passed to vmap().
1473 *
1474 * Must not be called in interrupt context.
1475 */
1476void vunmap(const void *addr)
1477{
1478 BUG_ON(in_interrupt());
1479 might_sleep();
1480 __vunmap(addr, 0);
1481}
1482EXPORT_SYMBOL(vunmap);
1483
1484/**
1485 * vmap - map an array of pages into virtually contiguous space
1486 * @pages: array of page pointers
1487 * @count: number of pages to map
1488 * @flags: vm_area->flags
1489 * @prot: page protection for the mapping
1490 *
1491 * Maps @count pages from @pages into contiguous kernel virtual
1492 * space.
1493 */
1494void *vmap(struct page **pages, unsigned int count,
1495 unsigned long flags, pgprot_t prot)
1496{
1497 struct vm_struct *area;
1498
1499 might_sleep();
1500
1501 if (count > totalram_pages)
1502 return NULL;
1503
1504 area = get_vm_area_caller((count << PAGE_SHIFT), flags,
1505 __builtin_return_address(0));
1506 if (!area)
1507 return NULL;
1508
1509 if (map_vm_area(area, prot, &pages)) {
1510 vunmap(area->addr);
1511 return NULL;
1512 }
1513
1514 return area->addr;
1515}
1516EXPORT_SYMBOL(vmap);
1517
1518static void *__vmalloc_node(unsigned long size, unsigned long align,
1519 gfp_t gfp_mask, pgprot_t prot,
1520 int node, void *caller);
1521static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1522 pgprot_t prot, int node, void *caller)
1523{
1524 const int order = 0;
1525 struct page **pages;
1526 unsigned int nr_pages, array_size, i;
1527 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
1528
1529 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
1530 array_size = (nr_pages * sizeof(struct page *));
1531
1532 area->nr_pages = nr_pages;
1533 /* Please note that the recursion is strictly bounded. */
1534 if (array_size > PAGE_SIZE) {
1535 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1536 PAGE_KERNEL, node, caller);
1537 area->flags |= VM_VPAGES;
1538 } else {
1539 pages = kmalloc_node(array_size, nested_gfp, node);
1540 }
1541 area->pages = pages;
1542 area->caller = caller;
1543 if (!area->pages) {
1544 remove_vm_area(area->addr);
1545 kfree(area);
1546 return NULL;
1547 }
1548
1549 for (i = 0; i < area->nr_pages; i++) {
1550 struct page *page;
1551 gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1552
1553 if (node < 0)
1554 page = alloc_page(tmp_mask);
1555 else
1556 page = alloc_pages_node(node, tmp_mask, order);
1557
1558 if (unlikely(!page)) {
1559 /* Successfully allocated i pages, free them in __vunmap() */
1560 area->nr_pages = i;
1561 goto fail;
1562 }
1563 area->pages[i] = page;
1564 }
1565
1566 if (map_vm_area(area, prot, &pages))
1567 goto fail;
1568 return area->addr;
1569
1570fail:
1571 warn_alloc_failed(gfp_mask, order, "vmalloc: allocation failure, "
1572 "allocated %ld of %ld bytes\n",
1573 (area->nr_pages*PAGE_SIZE), area->size);
1574 vfree(area->addr);
1575 return NULL;
1576}
1577
1578/**
1579 * __vmalloc_node_range - allocate virtually contiguous memory
1580 * @size: allocation size
1581 * @align: desired alignment
1582 * @start: vm area range start
1583 * @end: vm area range end
1584 * @gfp_mask: flags for the page level allocator
1585 * @prot: protection mask for the allocated pages
1586 * @node: node to use for allocation or -1
1587 * @caller: caller's return address
1588 *
1589 * Allocate enough pages to cover @size from the page level
1590 * allocator with @gfp_mask flags. Map them into contiguous
1591 * kernel virtual space, using a pagetable protection of @prot.
1592 */
1593void *__vmalloc_node_range(unsigned long size, unsigned long align,
1594 unsigned long start, unsigned long end, gfp_t gfp_mask,
1595 pgprot_t prot, int node, void *caller)
1596{
1597 struct vm_struct *area;
1598 void *addr;
1599 unsigned long real_size = size;
1600
1601 size = PAGE_ALIGN(size);
1602 if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1603 return NULL;
1604
1605 area = __get_vm_area_node(size, align, VM_ALLOC, start, end, node,
1606 gfp_mask, caller);
1607
1608 if (!area)
1609 return NULL;
1610
1611 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);
1612
1613 /*
1614 * A ref_count = 3 is needed because the vm_struct and vmap_area
1615 * structures allocated in the __get_vm_area_node() function contain
1616 * references to the virtual address of the vmalloc'ed block.
1617 */
1618 kmemleak_alloc(addr, real_size, 3, gfp_mask);
1619
1620 return addr;
1621}
1622
1623/**
1624 * __vmalloc_node - allocate virtually contiguous memory
1625 * @size: allocation size
1626 * @align: desired alignment
1627 * @gfp_mask: flags for the page level allocator
1628 * @prot: protection mask for the allocated pages
1629 * @node: node to use for allocation or -1
1630 * @caller: caller's return address
1631 *
1632 * Allocate enough pages to cover @size from the page level
1633 * allocator with @gfp_mask flags. Map them into contiguous
1634 * kernel virtual space, using a pagetable protection of @prot.
1635 */
1636static void *__vmalloc_node(unsigned long size, unsigned long align,
1637 gfp_t gfp_mask, pgprot_t prot,
1638 int node, void *caller)
1639{
1640 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
1641 gfp_mask, prot, node, caller);
1642}
1643
1644void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
1645{
1646 return __vmalloc_node(size, 1, gfp_mask, prot, -1,
1647 __builtin_return_address(0));
1648}
1649EXPORT_SYMBOL(__vmalloc);
1650
1651static inline void *__vmalloc_node_flags(unsigned long size,
1652 int node, gfp_t flags)
1653{
1654 return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
1655 node, __builtin_return_address(0));
1656}
1657
1658/**
1659 * vmalloc - allocate virtually contiguous memory
1660 * @size: allocation size
1661 * Allocate enough pages to cover @size from the page level
1662 * allocator and map them into contiguous kernel virtual space.
1663 *
1664 * For tight control over page level allocator and protection flags
1665 * use __vmalloc() instead.
1666 */
1667void *vmalloc(unsigned long size)
1668{
1669 return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
1670}
1671EXPORT_SYMBOL(vmalloc);
1672
1673/**
1674 * vzalloc - allocate virtually contiguous memory with zero fill
1675 * @size: allocation size
1676 * Allocate enough pages to cover @size from the page level
1677 * allocator and map them into contiguous kernel virtual space.
1678 * The memory allocated is set to zero.
1679 *
1680 * For tight control over page level allocator and protection flags
1681 * use __vmalloc() instead.
1682 */
1683void *vzalloc(unsigned long size)
1684{
1685 return __vmalloc_node_flags(size, -1,
1686 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1687}
1688EXPORT_SYMBOL(vzalloc);
1689
1690/**
1691 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
1692 * @size: allocation size
1693 *
1694 * The resulting memory area is zeroed so it can be mapped to userspace
1695 * without leaking data.
1696 */
1697void *vmalloc_user(unsigned long size)
1698{
1699 struct vm_struct *area;
1700 void *ret;
1701
1702 ret = __vmalloc_node(size, SHMLBA,
1703 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
1704 PAGE_KERNEL, -1, __builtin_return_address(0));
1705 if (ret) {
1706 area = find_vm_area(ret);
1707 area->flags |= VM_USERMAP;
1708 }
1709 return ret;
1710}
1711EXPORT_SYMBOL(vmalloc_user);
1712
1713/**
1714 * vmalloc_node - allocate memory on a specific node
1715 * @size: allocation size
1716 * @node: numa node
1717 *
1718 * Allocate enough pages to cover @size from the page level
1719 * allocator and map them into contiguous kernel virtual space.
1720 *
1721 * For tight control over page level allocator and protection flags
1722 * use __vmalloc() instead.
1723 */
1724void *vmalloc_node(unsigned long size, int node)
1725{
1726 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1727 node, __builtin_return_address(0));
1728}
1729EXPORT_SYMBOL(vmalloc_node);
1730
1731/**
1732 * vzalloc_node - allocate memory on a specific node with zero fill
1733 * @size: allocation size
1734 * @node: numa node
1735 *
1736 * Allocate enough pages to cover @size from the page level
1737 * allocator and map them into contiguous kernel virtual space.
1738 * The memory allocated is set to zero.
1739 *
1740 * For tight control over page level allocator and protection flags
1741 * use __vmalloc_node() instead.
1742 */
1743void *vzalloc_node(unsigned long size, int node)
1744{
1745 return __vmalloc_node_flags(size, node,
1746 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
1747}
1748EXPORT_SYMBOL(vzalloc_node);
1749
1750#ifndef PAGE_KERNEL_EXEC
1751# define PAGE_KERNEL_EXEC PAGE_KERNEL
1752#endif
1753
1754/**
1755 * vmalloc_exec - allocate virtually contiguous, executable memory
1756 * @size: allocation size
1757 *
1758 * Kernel-internal function to allocate enough pages to cover @size
1759 * the page level allocator and map them into contiguous and
1760 * executable kernel virtual space.
1761 *
1762 * For tight control over page level allocator and protection flags
1763 * use __vmalloc() instead.
1764 */
1765
1766void *vmalloc_exec(unsigned long size)
1767{
1768 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
1769 -1, __builtin_return_address(0));
1770}
1771
1772#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1773#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1774#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1775#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1776#else
1777#define GFP_VMALLOC32 GFP_KERNEL
1778#endif
1779
1780/**
1781 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
1782 * @size: allocation size
1783 *
1784 * Allocate enough 32bit PA addressable pages to cover @size from the
1785 * page level allocator and map them into contiguous kernel virtual space.
1786 */
1787void *vmalloc_32(unsigned long size)
1788{
1789 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
1790 -1, __builtin_return_address(0));
1791}
1792EXPORT_SYMBOL(vmalloc_32);
1793
1794/**
1795 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1796 * @size: allocation size
1797 *
1798 * The resulting memory area is 32bit addressable and zeroed so it can be
1799 * mapped to userspace without leaking data.
1800 */
1801void *vmalloc_32_user(unsigned long size)
1802{
1803 struct vm_struct *area;
1804 void *ret;
1805
1806 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
1807 -1, __builtin_return_address(0));
1808 if (ret) {
1809 area = find_vm_area(ret);
1810 area->flags |= VM_USERMAP;
1811 }
1812 return ret;
1813}
1814EXPORT_SYMBOL(vmalloc_32_user);
1815
1816/*
1817 * small helper routine , copy contents to buf from addr.
1818 * If the page is not present, fill zero.
1819 */
1820
1821static int aligned_vread(char *buf, char *addr, unsigned long count)
1822{
1823 struct page *p;
1824 int copied = 0;
1825
1826 while (count) {
1827 unsigned long offset, length;
1828
1829 offset = (unsigned long)addr & ~PAGE_MASK;
1830 length = PAGE_SIZE - offset;
1831 if (length > count)
1832 length = count;
1833 p = vmalloc_to_page(addr);
1834 /*
1835 * To do safe access to this _mapped_ area, we need
1836 * lock. But adding lock here means that we need to add
1837 * overhead of vmalloc()/vfree() calles for this _debug_
1838 * interface, rarely used. Instead of that, we'll use
1839 * kmap() and get small overhead in this access function.
1840 */
1841 if (p) {
1842 /*
1843 * we can expect USER0 is not used (see vread/vwrite's
1844 * function description)
1845 */
1846 void *map = kmap_atomic(p, KM_USER0);
1847 memcpy(buf, map + offset, length);
1848 kunmap_atomic(map, KM_USER0);
1849 } else
1850 memset(buf, 0, length);
1851
1852 addr += length;
1853 buf += length;
1854 copied += length;
1855 count -= length;
1856 }
1857 return copied;
1858}
1859
1860static int aligned_vwrite(char *buf, char *addr, unsigned long count)
1861{
1862 struct page *p;
1863 int copied = 0;
1864
1865 while (count) {
1866 unsigned long offset, length;
1867
1868 offset = (unsigned long)addr & ~PAGE_MASK;
1869 length = PAGE_SIZE - offset;
1870 if (length > count)
1871 length = count;
1872 p = vmalloc_to_page(addr);
1873 /*
1874 * To do safe access to this _mapped_ area, we need
1875 * lock. But adding lock here means that we need to add
1876 * overhead of vmalloc()/vfree() calles for this _debug_
1877 * interface, rarely used. Instead of that, we'll use
1878 * kmap() and get small overhead in this access function.
1879 */
1880 if (p) {
1881 /*
1882 * we can expect USER0 is not used (see vread/vwrite's
1883 * function description)
1884 */
1885 void *map = kmap_atomic(p, KM_USER0);
1886 memcpy(map + offset, buf, length);
1887 kunmap_atomic(map, KM_USER0);
1888 }
1889 addr += length;
1890 buf += length;
1891 copied += length;
1892 count -= length;
1893 }
1894 return copied;
1895}
1896
1897/**
1898 * vread() - read vmalloc area in a safe way.
1899 * @buf: buffer for reading data
1900 * @addr: vm address.
1901 * @count: number of bytes to be read.
1902 *
1903 * Returns # of bytes which addr and buf should be increased.
1904 * (same number to @count). Returns 0 if [addr...addr+count) doesn't
1905 * includes any intersect with alive vmalloc area.
1906 *
1907 * This function checks that addr is a valid vmalloc'ed area, and
1908 * copy data from that area to a given buffer. If the given memory range
1909 * of [addr...addr+count) includes some valid address, data is copied to
1910 * proper area of @buf. If there are memory holes, they'll be zero-filled.
1911 * IOREMAP area is treated as memory hole and no copy is done.
1912 *
1913 * If [addr...addr+count) doesn't includes any intersects with alive
1914 * vm_struct area, returns 0.
1915 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1916 * the caller should guarantee KM_USER0 is not used.
1917 *
1918 * Note: In usual ops, vread() is never necessary because the caller
1919 * should know vmalloc() area is valid and can use memcpy().
1920 * This is for routines which have to access vmalloc area without
1921 * any informaion, as /dev/kmem.
1922 *
1923 */
1924
1925long vread(char *buf, char *addr, unsigned long count)
1926{
1927 struct vm_struct *tmp;
1928 char *vaddr, *buf_start = buf;
1929 unsigned long buflen = count;
1930 unsigned long n;
1931
1932 /* Don't allow overflow */
1933 if ((unsigned long) addr + count < count)
1934 count = -(unsigned long) addr;
1935
1936 read_lock(&vmlist_lock);
1937 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
1938 vaddr = (char *) tmp->addr;
1939 if (addr >= vaddr + tmp->size - PAGE_SIZE)
1940 continue;
1941 while (addr < vaddr) {
1942 if (count == 0)
1943 goto finished;
1944 *buf = '\0';
1945 buf++;
1946 addr++;
1947 count--;
1948 }
1949 n = vaddr + tmp->size - PAGE_SIZE - addr;
1950 if (n > count)
1951 n = count;
1952 if (!(tmp->flags & VM_IOREMAP))
1953 aligned_vread(buf, addr, n);
1954 else /* IOREMAP area is treated as memory hole */
1955 memset(buf, 0, n);
1956 buf += n;
1957 addr += n;
1958 count -= n;
1959 }
1960finished:
1961 read_unlock(&vmlist_lock);
1962
1963 if (buf == buf_start)
1964 return 0;
1965 /* zero-fill memory holes */
1966 if (buf != buf_start + buflen)
1967 memset(buf, 0, buflen - (buf - buf_start));
1968
1969 return buflen;
1970}
1971
1972/**
1973 * vwrite() - write vmalloc area in a safe way.
1974 * @buf: buffer for source data
1975 * @addr: vm address.
1976 * @count: number of bytes to be read.
1977 *
1978 * Returns # of bytes which addr and buf should be incresed.
1979 * (same number to @count).
1980 * If [addr...addr+count) doesn't includes any intersect with valid
1981 * vmalloc area, returns 0.
1982 *
1983 * This function checks that addr is a valid vmalloc'ed area, and
1984 * copy data from a buffer to the given addr. If specified range of
1985 * [addr...addr+count) includes some valid address, data is copied from
1986 * proper area of @buf. If there are memory holes, no copy to hole.
1987 * IOREMAP area is treated as memory hole and no copy is done.
1988 *
1989 * If [addr...addr+count) doesn't includes any intersects with alive
1990 * vm_struct area, returns 0.
1991 * @buf should be kernel's buffer. Because this function uses KM_USER0,
1992 * the caller should guarantee KM_USER0 is not used.
1993 *
1994 * Note: In usual ops, vwrite() is never necessary because the caller
1995 * should know vmalloc() area is valid and can use memcpy().
1996 * This is for routines which have to access vmalloc area without
1997 * any informaion, as /dev/kmem.
1998 */
1999
2000long vwrite(char *buf, char *addr, unsigned long count)
2001{
2002 struct vm_struct *tmp;
2003 char *vaddr;
2004 unsigned long n, buflen;
2005 int copied = 0;
2006
2007 /* Don't allow overflow */
2008 if ((unsigned long) addr + count < count)
2009 count = -(unsigned long) addr;
2010 buflen = count;
2011
2012 read_lock(&vmlist_lock);
2013 for (tmp = vmlist; count && tmp; tmp = tmp->next) {
2014 vaddr = (char *) tmp->addr;
2015 if (addr >= vaddr + tmp->size - PAGE_SIZE)
2016 continue;
2017 while (addr < vaddr) {
2018 if (count == 0)
2019 goto finished;
2020 buf++;
2021 addr++;
2022 count--;
2023 }
2024 n = vaddr + tmp->size - PAGE_SIZE - addr;
2025 if (n > count)
2026 n = count;
2027 if (!(tmp->flags & VM_IOREMAP)) {
2028 aligned_vwrite(buf, addr, n);
2029 copied++;
2030 }
2031 buf += n;
2032 addr += n;
2033 count -= n;
2034 }
2035finished:
2036 read_unlock(&vmlist_lock);
2037 if (!copied)
2038 return 0;
2039 return buflen;
2040}
2041
2042/**
2043 * remap_vmalloc_range - map vmalloc pages to userspace
2044 * @vma: vma to cover (map full range of vma)
2045 * @addr: vmalloc memory
2046 * @pgoff: number of pages into addr before first page to map
2047 *
2048 * Returns: 0 for success, -Exxx on failure
2049 *
2050 * This function checks that addr is a valid vmalloc'ed area, and
2051 * that it is big enough to cover the vma. Will return failure if
2052 * that criteria isn't met.
2053 *
2054 * Similar to remap_pfn_range() (see mm/memory.c)
2055 */
2056int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
2057 unsigned long pgoff)
2058{
2059 struct vm_struct *area;
2060 unsigned long uaddr = vma->vm_start;
2061 unsigned long usize = vma->vm_end - vma->vm_start;
2062
2063 if ((PAGE_SIZE-1) & (unsigned long)addr)
2064 return -EINVAL;
2065
2066 area = find_vm_area(addr);
2067 if (!area)
2068 return -EINVAL;
2069
2070 if (!(area->flags & VM_USERMAP))
2071 return -EINVAL;
2072
2073 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
2074 return -EINVAL;
2075
2076 addr += pgoff << PAGE_SHIFT;
2077 do {
2078 struct page *page = vmalloc_to_page(addr);
2079 int ret;
2080
2081 ret = vm_insert_page(vma, uaddr, page);
2082 if (ret)
2083 return ret;
2084
2085 uaddr += PAGE_SIZE;
2086 addr += PAGE_SIZE;
2087 usize -= PAGE_SIZE;
2088 } while (usize > 0);
2089
2090 /* Prevent "things" like memory migration? VM_flags need a cleanup... */
2091 vma->vm_flags |= VM_RESERVED;
2092
2093 return 0;
2094}
2095EXPORT_SYMBOL(remap_vmalloc_range);
2096
2097/*
2098 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
2099 * have one.
2100 */
2101void __attribute__((weak)) vmalloc_sync_all(void)
2102{
2103}
2104
2105
2106static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2107{
2108 /* apply_to_page_range() does all the hard work. */
2109 return 0;
2110}
2111
2112/**
2113 * alloc_vm_area - allocate a range of kernel address space
2114 * @size: size of the area
2115 *
2116 * Returns: NULL on failure, vm_struct on success
2117 *
2118 * This function reserves a range of kernel address space, and
2119 * allocates pagetables to map that range. No actual mappings
2120 * are created. If the kernel address space is not shared
2121 * between processes, it syncs the pagetable across all
2122 * processes.
2123 */
2124struct vm_struct *alloc_vm_area(size_t size)
2125{
2126 struct vm_struct *area;
2127
2128 area = get_vm_area_caller(size, VM_IOREMAP,
2129 __builtin_return_address(0));
2130 if (area == NULL)
2131 return NULL;
2132
2133 /*
2134 * This ensures that page tables are constructed for this region
2135 * of kernel virtual address space and mapped into init_mm.
2136 */
2137 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2138 area->size, f, NULL)) {
2139 free_vm_area(area);
2140 return NULL;
2141 }
2142
2143 /*
2144 * If the allocated address space is passed to a hypercall
2145 * before being used then we cannot rely on a page fault to
2146 * trigger an update of the page tables. So sync all the page
2147 * tables here.
2148 */
2149 vmalloc_sync_all();
2150
2151 return area;
2152}
2153EXPORT_SYMBOL_GPL(alloc_vm_area);
2154
2155void free_vm_area(struct vm_struct *area)
2156{
2157 struct vm_struct *ret;
2158 ret = remove_vm_area(area->addr);
2159 BUG_ON(ret != area);
2160 kfree(area);
2161}
2162EXPORT_SYMBOL_GPL(free_vm_area);
2163
2164#ifdef CONFIG_SMP
2165static struct vmap_area *node_to_va(struct rb_node *n)
2166{
2167 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
2168}
2169
2170/**
2171 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
2172 * @end: target address
2173 * @pnext: out arg for the next vmap_area
2174 * @pprev: out arg for the previous vmap_area
2175 *
2176 * Returns: %true if either or both of next and prev are found,
2177 * %false if no vmap_area exists
2178 *
2179 * Find vmap_areas end addresses of which enclose @end. ie. if not
2180 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
2181 */
2182static bool pvm_find_next_prev(unsigned long end,
2183 struct vmap_area **pnext,
2184 struct vmap_area **pprev)
2185{
2186 struct rb_node *n = vmap_area_root.rb_node;
2187 struct vmap_area *va = NULL;
2188
2189 while (n) {
2190 va = rb_entry(n, struct vmap_area, rb_node);
2191 if (end < va->va_end)
2192 n = n->rb_left;
2193 else if (end > va->va_end)
2194 n = n->rb_right;
2195 else
2196 break;
2197 }
2198
2199 if (!va)
2200 return false;
2201
2202 if (va->va_end > end) {
2203 *pnext = va;
2204 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2205 } else {
2206 *pprev = va;
2207 *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
2208 }
2209 return true;
2210}
2211
2212/**
2213 * pvm_determine_end - find the highest aligned address between two vmap_areas
2214 * @pnext: in/out arg for the next vmap_area
2215 * @pprev: in/out arg for the previous vmap_area
2216 * @align: alignment
2217 *
2218 * Returns: determined end address
2219 *
2220 * Find the highest aligned address between *@pnext and *@pprev below
2221 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
2222 * down address is between the end addresses of the two vmap_areas.
2223 *
2224 * Please note that the address returned by this function may fall
2225 * inside *@pnext vmap_area. The caller is responsible for checking
2226 * that.
2227 */
2228static unsigned long pvm_determine_end(struct vmap_area **pnext,
2229 struct vmap_area **pprev,
2230 unsigned long align)
2231{
2232 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2233 unsigned long addr;
2234
2235 if (*pnext)
2236 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
2237 else
2238 addr = vmalloc_end;
2239
2240 while (*pprev && (*pprev)->va_end > addr) {
2241 *pnext = *pprev;
2242 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
2243 }
2244
2245 return addr;
2246}
2247
2248/**
2249 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
2250 * @offsets: array containing offset of each area
2251 * @sizes: array containing size of each area
2252 * @nr_vms: the number of areas to allocate
2253 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
2254 *
2255 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
2256 * vm_structs on success, %NULL on failure
2257 *
2258 * Percpu allocator wants to use congruent vm areas so that it can
2259 * maintain the offsets among percpu areas. This function allocates
2260 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
2261 * be scattered pretty far, distance between two areas easily going up
2262 * to gigabytes. To avoid interacting with regular vmallocs, these
2263 * areas are allocated from top.
2264 *
2265 * Despite its complicated look, this allocator is rather simple. It
2266 * does everything top-down and scans areas from the end looking for
2267 * matching slot. While scanning, if any of the areas overlaps with
2268 * existing vmap_area, the base address is pulled down to fit the
2269 * area. Scanning is repeated till all the areas fit and then all
2270 * necessary data structres are inserted and the result is returned.
2271 */
2272struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
2273 const size_t *sizes, int nr_vms,
2274 size_t align)
2275{
2276 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
2277 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
2278 struct vmap_area **vas, *prev, *next;
2279 struct vm_struct **vms;
2280 int area, area2, last_area, term_area;
2281 unsigned long base, start, end, last_end;
2282 bool purged = false;
2283
2284 /* verify parameters and allocate data structures */
2285 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
2286 for (last_area = 0, area = 0; area < nr_vms; area++) {
2287 start = offsets[area];
2288 end = start + sizes[area];
2289
2290 /* is everything aligned properly? */
2291 BUG_ON(!IS_ALIGNED(offsets[area], align));
2292 BUG_ON(!IS_ALIGNED(sizes[area], align));
2293
2294 /* detect the area with the highest address */
2295 if (start > offsets[last_area])
2296 last_area = area;
2297
2298 for (area2 = 0; area2 < nr_vms; area2++) {
2299 unsigned long start2 = offsets[area2];
2300 unsigned long end2 = start2 + sizes[area2];
2301
2302 if (area2 == area)
2303 continue;
2304
2305 BUG_ON(start2 >= start && start2 < end);
2306 BUG_ON(end2 <= end && end2 > start);
2307 }
2308 }
2309 last_end = offsets[last_area] + sizes[last_area];
2310
2311 if (vmalloc_end - vmalloc_start < last_end) {
2312 WARN_ON(true);
2313 return NULL;
2314 }
2315
2316 vms = kzalloc(sizeof(vms[0]) * nr_vms, GFP_KERNEL);
2317 vas = kzalloc(sizeof(vas[0]) * nr_vms, GFP_KERNEL);
2318 if (!vas || !vms)
2319 goto err_free;
2320
2321 for (area = 0; area < nr_vms; area++) {
2322 vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
2323 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2324 if (!vas[area] || !vms[area])
2325 goto err_free;
2326 }
2327retry:
2328 spin_lock(&vmap_area_lock);
2329
2330 /* start scanning - we scan from the top, begin with the last area */
2331 area = term_area = last_area;
2332 start = offsets[area];
2333 end = start + sizes[area];
2334
2335 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
2336 base = vmalloc_end - last_end;
2337 goto found;
2338 }
2339 base = pvm_determine_end(&next, &prev, align) - end;
2340
2341 while (true) {
2342 BUG_ON(next && next->va_end <= base + end);
2343 BUG_ON(prev && prev->va_end > base + end);
2344
2345 /*
2346 * base might have underflowed, add last_end before
2347 * comparing.
2348 */
2349 if (base + last_end < vmalloc_start + last_end) {
2350 spin_unlock(&vmap_area_lock);
2351 if (!purged) {
2352 purge_vmap_area_lazy();
2353 purged = true;
2354 goto retry;
2355 }
2356 goto err_free;
2357 }
2358
2359 /*
2360 * If next overlaps, move base downwards so that it's
2361 * right below next and then recheck.
2362 */
2363 if (next && next->va_start < base + end) {
2364 base = pvm_determine_end(&next, &prev, align) - end;
2365 term_area = area;
2366 continue;
2367 }
2368
2369 /*
2370 * If prev overlaps, shift down next and prev and move
2371 * base so that it's right below new next and then
2372 * recheck.
2373 */
2374 if (prev && prev->va_end > base + start) {
2375 next = prev;
2376 prev = node_to_va(rb_prev(&next->rb_node));
2377 base = pvm_determine_end(&next, &prev, align) - end;
2378 term_area = area;
2379 continue;
2380 }
2381
2382 /*
2383 * This area fits, move on to the previous one. If
2384 * the previous one is the terminal one, we're done.
2385 */
2386 area = (area + nr_vms - 1) % nr_vms;
2387 if (area == term_area)
2388 break;
2389 start = offsets[area];
2390 end = start + sizes[area];
2391 pvm_find_next_prev(base + end, &next, &prev);
2392 }
2393found:
2394 /* we've found a fitting base, insert all va's */
2395 for (area = 0; area < nr_vms; area++) {
2396 struct vmap_area *va = vas[area];
2397
2398 va->va_start = base + offsets[area];
2399 va->va_end = va->va_start + sizes[area];
2400 __insert_vmap_area(va);
2401 }
2402
2403 vmap_area_pcpu_hole = base + offsets[last_area];
2404
2405 spin_unlock(&vmap_area_lock);
2406
2407 /* insert all vm's */
2408 for (area = 0; area < nr_vms; area++)
2409 insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
2410 pcpu_get_vm_areas);
2411
2412 kfree(vas);
2413 return vms;
2414
2415err_free:
2416 for (area = 0; area < nr_vms; area++) {
2417 if (vas)
2418 kfree(vas[area]);
2419 if (vms)
2420 kfree(vms[area]);
2421 }
2422 kfree(vas);
2423 kfree(vms);
2424 return NULL;
2425}
2426
2427/**
2428 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
2429 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
2430 * @nr_vms: the number of allocated areas
2431 *
2432 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
2433 */
2434void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
2435{
2436 int i;
2437
2438 for (i = 0; i < nr_vms; i++)
2439 free_vm_area(vms[i]);
2440 kfree(vms);
2441}
2442#endif /* CONFIG_SMP */
2443
2444#ifdef CONFIG_PROC_FS
2445static void *s_start(struct seq_file *m, loff_t *pos)
2446 __acquires(&vmlist_lock)
2447{
2448 loff_t n = *pos;
2449 struct vm_struct *v;
2450
2451 read_lock(&vmlist_lock);
2452 v = vmlist;
2453 while (n > 0 && v) {
2454 n--;
2455 v = v->next;
2456 }
2457 if (!n)
2458 return v;
2459
2460 return NULL;
2461
2462}
2463
2464static void *s_next(struct seq_file *m, void *p, loff_t *pos)
2465{
2466 struct vm_struct *v = p;
2467
2468 ++*pos;
2469 return v->next;
2470}
2471
2472static void s_stop(struct seq_file *m, void *p)
2473 __releases(&vmlist_lock)
2474{
2475 read_unlock(&vmlist_lock);
2476}
2477
2478static void show_numa_info(struct seq_file *m, struct vm_struct *v)
2479{
2480 if (NUMA_BUILD) {
2481 unsigned int nr, *counters = m->private;
2482
2483 if (!counters)
2484 return;
2485
2486 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
2487
2488 for (nr = 0; nr < v->nr_pages; nr++)
2489 counters[page_to_nid(v->pages[nr])]++;
2490
2491 for_each_node_state(nr, N_HIGH_MEMORY)
2492 if (counters[nr])
2493 seq_printf(m, " N%u=%u", nr, counters[nr]);
2494 }
2495}
2496
2497static int s_show(struct seq_file *m, void *p)
2498{
2499 struct vm_struct *v = p;
2500
2501 seq_printf(m, "0x%p-0x%p %7ld",
2502 v->addr, v->addr + v->size, v->size);
2503
2504 if (v->caller)
2505 seq_printf(m, " %pS", v->caller);
2506
2507 if (v->nr_pages)
2508 seq_printf(m, " pages=%d", v->nr_pages);
2509
2510 if (v->phys_addr)
2511 seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2512
2513 if (v->flags & VM_IOREMAP)
2514 seq_printf(m, " ioremap");
2515
2516 if (v->flags & VM_ALLOC)
2517 seq_printf(m, " vmalloc");
2518
2519 if (v->flags & VM_MAP)
2520 seq_printf(m, " vmap");
2521
2522 if (v->flags & VM_USERMAP)
2523 seq_printf(m, " user");
2524
2525 if (v->flags & VM_VPAGES)
2526 seq_printf(m, " vpages");
2527
2528 show_numa_info(m, v);
2529 seq_putc(m, '\n');
2530 return 0;
2531}
2532
2533static const struct seq_operations vmalloc_op = {
2534 .start = s_start,
2535 .next = s_next,
2536 .stop = s_stop,
2537 .show = s_show,
2538};
2539
2540static int vmalloc_open(struct inode *inode, struct file *file)
2541{
2542 unsigned int *ptr = NULL;
2543 int ret;
2544
2545 if (NUMA_BUILD) {
2546 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2547 if (ptr == NULL)
2548 return -ENOMEM;
2549 }
2550 ret = seq_open(file, &vmalloc_op);
2551 if (!ret) {
2552 struct seq_file *m = file->private_data;
2553 m->private = ptr;
2554 } else
2555 kfree(ptr);
2556 return ret;
2557}
2558
2559static const struct file_operations proc_vmalloc_operations = {
2560 .open = vmalloc_open,
2561 .read = seq_read,
2562 .llseek = seq_lseek,
2563 .release = seq_release_private,
2564};
2565
2566static int __init proc_vmalloc_init(void)
2567{
2568 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
2569 return 0;
2570}
2571module_init(proc_vmalloc_init);
2572#endif
2573
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 1993 Linus Torvalds
4 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
5 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
6 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
7 * Numa awareness, Christoph Lameter, SGI, June 2005
8 * Improving global KVA allocator, Uladzislau Rezki, Sony, May 2019
9 */
10
11#include <linux/vmalloc.h>
12#include <linux/mm.h>
13#include <linux/module.h>
14#include <linux/highmem.h>
15#include <linux/sched/signal.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/interrupt.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/set_memory.h>
22#include <linux/debugobjects.h>
23#include <linux/kallsyms.h>
24#include <linux/list.h>
25#include <linux/notifier.h>
26#include <linux/rbtree.h>
27#include <linux/xarray.h>
28#include <linux/io.h>
29#include <linux/rcupdate.h>
30#include <linux/pfn.h>
31#include <linux/kmemleak.h>
32#include <linux/atomic.h>
33#include <linux/compiler.h>
34#include <linux/llist.h>
35#include <linux/bitops.h>
36#include <linux/rbtree_augmented.h>
37#include <linux/overflow.h>
38#include <linux/pgtable.h>
39#include <linux/uaccess.h>
40#include <linux/hugetlb.h>
41#include <asm/tlbflush.h>
42#include <asm/shmparam.h>
43
44#include "internal.h"
45#include "pgalloc-track.h"
46
47#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
48static bool __ro_after_init vmap_allow_huge = true;
49
50static int __init set_nohugevmalloc(char *str)
51{
52 vmap_allow_huge = false;
53 return 0;
54}
55early_param("nohugevmalloc", set_nohugevmalloc);
56#else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
57static const bool vmap_allow_huge = false;
58#endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
59
60bool is_vmalloc_addr(const void *x)
61{
62 unsigned long addr = (unsigned long)x;
63
64 return addr >= VMALLOC_START && addr < VMALLOC_END;
65}
66EXPORT_SYMBOL(is_vmalloc_addr);
67
68struct vfree_deferred {
69 struct llist_head list;
70 struct work_struct wq;
71};
72static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
73
74static void __vunmap(const void *, int);
75
76static void free_work(struct work_struct *w)
77{
78 struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
79 struct llist_node *t, *llnode;
80
81 llist_for_each_safe(llnode, t, llist_del_all(&p->list))
82 __vunmap((void *)llnode, 1);
83}
84
85/*** Page table manipulation functions ***/
86static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
87 phys_addr_t phys_addr, pgprot_t prot,
88 unsigned int max_page_shift, pgtbl_mod_mask *mask)
89{
90 pte_t *pte;
91 u64 pfn;
92 unsigned long size = PAGE_SIZE;
93
94 pfn = phys_addr >> PAGE_SHIFT;
95 pte = pte_alloc_kernel_track(pmd, addr, mask);
96 if (!pte)
97 return -ENOMEM;
98 do {
99 BUG_ON(!pte_none(*pte));
100
101#ifdef CONFIG_HUGETLB_PAGE
102 size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
103 if (size != PAGE_SIZE) {
104 pte_t entry = pfn_pte(pfn, prot);
105
106 entry = pte_mkhuge(entry);
107 entry = arch_make_huge_pte(entry, ilog2(size), 0);
108 set_huge_pte_at(&init_mm, addr, pte, entry);
109 pfn += PFN_DOWN(size);
110 continue;
111 }
112#endif
113 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
114 pfn++;
115 } while (pte += PFN_DOWN(size), addr += size, addr != end);
116 *mask |= PGTBL_PTE_MODIFIED;
117 return 0;
118}
119
120static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
121 phys_addr_t phys_addr, pgprot_t prot,
122 unsigned int max_page_shift)
123{
124 if (max_page_shift < PMD_SHIFT)
125 return 0;
126
127 if (!arch_vmap_pmd_supported(prot))
128 return 0;
129
130 if ((end - addr) != PMD_SIZE)
131 return 0;
132
133 if (!IS_ALIGNED(addr, PMD_SIZE))
134 return 0;
135
136 if (!IS_ALIGNED(phys_addr, PMD_SIZE))
137 return 0;
138
139 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
140 return 0;
141
142 return pmd_set_huge(pmd, phys_addr, prot);
143}
144
145static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
146 phys_addr_t phys_addr, pgprot_t prot,
147 unsigned int max_page_shift, pgtbl_mod_mask *mask)
148{
149 pmd_t *pmd;
150 unsigned long next;
151
152 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
153 if (!pmd)
154 return -ENOMEM;
155 do {
156 next = pmd_addr_end(addr, end);
157
158 if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot,
159 max_page_shift)) {
160 *mask |= PGTBL_PMD_MODIFIED;
161 continue;
162 }
163
164 if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask))
165 return -ENOMEM;
166 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
167 return 0;
168}
169
170static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
171 phys_addr_t phys_addr, pgprot_t prot,
172 unsigned int max_page_shift)
173{
174 if (max_page_shift < PUD_SHIFT)
175 return 0;
176
177 if (!arch_vmap_pud_supported(prot))
178 return 0;
179
180 if ((end - addr) != PUD_SIZE)
181 return 0;
182
183 if (!IS_ALIGNED(addr, PUD_SIZE))
184 return 0;
185
186 if (!IS_ALIGNED(phys_addr, PUD_SIZE))
187 return 0;
188
189 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
190 return 0;
191
192 return pud_set_huge(pud, phys_addr, prot);
193}
194
195static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
196 phys_addr_t phys_addr, pgprot_t prot,
197 unsigned int max_page_shift, pgtbl_mod_mask *mask)
198{
199 pud_t *pud;
200 unsigned long next;
201
202 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
203 if (!pud)
204 return -ENOMEM;
205 do {
206 next = pud_addr_end(addr, end);
207
208 if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot,
209 max_page_shift)) {
210 *mask |= PGTBL_PUD_MODIFIED;
211 continue;
212 }
213
214 if (vmap_pmd_range(pud, addr, next, phys_addr, prot,
215 max_page_shift, mask))
216 return -ENOMEM;
217 } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
218 return 0;
219}
220
221static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
222 phys_addr_t phys_addr, pgprot_t prot,
223 unsigned int max_page_shift)
224{
225 if (max_page_shift < P4D_SHIFT)
226 return 0;
227
228 if (!arch_vmap_p4d_supported(prot))
229 return 0;
230
231 if ((end - addr) != P4D_SIZE)
232 return 0;
233
234 if (!IS_ALIGNED(addr, P4D_SIZE))
235 return 0;
236
237 if (!IS_ALIGNED(phys_addr, P4D_SIZE))
238 return 0;
239
240 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
241 return 0;
242
243 return p4d_set_huge(p4d, phys_addr, prot);
244}
245
246static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
247 phys_addr_t phys_addr, pgprot_t prot,
248 unsigned int max_page_shift, pgtbl_mod_mask *mask)
249{
250 p4d_t *p4d;
251 unsigned long next;
252
253 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
254 if (!p4d)
255 return -ENOMEM;
256 do {
257 next = p4d_addr_end(addr, end);
258
259 if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot,
260 max_page_shift)) {
261 *mask |= PGTBL_P4D_MODIFIED;
262 continue;
263 }
264
265 if (vmap_pud_range(p4d, addr, next, phys_addr, prot,
266 max_page_shift, mask))
267 return -ENOMEM;
268 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
269 return 0;
270}
271
272static int vmap_range_noflush(unsigned long addr, unsigned long end,
273 phys_addr_t phys_addr, pgprot_t prot,
274 unsigned int max_page_shift)
275{
276 pgd_t *pgd;
277 unsigned long start;
278 unsigned long next;
279 int err;
280 pgtbl_mod_mask mask = 0;
281
282 might_sleep();
283 BUG_ON(addr >= end);
284
285 start = addr;
286 pgd = pgd_offset_k(addr);
287 do {
288 next = pgd_addr_end(addr, end);
289 err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
290 max_page_shift, &mask);
291 if (err)
292 break;
293 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
294
295 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
296 arch_sync_kernel_mappings(start, end);
297
298 return err;
299}
300
301int vmap_range(unsigned long addr, unsigned long end,
302 phys_addr_t phys_addr, pgprot_t prot,
303 unsigned int max_page_shift)
304{
305 int err;
306
307 err = vmap_range_noflush(addr, end, phys_addr, prot, max_page_shift);
308 flush_cache_vmap(addr, end);
309
310 return err;
311}
312
313static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
314 pgtbl_mod_mask *mask)
315{
316 pte_t *pte;
317
318 pte = pte_offset_kernel(pmd, addr);
319 do {
320 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
321 WARN_ON(!pte_none(ptent) && !pte_present(ptent));
322 } while (pte++, addr += PAGE_SIZE, addr != end);
323 *mask |= PGTBL_PTE_MODIFIED;
324}
325
326static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
327 pgtbl_mod_mask *mask)
328{
329 pmd_t *pmd;
330 unsigned long next;
331 int cleared;
332
333 pmd = pmd_offset(pud, addr);
334 do {
335 next = pmd_addr_end(addr, end);
336
337 cleared = pmd_clear_huge(pmd);
338 if (cleared || pmd_bad(*pmd))
339 *mask |= PGTBL_PMD_MODIFIED;
340
341 if (cleared)
342 continue;
343 if (pmd_none_or_clear_bad(pmd))
344 continue;
345 vunmap_pte_range(pmd, addr, next, mask);
346
347 cond_resched();
348 } while (pmd++, addr = next, addr != end);
349}
350
351static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
352 pgtbl_mod_mask *mask)
353{
354 pud_t *pud;
355 unsigned long next;
356 int cleared;
357
358 pud = pud_offset(p4d, addr);
359 do {
360 next = pud_addr_end(addr, end);
361
362 cleared = pud_clear_huge(pud);
363 if (cleared || pud_bad(*pud))
364 *mask |= PGTBL_PUD_MODIFIED;
365
366 if (cleared)
367 continue;
368 if (pud_none_or_clear_bad(pud))
369 continue;
370 vunmap_pmd_range(pud, addr, next, mask);
371 } while (pud++, addr = next, addr != end);
372}
373
374static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
375 pgtbl_mod_mask *mask)
376{
377 p4d_t *p4d;
378 unsigned long next;
379 int cleared;
380
381 p4d = p4d_offset(pgd, addr);
382 do {
383 next = p4d_addr_end(addr, end);
384
385 cleared = p4d_clear_huge(p4d);
386 if (cleared || p4d_bad(*p4d))
387 *mask |= PGTBL_P4D_MODIFIED;
388
389 if (cleared)
390 continue;
391 if (p4d_none_or_clear_bad(p4d))
392 continue;
393 vunmap_pud_range(p4d, addr, next, mask);
394 } while (p4d++, addr = next, addr != end);
395}
396
397/*
398 * vunmap_range_noflush is similar to vunmap_range, but does not
399 * flush caches or TLBs.
400 *
401 * The caller is responsible for calling flush_cache_vmap() before calling
402 * this function, and flush_tlb_kernel_range after it has returned
403 * successfully (and before the addresses are expected to cause a page fault
404 * or be re-mapped for something else, if TLB flushes are being delayed or
405 * coalesced).
406 *
407 * This is an internal function only. Do not use outside mm/.
408 */
409void vunmap_range_noflush(unsigned long start, unsigned long end)
410{
411 unsigned long next;
412 pgd_t *pgd;
413 unsigned long addr = start;
414 pgtbl_mod_mask mask = 0;
415
416 BUG_ON(addr >= end);
417 pgd = pgd_offset_k(addr);
418 do {
419 next = pgd_addr_end(addr, end);
420 if (pgd_bad(*pgd))
421 mask |= PGTBL_PGD_MODIFIED;
422 if (pgd_none_or_clear_bad(pgd))
423 continue;
424 vunmap_p4d_range(pgd, addr, next, &mask);
425 } while (pgd++, addr = next, addr != end);
426
427 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
428 arch_sync_kernel_mappings(start, end);
429}
430
431/**
432 * vunmap_range - unmap kernel virtual addresses
433 * @addr: start of the VM area to unmap
434 * @end: end of the VM area to unmap (non-inclusive)
435 *
436 * Clears any present PTEs in the virtual address range, flushes TLBs and
437 * caches. Any subsequent access to the address before it has been re-mapped
438 * is a kernel bug.
439 */
440void vunmap_range(unsigned long addr, unsigned long end)
441{
442 flush_cache_vunmap(addr, end);
443 vunmap_range_noflush(addr, end);
444 flush_tlb_kernel_range(addr, end);
445}
446
447static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
448 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
449 pgtbl_mod_mask *mask)
450{
451 pte_t *pte;
452
453 /*
454 * nr is a running index into the array which helps higher level
455 * callers keep track of where we're up to.
456 */
457
458 pte = pte_alloc_kernel_track(pmd, addr, mask);
459 if (!pte)
460 return -ENOMEM;
461 do {
462 struct page *page = pages[*nr];
463
464 if (WARN_ON(!pte_none(*pte)))
465 return -EBUSY;
466 if (WARN_ON(!page))
467 return -ENOMEM;
468 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
469 (*nr)++;
470 } while (pte++, addr += PAGE_SIZE, addr != end);
471 *mask |= PGTBL_PTE_MODIFIED;
472 return 0;
473}
474
475static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr,
476 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
477 pgtbl_mod_mask *mask)
478{
479 pmd_t *pmd;
480 unsigned long next;
481
482 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
483 if (!pmd)
484 return -ENOMEM;
485 do {
486 next = pmd_addr_end(addr, end);
487 if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask))
488 return -ENOMEM;
489 } while (pmd++, addr = next, addr != end);
490 return 0;
491}
492
493static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr,
494 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
495 pgtbl_mod_mask *mask)
496{
497 pud_t *pud;
498 unsigned long next;
499
500 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
501 if (!pud)
502 return -ENOMEM;
503 do {
504 next = pud_addr_end(addr, end);
505 if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask))
506 return -ENOMEM;
507 } while (pud++, addr = next, addr != end);
508 return 0;
509}
510
511static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr,
512 unsigned long end, pgprot_t prot, struct page **pages, int *nr,
513 pgtbl_mod_mask *mask)
514{
515 p4d_t *p4d;
516 unsigned long next;
517
518 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
519 if (!p4d)
520 return -ENOMEM;
521 do {
522 next = p4d_addr_end(addr, end);
523 if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask))
524 return -ENOMEM;
525 } while (p4d++, addr = next, addr != end);
526 return 0;
527}
528
529static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
530 pgprot_t prot, struct page **pages)
531{
532 unsigned long start = addr;
533 pgd_t *pgd;
534 unsigned long next;
535 int err = 0;
536 int nr = 0;
537 pgtbl_mod_mask mask = 0;
538
539 BUG_ON(addr >= end);
540 pgd = pgd_offset_k(addr);
541 do {
542 next = pgd_addr_end(addr, end);
543 if (pgd_bad(*pgd))
544 mask |= PGTBL_PGD_MODIFIED;
545 err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
546 if (err)
547 return err;
548 } while (pgd++, addr = next, addr != end);
549
550 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
551 arch_sync_kernel_mappings(start, end);
552
553 return 0;
554}
555
556/*
557 * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
558 * flush caches.
559 *
560 * The caller is responsible for calling flush_cache_vmap() after this
561 * function returns successfully and before the addresses are accessed.
562 *
563 * This is an internal function only. Do not use outside mm/.
564 */
565int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
566 pgprot_t prot, struct page **pages, unsigned int page_shift)
567{
568 unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
569
570 WARN_ON(page_shift < PAGE_SHIFT);
571
572 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
573 page_shift == PAGE_SHIFT)
574 return vmap_small_pages_range_noflush(addr, end, prot, pages);
575
576 for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
577 int err;
578
579 err = vmap_range_noflush(addr, addr + (1UL << page_shift),
580 __pa(page_address(pages[i])), prot,
581 page_shift);
582 if (err)
583 return err;
584
585 addr += 1UL << page_shift;
586 }
587
588 return 0;
589}
590
591/**
592 * vmap_pages_range - map pages to a kernel virtual address
593 * @addr: start of the VM area to map
594 * @end: end of the VM area to map (non-inclusive)
595 * @prot: page protection flags to use
596 * @pages: pages to map (always PAGE_SIZE pages)
597 * @page_shift: maximum shift that the pages may be mapped with, @pages must
598 * be aligned and contiguous up to at least this shift.
599 *
600 * RETURNS:
601 * 0 on success, -errno on failure.
602 */
603static int vmap_pages_range(unsigned long addr, unsigned long end,
604 pgprot_t prot, struct page **pages, unsigned int page_shift)
605{
606 int err;
607
608 err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
609 flush_cache_vmap(addr, end);
610 return err;
611}
612
613int is_vmalloc_or_module_addr(const void *x)
614{
615 /*
616 * ARM, x86-64 and sparc64 put modules in a special place,
617 * and fall back on vmalloc() if that fails. Others
618 * just put it in the vmalloc space.
619 */
620#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
621 unsigned long addr = (unsigned long)x;
622 if (addr >= MODULES_VADDR && addr < MODULES_END)
623 return 1;
624#endif
625 return is_vmalloc_addr(x);
626}
627
628/*
629 * Walk a vmap address to the struct page it maps. Huge vmap mappings will
630 * return the tail page that corresponds to the base page address, which
631 * matches small vmap mappings.
632 */
633struct page *vmalloc_to_page(const void *vmalloc_addr)
634{
635 unsigned long addr = (unsigned long) vmalloc_addr;
636 struct page *page = NULL;
637 pgd_t *pgd = pgd_offset_k(addr);
638 p4d_t *p4d;
639 pud_t *pud;
640 pmd_t *pmd;
641 pte_t *ptep, pte;
642
643 /*
644 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
645 * architectures that do not vmalloc module space
646 */
647 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
648
649 if (pgd_none(*pgd))
650 return NULL;
651 if (WARN_ON_ONCE(pgd_leaf(*pgd)))
652 return NULL; /* XXX: no allowance for huge pgd */
653 if (WARN_ON_ONCE(pgd_bad(*pgd)))
654 return NULL;
655
656 p4d = p4d_offset(pgd, addr);
657 if (p4d_none(*p4d))
658 return NULL;
659 if (p4d_leaf(*p4d))
660 return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
661 if (WARN_ON_ONCE(p4d_bad(*p4d)))
662 return NULL;
663
664 pud = pud_offset(p4d, addr);
665 if (pud_none(*pud))
666 return NULL;
667 if (pud_leaf(*pud))
668 return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
669 if (WARN_ON_ONCE(pud_bad(*pud)))
670 return NULL;
671
672 pmd = pmd_offset(pud, addr);
673 if (pmd_none(*pmd))
674 return NULL;
675 if (pmd_leaf(*pmd))
676 return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
677 if (WARN_ON_ONCE(pmd_bad(*pmd)))
678 return NULL;
679
680 ptep = pte_offset_map(pmd, addr);
681 pte = *ptep;
682 if (pte_present(pte))
683 page = pte_page(pte);
684 pte_unmap(ptep);
685
686 return page;
687}
688EXPORT_SYMBOL(vmalloc_to_page);
689
690/*
691 * Map a vmalloc()-space virtual address to the physical page frame number.
692 */
693unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
694{
695 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
696}
697EXPORT_SYMBOL(vmalloc_to_pfn);
698
699
700/*** Global kva allocator ***/
701
702#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
703#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
704
705
706static DEFINE_SPINLOCK(vmap_area_lock);
707static DEFINE_SPINLOCK(free_vmap_area_lock);
708/* Export for kexec only */
709LIST_HEAD(vmap_area_list);
710static struct rb_root vmap_area_root = RB_ROOT;
711static bool vmap_initialized __read_mostly;
712
713static struct rb_root purge_vmap_area_root = RB_ROOT;
714static LIST_HEAD(purge_vmap_area_list);
715static DEFINE_SPINLOCK(purge_vmap_area_lock);
716
717/*
718 * This kmem_cache is used for vmap_area objects. Instead of
719 * allocating from slab we reuse an object from this cache to
720 * make things faster. Especially in "no edge" splitting of
721 * free block.
722 */
723static struct kmem_cache *vmap_area_cachep;
724
725/*
726 * This linked list is used in pair with free_vmap_area_root.
727 * It gives O(1) access to prev/next to perform fast coalescing.
728 */
729static LIST_HEAD(free_vmap_area_list);
730
731/*
732 * This augment red-black tree represents the free vmap space.
733 * All vmap_area objects in this tree are sorted by va->va_start
734 * address. It is used for allocation and merging when a vmap
735 * object is released.
736 *
737 * Each vmap_area node contains a maximum available free block
738 * of its sub-tree, right or left. Therefore it is possible to
739 * find a lowest match of free area.
740 */
741static struct rb_root free_vmap_area_root = RB_ROOT;
742
743/*
744 * Preload a CPU with one object for "no edge" split case. The
745 * aim is to get rid of allocations from the atomic context, thus
746 * to use more permissive allocation masks.
747 */
748static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
749
750static __always_inline unsigned long
751va_size(struct vmap_area *va)
752{
753 return (va->va_end - va->va_start);
754}
755
756static __always_inline unsigned long
757get_subtree_max_size(struct rb_node *node)
758{
759 struct vmap_area *va;
760
761 va = rb_entry_safe(node, struct vmap_area, rb_node);
762 return va ? va->subtree_max_size : 0;
763}
764
765/*
766 * Gets called when remove the node and rotate.
767 */
768static __always_inline unsigned long
769compute_subtree_max_size(struct vmap_area *va)
770{
771 return max3(va_size(va),
772 get_subtree_max_size(va->rb_node.rb_left),
773 get_subtree_max_size(va->rb_node.rb_right));
774}
775
776RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
777 struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
778
779static void purge_vmap_area_lazy(void);
780static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
781static unsigned long lazy_max_pages(void);
782
783static atomic_long_t nr_vmalloc_pages;
784
785unsigned long vmalloc_nr_pages(void)
786{
787 return atomic_long_read(&nr_vmalloc_pages);
788}
789
790static struct vmap_area *__find_vmap_area(unsigned long addr)
791{
792 struct rb_node *n = vmap_area_root.rb_node;
793
794 while (n) {
795 struct vmap_area *va;
796
797 va = rb_entry(n, struct vmap_area, rb_node);
798 if (addr < va->va_start)
799 n = n->rb_left;
800 else if (addr >= va->va_end)
801 n = n->rb_right;
802 else
803 return va;
804 }
805
806 return NULL;
807}
808
809/*
810 * This function returns back addresses of parent node
811 * and its left or right link for further processing.
812 *
813 * Otherwise NULL is returned. In that case all further
814 * steps regarding inserting of conflicting overlap range
815 * have to be declined and actually considered as a bug.
816 */
817static __always_inline struct rb_node **
818find_va_links(struct vmap_area *va,
819 struct rb_root *root, struct rb_node *from,
820 struct rb_node **parent)
821{
822 struct vmap_area *tmp_va;
823 struct rb_node **link;
824
825 if (root) {
826 link = &root->rb_node;
827 if (unlikely(!*link)) {
828 *parent = NULL;
829 return link;
830 }
831 } else {
832 link = &from;
833 }
834
835 /*
836 * Go to the bottom of the tree. When we hit the last point
837 * we end up with parent rb_node and correct direction, i name
838 * it link, where the new va->rb_node will be attached to.
839 */
840 do {
841 tmp_va = rb_entry(*link, struct vmap_area, rb_node);
842
843 /*
844 * During the traversal we also do some sanity check.
845 * Trigger the BUG() if there are sides(left/right)
846 * or full overlaps.
847 */
848 if (va->va_start < tmp_va->va_end &&
849 va->va_end <= tmp_va->va_start)
850 link = &(*link)->rb_left;
851 else if (va->va_end > tmp_va->va_start &&
852 va->va_start >= tmp_va->va_end)
853 link = &(*link)->rb_right;
854 else {
855 WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
856 va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
857
858 return NULL;
859 }
860 } while (*link);
861
862 *parent = &tmp_va->rb_node;
863 return link;
864}
865
866static __always_inline struct list_head *
867get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
868{
869 struct list_head *list;
870
871 if (unlikely(!parent))
872 /*
873 * The red-black tree where we try to find VA neighbors
874 * before merging or inserting is empty, i.e. it means
875 * there is no free vmap space. Normally it does not
876 * happen but we handle this case anyway.
877 */
878 return NULL;
879
880 list = &rb_entry(parent, struct vmap_area, rb_node)->list;
881 return (&parent->rb_right == link ? list->next : list);
882}
883
884static __always_inline void
885link_va(struct vmap_area *va, struct rb_root *root,
886 struct rb_node *parent, struct rb_node **link, struct list_head *head)
887{
888 /*
889 * VA is still not in the list, but we can
890 * identify its future previous list_head node.
891 */
892 if (likely(parent)) {
893 head = &rb_entry(parent, struct vmap_area, rb_node)->list;
894 if (&parent->rb_right != link)
895 head = head->prev;
896 }
897
898 /* Insert to the rb-tree */
899 rb_link_node(&va->rb_node, parent, link);
900 if (root == &free_vmap_area_root) {
901 /*
902 * Some explanation here. Just perform simple insertion
903 * to the tree. We do not set va->subtree_max_size to
904 * its current size before calling rb_insert_augmented().
905 * It is because of we populate the tree from the bottom
906 * to parent levels when the node _is_ in the tree.
907 *
908 * Therefore we set subtree_max_size to zero after insertion,
909 * to let __augment_tree_propagate_from() puts everything to
910 * the correct order later on.
911 */
912 rb_insert_augmented(&va->rb_node,
913 root, &free_vmap_area_rb_augment_cb);
914 va->subtree_max_size = 0;
915 } else {
916 rb_insert_color(&va->rb_node, root);
917 }
918
919 /* Address-sort this list */
920 list_add(&va->list, head);
921}
922
923static __always_inline void
924unlink_va(struct vmap_area *va, struct rb_root *root)
925{
926 if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
927 return;
928
929 if (root == &free_vmap_area_root)
930 rb_erase_augmented(&va->rb_node,
931 root, &free_vmap_area_rb_augment_cb);
932 else
933 rb_erase(&va->rb_node, root);
934
935 list_del(&va->list);
936 RB_CLEAR_NODE(&va->rb_node);
937}
938
939#if DEBUG_AUGMENT_PROPAGATE_CHECK
940static void
941augment_tree_propagate_check(void)
942{
943 struct vmap_area *va;
944 unsigned long computed_size;
945
946 list_for_each_entry(va, &free_vmap_area_list, list) {
947 computed_size = compute_subtree_max_size(va);
948 if (computed_size != va->subtree_max_size)
949 pr_emerg("tree is corrupted: %lu, %lu\n",
950 va_size(va), va->subtree_max_size);
951 }
952}
953#endif
954
955/*
956 * This function populates subtree_max_size from bottom to upper
957 * levels starting from VA point. The propagation must be done
958 * when VA size is modified by changing its va_start/va_end. Or
959 * in case of newly inserting of VA to the tree.
960 *
961 * It means that __augment_tree_propagate_from() must be called:
962 * - After VA has been inserted to the tree(free path);
963 * - After VA has been shrunk(allocation path);
964 * - After VA has been increased(merging path).
965 *
966 * Please note that, it does not mean that upper parent nodes
967 * and their subtree_max_size are recalculated all the time up
968 * to the root node.
969 *
970 * 4--8
971 * /\
972 * / \
973 * / \
974 * 2--2 8--8
975 *
976 * For example if we modify the node 4, shrinking it to 2, then
977 * no any modification is required. If we shrink the node 2 to 1
978 * its subtree_max_size is updated only, and set to 1. If we shrink
979 * the node 8 to 6, then its subtree_max_size is set to 6 and parent
980 * node becomes 4--6.
981 */
982static __always_inline void
983augment_tree_propagate_from(struct vmap_area *va)
984{
985 /*
986 * Populate the tree from bottom towards the root until
987 * the calculated maximum available size of checked node
988 * is equal to its current one.
989 */
990 free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL);
991
992#if DEBUG_AUGMENT_PROPAGATE_CHECK
993 augment_tree_propagate_check();
994#endif
995}
996
997static void
998insert_vmap_area(struct vmap_area *va,
999 struct rb_root *root, struct list_head *head)
1000{
1001 struct rb_node **link;
1002 struct rb_node *parent;
1003
1004 link = find_va_links(va, root, NULL, &parent);
1005 if (link)
1006 link_va(va, root, parent, link, head);
1007}
1008
1009static void
1010insert_vmap_area_augment(struct vmap_area *va,
1011 struct rb_node *from, struct rb_root *root,
1012 struct list_head *head)
1013{
1014 struct rb_node **link;
1015 struct rb_node *parent;
1016
1017 if (from)
1018 link = find_va_links(va, NULL, from, &parent);
1019 else
1020 link = find_va_links(va, root, NULL, &parent);
1021
1022 if (link) {
1023 link_va(va, root, parent, link, head);
1024 augment_tree_propagate_from(va);
1025 }
1026}
1027
1028/*
1029 * Merge de-allocated chunk of VA memory with previous
1030 * and next free blocks. If coalesce is not done a new
1031 * free area is inserted. If VA has been merged, it is
1032 * freed.
1033 *
1034 * Please note, it can return NULL in case of overlap
1035 * ranges, followed by WARN() report. Despite it is a
1036 * buggy behaviour, a system can be alive and keep
1037 * ongoing.
1038 */
1039static __always_inline struct vmap_area *
1040merge_or_add_vmap_area(struct vmap_area *va,
1041 struct rb_root *root, struct list_head *head)
1042{
1043 struct vmap_area *sibling;
1044 struct list_head *next;
1045 struct rb_node **link;
1046 struct rb_node *parent;
1047 bool merged = false;
1048
1049 /*
1050 * Find a place in the tree where VA potentially will be
1051 * inserted, unless it is merged with its sibling/siblings.
1052 */
1053 link = find_va_links(va, root, NULL, &parent);
1054 if (!link)
1055 return NULL;
1056
1057 /*
1058 * Get next node of VA to check if merging can be done.
1059 */
1060 next = get_va_next_sibling(parent, link);
1061 if (unlikely(next == NULL))
1062 goto insert;
1063
1064 /*
1065 * start end
1066 * | |
1067 * |<------VA------>|<-----Next----->|
1068 * | |
1069 * start end
1070 */
1071 if (next != head) {
1072 sibling = list_entry(next, struct vmap_area, list);
1073 if (sibling->va_start == va->va_end) {
1074 sibling->va_start = va->va_start;
1075
1076 /* Free vmap_area object. */
1077 kmem_cache_free(vmap_area_cachep, va);
1078
1079 /* Point to the new merged area. */
1080 va = sibling;
1081 merged = true;
1082 }
1083 }
1084
1085 /*
1086 * start end
1087 * | |
1088 * |<-----Prev----->|<------VA------>|
1089 * | |
1090 * start end
1091 */
1092 if (next->prev != head) {
1093 sibling = list_entry(next->prev, struct vmap_area, list);
1094 if (sibling->va_end == va->va_start) {
1095 /*
1096 * If both neighbors are coalesced, it is important
1097 * to unlink the "next" node first, followed by merging
1098 * with "previous" one. Otherwise the tree might not be
1099 * fully populated if a sibling's augmented value is
1100 * "normalized" because of rotation operations.
1101 */
1102 if (merged)
1103 unlink_va(va, root);
1104
1105 sibling->va_end = va->va_end;
1106
1107 /* Free vmap_area object. */
1108 kmem_cache_free(vmap_area_cachep, va);
1109
1110 /* Point to the new merged area. */
1111 va = sibling;
1112 merged = true;
1113 }
1114 }
1115
1116insert:
1117 if (!merged)
1118 link_va(va, root, parent, link, head);
1119
1120 return va;
1121}
1122
1123static __always_inline struct vmap_area *
1124merge_or_add_vmap_area_augment(struct vmap_area *va,
1125 struct rb_root *root, struct list_head *head)
1126{
1127 va = merge_or_add_vmap_area(va, root, head);
1128 if (va)
1129 augment_tree_propagate_from(va);
1130
1131 return va;
1132}
1133
1134static __always_inline bool
1135is_within_this_va(struct vmap_area *va, unsigned long size,
1136 unsigned long align, unsigned long vstart)
1137{
1138 unsigned long nva_start_addr;
1139
1140 if (va->va_start > vstart)
1141 nva_start_addr = ALIGN(va->va_start, align);
1142 else
1143 nva_start_addr = ALIGN(vstart, align);
1144
1145 /* Can be overflowed due to big size or alignment. */
1146 if (nva_start_addr + size < nva_start_addr ||
1147 nva_start_addr < vstart)
1148 return false;
1149
1150 return (nva_start_addr + size <= va->va_end);
1151}
1152
1153/*
1154 * Find the first free block(lowest start address) in the tree,
1155 * that will accomplish the request corresponding to passing
1156 * parameters.
1157 */
1158static __always_inline struct vmap_area *
1159find_vmap_lowest_match(unsigned long size,
1160 unsigned long align, unsigned long vstart)
1161{
1162 struct vmap_area *va;
1163 struct rb_node *node;
1164 unsigned long length;
1165
1166 /* Start from the root. */
1167 node = free_vmap_area_root.rb_node;
1168
1169 /* Adjust the search size for alignment overhead. */
1170 length = size + align - 1;
1171
1172 while (node) {
1173 va = rb_entry(node, struct vmap_area, rb_node);
1174
1175 if (get_subtree_max_size(node->rb_left) >= length &&
1176 vstart < va->va_start) {
1177 node = node->rb_left;
1178 } else {
1179 if (is_within_this_va(va, size, align, vstart))
1180 return va;
1181
1182 /*
1183 * Does not make sense to go deeper towards the right
1184 * sub-tree if it does not have a free block that is
1185 * equal or bigger to the requested search length.
1186 */
1187 if (get_subtree_max_size(node->rb_right) >= length) {
1188 node = node->rb_right;
1189 continue;
1190 }
1191
1192 /*
1193 * OK. We roll back and find the first right sub-tree,
1194 * that will satisfy the search criteria. It can happen
1195 * only once due to "vstart" restriction.
1196 */
1197 while ((node = rb_parent(node))) {
1198 va = rb_entry(node, struct vmap_area, rb_node);
1199 if (is_within_this_va(va, size, align, vstart))
1200 return va;
1201
1202 if (get_subtree_max_size(node->rb_right) >= length &&
1203 vstart <= va->va_start) {
1204 node = node->rb_right;
1205 break;
1206 }
1207 }
1208 }
1209 }
1210
1211 return NULL;
1212}
1213
1214#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1215#include <linux/random.h>
1216
1217static struct vmap_area *
1218find_vmap_lowest_linear_match(unsigned long size,
1219 unsigned long align, unsigned long vstart)
1220{
1221 struct vmap_area *va;
1222
1223 list_for_each_entry(va, &free_vmap_area_list, list) {
1224 if (!is_within_this_va(va, size, align, vstart))
1225 continue;
1226
1227 return va;
1228 }
1229
1230 return NULL;
1231}
1232
1233static void
1234find_vmap_lowest_match_check(unsigned long size)
1235{
1236 struct vmap_area *va_1, *va_2;
1237 unsigned long vstart;
1238 unsigned int rnd;
1239
1240 get_random_bytes(&rnd, sizeof(rnd));
1241 vstart = VMALLOC_START + rnd;
1242
1243 va_1 = find_vmap_lowest_match(size, 1, vstart);
1244 va_2 = find_vmap_lowest_linear_match(size, 1, vstart);
1245
1246 if (va_1 != va_2)
1247 pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
1248 va_1, va_2, vstart);
1249}
1250#endif
1251
1252enum fit_type {
1253 NOTHING_FIT = 0,
1254 FL_FIT_TYPE = 1, /* full fit */
1255 LE_FIT_TYPE = 2, /* left edge fit */
1256 RE_FIT_TYPE = 3, /* right edge fit */
1257 NE_FIT_TYPE = 4 /* no edge fit */
1258};
1259
1260static __always_inline enum fit_type
1261classify_va_fit_type(struct vmap_area *va,
1262 unsigned long nva_start_addr, unsigned long size)
1263{
1264 enum fit_type type;
1265
1266 /* Check if it is within VA. */
1267 if (nva_start_addr < va->va_start ||
1268 nva_start_addr + size > va->va_end)
1269 return NOTHING_FIT;
1270
1271 /* Now classify. */
1272 if (va->va_start == nva_start_addr) {
1273 if (va->va_end == nva_start_addr + size)
1274 type = FL_FIT_TYPE;
1275 else
1276 type = LE_FIT_TYPE;
1277 } else if (va->va_end == nva_start_addr + size) {
1278 type = RE_FIT_TYPE;
1279 } else {
1280 type = NE_FIT_TYPE;
1281 }
1282
1283 return type;
1284}
1285
1286static __always_inline int
1287adjust_va_to_fit_type(struct vmap_area *va,
1288 unsigned long nva_start_addr, unsigned long size,
1289 enum fit_type type)
1290{
1291 struct vmap_area *lva = NULL;
1292
1293 if (type == FL_FIT_TYPE) {
1294 /*
1295 * No need to split VA, it fully fits.
1296 *
1297 * | |
1298 * V NVA V
1299 * |---------------|
1300 */
1301 unlink_va(va, &free_vmap_area_root);
1302 kmem_cache_free(vmap_area_cachep, va);
1303 } else if (type == LE_FIT_TYPE) {
1304 /*
1305 * Split left edge of fit VA.
1306 *
1307 * | |
1308 * V NVA V R
1309 * |-------|-------|
1310 */
1311 va->va_start += size;
1312 } else if (type == RE_FIT_TYPE) {
1313 /*
1314 * Split right edge of fit VA.
1315 *
1316 * | |
1317 * L V NVA V
1318 * |-------|-------|
1319 */
1320 va->va_end = nva_start_addr;
1321 } else if (type == NE_FIT_TYPE) {
1322 /*
1323 * Split no edge of fit VA.
1324 *
1325 * | |
1326 * L V NVA V R
1327 * |---|-------|---|
1328 */
1329 lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
1330 if (unlikely(!lva)) {
1331 /*
1332 * For percpu allocator we do not do any pre-allocation
1333 * and leave it as it is. The reason is it most likely
1334 * never ends up with NE_FIT_TYPE splitting. In case of
1335 * percpu allocations offsets and sizes are aligned to
1336 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
1337 * are its main fitting cases.
1338 *
1339 * There are a few exceptions though, as an example it is
1340 * a first allocation (early boot up) when we have "one"
1341 * big free space that has to be split.
1342 *
1343 * Also we can hit this path in case of regular "vmap"
1344 * allocations, if "this" current CPU was not preloaded.
1345 * See the comment in alloc_vmap_area() why. If so, then
1346 * GFP_NOWAIT is used instead to get an extra object for
1347 * split purpose. That is rare and most time does not
1348 * occur.
1349 *
1350 * What happens if an allocation gets failed. Basically,
1351 * an "overflow" path is triggered to purge lazily freed
1352 * areas to free some memory, then, the "retry" path is
1353 * triggered to repeat one more time. See more details
1354 * in alloc_vmap_area() function.
1355 */
1356 lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
1357 if (!lva)
1358 return -1;
1359 }
1360
1361 /*
1362 * Build the remainder.
1363 */
1364 lva->va_start = va->va_start;
1365 lva->va_end = nva_start_addr;
1366
1367 /*
1368 * Shrink this VA to remaining size.
1369 */
1370 va->va_start = nva_start_addr + size;
1371 } else {
1372 return -1;
1373 }
1374
1375 if (type != FL_FIT_TYPE) {
1376 augment_tree_propagate_from(va);
1377
1378 if (lva) /* type == NE_FIT_TYPE */
1379 insert_vmap_area_augment(lva, &va->rb_node,
1380 &free_vmap_area_root, &free_vmap_area_list);
1381 }
1382
1383 return 0;
1384}
1385
1386/*
1387 * Returns a start address of the newly allocated area, if success.
1388 * Otherwise a vend is returned that indicates failure.
1389 */
1390static __always_inline unsigned long
1391__alloc_vmap_area(unsigned long size, unsigned long align,
1392 unsigned long vstart, unsigned long vend)
1393{
1394 unsigned long nva_start_addr;
1395 struct vmap_area *va;
1396 enum fit_type type;
1397 int ret;
1398
1399 va = find_vmap_lowest_match(size, align, vstart);
1400 if (unlikely(!va))
1401 return vend;
1402
1403 if (va->va_start > vstart)
1404 nva_start_addr = ALIGN(va->va_start, align);
1405 else
1406 nva_start_addr = ALIGN(vstart, align);
1407
1408 /* Check the "vend" restriction. */
1409 if (nva_start_addr + size > vend)
1410 return vend;
1411
1412 /* Classify what we have found. */
1413 type = classify_va_fit_type(va, nva_start_addr, size);
1414 if (WARN_ON_ONCE(type == NOTHING_FIT))
1415 return vend;
1416
1417 /* Update the free vmap_area. */
1418 ret = adjust_va_to_fit_type(va, nva_start_addr, size, type);
1419 if (ret)
1420 return vend;
1421
1422#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
1423 find_vmap_lowest_match_check(size);
1424#endif
1425
1426 return nva_start_addr;
1427}
1428
1429/*
1430 * Free a region of KVA allocated by alloc_vmap_area
1431 */
1432static void free_vmap_area(struct vmap_area *va)
1433{
1434 /*
1435 * Remove from the busy tree/list.
1436 */
1437 spin_lock(&vmap_area_lock);
1438 unlink_va(va, &vmap_area_root);
1439 spin_unlock(&vmap_area_lock);
1440
1441 /*
1442 * Insert/Merge it back to the free tree/list.
1443 */
1444 spin_lock(&free_vmap_area_lock);
1445 merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list);
1446 spin_unlock(&free_vmap_area_lock);
1447}
1448
1449static inline void
1450preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
1451{
1452 struct vmap_area *va = NULL;
1453
1454 /*
1455 * Preload this CPU with one extra vmap_area object. It is used
1456 * when fit type of free area is NE_FIT_TYPE. It guarantees that
1457 * a CPU that does an allocation is preloaded.
1458 *
1459 * We do it in non-atomic context, thus it allows us to use more
1460 * permissive allocation masks to be more stable under low memory
1461 * condition and high memory pressure.
1462 */
1463 if (!this_cpu_read(ne_fit_preload_node))
1464 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1465
1466 spin_lock(lock);
1467
1468 if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va))
1469 kmem_cache_free(vmap_area_cachep, va);
1470}
1471
1472/*
1473 * Allocate a region of KVA of the specified size and alignment, within the
1474 * vstart and vend.
1475 */
1476static struct vmap_area *alloc_vmap_area(unsigned long size,
1477 unsigned long align,
1478 unsigned long vstart, unsigned long vend,
1479 int node, gfp_t gfp_mask)
1480{
1481 struct vmap_area *va;
1482 unsigned long addr;
1483 int purged = 0;
1484 int ret;
1485
1486 BUG_ON(!size);
1487 BUG_ON(offset_in_page(size));
1488 BUG_ON(!is_power_of_2(align));
1489
1490 if (unlikely(!vmap_initialized))
1491 return ERR_PTR(-EBUSY);
1492
1493 might_sleep();
1494 gfp_mask = gfp_mask & GFP_RECLAIM_MASK;
1495
1496 va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
1497 if (unlikely(!va))
1498 return ERR_PTR(-ENOMEM);
1499
1500 /*
1501 * Only scan the relevant parts containing pointers to other objects
1502 * to avoid false negatives.
1503 */
1504 kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask);
1505
1506retry:
1507 preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node);
1508 addr = __alloc_vmap_area(size, align, vstart, vend);
1509 spin_unlock(&free_vmap_area_lock);
1510
1511 /*
1512 * If an allocation fails, the "vend" address is
1513 * returned. Therefore trigger the overflow path.
1514 */
1515 if (unlikely(addr == vend))
1516 goto overflow;
1517
1518 va->va_start = addr;
1519 va->va_end = addr + size;
1520 va->vm = NULL;
1521
1522 spin_lock(&vmap_area_lock);
1523 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
1524 spin_unlock(&vmap_area_lock);
1525
1526 BUG_ON(!IS_ALIGNED(va->va_start, align));
1527 BUG_ON(va->va_start < vstart);
1528 BUG_ON(va->va_end > vend);
1529
1530 ret = kasan_populate_vmalloc(addr, size);
1531 if (ret) {
1532 free_vmap_area(va);
1533 return ERR_PTR(ret);
1534 }
1535
1536 return va;
1537
1538overflow:
1539 if (!purged) {
1540 purge_vmap_area_lazy();
1541 purged = 1;
1542 goto retry;
1543 }
1544
1545 if (gfpflags_allow_blocking(gfp_mask)) {
1546 unsigned long freed = 0;
1547 blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
1548 if (freed > 0) {
1549 purged = 0;
1550 goto retry;
1551 }
1552 }
1553
1554 if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
1555 pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
1556 size);
1557
1558 kmem_cache_free(vmap_area_cachep, va);
1559 return ERR_PTR(-EBUSY);
1560}
1561
1562int register_vmap_purge_notifier(struct notifier_block *nb)
1563{
1564 return blocking_notifier_chain_register(&vmap_notify_list, nb);
1565}
1566EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
1567
1568int unregister_vmap_purge_notifier(struct notifier_block *nb)
1569{
1570 return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
1571}
1572EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
1573
1574/*
1575 * lazy_max_pages is the maximum amount of virtual address space we gather up
1576 * before attempting to purge with a TLB flush.
1577 *
1578 * There is a tradeoff here: a larger number will cover more kernel page tables
1579 * and take slightly longer to purge, but it will linearly reduce the number of
1580 * global TLB flushes that must be performed. It would seem natural to scale
1581 * this number up linearly with the number of CPUs (because vmapping activity
1582 * could also scale linearly with the number of CPUs), however it is likely
1583 * that in practice, workloads might be constrained in other ways that mean
1584 * vmap activity will not scale linearly with CPUs. Also, I want to be
1585 * conservative and not introduce a big latency on huge systems, so go with
1586 * a less aggressive log scale. It will still be an improvement over the old
1587 * code, and it will be simple to change the scale factor if we find that it
1588 * becomes a problem on bigger systems.
1589 */
1590static unsigned long lazy_max_pages(void)
1591{
1592 unsigned int log;
1593
1594 log = fls(num_online_cpus());
1595
1596 return log * (32UL * 1024 * 1024 / PAGE_SIZE);
1597}
1598
1599static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
1600
1601/*
1602 * Serialize vmap purging. There is no actual critical section protected
1603 * by this look, but we want to avoid concurrent calls for performance
1604 * reasons and to make the pcpu_get_vm_areas more deterministic.
1605 */
1606static DEFINE_MUTEX(vmap_purge_lock);
1607
1608/* for per-CPU blocks */
1609static void purge_fragmented_blocks_allcpus(void);
1610
1611#ifdef CONFIG_X86_64
1612/*
1613 * called before a call to iounmap() if the caller wants vm_area_struct's
1614 * immediately freed.
1615 */
1616void set_iounmap_nonlazy(void)
1617{
1618 atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1);
1619}
1620#endif /* CONFIG_X86_64 */
1621
1622/*
1623 * Purges all lazily-freed vmap areas.
1624 */
1625static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
1626{
1627 unsigned long resched_threshold;
1628 struct list_head local_pure_list;
1629 struct vmap_area *va, *n_va;
1630
1631 lockdep_assert_held(&vmap_purge_lock);
1632
1633 spin_lock(&purge_vmap_area_lock);
1634 purge_vmap_area_root = RB_ROOT;
1635 list_replace_init(&purge_vmap_area_list, &local_pure_list);
1636 spin_unlock(&purge_vmap_area_lock);
1637
1638 if (unlikely(list_empty(&local_pure_list)))
1639 return false;
1640
1641 start = min(start,
1642 list_first_entry(&local_pure_list,
1643 struct vmap_area, list)->va_start);
1644
1645 end = max(end,
1646 list_last_entry(&local_pure_list,
1647 struct vmap_area, list)->va_end);
1648
1649 flush_tlb_kernel_range(start, end);
1650 resched_threshold = lazy_max_pages() << 1;
1651
1652 spin_lock(&free_vmap_area_lock);
1653 list_for_each_entry_safe(va, n_va, &local_pure_list, list) {
1654 unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
1655 unsigned long orig_start = va->va_start;
1656 unsigned long orig_end = va->va_end;
1657
1658 /*
1659 * Finally insert or merge lazily-freed area. It is
1660 * detached and there is no need to "unlink" it from
1661 * anything.
1662 */
1663 va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root,
1664 &free_vmap_area_list);
1665
1666 if (!va)
1667 continue;
1668
1669 if (is_vmalloc_or_module_addr((void *)orig_start))
1670 kasan_release_vmalloc(orig_start, orig_end,
1671 va->va_start, va->va_end);
1672
1673 atomic_long_sub(nr, &vmap_lazy_nr);
1674
1675 if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
1676 cond_resched_lock(&free_vmap_area_lock);
1677 }
1678 spin_unlock(&free_vmap_area_lock);
1679 return true;
1680}
1681
1682/*
1683 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
1684 * is already purging.
1685 */
1686static void try_purge_vmap_area_lazy(void)
1687{
1688 if (mutex_trylock(&vmap_purge_lock)) {
1689 __purge_vmap_area_lazy(ULONG_MAX, 0);
1690 mutex_unlock(&vmap_purge_lock);
1691 }
1692}
1693
1694/*
1695 * Kick off a purge of the outstanding lazy areas.
1696 */
1697static void purge_vmap_area_lazy(void)
1698{
1699 mutex_lock(&vmap_purge_lock);
1700 purge_fragmented_blocks_allcpus();
1701 __purge_vmap_area_lazy(ULONG_MAX, 0);
1702 mutex_unlock(&vmap_purge_lock);
1703}
1704
1705/*
1706 * Free a vmap area, caller ensuring that the area has been unmapped
1707 * and flush_cache_vunmap had been called for the correct range
1708 * previously.
1709 */
1710static void free_vmap_area_noflush(struct vmap_area *va)
1711{
1712 unsigned long nr_lazy;
1713
1714 spin_lock(&vmap_area_lock);
1715 unlink_va(va, &vmap_area_root);
1716 spin_unlock(&vmap_area_lock);
1717
1718 nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
1719 PAGE_SHIFT, &vmap_lazy_nr);
1720
1721 /*
1722 * Merge or place it to the purge tree/list.
1723 */
1724 spin_lock(&purge_vmap_area_lock);
1725 merge_or_add_vmap_area(va,
1726 &purge_vmap_area_root, &purge_vmap_area_list);
1727 spin_unlock(&purge_vmap_area_lock);
1728
1729 /* After this point, we may free va at any time */
1730 if (unlikely(nr_lazy > lazy_max_pages()))
1731 try_purge_vmap_area_lazy();
1732}
1733
1734/*
1735 * Free and unmap a vmap area
1736 */
1737static void free_unmap_vmap_area(struct vmap_area *va)
1738{
1739 flush_cache_vunmap(va->va_start, va->va_end);
1740 vunmap_range_noflush(va->va_start, va->va_end);
1741 if (debug_pagealloc_enabled_static())
1742 flush_tlb_kernel_range(va->va_start, va->va_end);
1743
1744 free_vmap_area_noflush(va);
1745}
1746
1747static struct vmap_area *find_vmap_area(unsigned long addr)
1748{
1749 struct vmap_area *va;
1750
1751 spin_lock(&vmap_area_lock);
1752 va = __find_vmap_area(addr);
1753 spin_unlock(&vmap_area_lock);
1754
1755 return va;
1756}
1757
1758/*** Per cpu kva allocator ***/
1759
1760/*
1761 * vmap space is limited especially on 32 bit architectures. Ensure there is
1762 * room for at least 16 percpu vmap blocks per CPU.
1763 */
1764/*
1765 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
1766 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess
1767 * instead (we just need a rough idea)
1768 */
1769#if BITS_PER_LONG == 32
1770#define VMALLOC_SPACE (128UL*1024*1024)
1771#else
1772#define VMALLOC_SPACE (128UL*1024*1024*1024)
1773#endif
1774
1775#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE)
1776#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */
1777#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */
1778#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2)
1779#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */
1780#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */
1781#define VMAP_BBMAP_BITS \
1782 VMAP_MIN(VMAP_BBMAP_BITS_MAX, \
1783 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \
1784 VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
1785
1786#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE)
1787
1788struct vmap_block_queue {
1789 spinlock_t lock;
1790 struct list_head free;
1791};
1792
1793struct vmap_block {
1794 spinlock_t lock;
1795 struct vmap_area *va;
1796 unsigned long free, dirty;
1797 unsigned long dirty_min, dirty_max; /*< dirty range */
1798 struct list_head free_list;
1799 struct rcu_head rcu_head;
1800 struct list_head purge;
1801};
1802
1803/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
1804static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
1805
1806/*
1807 * XArray of vmap blocks, indexed by address, to quickly find a vmap block
1808 * in the free path. Could get rid of this if we change the API to return a
1809 * "cookie" from alloc, to be passed to free. But no big deal yet.
1810 */
1811static DEFINE_XARRAY(vmap_blocks);
1812
1813/*
1814 * We should probably have a fallback mechanism to allocate virtual memory
1815 * out of partially filled vmap blocks. However vmap block sizing should be
1816 * fairly reasonable according to the vmalloc size, so it shouldn't be a
1817 * big problem.
1818 */
1819
1820static unsigned long addr_to_vb_idx(unsigned long addr)
1821{
1822 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
1823 addr /= VMAP_BLOCK_SIZE;
1824 return addr;
1825}
1826
1827static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
1828{
1829 unsigned long addr;
1830
1831 addr = va_start + (pages_off << PAGE_SHIFT);
1832 BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
1833 return (void *)addr;
1834}
1835
1836/**
1837 * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
1838 * block. Of course pages number can't exceed VMAP_BBMAP_BITS
1839 * @order: how many 2^order pages should be occupied in newly allocated block
1840 * @gfp_mask: flags for the page level allocator
1841 *
1842 * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
1843 */
1844static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
1845{
1846 struct vmap_block_queue *vbq;
1847 struct vmap_block *vb;
1848 struct vmap_area *va;
1849 unsigned long vb_idx;
1850 int node, err;
1851 void *vaddr;
1852
1853 node = numa_node_id();
1854
1855 vb = kmalloc_node(sizeof(struct vmap_block),
1856 gfp_mask & GFP_RECLAIM_MASK, node);
1857 if (unlikely(!vb))
1858 return ERR_PTR(-ENOMEM);
1859
1860 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
1861 VMALLOC_START, VMALLOC_END,
1862 node, gfp_mask);
1863 if (IS_ERR(va)) {
1864 kfree(vb);
1865 return ERR_CAST(va);
1866 }
1867
1868 vaddr = vmap_block_vaddr(va->va_start, 0);
1869 spin_lock_init(&vb->lock);
1870 vb->va = va;
1871 /* At least something should be left free */
1872 BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
1873 vb->free = VMAP_BBMAP_BITS - (1UL << order);
1874 vb->dirty = 0;
1875 vb->dirty_min = VMAP_BBMAP_BITS;
1876 vb->dirty_max = 0;
1877 INIT_LIST_HEAD(&vb->free_list);
1878
1879 vb_idx = addr_to_vb_idx(va->va_start);
1880 err = xa_insert(&vmap_blocks, vb_idx, vb, gfp_mask);
1881 if (err) {
1882 kfree(vb);
1883 free_vmap_area(va);
1884 return ERR_PTR(err);
1885 }
1886
1887 vbq = &get_cpu_var(vmap_block_queue);
1888 spin_lock(&vbq->lock);
1889 list_add_tail_rcu(&vb->free_list, &vbq->free);
1890 spin_unlock(&vbq->lock);
1891 put_cpu_var(vmap_block_queue);
1892
1893 return vaddr;
1894}
1895
1896static void free_vmap_block(struct vmap_block *vb)
1897{
1898 struct vmap_block *tmp;
1899
1900 tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start));
1901 BUG_ON(tmp != vb);
1902
1903 free_vmap_area_noflush(vb->va);
1904 kfree_rcu(vb, rcu_head);
1905}
1906
1907static void purge_fragmented_blocks(int cpu)
1908{
1909 LIST_HEAD(purge);
1910 struct vmap_block *vb;
1911 struct vmap_block *n_vb;
1912 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
1913
1914 rcu_read_lock();
1915 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1916
1917 if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
1918 continue;
1919
1920 spin_lock(&vb->lock);
1921 if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
1922 vb->free = 0; /* prevent further allocs after releasing lock */
1923 vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
1924 vb->dirty_min = 0;
1925 vb->dirty_max = VMAP_BBMAP_BITS;
1926 spin_lock(&vbq->lock);
1927 list_del_rcu(&vb->free_list);
1928 spin_unlock(&vbq->lock);
1929 spin_unlock(&vb->lock);
1930 list_add_tail(&vb->purge, &purge);
1931 } else
1932 spin_unlock(&vb->lock);
1933 }
1934 rcu_read_unlock();
1935
1936 list_for_each_entry_safe(vb, n_vb, &purge, purge) {
1937 list_del(&vb->purge);
1938 free_vmap_block(vb);
1939 }
1940}
1941
1942static void purge_fragmented_blocks_allcpus(void)
1943{
1944 int cpu;
1945
1946 for_each_possible_cpu(cpu)
1947 purge_fragmented_blocks(cpu);
1948}
1949
1950static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
1951{
1952 struct vmap_block_queue *vbq;
1953 struct vmap_block *vb;
1954 void *vaddr = NULL;
1955 unsigned int order;
1956
1957 BUG_ON(offset_in_page(size));
1958 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
1959 if (WARN_ON(size == 0)) {
1960 /*
1961 * Allocating 0 bytes isn't what caller wants since
1962 * get_order(0) returns funny result. Just warn and terminate
1963 * early.
1964 */
1965 return NULL;
1966 }
1967 order = get_order(size);
1968
1969 rcu_read_lock();
1970 vbq = &get_cpu_var(vmap_block_queue);
1971 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1972 unsigned long pages_off;
1973
1974 spin_lock(&vb->lock);
1975 if (vb->free < (1UL << order)) {
1976 spin_unlock(&vb->lock);
1977 continue;
1978 }
1979
1980 pages_off = VMAP_BBMAP_BITS - vb->free;
1981 vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
1982 vb->free -= 1UL << order;
1983 if (vb->free == 0) {
1984 spin_lock(&vbq->lock);
1985 list_del_rcu(&vb->free_list);
1986 spin_unlock(&vbq->lock);
1987 }
1988
1989 spin_unlock(&vb->lock);
1990 break;
1991 }
1992
1993 put_cpu_var(vmap_block_queue);
1994 rcu_read_unlock();
1995
1996 /* Allocate new block if nothing was found */
1997 if (!vaddr)
1998 vaddr = new_vmap_block(order, gfp_mask);
1999
2000 return vaddr;
2001}
2002
2003static void vb_free(unsigned long addr, unsigned long size)
2004{
2005 unsigned long offset;
2006 unsigned int order;
2007 struct vmap_block *vb;
2008
2009 BUG_ON(offset_in_page(size));
2010 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
2011
2012 flush_cache_vunmap(addr, addr + size);
2013
2014 order = get_order(size);
2015 offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
2016 vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr));
2017
2018 vunmap_range_noflush(addr, addr + size);
2019
2020 if (debug_pagealloc_enabled_static())
2021 flush_tlb_kernel_range(addr, addr + size);
2022
2023 spin_lock(&vb->lock);
2024
2025 /* Expand dirty range */
2026 vb->dirty_min = min(vb->dirty_min, offset);
2027 vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
2028
2029 vb->dirty += 1UL << order;
2030 if (vb->dirty == VMAP_BBMAP_BITS) {
2031 BUG_ON(vb->free);
2032 spin_unlock(&vb->lock);
2033 free_vmap_block(vb);
2034 } else
2035 spin_unlock(&vb->lock);
2036}
2037
2038static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
2039{
2040 int cpu;
2041
2042 if (unlikely(!vmap_initialized))
2043 return;
2044
2045 might_sleep();
2046
2047 for_each_possible_cpu(cpu) {
2048 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
2049 struct vmap_block *vb;
2050
2051 rcu_read_lock();
2052 list_for_each_entry_rcu(vb, &vbq->free, free_list) {
2053 spin_lock(&vb->lock);
2054 if (vb->dirty && vb->dirty != VMAP_BBMAP_BITS) {
2055 unsigned long va_start = vb->va->va_start;
2056 unsigned long s, e;
2057
2058 s = va_start + (vb->dirty_min << PAGE_SHIFT);
2059 e = va_start + (vb->dirty_max << PAGE_SHIFT);
2060
2061 start = min(s, start);
2062 end = max(e, end);
2063
2064 flush = 1;
2065 }
2066 spin_unlock(&vb->lock);
2067 }
2068 rcu_read_unlock();
2069 }
2070
2071 mutex_lock(&vmap_purge_lock);
2072 purge_fragmented_blocks_allcpus();
2073 if (!__purge_vmap_area_lazy(start, end) && flush)
2074 flush_tlb_kernel_range(start, end);
2075 mutex_unlock(&vmap_purge_lock);
2076}
2077
2078/**
2079 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
2080 *
2081 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
2082 * to amortize TLB flushing overheads. What this means is that any page you
2083 * have now, may, in a former life, have been mapped into kernel virtual
2084 * address by the vmap layer and so there might be some CPUs with TLB entries
2085 * still referencing that page (additional to the regular 1:1 kernel mapping).
2086 *
2087 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
2088 * be sure that none of the pages we have control over will have any aliases
2089 * from the vmap layer.
2090 */
2091void vm_unmap_aliases(void)
2092{
2093 unsigned long start = ULONG_MAX, end = 0;
2094 int flush = 0;
2095
2096 _vm_unmap_aliases(start, end, flush);
2097}
2098EXPORT_SYMBOL_GPL(vm_unmap_aliases);
2099
2100/**
2101 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
2102 * @mem: the pointer returned by vm_map_ram
2103 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
2104 */
2105void vm_unmap_ram(const void *mem, unsigned int count)
2106{
2107 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2108 unsigned long addr = (unsigned long)mem;
2109 struct vmap_area *va;
2110
2111 might_sleep();
2112 BUG_ON(!addr);
2113 BUG_ON(addr < VMALLOC_START);
2114 BUG_ON(addr > VMALLOC_END);
2115 BUG_ON(!PAGE_ALIGNED(addr));
2116
2117 kasan_poison_vmalloc(mem, size);
2118
2119 if (likely(count <= VMAP_MAX_ALLOC)) {
2120 debug_check_no_locks_freed(mem, size);
2121 vb_free(addr, size);
2122 return;
2123 }
2124
2125 va = find_vmap_area(addr);
2126 BUG_ON(!va);
2127 debug_check_no_locks_freed((void *)va->va_start,
2128 (va->va_end - va->va_start));
2129 free_unmap_vmap_area(va);
2130}
2131EXPORT_SYMBOL(vm_unmap_ram);
2132
2133/**
2134 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
2135 * @pages: an array of pointers to the pages to be mapped
2136 * @count: number of pages
2137 * @node: prefer to allocate data structures on this node
2138 *
2139 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
2140 * faster than vmap so it's good. But if you mix long-life and short-life
2141 * objects with vm_map_ram(), it could consume lots of address space through
2142 * fragmentation (especially on a 32bit machine). You could see failures in
2143 * the end. Please use this function for short-lived objects.
2144 *
2145 * Returns: a pointer to the address that has been mapped, or %NULL on failure
2146 */
2147void *vm_map_ram(struct page **pages, unsigned int count, int node)
2148{
2149 unsigned long size = (unsigned long)count << PAGE_SHIFT;
2150 unsigned long addr;
2151 void *mem;
2152
2153 if (likely(count <= VMAP_MAX_ALLOC)) {
2154 mem = vb_alloc(size, GFP_KERNEL);
2155 if (IS_ERR(mem))
2156 return NULL;
2157 addr = (unsigned long)mem;
2158 } else {
2159 struct vmap_area *va;
2160 va = alloc_vmap_area(size, PAGE_SIZE,
2161 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
2162 if (IS_ERR(va))
2163 return NULL;
2164
2165 addr = va->va_start;
2166 mem = (void *)addr;
2167 }
2168
2169 kasan_unpoison_vmalloc(mem, size);
2170
2171 if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
2172 pages, PAGE_SHIFT) < 0) {
2173 vm_unmap_ram(mem, count);
2174 return NULL;
2175 }
2176
2177 return mem;
2178}
2179EXPORT_SYMBOL(vm_map_ram);
2180
2181static struct vm_struct *vmlist __initdata;
2182
2183static inline unsigned int vm_area_page_order(struct vm_struct *vm)
2184{
2185#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2186 return vm->page_order;
2187#else
2188 return 0;
2189#endif
2190}
2191
2192static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
2193{
2194#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
2195 vm->page_order = order;
2196#else
2197 BUG_ON(order != 0);
2198#endif
2199}
2200
2201/**
2202 * vm_area_add_early - add vmap area early during boot
2203 * @vm: vm_struct to add
2204 *
2205 * This function is used to add fixed kernel vm area to vmlist before
2206 * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags
2207 * should contain proper values and the other fields should be zero.
2208 *
2209 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2210 */
2211void __init vm_area_add_early(struct vm_struct *vm)
2212{
2213 struct vm_struct *tmp, **p;
2214
2215 BUG_ON(vmap_initialized);
2216 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
2217 if (tmp->addr >= vm->addr) {
2218 BUG_ON(tmp->addr < vm->addr + vm->size);
2219 break;
2220 } else
2221 BUG_ON(tmp->addr + tmp->size > vm->addr);
2222 }
2223 vm->next = *p;
2224 *p = vm;
2225}
2226
2227/**
2228 * vm_area_register_early - register vmap area early during boot
2229 * @vm: vm_struct to register
2230 * @align: requested alignment
2231 *
2232 * This function is used to register kernel vm area before
2233 * vmalloc_init() is called. @vm->size and @vm->flags should contain
2234 * proper values on entry and other fields should be zero. On return,
2235 * vm->addr contains the allocated address.
2236 *
2237 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
2238 */
2239void __init vm_area_register_early(struct vm_struct *vm, size_t align)
2240{
2241 static size_t vm_init_off __initdata;
2242 unsigned long addr;
2243
2244 addr = ALIGN(VMALLOC_START + vm_init_off, align);
2245 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
2246
2247 vm->addr = (void *)addr;
2248
2249 vm_area_add_early(vm);
2250}
2251
2252static void vmap_init_free_space(void)
2253{
2254 unsigned long vmap_start = 1;
2255 const unsigned long vmap_end = ULONG_MAX;
2256 struct vmap_area *busy, *free;
2257
2258 /*
2259 * B F B B B F
2260 * -|-----|.....|-----|-----|-----|.....|-
2261 * | The KVA space |
2262 * |<--------------------------------->|
2263 */
2264 list_for_each_entry(busy, &vmap_area_list, list) {
2265 if (busy->va_start - vmap_start > 0) {
2266 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2267 if (!WARN_ON_ONCE(!free)) {
2268 free->va_start = vmap_start;
2269 free->va_end = busy->va_start;
2270
2271 insert_vmap_area_augment(free, NULL,
2272 &free_vmap_area_root,
2273 &free_vmap_area_list);
2274 }
2275 }
2276
2277 vmap_start = busy->va_end;
2278 }
2279
2280 if (vmap_end - vmap_start > 0) {
2281 free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2282 if (!WARN_ON_ONCE(!free)) {
2283 free->va_start = vmap_start;
2284 free->va_end = vmap_end;
2285
2286 insert_vmap_area_augment(free, NULL,
2287 &free_vmap_area_root,
2288 &free_vmap_area_list);
2289 }
2290 }
2291}
2292
2293void __init vmalloc_init(void)
2294{
2295 struct vmap_area *va;
2296 struct vm_struct *tmp;
2297 int i;
2298
2299 /*
2300 * Create the cache for vmap_area objects.
2301 */
2302 vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
2303
2304 for_each_possible_cpu(i) {
2305 struct vmap_block_queue *vbq;
2306 struct vfree_deferred *p;
2307
2308 vbq = &per_cpu(vmap_block_queue, i);
2309 spin_lock_init(&vbq->lock);
2310 INIT_LIST_HEAD(&vbq->free);
2311 p = &per_cpu(vfree_deferred, i);
2312 init_llist_head(&p->list);
2313 INIT_WORK(&p->wq, free_work);
2314 }
2315
2316 /* Import existing vmlist entries. */
2317 for (tmp = vmlist; tmp; tmp = tmp->next) {
2318 va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
2319 if (WARN_ON_ONCE(!va))
2320 continue;
2321
2322 va->va_start = (unsigned long)tmp->addr;
2323 va->va_end = va->va_start + tmp->size;
2324 va->vm = tmp;
2325 insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
2326 }
2327
2328 /*
2329 * Now we can initialize a free vmap space.
2330 */
2331 vmap_init_free_space();
2332 vmap_initialized = true;
2333}
2334
2335static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
2336 struct vmap_area *va, unsigned long flags, const void *caller)
2337{
2338 vm->flags = flags;
2339 vm->addr = (void *)va->va_start;
2340 vm->size = va->va_end - va->va_start;
2341 vm->caller = caller;
2342 va->vm = vm;
2343}
2344
2345static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
2346 unsigned long flags, const void *caller)
2347{
2348 spin_lock(&vmap_area_lock);
2349 setup_vmalloc_vm_locked(vm, va, flags, caller);
2350 spin_unlock(&vmap_area_lock);
2351}
2352
2353static void clear_vm_uninitialized_flag(struct vm_struct *vm)
2354{
2355 /*
2356 * Before removing VM_UNINITIALIZED,
2357 * we should make sure that vm has proper values.
2358 * Pair with smp_rmb() in show_numa_info().
2359 */
2360 smp_wmb();
2361 vm->flags &= ~VM_UNINITIALIZED;
2362}
2363
2364static struct vm_struct *__get_vm_area_node(unsigned long size,
2365 unsigned long align, unsigned long shift, unsigned long flags,
2366 unsigned long start, unsigned long end, int node,
2367 gfp_t gfp_mask, const void *caller)
2368{
2369 struct vmap_area *va;
2370 struct vm_struct *area;
2371 unsigned long requested_size = size;
2372
2373 BUG_ON(in_interrupt());
2374 size = ALIGN(size, 1ul << shift);
2375 if (unlikely(!size))
2376 return NULL;
2377
2378 if (flags & VM_IOREMAP)
2379 align = 1ul << clamp_t(int, get_count_order_long(size),
2380 PAGE_SHIFT, IOREMAP_MAX_ORDER);
2381
2382 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
2383 if (unlikely(!area))
2384 return NULL;
2385
2386 if (!(flags & VM_NO_GUARD))
2387 size += PAGE_SIZE;
2388
2389 va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
2390 if (IS_ERR(va)) {
2391 kfree(area);
2392 return NULL;
2393 }
2394
2395 kasan_unpoison_vmalloc((void *)va->va_start, requested_size);
2396
2397 setup_vmalloc_vm(area, va, flags, caller);
2398
2399 return area;
2400}
2401
2402struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
2403 unsigned long start, unsigned long end,
2404 const void *caller)
2405{
2406 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end,
2407 NUMA_NO_NODE, GFP_KERNEL, caller);
2408}
2409
2410/**
2411 * get_vm_area - reserve a contiguous kernel virtual area
2412 * @size: size of the area
2413 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC
2414 *
2415 * Search an area of @size in the kernel virtual mapping area,
2416 * and reserved it for out purposes. Returns the area descriptor
2417 * on success or %NULL on failure.
2418 *
2419 * Return: the area descriptor on success or %NULL on failure.
2420 */
2421struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
2422{
2423 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2424 VMALLOC_START, VMALLOC_END,
2425 NUMA_NO_NODE, GFP_KERNEL,
2426 __builtin_return_address(0));
2427}
2428
2429struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
2430 const void *caller)
2431{
2432 return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
2433 VMALLOC_START, VMALLOC_END,
2434 NUMA_NO_NODE, GFP_KERNEL, caller);
2435}
2436
2437/**
2438 * find_vm_area - find a continuous kernel virtual area
2439 * @addr: base address
2440 *
2441 * Search for the kernel VM area starting at @addr, and return it.
2442 * It is up to the caller to do all required locking to keep the returned
2443 * pointer valid.
2444 *
2445 * Return: the area descriptor on success or %NULL on failure.
2446 */
2447struct vm_struct *find_vm_area(const void *addr)
2448{
2449 struct vmap_area *va;
2450
2451 va = find_vmap_area((unsigned long)addr);
2452 if (!va)
2453 return NULL;
2454
2455 return va->vm;
2456}
2457
2458/**
2459 * remove_vm_area - find and remove a continuous kernel virtual area
2460 * @addr: base address
2461 *
2462 * Search for the kernel VM area starting at @addr, and remove it.
2463 * This function returns the found VM area, but using it is NOT safe
2464 * on SMP machines, except for its size or flags.
2465 *
2466 * Return: the area descriptor on success or %NULL on failure.
2467 */
2468struct vm_struct *remove_vm_area(const void *addr)
2469{
2470 struct vmap_area *va;
2471
2472 might_sleep();
2473
2474 spin_lock(&vmap_area_lock);
2475 va = __find_vmap_area((unsigned long)addr);
2476 if (va && va->vm) {
2477 struct vm_struct *vm = va->vm;
2478
2479 va->vm = NULL;
2480 spin_unlock(&vmap_area_lock);
2481
2482 kasan_free_shadow(vm);
2483 free_unmap_vmap_area(va);
2484
2485 return vm;
2486 }
2487
2488 spin_unlock(&vmap_area_lock);
2489 return NULL;
2490}
2491
2492static inline void set_area_direct_map(const struct vm_struct *area,
2493 int (*set_direct_map)(struct page *page))
2494{
2495 int i;
2496
2497 /* HUGE_VMALLOC passes small pages to set_direct_map */
2498 for (i = 0; i < area->nr_pages; i++)
2499 if (page_address(area->pages[i]))
2500 set_direct_map(area->pages[i]);
2501}
2502
2503/* Handle removing and resetting vm mappings related to the vm_struct. */
2504static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages)
2505{
2506 unsigned long start = ULONG_MAX, end = 0;
2507 unsigned int page_order = vm_area_page_order(area);
2508 int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;
2509 int flush_dmap = 0;
2510 int i;
2511
2512 remove_vm_area(area->addr);
2513
2514 /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */
2515 if (!flush_reset)
2516 return;
2517
2518 /*
2519 * If not deallocating pages, just do the flush of the VM area and
2520 * return.
2521 */
2522 if (!deallocate_pages) {
2523 vm_unmap_aliases();
2524 return;
2525 }
2526
2527 /*
2528 * If execution gets here, flush the vm mapping and reset the direct
2529 * map. Find the start and end range of the direct mappings to make sure
2530 * the vm_unmap_aliases() flush includes the direct map.
2531 */
2532 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
2533 unsigned long addr = (unsigned long)page_address(area->pages[i]);
2534 if (addr) {
2535 unsigned long page_size;
2536
2537 page_size = PAGE_SIZE << page_order;
2538 start = min(addr, start);
2539 end = max(addr + page_size, end);
2540 flush_dmap = 1;
2541 }
2542 }
2543
2544 /*
2545 * Set direct map to something invalid so that it won't be cached if
2546 * there are any accesses after the TLB flush, then flush the TLB and
2547 * reset the direct map permissions to the default.
2548 */
2549 set_area_direct_map(area, set_direct_map_invalid_noflush);
2550 _vm_unmap_aliases(start, end, flush_dmap);
2551 set_area_direct_map(area, set_direct_map_default_noflush);
2552}
2553
2554static void __vunmap(const void *addr, int deallocate_pages)
2555{
2556 struct vm_struct *area;
2557
2558 if (!addr)
2559 return;
2560
2561 if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
2562 addr))
2563 return;
2564
2565 area = find_vm_area(addr);
2566 if (unlikely(!area)) {
2567 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
2568 addr);
2569 return;
2570 }
2571
2572 debug_check_no_locks_freed(area->addr, get_vm_area_size(area));
2573 debug_check_no_obj_freed(area->addr, get_vm_area_size(area));
2574
2575 kasan_poison_vmalloc(area->addr, get_vm_area_size(area));
2576
2577 vm_remove_mappings(area, deallocate_pages);
2578
2579 if (deallocate_pages) {
2580 unsigned int page_order = vm_area_page_order(area);
2581 int i;
2582
2583 for (i = 0; i < area->nr_pages; i += 1U << page_order) {
2584 struct page *page = area->pages[i];
2585
2586 BUG_ON(!page);
2587 __free_pages(page, page_order);
2588 cond_resched();
2589 }
2590 atomic_long_sub(area->nr_pages, &nr_vmalloc_pages);
2591
2592 kvfree(area->pages);
2593 }
2594
2595 kfree(area);
2596}
2597
2598static inline void __vfree_deferred(const void *addr)
2599{
2600 /*
2601 * Use raw_cpu_ptr() because this can be called from preemptible
2602 * context. Preemption is absolutely fine here, because the llist_add()
2603 * implementation is lockless, so it works even if we are adding to
2604 * another cpu's list. schedule_work() should be fine with this too.
2605 */
2606 struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
2607
2608 if (llist_add((struct llist_node *)addr, &p->list))
2609 schedule_work(&p->wq);
2610}
2611
2612/**
2613 * vfree_atomic - release memory allocated by vmalloc()
2614 * @addr: memory base address
2615 *
2616 * This one is just like vfree() but can be called in any atomic context
2617 * except NMIs.
2618 */
2619void vfree_atomic(const void *addr)
2620{
2621 BUG_ON(in_nmi());
2622
2623 kmemleak_free(addr);
2624
2625 if (!addr)
2626 return;
2627 __vfree_deferred(addr);
2628}
2629
2630static void __vfree(const void *addr)
2631{
2632 if (unlikely(in_interrupt()))
2633 __vfree_deferred(addr);
2634 else
2635 __vunmap(addr, 1);
2636}
2637
2638/**
2639 * vfree - Release memory allocated by vmalloc()
2640 * @addr: Memory base address
2641 *
2642 * Free the virtually continuous memory area starting at @addr, as obtained
2643 * from one of the vmalloc() family of APIs. This will usually also free the
2644 * physical memory underlying the virtual allocation, but that memory is
2645 * reference counted, so it will not be freed until the last user goes away.
2646 *
2647 * If @addr is NULL, no operation is performed.
2648 *
2649 * Context:
2650 * May sleep if called *not* from interrupt context.
2651 * Must not be called in NMI context (strictly speaking, it could be
2652 * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
2653 * conventions for vfree() arch-dependent would be a really bad idea).
2654 */
2655void vfree(const void *addr)
2656{
2657 BUG_ON(in_nmi());
2658
2659 kmemleak_free(addr);
2660
2661 might_sleep_if(!in_interrupt());
2662
2663 if (!addr)
2664 return;
2665
2666 __vfree(addr);
2667}
2668EXPORT_SYMBOL(vfree);
2669
2670/**
2671 * vunmap - release virtual mapping obtained by vmap()
2672 * @addr: memory base address
2673 *
2674 * Free the virtually contiguous memory area starting at @addr,
2675 * which was created from the page array passed to vmap().
2676 *
2677 * Must not be called in interrupt context.
2678 */
2679void vunmap(const void *addr)
2680{
2681 BUG_ON(in_interrupt());
2682 might_sleep();
2683 if (addr)
2684 __vunmap(addr, 0);
2685}
2686EXPORT_SYMBOL(vunmap);
2687
2688/**
2689 * vmap - map an array of pages into virtually contiguous space
2690 * @pages: array of page pointers
2691 * @count: number of pages to map
2692 * @flags: vm_area->flags
2693 * @prot: page protection for the mapping
2694 *
2695 * Maps @count pages from @pages into contiguous kernel virtual space.
2696 * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
2697 * (which must be kmalloc or vmalloc memory) and one reference per pages in it
2698 * are transferred from the caller to vmap(), and will be freed / dropped when
2699 * vfree() is called on the return value.
2700 *
2701 * Return: the address of the area or %NULL on failure
2702 */
2703void *vmap(struct page **pages, unsigned int count,
2704 unsigned long flags, pgprot_t prot)
2705{
2706 struct vm_struct *area;
2707 unsigned long addr;
2708 unsigned long size; /* In bytes */
2709
2710 might_sleep();
2711
2712 if (count > totalram_pages())
2713 return NULL;
2714
2715 size = (unsigned long)count << PAGE_SHIFT;
2716 area = get_vm_area_caller(size, flags, __builtin_return_address(0));
2717 if (!area)
2718 return NULL;
2719
2720 addr = (unsigned long)area->addr;
2721 if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
2722 pages, PAGE_SHIFT) < 0) {
2723 vunmap(area->addr);
2724 return NULL;
2725 }
2726
2727 if (flags & VM_MAP_PUT_PAGES) {
2728 area->pages = pages;
2729 area->nr_pages = count;
2730 }
2731 return area->addr;
2732}
2733EXPORT_SYMBOL(vmap);
2734
2735#ifdef CONFIG_VMAP_PFN
2736struct vmap_pfn_data {
2737 unsigned long *pfns;
2738 pgprot_t prot;
2739 unsigned int idx;
2740};
2741
2742static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
2743{
2744 struct vmap_pfn_data *data = private;
2745
2746 if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx])))
2747 return -EINVAL;
2748 *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
2749 return 0;
2750}
2751
2752/**
2753 * vmap_pfn - map an array of PFNs into virtually contiguous space
2754 * @pfns: array of PFNs
2755 * @count: number of pages to map
2756 * @prot: page protection for the mapping
2757 *
2758 * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
2759 * the start address of the mapping.
2760 */
2761void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
2762{
2763 struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) };
2764 struct vm_struct *area;
2765
2766 area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP,
2767 __builtin_return_address(0));
2768 if (!area)
2769 return NULL;
2770 if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
2771 count * PAGE_SIZE, vmap_pfn_apply, &data)) {
2772 free_vm_area(area);
2773 return NULL;
2774 }
2775 return area->addr;
2776}
2777EXPORT_SYMBOL_GPL(vmap_pfn);
2778#endif /* CONFIG_VMAP_PFN */
2779
2780static inline unsigned int
2781vm_area_alloc_pages(gfp_t gfp, int nid,
2782 unsigned int order, unsigned long nr_pages, struct page **pages)
2783{
2784 unsigned int nr_allocated = 0;
2785
2786 /*
2787 * For order-0 pages we make use of bulk allocator, if
2788 * the page array is partly or not at all populated due
2789 * to fails, fallback to a single page allocator that is
2790 * more permissive.
2791 */
2792 if (!order)
2793 nr_allocated = alloc_pages_bulk_array_node(
2794 gfp, nid, nr_pages, pages);
2795 else
2796 /*
2797 * Compound pages required for remap_vmalloc_page if
2798 * high-order pages.
2799 */
2800 gfp |= __GFP_COMP;
2801
2802 /* High-order pages or fallback path if "bulk" fails. */
2803 while (nr_allocated < nr_pages) {
2804 struct page *page;
2805 int i;
2806
2807 page = alloc_pages_node(nid, gfp, order);
2808 if (unlikely(!page))
2809 break;
2810
2811 /*
2812 * Careful, we allocate and map page-order pages, but
2813 * tracking is done per PAGE_SIZE page so as to keep the
2814 * vm_struct APIs independent of the physical/mapped size.
2815 */
2816 for (i = 0; i < (1U << order); i++)
2817 pages[nr_allocated + i] = page + i;
2818
2819 if (gfpflags_allow_blocking(gfp))
2820 cond_resched();
2821
2822 nr_allocated += 1U << order;
2823 }
2824
2825 return nr_allocated;
2826}
2827
2828static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
2829 pgprot_t prot, unsigned int page_shift,
2830 int node)
2831{
2832 const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
2833 unsigned long addr = (unsigned long)area->addr;
2834 unsigned long size = get_vm_area_size(area);
2835 unsigned long array_size;
2836 unsigned int nr_small_pages = size >> PAGE_SHIFT;
2837 unsigned int page_order;
2838
2839 array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
2840 gfp_mask |= __GFP_NOWARN;
2841 if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
2842 gfp_mask |= __GFP_HIGHMEM;
2843
2844 /* Please note that the recursion is strictly bounded. */
2845 if (array_size > PAGE_SIZE) {
2846 area->pages = __vmalloc_node(array_size, 1, nested_gfp, node,
2847 area->caller);
2848 } else {
2849 area->pages = kmalloc_node(array_size, nested_gfp, node);
2850 }
2851
2852 if (!area->pages) {
2853 warn_alloc(gfp_mask, NULL,
2854 "vmalloc error: size %lu, failed to allocated page array size %lu",
2855 nr_small_pages * PAGE_SIZE, array_size);
2856 free_vm_area(area);
2857 return NULL;
2858 }
2859
2860 set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
2861 page_order = vm_area_page_order(area);
2862
2863 area->nr_pages = vm_area_alloc_pages(gfp_mask, node,
2864 page_order, nr_small_pages, area->pages);
2865
2866 atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
2867
2868 /*
2869 * If not enough pages were obtained to accomplish an
2870 * allocation request, free them via __vfree() if any.
2871 */
2872 if (area->nr_pages != nr_small_pages) {
2873 warn_alloc(gfp_mask, NULL,
2874 "vmalloc error: size %lu, page order %u, failed to allocate pages",
2875 area->nr_pages * PAGE_SIZE, page_order);
2876 goto fail;
2877 }
2878
2879 if (vmap_pages_range(addr, addr + size, prot, area->pages,
2880 page_shift) < 0) {
2881 warn_alloc(gfp_mask, NULL,
2882 "vmalloc error: size %lu, failed to map pages",
2883 area->nr_pages * PAGE_SIZE);
2884 goto fail;
2885 }
2886
2887 return area->addr;
2888
2889fail:
2890 __vfree(area->addr);
2891 return NULL;
2892}
2893
2894/**
2895 * __vmalloc_node_range - allocate virtually contiguous memory
2896 * @size: allocation size
2897 * @align: desired alignment
2898 * @start: vm area range start
2899 * @end: vm area range end
2900 * @gfp_mask: flags for the page level allocator
2901 * @prot: protection mask for the allocated pages
2902 * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD)
2903 * @node: node to use for allocation or NUMA_NO_NODE
2904 * @caller: caller's return address
2905 *
2906 * Allocate enough pages to cover @size from the page level
2907 * allocator with @gfp_mask flags. Map them into contiguous
2908 * kernel virtual space, using a pagetable protection of @prot.
2909 *
2910 * Return: the address of the area or %NULL on failure
2911 */
2912void *__vmalloc_node_range(unsigned long size, unsigned long align,
2913 unsigned long start, unsigned long end, gfp_t gfp_mask,
2914 pgprot_t prot, unsigned long vm_flags, int node,
2915 const void *caller)
2916{
2917 struct vm_struct *area;
2918 void *addr;
2919 unsigned long real_size = size;
2920 unsigned long real_align = align;
2921 unsigned int shift = PAGE_SHIFT;
2922
2923 if (WARN_ON_ONCE(!size))
2924 return NULL;
2925
2926 if ((size >> PAGE_SHIFT) > totalram_pages()) {
2927 warn_alloc(gfp_mask, NULL,
2928 "vmalloc error: size %lu, exceeds total pages",
2929 real_size);
2930 return NULL;
2931 }
2932
2933 if (vmap_allow_huge && !(vm_flags & VM_NO_HUGE_VMAP)) {
2934 unsigned long size_per_node;
2935
2936 /*
2937 * Try huge pages. Only try for PAGE_KERNEL allocations,
2938 * others like modules don't yet expect huge pages in
2939 * their allocations due to apply_to_page_range not
2940 * supporting them.
2941 */
2942
2943 size_per_node = size;
2944 if (node == NUMA_NO_NODE)
2945 size_per_node /= num_online_nodes();
2946 if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
2947 shift = PMD_SHIFT;
2948 else
2949 shift = arch_vmap_pte_supported_shift(size_per_node);
2950
2951 align = max(real_align, 1UL << shift);
2952 size = ALIGN(real_size, 1UL << shift);
2953 }
2954
2955again:
2956 area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
2957 VM_UNINITIALIZED | vm_flags, start, end, node,
2958 gfp_mask, caller);
2959 if (!area) {
2960 warn_alloc(gfp_mask, NULL,
2961 "vmalloc error: size %lu, vm_struct allocation failed",
2962 real_size);
2963 goto fail;
2964 }
2965
2966 addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
2967 if (!addr)
2968 goto fail;
2969
2970 /*
2971 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
2972 * flag. It means that vm_struct is not fully initialized.
2973 * Now, it is fully initialized, so remove this flag here.
2974 */
2975 clear_vm_uninitialized_flag(area);
2976
2977 size = PAGE_ALIGN(size);
2978 kmemleak_vmalloc(area, size, gfp_mask);
2979
2980 return addr;
2981
2982fail:
2983 if (shift > PAGE_SHIFT) {
2984 shift = PAGE_SHIFT;
2985 align = real_align;
2986 size = real_size;
2987 goto again;
2988 }
2989
2990 return NULL;
2991}
2992
2993/**
2994 * __vmalloc_node - allocate virtually contiguous memory
2995 * @size: allocation size
2996 * @align: desired alignment
2997 * @gfp_mask: flags for the page level allocator
2998 * @node: node to use for allocation or NUMA_NO_NODE
2999 * @caller: caller's return address
3000 *
3001 * Allocate enough pages to cover @size from the page level allocator with
3002 * @gfp_mask flags. Map them into contiguous kernel virtual space.
3003 *
3004 * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
3005 * and __GFP_NOFAIL are not supported
3006 *
3007 * Any use of gfp flags outside of GFP_KERNEL should be consulted
3008 * with mm people.
3009 *
3010 * Return: pointer to the allocated memory or %NULL on error
3011 */
3012void *__vmalloc_node(unsigned long size, unsigned long align,
3013 gfp_t gfp_mask, int node, const void *caller)
3014{
3015 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
3016 gfp_mask, PAGE_KERNEL, 0, node, caller);
3017}
3018/*
3019 * This is only for performance analysis of vmalloc and stress purpose.
3020 * It is required by vmalloc test module, therefore do not use it other
3021 * than that.
3022 */
3023#ifdef CONFIG_TEST_VMALLOC_MODULE
3024EXPORT_SYMBOL_GPL(__vmalloc_node);
3025#endif
3026
3027void *__vmalloc(unsigned long size, gfp_t gfp_mask)
3028{
3029 return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE,
3030 __builtin_return_address(0));
3031}
3032EXPORT_SYMBOL(__vmalloc);
3033
3034/**
3035 * vmalloc - allocate virtually contiguous memory
3036 * @size: allocation size
3037 *
3038 * Allocate enough pages to cover @size from the page level
3039 * allocator and map them into contiguous kernel virtual space.
3040 *
3041 * For tight control over page level allocator and protection flags
3042 * use __vmalloc() instead.
3043 *
3044 * Return: pointer to the allocated memory or %NULL on error
3045 */
3046void *vmalloc(unsigned long size)
3047{
3048 return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE,
3049 __builtin_return_address(0));
3050}
3051EXPORT_SYMBOL(vmalloc);
3052
3053/**
3054 * vmalloc_no_huge - allocate virtually contiguous memory using small pages
3055 * @size: allocation size
3056 *
3057 * Allocate enough non-huge pages to cover @size from the page level
3058 * allocator and map them into contiguous kernel virtual space.
3059 *
3060 * Return: pointer to the allocated memory or %NULL on error
3061 */
3062void *vmalloc_no_huge(unsigned long size)
3063{
3064 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
3065 GFP_KERNEL, PAGE_KERNEL, VM_NO_HUGE_VMAP,
3066 NUMA_NO_NODE, __builtin_return_address(0));
3067}
3068EXPORT_SYMBOL(vmalloc_no_huge);
3069
3070/**
3071 * vzalloc - allocate virtually contiguous memory with zero fill
3072 * @size: allocation size
3073 *
3074 * Allocate enough pages to cover @size from the page level
3075 * allocator and map them into contiguous kernel virtual space.
3076 * The memory allocated is set to zero.
3077 *
3078 * For tight control over page level allocator and protection flags
3079 * use __vmalloc() instead.
3080 *
3081 * Return: pointer to the allocated memory or %NULL on error
3082 */
3083void *vzalloc(unsigned long size)
3084{
3085 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE,
3086 __builtin_return_address(0));
3087}
3088EXPORT_SYMBOL(vzalloc);
3089
3090/**
3091 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
3092 * @size: allocation size
3093 *
3094 * The resulting memory area is zeroed so it can be mapped to userspace
3095 * without leaking data.
3096 *
3097 * Return: pointer to the allocated memory or %NULL on error
3098 */
3099void *vmalloc_user(unsigned long size)
3100{
3101 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3102 GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
3103 VM_USERMAP, NUMA_NO_NODE,
3104 __builtin_return_address(0));
3105}
3106EXPORT_SYMBOL(vmalloc_user);
3107
3108/**
3109 * vmalloc_node - allocate memory on a specific node
3110 * @size: allocation size
3111 * @node: numa node
3112 *
3113 * Allocate enough pages to cover @size from the page level
3114 * allocator and map them into contiguous kernel virtual space.
3115 *
3116 * For tight control over page level allocator and protection flags
3117 * use __vmalloc() instead.
3118 *
3119 * Return: pointer to the allocated memory or %NULL on error
3120 */
3121void *vmalloc_node(unsigned long size, int node)
3122{
3123 return __vmalloc_node(size, 1, GFP_KERNEL, node,
3124 __builtin_return_address(0));
3125}
3126EXPORT_SYMBOL(vmalloc_node);
3127
3128/**
3129 * vzalloc_node - allocate memory on a specific node with zero fill
3130 * @size: allocation size
3131 * @node: numa node
3132 *
3133 * Allocate enough pages to cover @size from the page level
3134 * allocator and map them into contiguous kernel virtual space.
3135 * The memory allocated is set to zero.
3136 *
3137 * Return: pointer to the allocated memory or %NULL on error
3138 */
3139void *vzalloc_node(unsigned long size, int node)
3140{
3141 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node,
3142 __builtin_return_address(0));
3143}
3144EXPORT_SYMBOL(vzalloc_node);
3145
3146#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
3147#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3148#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
3149#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
3150#else
3151/*
3152 * 64b systems should always have either DMA or DMA32 zones. For others
3153 * GFP_DMA32 should do the right thing and use the normal zone.
3154 */
3155#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
3156#endif
3157
3158/**
3159 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
3160 * @size: allocation size
3161 *
3162 * Allocate enough 32bit PA addressable pages to cover @size from the
3163 * page level allocator and map them into contiguous kernel virtual space.
3164 *
3165 * Return: pointer to the allocated memory or %NULL on error
3166 */
3167void *vmalloc_32(unsigned long size)
3168{
3169 return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE,
3170 __builtin_return_address(0));
3171}
3172EXPORT_SYMBOL(vmalloc_32);
3173
3174/**
3175 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
3176 * @size: allocation size
3177 *
3178 * The resulting memory area is 32bit addressable and zeroed so it can be
3179 * mapped to userspace without leaking data.
3180 *
3181 * Return: pointer to the allocated memory or %NULL on error
3182 */
3183void *vmalloc_32_user(unsigned long size)
3184{
3185 return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END,
3186 GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
3187 VM_USERMAP, NUMA_NO_NODE,
3188 __builtin_return_address(0));
3189}
3190EXPORT_SYMBOL(vmalloc_32_user);
3191
3192/*
3193 * small helper routine , copy contents to buf from addr.
3194 * If the page is not present, fill zero.
3195 */
3196
3197static int aligned_vread(char *buf, char *addr, unsigned long count)
3198{
3199 struct page *p;
3200 int copied = 0;
3201
3202 while (count) {
3203 unsigned long offset, length;
3204
3205 offset = offset_in_page(addr);
3206 length = PAGE_SIZE - offset;
3207 if (length > count)
3208 length = count;
3209 p = vmalloc_to_page(addr);
3210 /*
3211 * To do safe access to this _mapped_ area, we need
3212 * lock. But adding lock here means that we need to add
3213 * overhead of vmalloc()/vfree() calls for this _debug_
3214 * interface, rarely used. Instead of that, we'll use
3215 * kmap() and get small overhead in this access function.
3216 */
3217 if (p) {
3218 /* We can expect USER0 is not used -- see vread() */
3219 void *map = kmap_atomic(p);
3220 memcpy(buf, map + offset, length);
3221 kunmap_atomic(map);
3222 } else
3223 memset(buf, 0, length);
3224
3225 addr += length;
3226 buf += length;
3227 copied += length;
3228 count -= length;
3229 }
3230 return copied;
3231}
3232
3233/**
3234 * vread() - read vmalloc area in a safe way.
3235 * @buf: buffer for reading data
3236 * @addr: vm address.
3237 * @count: number of bytes to be read.
3238 *
3239 * This function checks that addr is a valid vmalloc'ed area, and
3240 * copy data from that area to a given buffer. If the given memory range
3241 * of [addr...addr+count) includes some valid address, data is copied to
3242 * proper area of @buf. If there are memory holes, they'll be zero-filled.
3243 * IOREMAP area is treated as memory hole and no copy is done.
3244 *
3245 * If [addr...addr+count) doesn't includes any intersects with alive
3246 * vm_struct area, returns 0. @buf should be kernel's buffer.
3247 *
3248 * Note: In usual ops, vread() is never necessary because the caller
3249 * should know vmalloc() area is valid and can use memcpy().
3250 * This is for routines which have to access vmalloc area without
3251 * any information, as /proc/kcore.
3252 *
3253 * Return: number of bytes for which addr and buf should be increased
3254 * (same number as @count) or %0 if [addr...addr+count) doesn't
3255 * include any intersection with valid vmalloc area
3256 */
3257long vread(char *buf, char *addr, unsigned long count)
3258{
3259 struct vmap_area *va;
3260 struct vm_struct *vm;
3261 char *vaddr, *buf_start = buf;
3262 unsigned long buflen = count;
3263 unsigned long n;
3264
3265 /* Don't allow overflow */
3266 if ((unsigned long) addr + count < count)
3267 count = -(unsigned long) addr;
3268
3269 spin_lock(&vmap_area_lock);
3270 va = __find_vmap_area((unsigned long)addr);
3271 if (!va)
3272 goto finished;
3273 list_for_each_entry_from(va, &vmap_area_list, list) {
3274 if (!count)
3275 break;
3276
3277 if (!va->vm)
3278 continue;
3279
3280 vm = va->vm;
3281 vaddr = (char *) vm->addr;
3282 if (addr >= vaddr + get_vm_area_size(vm))
3283 continue;
3284 while (addr < vaddr) {
3285 if (count == 0)
3286 goto finished;
3287 *buf = '\0';
3288 buf++;
3289 addr++;
3290 count--;
3291 }
3292 n = vaddr + get_vm_area_size(vm) - addr;
3293 if (n > count)
3294 n = count;
3295 if (!(vm->flags & VM_IOREMAP))
3296 aligned_vread(buf, addr, n);
3297 else /* IOREMAP area is treated as memory hole */
3298 memset(buf, 0, n);
3299 buf += n;
3300 addr += n;
3301 count -= n;
3302 }
3303finished:
3304 spin_unlock(&vmap_area_lock);
3305
3306 if (buf == buf_start)
3307 return 0;
3308 /* zero-fill memory holes */
3309 if (buf != buf_start + buflen)
3310 memset(buf, 0, buflen - (buf - buf_start));
3311
3312 return buflen;
3313}
3314
3315/**
3316 * remap_vmalloc_range_partial - map vmalloc pages to userspace
3317 * @vma: vma to cover
3318 * @uaddr: target user address to start at
3319 * @kaddr: virtual address of vmalloc kernel memory
3320 * @pgoff: offset from @kaddr to start at
3321 * @size: size of map area
3322 *
3323 * Returns: 0 for success, -Exxx on failure
3324 *
3325 * This function checks that @kaddr is a valid vmalloc'ed area,
3326 * and that it is big enough to cover the range starting at
3327 * @uaddr in @vma. Will return failure if that criteria isn't
3328 * met.
3329 *
3330 * Similar to remap_pfn_range() (see mm/memory.c)
3331 */
3332int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
3333 void *kaddr, unsigned long pgoff,
3334 unsigned long size)
3335{
3336 struct vm_struct *area;
3337 unsigned long off;
3338 unsigned long end_index;
3339
3340 if (check_shl_overflow(pgoff, PAGE_SHIFT, &off))
3341 return -EINVAL;
3342
3343 size = PAGE_ALIGN(size);
3344
3345 if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
3346 return -EINVAL;
3347
3348 area = find_vm_area(kaddr);
3349 if (!area)
3350 return -EINVAL;
3351
3352 if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
3353 return -EINVAL;
3354
3355 if (check_add_overflow(size, off, &end_index) ||
3356 end_index > get_vm_area_size(area))
3357 return -EINVAL;
3358 kaddr += off;
3359
3360 do {
3361 struct page *page = vmalloc_to_page(kaddr);
3362 int ret;
3363
3364 ret = vm_insert_page(vma, uaddr, page);
3365 if (ret)
3366 return ret;
3367
3368 uaddr += PAGE_SIZE;
3369 kaddr += PAGE_SIZE;
3370 size -= PAGE_SIZE;
3371 } while (size > 0);
3372
3373 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
3374
3375 return 0;
3376}
3377
3378/**
3379 * remap_vmalloc_range - map vmalloc pages to userspace
3380 * @vma: vma to cover (map full range of vma)
3381 * @addr: vmalloc memory
3382 * @pgoff: number of pages into addr before first page to map
3383 *
3384 * Returns: 0 for success, -Exxx on failure
3385 *
3386 * This function checks that addr is a valid vmalloc'ed area, and
3387 * that it is big enough to cover the vma. Will return failure if
3388 * that criteria isn't met.
3389 *
3390 * Similar to remap_pfn_range() (see mm/memory.c)
3391 */
3392int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
3393 unsigned long pgoff)
3394{
3395 return remap_vmalloc_range_partial(vma, vma->vm_start,
3396 addr, pgoff,
3397 vma->vm_end - vma->vm_start);
3398}
3399EXPORT_SYMBOL(remap_vmalloc_range);
3400
3401void free_vm_area(struct vm_struct *area)
3402{
3403 struct vm_struct *ret;
3404 ret = remove_vm_area(area->addr);
3405 BUG_ON(ret != area);
3406 kfree(area);
3407}
3408EXPORT_SYMBOL_GPL(free_vm_area);
3409
3410#ifdef CONFIG_SMP
3411static struct vmap_area *node_to_va(struct rb_node *n)
3412{
3413 return rb_entry_safe(n, struct vmap_area, rb_node);
3414}
3415
3416/**
3417 * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
3418 * @addr: target address
3419 *
3420 * Returns: vmap_area if it is found. If there is no such area
3421 * the first highest(reverse order) vmap_area is returned
3422 * i.e. va->va_start < addr && va->va_end < addr or NULL
3423 * if there are no any areas before @addr.
3424 */
3425static struct vmap_area *
3426pvm_find_va_enclose_addr(unsigned long addr)
3427{
3428 struct vmap_area *va, *tmp;
3429 struct rb_node *n;
3430
3431 n = free_vmap_area_root.rb_node;
3432 va = NULL;
3433
3434 while (n) {
3435 tmp = rb_entry(n, struct vmap_area, rb_node);
3436 if (tmp->va_start <= addr) {
3437 va = tmp;
3438 if (tmp->va_end >= addr)
3439 break;
3440
3441 n = n->rb_right;
3442 } else {
3443 n = n->rb_left;
3444 }
3445 }
3446
3447 return va;
3448}
3449
3450/**
3451 * pvm_determine_end_from_reverse - find the highest aligned address
3452 * of free block below VMALLOC_END
3453 * @va:
3454 * in - the VA we start the search(reverse order);
3455 * out - the VA with the highest aligned end address.
3456 * @align: alignment for required highest address
3457 *
3458 * Returns: determined end address within vmap_area
3459 */
3460static unsigned long
3461pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
3462{
3463 unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3464 unsigned long addr;
3465
3466 if (likely(*va)) {
3467 list_for_each_entry_from_reverse((*va),
3468 &free_vmap_area_list, list) {
3469 addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
3470 if ((*va)->va_start < addr)
3471 return addr;
3472 }
3473 }
3474
3475 return 0;
3476}
3477
3478/**
3479 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
3480 * @offsets: array containing offset of each area
3481 * @sizes: array containing size of each area
3482 * @nr_vms: the number of areas to allocate
3483 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
3484 *
3485 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
3486 * vm_structs on success, %NULL on failure
3487 *
3488 * Percpu allocator wants to use congruent vm areas so that it can
3489 * maintain the offsets among percpu areas. This function allocates
3490 * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to
3491 * be scattered pretty far, distance between two areas easily going up
3492 * to gigabytes. To avoid interacting with regular vmallocs, these
3493 * areas are allocated from top.
3494 *
3495 * Despite its complicated look, this allocator is rather simple. It
3496 * does everything top-down and scans free blocks from the end looking
3497 * for matching base. While scanning, if any of the areas do not fit the
3498 * base address is pulled down to fit the area. Scanning is repeated till
3499 * all the areas fit and then all necessary data structures are inserted
3500 * and the result is returned.
3501 */
3502struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
3503 const size_t *sizes, int nr_vms,
3504 size_t align)
3505{
3506 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
3507 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
3508 struct vmap_area **vas, *va;
3509 struct vm_struct **vms;
3510 int area, area2, last_area, term_area;
3511 unsigned long base, start, size, end, last_end, orig_start, orig_end;
3512 bool purged = false;
3513 enum fit_type type;
3514
3515 /* verify parameters and allocate data structures */
3516 BUG_ON(offset_in_page(align) || !is_power_of_2(align));
3517 for (last_area = 0, area = 0; area < nr_vms; area++) {
3518 start = offsets[area];
3519 end = start + sizes[area];
3520
3521 /* is everything aligned properly? */
3522 BUG_ON(!IS_ALIGNED(offsets[area], align));
3523 BUG_ON(!IS_ALIGNED(sizes[area], align));
3524
3525 /* detect the area with the highest address */
3526 if (start > offsets[last_area])
3527 last_area = area;
3528
3529 for (area2 = area + 1; area2 < nr_vms; area2++) {
3530 unsigned long start2 = offsets[area2];
3531 unsigned long end2 = start2 + sizes[area2];
3532
3533 BUG_ON(start2 < end && start < end2);
3534 }
3535 }
3536 last_end = offsets[last_area] + sizes[last_area];
3537
3538 if (vmalloc_end - vmalloc_start < last_end) {
3539 WARN_ON(true);
3540 return NULL;
3541 }
3542
3543 vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
3544 vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
3545 if (!vas || !vms)
3546 goto err_free2;
3547
3548 for (area = 0; area < nr_vms; area++) {
3549 vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
3550 vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
3551 if (!vas[area] || !vms[area])
3552 goto err_free;
3553 }
3554retry:
3555 spin_lock(&free_vmap_area_lock);
3556
3557 /* start scanning - we scan from the top, begin with the last area */
3558 area = term_area = last_area;
3559 start = offsets[area];
3560 end = start + sizes[area];
3561
3562 va = pvm_find_va_enclose_addr(vmalloc_end);
3563 base = pvm_determine_end_from_reverse(&va, align) - end;
3564
3565 while (true) {
3566 /*
3567 * base might have underflowed, add last_end before
3568 * comparing.
3569 */
3570 if (base + last_end < vmalloc_start + last_end)
3571 goto overflow;
3572
3573 /*
3574 * Fitting base has not been found.
3575 */
3576 if (va == NULL)
3577 goto overflow;
3578
3579 /*
3580 * If required width exceeds current VA block, move
3581 * base downwards and then recheck.
3582 */
3583 if (base + end > va->va_end) {
3584 base = pvm_determine_end_from_reverse(&va, align) - end;
3585 term_area = area;
3586 continue;
3587 }
3588
3589 /*
3590 * If this VA does not fit, move base downwards and recheck.
3591 */
3592 if (base + start < va->va_start) {
3593 va = node_to_va(rb_prev(&va->rb_node));
3594 base = pvm_determine_end_from_reverse(&va, align) - end;
3595 term_area = area;
3596 continue;
3597 }
3598
3599 /*
3600 * This area fits, move on to the previous one. If
3601 * the previous one is the terminal one, we're done.
3602 */
3603 area = (area + nr_vms - 1) % nr_vms;
3604 if (area == term_area)
3605 break;
3606
3607 start = offsets[area];
3608 end = start + sizes[area];
3609 va = pvm_find_va_enclose_addr(base + end);
3610 }
3611
3612 /* we've found a fitting base, insert all va's */
3613 for (area = 0; area < nr_vms; area++) {
3614 int ret;
3615
3616 start = base + offsets[area];
3617 size = sizes[area];
3618
3619 va = pvm_find_va_enclose_addr(start);
3620 if (WARN_ON_ONCE(va == NULL))
3621 /* It is a BUG(), but trigger recovery instead. */
3622 goto recovery;
3623
3624 type = classify_va_fit_type(va, start, size);
3625 if (WARN_ON_ONCE(type == NOTHING_FIT))
3626 /* It is a BUG(), but trigger recovery instead. */
3627 goto recovery;
3628
3629 ret = adjust_va_to_fit_type(va, start, size, type);
3630 if (unlikely(ret))
3631 goto recovery;
3632
3633 /* Allocated area. */
3634 va = vas[area];
3635 va->va_start = start;
3636 va->va_end = start + size;
3637 }
3638
3639 spin_unlock(&free_vmap_area_lock);
3640
3641 /* populate the kasan shadow space */
3642 for (area = 0; area < nr_vms; area++) {
3643 if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area]))
3644 goto err_free_shadow;
3645
3646 kasan_unpoison_vmalloc((void *)vas[area]->va_start,
3647 sizes[area]);
3648 }
3649
3650 /* insert all vm's */
3651 spin_lock(&vmap_area_lock);
3652 for (area = 0; area < nr_vms; area++) {
3653 insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list);
3654
3655 setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
3656 pcpu_get_vm_areas);
3657 }
3658 spin_unlock(&vmap_area_lock);
3659
3660 kfree(vas);
3661 return vms;
3662
3663recovery:
3664 /*
3665 * Remove previously allocated areas. There is no
3666 * need in removing these areas from the busy tree,
3667 * because they are inserted only on the final step
3668 * and when pcpu_get_vm_areas() is success.
3669 */
3670 while (area--) {
3671 orig_start = vas[area]->va_start;
3672 orig_end = vas[area]->va_end;
3673 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
3674 &free_vmap_area_list);
3675 if (va)
3676 kasan_release_vmalloc(orig_start, orig_end,
3677 va->va_start, va->va_end);
3678 vas[area] = NULL;
3679 }
3680
3681overflow:
3682 spin_unlock(&free_vmap_area_lock);
3683 if (!purged) {
3684 purge_vmap_area_lazy();
3685 purged = true;
3686
3687 /* Before "retry", check if we recover. */
3688 for (area = 0; area < nr_vms; area++) {
3689 if (vas[area])
3690 continue;
3691
3692 vas[area] = kmem_cache_zalloc(
3693 vmap_area_cachep, GFP_KERNEL);
3694 if (!vas[area])
3695 goto err_free;
3696 }
3697
3698 goto retry;
3699 }
3700
3701err_free:
3702 for (area = 0; area < nr_vms; area++) {
3703 if (vas[area])
3704 kmem_cache_free(vmap_area_cachep, vas[area]);
3705
3706 kfree(vms[area]);
3707 }
3708err_free2:
3709 kfree(vas);
3710 kfree(vms);
3711 return NULL;
3712
3713err_free_shadow:
3714 spin_lock(&free_vmap_area_lock);
3715 /*
3716 * We release all the vmalloc shadows, even the ones for regions that
3717 * hadn't been successfully added. This relies on kasan_release_vmalloc
3718 * being able to tolerate this case.
3719 */
3720 for (area = 0; area < nr_vms; area++) {
3721 orig_start = vas[area]->va_start;
3722 orig_end = vas[area]->va_end;
3723 va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
3724 &free_vmap_area_list);
3725 if (va)
3726 kasan_release_vmalloc(orig_start, orig_end,
3727 va->va_start, va->va_end);
3728 vas[area] = NULL;
3729 kfree(vms[area]);
3730 }
3731 spin_unlock(&free_vmap_area_lock);
3732 kfree(vas);
3733 kfree(vms);
3734 return NULL;
3735}
3736
3737/**
3738 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
3739 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
3740 * @nr_vms: the number of allocated areas
3741 *
3742 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
3743 */
3744void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
3745{
3746 int i;
3747
3748 for (i = 0; i < nr_vms; i++)
3749 free_vm_area(vms[i]);
3750 kfree(vms);
3751}
3752#endif /* CONFIG_SMP */
3753
3754#ifdef CONFIG_PRINTK
3755bool vmalloc_dump_obj(void *object)
3756{
3757 struct vm_struct *vm;
3758 void *objp = (void *)PAGE_ALIGN((unsigned long)object);
3759
3760 vm = find_vm_area(objp);
3761 if (!vm)
3762 return false;
3763 pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
3764 vm->nr_pages, (unsigned long)vm->addr, vm->caller);
3765 return true;
3766}
3767#endif
3768
3769#ifdef CONFIG_PROC_FS
3770static void *s_start(struct seq_file *m, loff_t *pos)
3771 __acquires(&vmap_purge_lock)
3772 __acquires(&vmap_area_lock)
3773{
3774 mutex_lock(&vmap_purge_lock);
3775 spin_lock(&vmap_area_lock);
3776
3777 return seq_list_start(&vmap_area_list, *pos);
3778}
3779
3780static void *s_next(struct seq_file *m, void *p, loff_t *pos)
3781{
3782 return seq_list_next(p, &vmap_area_list, pos);
3783}
3784
3785static void s_stop(struct seq_file *m, void *p)
3786 __releases(&vmap_area_lock)
3787 __releases(&vmap_purge_lock)
3788{
3789 spin_unlock(&vmap_area_lock);
3790 mutex_unlock(&vmap_purge_lock);
3791}
3792
3793static void show_numa_info(struct seq_file *m, struct vm_struct *v)
3794{
3795 if (IS_ENABLED(CONFIG_NUMA)) {
3796 unsigned int nr, *counters = m->private;
3797
3798 if (!counters)
3799 return;
3800
3801 if (v->flags & VM_UNINITIALIZED)
3802 return;
3803 /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
3804 smp_rmb();
3805
3806 memset(counters, 0, nr_node_ids * sizeof(unsigned int));
3807
3808 for (nr = 0; nr < v->nr_pages; nr++)
3809 counters[page_to_nid(v->pages[nr])]++;
3810
3811 for_each_node_state(nr, N_HIGH_MEMORY)
3812 if (counters[nr])
3813 seq_printf(m, " N%u=%u", nr, counters[nr]);
3814 }
3815}
3816
3817static void show_purge_info(struct seq_file *m)
3818{
3819 struct vmap_area *va;
3820
3821 spin_lock(&purge_vmap_area_lock);
3822 list_for_each_entry(va, &purge_vmap_area_list, list) {
3823 seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
3824 (void *)va->va_start, (void *)va->va_end,
3825 va->va_end - va->va_start);
3826 }
3827 spin_unlock(&purge_vmap_area_lock);
3828}
3829
3830static int s_show(struct seq_file *m, void *p)
3831{
3832 struct vmap_area *va;
3833 struct vm_struct *v;
3834
3835 va = list_entry(p, struct vmap_area, list);
3836
3837 /*
3838 * s_show can encounter race with remove_vm_area, !vm on behalf
3839 * of vmap area is being tear down or vm_map_ram allocation.
3840 */
3841 if (!va->vm) {
3842 seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
3843 (void *)va->va_start, (void *)va->va_end,
3844 va->va_end - va->va_start);
3845
3846 return 0;
3847 }
3848
3849 v = va->vm;
3850
3851 seq_printf(m, "0x%pK-0x%pK %7ld",
3852 v->addr, v->addr + v->size, v->size);
3853
3854 if (v->caller)
3855 seq_printf(m, " %pS", v->caller);
3856
3857 if (v->nr_pages)
3858 seq_printf(m, " pages=%d", v->nr_pages);
3859
3860 if (v->phys_addr)
3861 seq_printf(m, " phys=%pa", &v->phys_addr);
3862
3863 if (v->flags & VM_IOREMAP)
3864 seq_puts(m, " ioremap");
3865
3866 if (v->flags & VM_ALLOC)
3867 seq_puts(m, " vmalloc");
3868
3869 if (v->flags & VM_MAP)
3870 seq_puts(m, " vmap");
3871
3872 if (v->flags & VM_USERMAP)
3873 seq_puts(m, " user");
3874
3875 if (v->flags & VM_DMA_COHERENT)
3876 seq_puts(m, " dma-coherent");
3877
3878 if (is_vmalloc_addr(v->pages))
3879 seq_puts(m, " vpages");
3880
3881 show_numa_info(m, v);
3882 seq_putc(m, '\n');
3883
3884 /*
3885 * As a final step, dump "unpurged" areas.
3886 */
3887 if (list_is_last(&va->list, &vmap_area_list))
3888 show_purge_info(m);
3889
3890 return 0;
3891}
3892
3893static const struct seq_operations vmalloc_op = {
3894 .start = s_start,
3895 .next = s_next,
3896 .stop = s_stop,
3897 .show = s_show,
3898};
3899
3900static int __init proc_vmalloc_init(void)
3901{
3902 if (IS_ENABLED(CONFIG_NUMA))
3903 proc_create_seq_private("vmallocinfo", 0400, NULL,
3904 &vmalloc_op,
3905 nr_node_ids * sizeof(unsigned int), NULL);
3906 else
3907 proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
3908 return 0;
3909}
3910module_init(proc_vmalloc_init);
3911
3912#endif