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1 | /* | |
2 | * linux/mm/vmalloc.c | |
3 | * | |
4 | * Copyright (C) 1993 Linus Torvalds | |
5 | * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 | |
6 | * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000 | |
7 | * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002 | |
8 | * Numa awareness, Christoph Lameter, SGI, June 2005 | |
9 | */ | |
10 | ||
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/highmem.h> | |
15 | #include <linux/sched/signal.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/spinlock.h> | |
18 | #include <linux/interrupt.h> | |
19 | #include <linux/proc_fs.h> | |
20 | #include <linux/seq_file.h> | |
21 | #include <linux/debugobjects.h> | |
22 | #include <linux/kallsyms.h> | |
23 | #include <linux/list.h> | |
24 | #include <linux/notifier.h> | |
25 | #include <linux/rbtree.h> | |
26 | #include <linux/radix-tree.h> | |
27 | #include <linux/rcupdate.h> | |
28 | #include <linux/pfn.h> | |
29 | #include <linux/kmemleak.h> | |
30 | #include <linux/atomic.h> | |
31 | #include <linux/compiler.h> | |
32 | #include <linux/llist.h> | |
33 | #include <linux/bitops.h> | |
34 | ||
35 | #include <linux/uaccess.h> | |
36 | #include <asm/tlbflush.h> | |
37 | #include <asm/shmparam.h> | |
38 | ||
39 | #include "internal.h" | |
40 | ||
41 | struct vfree_deferred { | |
42 | struct llist_head list; | |
43 | struct work_struct wq; | |
44 | }; | |
45 | static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred); | |
46 | ||
47 | static void __vunmap(const void *, int); | |
48 | ||
49 | static void free_work(struct work_struct *w) | |
50 | { | |
51 | struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq); | |
52 | struct llist_node *llnode = llist_del_all(&p->list); | |
53 | while (llnode) { | |
54 | void *p = llnode; | |
55 | llnode = llist_next(llnode); | |
56 | __vunmap(p, 1); | |
57 | } | |
58 | } | |
59 | ||
60 | /*** Page table manipulation functions ***/ | |
61 | ||
62 | static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) | |
63 | { | |
64 | pte_t *pte; | |
65 | ||
66 | pte = pte_offset_kernel(pmd, addr); | |
67 | do { | |
68 | pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); | |
69 | WARN_ON(!pte_none(ptent) && !pte_present(ptent)); | |
70 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
71 | } | |
72 | ||
73 | static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end) | |
74 | { | |
75 | pmd_t *pmd; | |
76 | unsigned long next; | |
77 | ||
78 | pmd = pmd_offset(pud, addr); | |
79 | do { | |
80 | next = pmd_addr_end(addr, end); | |
81 | if (pmd_clear_huge(pmd)) | |
82 | continue; | |
83 | if (pmd_none_or_clear_bad(pmd)) | |
84 | continue; | |
85 | vunmap_pte_range(pmd, addr, next); | |
86 | } while (pmd++, addr = next, addr != end); | |
87 | } | |
88 | ||
89 | static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end) | |
90 | { | |
91 | pud_t *pud; | |
92 | unsigned long next; | |
93 | ||
94 | pud = pud_offset(p4d, addr); | |
95 | do { | |
96 | next = pud_addr_end(addr, end); | |
97 | if (pud_clear_huge(pud)) | |
98 | continue; | |
99 | if (pud_none_or_clear_bad(pud)) | |
100 | continue; | |
101 | vunmap_pmd_range(pud, addr, next); | |
102 | } while (pud++, addr = next, addr != end); | |
103 | } | |
104 | ||
105 | static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end) | |
106 | { | |
107 | p4d_t *p4d; | |
108 | unsigned long next; | |
109 | ||
110 | p4d = p4d_offset(pgd, addr); | |
111 | do { | |
112 | next = p4d_addr_end(addr, end); | |
113 | if (p4d_clear_huge(p4d)) | |
114 | continue; | |
115 | if (p4d_none_or_clear_bad(p4d)) | |
116 | continue; | |
117 | vunmap_pud_range(p4d, addr, next); | |
118 | } while (p4d++, addr = next, addr != end); | |
119 | } | |
120 | ||
121 | static void vunmap_page_range(unsigned long addr, unsigned long end) | |
122 | { | |
123 | pgd_t *pgd; | |
124 | unsigned long next; | |
125 | ||
126 | BUG_ON(addr >= end); | |
127 | pgd = pgd_offset_k(addr); | |
128 | do { | |
129 | next = pgd_addr_end(addr, end); | |
130 | if (pgd_none_or_clear_bad(pgd)) | |
131 | continue; | |
132 | vunmap_p4d_range(pgd, addr, next); | |
133 | } while (pgd++, addr = next, addr != end); | |
134 | } | |
135 | ||
136 | static int vmap_pte_range(pmd_t *pmd, unsigned long addr, | |
137 | unsigned long end, pgprot_t prot, struct page **pages, int *nr) | |
138 | { | |
139 | pte_t *pte; | |
140 | ||
141 | /* | |
142 | * nr is a running index into the array which helps higher level | |
143 | * callers keep track of where we're up to. | |
144 | */ | |
145 | ||
146 | pte = pte_alloc_kernel(pmd, addr); | |
147 | if (!pte) | |
148 | return -ENOMEM; | |
149 | do { | |
150 | struct page *page = pages[*nr]; | |
151 | ||
152 | if (WARN_ON(!pte_none(*pte))) | |
153 | return -EBUSY; | |
154 | if (WARN_ON(!page)) | |
155 | return -ENOMEM; | |
156 | set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); | |
157 | (*nr)++; | |
158 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
159 | return 0; | |
160 | } | |
161 | ||
162 | static int vmap_pmd_range(pud_t *pud, unsigned long addr, | |
163 | unsigned long end, pgprot_t prot, struct page **pages, int *nr) | |
164 | { | |
165 | pmd_t *pmd; | |
166 | unsigned long next; | |
167 | ||
168 | pmd = pmd_alloc(&init_mm, pud, addr); | |
169 | if (!pmd) | |
170 | return -ENOMEM; | |
171 | do { | |
172 | next = pmd_addr_end(addr, end); | |
173 | if (vmap_pte_range(pmd, addr, next, prot, pages, nr)) | |
174 | return -ENOMEM; | |
175 | } while (pmd++, addr = next, addr != end); | |
176 | return 0; | |
177 | } | |
178 | ||
179 | static int vmap_pud_range(p4d_t *p4d, unsigned long addr, | |
180 | unsigned long end, pgprot_t prot, struct page **pages, int *nr) | |
181 | { | |
182 | pud_t *pud; | |
183 | unsigned long next; | |
184 | ||
185 | pud = pud_alloc(&init_mm, p4d, addr); | |
186 | if (!pud) | |
187 | return -ENOMEM; | |
188 | do { | |
189 | next = pud_addr_end(addr, end); | |
190 | if (vmap_pmd_range(pud, addr, next, prot, pages, nr)) | |
191 | return -ENOMEM; | |
192 | } while (pud++, addr = next, addr != end); | |
193 | return 0; | |
194 | } | |
195 | ||
196 | static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, | |
197 | unsigned long end, pgprot_t prot, struct page **pages, int *nr) | |
198 | { | |
199 | p4d_t *p4d; | |
200 | unsigned long next; | |
201 | ||
202 | p4d = p4d_alloc(&init_mm, pgd, addr); | |
203 | if (!p4d) | |
204 | return -ENOMEM; | |
205 | do { | |
206 | next = p4d_addr_end(addr, end); | |
207 | if (vmap_pud_range(p4d, addr, next, prot, pages, nr)) | |
208 | return -ENOMEM; | |
209 | } while (p4d++, addr = next, addr != end); | |
210 | return 0; | |
211 | } | |
212 | ||
213 | /* | |
214 | * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and | |
215 | * will have pfns corresponding to the "pages" array. | |
216 | * | |
217 | * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N] | |
218 | */ | |
219 | static int vmap_page_range_noflush(unsigned long start, unsigned long end, | |
220 | pgprot_t prot, struct page **pages) | |
221 | { | |
222 | pgd_t *pgd; | |
223 | unsigned long next; | |
224 | unsigned long addr = start; | |
225 | int err = 0; | |
226 | int nr = 0; | |
227 | ||
228 | BUG_ON(addr >= end); | |
229 | pgd = pgd_offset_k(addr); | |
230 | do { | |
231 | next = pgd_addr_end(addr, end); | |
232 | err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr); | |
233 | if (err) | |
234 | return err; | |
235 | } while (pgd++, addr = next, addr != end); | |
236 | ||
237 | return nr; | |
238 | } | |
239 | ||
240 | static int vmap_page_range(unsigned long start, unsigned long end, | |
241 | pgprot_t prot, struct page **pages) | |
242 | { | |
243 | int ret; | |
244 | ||
245 | ret = vmap_page_range_noflush(start, end, prot, pages); | |
246 | flush_cache_vmap(start, end); | |
247 | return ret; | |
248 | } | |
249 | ||
250 | int is_vmalloc_or_module_addr(const void *x) | |
251 | { | |
252 | /* | |
253 | * ARM, x86-64 and sparc64 put modules in a special place, | |
254 | * and fall back on vmalloc() if that fails. Others | |
255 | * just put it in the vmalloc space. | |
256 | */ | |
257 | #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) | |
258 | unsigned long addr = (unsigned long)x; | |
259 | if (addr >= MODULES_VADDR && addr < MODULES_END) | |
260 | return 1; | |
261 | #endif | |
262 | return is_vmalloc_addr(x); | |
263 | } | |
264 | ||
265 | /* | |
266 | * Walk a vmap address to the struct page it maps. | |
267 | */ | |
268 | struct page *vmalloc_to_page(const void *vmalloc_addr) | |
269 | { | |
270 | unsigned long addr = (unsigned long) vmalloc_addr; | |
271 | struct page *page = NULL; | |
272 | pgd_t *pgd = pgd_offset_k(addr); | |
273 | p4d_t *p4d; | |
274 | pud_t *pud; | |
275 | pmd_t *pmd; | |
276 | pte_t *ptep, pte; | |
277 | ||
278 | /* | |
279 | * XXX we might need to change this if we add VIRTUAL_BUG_ON for | |
280 | * architectures that do not vmalloc module space | |
281 | */ | |
282 | VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr)); | |
283 | ||
284 | if (pgd_none(*pgd)) | |
285 | return NULL; | |
286 | p4d = p4d_offset(pgd, addr); | |
287 | if (p4d_none(*p4d)) | |
288 | return NULL; | |
289 | pud = pud_offset(p4d, addr); | |
290 | ||
291 | /* | |
292 | * Don't dereference bad PUD or PMD (below) entries. This will also | |
293 | * identify huge mappings, which we may encounter on architectures | |
294 | * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be | |
295 | * identified as vmalloc addresses by is_vmalloc_addr(), but are | |
296 | * not [unambiguously] associated with a struct page, so there is | |
297 | * no correct value to return for them. | |
298 | */ | |
299 | WARN_ON_ONCE(pud_bad(*pud)); | |
300 | if (pud_none(*pud) || pud_bad(*pud)) | |
301 | return NULL; | |
302 | pmd = pmd_offset(pud, addr); | |
303 | WARN_ON_ONCE(pmd_bad(*pmd)); | |
304 | if (pmd_none(*pmd) || pmd_bad(*pmd)) | |
305 | return NULL; | |
306 | ||
307 | ptep = pte_offset_map(pmd, addr); | |
308 | pte = *ptep; | |
309 | if (pte_present(pte)) | |
310 | page = pte_page(pte); | |
311 | pte_unmap(ptep); | |
312 | return page; | |
313 | } | |
314 | EXPORT_SYMBOL(vmalloc_to_page); | |
315 | ||
316 | /* | |
317 | * Map a vmalloc()-space virtual address to the physical page frame number. | |
318 | */ | |
319 | unsigned long vmalloc_to_pfn(const void *vmalloc_addr) | |
320 | { | |
321 | return page_to_pfn(vmalloc_to_page(vmalloc_addr)); | |
322 | } | |
323 | EXPORT_SYMBOL(vmalloc_to_pfn); | |
324 | ||
325 | ||
326 | /*** Global kva allocator ***/ | |
327 | ||
328 | #define VM_LAZY_FREE 0x02 | |
329 | #define VM_VM_AREA 0x04 | |
330 | ||
331 | static DEFINE_SPINLOCK(vmap_area_lock); | |
332 | /* Export for kexec only */ | |
333 | LIST_HEAD(vmap_area_list); | |
334 | static LLIST_HEAD(vmap_purge_list); | |
335 | static struct rb_root vmap_area_root = RB_ROOT; | |
336 | ||
337 | /* The vmap cache globals are protected by vmap_area_lock */ | |
338 | static struct rb_node *free_vmap_cache; | |
339 | static unsigned long cached_hole_size; | |
340 | static unsigned long cached_vstart; | |
341 | static unsigned long cached_align; | |
342 | ||
343 | static unsigned long vmap_area_pcpu_hole; | |
344 | ||
345 | static struct vmap_area *__find_vmap_area(unsigned long addr) | |
346 | { | |
347 | struct rb_node *n = vmap_area_root.rb_node; | |
348 | ||
349 | while (n) { | |
350 | struct vmap_area *va; | |
351 | ||
352 | va = rb_entry(n, struct vmap_area, rb_node); | |
353 | if (addr < va->va_start) | |
354 | n = n->rb_left; | |
355 | else if (addr >= va->va_end) | |
356 | n = n->rb_right; | |
357 | else | |
358 | return va; | |
359 | } | |
360 | ||
361 | return NULL; | |
362 | } | |
363 | ||
364 | static void __insert_vmap_area(struct vmap_area *va) | |
365 | { | |
366 | struct rb_node **p = &vmap_area_root.rb_node; | |
367 | struct rb_node *parent = NULL; | |
368 | struct rb_node *tmp; | |
369 | ||
370 | while (*p) { | |
371 | struct vmap_area *tmp_va; | |
372 | ||
373 | parent = *p; | |
374 | tmp_va = rb_entry(parent, struct vmap_area, rb_node); | |
375 | if (va->va_start < tmp_va->va_end) | |
376 | p = &(*p)->rb_left; | |
377 | else if (va->va_end > tmp_va->va_start) | |
378 | p = &(*p)->rb_right; | |
379 | else | |
380 | BUG(); | |
381 | } | |
382 | ||
383 | rb_link_node(&va->rb_node, parent, p); | |
384 | rb_insert_color(&va->rb_node, &vmap_area_root); | |
385 | ||
386 | /* address-sort this list */ | |
387 | tmp = rb_prev(&va->rb_node); | |
388 | if (tmp) { | |
389 | struct vmap_area *prev; | |
390 | prev = rb_entry(tmp, struct vmap_area, rb_node); | |
391 | list_add_rcu(&va->list, &prev->list); | |
392 | } else | |
393 | list_add_rcu(&va->list, &vmap_area_list); | |
394 | } | |
395 | ||
396 | static void purge_vmap_area_lazy(void); | |
397 | ||
398 | static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); | |
399 | ||
400 | /* | |
401 | * Allocate a region of KVA of the specified size and alignment, within the | |
402 | * vstart and vend. | |
403 | */ | |
404 | static struct vmap_area *alloc_vmap_area(unsigned long size, | |
405 | unsigned long align, | |
406 | unsigned long vstart, unsigned long vend, | |
407 | int node, gfp_t gfp_mask) | |
408 | { | |
409 | struct vmap_area *va; | |
410 | struct rb_node *n; | |
411 | unsigned long addr; | |
412 | int purged = 0; | |
413 | struct vmap_area *first; | |
414 | ||
415 | BUG_ON(!size); | |
416 | BUG_ON(offset_in_page(size)); | |
417 | BUG_ON(!is_power_of_2(align)); | |
418 | ||
419 | might_sleep(); | |
420 | ||
421 | va = kmalloc_node(sizeof(struct vmap_area), | |
422 | gfp_mask & GFP_RECLAIM_MASK, node); | |
423 | if (unlikely(!va)) | |
424 | return ERR_PTR(-ENOMEM); | |
425 | ||
426 | /* | |
427 | * Only scan the relevant parts containing pointers to other objects | |
428 | * to avoid false negatives. | |
429 | */ | |
430 | kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK); | |
431 | ||
432 | retry: | |
433 | spin_lock(&vmap_area_lock); | |
434 | /* | |
435 | * Invalidate cache if we have more permissive parameters. | |
436 | * cached_hole_size notes the largest hole noticed _below_ | |
437 | * the vmap_area cached in free_vmap_cache: if size fits | |
438 | * into that hole, we want to scan from vstart to reuse | |
439 | * the hole instead of allocating above free_vmap_cache. | |
440 | * Note that __free_vmap_area may update free_vmap_cache | |
441 | * without updating cached_hole_size or cached_align. | |
442 | */ | |
443 | if (!free_vmap_cache || | |
444 | size < cached_hole_size || | |
445 | vstart < cached_vstart || | |
446 | align < cached_align) { | |
447 | nocache: | |
448 | cached_hole_size = 0; | |
449 | free_vmap_cache = NULL; | |
450 | } | |
451 | /* record if we encounter less permissive parameters */ | |
452 | cached_vstart = vstart; | |
453 | cached_align = align; | |
454 | ||
455 | /* find starting point for our search */ | |
456 | if (free_vmap_cache) { | |
457 | first = rb_entry(free_vmap_cache, struct vmap_area, rb_node); | |
458 | addr = ALIGN(first->va_end, align); | |
459 | if (addr < vstart) | |
460 | goto nocache; | |
461 | if (addr + size < addr) | |
462 | goto overflow; | |
463 | ||
464 | } else { | |
465 | addr = ALIGN(vstart, align); | |
466 | if (addr + size < addr) | |
467 | goto overflow; | |
468 | ||
469 | n = vmap_area_root.rb_node; | |
470 | first = NULL; | |
471 | ||
472 | while (n) { | |
473 | struct vmap_area *tmp; | |
474 | tmp = rb_entry(n, struct vmap_area, rb_node); | |
475 | if (tmp->va_end >= addr) { | |
476 | first = tmp; | |
477 | if (tmp->va_start <= addr) | |
478 | break; | |
479 | n = n->rb_left; | |
480 | } else | |
481 | n = n->rb_right; | |
482 | } | |
483 | ||
484 | if (!first) | |
485 | goto found; | |
486 | } | |
487 | ||
488 | /* from the starting point, walk areas until a suitable hole is found */ | |
489 | while (addr + size > first->va_start && addr + size <= vend) { | |
490 | if (addr + cached_hole_size < first->va_start) | |
491 | cached_hole_size = first->va_start - addr; | |
492 | addr = ALIGN(first->va_end, align); | |
493 | if (addr + size < addr) | |
494 | goto overflow; | |
495 | ||
496 | if (list_is_last(&first->list, &vmap_area_list)) | |
497 | goto found; | |
498 | ||
499 | first = list_next_entry(first, list); | |
500 | } | |
501 | ||
502 | found: | |
503 | if (addr + size > vend) | |
504 | goto overflow; | |
505 | ||
506 | va->va_start = addr; | |
507 | va->va_end = addr + size; | |
508 | va->flags = 0; | |
509 | __insert_vmap_area(va); | |
510 | free_vmap_cache = &va->rb_node; | |
511 | spin_unlock(&vmap_area_lock); | |
512 | ||
513 | BUG_ON(!IS_ALIGNED(va->va_start, align)); | |
514 | BUG_ON(va->va_start < vstart); | |
515 | BUG_ON(va->va_end > vend); | |
516 | ||
517 | return va; | |
518 | ||
519 | overflow: | |
520 | spin_unlock(&vmap_area_lock); | |
521 | if (!purged) { | |
522 | purge_vmap_area_lazy(); | |
523 | purged = 1; | |
524 | goto retry; | |
525 | } | |
526 | ||
527 | if (gfpflags_allow_blocking(gfp_mask)) { | |
528 | unsigned long freed = 0; | |
529 | blocking_notifier_call_chain(&vmap_notify_list, 0, &freed); | |
530 | if (freed > 0) { | |
531 | purged = 0; | |
532 | goto retry; | |
533 | } | |
534 | } | |
535 | ||
536 | if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) | |
537 | pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n", | |
538 | size); | |
539 | kfree(va); | |
540 | return ERR_PTR(-EBUSY); | |
541 | } | |
542 | ||
543 | int register_vmap_purge_notifier(struct notifier_block *nb) | |
544 | { | |
545 | return blocking_notifier_chain_register(&vmap_notify_list, nb); | |
546 | } | |
547 | EXPORT_SYMBOL_GPL(register_vmap_purge_notifier); | |
548 | ||
549 | int unregister_vmap_purge_notifier(struct notifier_block *nb) | |
550 | { | |
551 | return blocking_notifier_chain_unregister(&vmap_notify_list, nb); | |
552 | } | |
553 | EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier); | |
554 | ||
555 | static void __free_vmap_area(struct vmap_area *va) | |
556 | { | |
557 | BUG_ON(RB_EMPTY_NODE(&va->rb_node)); | |
558 | ||
559 | if (free_vmap_cache) { | |
560 | if (va->va_end < cached_vstart) { | |
561 | free_vmap_cache = NULL; | |
562 | } else { | |
563 | struct vmap_area *cache; | |
564 | cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node); | |
565 | if (va->va_start <= cache->va_start) { | |
566 | free_vmap_cache = rb_prev(&va->rb_node); | |
567 | /* | |
568 | * We don't try to update cached_hole_size or | |
569 | * cached_align, but it won't go very wrong. | |
570 | */ | |
571 | } | |
572 | } | |
573 | } | |
574 | rb_erase(&va->rb_node, &vmap_area_root); | |
575 | RB_CLEAR_NODE(&va->rb_node); | |
576 | list_del_rcu(&va->list); | |
577 | ||
578 | /* | |
579 | * Track the highest possible candidate for pcpu area | |
580 | * allocation. Areas outside of vmalloc area can be returned | |
581 | * here too, consider only end addresses which fall inside | |
582 | * vmalloc area proper. | |
583 | */ | |
584 | if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END) | |
585 | vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end); | |
586 | ||
587 | kfree_rcu(va, rcu_head); | |
588 | } | |
589 | ||
590 | /* | |
591 | * Free a region of KVA allocated by alloc_vmap_area | |
592 | */ | |
593 | static void free_vmap_area(struct vmap_area *va) | |
594 | { | |
595 | spin_lock(&vmap_area_lock); | |
596 | __free_vmap_area(va); | |
597 | spin_unlock(&vmap_area_lock); | |
598 | } | |
599 | ||
600 | /* | |
601 | * Clear the pagetable entries of a given vmap_area | |
602 | */ | |
603 | static void unmap_vmap_area(struct vmap_area *va) | |
604 | { | |
605 | vunmap_page_range(va->va_start, va->va_end); | |
606 | } | |
607 | ||
608 | static void vmap_debug_free_range(unsigned long start, unsigned long end) | |
609 | { | |
610 | /* | |
611 | * Unmap page tables and force a TLB flush immediately if pagealloc | |
612 | * debugging is enabled. This catches use after free bugs similarly to | |
613 | * those in linear kernel virtual address space after a page has been | |
614 | * freed. | |
615 | * | |
616 | * All the lazy freeing logic is still retained, in order to minimise | |
617 | * intrusiveness of this debugging feature. | |
618 | * | |
619 | * This is going to be *slow* (linear kernel virtual address debugging | |
620 | * doesn't do a broadcast TLB flush so it is a lot faster). | |
621 | */ | |
622 | if (debug_pagealloc_enabled()) { | |
623 | vunmap_page_range(start, end); | |
624 | flush_tlb_kernel_range(start, end); | |
625 | } | |
626 | } | |
627 | ||
628 | /* | |
629 | * lazy_max_pages is the maximum amount of virtual address space we gather up | |
630 | * before attempting to purge with a TLB flush. | |
631 | * | |
632 | * There is a tradeoff here: a larger number will cover more kernel page tables | |
633 | * and take slightly longer to purge, but it will linearly reduce the number of | |
634 | * global TLB flushes that must be performed. It would seem natural to scale | |
635 | * this number up linearly with the number of CPUs (because vmapping activity | |
636 | * could also scale linearly with the number of CPUs), however it is likely | |
637 | * that in practice, workloads might be constrained in other ways that mean | |
638 | * vmap activity will not scale linearly with CPUs. Also, I want to be | |
639 | * conservative and not introduce a big latency on huge systems, so go with | |
640 | * a less aggressive log scale. It will still be an improvement over the old | |
641 | * code, and it will be simple to change the scale factor if we find that it | |
642 | * becomes a problem on bigger systems. | |
643 | */ | |
644 | static unsigned long lazy_max_pages(void) | |
645 | { | |
646 | unsigned int log; | |
647 | ||
648 | log = fls(num_online_cpus()); | |
649 | ||
650 | return log * (32UL * 1024 * 1024 / PAGE_SIZE); | |
651 | } | |
652 | ||
653 | static atomic_t vmap_lazy_nr = ATOMIC_INIT(0); | |
654 | ||
655 | /* | |
656 | * Serialize vmap purging. There is no actual criticial section protected | |
657 | * by this look, but we want to avoid concurrent calls for performance | |
658 | * reasons and to make the pcpu_get_vm_areas more deterministic. | |
659 | */ | |
660 | static DEFINE_MUTEX(vmap_purge_lock); | |
661 | ||
662 | /* for per-CPU blocks */ | |
663 | static void purge_fragmented_blocks_allcpus(void); | |
664 | ||
665 | /* | |
666 | * called before a call to iounmap() if the caller wants vm_area_struct's | |
667 | * immediately freed. | |
668 | */ | |
669 | void set_iounmap_nonlazy(void) | |
670 | { | |
671 | atomic_set(&vmap_lazy_nr, lazy_max_pages()+1); | |
672 | } | |
673 | ||
674 | /* | |
675 | * Purges all lazily-freed vmap areas. | |
676 | */ | |
677 | static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) | |
678 | { | |
679 | struct llist_node *valist; | |
680 | struct vmap_area *va; | |
681 | struct vmap_area *n_va; | |
682 | bool do_free = false; | |
683 | ||
684 | lockdep_assert_held(&vmap_purge_lock); | |
685 | ||
686 | valist = llist_del_all(&vmap_purge_list); | |
687 | llist_for_each_entry(va, valist, purge_list) { | |
688 | if (va->va_start < start) | |
689 | start = va->va_start; | |
690 | if (va->va_end > end) | |
691 | end = va->va_end; | |
692 | do_free = true; | |
693 | } | |
694 | ||
695 | if (!do_free) | |
696 | return false; | |
697 | ||
698 | flush_tlb_kernel_range(start, end); | |
699 | ||
700 | spin_lock(&vmap_area_lock); | |
701 | llist_for_each_entry_safe(va, n_va, valist, purge_list) { | |
702 | int nr = (va->va_end - va->va_start) >> PAGE_SHIFT; | |
703 | ||
704 | __free_vmap_area(va); | |
705 | atomic_sub(nr, &vmap_lazy_nr); | |
706 | cond_resched_lock(&vmap_area_lock); | |
707 | } | |
708 | spin_unlock(&vmap_area_lock); | |
709 | return true; | |
710 | } | |
711 | ||
712 | /* | |
713 | * Kick off a purge of the outstanding lazy areas. Don't bother if somebody | |
714 | * is already purging. | |
715 | */ | |
716 | static void try_purge_vmap_area_lazy(void) | |
717 | { | |
718 | if (mutex_trylock(&vmap_purge_lock)) { | |
719 | __purge_vmap_area_lazy(ULONG_MAX, 0); | |
720 | mutex_unlock(&vmap_purge_lock); | |
721 | } | |
722 | } | |
723 | ||
724 | /* | |
725 | * Kick off a purge of the outstanding lazy areas. | |
726 | */ | |
727 | static void purge_vmap_area_lazy(void) | |
728 | { | |
729 | mutex_lock(&vmap_purge_lock); | |
730 | purge_fragmented_blocks_allcpus(); | |
731 | __purge_vmap_area_lazy(ULONG_MAX, 0); | |
732 | mutex_unlock(&vmap_purge_lock); | |
733 | } | |
734 | ||
735 | /* | |
736 | * Free a vmap area, caller ensuring that the area has been unmapped | |
737 | * and flush_cache_vunmap had been called for the correct range | |
738 | * previously. | |
739 | */ | |
740 | static void free_vmap_area_noflush(struct vmap_area *va) | |
741 | { | |
742 | int nr_lazy; | |
743 | ||
744 | nr_lazy = atomic_add_return((va->va_end - va->va_start) >> PAGE_SHIFT, | |
745 | &vmap_lazy_nr); | |
746 | ||
747 | /* After this point, we may free va at any time */ | |
748 | llist_add(&va->purge_list, &vmap_purge_list); | |
749 | ||
750 | if (unlikely(nr_lazy > lazy_max_pages())) | |
751 | try_purge_vmap_area_lazy(); | |
752 | } | |
753 | ||
754 | /* | |
755 | * Free and unmap a vmap area | |
756 | */ | |
757 | static void free_unmap_vmap_area(struct vmap_area *va) | |
758 | { | |
759 | flush_cache_vunmap(va->va_start, va->va_end); | |
760 | unmap_vmap_area(va); | |
761 | free_vmap_area_noflush(va); | |
762 | } | |
763 | ||
764 | static struct vmap_area *find_vmap_area(unsigned long addr) | |
765 | { | |
766 | struct vmap_area *va; | |
767 | ||
768 | spin_lock(&vmap_area_lock); | |
769 | va = __find_vmap_area(addr); | |
770 | spin_unlock(&vmap_area_lock); | |
771 | ||
772 | return va; | |
773 | } | |
774 | ||
775 | /*** Per cpu kva allocator ***/ | |
776 | ||
777 | /* | |
778 | * vmap space is limited especially on 32 bit architectures. Ensure there is | |
779 | * room for at least 16 percpu vmap blocks per CPU. | |
780 | */ | |
781 | /* | |
782 | * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able | |
783 | * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess | |
784 | * instead (we just need a rough idea) | |
785 | */ | |
786 | #if BITS_PER_LONG == 32 | |
787 | #define VMALLOC_SPACE (128UL*1024*1024) | |
788 | #else | |
789 | #define VMALLOC_SPACE (128UL*1024*1024*1024) | |
790 | #endif | |
791 | ||
792 | #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE) | |
793 | #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */ | |
794 | #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */ | |
795 | #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2) | |
796 | #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */ | |
797 | #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */ | |
798 | #define VMAP_BBMAP_BITS \ | |
799 | VMAP_MIN(VMAP_BBMAP_BITS_MAX, \ | |
800 | VMAP_MAX(VMAP_BBMAP_BITS_MIN, \ | |
801 | VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16)) | |
802 | ||
803 | #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) | |
804 | ||
805 | static bool vmap_initialized __read_mostly = false; | |
806 | ||
807 | struct vmap_block_queue { | |
808 | spinlock_t lock; | |
809 | struct list_head free; | |
810 | }; | |
811 | ||
812 | struct vmap_block { | |
813 | spinlock_t lock; | |
814 | struct vmap_area *va; | |
815 | unsigned long free, dirty; | |
816 | unsigned long dirty_min, dirty_max; /*< dirty range */ | |
817 | struct list_head free_list; | |
818 | struct rcu_head rcu_head; | |
819 | struct list_head purge; | |
820 | }; | |
821 | ||
822 | /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */ | |
823 | static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue); | |
824 | ||
825 | /* | |
826 | * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block | |
827 | * in the free path. Could get rid of this if we change the API to return a | |
828 | * "cookie" from alloc, to be passed to free. But no big deal yet. | |
829 | */ | |
830 | static DEFINE_SPINLOCK(vmap_block_tree_lock); | |
831 | static RADIX_TREE(vmap_block_tree, GFP_ATOMIC); | |
832 | ||
833 | /* | |
834 | * We should probably have a fallback mechanism to allocate virtual memory | |
835 | * out of partially filled vmap blocks. However vmap block sizing should be | |
836 | * fairly reasonable according to the vmalloc size, so it shouldn't be a | |
837 | * big problem. | |
838 | */ | |
839 | ||
840 | static unsigned long addr_to_vb_idx(unsigned long addr) | |
841 | { | |
842 | addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1); | |
843 | addr /= VMAP_BLOCK_SIZE; | |
844 | return addr; | |
845 | } | |
846 | ||
847 | static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) | |
848 | { | |
849 | unsigned long addr; | |
850 | ||
851 | addr = va_start + (pages_off << PAGE_SHIFT); | |
852 | BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start)); | |
853 | return (void *)addr; | |
854 | } | |
855 | ||
856 | /** | |
857 | * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this | |
858 | * block. Of course pages number can't exceed VMAP_BBMAP_BITS | |
859 | * @order: how many 2^order pages should be occupied in newly allocated block | |
860 | * @gfp_mask: flags for the page level allocator | |
861 | * | |
862 | * Returns: virtual address in a newly allocated block or ERR_PTR(-errno) | |
863 | */ | |
864 | static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) | |
865 | { | |
866 | struct vmap_block_queue *vbq; | |
867 | struct vmap_block *vb; | |
868 | struct vmap_area *va; | |
869 | unsigned long vb_idx; | |
870 | int node, err; | |
871 | void *vaddr; | |
872 | ||
873 | node = numa_node_id(); | |
874 | ||
875 | vb = kmalloc_node(sizeof(struct vmap_block), | |
876 | gfp_mask & GFP_RECLAIM_MASK, node); | |
877 | if (unlikely(!vb)) | |
878 | return ERR_PTR(-ENOMEM); | |
879 | ||
880 | va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, | |
881 | VMALLOC_START, VMALLOC_END, | |
882 | node, gfp_mask); | |
883 | if (IS_ERR(va)) { | |
884 | kfree(vb); | |
885 | return ERR_CAST(va); | |
886 | } | |
887 | ||
888 | err = radix_tree_preload(gfp_mask); | |
889 | if (unlikely(err)) { | |
890 | kfree(vb); | |
891 | free_vmap_area(va); | |
892 | return ERR_PTR(err); | |
893 | } | |
894 | ||
895 | vaddr = vmap_block_vaddr(va->va_start, 0); | |
896 | spin_lock_init(&vb->lock); | |
897 | vb->va = va; | |
898 | /* At least something should be left free */ | |
899 | BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); | |
900 | vb->free = VMAP_BBMAP_BITS - (1UL << order); | |
901 | vb->dirty = 0; | |
902 | vb->dirty_min = VMAP_BBMAP_BITS; | |
903 | vb->dirty_max = 0; | |
904 | INIT_LIST_HEAD(&vb->free_list); | |
905 | ||
906 | vb_idx = addr_to_vb_idx(va->va_start); | |
907 | spin_lock(&vmap_block_tree_lock); | |
908 | err = radix_tree_insert(&vmap_block_tree, vb_idx, vb); | |
909 | spin_unlock(&vmap_block_tree_lock); | |
910 | BUG_ON(err); | |
911 | radix_tree_preload_end(); | |
912 | ||
913 | vbq = &get_cpu_var(vmap_block_queue); | |
914 | spin_lock(&vbq->lock); | |
915 | list_add_tail_rcu(&vb->free_list, &vbq->free); | |
916 | spin_unlock(&vbq->lock); | |
917 | put_cpu_var(vmap_block_queue); | |
918 | ||
919 | return vaddr; | |
920 | } | |
921 | ||
922 | static void free_vmap_block(struct vmap_block *vb) | |
923 | { | |
924 | struct vmap_block *tmp; | |
925 | unsigned long vb_idx; | |
926 | ||
927 | vb_idx = addr_to_vb_idx(vb->va->va_start); | |
928 | spin_lock(&vmap_block_tree_lock); | |
929 | tmp = radix_tree_delete(&vmap_block_tree, vb_idx); | |
930 | spin_unlock(&vmap_block_tree_lock); | |
931 | BUG_ON(tmp != vb); | |
932 | ||
933 | free_vmap_area_noflush(vb->va); | |
934 | kfree_rcu(vb, rcu_head); | |
935 | } | |
936 | ||
937 | static void purge_fragmented_blocks(int cpu) | |
938 | { | |
939 | LIST_HEAD(purge); | |
940 | struct vmap_block *vb; | |
941 | struct vmap_block *n_vb; | |
942 | struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); | |
943 | ||
944 | rcu_read_lock(); | |
945 | list_for_each_entry_rcu(vb, &vbq->free, free_list) { | |
946 | ||
947 | if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS)) | |
948 | continue; | |
949 | ||
950 | spin_lock(&vb->lock); | |
951 | if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) { | |
952 | vb->free = 0; /* prevent further allocs after releasing lock */ | |
953 | vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */ | |
954 | vb->dirty_min = 0; | |
955 | vb->dirty_max = VMAP_BBMAP_BITS; | |
956 | spin_lock(&vbq->lock); | |
957 | list_del_rcu(&vb->free_list); | |
958 | spin_unlock(&vbq->lock); | |
959 | spin_unlock(&vb->lock); | |
960 | list_add_tail(&vb->purge, &purge); | |
961 | } else | |
962 | spin_unlock(&vb->lock); | |
963 | } | |
964 | rcu_read_unlock(); | |
965 | ||
966 | list_for_each_entry_safe(vb, n_vb, &purge, purge) { | |
967 | list_del(&vb->purge); | |
968 | free_vmap_block(vb); | |
969 | } | |
970 | } | |
971 | ||
972 | static void purge_fragmented_blocks_allcpus(void) | |
973 | { | |
974 | int cpu; | |
975 | ||
976 | for_each_possible_cpu(cpu) | |
977 | purge_fragmented_blocks(cpu); | |
978 | } | |
979 | ||
980 | static void *vb_alloc(unsigned long size, gfp_t gfp_mask) | |
981 | { | |
982 | struct vmap_block_queue *vbq; | |
983 | struct vmap_block *vb; | |
984 | void *vaddr = NULL; | |
985 | unsigned int order; | |
986 | ||
987 | BUG_ON(offset_in_page(size)); | |
988 | BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); | |
989 | if (WARN_ON(size == 0)) { | |
990 | /* | |
991 | * Allocating 0 bytes isn't what caller wants since | |
992 | * get_order(0) returns funny result. Just warn and terminate | |
993 | * early. | |
994 | */ | |
995 | return NULL; | |
996 | } | |
997 | order = get_order(size); | |
998 | ||
999 | rcu_read_lock(); | |
1000 | vbq = &get_cpu_var(vmap_block_queue); | |
1001 | list_for_each_entry_rcu(vb, &vbq->free, free_list) { | |
1002 | unsigned long pages_off; | |
1003 | ||
1004 | spin_lock(&vb->lock); | |
1005 | if (vb->free < (1UL << order)) { | |
1006 | spin_unlock(&vb->lock); | |
1007 | continue; | |
1008 | } | |
1009 | ||
1010 | pages_off = VMAP_BBMAP_BITS - vb->free; | |
1011 | vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); | |
1012 | vb->free -= 1UL << order; | |
1013 | if (vb->free == 0) { | |
1014 | spin_lock(&vbq->lock); | |
1015 | list_del_rcu(&vb->free_list); | |
1016 | spin_unlock(&vbq->lock); | |
1017 | } | |
1018 | ||
1019 | spin_unlock(&vb->lock); | |
1020 | break; | |
1021 | } | |
1022 | ||
1023 | put_cpu_var(vmap_block_queue); | |
1024 | rcu_read_unlock(); | |
1025 | ||
1026 | /* Allocate new block if nothing was found */ | |
1027 | if (!vaddr) | |
1028 | vaddr = new_vmap_block(order, gfp_mask); | |
1029 | ||
1030 | return vaddr; | |
1031 | } | |
1032 | ||
1033 | static void vb_free(const void *addr, unsigned long size) | |
1034 | { | |
1035 | unsigned long offset; | |
1036 | unsigned long vb_idx; | |
1037 | unsigned int order; | |
1038 | struct vmap_block *vb; | |
1039 | ||
1040 | BUG_ON(offset_in_page(size)); | |
1041 | BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); | |
1042 | ||
1043 | flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size); | |
1044 | ||
1045 | order = get_order(size); | |
1046 | ||
1047 | offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1); | |
1048 | offset >>= PAGE_SHIFT; | |
1049 | ||
1050 | vb_idx = addr_to_vb_idx((unsigned long)addr); | |
1051 | rcu_read_lock(); | |
1052 | vb = radix_tree_lookup(&vmap_block_tree, vb_idx); | |
1053 | rcu_read_unlock(); | |
1054 | BUG_ON(!vb); | |
1055 | ||
1056 | vunmap_page_range((unsigned long)addr, (unsigned long)addr + size); | |
1057 | ||
1058 | spin_lock(&vb->lock); | |
1059 | ||
1060 | /* Expand dirty range */ | |
1061 | vb->dirty_min = min(vb->dirty_min, offset); | |
1062 | vb->dirty_max = max(vb->dirty_max, offset + (1UL << order)); | |
1063 | ||
1064 | vb->dirty += 1UL << order; | |
1065 | if (vb->dirty == VMAP_BBMAP_BITS) { | |
1066 | BUG_ON(vb->free); | |
1067 | spin_unlock(&vb->lock); | |
1068 | free_vmap_block(vb); | |
1069 | } else | |
1070 | spin_unlock(&vb->lock); | |
1071 | } | |
1072 | ||
1073 | /** | |
1074 | * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer | |
1075 | * | |
1076 | * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily | |
1077 | * to amortize TLB flushing overheads. What this means is that any page you | |
1078 | * have now, may, in a former life, have been mapped into kernel virtual | |
1079 | * address by the vmap layer and so there might be some CPUs with TLB entries | |
1080 | * still referencing that page (additional to the regular 1:1 kernel mapping). | |
1081 | * | |
1082 | * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can | |
1083 | * be sure that none of the pages we have control over will have any aliases | |
1084 | * from the vmap layer. | |
1085 | */ | |
1086 | void vm_unmap_aliases(void) | |
1087 | { | |
1088 | unsigned long start = ULONG_MAX, end = 0; | |
1089 | int cpu; | |
1090 | int flush = 0; | |
1091 | ||
1092 | if (unlikely(!vmap_initialized)) | |
1093 | return; | |
1094 | ||
1095 | might_sleep(); | |
1096 | ||
1097 | for_each_possible_cpu(cpu) { | |
1098 | struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); | |
1099 | struct vmap_block *vb; | |
1100 | ||
1101 | rcu_read_lock(); | |
1102 | list_for_each_entry_rcu(vb, &vbq->free, free_list) { | |
1103 | spin_lock(&vb->lock); | |
1104 | if (vb->dirty) { | |
1105 | unsigned long va_start = vb->va->va_start; | |
1106 | unsigned long s, e; | |
1107 | ||
1108 | s = va_start + (vb->dirty_min << PAGE_SHIFT); | |
1109 | e = va_start + (vb->dirty_max << PAGE_SHIFT); | |
1110 | ||
1111 | start = min(s, start); | |
1112 | end = max(e, end); | |
1113 | ||
1114 | flush = 1; | |
1115 | } | |
1116 | spin_unlock(&vb->lock); | |
1117 | } | |
1118 | rcu_read_unlock(); | |
1119 | } | |
1120 | ||
1121 | mutex_lock(&vmap_purge_lock); | |
1122 | purge_fragmented_blocks_allcpus(); | |
1123 | if (!__purge_vmap_area_lazy(start, end) && flush) | |
1124 | flush_tlb_kernel_range(start, end); | |
1125 | mutex_unlock(&vmap_purge_lock); | |
1126 | } | |
1127 | EXPORT_SYMBOL_GPL(vm_unmap_aliases); | |
1128 | ||
1129 | /** | |
1130 | * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram | |
1131 | * @mem: the pointer returned by vm_map_ram | |
1132 | * @count: the count passed to that vm_map_ram call (cannot unmap partial) | |
1133 | */ | |
1134 | void vm_unmap_ram(const void *mem, unsigned int count) | |
1135 | { | |
1136 | unsigned long size = (unsigned long)count << PAGE_SHIFT; | |
1137 | unsigned long addr = (unsigned long)mem; | |
1138 | struct vmap_area *va; | |
1139 | ||
1140 | might_sleep(); | |
1141 | BUG_ON(!addr); | |
1142 | BUG_ON(addr < VMALLOC_START); | |
1143 | BUG_ON(addr > VMALLOC_END); | |
1144 | BUG_ON(!PAGE_ALIGNED(addr)); | |
1145 | ||
1146 | debug_check_no_locks_freed(mem, size); | |
1147 | vmap_debug_free_range(addr, addr+size); | |
1148 | ||
1149 | if (likely(count <= VMAP_MAX_ALLOC)) { | |
1150 | vb_free(mem, size); | |
1151 | return; | |
1152 | } | |
1153 | ||
1154 | va = find_vmap_area(addr); | |
1155 | BUG_ON(!va); | |
1156 | free_unmap_vmap_area(va); | |
1157 | } | |
1158 | EXPORT_SYMBOL(vm_unmap_ram); | |
1159 | ||
1160 | /** | |
1161 | * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space) | |
1162 | * @pages: an array of pointers to the pages to be mapped | |
1163 | * @count: number of pages | |
1164 | * @node: prefer to allocate data structures on this node | |
1165 | * @prot: memory protection to use. PAGE_KERNEL for regular RAM | |
1166 | * | |
1167 | * If you use this function for less than VMAP_MAX_ALLOC pages, it could be | |
1168 | * faster than vmap so it's good. But if you mix long-life and short-life | |
1169 | * objects with vm_map_ram(), it could consume lots of address space through | |
1170 | * fragmentation (especially on a 32bit machine). You could see failures in | |
1171 | * the end. Please use this function for short-lived objects. | |
1172 | * | |
1173 | * Returns: a pointer to the address that has been mapped, or %NULL on failure | |
1174 | */ | |
1175 | void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) | |
1176 | { | |
1177 | unsigned long size = (unsigned long)count << PAGE_SHIFT; | |
1178 | unsigned long addr; | |
1179 | void *mem; | |
1180 | ||
1181 | if (likely(count <= VMAP_MAX_ALLOC)) { | |
1182 | mem = vb_alloc(size, GFP_KERNEL); | |
1183 | if (IS_ERR(mem)) | |
1184 | return NULL; | |
1185 | addr = (unsigned long)mem; | |
1186 | } else { | |
1187 | struct vmap_area *va; | |
1188 | va = alloc_vmap_area(size, PAGE_SIZE, | |
1189 | VMALLOC_START, VMALLOC_END, node, GFP_KERNEL); | |
1190 | if (IS_ERR(va)) | |
1191 | return NULL; | |
1192 | ||
1193 | addr = va->va_start; | |
1194 | mem = (void *)addr; | |
1195 | } | |
1196 | if (vmap_page_range(addr, addr + size, prot, pages) < 0) { | |
1197 | vm_unmap_ram(mem, count); | |
1198 | return NULL; | |
1199 | } | |
1200 | return mem; | |
1201 | } | |
1202 | EXPORT_SYMBOL(vm_map_ram); | |
1203 | ||
1204 | static struct vm_struct *vmlist __initdata; | |
1205 | /** | |
1206 | * vm_area_add_early - add vmap area early during boot | |
1207 | * @vm: vm_struct to add | |
1208 | * | |
1209 | * This function is used to add fixed kernel vm area to vmlist before | |
1210 | * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags | |
1211 | * should contain proper values and the other fields should be zero. | |
1212 | * | |
1213 | * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. | |
1214 | */ | |
1215 | void __init vm_area_add_early(struct vm_struct *vm) | |
1216 | { | |
1217 | struct vm_struct *tmp, **p; | |
1218 | ||
1219 | BUG_ON(vmap_initialized); | |
1220 | for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) { | |
1221 | if (tmp->addr >= vm->addr) { | |
1222 | BUG_ON(tmp->addr < vm->addr + vm->size); | |
1223 | break; | |
1224 | } else | |
1225 | BUG_ON(tmp->addr + tmp->size > vm->addr); | |
1226 | } | |
1227 | vm->next = *p; | |
1228 | *p = vm; | |
1229 | } | |
1230 | ||
1231 | /** | |
1232 | * vm_area_register_early - register vmap area early during boot | |
1233 | * @vm: vm_struct to register | |
1234 | * @align: requested alignment | |
1235 | * | |
1236 | * This function is used to register kernel vm area before | |
1237 | * vmalloc_init() is called. @vm->size and @vm->flags should contain | |
1238 | * proper values on entry and other fields should be zero. On return, | |
1239 | * vm->addr contains the allocated address. | |
1240 | * | |
1241 | * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. | |
1242 | */ | |
1243 | void __init vm_area_register_early(struct vm_struct *vm, size_t align) | |
1244 | { | |
1245 | static size_t vm_init_off __initdata; | |
1246 | unsigned long addr; | |
1247 | ||
1248 | addr = ALIGN(VMALLOC_START + vm_init_off, align); | |
1249 | vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; | |
1250 | ||
1251 | vm->addr = (void *)addr; | |
1252 | ||
1253 | vm_area_add_early(vm); | |
1254 | } | |
1255 | ||
1256 | void __init vmalloc_init(void) | |
1257 | { | |
1258 | struct vmap_area *va; | |
1259 | struct vm_struct *tmp; | |
1260 | int i; | |
1261 | ||
1262 | for_each_possible_cpu(i) { | |
1263 | struct vmap_block_queue *vbq; | |
1264 | struct vfree_deferred *p; | |
1265 | ||
1266 | vbq = &per_cpu(vmap_block_queue, i); | |
1267 | spin_lock_init(&vbq->lock); | |
1268 | INIT_LIST_HEAD(&vbq->free); | |
1269 | p = &per_cpu(vfree_deferred, i); | |
1270 | init_llist_head(&p->list); | |
1271 | INIT_WORK(&p->wq, free_work); | |
1272 | } | |
1273 | ||
1274 | /* Import existing vmlist entries. */ | |
1275 | for (tmp = vmlist; tmp; tmp = tmp->next) { | |
1276 | va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT); | |
1277 | va->flags = VM_VM_AREA; | |
1278 | va->va_start = (unsigned long)tmp->addr; | |
1279 | va->va_end = va->va_start + tmp->size; | |
1280 | va->vm = tmp; | |
1281 | __insert_vmap_area(va); | |
1282 | } | |
1283 | ||
1284 | vmap_area_pcpu_hole = VMALLOC_END; | |
1285 | ||
1286 | vmap_initialized = true; | |
1287 | } | |
1288 | ||
1289 | /** | |
1290 | * map_kernel_range_noflush - map kernel VM area with the specified pages | |
1291 | * @addr: start of the VM area to map | |
1292 | * @size: size of the VM area to map | |
1293 | * @prot: page protection flags to use | |
1294 | * @pages: pages to map | |
1295 | * | |
1296 | * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size | |
1297 | * specify should have been allocated using get_vm_area() and its | |
1298 | * friends. | |
1299 | * | |
1300 | * NOTE: | |
1301 | * This function does NOT do any cache flushing. The caller is | |
1302 | * responsible for calling flush_cache_vmap() on to-be-mapped areas | |
1303 | * before calling this function. | |
1304 | * | |
1305 | * RETURNS: | |
1306 | * The number of pages mapped on success, -errno on failure. | |
1307 | */ | |
1308 | int map_kernel_range_noflush(unsigned long addr, unsigned long size, | |
1309 | pgprot_t prot, struct page **pages) | |
1310 | { | |
1311 | return vmap_page_range_noflush(addr, addr + size, prot, pages); | |
1312 | } | |
1313 | ||
1314 | /** | |
1315 | * unmap_kernel_range_noflush - unmap kernel VM area | |
1316 | * @addr: start of the VM area to unmap | |
1317 | * @size: size of the VM area to unmap | |
1318 | * | |
1319 | * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size | |
1320 | * specify should have been allocated using get_vm_area() and its | |
1321 | * friends. | |
1322 | * | |
1323 | * NOTE: | |
1324 | * This function does NOT do any cache flushing. The caller is | |
1325 | * responsible for calling flush_cache_vunmap() on to-be-mapped areas | |
1326 | * before calling this function and flush_tlb_kernel_range() after. | |
1327 | */ | |
1328 | void unmap_kernel_range_noflush(unsigned long addr, unsigned long size) | |
1329 | { | |
1330 | vunmap_page_range(addr, addr + size); | |
1331 | } | |
1332 | EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush); | |
1333 | ||
1334 | /** | |
1335 | * unmap_kernel_range - unmap kernel VM area and flush cache and TLB | |
1336 | * @addr: start of the VM area to unmap | |
1337 | * @size: size of the VM area to unmap | |
1338 | * | |
1339 | * Similar to unmap_kernel_range_noflush() but flushes vcache before | |
1340 | * the unmapping and tlb after. | |
1341 | */ | |
1342 | void unmap_kernel_range(unsigned long addr, unsigned long size) | |
1343 | { | |
1344 | unsigned long end = addr + size; | |
1345 | ||
1346 | flush_cache_vunmap(addr, end); | |
1347 | vunmap_page_range(addr, end); | |
1348 | flush_tlb_kernel_range(addr, end); | |
1349 | } | |
1350 | EXPORT_SYMBOL_GPL(unmap_kernel_range); | |
1351 | ||
1352 | int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages) | |
1353 | { | |
1354 | unsigned long addr = (unsigned long)area->addr; | |
1355 | unsigned long end = addr + get_vm_area_size(area); | |
1356 | int err; | |
1357 | ||
1358 | err = vmap_page_range(addr, end, prot, pages); | |
1359 | ||
1360 | return err > 0 ? 0 : err; | |
1361 | } | |
1362 | EXPORT_SYMBOL_GPL(map_vm_area); | |
1363 | ||
1364 | static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, | |
1365 | unsigned long flags, const void *caller) | |
1366 | { | |
1367 | spin_lock(&vmap_area_lock); | |
1368 | vm->flags = flags; | |
1369 | vm->addr = (void *)va->va_start; | |
1370 | vm->size = va->va_end - va->va_start; | |
1371 | vm->caller = caller; | |
1372 | va->vm = vm; | |
1373 | va->flags |= VM_VM_AREA; | |
1374 | spin_unlock(&vmap_area_lock); | |
1375 | } | |
1376 | ||
1377 | static void clear_vm_uninitialized_flag(struct vm_struct *vm) | |
1378 | { | |
1379 | /* | |
1380 | * Before removing VM_UNINITIALIZED, | |
1381 | * we should make sure that vm has proper values. | |
1382 | * Pair with smp_rmb() in show_numa_info(). | |
1383 | */ | |
1384 | smp_wmb(); | |
1385 | vm->flags &= ~VM_UNINITIALIZED; | |
1386 | } | |
1387 | ||
1388 | static struct vm_struct *__get_vm_area_node(unsigned long size, | |
1389 | unsigned long align, unsigned long flags, unsigned long start, | |
1390 | unsigned long end, int node, gfp_t gfp_mask, const void *caller) | |
1391 | { | |
1392 | struct vmap_area *va; | |
1393 | struct vm_struct *area; | |
1394 | ||
1395 | BUG_ON(in_interrupt()); | |
1396 | size = PAGE_ALIGN(size); | |
1397 | if (unlikely(!size)) | |
1398 | return NULL; | |
1399 | ||
1400 | if (flags & VM_IOREMAP) | |
1401 | align = 1ul << clamp_t(int, get_count_order_long(size), | |
1402 | PAGE_SHIFT, IOREMAP_MAX_ORDER); | |
1403 | ||
1404 | area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); | |
1405 | if (unlikely(!area)) | |
1406 | return NULL; | |
1407 | ||
1408 | if (!(flags & VM_NO_GUARD)) | |
1409 | size += PAGE_SIZE; | |
1410 | ||
1411 | va = alloc_vmap_area(size, align, start, end, node, gfp_mask); | |
1412 | if (IS_ERR(va)) { | |
1413 | kfree(area); | |
1414 | return NULL; | |
1415 | } | |
1416 | ||
1417 | setup_vmalloc_vm(area, va, flags, caller); | |
1418 | ||
1419 | return area; | |
1420 | } | |
1421 | ||
1422 | struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags, | |
1423 | unsigned long start, unsigned long end) | |
1424 | { | |
1425 | return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE, | |
1426 | GFP_KERNEL, __builtin_return_address(0)); | |
1427 | } | |
1428 | EXPORT_SYMBOL_GPL(__get_vm_area); | |
1429 | ||
1430 | struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, | |
1431 | unsigned long start, unsigned long end, | |
1432 | const void *caller) | |
1433 | { | |
1434 | return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE, | |
1435 | GFP_KERNEL, caller); | |
1436 | } | |
1437 | ||
1438 | /** | |
1439 | * get_vm_area - reserve a contiguous kernel virtual area | |
1440 | * @size: size of the area | |
1441 | * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC | |
1442 | * | |
1443 | * Search an area of @size in the kernel virtual mapping area, | |
1444 | * and reserved it for out purposes. Returns the area descriptor | |
1445 | * on success or %NULL on failure. | |
1446 | */ | |
1447 | struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) | |
1448 | { | |
1449 | return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, | |
1450 | NUMA_NO_NODE, GFP_KERNEL, | |
1451 | __builtin_return_address(0)); | |
1452 | } | |
1453 | ||
1454 | struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, | |
1455 | const void *caller) | |
1456 | { | |
1457 | return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, | |
1458 | NUMA_NO_NODE, GFP_KERNEL, caller); | |
1459 | } | |
1460 | ||
1461 | /** | |
1462 | * find_vm_area - find a continuous kernel virtual area | |
1463 | * @addr: base address | |
1464 | * | |
1465 | * Search for the kernel VM area starting at @addr, and return it. | |
1466 | * It is up to the caller to do all required locking to keep the returned | |
1467 | * pointer valid. | |
1468 | */ | |
1469 | struct vm_struct *find_vm_area(const void *addr) | |
1470 | { | |
1471 | struct vmap_area *va; | |
1472 | ||
1473 | va = find_vmap_area((unsigned long)addr); | |
1474 | if (va && va->flags & VM_VM_AREA) | |
1475 | return va->vm; | |
1476 | ||
1477 | return NULL; | |
1478 | } | |
1479 | ||
1480 | /** | |
1481 | * remove_vm_area - find and remove a continuous kernel virtual area | |
1482 | * @addr: base address | |
1483 | * | |
1484 | * Search for the kernel VM area starting at @addr, and remove it. | |
1485 | * This function returns the found VM area, but using it is NOT safe | |
1486 | * on SMP machines, except for its size or flags. | |
1487 | */ | |
1488 | struct vm_struct *remove_vm_area(const void *addr) | |
1489 | { | |
1490 | struct vmap_area *va; | |
1491 | ||
1492 | might_sleep(); | |
1493 | ||
1494 | va = find_vmap_area((unsigned long)addr); | |
1495 | if (va && va->flags & VM_VM_AREA) { | |
1496 | struct vm_struct *vm = va->vm; | |
1497 | ||
1498 | spin_lock(&vmap_area_lock); | |
1499 | va->vm = NULL; | |
1500 | va->flags &= ~VM_VM_AREA; | |
1501 | va->flags |= VM_LAZY_FREE; | |
1502 | spin_unlock(&vmap_area_lock); | |
1503 | ||
1504 | vmap_debug_free_range(va->va_start, va->va_end); | |
1505 | kasan_free_shadow(vm); | |
1506 | free_unmap_vmap_area(va); | |
1507 | ||
1508 | return vm; | |
1509 | } | |
1510 | return NULL; | |
1511 | } | |
1512 | ||
1513 | static void __vunmap(const void *addr, int deallocate_pages) | |
1514 | { | |
1515 | struct vm_struct *area; | |
1516 | ||
1517 | if (!addr) | |
1518 | return; | |
1519 | ||
1520 | if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n", | |
1521 | addr)) | |
1522 | return; | |
1523 | ||
1524 | area = remove_vm_area(addr); | |
1525 | if (unlikely(!area)) { | |
1526 | WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", | |
1527 | addr); | |
1528 | return; | |
1529 | } | |
1530 | ||
1531 | debug_check_no_locks_freed(addr, get_vm_area_size(area)); | |
1532 | debug_check_no_obj_freed(addr, get_vm_area_size(area)); | |
1533 | ||
1534 | if (deallocate_pages) { | |
1535 | int i; | |
1536 | ||
1537 | for (i = 0; i < area->nr_pages; i++) { | |
1538 | struct page *page = area->pages[i]; | |
1539 | ||
1540 | BUG_ON(!page); | |
1541 | __free_pages(page, 0); | |
1542 | } | |
1543 | ||
1544 | kvfree(area->pages); | |
1545 | } | |
1546 | ||
1547 | kfree(area); | |
1548 | return; | |
1549 | } | |
1550 | ||
1551 | static inline void __vfree_deferred(const void *addr) | |
1552 | { | |
1553 | /* | |
1554 | * Use raw_cpu_ptr() because this can be called from preemptible | |
1555 | * context. Preemption is absolutely fine here, because the llist_add() | |
1556 | * implementation is lockless, so it works even if we are adding to | |
1557 | * nother cpu's list. schedule_work() should be fine with this too. | |
1558 | */ | |
1559 | struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred); | |
1560 | ||
1561 | if (llist_add((struct llist_node *)addr, &p->list)) | |
1562 | schedule_work(&p->wq); | |
1563 | } | |
1564 | ||
1565 | /** | |
1566 | * vfree_atomic - release memory allocated by vmalloc() | |
1567 | * @addr: memory base address | |
1568 | * | |
1569 | * This one is just like vfree() but can be called in any atomic context | |
1570 | * except NMIs. | |
1571 | */ | |
1572 | void vfree_atomic(const void *addr) | |
1573 | { | |
1574 | BUG_ON(in_nmi()); | |
1575 | ||
1576 | kmemleak_free(addr); | |
1577 | ||
1578 | if (!addr) | |
1579 | return; | |
1580 | __vfree_deferred(addr); | |
1581 | } | |
1582 | ||
1583 | /** | |
1584 | * vfree - release memory allocated by vmalloc() | |
1585 | * @addr: memory base address | |
1586 | * | |
1587 | * Free the virtually continuous memory area starting at @addr, as | |
1588 | * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is | |
1589 | * NULL, no operation is performed. | |
1590 | * | |
1591 | * Must not be called in NMI context (strictly speaking, only if we don't | |
1592 | * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling | |
1593 | * conventions for vfree() arch-depenedent would be a really bad idea) | |
1594 | * | |
1595 | * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node) | |
1596 | */ | |
1597 | void vfree(const void *addr) | |
1598 | { | |
1599 | BUG_ON(in_nmi()); | |
1600 | ||
1601 | kmemleak_free(addr); | |
1602 | ||
1603 | if (!addr) | |
1604 | return; | |
1605 | if (unlikely(in_interrupt())) | |
1606 | __vfree_deferred(addr); | |
1607 | else | |
1608 | __vunmap(addr, 1); | |
1609 | } | |
1610 | EXPORT_SYMBOL(vfree); | |
1611 | ||
1612 | /** | |
1613 | * vunmap - release virtual mapping obtained by vmap() | |
1614 | * @addr: memory base address | |
1615 | * | |
1616 | * Free the virtually contiguous memory area starting at @addr, | |
1617 | * which was created from the page array passed to vmap(). | |
1618 | * | |
1619 | * Must not be called in interrupt context. | |
1620 | */ | |
1621 | void vunmap(const void *addr) | |
1622 | { | |
1623 | BUG_ON(in_interrupt()); | |
1624 | might_sleep(); | |
1625 | if (addr) | |
1626 | __vunmap(addr, 0); | |
1627 | } | |
1628 | EXPORT_SYMBOL(vunmap); | |
1629 | ||
1630 | /** | |
1631 | * vmap - map an array of pages into virtually contiguous space | |
1632 | * @pages: array of page pointers | |
1633 | * @count: number of pages to map | |
1634 | * @flags: vm_area->flags | |
1635 | * @prot: page protection for the mapping | |
1636 | * | |
1637 | * Maps @count pages from @pages into contiguous kernel virtual | |
1638 | * space. | |
1639 | */ | |
1640 | void *vmap(struct page **pages, unsigned int count, | |
1641 | unsigned long flags, pgprot_t prot) | |
1642 | { | |
1643 | struct vm_struct *area; | |
1644 | unsigned long size; /* In bytes */ | |
1645 | ||
1646 | might_sleep(); | |
1647 | ||
1648 | if (count > totalram_pages) | |
1649 | return NULL; | |
1650 | ||
1651 | size = (unsigned long)count << PAGE_SHIFT; | |
1652 | area = get_vm_area_caller(size, flags, __builtin_return_address(0)); | |
1653 | if (!area) | |
1654 | return NULL; | |
1655 | ||
1656 | if (map_vm_area(area, prot, pages)) { | |
1657 | vunmap(area->addr); | |
1658 | return NULL; | |
1659 | } | |
1660 | ||
1661 | return area->addr; | |
1662 | } | |
1663 | EXPORT_SYMBOL(vmap); | |
1664 | ||
1665 | static void *__vmalloc_node(unsigned long size, unsigned long align, | |
1666 | gfp_t gfp_mask, pgprot_t prot, | |
1667 | int node, const void *caller); | |
1668 | static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, | |
1669 | pgprot_t prot, int node) | |
1670 | { | |
1671 | struct page **pages; | |
1672 | unsigned int nr_pages, array_size, i; | |
1673 | const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; | |
1674 | const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN; | |
1675 | const gfp_t highmem_mask = (gfp_mask & (GFP_DMA | GFP_DMA32)) ? | |
1676 | 0 : | |
1677 | __GFP_HIGHMEM; | |
1678 | ||
1679 | nr_pages = get_vm_area_size(area) >> PAGE_SHIFT; | |
1680 | array_size = (nr_pages * sizeof(struct page *)); | |
1681 | ||
1682 | area->nr_pages = nr_pages; | |
1683 | /* Please note that the recursion is strictly bounded. */ | |
1684 | if (array_size > PAGE_SIZE) { | |
1685 | pages = __vmalloc_node(array_size, 1, nested_gfp|highmem_mask, | |
1686 | PAGE_KERNEL, node, area->caller); | |
1687 | } else { | |
1688 | pages = kmalloc_node(array_size, nested_gfp, node); | |
1689 | } | |
1690 | area->pages = pages; | |
1691 | if (!area->pages) { | |
1692 | remove_vm_area(area->addr); | |
1693 | kfree(area); | |
1694 | return NULL; | |
1695 | } | |
1696 | ||
1697 | for (i = 0; i < area->nr_pages; i++) { | |
1698 | struct page *page; | |
1699 | ||
1700 | if (fatal_signal_pending(current)) { | |
1701 | area->nr_pages = i; | |
1702 | goto fail_no_warn; | |
1703 | } | |
1704 | ||
1705 | if (node == NUMA_NO_NODE) | |
1706 | page = alloc_page(alloc_mask|highmem_mask); | |
1707 | else | |
1708 | page = alloc_pages_node(node, alloc_mask|highmem_mask, 0); | |
1709 | ||
1710 | if (unlikely(!page)) { | |
1711 | /* Successfully allocated i pages, free them in __vunmap() */ | |
1712 | area->nr_pages = i; | |
1713 | goto fail; | |
1714 | } | |
1715 | area->pages[i] = page; | |
1716 | if (gfpflags_allow_blocking(gfp_mask|highmem_mask)) | |
1717 | cond_resched(); | |
1718 | } | |
1719 | ||
1720 | if (map_vm_area(area, prot, pages)) | |
1721 | goto fail; | |
1722 | return area->addr; | |
1723 | ||
1724 | fail: | |
1725 | warn_alloc(gfp_mask, NULL, | |
1726 | "vmalloc: allocation failure, allocated %ld of %ld bytes", | |
1727 | (area->nr_pages*PAGE_SIZE), area->size); | |
1728 | fail_no_warn: | |
1729 | vfree(area->addr); | |
1730 | return NULL; | |
1731 | } | |
1732 | ||
1733 | /** | |
1734 | * __vmalloc_node_range - allocate virtually contiguous memory | |
1735 | * @size: allocation size | |
1736 | * @align: desired alignment | |
1737 | * @start: vm area range start | |
1738 | * @end: vm area range end | |
1739 | * @gfp_mask: flags for the page level allocator | |
1740 | * @prot: protection mask for the allocated pages | |
1741 | * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) | |
1742 | * @node: node to use for allocation or NUMA_NO_NODE | |
1743 | * @caller: caller's return address | |
1744 | * | |
1745 | * Allocate enough pages to cover @size from the page level | |
1746 | * allocator with @gfp_mask flags. Map them into contiguous | |
1747 | * kernel virtual space, using a pagetable protection of @prot. | |
1748 | */ | |
1749 | void *__vmalloc_node_range(unsigned long size, unsigned long align, | |
1750 | unsigned long start, unsigned long end, gfp_t gfp_mask, | |
1751 | pgprot_t prot, unsigned long vm_flags, int node, | |
1752 | const void *caller) | |
1753 | { | |
1754 | struct vm_struct *area; | |
1755 | void *addr; | |
1756 | unsigned long real_size = size; | |
1757 | ||
1758 | size = PAGE_ALIGN(size); | |
1759 | if (!size || (size >> PAGE_SHIFT) > totalram_pages) | |
1760 | goto fail; | |
1761 | ||
1762 | area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED | | |
1763 | vm_flags, start, end, node, gfp_mask, caller); | |
1764 | if (!area) | |
1765 | goto fail; | |
1766 | ||
1767 | addr = __vmalloc_area_node(area, gfp_mask, prot, node); | |
1768 | if (!addr) | |
1769 | return NULL; | |
1770 | ||
1771 | /* | |
1772 | * In this function, newly allocated vm_struct has VM_UNINITIALIZED | |
1773 | * flag. It means that vm_struct is not fully initialized. | |
1774 | * Now, it is fully initialized, so remove this flag here. | |
1775 | */ | |
1776 | clear_vm_uninitialized_flag(area); | |
1777 | ||
1778 | kmemleak_vmalloc(area, size, gfp_mask); | |
1779 | ||
1780 | return addr; | |
1781 | ||
1782 | fail: | |
1783 | warn_alloc(gfp_mask, NULL, | |
1784 | "vmalloc: allocation failure: %lu bytes", real_size); | |
1785 | return NULL; | |
1786 | } | |
1787 | ||
1788 | /** | |
1789 | * __vmalloc_node - allocate virtually contiguous memory | |
1790 | * @size: allocation size | |
1791 | * @align: desired alignment | |
1792 | * @gfp_mask: flags for the page level allocator | |
1793 | * @prot: protection mask for the allocated pages | |
1794 | * @node: node to use for allocation or NUMA_NO_NODE | |
1795 | * @caller: caller's return address | |
1796 | * | |
1797 | * Allocate enough pages to cover @size from the page level | |
1798 | * allocator with @gfp_mask flags. Map them into contiguous | |
1799 | * kernel virtual space, using a pagetable protection of @prot. | |
1800 | * | |
1801 | * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL | |
1802 | * and __GFP_NOFAIL are not supported | |
1803 | * | |
1804 | * Any use of gfp flags outside of GFP_KERNEL should be consulted | |
1805 | * with mm people. | |
1806 | * | |
1807 | */ | |
1808 | static void *__vmalloc_node(unsigned long size, unsigned long align, | |
1809 | gfp_t gfp_mask, pgprot_t prot, | |
1810 | int node, const void *caller) | |
1811 | { | |
1812 | return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, | |
1813 | gfp_mask, prot, 0, node, caller); | |
1814 | } | |
1815 | ||
1816 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) | |
1817 | { | |
1818 | return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE, | |
1819 | __builtin_return_address(0)); | |
1820 | } | |
1821 | EXPORT_SYMBOL(__vmalloc); | |
1822 | ||
1823 | static inline void *__vmalloc_node_flags(unsigned long size, | |
1824 | int node, gfp_t flags) | |
1825 | { | |
1826 | return __vmalloc_node(size, 1, flags, PAGE_KERNEL, | |
1827 | node, __builtin_return_address(0)); | |
1828 | } | |
1829 | ||
1830 | ||
1831 | void *__vmalloc_node_flags_caller(unsigned long size, int node, gfp_t flags, | |
1832 | void *caller) | |
1833 | { | |
1834 | return __vmalloc_node(size, 1, flags, PAGE_KERNEL, node, caller); | |
1835 | } | |
1836 | ||
1837 | /** | |
1838 | * vmalloc - allocate virtually contiguous memory | |
1839 | * @size: allocation size | |
1840 | * Allocate enough pages to cover @size from the page level | |
1841 | * allocator and map them into contiguous kernel virtual space. | |
1842 | * | |
1843 | * For tight control over page level allocator and protection flags | |
1844 | * use __vmalloc() instead. | |
1845 | */ | |
1846 | void *vmalloc(unsigned long size) | |
1847 | { | |
1848 | return __vmalloc_node_flags(size, NUMA_NO_NODE, | |
1849 | GFP_KERNEL); | |
1850 | } | |
1851 | EXPORT_SYMBOL(vmalloc); | |
1852 | ||
1853 | /** | |
1854 | * vzalloc - allocate virtually contiguous memory with zero fill | |
1855 | * @size: allocation size | |
1856 | * Allocate enough pages to cover @size from the page level | |
1857 | * allocator and map them into contiguous kernel virtual space. | |
1858 | * The memory allocated is set to zero. | |
1859 | * | |
1860 | * For tight control over page level allocator and protection flags | |
1861 | * use __vmalloc() instead. | |
1862 | */ | |
1863 | void *vzalloc(unsigned long size) | |
1864 | { | |
1865 | return __vmalloc_node_flags(size, NUMA_NO_NODE, | |
1866 | GFP_KERNEL | __GFP_ZERO); | |
1867 | } | |
1868 | EXPORT_SYMBOL(vzalloc); | |
1869 | ||
1870 | /** | |
1871 | * vmalloc_user - allocate zeroed virtually contiguous memory for userspace | |
1872 | * @size: allocation size | |
1873 | * | |
1874 | * The resulting memory area is zeroed so it can be mapped to userspace | |
1875 | * without leaking data. | |
1876 | */ | |
1877 | void *vmalloc_user(unsigned long size) | |
1878 | { | |
1879 | struct vm_struct *area; | |
1880 | void *ret; | |
1881 | ||
1882 | ret = __vmalloc_node(size, SHMLBA, | |
1883 | GFP_KERNEL | __GFP_ZERO, | |
1884 | PAGE_KERNEL, NUMA_NO_NODE, | |
1885 | __builtin_return_address(0)); | |
1886 | if (ret) { | |
1887 | area = find_vm_area(ret); | |
1888 | area->flags |= VM_USERMAP; | |
1889 | } | |
1890 | return ret; | |
1891 | } | |
1892 | EXPORT_SYMBOL(vmalloc_user); | |
1893 | ||
1894 | /** | |
1895 | * vmalloc_node - allocate memory on a specific node | |
1896 | * @size: allocation size | |
1897 | * @node: numa node | |
1898 | * | |
1899 | * Allocate enough pages to cover @size from the page level | |
1900 | * allocator and map them into contiguous kernel virtual space. | |
1901 | * | |
1902 | * For tight control over page level allocator and protection flags | |
1903 | * use __vmalloc() instead. | |
1904 | */ | |
1905 | void *vmalloc_node(unsigned long size, int node) | |
1906 | { | |
1907 | return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL, | |
1908 | node, __builtin_return_address(0)); | |
1909 | } | |
1910 | EXPORT_SYMBOL(vmalloc_node); | |
1911 | ||
1912 | /** | |
1913 | * vzalloc_node - allocate memory on a specific node with zero fill | |
1914 | * @size: allocation size | |
1915 | * @node: numa node | |
1916 | * | |
1917 | * Allocate enough pages to cover @size from the page level | |
1918 | * allocator and map them into contiguous kernel virtual space. | |
1919 | * The memory allocated is set to zero. | |
1920 | * | |
1921 | * For tight control over page level allocator and protection flags | |
1922 | * use __vmalloc_node() instead. | |
1923 | */ | |
1924 | void *vzalloc_node(unsigned long size, int node) | |
1925 | { | |
1926 | return __vmalloc_node_flags(size, node, | |
1927 | GFP_KERNEL | __GFP_ZERO); | |
1928 | } | |
1929 | EXPORT_SYMBOL(vzalloc_node); | |
1930 | ||
1931 | #ifndef PAGE_KERNEL_EXEC | |
1932 | # define PAGE_KERNEL_EXEC PAGE_KERNEL | |
1933 | #endif | |
1934 | ||
1935 | /** | |
1936 | * vmalloc_exec - allocate virtually contiguous, executable memory | |
1937 | * @size: allocation size | |
1938 | * | |
1939 | * Kernel-internal function to allocate enough pages to cover @size | |
1940 | * the page level allocator and map them into contiguous and | |
1941 | * executable kernel virtual space. | |
1942 | * | |
1943 | * For tight control over page level allocator and protection flags | |
1944 | * use __vmalloc() instead. | |
1945 | */ | |
1946 | ||
1947 | void *vmalloc_exec(unsigned long size) | |
1948 | { | |
1949 | return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC, | |
1950 | NUMA_NO_NODE, __builtin_return_address(0)); | |
1951 | } | |
1952 | ||
1953 | #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) | |
1954 | #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL | |
1955 | #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA) | |
1956 | #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL | |
1957 | #else | |
1958 | #define GFP_VMALLOC32 GFP_KERNEL | |
1959 | #endif | |
1960 | ||
1961 | /** | |
1962 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
1963 | * @size: allocation size | |
1964 | * | |
1965 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
1966 | * page level allocator and map them into contiguous kernel virtual space. | |
1967 | */ | |
1968 | void *vmalloc_32(unsigned long size) | |
1969 | { | |
1970 | return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL, | |
1971 | NUMA_NO_NODE, __builtin_return_address(0)); | |
1972 | } | |
1973 | EXPORT_SYMBOL(vmalloc_32); | |
1974 | ||
1975 | /** | |
1976 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
1977 | * @size: allocation size | |
1978 | * | |
1979 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
1980 | * mapped to userspace without leaking data. | |
1981 | */ | |
1982 | void *vmalloc_32_user(unsigned long size) | |
1983 | { | |
1984 | struct vm_struct *area; | |
1985 | void *ret; | |
1986 | ||
1987 | ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, | |
1988 | NUMA_NO_NODE, __builtin_return_address(0)); | |
1989 | if (ret) { | |
1990 | area = find_vm_area(ret); | |
1991 | area->flags |= VM_USERMAP; | |
1992 | } | |
1993 | return ret; | |
1994 | } | |
1995 | EXPORT_SYMBOL(vmalloc_32_user); | |
1996 | ||
1997 | /* | |
1998 | * small helper routine , copy contents to buf from addr. | |
1999 | * If the page is not present, fill zero. | |
2000 | */ | |
2001 | ||
2002 | static int aligned_vread(char *buf, char *addr, unsigned long count) | |
2003 | { | |
2004 | struct page *p; | |
2005 | int copied = 0; | |
2006 | ||
2007 | while (count) { | |
2008 | unsigned long offset, length; | |
2009 | ||
2010 | offset = offset_in_page(addr); | |
2011 | length = PAGE_SIZE - offset; | |
2012 | if (length > count) | |
2013 | length = count; | |
2014 | p = vmalloc_to_page(addr); | |
2015 | /* | |
2016 | * To do safe access to this _mapped_ area, we need | |
2017 | * lock. But adding lock here means that we need to add | |
2018 | * overhead of vmalloc()/vfree() calles for this _debug_ | |
2019 | * interface, rarely used. Instead of that, we'll use | |
2020 | * kmap() and get small overhead in this access function. | |
2021 | */ | |
2022 | if (p) { | |
2023 | /* | |
2024 | * we can expect USER0 is not used (see vread/vwrite's | |
2025 | * function description) | |
2026 | */ | |
2027 | void *map = kmap_atomic(p); | |
2028 | memcpy(buf, map + offset, length); | |
2029 | kunmap_atomic(map); | |
2030 | } else | |
2031 | memset(buf, 0, length); | |
2032 | ||
2033 | addr += length; | |
2034 | buf += length; | |
2035 | copied += length; | |
2036 | count -= length; | |
2037 | } | |
2038 | return copied; | |
2039 | } | |
2040 | ||
2041 | static int aligned_vwrite(char *buf, char *addr, unsigned long count) | |
2042 | { | |
2043 | struct page *p; | |
2044 | int copied = 0; | |
2045 | ||
2046 | while (count) { | |
2047 | unsigned long offset, length; | |
2048 | ||
2049 | offset = offset_in_page(addr); | |
2050 | length = PAGE_SIZE - offset; | |
2051 | if (length > count) | |
2052 | length = count; | |
2053 | p = vmalloc_to_page(addr); | |
2054 | /* | |
2055 | * To do safe access to this _mapped_ area, we need | |
2056 | * lock. But adding lock here means that we need to add | |
2057 | * overhead of vmalloc()/vfree() calles for this _debug_ | |
2058 | * interface, rarely used. Instead of that, we'll use | |
2059 | * kmap() and get small overhead in this access function. | |
2060 | */ | |
2061 | if (p) { | |
2062 | /* | |
2063 | * we can expect USER0 is not used (see vread/vwrite's | |
2064 | * function description) | |
2065 | */ | |
2066 | void *map = kmap_atomic(p); | |
2067 | memcpy(map + offset, buf, length); | |
2068 | kunmap_atomic(map); | |
2069 | } | |
2070 | addr += length; | |
2071 | buf += length; | |
2072 | copied += length; | |
2073 | count -= length; | |
2074 | } | |
2075 | return copied; | |
2076 | } | |
2077 | ||
2078 | /** | |
2079 | * vread() - read vmalloc area in a safe way. | |
2080 | * @buf: buffer for reading data | |
2081 | * @addr: vm address. | |
2082 | * @count: number of bytes to be read. | |
2083 | * | |
2084 | * Returns # of bytes which addr and buf should be increased. | |
2085 | * (same number to @count). Returns 0 if [addr...addr+count) doesn't | |
2086 | * includes any intersect with alive vmalloc area. | |
2087 | * | |
2088 | * This function checks that addr is a valid vmalloc'ed area, and | |
2089 | * copy data from that area to a given buffer. If the given memory range | |
2090 | * of [addr...addr+count) includes some valid address, data is copied to | |
2091 | * proper area of @buf. If there are memory holes, they'll be zero-filled. | |
2092 | * IOREMAP area is treated as memory hole and no copy is done. | |
2093 | * | |
2094 | * If [addr...addr+count) doesn't includes any intersects with alive | |
2095 | * vm_struct area, returns 0. @buf should be kernel's buffer. | |
2096 | * | |
2097 | * Note: In usual ops, vread() is never necessary because the caller | |
2098 | * should know vmalloc() area is valid and can use memcpy(). | |
2099 | * This is for routines which have to access vmalloc area without | |
2100 | * any informaion, as /dev/kmem. | |
2101 | * | |
2102 | */ | |
2103 | ||
2104 | long vread(char *buf, char *addr, unsigned long count) | |
2105 | { | |
2106 | struct vmap_area *va; | |
2107 | struct vm_struct *vm; | |
2108 | char *vaddr, *buf_start = buf; | |
2109 | unsigned long buflen = count; | |
2110 | unsigned long n; | |
2111 | ||
2112 | /* Don't allow overflow */ | |
2113 | if ((unsigned long) addr + count < count) | |
2114 | count = -(unsigned long) addr; | |
2115 | ||
2116 | spin_lock(&vmap_area_lock); | |
2117 | list_for_each_entry(va, &vmap_area_list, list) { | |
2118 | if (!count) | |
2119 | break; | |
2120 | ||
2121 | if (!(va->flags & VM_VM_AREA)) | |
2122 | continue; | |
2123 | ||
2124 | vm = va->vm; | |
2125 | vaddr = (char *) vm->addr; | |
2126 | if (addr >= vaddr + get_vm_area_size(vm)) | |
2127 | continue; | |
2128 | while (addr < vaddr) { | |
2129 | if (count == 0) | |
2130 | goto finished; | |
2131 | *buf = '\0'; | |
2132 | buf++; | |
2133 | addr++; | |
2134 | count--; | |
2135 | } | |
2136 | n = vaddr + get_vm_area_size(vm) - addr; | |
2137 | if (n > count) | |
2138 | n = count; | |
2139 | if (!(vm->flags & VM_IOREMAP)) | |
2140 | aligned_vread(buf, addr, n); | |
2141 | else /* IOREMAP area is treated as memory hole */ | |
2142 | memset(buf, 0, n); | |
2143 | buf += n; | |
2144 | addr += n; | |
2145 | count -= n; | |
2146 | } | |
2147 | finished: | |
2148 | spin_unlock(&vmap_area_lock); | |
2149 | ||
2150 | if (buf == buf_start) | |
2151 | return 0; | |
2152 | /* zero-fill memory holes */ | |
2153 | if (buf != buf_start + buflen) | |
2154 | memset(buf, 0, buflen - (buf - buf_start)); | |
2155 | ||
2156 | return buflen; | |
2157 | } | |
2158 | ||
2159 | /** | |
2160 | * vwrite() - write vmalloc area in a safe way. | |
2161 | * @buf: buffer for source data | |
2162 | * @addr: vm address. | |
2163 | * @count: number of bytes to be read. | |
2164 | * | |
2165 | * Returns # of bytes which addr and buf should be incresed. | |
2166 | * (same number to @count). | |
2167 | * If [addr...addr+count) doesn't includes any intersect with valid | |
2168 | * vmalloc area, returns 0. | |
2169 | * | |
2170 | * This function checks that addr is a valid vmalloc'ed area, and | |
2171 | * copy data from a buffer to the given addr. If specified range of | |
2172 | * [addr...addr+count) includes some valid address, data is copied from | |
2173 | * proper area of @buf. If there are memory holes, no copy to hole. | |
2174 | * IOREMAP area is treated as memory hole and no copy is done. | |
2175 | * | |
2176 | * If [addr...addr+count) doesn't includes any intersects with alive | |
2177 | * vm_struct area, returns 0. @buf should be kernel's buffer. | |
2178 | * | |
2179 | * Note: In usual ops, vwrite() is never necessary because the caller | |
2180 | * should know vmalloc() area is valid and can use memcpy(). | |
2181 | * This is for routines which have to access vmalloc area without | |
2182 | * any informaion, as /dev/kmem. | |
2183 | */ | |
2184 | ||
2185 | long vwrite(char *buf, char *addr, unsigned long count) | |
2186 | { | |
2187 | struct vmap_area *va; | |
2188 | struct vm_struct *vm; | |
2189 | char *vaddr; | |
2190 | unsigned long n, buflen; | |
2191 | int copied = 0; | |
2192 | ||
2193 | /* Don't allow overflow */ | |
2194 | if ((unsigned long) addr + count < count) | |
2195 | count = -(unsigned long) addr; | |
2196 | buflen = count; | |
2197 | ||
2198 | spin_lock(&vmap_area_lock); | |
2199 | list_for_each_entry(va, &vmap_area_list, list) { | |
2200 | if (!count) | |
2201 | break; | |
2202 | ||
2203 | if (!(va->flags & VM_VM_AREA)) | |
2204 | continue; | |
2205 | ||
2206 | vm = va->vm; | |
2207 | vaddr = (char *) vm->addr; | |
2208 | if (addr >= vaddr + get_vm_area_size(vm)) | |
2209 | continue; | |
2210 | while (addr < vaddr) { | |
2211 | if (count == 0) | |
2212 | goto finished; | |
2213 | buf++; | |
2214 | addr++; | |
2215 | count--; | |
2216 | } | |
2217 | n = vaddr + get_vm_area_size(vm) - addr; | |
2218 | if (n > count) | |
2219 | n = count; | |
2220 | if (!(vm->flags & VM_IOREMAP)) { | |
2221 | aligned_vwrite(buf, addr, n); | |
2222 | copied++; | |
2223 | } | |
2224 | buf += n; | |
2225 | addr += n; | |
2226 | count -= n; | |
2227 | } | |
2228 | finished: | |
2229 | spin_unlock(&vmap_area_lock); | |
2230 | if (!copied) | |
2231 | return 0; | |
2232 | return buflen; | |
2233 | } | |
2234 | ||
2235 | /** | |
2236 | * remap_vmalloc_range_partial - map vmalloc pages to userspace | |
2237 | * @vma: vma to cover | |
2238 | * @uaddr: target user address to start at | |
2239 | * @kaddr: virtual address of vmalloc kernel memory | |
2240 | * @size: size of map area | |
2241 | * | |
2242 | * Returns: 0 for success, -Exxx on failure | |
2243 | * | |
2244 | * This function checks that @kaddr is a valid vmalloc'ed area, | |
2245 | * and that it is big enough to cover the range starting at | |
2246 | * @uaddr in @vma. Will return failure if that criteria isn't | |
2247 | * met. | |
2248 | * | |
2249 | * Similar to remap_pfn_range() (see mm/memory.c) | |
2250 | */ | |
2251 | int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, | |
2252 | void *kaddr, unsigned long size) | |
2253 | { | |
2254 | struct vm_struct *area; | |
2255 | ||
2256 | size = PAGE_ALIGN(size); | |
2257 | ||
2258 | if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr)) | |
2259 | return -EINVAL; | |
2260 | ||
2261 | area = find_vm_area(kaddr); | |
2262 | if (!area) | |
2263 | return -EINVAL; | |
2264 | ||
2265 | if (!(area->flags & VM_USERMAP)) | |
2266 | return -EINVAL; | |
2267 | ||
2268 | if (kaddr + size > area->addr + area->size) | |
2269 | return -EINVAL; | |
2270 | ||
2271 | do { | |
2272 | struct page *page = vmalloc_to_page(kaddr); | |
2273 | int ret; | |
2274 | ||
2275 | ret = vm_insert_page(vma, uaddr, page); | |
2276 | if (ret) | |
2277 | return ret; | |
2278 | ||
2279 | uaddr += PAGE_SIZE; | |
2280 | kaddr += PAGE_SIZE; | |
2281 | size -= PAGE_SIZE; | |
2282 | } while (size > 0); | |
2283 | ||
2284 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; | |
2285 | ||
2286 | return 0; | |
2287 | } | |
2288 | EXPORT_SYMBOL(remap_vmalloc_range_partial); | |
2289 | ||
2290 | /** | |
2291 | * remap_vmalloc_range - map vmalloc pages to userspace | |
2292 | * @vma: vma to cover (map full range of vma) | |
2293 | * @addr: vmalloc memory | |
2294 | * @pgoff: number of pages into addr before first page to map | |
2295 | * | |
2296 | * Returns: 0 for success, -Exxx on failure | |
2297 | * | |
2298 | * This function checks that addr is a valid vmalloc'ed area, and | |
2299 | * that it is big enough to cover the vma. Will return failure if | |
2300 | * that criteria isn't met. | |
2301 | * | |
2302 | * Similar to remap_pfn_range() (see mm/memory.c) | |
2303 | */ | |
2304 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, | |
2305 | unsigned long pgoff) | |
2306 | { | |
2307 | return remap_vmalloc_range_partial(vma, vma->vm_start, | |
2308 | addr + (pgoff << PAGE_SHIFT), | |
2309 | vma->vm_end - vma->vm_start); | |
2310 | } | |
2311 | EXPORT_SYMBOL(remap_vmalloc_range); | |
2312 | ||
2313 | /* | |
2314 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to | |
2315 | * have one. | |
2316 | */ | |
2317 | void __weak vmalloc_sync_all(void) | |
2318 | { | |
2319 | } | |
2320 | ||
2321 | ||
2322 | static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data) | |
2323 | { | |
2324 | pte_t ***p = data; | |
2325 | ||
2326 | if (p) { | |
2327 | *(*p) = pte; | |
2328 | (*p)++; | |
2329 | } | |
2330 | return 0; | |
2331 | } | |
2332 | ||
2333 | /** | |
2334 | * alloc_vm_area - allocate a range of kernel address space | |
2335 | * @size: size of the area | |
2336 | * @ptes: returns the PTEs for the address space | |
2337 | * | |
2338 | * Returns: NULL on failure, vm_struct on success | |
2339 | * | |
2340 | * This function reserves a range of kernel address space, and | |
2341 | * allocates pagetables to map that range. No actual mappings | |
2342 | * are created. | |
2343 | * | |
2344 | * If @ptes is non-NULL, pointers to the PTEs (in init_mm) | |
2345 | * allocated for the VM area are returned. | |
2346 | */ | |
2347 | struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) | |
2348 | { | |
2349 | struct vm_struct *area; | |
2350 | ||
2351 | area = get_vm_area_caller(size, VM_IOREMAP, | |
2352 | __builtin_return_address(0)); | |
2353 | if (area == NULL) | |
2354 | return NULL; | |
2355 | ||
2356 | /* | |
2357 | * This ensures that page tables are constructed for this region | |
2358 | * of kernel virtual address space and mapped into init_mm. | |
2359 | */ | |
2360 | if (apply_to_page_range(&init_mm, (unsigned long)area->addr, | |
2361 | size, f, ptes ? &ptes : NULL)) { | |
2362 | free_vm_area(area); | |
2363 | return NULL; | |
2364 | } | |
2365 | ||
2366 | return area; | |
2367 | } | |
2368 | EXPORT_SYMBOL_GPL(alloc_vm_area); | |
2369 | ||
2370 | void free_vm_area(struct vm_struct *area) | |
2371 | { | |
2372 | struct vm_struct *ret; | |
2373 | ret = remove_vm_area(area->addr); | |
2374 | BUG_ON(ret != area); | |
2375 | kfree(area); | |
2376 | } | |
2377 | EXPORT_SYMBOL_GPL(free_vm_area); | |
2378 | ||
2379 | #ifdef CONFIG_SMP | |
2380 | static struct vmap_area *node_to_va(struct rb_node *n) | |
2381 | { | |
2382 | return rb_entry_safe(n, struct vmap_area, rb_node); | |
2383 | } | |
2384 | ||
2385 | /** | |
2386 | * pvm_find_next_prev - find the next and prev vmap_area surrounding @end | |
2387 | * @end: target address | |
2388 | * @pnext: out arg for the next vmap_area | |
2389 | * @pprev: out arg for the previous vmap_area | |
2390 | * | |
2391 | * Returns: %true if either or both of next and prev are found, | |
2392 | * %false if no vmap_area exists | |
2393 | * | |
2394 | * Find vmap_areas end addresses of which enclose @end. ie. if not | |
2395 | * NULL, *pnext->va_end > @end and *pprev->va_end <= @end. | |
2396 | */ | |
2397 | static bool pvm_find_next_prev(unsigned long end, | |
2398 | struct vmap_area **pnext, | |
2399 | struct vmap_area **pprev) | |
2400 | { | |
2401 | struct rb_node *n = vmap_area_root.rb_node; | |
2402 | struct vmap_area *va = NULL; | |
2403 | ||
2404 | while (n) { | |
2405 | va = rb_entry(n, struct vmap_area, rb_node); | |
2406 | if (end < va->va_end) | |
2407 | n = n->rb_left; | |
2408 | else if (end > va->va_end) | |
2409 | n = n->rb_right; | |
2410 | else | |
2411 | break; | |
2412 | } | |
2413 | ||
2414 | if (!va) | |
2415 | return false; | |
2416 | ||
2417 | if (va->va_end > end) { | |
2418 | *pnext = va; | |
2419 | *pprev = node_to_va(rb_prev(&(*pnext)->rb_node)); | |
2420 | } else { | |
2421 | *pprev = va; | |
2422 | *pnext = node_to_va(rb_next(&(*pprev)->rb_node)); | |
2423 | } | |
2424 | return true; | |
2425 | } | |
2426 | ||
2427 | /** | |
2428 | * pvm_determine_end - find the highest aligned address between two vmap_areas | |
2429 | * @pnext: in/out arg for the next vmap_area | |
2430 | * @pprev: in/out arg for the previous vmap_area | |
2431 | * @align: alignment | |
2432 | * | |
2433 | * Returns: determined end address | |
2434 | * | |
2435 | * Find the highest aligned address between *@pnext and *@pprev below | |
2436 | * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned | |
2437 | * down address is between the end addresses of the two vmap_areas. | |
2438 | * | |
2439 | * Please note that the address returned by this function may fall | |
2440 | * inside *@pnext vmap_area. The caller is responsible for checking | |
2441 | * that. | |
2442 | */ | |
2443 | static unsigned long pvm_determine_end(struct vmap_area **pnext, | |
2444 | struct vmap_area **pprev, | |
2445 | unsigned long align) | |
2446 | { | |
2447 | const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); | |
2448 | unsigned long addr; | |
2449 | ||
2450 | if (*pnext) | |
2451 | addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end); | |
2452 | else | |
2453 | addr = vmalloc_end; | |
2454 | ||
2455 | while (*pprev && (*pprev)->va_end > addr) { | |
2456 | *pnext = *pprev; | |
2457 | *pprev = node_to_va(rb_prev(&(*pnext)->rb_node)); | |
2458 | } | |
2459 | ||
2460 | return addr; | |
2461 | } | |
2462 | ||
2463 | /** | |
2464 | * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator | |
2465 | * @offsets: array containing offset of each area | |
2466 | * @sizes: array containing size of each area | |
2467 | * @nr_vms: the number of areas to allocate | |
2468 | * @align: alignment, all entries in @offsets and @sizes must be aligned to this | |
2469 | * | |
2470 | * Returns: kmalloc'd vm_struct pointer array pointing to allocated | |
2471 | * vm_structs on success, %NULL on failure | |
2472 | * | |
2473 | * Percpu allocator wants to use congruent vm areas so that it can | |
2474 | * maintain the offsets among percpu areas. This function allocates | |
2475 | * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to | |
2476 | * be scattered pretty far, distance between two areas easily going up | |
2477 | * to gigabytes. To avoid interacting with regular vmallocs, these | |
2478 | * areas are allocated from top. | |
2479 | * | |
2480 | * Despite its complicated look, this allocator is rather simple. It | |
2481 | * does everything top-down and scans areas from the end looking for | |
2482 | * matching slot. While scanning, if any of the areas overlaps with | |
2483 | * existing vmap_area, the base address is pulled down to fit the | |
2484 | * area. Scanning is repeated till all the areas fit and then all | |
2485 | * necessary data structres are inserted and the result is returned. | |
2486 | */ | |
2487 | struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, | |
2488 | const size_t *sizes, int nr_vms, | |
2489 | size_t align) | |
2490 | { | |
2491 | const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); | |
2492 | const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); | |
2493 | struct vmap_area **vas, *prev, *next; | |
2494 | struct vm_struct **vms; | |
2495 | int area, area2, last_area, term_area; | |
2496 | unsigned long base, start, end, last_end; | |
2497 | bool purged = false; | |
2498 | ||
2499 | /* verify parameters and allocate data structures */ | |
2500 | BUG_ON(offset_in_page(align) || !is_power_of_2(align)); | |
2501 | for (last_area = 0, area = 0; area < nr_vms; area++) { | |
2502 | start = offsets[area]; | |
2503 | end = start + sizes[area]; | |
2504 | ||
2505 | /* is everything aligned properly? */ | |
2506 | BUG_ON(!IS_ALIGNED(offsets[area], align)); | |
2507 | BUG_ON(!IS_ALIGNED(sizes[area], align)); | |
2508 | ||
2509 | /* detect the area with the highest address */ | |
2510 | if (start > offsets[last_area]) | |
2511 | last_area = area; | |
2512 | ||
2513 | for (area2 = 0; area2 < nr_vms; area2++) { | |
2514 | unsigned long start2 = offsets[area2]; | |
2515 | unsigned long end2 = start2 + sizes[area2]; | |
2516 | ||
2517 | if (area2 == area) | |
2518 | continue; | |
2519 | ||
2520 | BUG_ON(start2 >= start && start2 < end); | |
2521 | BUG_ON(end2 <= end && end2 > start); | |
2522 | } | |
2523 | } | |
2524 | last_end = offsets[last_area] + sizes[last_area]; | |
2525 | ||
2526 | if (vmalloc_end - vmalloc_start < last_end) { | |
2527 | WARN_ON(true); | |
2528 | return NULL; | |
2529 | } | |
2530 | ||
2531 | vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL); | |
2532 | vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL); | |
2533 | if (!vas || !vms) | |
2534 | goto err_free2; | |
2535 | ||
2536 | for (area = 0; area < nr_vms; area++) { | |
2537 | vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL); | |
2538 | vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL); | |
2539 | if (!vas[area] || !vms[area]) | |
2540 | goto err_free; | |
2541 | } | |
2542 | retry: | |
2543 | spin_lock(&vmap_area_lock); | |
2544 | ||
2545 | /* start scanning - we scan from the top, begin with the last area */ | |
2546 | area = term_area = last_area; | |
2547 | start = offsets[area]; | |
2548 | end = start + sizes[area]; | |
2549 | ||
2550 | if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) { | |
2551 | base = vmalloc_end - last_end; | |
2552 | goto found; | |
2553 | } | |
2554 | base = pvm_determine_end(&next, &prev, align) - end; | |
2555 | ||
2556 | while (true) { | |
2557 | BUG_ON(next && next->va_end <= base + end); | |
2558 | BUG_ON(prev && prev->va_end > base + end); | |
2559 | ||
2560 | /* | |
2561 | * base might have underflowed, add last_end before | |
2562 | * comparing. | |
2563 | */ | |
2564 | if (base + last_end < vmalloc_start + last_end) { | |
2565 | spin_unlock(&vmap_area_lock); | |
2566 | if (!purged) { | |
2567 | purge_vmap_area_lazy(); | |
2568 | purged = true; | |
2569 | goto retry; | |
2570 | } | |
2571 | goto err_free; | |
2572 | } | |
2573 | ||
2574 | /* | |
2575 | * If next overlaps, move base downwards so that it's | |
2576 | * right below next and then recheck. | |
2577 | */ | |
2578 | if (next && next->va_start < base + end) { | |
2579 | base = pvm_determine_end(&next, &prev, align) - end; | |
2580 | term_area = area; | |
2581 | continue; | |
2582 | } | |
2583 | ||
2584 | /* | |
2585 | * If prev overlaps, shift down next and prev and move | |
2586 | * base so that it's right below new next and then | |
2587 | * recheck. | |
2588 | */ | |
2589 | if (prev && prev->va_end > base + start) { | |
2590 | next = prev; | |
2591 | prev = node_to_va(rb_prev(&next->rb_node)); | |
2592 | base = pvm_determine_end(&next, &prev, align) - end; | |
2593 | term_area = area; | |
2594 | continue; | |
2595 | } | |
2596 | ||
2597 | /* | |
2598 | * This area fits, move on to the previous one. If | |
2599 | * the previous one is the terminal one, we're done. | |
2600 | */ | |
2601 | area = (area + nr_vms - 1) % nr_vms; | |
2602 | if (area == term_area) | |
2603 | break; | |
2604 | start = offsets[area]; | |
2605 | end = start + sizes[area]; | |
2606 | pvm_find_next_prev(base + end, &next, &prev); | |
2607 | } | |
2608 | found: | |
2609 | /* we've found a fitting base, insert all va's */ | |
2610 | for (area = 0; area < nr_vms; area++) { | |
2611 | struct vmap_area *va = vas[area]; | |
2612 | ||
2613 | va->va_start = base + offsets[area]; | |
2614 | va->va_end = va->va_start + sizes[area]; | |
2615 | __insert_vmap_area(va); | |
2616 | } | |
2617 | ||
2618 | vmap_area_pcpu_hole = base + offsets[last_area]; | |
2619 | ||
2620 | spin_unlock(&vmap_area_lock); | |
2621 | ||
2622 | /* insert all vm's */ | |
2623 | for (area = 0; area < nr_vms; area++) | |
2624 | setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC, | |
2625 | pcpu_get_vm_areas); | |
2626 | ||
2627 | kfree(vas); | |
2628 | return vms; | |
2629 | ||
2630 | err_free: | |
2631 | for (area = 0; area < nr_vms; area++) { | |
2632 | kfree(vas[area]); | |
2633 | kfree(vms[area]); | |
2634 | } | |
2635 | err_free2: | |
2636 | kfree(vas); | |
2637 | kfree(vms); | |
2638 | return NULL; | |
2639 | } | |
2640 | ||
2641 | /** | |
2642 | * pcpu_free_vm_areas - free vmalloc areas for percpu allocator | |
2643 | * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() | |
2644 | * @nr_vms: the number of allocated areas | |
2645 | * | |
2646 | * Free vm_structs and the array allocated by pcpu_get_vm_areas(). | |
2647 | */ | |
2648 | void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) | |
2649 | { | |
2650 | int i; | |
2651 | ||
2652 | for (i = 0; i < nr_vms; i++) | |
2653 | free_vm_area(vms[i]); | |
2654 | kfree(vms); | |
2655 | } | |
2656 | #endif /* CONFIG_SMP */ | |
2657 | ||
2658 | #ifdef CONFIG_PROC_FS | |
2659 | static void *s_start(struct seq_file *m, loff_t *pos) | |
2660 | __acquires(&vmap_area_lock) | |
2661 | { | |
2662 | spin_lock(&vmap_area_lock); | |
2663 | return seq_list_start(&vmap_area_list, *pos); | |
2664 | } | |
2665 | ||
2666 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
2667 | { | |
2668 | return seq_list_next(p, &vmap_area_list, pos); | |
2669 | } | |
2670 | ||
2671 | static void s_stop(struct seq_file *m, void *p) | |
2672 | __releases(&vmap_area_lock) | |
2673 | { | |
2674 | spin_unlock(&vmap_area_lock); | |
2675 | } | |
2676 | ||
2677 | static void show_numa_info(struct seq_file *m, struct vm_struct *v) | |
2678 | { | |
2679 | if (IS_ENABLED(CONFIG_NUMA)) { | |
2680 | unsigned int nr, *counters = m->private; | |
2681 | ||
2682 | if (!counters) | |
2683 | return; | |
2684 | ||
2685 | if (v->flags & VM_UNINITIALIZED) | |
2686 | return; | |
2687 | /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ | |
2688 | smp_rmb(); | |
2689 | ||
2690 | memset(counters, 0, nr_node_ids * sizeof(unsigned int)); | |
2691 | ||
2692 | for (nr = 0; nr < v->nr_pages; nr++) | |
2693 | counters[page_to_nid(v->pages[nr])]++; | |
2694 | ||
2695 | for_each_node_state(nr, N_HIGH_MEMORY) | |
2696 | if (counters[nr]) | |
2697 | seq_printf(m, " N%u=%u", nr, counters[nr]); | |
2698 | } | |
2699 | } | |
2700 | ||
2701 | static int s_show(struct seq_file *m, void *p) | |
2702 | { | |
2703 | struct vmap_area *va; | |
2704 | struct vm_struct *v; | |
2705 | ||
2706 | va = list_entry(p, struct vmap_area, list); | |
2707 | ||
2708 | /* | |
2709 | * s_show can encounter race with remove_vm_area, !VM_VM_AREA on | |
2710 | * behalf of vmap area is being tear down or vm_map_ram allocation. | |
2711 | */ | |
2712 | if (!(va->flags & VM_VM_AREA)) { | |
2713 | seq_printf(m, "0x%pK-0x%pK %7ld %s\n", | |
2714 | (void *)va->va_start, (void *)va->va_end, | |
2715 | va->va_end - va->va_start, | |
2716 | va->flags & VM_LAZY_FREE ? "unpurged vm_area" : "vm_map_ram"); | |
2717 | ||
2718 | return 0; | |
2719 | } | |
2720 | ||
2721 | v = va->vm; | |
2722 | ||
2723 | seq_printf(m, "0x%pK-0x%pK %7ld", | |
2724 | v->addr, v->addr + v->size, v->size); | |
2725 | ||
2726 | if (v->caller) | |
2727 | seq_printf(m, " %pS", v->caller); | |
2728 | ||
2729 | if (v->nr_pages) | |
2730 | seq_printf(m, " pages=%d", v->nr_pages); | |
2731 | ||
2732 | if (v->phys_addr) | |
2733 | seq_printf(m, " phys=%pa", &v->phys_addr); | |
2734 | ||
2735 | if (v->flags & VM_IOREMAP) | |
2736 | seq_puts(m, " ioremap"); | |
2737 | ||
2738 | if (v->flags & VM_ALLOC) | |
2739 | seq_puts(m, " vmalloc"); | |
2740 | ||
2741 | if (v->flags & VM_MAP) | |
2742 | seq_puts(m, " vmap"); | |
2743 | ||
2744 | if (v->flags & VM_USERMAP) | |
2745 | seq_puts(m, " user"); | |
2746 | ||
2747 | if (is_vmalloc_addr(v->pages)) | |
2748 | seq_puts(m, " vpages"); | |
2749 | ||
2750 | show_numa_info(m, v); | |
2751 | seq_putc(m, '\n'); | |
2752 | return 0; | |
2753 | } | |
2754 | ||
2755 | static const struct seq_operations vmalloc_op = { | |
2756 | .start = s_start, | |
2757 | .next = s_next, | |
2758 | .stop = s_stop, | |
2759 | .show = s_show, | |
2760 | }; | |
2761 | ||
2762 | static int vmalloc_open(struct inode *inode, struct file *file) | |
2763 | { | |
2764 | if (IS_ENABLED(CONFIG_NUMA)) | |
2765 | return seq_open_private(file, &vmalloc_op, | |
2766 | nr_node_ids * sizeof(unsigned int)); | |
2767 | else | |
2768 | return seq_open(file, &vmalloc_op); | |
2769 | } | |
2770 | ||
2771 | static const struct file_operations proc_vmalloc_operations = { | |
2772 | .open = vmalloc_open, | |
2773 | .read = seq_read, | |
2774 | .llseek = seq_lseek, | |
2775 | .release = seq_release_private, | |
2776 | }; | |
2777 | ||
2778 | static int __init proc_vmalloc_init(void) | |
2779 | { | |
2780 | proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations); | |
2781 | return 0; | |
2782 | } | |
2783 | module_init(proc_vmalloc_init); | |
2784 | ||
2785 | #endif | |
2786 |