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