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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(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(pfn, prot); | |
112 | ||
113 | entry = arch_make_huge_pte(entry, ilog2(size), 0); | |
114 | set_huge_pte_at(&init_mm, addr, pte, entry, size); | |
115 | pfn += PFN_DOWN(size); | |
116 | continue; | |
117 | } | |
118 | #endif | |
119 | set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); | |
120 | pfn++; | |
121 | } while (pte += PFN_DOWN(size), addr += size, addr != end); | |
122 | *mask |= PGTBL_PTE_MODIFIED; | |
123 | return 0; | |
124 | } | |
125 | ||
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_free_pte_page(pmd, addr)) | |
146 | return 0; | |
147 | ||
148 | return pmd_set_huge(pmd, 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(&init_mm, pud, addr, mask); | |
159 | if (!pmd) | |
160 | return -ENOMEM; | |
161 | do { | |
162 | next = pmd_addr_end(addr, end); | |
163 | ||
164 | if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot, | |
165 | max_page_shift)) { | |
166 | *mask |= PGTBL_PMD_MODIFIED; | |
167 | continue; | |
168 | } | |
169 | ||
170 | if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask)) | |
171 | return -ENOMEM; | |
172 | } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); | |
173 | return 0; | |
174 | } | |
175 | ||
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_free_pmd_page(pud, addr)) | |
196 | return 0; | |
197 | ||
198 | return pud_set_huge(pud, 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(&init_mm, p4d, addr, mask); | |
209 | if (!pud) | |
210 | return -ENOMEM; | |
211 | do { | |
212 | next = pud_addr_end(addr, end); | |
213 | ||
214 | if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot, | |
215 | max_page_shift)) { | |
216 | *mask |= PGTBL_PUD_MODIFIED; | |
217 | continue; | |
218 | } | |
219 | ||
220 | if (vmap_pmd_range(pud, addr, next, phys_addr, prot, | |
221 | max_page_shift, mask)) | |
222 | return -ENOMEM; | |
223 | } while (pud++, phys_addr += (next - addr), addr = next, addr != end); | |
224 | return 0; | |
225 | } | |
226 | ||
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_free_pud_page(p4d, addr)) | |
247 | return 0; | |
248 | ||
249 | return p4d_set_huge(p4d, 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(&init_mm, pgd, addr, mask); | |
260 | if (!p4d) | |
261 | return -ENOMEM; | |
262 | do { | |
263 | next = p4d_addr_end(addr, end); | |
264 | ||
265 | if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot, | |
266 | max_page_shift)) { | |
267 | *mask |= PGTBL_P4D_MODIFIED; | |
268 | continue; | |
269 | } | |
270 | ||
271 | if (vmap_pud_range(p4d, addr, next, phys_addr, prot, | |
272 | max_page_shift, mask)) | |
273 | return -ENOMEM; | |
274 | } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); | |
275 | return 0; | |
276 | } | |
277 | ||
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, next, phys_addr, prot, | |
296 | max_page_shift, &mask); | |
297 | if (err) | |
298 | break; | |
299 | } while (pgd++, phys_addr += (next - addr), addr = next, addr != end); | |
300 | ||
301 | if (mask & ARCH_PAGE_TABLE_SYNC_MASK) | |
302 | arch_sync_kernel_mappings(start, end); | |
303 | ||
304 | return err; | |
305 | } | |
306 | ||
307 | int vmap_page_range(unsigned long addr, unsigned long end, | |
308 | phys_addr_t phys_addr, pgprot_t prot) | |
309 | { | |
310 | int err; | |
311 | ||
312 | err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), | |
313 | ioremap_max_page_shift); | |
314 | flush_cache_vmap(addr, end); | |
315 | if (!err) | |
316 | err = kmsan_ioremap_page_range(addr, end, phys_addr, prot, | |
317 | ioremap_max_page_shift); | |
318 | return err; | |
319 | } | |
320 | ||
321 | int ioremap_page_range(unsigned long addr, unsigned long end, | |
322 | phys_addr_t phys_addr, pgprot_t prot) | |
323 | { | |
324 | struct vm_struct *area; | |
325 | ||
326 | area = find_vm_area((void *)addr); | |
327 | if (!area || !(area->flags & VM_IOREMAP)) { | |
328 | WARN_ONCE(1, "vm_area at addr %lx is not marked as VM_IOREMAP\n", addr); | |
329 | return -EINVAL; | |
330 | } | |
331 | if (addr != (unsigned long)area->addr || | |
332 | (void *)end != area->addr + get_vm_area_size(area)) { | |
333 | WARN_ONCE(1, "ioremap request [%lx,%lx) doesn't match vm_area [%lx, %lx)\n", | |
334 | addr, end, (long)area->addr, | |
335 | (long)area->addr + get_vm_area_size(area)); | |
336 | return -ERANGE; | |
337 | } | |
338 | return vmap_page_range(addr, end, phys_addr, prot); | |
339 | } | |
340 | ||
341 | static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, | |
342 | pgtbl_mod_mask *mask) | |
343 | { | |
344 | pte_t *pte; | |
345 | ||
346 | pte = pte_offset_kernel(pmd, addr); | |
347 | do { | |
348 | pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); | |
349 | WARN_ON(!pte_none(ptent) && !pte_present(ptent)); | |
350 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
351 | *mask |= PGTBL_PTE_MODIFIED; | |
352 | } | |
353 | ||
354 | static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, | |
355 | pgtbl_mod_mask *mask) | |
356 | { | |
357 | pmd_t *pmd; | |
358 | unsigned long next; | |
359 | int cleared; | |
360 | ||
361 | pmd = pmd_offset(pud, addr); | |
362 | do { | |
363 | next = pmd_addr_end(addr, end); | |
364 | ||
365 | cleared = pmd_clear_huge(pmd); | |
366 | if (cleared || pmd_bad(*pmd)) | |
367 | *mask |= PGTBL_PMD_MODIFIED; | |
368 | ||
369 | if (cleared) | |
370 | continue; | |
371 | if (pmd_none_or_clear_bad(pmd)) | |
372 | continue; | |
373 | vunmap_pte_range(pmd, addr, next, mask); | |
374 | ||
375 | cond_resched(); | |
376 | } while (pmd++, addr = next, addr != end); | |
377 | } | |
378 | ||
379 | static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, | |
380 | pgtbl_mod_mask *mask) | |
381 | { | |
382 | pud_t *pud; | |
383 | unsigned long next; | |
384 | int cleared; | |
385 | ||
386 | pud = pud_offset(p4d, addr); | |
387 | do { | |
388 | next = pud_addr_end(addr, end); | |
389 | ||
390 | cleared = pud_clear_huge(pud); | |
391 | if (cleared || pud_bad(*pud)) | |
392 | *mask |= PGTBL_PUD_MODIFIED; | |
393 | ||
394 | if (cleared) | |
395 | continue; | |
396 | if (pud_none_or_clear_bad(pud)) | |
397 | continue; | |
398 | vunmap_pmd_range(pud, addr, next, mask); | |
399 | } while (pud++, addr = next, addr != end); | |
400 | } | |
401 | ||
402 | static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, | |
403 | pgtbl_mod_mask *mask) | |
404 | { | |
405 | p4d_t *p4d; | |
406 | unsigned long next; | |
407 | ||
408 | p4d = p4d_offset(pgd, addr); | |
409 | do { | |
410 | next = p4d_addr_end(addr, end); | |
411 | ||
412 | p4d_clear_huge(p4d); | |
413 | if (p4d_bad(*p4d)) | |
414 | *mask |= PGTBL_P4D_MODIFIED; | |
415 | ||
416 | if (p4d_none_or_clear_bad(p4d)) | |
417 | continue; | |
418 | vunmap_pud_range(p4d, addr, next, mask); | |
419 | } while (p4d++, addr = next, addr != end); | |
420 | } | |
421 | ||
422 | /* | |
423 | * vunmap_range_noflush is similar to vunmap_range, but does not | |
424 | * flush caches or TLBs. | |
425 | * | |
426 | * The caller is responsible for calling flush_cache_vmap() before calling | |
427 | * this function, and flush_tlb_kernel_range after it has returned | |
428 | * successfully (and before the addresses are expected to cause a page fault | |
429 | * or be re-mapped for something else, if TLB flushes are being delayed or | |
430 | * coalesced). | |
431 | * | |
432 | * This is an internal function only. Do not use outside mm/. | |
433 | */ | |
434 | void __vunmap_range_noflush(unsigned long start, unsigned long end) | |
435 | { | |
436 | unsigned long next; | |
437 | pgd_t *pgd; | |
438 | unsigned long addr = start; | |
439 | pgtbl_mod_mask mask = 0; | |
440 | ||
441 | BUG_ON(addr >= end); | |
442 | pgd = pgd_offset_k(addr); | |
443 | do { | |
444 | next = pgd_addr_end(addr, end); | |
445 | if (pgd_bad(*pgd)) | |
446 | mask |= PGTBL_PGD_MODIFIED; | |
447 | if (pgd_none_or_clear_bad(pgd)) | |
448 | continue; | |
449 | vunmap_p4d_range(pgd, addr, next, &mask); | |
450 | } while (pgd++, addr = next, addr != end); | |
451 | ||
452 | if (mask & ARCH_PAGE_TABLE_SYNC_MASK) | |
453 | arch_sync_kernel_mappings(start, end); | |
454 | } | |
455 | ||
456 | void vunmap_range_noflush(unsigned long start, unsigned long end) | |
457 | { | |
458 | kmsan_vunmap_range_noflush(start, end); | |
459 | __vunmap_range_noflush(start, end); | |
460 | } | |
461 | ||
462 | /** | |
463 | * vunmap_range - unmap kernel virtual addresses | |
464 | * @addr: start of the VM area to unmap | |
465 | * @end: end of the VM area to unmap (non-inclusive) | |
466 | * | |
467 | * Clears any present PTEs in the virtual address range, flushes TLBs and | |
468 | * caches. Any subsequent access to the address before it has been re-mapped | |
469 | * is a kernel bug. | |
470 | */ | |
471 | void vunmap_range(unsigned long addr, unsigned long end) | |
472 | { | |
473 | flush_cache_vunmap(addr, end); | |
474 | vunmap_range_noflush(addr, end); | |
475 | flush_tlb_kernel_range(addr, end); | |
476 | } | |
477 | ||
478 | static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr, | |
479 | unsigned long end, pgprot_t prot, struct page **pages, int *nr, | |
480 | pgtbl_mod_mask *mask) | |
481 | { | |
482 | pte_t *pte; | |
483 | ||
484 | /* | |
485 | * nr is a running index into the array which helps higher level | |
486 | * callers keep track of where we're up to. | |
487 | */ | |
488 | ||
489 | pte = pte_alloc_kernel_track(pmd, addr, mask); | |
490 | if (!pte) | |
491 | return -ENOMEM; | |
492 | do { | |
493 | struct page *page = pages[*nr]; | |
494 | ||
495 | if (WARN_ON(!pte_none(ptep_get(pte)))) | |
496 | return -EBUSY; | |
497 | if (WARN_ON(!page)) | |
498 | return -ENOMEM; | |
499 | if (WARN_ON(!pfn_valid(page_to_pfn(page)))) | |
500 | return -EINVAL; | |
501 | ||
502 | set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); | |
503 | (*nr)++; | |
504 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
505 | *mask |= PGTBL_PTE_MODIFIED; | |
506 | return 0; | |
507 | } | |
508 | ||
509 | static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr, | |
510 | unsigned long end, pgprot_t prot, struct page **pages, int *nr, | |
511 | pgtbl_mod_mask *mask) | |
512 | { | |
513 | pmd_t *pmd; | |
514 | unsigned long next; | |
515 | ||
516 | pmd = pmd_alloc_track(&init_mm, pud, addr, mask); | |
517 | if (!pmd) | |
518 | return -ENOMEM; | |
519 | do { | |
520 | next = pmd_addr_end(addr, end); | |
521 | if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask)) | |
522 | return -ENOMEM; | |
523 | } while (pmd++, addr = next, addr != end); | |
524 | return 0; | |
525 | } | |
526 | ||
527 | static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr, | |
528 | unsigned long end, pgprot_t prot, struct page **pages, int *nr, | |
529 | pgtbl_mod_mask *mask) | |
530 | { | |
531 | pud_t *pud; | |
532 | unsigned long next; | |
533 | ||
534 | pud = pud_alloc_track(&init_mm, p4d, addr, mask); | |
535 | if (!pud) | |
536 | return -ENOMEM; | |
537 | do { | |
538 | next = pud_addr_end(addr, end); | |
539 | if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask)) | |
540 | return -ENOMEM; | |
541 | } while (pud++, addr = next, addr != end); | |
542 | return 0; | |
543 | } | |
544 | ||
545 | static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr, | |
546 | unsigned long end, pgprot_t prot, struct page **pages, int *nr, | |
547 | pgtbl_mod_mask *mask) | |
548 | { | |
549 | p4d_t *p4d; | |
550 | unsigned long next; | |
551 | ||
552 | p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); | |
553 | if (!p4d) | |
554 | return -ENOMEM; | |
555 | do { | |
556 | next = p4d_addr_end(addr, end); | |
557 | if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask)) | |
558 | return -ENOMEM; | |
559 | } while (p4d++, addr = next, addr != end); | |
560 | return 0; | |
561 | } | |
562 | ||
563 | static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, | |
564 | pgprot_t prot, struct page **pages) | |
565 | { | |
566 | unsigned long start = addr; | |
567 | pgd_t *pgd; | |
568 | unsigned long next; | |
569 | int err = 0; | |
570 | int nr = 0; | |
571 | pgtbl_mod_mask mask = 0; | |
572 | ||
573 | BUG_ON(addr >= end); | |
574 | pgd = pgd_offset_k(addr); | |
575 | do { | |
576 | next = pgd_addr_end(addr, end); | |
577 | if (pgd_bad(*pgd)) | |
578 | mask |= PGTBL_PGD_MODIFIED; | |
579 | err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask); | |
580 | if (err) | |
581 | return err; | |
582 | } while (pgd++, addr = next, addr != end); | |
583 | ||
584 | if (mask & ARCH_PAGE_TABLE_SYNC_MASK) | |
585 | arch_sync_kernel_mappings(start, end); | |
586 | ||
587 | return 0; | |
588 | } | |
589 | ||
590 | /* | |
591 | * vmap_pages_range_noflush is similar to vmap_pages_range, but does not | |
592 | * flush caches. | |
593 | * | |
594 | * The caller is responsible for calling flush_cache_vmap() after this | |
595 | * function returns successfully and before the addresses are accessed. | |
596 | * | |
597 | * This is an internal function only. Do not use outside mm/. | |
598 | */ | |
599 | int __vmap_pages_range_noflush(unsigned long addr, unsigned long end, | |
600 | pgprot_t prot, struct page **pages, unsigned int page_shift) | |
601 | { | |
602 | unsigned int i, nr = (end - addr) >> PAGE_SHIFT; | |
603 | ||
604 | WARN_ON(page_shift < PAGE_SHIFT); | |
605 | ||
606 | if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || | |
607 | page_shift == PAGE_SHIFT) | |
608 | return vmap_small_pages_range_noflush(addr, end, prot, pages); | |
609 | ||
610 | for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) { | |
611 | int err; | |
612 | ||
613 | err = vmap_range_noflush(addr, addr + (1UL << page_shift), | |
614 | page_to_phys(pages[i]), prot, | |
615 | page_shift); | |
616 | if (err) | |
617 | return err; | |
618 | ||
619 | addr += 1UL << page_shift; | |
620 | } | |
621 | ||
622 | return 0; | |
623 | } | |
624 | ||
625 | int vmap_pages_range_noflush(unsigned long addr, unsigned long end, | |
626 | pgprot_t prot, struct page **pages, unsigned int page_shift) | |
627 | { | |
628 | int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages, | |
629 | page_shift); | |
630 | ||
631 | if (ret) | |
632 | return ret; | |
633 | return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift); | |
634 | } | |
635 | ||
636 | /** | |
637 | * vmap_pages_range - map pages to a kernel virtual address | |
638 | * @addr: start of the VM area to map | |
639 | * @end: end of the VM area to map (non-inclusive) | |
640 | * @prot: page protection flags to use | |
641 | * @pages: pages to map (always PAGE_SIZE pages) | |
642 | * @page_shift: maximum shift that the pages may be mapped with, @pages must | |
643 | * be aligned and contiguous up to at least this shift. | |
644 | * | |
645 | * RETURNS: | |
646 | * 0 on success, -errno on failure. | |
647 | */ | |
648 | static int vmap_pages_range(unsigned long addr, unsigned long end, | |
649 | pgprot_t prot, struct page **pages, unsigned int page_shift) | |
650 | { | |
651 | int err; | |
652 | ||
653 | err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift); | |
654 | flush_cache_vmap(addr, end); | |
655 | return err; | |
656 | } | |
657 | ||
658 | static int check_sparse_vm_area(struct vm_struct *area, unsigned long start, | |
659 | unsigned long end) | |
660 | { | |
661 | might_sleep(); | |
662 | if (WARN_ON_ONCE(area->flags & VM_FLUSH_RESET_PERMS)) | |
663 | return -EINVAL; | |
664 | if (WARN_ON_ONCE(area->flags & VM_NO_GUARD)) | |
665 | return -EINVAL; | |
666 | if (WARN_ON_ONCE(!(area->flags & VM_SPARSE))) | |
667 | return -EINVAL; | |
668 | if ((end - start) >> PAGE_SHIFT > totalram_pages()) | |
669 | return -E2BIG; | |
670 | if (start < (unsigned long)area->addr || | |
671 | (void *)end > area->addr + get_vm_area_size(area)) | |
672 | return -ERANGE; | |
673 | return 0; | |
674 | } | |
675 | ||
676 | /** | |
677 | * vm_area_map_pages - map pages inside given sparse vm_area | |
678 | * @area: vm_area | |
679 | * @start: start address inside vm_area | |
680 | * @end: end address inside vm_area | |
681 | * @pages: pages to map (always PAGE_SIZE pages) | |
682 | */ | |
683 | int vm_area_map_pages(struct vm_struct *area, unsigned long start, | |
684 | unsigned long end, struct page **pages) | |
685 | { | |
686 | int err; | |
687 | ||
688 | err = check_sparse_vm_area(area, start, end); | |
689 | if (err) | |
690 | return err; | |
691 | ||
692 | return vmap_pages_range(start, end, PAGE_KERNEL, pages, PAGE_SHIFT); | |
693 | } | |
694 | ||
695 | /** | |
696 | * vm_area_unmap_pages - unmap pages inside given sparse vm_area | |
697 | * @area: vm_area | |
698 | * @start: start address inside vm_area | |
699 | * @end: end address inside vm_area | |
700 | */ | |
701 | void vm_area_unmap_pages(struct vm_struct *area, unsigned long start, | |
702 | unsigned long end) | |
703 | { | |
704 | if (check_sparse_vm_area(area, start, end)) | |
705 | return; | |
706 | ||
707 | vunmap_range(start, end); | |
708 | } | |
709 | ||
710 | int is_vmalloc_or_module_addr(const void *x) | |
711 | { | |
712 | /* | |
713 | * ARM, x86-64 and sparc64 put modules in a special place, | |
714 | * and fall back on vmalloc() if that fails. Others | |
715 | * just put it in the vmalloc space. | |
716 | */ | |
717 | #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) | |
718 | unsigned long addr = (unsigned long)kasan_reset_tag(x); | |
719 | if (addr >= MODULES_VADDR && addr < MODULES_END) | |
720 | return 1; | |
721 | #endif | |
722 | return is_vmalloc_addr(x); | |
723 | } | |
724 | EXPORT_SYMBOL_GPL(is_vmalloc_or_module_addr); | |
725 | ||
726 | /* | |
727 | * Walk a vmap address to the struct page it maps. Huge vmap mappings will | |
728 | * return the tail page that corresponds to the base page address, which | |
729 | * matches small vmap mappings. | |
730 | */ | |
731 | struct page *vmalloc_to_page(const void *vmalloc_addr) | |
732 | { | |
733 | unsigned long addr = (unsigned long) vmalloc_addr; | |
734 | struct page *page = NULL; | |
735 | pgd_t *pgd = pgd_offset_k(addr); | |
736 | p4d_t *p4d; | |
737 | pud_t *pud; | |
738 | pmd_t *pmd; | |
739 | pte_t *ptep, pte; | |
740 | ||
741 | /* | |
742 | * XXX we might need to change this if we add VIRTUAL_BUG_ON for | |
743 | * architectures that do not vmalloc module space | |
744 | */ | |
745 | VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr)); | |
746 | ||
747 | if (pgd_none(*pgd)) | |
748 | return NULL; | |
749 | if (WARN_ON_ONCE(pgd_leaf(*pgd))) | |
750 | return NULL; /* XXX: no allowance for huge pgd */ | |
751 | if (WARN_ON_ONCE(pgd_bad(*pgd))) | |
752 | return NULL; | |
753 | ||
754 | p4d = p4d_offset(pgd, addr); | |
755 | if (p4d_none(*p4d)) | |
756 | return NULL; | |
757 | if (p4d_leaf(*p4d)) | |
758 | return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT); | |
759 | if (WARN_ON_ONCE(p4d_bad(*p4d))) | |
760 | return NULL; | |
761 | ||
762 | pud = pud_offset(p4d, addr); | |
763 | if (pud_none(*pud)) | |
764 | return NULL; | |
765 | if (pud_leaf(*pud)) | |
766 | return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); | |
767 | if (WARN_ON_ONCE(pud_bad(*pud))) | |
768 | return NULL; | |
769 | ||
770 | pmd = pmd_offset(pud, addr); | |
771 | if (pmd_none(*pmd)) | |
772 | return NULL; | |
773 | if (pmd_leaf(*pmd)) | |
774 | return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); | |
775 | if (WARN_ON_ONCE(pmd_bad(*pmd))) | |
776 | return NULL; | |
777 | ||
778 | ptep = pte_offset_kernel(pmd, addr); | |
779 | pte = ptep_get(ptep); | |
780 | if (pte_present(pte)) | |
781 | page = pte_page(pte); | |
782 | ||
783 | return page; | |
784 | } | |
785 | EXPORT_SYMBOL(vmalloc_to_page); | |
786 | ||
787 | /* | |
788 | * Map a vmalloc()-space virtual address to the physical page frame number. | |
789 | */ | |
790 | unsigned long vmalloc_to_pfn(const void *vmalloc_addr) | |
791 | { | |
792 | return page_to_pfn(vmalloc_to_page(vmalloc_addr)); | |
793 | } | |
794 | EXPORT_SYMBOL(vmalloc_to_pfn); | |
795 | ||
796 | ||
797 | /*** Global kva allocator ***/ | |
798 | ||
799 | #define DEBUG_AUGMENT_PROPAGATE_CHECK 0 | |
800 | #define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0 | |
801 | ||
802 | ||
803 | static DEFINE_SPINLOCK(free_vmap_area_lock); | |
804 | static bool vmap_initialized __read_mostly; | |
805 | ||
806 | /* | |
807 | * This kmem_cache is used for vmap_area objects. Instead of | |
808 | * allocating from slab we reuse an object from this cache to | |
809 | * make things faster. Especially in "no edge" splitting of | |
810 | * free block. | |
811 | */ | |
812 | static struct kmem_cache *vmap_area_cachep; | |
813 | ||
814 | /* | |
815 | * This linked list is used in pair with free_vmap_area_root. | |
816 | * It gives O(1) access to prev/next to perform fast coalescing. | |
817 | */ | |
818 | static LIST_HEAD(free_vmap_area_list); | |
819 | ||
820 | /* | |
821 | * This augment red-black tree represents the free vmap space. | |
822 | * All vmap_area objects in this tree are sorted by va->va_start | |
823 | * address. It is used for allocation and merging when a vmap | |
824 | * object is released. | |
825 | * | |
826 | * Each vmap_area node contains a maximum available free block | |
827 | * of its sub-tree, right or left. Therefore it is possible to | |
828 | * find a lowest match of free area. | |
829 | */ | |
830 | static struct rb_root free_vmap_area_root = RB_ROOT; | |
831 | ||
832 | /* | |
833 | * Preload a CPU with one object for "no edge" split case. The | |
834 | * aim is to get rid of allocations from the atomic context, thus | |
835 | * to use more permissive allocation masks. | |
836 | */ | |
837 | static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node); | |
838 | ||
839 | /* | |
840 | * This structure defines a single, solid model where a list and | |
841 | * rb-tree are part of one entity protected by the lock. Nodes are | |
842 | * sorted in ascending order, thus for O(1) access to left/right | |
843 | * neighbors a list is used as well as for sequential traversal. | |
844 | */ | |
845 | struct rb_list { | |
846 | struct rb_root root; | |
847 | struct list_head head; | |
848 | spinlock_t lock; | |
849 | }; | |
850 | ||
851 | /* | |
852 | * A fast size storage contains VAs up to 1M size. A pool consists | |
853 | * of linked between each other ready to go VAs of certain sizes. | |
854 | * An index in the pool-array corresponds to number of pages + 1. | |
855 | */ | |
856 | #define MAX_VA_SIZE_PAGES 256 | |
857 | ||
858 | struct vmap_pool { | |
859 | struct list_head head; | |
860 | unsigned long len; | |
861 | }; | |
862 | ||
863 | /* | |
864 | * An effective vmap-node logic. Users make use of nodes instead | |
865 | * of a global heap. It allows to balance an access and mitigate | |
866 | * contention. | |
867 | */ | |
868 | static struct vmap_node { | |
869 | /* Simple size segregated storage. */ | |
870 | struct vmap_pool pool[MAX_VA_SIZE_PAGES]; | |
871 | spinlock_t pool_lock; | |
872 | bool skip_populate; | |
873 | ||
874 | /* Bookkeeping data of this node. */ | |
875 | struct rb_list busy; | |
876 | struct rb_list lazy; | |
877 | ||
878 | /* | |
879 | * Ready-to-free areas. | |
880 | */ | |
881 | struct list_head purge_list; | |
882 | struct work_struct purge_work; | |
883 | unsigned long nr_purged; | |
884 | } single; | |
885 | ||
886 | /* | |
887 | * Initial setup consists of one single node, i.e. a balancing | |
888 | * is fully disabled. Later on, after vmap is initialized these | |
889 | * parameters are updated based on a system capacity. | |
890 | */ | |
891 | static struct vmap_node *vmap_nodes = &single; | |
892 | static __read_mostly unsigned int nr_vmap_nodes = 1; | |
893 | static __read_mostly unsigned int vmap_zone_size = 1; | |
894 | ||
895 | static inline unsigned int | |
896 | addr_to_node_id(unsigned long addr) | |
897 | { | |
898 | return (addr / vmap_zone_size) % nr_vmap_nodes; | |
899 | } | |
900 | ||
901 | static inline struct vmap_node * | |
902 | addr_to_node(unsigned long addr) | |
903 | { | |
904 | return &vmap_nodes[addr_to_node_id(addr)]; | |
905 | } | |
906 | ||
907 | static inline struct vmap_node * | |
908 | id_to_node(unsigned int id) | |
909 | { | |
910 | return &vmap_nodes[id % nr_vmap_nodes]; | |
911 | } | |
912 | ||
913 | /* | |
914 | * We use the value 0 to represent "no node", that is why | |
915 | * an encoded value will be the node-id incremented by 1. | |
916 | * It is always greater then 0. A valid node_id which can | |
917 | * be encoded is [0:nr_vmap_nodes - 1]. If a passed node_id | |
918 | * is not valid 0 is returned. | |
919 | */ | |
920 | static unsigned int | |
921 | encode_vn_id(unsigned int node_id) | |
922 | { | |
923 | /* Can store U8_MAX [0:254] nodes. */ | |
924 | if (node_id < nr_vmap_nodes) | |
925 | return (node_id + 1) << BITS_PER_BYTE; | |
926 | ||
927 | /* Warn and no node encoded. */ | |
928 | WARN_ONCE(1, "Encode wrong node id (%u)\n", node_id); | |
929 | return 0; | |
930 | } | |
931 | ||
932 | /* | |
933 | * Returns an encoded node-id, the valid range is within | |
934 | * [0:nr_vmap_nodes-1] values. Otherwise nr_vmap_nodes is | |
935 | * returned if extracted data is wrong. | |
936 | */ | |
937 | static unsigned int | |
938 | decode_vn_id(unsigned int val) | |
939 | { | |
940 | unsigned int node_id = (val >> BITS_PER_BYTE) - 1; | |
941 | ||
942 | /* Can store U8_MAX [0:254] nodes. */ | |
943 | if (node_id < nr_vmap_nodes) | |
944 | return node_id; | |
945 | ||
946 | /* If it was _not_ zero, warn. */ | |
947 | WARN_ONCE(node_id != UINT_MAX, | |
948 | "Decode wrong node id (%d)\n", node_id); | |
949 | ||
950 | return nr_vmap_nodes; | |
951 | } | |
952 | ||
953 | static bool | |
954 | is_vn_id_valid(unsigned int node_id) | |
955 | { | |
956 | if (node_id < nr_vmap_nodes) | |
957 | return true; | |
958 | ||
959 | return false; | |
960 | } | |
961 | ||
962 | static __always_inline unsigned long | |
963 | va_size(struct vmap_area *va) | |
964 | { | |
965 | return (va->va_end - va->va_start); | |
966 | } | |
967 | ||
968 | static __always_inline unsigned long | |
969 | get_subtree_max_size(struct rb_node *node) | |
970 | { | |
971 | struct vmap_area *va; | |
972 | ||
973 | va = rb_entry_safe(node, struct vmap_area, rb_node); | |
974 | return va ? va->subtree_max_size : 0; | |
975 | } | |
976 | ||
977 | RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb, | |
978 | struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size) | |
979 | ||
980 | static void reclaim_and_purge_vmap_areas(void); | |
981 | static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); | |
982 | static void drain_vmap_area_work(struct work_struct *work); | |
983 | static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work); | |
984 | ||
985 | static atomic_long_t nr_vmalloc_pages; | |
986 | ||
987 | unsigned long vmalloc_nr_pages(void) | |
988 | { | |
989 | return atomic_long_read(&nr_vmalloc_pages); | |
990 | } | |
991 | ||
992 | static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root) | |
993 | { | |
994 | struct rb_node *n = root->rb_node; | |
995 | ||
996 | addr = (unsigned long)kasan_reset_tag((void *)addr); | |
997 | ||
998 | while (n) { | |
999 | struct vmap_area *va; | |
1000 | ||
1001 | va = rb_entry(n, struct vmap_area, rb_node); | |
1002 | if (addr < va->va_start) | |
1003 | n = n->rb_left; | |
1004 | else if (addr >= va->va_end) | |
1005 | n = n->rb_right; | |
1006 | else | |
1007 | return va; | |
1008 | } | |
1009 | ||
1010 | return NULL; | |
1011 | } | |
1012 | ||
1013 | /* Look up the first VA which satisfies addr < va_end, NULL if none. */ | |
1014 | static struct vmap_area * | |
1015 | __find_vmap_area_exceed_addr(unsigned long addr, struct rb_root *root) | |
1016 | { | |
1017 | struct vmap_area *va = NULL; | |
1018 | struct rb_node *n = root->rb_node; | |
1019 | ||
1020 | addr = (unsigned long)kasan_reset_tag((void *)addr); | |
1021 | ||
1022 | while (n) { | |
1023 | struct vmap_area *tmp; | |
1024 | ||
1025 | tmp = rb_entry(n, struct vmap_area, rb_node); | |
1026 | if (tmp->va_end > addr) { | |
1027 | va = tmp; | |
1028 | if (tmp->va_start <= addr) | |
1029 | break; | |
1030 | ||
1031 | n = n->rb_left; | |
1032 | } else | |
1033 | n = n->rb_right; | |
1034 | } | |
1035 | ||
1036 | return va; | |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * Returns a node where a first VA, that satisfies addr < va_end, resides. | |
1041 | * If success, a node is locked. A user is responsible to unlock it when a | |
1042 | * VA is no longer needed to be accessed. | |
1043 | * | |
1044 | * Returns NULL if nothing found. | |
1045 | */ | |
1046 | static struct vmap_node * | |
1047 | find_vmap_area_exceed_addr_lock(unsigned long addr, struct vmap_area **va) | |
1048 | { | |
1049 | unsigned long va_start_lowest; | |
1050 | struct vmap_node *vn; | |
1051 | int i; | |
1052 | ||
1053 | repeat: | |
1054 | for (i = 0, va_start_lowest = 0; i < nr_vmap_nodes; i++) { | |
1055 | vn = &vmap_nodes[i]; | |
1056 | ||
1057 | spin_lock(&vn->busy.lock); | |
1058 | *va = __find_vmap_area_exceed_addr(addr, &vn->busy.root); | |
1059 | ||
1060 | if (*va) | |
1061 | if (!va_start_lowest || (*va)->va_start < va_start_lowest) | |
1062 | va_start_lowest = (*va)->va_start; | |
1063 | spin_unlock(&vn->busy.lock); | |
1064 | } | |
1065 | ||
1066 | /* | |
1067 | * Check if found VA exists, it might have gone away. In this case we | |
1068 | * repeat the search because a VA has been removed concurrently and we | |
1069 | * need to proceed to the next one, which is a rare case. | |
1070 | */ | |
1071 | if (va_start_lowest) { | |
1072 | vn = addr_to_node(va_start_lowest); | |
1073 | ||
1074 | spin_lock(&vn->busy.lock); | |
1075 | *va = __find_vmap_area(va_start_lowest, &vn->busy.root); | |
1076 | ||
1077 | if (*va) | |
1078 | return vn; | |
1079 | ||
1080 | spin_unlock(&vn->busy.lock); | |
1081 | goto repeat; | |
1082 | } | |
1083 | ||
1084 | return NULL; | |
1085 | } | |
1086 | ||
1087 | /* | |
1088 | * This function returns back addresses of parent node | |
1089 | * and its left or right link for further processing. | |
1090 | * | |
1091 | * Otherwise NULL is returned. In that case all further | |
1092 | * steps regarding inserting of conflicting overlap range | |
1093 | * have to be declined and actually considered as a bug. | |
1094 | */ | |
1095 | static __always_inline struct rb_node ** | |
1096 | find_va_links(struct vmap_area *va, | |
1097 | struct rb_root *root, struct rb_node *from, | |
1098 | struct rb_node **parent) | |
1099 | { | |
1100 | struct vmap_area *tmp_va; | |
1101 | struct rb_node **link; | |
1102 | ||
1103 | if (root) { | |
1104 | link = &root->rb_node; | |
1105 | if (unlikely(!*link)) { | |
1106 | *parent = NULL; | |
1107 | return link; | |
1108 | } | |
1109 | } else { | |
1110 | link = &from; | |
1111 | } | |
1112 | ||
1113 | /* | |
1114 | * Go to the bottom of the tree. When we hit the last point | |
1115 | * we end up with parent rb_node and correct direction, i name | |
1116 | * it link, where the new va->rb_node will be attached to. | |
1117 | */ | |
1118 | do { | |
1119 | tmp_va = rb_entry(*link, struct vmap_area, rb_node); | |
1120 | ||
1121 | /* | |
1122 | * During the traversal we also do some sanity check. | |
1123 | * Trigger the BUG() if there are sides(left/right) | |
1124 | * or full overlaps. | |
1125 | */ | |
1126 | if (va->va_end <= tmp_va->va_start) | |
1127 | link = &(*link)->rb_left; | |
1128 | else if (va->va_start >= tmp_va->va_end) | |
1129 | link = &(*link)->rb_right; | |
1130 | else { | |
1131 | WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n", | |
1132 | va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end); | |
1133 | ||
1134 | return NULL; | |
1135 | } | |
1136 | } while (*link); | |
1137 | ||
1138 | *parent = &tmp_va->rb_node; | |
1139 | return link; | |
1140 | } | |
1141 | ||
1142 | static __always_inline struct list_head * | |
1143 | get_va_next_sibling(struct rb_node *parent, struct rb_node **link) | |
1144 | { | |
1145 | struct list_head *list; | |
1146 | ||
1147 | if (unlikely(!parent)) | |
1148 | /* | |
1149 | * The red-black tree where we try to find VA neighbors | |
1150 | * before merging or inserting is empty, i.e. it means | |
1151 | * there is no free vmap space. Normally it does not | |
1152 | * happen but we handle this case anyway. | |
1153 | */ | |
1154 | return NULL; | |
1155 | ||
1156 | list = &rb_entry(parent, struct vmap_area, rb_node)->list; | |
1157 | return (&parent->rb_right == link ? list->next : list); | |
1158 | } | |
1159 | ||
1160 | static __always_inline void | |
1161 | __link_va(struct vmap_area *va, struct rb_root *root, | |
1162 | struct rb_node *parent, struct rb_node **link, | |
1163 | struct list_head *head, bool augment) | |
1164 | { | |
1165 | /* | |
1166 | * VA is still not in the list, but we can | |
1167 | * identify its future previous list_head node. | |
1168 | */ | |
1169 | if (likely(parent)) { | |
1170 | head = &rb_entry(parent, struct vmap_area, rb_node)->list; | |
1171 | if (&parent->rb_right != link) | |
1172 | head = head->prev; | |
1173 | } | |
1174 | ||
1175 | /* Insert to the rb-tree */ | |
1176 | rb_link_node(&va->rb_node, parent, link); | |
1177 | if (augment) { | |
1178 | /* | |
1179 | * Some explanation here. Just perform simple insertion | |
1180 | * to the tree. We do not set va->subtree_max_size to | |
1181 | * its current size before calling rb_insert_augmented(). | |
1182 | * It is because we populate the tree from the bottom | |
1183 | * to parent levels when the node _is_ in the tree. | |
1184 | * | |
1185 | * Therefore we set subtree_max_size to zero after insertion, | |
1186 | * to let __augment_tree_propagate_from() puts everything to | |
1187 | * the correct order later on. | |
1188 | */ | |
1189 | rb_insert_augmented(&va->rb_node, | |
1190 | root, &free_vmap_area_rb_augment_cb); | |
1191 | va->subtree_max_size = 0; | |
1192 | } else { | |
1193 | rb_insert_color(&va->rb_node, root); | |
1194 | } | |
1195 | ||
1196 | /* Address-sort this list */ | |
1197 | list_add(&va->list, head); | |
1198 | } | |
1199 | ||
1200 | static __always_inline void | |
1201 | link_va(struct vmap_area *va, struct rb_root *root, | |
1202 | struct rb_node *parent, struct rb_node **link, | |
1203 | struct list_head *head) | |
1204 | { | |
1205 | __link_va(va, root, parent, link, head, false); | |
1206 | } | |
1207 | ||
1208 | static __always_inline void | |
1209 | link_va_augment(struct vmap_area *va, struct rb_root *root, | |
1210 | struct rb_node *parent, struct rb_node **link, | |
1211 | struct list_head *head) | |
1212 | { | |
1213 | __link_va(va, root, parent, link, head, true); | |
1214 | } | |
1215 | ||
1216 | static __always_inline void | |
1217 | __unlink_va(struct vmap_area *va, struct rb_root *root, bool augment) | |
1218 | { | |
1219 | if (WARN_ON(RB_EMPTY_NODE(&va->rb_node))) | |
1220 | return; | |
1221 | ||
1222 | if (augment) | |
1223 | rb_erase_augmented(&va->rb_node, | |
1224 | root, &free_vmap_area_rb_augment_cb); | |
1225 | else | |
1226 | rb_erase(&va->rb_node, root); | |
1227 | ||
1228 | list_del_init(&va->list); | |
1229 | RB_CLEAR_NODE(&va->rb_node); | |
1230 | } | |
1231 | ||
1232 | static __always_inline void | |
1233 | unlink_va(struct vmap_area *va, struct rb_root *root) | |
1234 | { | |
1235 | __unlink_va(va, root, false); | |
1236 | } | |
1237 | ||
1238 | static __always_inline void | |
1239 | unlink_va_augment(struct vmap_area *va, struct rb_root *root) | |
1240 | { | |
1241 | __unlink_va(va, root, true); | |
1242 | } | |
1243 | ||
1244 | #if DEBUG_AUGMENT_PROPAGATE_CHECK | |
1245 | /* | |
1246 | * Gets called when remove the node and rotate. | |
1247 | */ | |
1248 | static __always_inline unsigned long | |
1249 | compute_subtree_max_size(struct vmap_area *va) | |
1250 | { | |
1251 | return max3(va_size(va), | |
1252 | get_subtree_max_size(va->rb_node.rb_left), | |
1253 | get_subtree_max_size(va->rb_node.rb_right)); | |
1254 | } | |
1255 | ||
1256 | static void | |
1257 | augment_tree_propagate_check(void) | |
1258 | { | |
1259 | struct vmap_area *va; | |
1260 | unsigned long computed_size; | |
1261 | ||
1262 | list_for_each_entry(va, &free_vmap_area_list, list) { | |
1263 | computed_size = compute_subtree_max_size(va); | |
1264 | if (computed_size != va->subtree_max_size) | |
1265 | pr_emerg("tree is corrupted: %lu, %lu\n", | |
1266 | va_size(va), va->subtree_max_size); | |
1267 | } | |
1268 | } | |
1269 | #endif | |
1270 | ||
1271 | /* | |
1272 | * This function populates subtree_max_size from bottom to upper | |
1273 | * levels starting from VA point. The propagation must be done | |
1274 | * when VA size is modified by changing its va_start/va_end. Or | |
1275 | * in case of newly inserting of VA to the tree. | |
1276 | * | |
1277 | * It means that __augment_tree_propagate_from() must be called: | |
1278 | * - After VA has been inserted to the tree(free path); | |
1279 | * - After VA has been shrunk(allocation path); | |
1280 | * - After VA has been increased(merging path). | |
1281 | * | |
1282 | * Please note that, it does not mean that upper parent nodes | |
1283 | * and their subtree_max_size are recalculated all the time up | |
1284 | * to the root node. | |
1285 | * | |
1286 | * 4--8 | |
1287 | * /\ | |
1288 | * / \ | |
1289 | * / \ | |
1290 | * 2--2 8--8 | |
1291 | * | |
1292 | * For example if we modify the node 4, shrinking it to 2, then | |
1293 | * no any modification is required. If we shrink the node 2 to 1 | |
1294 | * its subtree_max_size is updated only, and set to 1. If we shrink | |
1295 | * the node 8 to 6, then its subtree_max_size is set to 6 and parent | |
1296 | * node becomes 4--6. | |
1297 | */ | |
1298 | static __always_inline void | |
1299 | augment_tree_propagate_from(struct vmap_area *va) | |
1300 | { | |
1301 | /* | |
1302 | * Populate the tree from bottom towards the root until | |
1303 | * the calculated maximum available size of checked node | |
1304 | * is equal to its current one. | |
1305 | */ | |
1306 | free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL); | |
1307 | ||
1308 | #if DEBUG_AUGMENT_PROPAGATE_CHECK | |
1309 | augment_tree_propagate_check(); | |
1310 | #endif | |
1311 | } | |
1312 | ||
1313 | static void | |
1314 | insert_vmap_area(struct vmap_area *va, | |
1315 | struct rb_root *root, struct list_head *head) | |
1316 | { | |
1317 | struct rb_node **link; | |
1318 | struct rb_node *parent; | |
1319 | ||
1320 | link = find_va_links(va, root, NULL, &parent); | |
1321 | if (link) | |
1322 | link_va(va, root, parent, link, head); | |
1323 | } | |
1324 | ||
1325 | static void | |
1326 | insert_vmap_area_augment(struct vmap_area *va, | |
1327 | struct rb_node *from, struct rb_root *root, | |
1328 | struct list_head *head) | |
1329 | { | |
1330 | struct rb_node **link; | |
1331 | struct rb_node *parent; | |
1332 | ||
1333 | if (from) | |
1334 | link = find_va_links(va, NULL, from, &parent); | |
1335 | else | |
1336 | link = find_va_links(va, root, NULL, &parent); | |
1337 | ||
1338 | if (link) { | |
1339 | link_va_augment(va, root, parent, link, head); | |
1340 | augment_tree_propagate_from(va); | |
1341 | } | |
1342 | } | |
1343 | ||
1344 | /* | |
1345 | * Merge de-allocated chunk of VA memory with previous | |
1346 | * and next free blocks. If coalesce is not done a new | |
1347 | * free area is inserted. If VA has been merged, it is | |
1348 | * freed. | |
1349 | * | |
1350 | * Please note, it can return NULL in case of overlap | |
1351 | * ranges, followed by WARN() report. Despite it is a | |
1352 | * buggy behaviour, a system can be alive and keep | |
1353 | * ongoing. | |
1354 | */ | |
1355 | static __always_inline struct vmap_area * | |
1356 | __merge_or_add_vmap_area(struct vmap_area *va, | |
1357 | struct rb_root *root, struct list_head *head, bool augment) | |
1358 | { | |
1359 | struct vmap_area *sibling; | |
1360 | struct list_head *next; | |
1361 | struct rb_node **link; | |
1362 | struct rb_node *parent; | |
1363 | bool merged = false; | |
1364 | ||
1365 | /* | |
1366 | * Find a place in the tree where VA potentially will be | |
1367 | * inserted, unless it is merged with its sibling/siblings. | |
1368 | */ | |
1369 | link = find_va_links(va, root, NULL, &parent); | |
1370 | if (!link) | |
1371 | return NULL; | |
1372 | ||
1373 | /* | |
1374 | * Get next node of VA to check if merging can be done. | |
1375 | */ | |
1376 | next = get_va_next_sibling(parent, link); | |
1377 | if (unlikely(next == NULL)) | |
1378 | goto insert; | |
1379 | ||
1380 | /* | |
1381 | * start end | |
1382 | * | | | |
1383 | * |<------VA------>|<-----Next----->| | |
1384 | * | | | |
1385 | * start end | |
1386 | */ | |
1387 | if (next != head) { | |
1388 | sibling = list_entry(next, struct vmap_area, list); | |
1389 | if (sibling->va_start == va->va_end) { | |
1390 | sibling->va_start = va->va_start; | |
1391 | ||
1392 | /* Free vmap_area object. */ | |
1393 | kmem_cache_free(vmap_area_cachep, va); | |
1394 | ||
1395 | /* Point to the new merged area. */ | |
1396 | va = sibling; | |
1397 | merged = true; | |
1398 | } | |
1399 | } | |
1400 | ||
1401 | /* | |
1402 | * start end | |
1403 | * | | | |
1404 | * |<-----Prev----->|<------VA------>| | |
1405 | * | | | |
1406 | * start end | |
1407 | */ | |
1408 | if (next->prev != head) { | |
1409 | sibling = list_entry(next->prev, struct vmap_area, list); | |
1410 | if (sibling->va_end == va->va_start) { | |
1411 | /* | |
1412 | * If both neighbors are coalesced, it is important | |
1413 | * to unlink the "next" node first, followed by merging | |
1414 | * with "previous" one. Otherwise the tree might not be | |
1415 | * fully populated if a sibling's augmented value is | |
1416 | * "normalized" because of rotation operations. | |
1417 | */ | |
1418 | if (merged) | |
1419 | __unlink_va(va, root, augment); | |
1420 | ||
1421 | sibling->va_end = va->va_end; | |
1422 | ||
1423 | /* Free vmap_area object. */ | |
1424 | kmem_cache_free(vmap_area_cachep, va); | |
1425 | ||
1426 | /* Point to the new merged area. */ | |
1427 | va = sibling; | |
1428 | merged = true; | |
1429 | } | |
1430 | } | |
1431 | ||
1432 | insert: | |
1433 | if (!merged) | |
1434 | __link_va(va, root, parent, link, head, augment); | |
1435 | ||
1436 | return va; | |
1437 | } | |
1438 | ||
1439 | static __always_inline struct vmap_area * | |
1440 | merge_or_add_vmap_area(struct vmap_area *va, | |
1441 | struct rb_root *root, struct list_head *head) | |
1442 | { | |
1443 | return __merge_or_add_vmap_area(va, root, head, false); | |
1444 | } | |
1445 | ||
1446 | static __always_inline struct vmap_area * | |
1447 | merge_or_add_vmap_area_augment(struct vmap_area *va, | |
1448 | struct rb_root *root, struct list_head *head) | |
1449 | { | |
1450 | va = __merge_or_add_vmap_area(va, root, head, true); | |
1451 | if (va) | |
1452 | augment_tree_propagate_from(va); | |
1453 | ||
1454 | return va; | |
1455 | } | |
1456 | ||
1457 | static __always_inline bool | |
1458 | is_within_this_va(struct vmap_area *va, unsigned long size, | |
1459 | unsigned long align, unsigned long vstart) | |
1460 | { | |
1461 | unsigned long nva_start_addr; | |
1462 | ||
1463 | if (va->va_start > vstart) | |
1464 | nva_start_addr = ALIGN(va->va_start, align); | |
1465 | else | |
1466 | nva_start_addr = ALIGN(vstart, align); | |
1467 | ||
1468 | /* Can be overflowed due to big size or alignment. */ | |
1469 | if (nva_start_addr + size < nva_start_addr || | |
1470 | nva_start_addr < vstart) | |
1471 | return false; | |
1472 | ||
1473 | return (nva_start_addr + size <= va->va_end); | |
1474 | } | |
1475 | ||
1476 | /* | |
1477 | * Find the first free block(lowest start address) in the tree, | |
1478 | * that will accomplish the request corresponding to passing | |
1479 | * parameters. Please note, with an alignment bigger than PAGE_SIZE, | |
1480 | * a search length is adjusted to account for worst case alignment | |
1481 | * overhead. | |
1482 | */ | |
1483 | static __always_inline struct vmap_area * | |
1484 | find_vmap_lowest_match(struct rb_root *root, unsigned long size, | |
1485 | unsigned long align, unsigned long vstart, bool adjust_search_size) | |
1486 | { | |
1487 | struct vmap_area *va; | |
1488 | struct rb_node *node; | |
1489 | unsigned long length; | |
1490 | ||
1491 | /* Start from the root. */ | |
1492 | node = root->rb_node; | |
1493 | ||
1494 | /* Adjust the search size for alignment overhead. */ | |
1495 | length = adjust_search_size ? size + align - 1 : size; | |
1496 | ||
1497 | while (node) { | |
1498 | va = rb_entry(node, struct vmap_area, rb_node); | |
1499 | ||
1500 | if (get_subtree_max_size(node->rb_left) >= length && | |
1501 | vstart < va->va_start) { | |
1502 | node = node->rb_left; | |
1503 | } else { | |
1504 | if (is_within_this_va(va, size, align, vstart)) | |
1505 | return va; | |
1506 | ||
1507 | /* | |
1508 | * Does not make sense to go deeper towards the right | |
1509 | * sub-tree if it does not have a free block that is | |
1510 | * equal or bigger to the requested search length. | |
1511 | */ | |
1512 | if (get_subtree_max_size(node->rb_right) >= length) { | |
1513 | node = node->rb_right; | |
1514 | continue; | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * OK. We roll back and find the first right sub-tree, | |
1519 | * that will satisfy the search criteria. It can happen | |
1520 | * due to "vstart" restriction or an alignment overhead | |
1521 | * that is bigger then PAGE_SIZE. | |
1522 | */ | |
1523 | while ((node = rb_parent(node))) { | |
1524 | va = rb_entry(node, struct vmap_area, rb_node); | |
1525 | if (is_within_this_va(va, size, align, vstart)) | |
1526 | return va; | |
1527 | ||
1528 | if (get_subtree_max_size(node->rb_right) >= length && | |
1529 | vstart <= va->va_start) { | |
1530 | /* | |
1531 | * Shift the vstart forward. Please note, we update it with | |
1532 | * parent's start address adding "1" because we do not want | |
1533 | * to enter same sub-tree after it has already been checked | |
1534 | * and no suitable free block found there. | |
1535 | */ | |
1536 | vstart = va->va_start + 1; | |
1537 | node = node->rb_right; | |
1538 | break; | |
1539 | } | |
1540 | } | |
1541 | } | |
1542 | } | |
1543 | ||
1544 | return NULL; | |
1545 | } | |
1546 | ||
1547 | #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK | |
1548 | #include <linux/random.h> | |
1549 | ||
1550 | static struct vmap_area * | |
1551 | find_vmap_lowest_linear_match(struct list_head *head, unsigned long size, | |
1552 | unsigned long align, unsigned long vstart) | |
1553 | { | |
1554 | struct vmap_area *va; | |
1555 | ||
1556 | list_for_each_entry(va, head, list) { | |
1557 | if (!is_within_this_va(va, size, align, vstart)) | |
1558 | continue; | |
1559 | ||
1560 | return va; | |
1561 | } | |
1562 | ||
1563 | return NULL; | |
1564 | } | |
1565 | ||
1566 | static void | |
1567 | find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head, | |
1568 | unsigned long size, unsigned long align) | |
1569 | { | |
1570 | struct vmap_area *va_1, *va_2; | |
1571 | unsigned long vstart; | |
1572 | unsigned int rnd; | |
1573 | ||
1574 | get_random_bytes(&rnd, sizeof(rnd)); | |
1575 | vstart = VMALLOC_START + rnd; | |
1576 | ||
1577 | va_1 = find_vmap_lowest_match(root, size, align, vstart, false); | |
1578 | va_2 = find_vmap_lowest_linear_match(head, size, align, vstart); | |
1579 | ||
1580 | if (va_1 != va_2) | |
1581 | pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n", | |
1582 | va_1, va_2, vstart); | |
1583 | } | |
1584 | #endif | |
1585 | ||
1586 | enum fit_type { | |
1587 | NOTHING_FIT = 0, | |
1588 | FL_FIT_TYPE = 1, /* full fit */ | |
1589 | LE_FIT_TYPE = 2, /* left edge fit */ | |
1590 | RE_FIT_TYPE = 3, /* right edge fit */ | |
1591 | NE_FIT_TYPE = 4 /* no edge fit */ | |
1592 | }; | |
1593 | ||
1594 | static __always_inline enum fit_type | |
1595 | classify_va_fit_type(struct vmap_area *va, | |
1596 | unsigned long nva_start_addr, unsigned long size) | |
1597 | { | |
1598 | enum fit_type type; | |
1599 | ||
1600 | /* Check if it is within VA. */ | |
1601 | if (nva_start_addr < va->va_start || | |
1602 | nva_start_addr + size > va->va_end) | |
1603 | return NOTHING_FIT; | |
1604 | ||
1605 | /* Now classify. */ | |
1606 | if (va->va_start == nva_start_addr) { | |
1607 | if (va->va_end == nva_start_addr + size) | |
1608 | type = FL_FIT_TYPE; | |
1609 | else | |
1610 | type = LE_FIT_TYPE; | |
1611 | } else if (va->va_end == nva_start_addr + size) { | |
1612 | type = RE_FIT_TYPE; | |
1613 | } else { | |
1614 | type = NE_FIT_TYPE; | |
1615 | } | |
1616 | ||
1617 | return type; | |
1618 | } | |
1619 | ||
1620 | static __always_inline int | |
1621 | va_clip(struct rb_root *root, struct list_head *head, | |
1622 | struct vmap_area *va, unsigned long nva_start_addr, | |
1623 | unsigned long size) | |
1624 | { | |
1625 | struct vmap_area *lva = NULL; | |
1626 | enum fit_type type = classify_va_fit_type(va, nva_start_addr, size); | |
1627 | ||
1628 | if (type == FL_FIT_TYPE) { | |
1629 | /* | |
1630 | * No need to split VA, it fully fits. | |
1631 | * | |
1632 | * | | | |
1633 | * V NVA V | |
1634 | * |---------------| | |
1635 | */ | |
1636 | unlink_va_augment(va, root); | |
1637 | kmem_cache_free(vmap_area_cachep, va); | |
1638 | } else if (type == LE_FIT_TYPE) { | |
1639 | /* | |
1640 | * Split left edge of fit VA. | |
1641 | * | |
1642 | * | | | |
1643 | * V NVA V R | |
1644 | * |-------|-------| | |
1645 | */ | |
1646 | va->va_start += size; | |
1647 | } else if (type == RE_FIT_TYPE) { | |
1648 | /* | |
1649 | * Split right edge of fit VA. | |
1650 | * | |
1651 | * | | | |
1652 | * L V NVA V | |
1653 | * |-------|-------| | |
1654 | */ | |
1655 | va->va_end = nva_start_addr; | |
1656 | } else if (type == NE_FIT_TYPE) { | |
1657 | /* | |
1658 | * Split no edge of fit VA. | |
1659 | * | |
1660 | * | | | |
1661 | * L V NVA V R | |
1662 | * |---|-------|---| | |
1663 | */ | |
1664 | lva = __this_cpu_xchg(ne_fit_preload_node, NULL); | |
1665 | if (unlikely(!lva)) { | |
1666 | /* | |
1667 | * For percpu allocator we do not do any pre-allocation | |
1668 | * and leave it as it is. The reason is it most likely | |
1669 | * never ends up with NE_FIT_TYPE splitting. In case of | |
1670 | * percpu allocations offsets and sizes are aligned to | |
1671 | * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE | |
1672 | * are its main fitting cases. | |
1673 | * | |
1674 | * There are a few exceptions though, as an example it is | |
1675 | * a first allocation (early boot up) when we have "one" | |
1676 | * big free space that has to be split. | |
1677 | * | |
1678 | * Also we can hit this path in case of regular "vmap" | |
1679 | * allocations, if "this" current CPU was not preloaded. | |
1680 | * See the comment in alloc_vmap_area() why. If so, then | |
1681 | * GFP_NOWAIT is used instead to get an extra object for | |
1682 | * split purpose. That is rare and most time does not | |
1683 | * occur. | |
1684 | * | |
1685 | * What happens if an allocation gets failed. Basically, | |
1686 | * an "overflow" path is triggered to purge lazily freed | |
1687 | * areas to free some memory, then, the "retry" path is | |
1688 | * triggered to repeat one more time. See more details | |
1689 | * in alloc_vmap_area() function. | |
1690 | */ | |
1691 | lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT); | |
1692 | if (!lva) | |
1693 | return -1; | |
1694 | } | |
1695 | ||
1696 | /* | |
1697 | * Build the remainder. | |
1698 | */ | |
1699 | lva->va_start = va->va_start; | |
1700 | lva->va_end = nva_start_addr; | |
1701 | ||
1702 | /* | |
1703 | * Shrink this VA to remaining size. | |
1704 | */ | |
1705 | va->va_start = nva_start_addr + size; | |
1706 | } else { | |
1707 | return -1; | |
1708 | } | |
1709 | ||
1710 | if (type != FL_FIT_TYPE) { | |
1711 | augment_tree_propagate_from(va); | |
1712 | ||
1713 | if (lva) /* type == NE_FIT_TYPE */ | |
1714 | insert_vmap_area_augment(lva, &va->rb_node, root, head); | |
1715 | } | |
1716 | ||
1717 | return 0; | |
1718 | } | |
1719 | ||
1720 | static unsigned long | |
1721 | va_alloc(struct vmap_area *va, | |
1722 | struct rb_root *root, struct list_head *head, | |
1723 | unsigned long size, unsigned long align, | |
1724 | unsigned long vstart, unsigned long vend) | |
1725 | { | |
1726 | unsigned long nva_start_addr; | |
1727 | int ret; | |
1728 | ||
1729 | if (va->va_start > vstart) | |
1730 | nva_start_addr = ALIGN(va->va_start, align); | |
1731 | else | |
1732 | nva_start_addr = ALIGN(vstart, align); | |
1733 | ||
1734 | /* Check the "vend" restriction. */ | |
1735 | if (nva_start_addr + size > vend) | |
1736 | return vend; | |
1737 | ||
1738 | /* Update the free vmap_area. */ | |
1739 | ret = va_clip(root, head, va, nva_start_addr, size); | |
1740 | if (WARN_ON_ONCE(ret)) | |
1741 | return vend; | |
1742 | ||
1743 | return nva_start_addr; | |
1744 | } | |
1745 | ||
1746 | /* | |
1747 | * Returns a start address of the newly allocated area, if success. | |
1748 | * Otherwise a vend is returned that indicates failure. | |
1749 | */ | |
1750 | static __always_inline unsigned long | |
1751 | __alloc_vmap_area(struct rb_root *root, struct list_head *head, | |
1752 | unsigned long size, unsigned long align, | |
1753 | unsigned long vstart, unsigned long vend) | |
1754 | { | |
1755 | bool adjust_search_size = true; | |
1756 | unsigned long nva_start_addr; | |
1757 | struct vmap_area *va; | |
1758 | ||
1759 | /* | |
1760 | * Do not adjust when: | |
1761 | * a) align <= PAGE_SIZE, because it does not make any sense. | |
1762 | * All blocks(their start addresses) are at least PAGE_SIZE | |
1763 | * aligned anyway; | |
1764 | * b) a short range where a requested size corresponds to exactly | |
1765 | * specified [vstart:vend] interval and an alignment > PAGE_SIZE. | |
1766 | * With adjusted search length an allocation would not succeed. | |
1767 | */ | |
1768 | if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size)) | |
1769 | adjust_search_size = false; | |
1770 | ||
1771 | va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size); | |
1772 | if (unlikely(!va)) | |
1773 | return vend; | |
1774 | ||
1775 | nva_start_addr = va_alloc(va, root, head, size, align, vstart, vend); | |
1776 | if (nva_start_addr == vend) | |
1777 | return vend; | |
1778 | ||
1779 | #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK | |
1780 | find_vmap_lowest_match_check(root, head, size, align); | |
1781 | #endif | |
1782 | ||
1783 | return nva_start_addr; | |
1784 | } | |
1785 | ||
1786 | /* | |
1787 | * Free a region of KVA allocated by alloc_vmap_area | |
1788 | */ | |
1789 | static void free_vmap_area(struct vmap_area *va) | |
1790 | { | |
1791 | struct vmap_node *vn = addr_to_node(va->va_start); | |
1792 | ||
1793 | /* | |
1794 | * Remove from the busy tree/list. | |
1795 | */ | |
1796 | spin_lock(&vn->busy.lock); | |
1797 | unlink_va(va, &vn->busy.root); | |
1798 | spin_unlock(&vn->busy.lock); | |
1799 | ||
1800 | /* | |
1801 | * Insert/Merge it back to the free tree/list. | |
1802 | */ | |
1803 | spin_lock(&free_vmap_area_lock); | |
1804 | merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list); | |
1805 | spin_unlock(&free_vmap_area_lock); | |
1806 | } | |
1807 | ||
1808 | static inline void | |
1809 | preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node) | |
1810 | { | |
1811 | struct vmap_area *va = NULL; | |
1812 | ||
1813 | /* | |
1814 | * Preload this CPU with one extra vmap_area object. It is used | |
1815 | * when fit type of free area is NE_FIT_TYPE. It guarantees that | |
1816 | * a CPU that does an allocation is preloaded. | |
1817 | * | |
1818 | * We do it in non-atomic context, thus it allows us to use more | |
1819 | * permissive allocation masks to be more stable under low memory | |
1820 | * condition and high memory pressure. | |
1821 | */ | |
1822 | if (!this_cpu_read(ne_fit_preload_node)) | |
1823 | va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); | |
1824 | ||
1825 | spin_lock(lock); | |
1826 | ||
1827 | if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va)) | |
1828 | kmem_cache_free(vmap_area_cachep, va); | |
1829 | } | |
1830 | ||
1831 | static struct vmap_pool * | |
1832 | size_to_va_pool(struct vmap_node *vn, unsigned long size) | |
1833 | { | |
1834 | unsigned int idx = (size - 1) / PAGE_SIZE; | |
1835 | ||
1836 | if (idx < MAX_VA_SIZE_PAGES) | |
1837 | return &vn->pool[idx]; | |
1838 | ||
1839 | return NULL; | |
1840 | } | |
1841 | ||
1842 | static bool | |
1843 | node_pool_add_va(struct vmap_node *n, struct vmap_area *va) | |
1844 | { | |
1845 | struct vmap_pool *vp; | |
1846 | ||
1847 | vp = size_to_va_pool(n, va_size(va)); | |
1848 | if (!vp) | |
1849 | return false; | |
1850 | ||
1851 | spin_lock(&n->pool_lock); | |
1852 | list_add(&va->list, &vp->head); | |
1853 | WRITE_ONCE(vp->len, vp->len + 1); | |
1854 | spin_unlock(&n->pool_lock); | |
1855 | ||
1856 | return true; | |
1857 | } | |
1858 | ||
1859 | static struct vmap_area * | |
1860 | node_pool_del_va(struct vmap_node *vn, unsigned long size, | |
1861 | unsigned long align, unsigned long vstart, | |
1862 | unsigned long vend) | |
1863 | { | |
1864 | struct vmap_area *va = NULL; | |
1865 | struct vmap_pool *vp; | |
1866 | int err = 0; | |
1867 | ||
1868 | vp = size_to_va_pool(vn, size); | |
1869 | if (!vp || list_empty(&vp->head)) | |
1870 | return NULL; | |
1871 | ||
1872 | spin_lock(&vn->pool_lock); | |
1873 | if (!list_empty(&vp->head)) { | |
1874 | va = list_first_entry(&vp->head, struct vmap_area, list); | |
1875 | ||
1876 | if (IS_ALIGNED(va->va_start, align)) { | |
1877 | /* | |
1878 | * Do some sanity check and emit a warning | |
1879 | * if one of below checks detects an error. | |
1880 | */ | |
1881 | err |= (va_size(va) != size); | |
1882 | err |= (va->va_start < vstart); | |
1883 | err |= (va->va_end > vend); | |
1884 | ||
1885 | if (!WARN_ON_ONCE(err)) { | |
1886 | list_del_init(&va->list); | |
1887 | WRITE_ONCE(vp->len, vp->len - 1); | |
1888 | } else { | |
1889 | va = NULL; | |
1890 | } | |
1891 | } else { | |
1892 | list_move_tail(&va->list, &vp->head); | |
1893 | va = NULL; | |
1894 | } | |
1895 | } | |
1896 | spin_unlock(&vn->pool_lock); | |
1897 | ||
1898 | return va; | |
1899 | } | |
1900 | ||
1901 | static struct vmap_area * | |
1902 | node_alloc(unsigned long size, unsigned long align, | |
1903 | unsigned long vstart, unsigned long vend, | |
1904 | unsigned long *addr, unsigned int *vn_id) | |
1905 | { | |
1906 | struct vmap_area *va; | |
1907 | ||
1908 | *vn_id = 0; | |
1909 | *addr = vend; | |
1910 | ||
1911 | /* | |
1912 | * Fallback to a global heap if not vmalloc or there | |
1913 | * is only one node. | |
1914 | */ | |
1915 | if (vstart != VMALLOC_START || vend != VMALLOC_END || | |
1916 | nr_vmap_nodes == 1) | |
1917 | return NULL; | |
1918 | ||
1919 | *vn_id = raw_smp_processor_id() % nr_vmap_nodes; | |
1920 | va = node_pool_del_va(id_to_node(*vn_id), size, align, vstart, vend); | |
1921 | *vn_id = encode_vn_id(*vn_id); | |
1922 | ||
1923 | if (va) | |
1924 | *addr = va->va_start; | |
1925 | ||
1926 | return va; | |
1927 | } | |
1928 | ||
1929 | /* | |
1930 | * Allocate a region of KVA of the specified size and alignment, within the | |
1931 | * vstart and vend. | |
1932 | */ | |
1933 | static struct vmap_area *alloc_vmap_area(unsigned long size, | |
1934 | unsigned long align, | |
1935 | unsigned long vstart, unsigned long vend, | |
1936 | int node, gfp_t gfp_mask, | |
1937 | unsigned long va_flags) | |
1938 | { | |
1939 | struct vmap_node *vn; | |
1940 | struct vmap_area *va; | |
1941 | unsigned long freed; | |
1942 | unsigned long addr; | |
1943 | unsigned int vn_id; | |
1944 | int purged = 0; | |
1945 | int ret; | |
1946 | ||
1947 | if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align))) | |
1948 | return ERR_PTR(-EINVAL); | |
1949 | ||
1950 | if (unlikely(!vmap_initialized)) | |
1951 | return ERR_PTR(-EBUSY); | |
1952 | ||
1953 | might_sleep(); | |
1954 | ||
1955 | /* | |
1956 | * If a VA is obtained from a global heap(if it fails here) | |
1957 | * it is anyway marked with this "vn_id" so it is returned | |
1958 | * to this pool's node later. Such way gives a possibility | |
1959 | * to populate pools based on users demand. | |
1960 | * | |
1961 | * On success a ready to go VA is returned. | |
1962 | */ | |
1963 | va = node_alloc(size, align, vstart, vend, &addr, &vn_id); | |
1964 | if (!va) { | |
1965 | gfp_mask = gfp_mask & GFP_RECLAIM_MASK; | |
1966 | ||
1967 | va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); | |
1968 | if (unlikely(!va)) | |
1969 | return ERR_PTR(-ENOMEM); | |
1970 | ||
1971 | /* | |
1972 | * Only scan the relevant parts containing pointers to other objects | |
1973 | * to avoid false negatives. | |
1974 | */ | |
1975 | kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask); | |
1976 | } | |
1977 | ||
1978 | retry: | |
1979 | if (addr == vend) { | |
1980 | preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node); | |
1981 | addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list, | |
1982 | size, align, vstart, vend); | |
1983 | spin_unlock(&free_vmap_area_lock); | |
1984 | } | |
1985 | ||
1986 | trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend); | |
1987 | ||
1988 | /* | |
1989 | * If an allocation fails, the "vend" address is | |
1990 | * returned. Therefore trigger the overflow path. | |
1991 | */ | |
1992 | if (unlikely(addr == vend)) | |
1993 | goto overflow; | |
1994 | ||
1995 | va->va_start = addr; | |
1996 | va->va_end = addr + size; | |
1997 | va->vm = NULL; | |
1998 | va->flags = (va_flags | vn_id); | |
1999 | ||
2000 | vn = addr_to_node(va->va_start); | |
2001 | ||
2002 | spin_lock(&vn->busy.lock); | |
2003 | insert_vmap_area(va, &vn->busy.root, &vn->busy.head); | |
2004 | spin_unlock(&vn->busy.lock); | |
2005 | ||
2006 | BUG_ON(!IS_ALIGNED(va->va_start, align)); | |
2007 | BUG_ON(va->va_start < vstart); | |
2008 | BUG_ON(va->va_end > vend); | |
2009 | ||
2010 | ret = kasan_populate_vmalloc(addr, size); | |
2011 | if (ret) { | |
2012 | free_vmap_area(va); | |
2013 | return ERR_PTR(ret); | |
2014 | } | |
2015 | ||
2016 | return va; | |
2017 | ||
2018 | overflow: | |
2019 | if (!purged) { | |
2020 | reclaim_and_purge_vmap_areas(); | |
2021 | purged = 1; | |
2022 | goto retry; | |
2023 | } | |
2024 | ||
2025 | freed = 0; | |
2026 | blocking_notifier_call_chain(&vmap_notify_list, 0, &freed); | |
2027 | ||
2028 | if (freed > 0) { | |
2029 | purged = 0; | |
2030 | goto retry; | |
2031 | } | |
2032 | ||
2033 | if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) | |
2034 | pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n", | |
2035 | size); | |
2036 | ||
2037 | kmem_cache_free(vmap_area_cachep, va); | |
2038 | return ERR_PTR(-EBUSY); | |
2039 | } | |
2040 | ||
2041 | int register_vmap_purge_notifier(struct notifier_block *nb) | |
2042 | { | |
2043 | return blocking_notifier_chain_register(&vmap_notify_list, nb); | |
2044 | } | |
2045 | EXPORT_SYMBOL_GPL(register_vmap_purge_notifier); | |
2046 | ||
2047 | int unregister_vmap_purge_notifier(struct notifier_block *nb) | |
2048 | { | |
2049 | return blocking_notifier_chain_unregister(&vmap_notify_list, nb); | |
2050 | } | |
2051 | EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier); | |
2052 | ||
2053 | /* | |
2054 | * lazy_max_pages is the maximum amount of virtual address space we gather up | |
2055 | * before attempting to purge with a TLB flush. | |
2056 | * | |
2057 | * There is a tradeoff here: a larger number will cover more kernel page tables | |
2058 | * and take slightly longer to purge, but it will linearly reduce the number of | |
2059 | * global TLB flushes that must be performed. It would seem natural to scale | |
2060 | * this number up linearly with the number of CPUs (because vmapping activity | |
2061 | * could also scale linearly with the number of CPUs), however it is likely | |
2062 | * that in practice, workloads might be constrained in other ways that mean | |
2063 | * vmap activity will not scale linearly with CPUs. Also, I want to be | |
2064 | * conservative and not introduce a big latency on huge systems, so go with | |
2065 | * a less aggressive log scale. It will still be an improvement over the old | |
2066 | * code, and it will be simple to change the scale factor if we find that it | |
2067 | * becomes a problem on bigger systems. | |
2068 | */ | |
2069 | static unsigned long lazy_max_pages(void) | |
2070 | { | |
2071 | unsigned int log; | |
2072 | ||
2073 | log = fls(num_online_cpus()); | |
2074 | ||
2075 | return log * (32UL * 1024 * 1024 / PAGE_SIZE); | |
2076 | } | |
2077 | ||
2078 | static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0); | |
2079 | ||
2080 | /* | |
2081 | * Serialize vmap purging. There is no actual critical section protected | |
2082 | * by this lock, but we want to avoid concurrent calls for performance | |
2083 | * reasons and to make the pcpu_get_vm_areas more deterministic. | |
2084 | */ | |
2085 | static DEFINE_MUTEX(vmap_purge_lock); | |
2086 | ||
2087 | /* for per-CPU blocks */ | |
2088 | static void purge_fragmented_blocks_allcpus(void); | |
2089 | static cpumask_t purge_nodes; | |
2090 | ||
2091 | static void | |
2092 | reclaim_list_global(struct list_head *head) | |
2093 | { | |
2094 | struct vmap_area *va, *n; | |
2095 | ||
2096 | if (list_empty(head)) | |
2097 | return; | |
2098 | ||
2099 | spin_lock(&free_vmap_area_lock); | |
2100 | list_for_each_entry_safe(va, n, head, list) | |
2101 | merge_or_add_vmap_area_augment(va, | |
2102 | &free_vmap_area_root, &free_vmap_area_list); | |
2103 | spin_unlock(&free_vmap_area_lock); | |
2104 | } | |
2105 | ||
2106 | static void | |
2107 | decay_va_pool_node(struct vmap_node *vn, bool full_decay) | |
2108 | { | |
2109 | struct vmap_area *va, *nva; | |
2110 | struct list_head decay_list; | |
2111 | struct rb_root decay_root; | |
2112 | unsigned long n_decay; | |
2113 | int i; | |
2114 | ||
2115 | decay_root = RB_ROOT; | |
2116 | INIT_LIST_HEAD(&decay_list); | |
2117 | ||
2118 | for (i = 0; i < MAX_VA_SIZE_PAGES; i++) { | |
2119 | struct list_head tmp_list; | |
2120 | ||
2121 | if (list_empty(&vn->pool[i].head)) | |
2122 | continue; | |
2123 | ||
2124 | INIT_LIST_HEAD(&tmp_list); | |
2125 | ||
2126 | /* Detach the pool, so no-one can access it. */ | |
2127 | spin_lock(&vn->pool_lock); | |
2128 | list_replace_init(&vn->pool[i].head, &tmp_list); | |
2129 | spin_unlock(&vn->pool_lock); | |
2130 | ||
2131 | if (full_decay) | |
2132 | WRITE_ONCE(vn->pool[i].len, 0); | |
2133 | ||
2134 | /* Decay a pool by ~25% out of left objects. */ | |
2135 | n_decay = vn->pool[i].len >> 2; | |
2136 | ||
2137 | list_for_each_entry_safe(va, nva, &tmp_list, list) { | |
2138 | list_del_init(&va->list); | |
2139 | merge_or_add_vmap_area(va, &decay_root, &decay_list); | |
2140 | ||
2141 | if (!full_decay) { | |
2142 | WRITE_ONCE(vn->pool[i].len, vn->pool[i].len - 1); | |
2143 | ||
2144 | if (!--n_decay) | |
2145 | break; | |
2146 | } | |
2147 | } | |
2148 | ||
2149 | /* | |
2150 | * Attach the pool back if it has been partly decayed. | |
2151 | * Please note, it is supposed that nobody(other contexts) | |
2152 | * can populate the pool therefore a simple list replace | |
2153 | * operation takes place here. | |
2154 | */ | |
2155 | if (!full_decay && !list_empty(&tmp_list)) { | |
2156 | spin_lock(&vn->pool_lock); | |
2157 | list_replace_init(&tmp_list, &vn->pool[i].head); | |
2158 | spin_unlock(&vn->pool_lock); | |
2159 | } | |
2160 | } | |
2161 | ||
2162 | reclaim_list_global(&decay_list); | |
2163 | } | |
2164 | ||
2165 | static void purge_vmap_node(struct work_struct *work) | |
2166 | { | |
2167 | struct vmap_node *vn = container_of(work, | |
2168 | struct vmap_node, purge_work); | |
2169 | struct vmap_area *va, *n_va; | |
2170 | LIST_HEAD(local_list); | |
2171 | ||
2172 | vn->nr_purged = 0; | |
2173 | ||
2174 | list_for_each_entry_safe(va, n_va, &vn->purge_list, list) { | |
2175 | unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT; | |
2176 | unsigned long orig_start = va->va_start; | |
2177 | unsigned long orig_end = va->va_end; | |
2178 | unsigned int vn_id = decode_vn_id(va->flags); | |
2179 | ||
2180 | list_del_init(&va->list); | |
2181 | ||
2182 | if (is_vmalloc_or_module_addr((void *)orig_start)) | |
2183 | kasan_release_vmalloc(orig_start, orig_end, | |
2184 | va->va_start, va->va_end); | |
2185 | ||
2186 | atomic_long_sub(nr, &vmap_lazy_nr); | |
2187 | vn->nr_purged++; | |
2188 | ||
2189 | if (is_vn_id_valid(vn_id) && !vn->skip_populate) | |
2190 | if (node_pool_add_va(vn, va)) | |
2191 | continue; | |
2192 | ||
2193 | /* Go back to global. */ | |
2194 | list_add(&va->list, &local_list); | |
2195 | } | |
2196 | ||
2197 | reclaim_list_global(&local_list); | |
2198 | } | |
2199 | ||
2200 | /* | |
2201 | * Purges all lazily-freed vmap areas. | |
2202 | */ | |
2203 | static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end, | |
2204 | bool full_pool_decay) | |
2205 | { | |
2206 | unsigned long nr_purged_areas = 0; | |
2207 | unsigned int nr_purge_helpers; | |
2208 | unsigned int nr_purge_nodes; | |
2209 | struct vmap_node *vn; | |
2210 | int i; | |
2211 | ||
2212 | lockdep_assert_held(&vmap_purge_lock); | |
2213 | ||
2214 | /* | |
2215 | * Use cpumask to mark which node has to be processed. | |
2216 | */ | |
2217 | purge_nodes = CPU_MASK_NONE; | |
2218 | ||
2219 | for (i = 0; i < nr_vmap_nodes; i++) { | |
2220 | vn = &vmap_nodes[i]; | |
2221 | ||
2222 | INIT_LIST_HEAD(&vn->purge_list); | |
2223 | vn->skip_populate = full_pool_decay; | |
2224 | decay_va_pool_node(vn, full_pool_decay); | |
2225 | ||
2226 | if (RB_EMPTY_ROOT(&vn->lazy.root)) | |
2227 | continue; | |
2228 | ||
2229 | spin_lock(&vn->lazy.lock); | |
2230 | WRITE_ONCE(vn->lazy.root.rb_node, NULL); | |
2231 | list_replace_init(&vn->lazy.head, &vn->purge_list); | |
2232 | spin_unlock(&vn->lazy.lock); | |
2233 | ||
2234 | start = min(start, list_first_entry(&vn->purge_list, | |
2235 | struct vmap_area, list)->va_start); | |
2236 | ||
2237 | end = max(end, list_last_entry(&vn->purge_list, | |
2238 | struct vmap_area, list)->va_end); | |
2239 | ||
2240 | cpumask_set_cpu(i, &purge_nodes); | |
2241 | } | |
2242 | ||
2243 | nr_purge_nodes = cpumask_weight(&purge_nodes); | |
2244 | if (nr_purge_nodes > 0) { | |
2245 | flush_tlb_kernel_range(start, end); | |
2246 | ||
2247 | /* One extra worker is per a lazy_max_pages() full set minus one. */ | |
2248 | nr_purge_helpers = atomic_long_read(&vmap_lazy_nr) / lazy_max_pages(); | |
2249 | nr_purge_helpers = clamp(nr_purge_helpers, 1U, nr_purge_nodes) - 1; | |
2250 | ||
2251 | for_each_cpu(i, &purge_nodes) { | |
2252 | vn = &vmap_nodes[i]; | |
2253 | ||
2254 | if (nr_purge_helpers > 0) { | |
2255 | INIT_WORK(&vn->purge_work, purge_vmap_node); | |
2256 | ||
2257 | if (cpumask_test_cpu(i, cpu_online_mask)) | |
2258 | schedule_work_on(i, &vn->purge_work); | |
2259 | else | |
2260 | schedule_work(&vn->purge_work); | |
2261 | ||
2262 | nr_purge_helpers--; | |
2263 | } else { | |
2264 | vn->purge_work.func = NULL; | |
2265 | purge_vmap_node(&vn->purge_work); | |
2266 | nr_purged_areas += vn->nr_purged; | |
2267 | } | |
2268 | } | |
2269 | ||
2270 | for_each_cpu(i, &purge_nodes) { | |
2271 | vn = &vmap_nodes[i]; | |
2272 | ||
2273 | if (vn->purge_work.func) { | |
2274 | flush_work(&vn->purge_work); | |
2275 | nr_purged_areas += vn->nr_purged; | |
2276 | } | |
2277 | } | |
2278 | } | |
2279 | ||
2280 | trace_purge_vmap_area_lazy(start, end, nr_purged_areas); | |
2281 | return nr_purged_areas > 0; | |
2282 | } | |
2283 | ||
2284 | /* | |
2285 | * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list. | |
2286 | */ | |
2287 | static void reclaim_and_purge_vmap_areas(void) | |
2288 | ||
2289 | { | |
2290 | mutex_lock(&vmap_purge_lock); | |
2291 | purge_fragmented_blocks_allcpus(); | |
2292 | __purge_vmap_area_lazy(ULONG_MAX, 0, true); | |
2293 | mutex_unlock(&vmap_purge_lock); | |
2294 | } | |
2295 | ||
2296 | static void drain_vmap_area_work(struct work_struct *work) | |
2297 | { | |
2298 | mutex_lock(&vmap_purge_lock); | |
2299 | __purge_vmap_area_lazy(ULONG_MAX, 0, false); | |
2300 | mutex_unlock(&vmap_purge_lock); | |
2301 | } | |
2302 | ||
2303 | /* | |
2304 | * Free a vmap area, caller ensuring that the area has been unmapped, | |
2305 | * unlinked and flush_cache_vunmap had been called for the correct | |
2306 | * range previously. | |
2307 | */ | |
2308 | static void free_vmap_area_noflush(struct vmap_area *va) | |
2309 | { | |
2310 | unsigned long nr_lazy_max = lazy_max_pages(); | |
2311 | unsigned long va_start = va->va_start; | |
2312 | unsigned int vn_id = decode_vn_id(va->flags); | |
2313 | struct vmap_node *vn; | |
2314 | unsigned long nr_lazy; | |
2315 | ||
2316 | if (WARN_ON_ONCE(!list_empty(&va->list))) | |
2317 | return; | |
2318 | ||
2319 | nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >> | |
2320 | PAGE_SHIFT, &vmap_lazy_nr); | |
2321 | ||
2322 | /* | |
2323 | * If it was request by a certain node we would like to | |
2324 | * return it to that node, i.e. its pool for later reuse. | |
2325 | */ | |
2326 | vn = is_vn_id_valid(vn_id) ? | |
2327 | id_to_node(vn_id):addr_to_node(va->va_start); | |
2328 | ||
2329 | spin_lock(&vn->lazy.lock); | |
2330 | insert_vmap_area(va, &vn->lazy.root, &vn->lazy.head); | |
2331 | spin_unlock(&vn->lazy.lock); | |
2332 | ||
2333 | trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max); | |
2334 | ||
2335 | /* After this point, we may free va at any time */ | |
2336 | if (unlikely(nr_lazy > nr_lazy_max)) | |
2337 | schedule_work(&drain_vmap_work); | |
2338 | } | |
2339 | ||
2340 | /* | |
2341 | * Free and unmap a vmap area | |
2342 | */ | |
2343 | static void free_unmap_vmap_area(struct vmap_area *va) | |
2344 | { | |
2345 | flush_cache_vunmap(va->va_start, va->va_end); | |
2346 | vunmap_range_noflush(va->va_start, va->va_end); | |
2347 | if (debug_pagealloc_enabled_static()) | |
2348 | flush_tlb_kernel_range(va->va_start, va->va_end); | |
2349 | ||
2350 | free_vmap_area_noflush(va); | |
2351 | } | |
2352 | ||
2353 | struct vmap_area *find_vmap_area(unsigned long addr) | |
2354 | { | |
2355 | struct vmap_node *vn; | |
2356 | struct vmap_area *va; | |
2357 | int i, j; | |
2358 | ||
2359 | if (unlikely(!vmap_initialized)) | |
2360 | return NULL; | |
2361 | ||
2362 | /* | |
2363 | * An addr_to_node_id(addr) converts an address to a node index | |
2364 | * where a VA is located. If VA spans several zones and passed | |
2365 | * addr is not the same as va->va_start, what is not common, we | |
2366 | * may need to scan extra nodes. See an example: | |
2367 | * | |
2368 | * <----va----> | |
2369 | * -|-----|-----|-----|-----|- | |
2370 | * 1 2 0 1 | |
2371 | * | |
2372 | * VA resides in node 1 whereas it spans 1, 2 an 0. If passed | |
2373 | * addr is within 2 or 0 nodes we should do extra work. | |
2374 | */ | |
2375 | i = j = addr_to_node_id(addr); | |
2376 | do { | |
2377 | vn = &vmap_nodes[i]; | |
2378 | ||
2379 | spin_lock(&vn->busy.lock); | |
2380 | va = __find_vmap_area(addr, &vn->busy.root); | |
2381 | spin_unlock(&vn->busy.lock); | |
2382 | ||
2383 | if (va) | |
2384 | return va; | |
2385 | } while ((i = (i + 1) % nr_vmap_nodes) != j); | |
2386 | ||
2387 | return NULL; | |
2388 | } | |
2389 | ||
2390 | static struct vmap_area *find_unlink_vmap_area(unsigned long addr) | |
2391 | { | |
2392 | struct vmap_node *vn; | |
2393 | struct vmap_area *va; | |
2394 | int i, j; | |
2395 | ||
2396 | /* | |
2397 | * Check the comment in the find_vmap_area() about the loop. | |
2398 | */ | |
2399 | i = j = addr_to_node_id(addr); | |
2400 | do { | |
2401 | vn = &vmap_nodes[i]; | |
2402 | ||
2403 | spin_lock(&vn->busy.lock); | |
2404 | va = __find_vmap_area(addr, &vn->busy.root); | |
2405 | if (va) | |
2406 | unlink_va(va, &vn->busy.root); | |
2407 | spin_unlock(&vn->busy.lock); | |
2408 | ||
2409 | if (va) | |
2410 | return va; | |
2411 | } while ((i = (i + 1) % nr_vmap_nodes) != j); | |
2412 | ||
2413 | return NULL; | |
2414 | } | |
2415 | ||
2416 | /*** Per cpu kva allocator ***/ | |
2417 | ||
2418 | /* | |
2419 | * vmap space is limited especially on 32 bit architectures. Ensure there is | |
2420 | * room for at least 16 percpu vmap blocks per CPU. | |
2421 | */ | |
2422 | /* | |
2423 | * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able | |
2424 | * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess | |
2425 | * instead (we just need a rough idea) | |
2426 | */ | |
2427 | #if BITS_PER_LONG == 32 | |
2428 | #define VMALLOC_SPACE (128UL*1024*1024) | |
2429 | #else | |
2430 | #define VMALLOC_SPACE (128UL*1024*1024*1024) | |
2431 | #endif | |
2432 | ||
2433 | #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE) | |
2434 | #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */ | |
2435 | #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */ | |
2436 | #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2) | |
2437 | #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */ | |
2438 | #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */ | |
2439 | #define VMAP_BBMAP_BITS \ | |
2440 | VMAP_MIN(VMAP_BBMAP_BITS_MAX, \ | |
2441 | VMAP_MAX(VMAP_BBMAP_BITS_MIN, \ | |
2442 | VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16)) | |
2443 | ||
2444 | #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) | |
2445 | ||
2446 | /* | |
2447 | * Purge threshold to prevent overeager purging of fragmented blocks for | |
2448 | * regular operations: Purge if vb->free is less than 1/4 of the capacity. | |
2449 | */ | |
2450 | #define VMAP_PURGE_THRESHOLD (VMAP_BBMAP_BITS / 4) | |
2451 | ||
2452 | #define VMAP_RAM 0x1 /* indicates vm_map_ram area*/ | |
2453 | #define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/ | |
2454 | #define VMAP_FLAGS_MASK 0x3 | |
2455 | ||
2456 | struct vmap_block_queue { | |
2457 | spinlock_t lock; | |
2458 | struct list_head free; | |
2459 | ||
2460 | /* | |
2461 | * An xarray requires an extra memory dynamically to | |
2462 | * be allocated. If it is an issue, we can use rb-tree | |
2463 | * instead. | |
2464 | */ | |
2465 | struct xarray vmap_blocks; | |
2466 | }; | |
2467 | ||
2468 | struct vmap_block { | |
2469 | spinlock_t lock; | |
2470 | struct vmap_area *va; | |
2471 | unsigned long free, dirty; | |
2472 | DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS); | |
2473 | unsigned long dirty_min, dirty_max; /*< dirty range */ | |
2474 | struct list_head free_list; | |
2475 | struct rcu_head rcu_head; | |
2476 | struct list_head purge; | |
2477 | }; | |
2478 | ||
2479 | /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */ | |
2480 | static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue); | |
2481 | ||
2482 | /* | |
2483 | * In order to fast access to any "vmap_block" associated with a | |
2484 | * specific address, we use a hash. | |
2485 | * | |
2486 | * A per-cpu vmap_block_queue is used in both ways, to serialize | |
2487 | * an access to free block chains among CPUs(alloc path) and it | |
2488 | * also acts as a vmap_block hash(alloc/free paths). It means we | |
2489 | * overload it, since we already have the per-cpu array which is | |
2490 | * used as a hash table. When used as a hash a 'cpu' passed to | |
2491 | * per_cpu() is not actually a CPU but rather a hash index. | |
2492 | * | |
2493 | * A hash function is addr_to_vb_xa() which hashes any address | |
2494 | * to a specific index(in a hash) it belongs to. This then uses a | |
2495 | * per_cpu() macro to access an array with generated index. | |
2496 | * | |
2497 | * An example: | |
2498 | * | |
2499 | * CPU_1 CPU_2 CPU_0 | |
2500 | * | | | | |
2501 | * V V V | |
2502 | * 0 10 20 30 40 50 60 | |
2503 | * |------|------|------|------|------|------|...<vmap address space> | |
2504 | * CPU0 CPU1 CPU2 CPU0 CPU1 CPU2 | |
2505 | * | |
2506 | * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus | |
2507 | * it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock; | |
2508 | * | |
2509 | * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus | |
2510 | * it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock; | |
2511 | * | |
2512 | * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus | |
2513 | * it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock. | |
2514 | * | |
2515 | * This technique almost always avoids lock contention on insert/remove, | |
2516 | * however xarray spinlocks protect against any contention that remains. | |
2517 | */ | |
2518 | static struct xarray * | |
2519 | addr_to_vb_xa(unsigned long addr) | |
2520 | { | |
2521 | int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus(); | |
2522 | ||
2523 | return &per_cpu(vmap_block_queue, index).vmap_blocks; | |
2524 | } | |
2525 | ||
2526 | /* | |
2527 | * We should probably have a fallback mechanism to allocate virtual memory | |
2528 | * out of partially filled vmap blocks. However vmap block sizing should be | |
2529 | * fairly reasonable according to the vmalloc size, so it shouldn't be a | |
2530 | * big problem. | |
2531 | */ | |
2532 | ||
2533 | static unsigned long addr_to_vb_idx(unsigned long addr) | |
2534 | { | |
2535 | addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1); | |
2536 | addr /= VMAP_BLOCK_SIZE; | |
2537 | return addr; | |
2538 | } | |
2539 | ||
2540 | static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) | |
2541 | { | |
2542 | unsigned long addr; | |
2543 | ||
2544 | addr = va_start + (pages_off << PAGE_SHIFT); | |
2545 | BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start)); | |
2546 | return (void *)addr; | |
2547 | } | |
2548 | ||
2549 | /** | |
2550 | * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this | |
2551 | * block. Of course pages number can't exceed VMAP_BBMAP_BITS | |
2552 | * @order: how many 2^order pages should be occupied in newly allocated block | |
2553 | * @gfp_mask: flags for the page level allocator | |
2554 | * | |
2555 | * Return: virtual address in a newly allocated block or ERR_PTR(-errno) | |
2556 | */ | |
2557 | static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) | |
2558 | { | |
2559 | struct vmap_block_queue *vbq; | |
2560 | struct vmap_block *vb; | |
2561 | struct vmap_area *va; | |
2562 | struct xarray *xa; | |
2563 | unsigned long vb_idx; | |
2564 | int node, err; | |
2565 | void *vaddr; | |
2566 | ||
2567 | node = numa_node_id(); | |
2568 | ||
2569 | vb = kmalloc_node(sizeof(struct vmap_block), | |
2570 | gfp_mask & GFP_RECLAIM_MASK, node); | |
2571 | if (unlikely(!vb)) | |
2572 | return ERR_PTR(-ENOMEM); | |
2573 | ||
2574 | va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, | |
2575 | VMALLOC_START, VMALLOC_END, | |
2576 | node, gfp_mask, | |
2577 | VMAP_RAM|VMAP_BLOCK); | |
2578 | if (IS_ERR(va)) { | |
2579 | kfree(vb); | |
2580 | return ERR_CAST(va); | |
2581 | } | |
2582 | ||
2583 | vaddr = vmap_block_vaddr(va->va_start, 0); | |
2584 | spin_lock_init(&vb->lock); | |
2585 | vb->va = va; | |
2586 | /* At least something should be left free */ | |
2587 | BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); | |
2588 | bitmap_zero(vb->used_map, VMAP_BBMAP_BITS); | |
2589 | vb->free = VMAP_BBMAP_BITS - (1UL << order); | |
2590 | vb->dirty = 0; | |
2591 | vb->dirty_min = VMAP_BBMAP_BITS; | |
2592 | vb->dirty_max = 0; | |
2593 | bitmap_set(vb->used_map, 0, (1UL << order)); | |
2594 | INIT_LIST_HEAD(&vb->free_list); | |
2595 | ||
2596 | xa = addr_to_vb_xa(va->va_start); | |
2597 | vb_idx = addr_to_vb_idx(va->va_start); | |
2598 | err = xa_insert(xa, vb_idx, vb, gfp_mask); | |
2599 | if (err) { | |
2600 | kfree(vb); | |
2601 | free_vmap_area(va); | |
2602 | return ERR_PTR(err); | |
2603 | } | |
2604 | ||
2605 | vbq = raw_cpu_ptr(&vmap_block_queue); | |
2606 | spin_lock(&vbq->lock); | |
2607 | list_add_tail_rcu(&vb->free_list, &vbq->free); | |
2608 | spin_unlock(&vbq->lock); | |
2609 | ||
2610 | return vaddr; | |
2611 | } | |
2612 | ||
2613 | static void free_vmap_block(struct vmap_block *vb) | |
2614 | { | |
2615 | struct vmap_node *vn; | |
2616 | struct vmap_block *tmp; | |
2617 | struct xarray *xa; | |
2618 | ||
2619 | xa = addr_to_vb_xa(vb->va->va_start); | |
2620 | tmp = xa_erase(xa, addr_to_vb_idx(vb->va->va_start)); | |
2621 | BUG_ON(tmp != vb); | |
2622 | ||
2623 | vn = addr_to_node(vb->va->va_start); | |
2624 | spin_lock(&vn->busy.lock); | |
2625 | unlink_va(vb->va, &vn->busy.root); | |
2626 | spin_unlock(&vn->busy.lock); | |
2627 | ||
2628 | free_vmap_area_noflush(vb->va); | |
2629 | kfree_rcu(vb, rcu_head); | |
2630 | } | |
2631 | ||
2632 | static bool purge_fragmented_block(struct vmap_block *vb, | |
2633 | struct vmap_block_queue *vbq, struct list_head *purge_list, | |
2634 | bool force_purge) | |
2635 | { | |
2636 | if (vb->free + vb->dirty != VMAP_BBMAP_BITS || | |
2637 | vb->dirty == VMAP_BBMAP_BITS) | |
2638 | return false; | |
2639 | ||
2640 | /* Don't overeagerly purge usable blocks unless requested */ | |
2641 | if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) | |
2642 | return false; | |
2643 | ||
2644 | /* prevent further allocs after releasing lock */ | |
2645 | WRITE_ONCE(vb->free, 0); | |
2646 | /* prevent purging it again */ | |
2647 | WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS); | |
2648 | vb->dirty_min = 0; | |
2649 | vb->dirty_max = VMAP_BBMAP_BITS; | |
2650 | spin_lock(&vbq->lock); | |
2651 | list_del_rcu(&vb->free_list); | |
2652 | spin_unlock(&vbq->lock); | |
2653 | list_add_tail(&vb->purge, purge_list); | |
2654 | return true; | |
2655 | } | |
2656 | ||
2657 | static void free_purged_blocks(struct list_head *purge_list) | |
2658 | { | |
2659 | struct vmap_block *vb, *n_vb; | |
2660 | ||
2661 | list_for_each_entry_safe(vb, n_vb, purge_list, purge) { | |
2662 | list_del(&vb->purge); | |
2663 | free_vmap_block(vb); | |
2664 | } | |
2665 | } | |
2666 | ||
2667 | static void purge_fragmented_blocks(int cpu) | |
2668 | { | |
2669 | LIST_HEAD(purge); | |
2670 | struct vmap_block *vb; | |
2671 | struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); | |
2672 | ||
2673 | rcu_read_lock(); | |
2674 | list_for_each_entry_rcu(vb, &vbq->free, free_list) { | |
2675 | unsigned long free = READ_ONCE(vb->free); | |
2676 | unsigned long dirty = READ_ONCE(vb->dirty); | |
2677 | ||
2678 | if (free + dirty != VMAP_BBMAP_BITS || | |
2679 | dirty == VMAP_BBMAP_BITS) | |
2680 | continue; | |
2681 | ||
2682 | spin_lock(&vb->lock); | |
2683 | purge_fragmented_block(vb, vbq, &purge, true); | |
2684 | spin_unlock(&vb->lock); | |
2685 | } | |
2686 | rcu_read_unlock(); | |
2687 | free_purged_blocks(&purge); | |
2688 | } | |
2689 | ||
2690 | static void purge_fragmented_blocks_allcpus(void) | |
2691 | { | |
2692 | int cpu; | |
2693 | ||
2694 | for_each_possible_cpu(cpu) | |
2695 | purge_fragmented_blocks(cpu); | |
2696 | } | |
2697 | ||
2698 | static void *vb_alloc(unsigned long size, gfp_t gfp_mask) | |
2699 | { | |
2700 | struct vmap_block_queue *vbq; | |
2701 | struct vmap_block *vb; | |
2702 | void *vaddr = NULL; | |
2703 | unsigned int order; | |
2704 | ||
2705 | BUG_ON(offset_in_page(size)); | |
2706 | BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); | |
2707 | if (WARN_ON(size == 0)) { | |
2708 | /* | |
2709 | * Allocating 0 bytes isn't what caller wants since | |
2710 | * get_order(0) returns funny result. Just warn and terminate | |
2711 | * early. | |
2712 | */ | |
2713 | return NULL; | |
2714 | } | |
2715 | order = get_order(size); | |
2716 | ||
2717 | rcu_read_lock(); | |
2718 | vbq = raw_cpu_ptr(&vmap_block_queue); | |
2719 | list_for_each_entry_rcu(vb, &vbq->free, free_list) { | |
2720 | unsigned long pages_off; | |
2721 | ||
2722 | if (READ_ONCE(vb->free) < (1UL << order)) | |
2723 | continue; | |
2724 | ||
2725 | spin_lock(&vb->lock); | |
2726 | if (vb->free < (1UL << order)) { | |
2727 | spin_unlock(&vb->lock); | |
2728 | continue; | |
2729 | } | |
2730 | ||
2731 | pages_off = VMAP_BBMAP_BITS - vb->free; | |
2732 | vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); | |
2733 | WRITE_ONCE(vb->free, vb->free - (1UL << order)); | |
2734 | bitmap_set(vb->used_map, pages_off, (1UL << order)); | |
2735 | if (vb->free == 0) { | |
2736 | spin_lock(&vbq->lock); | |
2737 | list_del_rcu(&vb->free_list); | |
2738 | spin_unlock(&vbq->lock); | |
2739 | } | |
2740 | ||
2741 | spin_unlock(&vb->lock); | |
2742 | break; | |
2743 | } | |
2744 | ||
2745 | rcu_read_unlock(); | |
2746 | ||
2747 | /* Allocate new block if nothing was found */ | |
2748 | if (!vaddr) | |
2749 | vaddr = new_vmap_block(order, gfp_mask); | |
2750 | ||
2751 | return vaddr; | |
2752 | } | |
2753 | ||
2754 | static void vb_free(unsigned long addr, unsigned long size) | |
2755 | { | |
2756 | unsigned long offset; | |
2757 | unsigned int order; | |
2758 | struct vmap_block *vb; | |
2759 | struct xarray *xa; | |
2760 | ||
2761 | BUG_ON(offset_in_page(size)); | |
2762 | BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); | |
2763 | ||
2764 | flush_cache_vunmap(addr, addr + size); | |
2765 | ||
2766 | order = get_order(size); | |
2767 | offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; | |
2768 | ||
2769 | xa = addr_to_vb_xa(addr); | |
2770 | vb = xa_load(xa, addr_to_vb_idx(addr)); | |
2771 | ||
2772 | spin_lock(&vb->lock); | |
2773 | bitmap_clear(vb->used_map, offset, (1UL << order)); | |
2774 | spin_unlock(&vb->lock); | |
2775 | ||
2776 | vunmap_range_noflush(addr, addr + size); | |
2777 | ||
2778 | if (debug_pagealloc_enabled_static()) | |
2779 | flush_tlb_kernel_range(addr, addr + size); | |
2780 | ||
2781 | spin_lock(&vb->lock); | |
2782 | ||
2783 | /* Expand the not yet TLB flushed dirty range */ | |
2784 | vb->dirty_min = min(vb->dirty_min, offset); | |
2785 | vb->dirty_max = max(vb->dirty_max, offset + (1UL << order)); | |
2786 | ||
2787 | WRITE_ONCE(vb->dirty, vb->dirty + (1UL << order)); | |
2788 | if (vb->dirty == VMAP_BBMAP_BITS) { | |
2789 | BUG_ON(vb->free); | |
2790 | spin_unlock(&vb->lock); | |
2791 | free_vmap_block(vb); | |
2792 | } else | |
2793 | spin_unlock(&vb->lock); | |
2794 | } | |
2795 | ||
2796 | static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) | |
2797 | { | |
2798 | LIST_HEAD(purge_list); | |
2799 | int cpu; | |
2800 | ||
2801 | if (unlikely(!vmap_initialized)) | |
2802 | return; | |
2803 | ||
2804 | mutex_lock(&vmap_purge_lock); | |
2805 | ||
2806 | for_each_possible_cpu(cpu) { | |
2807 | struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); | |
2808 | struct vmap_block *vb; | |
2809 | unsigned long idx; | |
2810 | ||
2811 | rcu_read_lock(); | |
2812 | xa_for_each(&vbq->vmap_blocks, idx, vb) { | |
2813 | spin_lock(&vb->lock); | |
2814 | ||
2815 | /* | |
2816 | * Try to purge a fragmented block first. If it's | |
2817 | * not purgeable, check whether there is dirty | |
2818 | * space to be flushed. | |
2819 | */ | |
2820 | if (!purge_fragmented_block(vb, vbq, &purge_list, false) && | |
2821 | vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { | |
2822 | unsigned long va_start = vb->va->va_start; | |
2823 | unsigned long s, e; | |
2824 | ||
2825 | s = va_start + (vb->dirty_min << PAGE_SHIFT); | |
2826 | e = va_start + (vb->dirty_max << PAGE_SHIFT); | |
2827 | ||
2828 | start = min(s, start); | |
2829 | end = max(e, end); | |
2830 | ||
2831 | /* Prevent that this is flushed again */ | |
2832 | vb->dirty_min = VMAP_BBMAP_BITS; | |
2833 | vb->dirty_max = 0; | |
2834 | ||
2835 | flush = 1; | |
2836 | } | |
2837 | spin_unlock(&vb->lock); | |
2838 | } | |
2839 | rcu_read_unlock(); | |
2840 | } | |
2841 | free_purged_blocks(&purge_list); | |
2842 | ||
2843 | if (!__purge_vmap_area_lazy(start, end, false) && flush) | |
2844 | flush_tlb_kernel_range(start, end); | |
2845 | mutex_unlock(&vmap_purge_lock); | |
2846 | } | |
2847 | ||
2848 | /** | |
2849 | * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer | |
2850 | * | |
2851 | * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily | |
2852 | * to amortize TLB flushing overheads. What this means is that any page you | |
2853 | * have now, may, in a former life, have been mapped into kernel virtual | |
2854 | * address by the vmap layer and so there might be some CPUs with TLB entries | |
2855 | * still referencing that page (additional to the regular 1:1 kernel mapping). | |
2856 | * | |
2857 | * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can | |
2858 | * be sure that none of the pages we have control over will have any aliases | |
2859 | * from the vmap layer. | |
2860 | */ | |
2861 | void vm_unmap_aliases(void) | |
2862 | { | |
2863 | unsigned long start = ULONG_MAX, end = 0; | |
2864 | int flush = 0; | |
2865 | ||
2866 | _vm_unmap_aliases(start, end, flush); | |
2867 | } | |
2868 | EXPORT_SYMBOL_GPL(vm_unmap_aliases); | |
2869 | ||
2870 | /** | |
2871 | * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram | |
2872 | * @mem: the pointer returned by vm_map_ram | |
2873 | * @count: the count passed to that vm_map_ram call (cannot unmap partial) | |
2874 | */ | |
2875 | void vm_unmap_ram(const void *mem, unsigned int count) | |
2876 | { | |
2877 | unsigned long size = (unsigned long)count << PAGE_SHIFT; | |
2878 | unsigned long addr = (unsigned long)kasan_reset_tag(mem); | |
2879 | struct vmap_area *va; | |
2880 | ||
2881 | might_sleep(); | |
2882 | BUG_ON(!addr); | |
2883 | BUG_ON(addr < VMALLOC_START); | |
2884 | BUG_ON(addr > VMALLOC_END); | |
2885 | BUG_ON(!PAGE_ALIGNED(addr)); | |
2886 | ||
2887 | kasan_poison_vmalloc(mem, size); | |
2888 | ||
2889 | if (likely(count <= VMAP_MAX_ALLOC)) { | |
2890 | debug_check_no_locks_freed(mem, size); | |
2891 | vb_free(addr, size); | |
2892 | return; | |
2893 | } | |
2894 | ||
2895 | va = find_unlink_vmap_area(addr); | |
2896 | if (WARN_ON_ONCE(!va)) | |
2897 | return; | |
2898 | ||
2899 | debug_check_no_locks_freed((void *)va->va_start, | |
2900 | (va->va_end - va->va_start)); | |
2901 | free_unmap_vmap_area(va); | |
2902 | } | |
2903 | EXPORT_SYMBOL(vm_unmap_ram); | |
2904 | ||
2905 | /** | |
2906 | * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space) | |
2907 | * @pages: an array of pointers to the pages to be mapped | |
2908 | * @count: number of pages | |
2909 | * @node: prefer to allocate data structures on this node | |
2910 | * | |
2911 | * If you use this function for less than VMAP_MAX_ALLOC pages, it could be | |
2912 | * faster than vmap so it's good. But if you mix long-life and short-life | |
2913 | * objects with vm_map_ram(), it could consume lots of address space through | |
2914 | * fragmentation (especially on a 32bit machine). You could see failures in | |
2915 | * the end. Please use this function for short-lived objects. | |
2916 | * | |
2917 | * Returns: a pointer to the address that has been mapped, or %NULL on failure | |
2918 | */ | |
2919 | void *vm_map_ram(struct page **pages, unsigned int count, int node) | |
2920 | { | |
2921 | unsigned long size = (unsigned long)count << PAGE_SHIFT; | |
2922 | unsigned long addr; | |
2923 | void *mem; | |
2924 | ||
2925 | if (likely(count <= VMAP_MAX_ALLOC)) { | |
2926 | mem = vb_alloc(size, GFP_KERNEL); | |
2927 | if (IS_ERR(mem)) | |
2928 | return NULL; | |
2929 | addr = (unsigned long)mem; | |
2930 | } else { | |
2931 | struct vmap_area *va; | |
2932 | va = alloc_vmap_area(size, PAGE_SIZE, | |
2933 | VMALLOC_START, VMALLOC_END, | |
2934 | node, GFP_KERNEL, VMAP_RAM); | |
2935 | if (IS_ERR(va)) | |
2936 | return NULL; | |
2937 | ||
2938 | addr = va->va_start; | |
2939 | mem = (void *)addr; | |
2940 | } | |
2941 | ||
2942 | if (vmap_pages_range(addr, addr + size, PAGE_KERNEL, | |
2943 | pages, PAGE_SHIFT) < 0) { | |
2944 | vm_unmap_ram(mem, count); | |
2945 | return NULL; | |
2946 | } | |
2947 | ||
2948 | /* | |
2949 | * Mark the pages as accessible, now that they are mapped. | |
2950 | * With hardware tag-based KASAN, marking is skipped for | |
2951 | * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). | |
2952 | */ | |
2953 | mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL); | |
2954 | ||
2955 | return mem; | |
2956 | } | |
2957 | EXPORT_SYMBOL(vm_map_ram); | |
2958 | ||
2959 | static struct vm_struct *vmlist __initdata; | |
2960 | ||
2961 | static inline unsigned int vm_area_page_order(struct vm_struct *vm) | |
2962 | { | |
2963 | #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC | |
2964 | return vm->page_order; | |
2965 | #else | |
2966 | return 0; | |
2967 | #endif | |
2968 | } | |
2969 | ||
2970 | static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order) | |
2971 | { | |
2972 | #ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC | |
2973 | vm->page_order = order; | |
2974 | #else | |
2975 | BUG_ON(order != 0); | |
2976 | #endif | |
2977 | } | |
2978 | ||
2979 | /** | |
2980 | * vm_area_add_early - add vmap area early during boot | |
2981 | * @vm: vm_struct to add | |
2982 | * | |
2983 | * This function is used to add fixed kernel vm area to vmlist before | |
2984 | * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags | |
2985 | * should contain proper values and the other fields should be zero. | |
2986 | * | |
2987 | * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. | |
2988 | */ | |
2989 | void __init vm_area_add_early(struct vm_struct *vm) | |
2990 | { | |
2991 | struct vm_struct *tmp, **p; | |
2992 | ||
2993 | BUG_ON(vmap_initialized); | |
2994 | for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) { | |
2995 | if (tmp->addr >= vm->addr) { | |
2996 | BUG_ON(tmp->addr < vm->addr + vm->size); | |
2997 | break; | |
2998 | } else | |
2999 | BUG_ON(tmp->addr + tmp->size > vm->addr); | |
3000 | } | |
3001 | vm->next = *p; | |
3002 | *p = vm; | |
3003 | } | |
3004 | ||
3005 | /** | |
3006 | * vm_area_register_early - register vmap area early during boot | |
3007 | * @vm: vm_struct to register | |
3008 | * @align: requested alignment | |
3009 | * | |
3010 | * This function is used to register kernel vm area before | |
3011 | * vmalloc_init() is called. @vm->size and @vm->flags should contain | |
3012 | * proper values on entry and other fields should be zero. On return, | |
3013 | * vm->addr contains the allocated address. | |
3014 | * | |
3015 | * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. | |
3016 | */ | |
3017 | void __init vm_area_register_early(struct vm_struct *vm, size_t align) | |
3018 | { | |
3019 | unsigned long addr = ALIGN(VMALLOC_START, align); | |
3020 | struct vm_struct *cur, **p; | |
3021 | ||
3022 | BUG_ON(vmap_initialized); | |
3023 | ||
3024 | for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) { | |
3025 | if ((unsigned long)cur->addr - addr >= vm->size) | |
3026 | break; | |
3027 | addr = ALIGN((unsigned long)cur->addr + cur->size, align); | |
3028 | } | |
3029 | ||
3030 | BUG_ON(addr > VMALLOC_END - vm->size); | |
3031 | vm->addr = (void *)addr; | |
3032 | vm->next = *p; | |
3033 | *p = vm; | |
3034 | kasan_populate_early_vm_area_shadow(vm->addr, vm->size); | |
3035 | } | |
3036 | ||
3037 | static inline void setup_vmalloc_vm_locked(struct vm_struct *vm, | |
3038 | struct vmap_area *va, unsigned long flags, const void *caller) | |
3039 | { | |
3040 | vm->flags = flags; | |
3041 | vm->addr = (void *)va->va_start; | |
3042 | vm->size = va->va_end - va->va_start; | |
3043 | vm->caller = caller; | |
3044 | va->vm = vm; | |
3045 | } | |
3046 | ||
3047 | static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, | |
3048 | unsigned long flags, const void *caller) | |
3049 | { | |
3050 | struct vmap_node *vn = addr_to_node(va->va_start); | |
3051 | ||
3052 | spin_lock(&vn->busy.lock); | |
3053 | setup_vmalloc_vm_locked(vm, va, flags, caller); | |
3054 | spin_unlock(&vn->busy.lock); | |
3055 | } | |
3056 | ||
3057 | static void clear_vm_uninitialized_flag(struct vm_struct *vm) | |
3058 | { | |
3059 | /* | |
3060 | * Before removing VM_UNINITIALIZED, | |
3061 | * we should make sure that vm has proper values. | |
3062 | * Pair with smp_rmb() in show_numa_info(). | |
3063 | */ | |
3064 | smp_wmb(); | |
3065 | vm->flags &= ~VM_UNINITIALIZED; | |
3066 | } | |
3067 | ||
3068 | static struct vm_struct *__get_vm_area_node(unsigned long size, | |
3069 | unsigned long align, unsigned long shift, unsigned long flags, | |
3070 | unsigned long start, unsigned long end, int node, | |
3071 | gfp_t gfp_mask, const void *caller) | |
3072 | { | |
3073 | struct vmap_area *va; | |
3074 | struct vm_struct *area; | |
3075 | unsigned long requested_size = size; | |
3076 | ||
3077 | BUG_ON(in_interrupt()); | |
3078 | size = ALIGN(size, 1ul << shift); | |
3079 | if (unlikely(!size)) | |
3080 | return NULL; | |
3081 | ||
3082 | if (flags & VM_IOREMAP) | |
3083 | align = 1ul << clamp_t(int, get_count_order_long(size), | |
3084 | PAGE_SHIFT, IOREMAP_MAX_ORDER); | |
3085 | ||
3086 | area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); | |
3087 | if (unlikely(!area)) | |
3088 | return NULL; | |
3089 | ||
3090 | if (!(flags & VM_NO_GUARD)) | |
3091 | size += PAGE_SIZE; | |
3092 | ||
3093 | va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0); | |
3094 | if (IS_ERR(va)) { | |
3095 | kfree(area); | |
3096 | return NULL; | |
3097 | } | |
3098 | ||
3099 | setup_vmalloc_vm(area, va, flags, caller); | |
3100 | ||
3101 | /* | |
3102 | * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a | |
3103 | * best-effort approach, as they can be mapped outside of vmalloc code. | |
3104 | * For VM_ALLOC mappings, the pages are marked as accessible after | |
3105 | * getting mapped in __vmalloc_node_range(). | |
3106 | * With hardware tag-based KASAN, marking is skipped for | |
3107 | * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). | |
3108 | */ | |
3109 | if (!(flags & VM_ALLOC)) | |
3110 | area->addr = kasan_unpoison_vmalloc(area->addr, requested_size, | |
3111 | KASAN_VMALLOC_PROT_NORMAL); | |
3112 | ||
3113 | return area; | |
3114 | } | |
3115 | ||
3116 | struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, | |
3117 | unsigned long start, unsigned long end, | |
3118 | const void *caller) | |
3119 | { | |
3120 | return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end, | |
3121 | NUMA_NO_NODE, GFP_KERNEL, caller); | |
3122 | } | |
3123 | ||
3124 | /** | |
3125 | * get_vm_area - reserve a contiguous kernel virtual area | |
3126 | * @size: size of the area | |
3127 | * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC | |
3128 | * | |
3129 | * Search an area of @size in the kernel virtual mapping area, | |
3130 | * and reserved it for out purposes. Returns the area descriptor | |
3131 | * on success or %NULL on failure. | |
3132 | * | |
3133 | * Return: the area descriptor on success or %NULL on failure. | |
3134 | */ | |
3135 | struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) | |
3136 | { | |
3137 | return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, | |
3138 | VMALLOC_START, VMALLOC_END, | |
3139 | NUMA_NO_NODE, GFP_KERNEL, | |
3140 | __builtin_return_address(0)); | |
3141 | } | |
3142 | ||
3143 | struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, | |
3144 | const void *caller) | |
3145 | { | |
3146 | return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, | |
3147 | VMALLOC_START, VMALLOC_END, | |
3148 | NUMA_NO_NODE, GFP_KERNEL, caller); | |
3149 | } | |
3150 | ||
3151 | /** | |
3152 | * find_vm_area - find a continuous kernel virtual area | |
3153 | * @addr: base address | |
3154 | * | |
3155 | * Search for the kernel VM area starting at @addr, and return it. | |
3156 | * It is up to the caller to do all required locking to keep the returned | |
3157 | * pointer valid. | |
3158 | * | |
3159 | * Return: the area descriptor on success or %NULL on failure. | |
3160 | */ | |
3161 | struct vm_struct *find_vm_area(const void *addr) | |
3162 | { | |
3163 | struct vmap_area *va; | |
3164 | ||
3165 | va = find_vmap_area((unsigned long)addr); | |
3166 | if (!va) | |
3167 | return NULL; | |
3168 | ||
3169 | return va->vm; | |
3170 | } | |
3171 | ||
3172 | /** | |
3173 | * remove_vm_area - find and remove a continuous kernel virtual area | |
3174 | * @addr: base address | |
3175 | * | |
3176 | * Search for the kernel VM area starting at @addr, and remove it. | |
3177 | * This function returns the found VM area, but using it is NOT safe | |
3178 | * on SMP machines, except for its size or flags. | |
3179 | * | |
3180 | * Return: the area descriptor on success or %NULL on failure. | |
3181 | */ | |
3182 | struct vm_struct *remove_vm_area(const void *addr) | |
3183 | { | |
3184 | struct vmap_area *va; | |
3185 | struct vm_struct *vm; | |
3186 | ||
3187 | might_sleep(); | |
3188 | ||
3189 | if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n", | |
3190 | addr)) | |
3191 | return NULL; | |
3192 | ||
3193 | va = find_unlink_vmap_area((unsigned long)addr); | |
3194 | if (!va || !va->vm) | |
3195 | return NULL; | |
3196 | vm = va->vm; | |
3197 | ||
3198 | debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm)); | |
3199 | debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm)); | |
3200 | kasan_free_module_shadow(vm); | |
3201 | kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm)); | |
3202 | ||
3203 | free_unmap_vmap_area(va); | |
3204 | return vm; | |
3205 | } | |
3206 | ||
3207 | static inline void set_area_direct_map(const struct vm_struct *area, | |
3208 | int (*set_direct_map)(struct page *page)) | |
3209 | { | |
3210 | int i; | |
3211 | ||
3212 | /* HUGE_VMALLOC passes small pages to set_direct_map */ | |
3213 | for (i = 0; i < area->nr_pages; i++) | |
3214 | if (page_address(area->pages[i])) | |
3215 | set_direct_map(area->pages[i]); | |
3216 | } | |
3217 | ||
3218 | /* | |
3219 | * Flush the vm mapping and reset the direct map. | |
3220 | */ | |
3221 | static void vm_reset_perms(struct vm_struct *area) | |
3222 | { | |
3223 | unsigned long start = ULONG_MAX, end = 0; | |
3224 | unsigned int page_order = vm_area_page_order(area); | |
3225 | int flush_dmap = 0; | |
3226 | int i; | |
3227 | ||
3228 | /* | |
3229 | * Find the start and end range of the direct mappings to make sure that | |
3230 | * the vm_unmap_aliases() flush includes the direct map. | |
3231 | */ | |
3232 | for (i = 0; i < area->nr_pages; i += 1U << page_order) { | |
3233 | unsigned long addr = (unsigned long)page_address(area->pages[i]); | |
3234 | ||
3235 | if (addr) { | |
3236 | unsigned long page_size; | |
3237 | ||
3238 | page_size = PAGE_SIZE << page_order; | |
3239 | start = min(addr, start); | |
3240 | end = max(addr + page_size, end); | |
3241 | flush_dmap = 1; | |
3242 | } | |
3243 | } | |
3244 | ||
3245 | /* | |
3246 | * Set direct map to something invalid so that it won't be cached if | |
3247 | * there are any accesses after the TLB flush, then flush the TLB and | |
3248 | * reset the direct map permissions to the default. | |
3249 | */ | |
3250 | set_area_direct_map(area, set_direct_map_invalid_noflush); | |
3251 | _vm_unmap_aliases(start, end, flush_dmap); | |
3252 | set_area_direct_map(area, set_direct_map_default_noflush); | |
3253 | } | |
3254 | ||
3255 | static void delayed_vfree_work(struct work_struct *w) | |
3256 | { | |
3257 | struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq); | |
3258 | struct llist_node *t, *llnode; | |
3259 | ||
3260 | llist_for_each_safe(llnode, t, llist_del_all(&p->list)) | |
3261 | vfree(llnode); | |
3262 | } | |
3263 | ||
3264 | /** | |
3265 | * vfree_atomic - release memory allocated by vmalloc() | |
3266 | * @addr: memory base address | |
3267 | * | |
3268 | * This one is just like vfree() but can be called in any atomic context | |
3269 | * except NMIs. | |
3270 | */ | |
3271 | void vfree_atomic(const void *addr) | |
3272 | { | |
3273 | struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred); | |
3274 | ||
3275 | BUG_ON(in_nmi()); | |
3276 | kmemleak_free(addr); | |
3277 | ||
3278 | /* | |
3279 | * Use raw_cpu_ptr() because this can be called from preemptible | |
3280 | * context. Preemption is absolutely fine here, because the llist_add() | |
3281 | * implementation is lockless, so it works even if we are adding to | |
3282 | * another cpu's list. schedule_work() should be fine with this too. | |
3283 | */ | |
3284 | if (addr && llist_add((struct llist_node *)addr, &p->list)) | |
3285 | schedule_work(&p->wq); | |
3286 | } | |
3287 | ||
3288 | /** | |
3289 | * vfree - Release memory allocated by vmalloc() | |
3290 | * @addr: Memory base address | |
3291 | * | |
3292 | * Free the virtually continuous memory area starting at @addr, as obtained | |
3293 | * from one of the vmalloc() family of APIs. This will usually also free the | |
3294 | * physical memory underlying the virtual allocation, but that memory is | |
3295 | * reference counted, so it will not be freed until the last user goes away. | |
3296 | * | |
3297 | * If @addr is NULL, no operation is performed. | |
3298 | * | |
3299 | * Context: | |
3300 | * May sleep if called *not* from interrupt context. | |
3301 | * Must not be called in NMI context (strictly speaking, it could be | |
3302 | * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling | |
3303 | * conventions for vfree() arch-dependent would be a really bad idea). | |
3304 | */ | |
3305 | void vfree(const void *addr) | |
3306 | { | |
3307 | struct vm_struct *vm; | |
3308 | int i; | |
3309 | ||
3310 | if (unlikely(in_interrupt())) { | |
3311 | vfree_atomic(addr); | |
3312 | return; | |
3313 | } | |
3314 | ||
3315 | BUG_ON(in_nmi()); | |
3316 | kmemleak_free(addr); | |
3317 | might_sleep(); | |
3318 | ||
3319 | if (!addr) | |
3320 | return; | |
3321 | ||
3322 | vm = remove_vm_area(addr); | |
3323 | if (unlikely(!vm)) { | |
3324 | WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", | |
3325 | addr); | |
3326 | return; | |
3327 | } | |
3328 | ||
3329 | if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS)) | |
3330 | vm_reset_perms(vm); | |
3331 | for (i = 0; i < vm->nr_pages; i++) { | |
3332 | struct page *page = vm->pages[i]; | |
3333 | ||
3334 | BUG_ON(!page); | |
3335 | mod_memcg_page_state(page, MEMCG_VMALLOC, -1); | |
3336 | /* | |
3337 | * High-order allocs for huge vmallocs are split, so | |
3338 | * can be freed as an array of order-0 allocations | |
3339 | */ | |
3340 | __free_page(page); | |
3341 | cond_resched(); | |
3342 | } | |
3343 | atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages); | |
3344 | kvfree(vm->pages); | |
3345 | kfree(vm); | |
3346 | } | |
3347 | EXPORT_SYMBOL(vfree); | |
3348 | ||
3349 | /** | |
3350 | * vunmap - release virtual mapping obtained by vmap() | |
3351 | * @addr: memory base address | |
3352 | * | |
3353 | * Free the virtually contiguous memory area starting at @addr, | |
3354 | * which was created from the page array passed to vmap(). | |
3355 | * | |
3356 | * Must not be called in interrupt context. | |
3357 | */ | |
3358 | void vunmap(const void *addr) | |
3359 | { | |
3360 | struct vm_struct *vm; | |
3361 | ||
3362 | BUG_ON(in_interrupt()); | |
3363 | might_sleep(); | |
3364 | ||
3365 | if (!addr) | |
3366 | return; | |
3367 | vm = remove_vm_area(addr); | |
3368 | if (unlikely(!vm)) { | |
3369 | WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n", | |
3370 | addr); | |
3371 | return; | |
3372 | } | |
3373 | kfree(vm); | |
3374 | } | |
3375 | EXPORT_SYMBOL(vunmap); | |
3376 | ||
3377 | /** | |
3378 | * vmap - map an array of pages into virtually contiguous space | |
3379 | * @pages: array of page pointers | |
3380 | * @count: number of pages to map | |
3381 | * @flags: vm_area->flags | |
3382 | * @prot: page protection for the mapping | |
3383 | * | |
3384 | * Maps @count pages from @pages into contiguous kernel virtual space. | |
3385 | * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself | |
3386 | * (which must be kmalloc or vmalloc memory) and one reference per pages in it | |
3387 | * are transferred from the caller to vmap(), and will be freed / dropped when | |
3388 | * vfree() is called on the return value. | |
3389 | * | |
3390 | * Return: the address of the area or %NULL on failure | |
3391 | */ | |
3392 | void *vmap(struct page **pages, unsigned int count, | |
3393 | unsigned long flags, pgprot_t prot) | |
3394 | { | |
3395 | struct vm_struct *area; | |
3396 | unsigned long addr; | |
3397 | unsigned long size; /* In bytes */ | |
3398 | ||
3399 | might_sleep(); | |
3400 | ||
3401 | if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS)) | |
3402 | return NULL; | |
3403 | ||
3404 | /* | |
3405 | * Your top guard is someone else's bottom guard. Not having a top | |
3406 | * guard compromises someone else's mappings too. | |
3407 | */ | |
3408 | if (WARN_ON_ONCE(flags & VM_NO_GUARD)) | |
3409 | flags &= ~VM_NO_GUARD; | |
3410 | ||
3411 | if (count > totalram_pages()) | |
3412 | return NULL; | |
3413 | ||
3414 | size = (unsigned long)count << PAGE_SHIFT; | |
3415 | area = get_vm_area_caller(size, flags, __builtin_return_address(0)); | |
3416 | if (!area) | |
3417 | return NULL; | |
3418 | ||
3419 | addr = (unsigned long)area->addr; | |
3420 | if (vmap_pages_range(addr, addr + size, pgprot_nx(prot), | |
3421 | pages, PAGE_SHIFT) < 0) { | |
3422 | vunmap(area->addr); | |
3423 | return NULL; | |
3424 | } | |
3425 | ||
3426 | if (flags & VM_MAP_PUT_PAGES) { | |
3427 | area->pages = pages; | |
3428 | area->nr_pages = count; | |
3429 | } | |
3430 | return area->addr; | |
3431 | } | |
3432 | EXPORT_SYMBOL(vmap); | |
3433 | ||
3434 | #ifdef CONFIG_VMAP_PFN | |
3435 | struct vmap_pfn_data { | |
3436 | unsigned long *pfns; | |
3437 | pgprot_t prot; | |
3438 | unsigned int idx; | |
3439 | }; | |
3440 | ||
3441 | static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) | |
3442 | { | |
3443 | struct vmap_pfn_data *data = private; | |
3444 | unsigned long pfn = data->pfns[data->idx]; | |
3445 | pte_t ptent; | |
3446 | ||
3447 | if (WARN_ON_ONCE(pfn_valid(pfn))) | |
3448 | return -EINVAL; | |
3449 | ||
3450 | ptent = pte_mkspecial(pfn_pte(pfn, data->prot)); | |
3451 | set_pte_at(&init_mm, addr, pte, ptent); | |
3452 | ||
3453 | data->idx++; | |
3454 | return 0; | |
3455 | } | |
3456 | ||
3457 | /** | |
3458 | * vmap_pfn - map an array of PFNs into virtually contiguous space | |
3459 | * @pfns: array of PFNs | |
3460 | * @count: number of pages to map | |
3461 | * @prot: page protection for the mapping | |
3462 | * | |
3463 | * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns | |
3464 | * the start address of the mapping. | |
3465 | */ | |
3466 | void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot) | |
3467 | { | |
3468 | struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) }; | |
3469 | struct vm_struct *area; | |
3470 | ||
3471 | area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP, | |
3472 | __builtin_return_address(0)); | |
3473 | if (!area) | |
3474 | return NULL; | |
3475 | if (apply_to_page_range(&init_mm, (unsigned long)area->addr, | |
3476 | count * PAGE_SIZE, vmap_pfn_apply, &data)) { | |
3477 | free_vm_area(area); | |
3478 | return NULL; | |
3479 | } | |
3480 | ||
3481 | flush_cache_vmap((unsigned long)area->addr, | |
3482 | (unsigned long)area->addr + count * PAGE_SIZE); | |
3483 | ||
3484 | return area->addr; | |
3485 | } | |
3486 | EXPORT_SYMBOL_GPL(vmap_pfn); | |
3487 | #endif /* CONFIG_VMAP_PFN */ | |
3488 | ||
3489 | static inline unsigned int | |
3490 | vm_area_alloc_pages(gfp_t gfp, int nid, | |
3491 | unsigned int order, unsigned int nr_pages, struct page **pages) | |
3492 | { | |
3493 | unsigned int nr_allocated = 0; | |
3494 | gfp_t alloc_gfp = gfp; | |
3495 | bool nofail = false; | |
3496 | struct page *page; | |
3497 | int i; | |
3498 | ||
3499 | /* | |
3500 | * For order-0 pages we make use of bulk allocator, if | |
3501 | * the page array is partly or not at all populated due | |
3502 | * to fails, fallback to a single page allocator that is | |
3503 | * more permissive. | |
3504 | */ | |
3505 | if (!order) { | |
3506 | /* bulk allocator doesn't support nofail req. officially */ | |
3507 | gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; | |
3508 | ||
3509 | while (nr_allocated < nr_pages) { | |
3510 | unsigned int nr, nr_pages_request; | |
3511 | ||
3512 | /* | |
3513 | * A maximum allowed request is hard-coded and is 100 | |
3514 | * pages per call. That is done in order to prevent a | |
3515 | * long preemption off scenario in the bulk-allocator | |
3516 | * so the range is [1:100]. | |
3517 | */ | |
3518 | nr_pages_request = min(100U, nr_pages - nr_allocated); | |
3519 | ||
3520 | /* memory allocation should consider mempolicy, we can't | |
3521 | * wrongly use nearest node when nid == NUMA_NO_NODE, | |
3522 | * otherwise memory may be allocated in only one node, | |
3523 | * but mempolicy wants to alloc memory by interleaving. | |
3524 | */ | |
3525 | if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) | |
3526 | nr = alloc_pages_bulk_array_mempolicy(bulk_gfp, | |
3527 | nr_pages_request, | |
3528 | pages + nr_allocated); | |
3529 | ||
3530 | else | |
3531 | nr = alloc_pages_bulk_array_node(bulk_gfp, nid, | |
3532 | nr_pages_request, | |
3533 | pages + nr_allocated); | |
3534 | ||
3535 | nr_allocated += nr; | |
3536 | cond_resched(); | |
3537 | ||
3538 | /* | |
3539 | * If zero or pages were obtained partly, | |
3540 | * fallback to a single page allocator. | |
3541 | */ | |
3542 | if (nr != nr_pages_request) | |
3543 | break; | |
3544 | } | |
3545 | } else if (gfp & __GFP_NOFAIL) { | |
3546 | /* | |
3547 | * Higher order nofail allocations are really expensive and | |
3548 | * potentially dangerous (pre-mature OOM, disruptive reclaim | |
3549 | * and compaction etc. | |
3550 | */ | |
3551 | alloc_gfp &= ~__GFP_NOFAIL; | |
3552 | nofail = true; | |
3553 | } | |
3554 | ||
3555 | /* High-order pages or fallback path if "bulk" fails. */ | |
3556 | while (nr_allocated < nr_pages) { | |
3557 | if (fatal_signal_pending(current)) | |
3558 | break; | |
3559 | ||
3560 | if (nid == NUMA_NO_NODE) | |
3561 | page = alloc_pages(alloc_gfp, order); | |
3562 | else | |
3563 | page = alloc_pages_node(nid, alloc_gfp, order); | |
3564 | if (unlikely(!page)) { | |
3565 | if (!nofail) | |
3566 | break; | |
3567 | ||
3568 | /* fall back to the zero order allocations */ | |
3569 | alloc_gfp |= __GFP_NOFAIL; | |
3570 | order = 0; | |
3571 | continue; | |
3572 | } | |
3573 | ||
3574 | /* | |
3575 | * Higher order allocations must be able to be treated as | |
3576 | * indepdenent small pages by callers (as they can with | |
3577 | * small-page vmallocs). Some drivers do their own refcounting | |
3578 | * on vmalloc_to_page() pages, some use page->mapping, | |
3579 | * page->lru, etc. | |
3580 | */ | |
3581 | if (order) | |
3582 | split_page(page, order); | |
3583 | ||
3584 | /* | |
3585 | * Careful, we allocate and map page-order pages, but | |
3586 | * tracking is done per PAGE_SIZE page so as to keep the | |
3587 | * vm_struct APIs independent of the physical/mapped size. | |
3588 | */ | |
3589 | for (i = 0; i < (1U << order); i++) | |
3590 | pages[nr_allocated + i] = page + i; | |
3591 | ||
3592 | cond_resched(); | |
3593 | nr_allocated += 1U << order; | |
3594 | } | |
3595 | ||
3596 | return nr_allocated; | |
3597 | } | |
3598 | ||
3599 | static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, | |
3600 | pgprot_t prot, unsigned int page_shift, | |
3601 | int node) | |
3602 | { | |
3603 | const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; | |
3604 | bool nofail = gfp_mask & __GFP_NOFAIL; | |
3605 | unsigned long addr = (unsigned long)area->addr; | |
3606 | unsigned long size = get_vm_area_size(area); | |
3607 | unsigned long array_size; | |
3608 | unsigned int nr_small_pages = size >> PAGE_SHIFT; | |
3609 | unsigned int page_order; | |
3610 | unsigned int flags; | |
3611 | int ret; | |
3612 | ||
3613 | array_size = (unsigned long)nr_small_pages * sizeof(struct page *); | |
3614 | ||
3615 | if (!(gfp_mask & (GFP_DMA | GFP_DMA32))) | |
3616 | gfp_mask |= __GFP_HIGHMEM; | |
3617 | ||
3618 | /* Please note that the recursion is strictly bounded. */ | |
3619 | if (array_size > PAGE_SIZE) { | |
3620 | area->pages = __vmalloc_node(array_size, 1, nested_gfp, node, | |
3621 | area->caller); | |
3622 | } else { | |
3623 | area->pages = kmalloc_node(array_size, nested_gfp, node); | |
3624 | } | |
3625 | ||
3626 | if (!area->pages) { | |
3627 | warn_alloc(gfp_mask, NULL, | |
3628 | "vmalloc error: size %lu, failed to allocated page array size %lu", | |
3629 | nr_small_pages * PAGE_SIZE, array_size); | |
3630 | free_vm_area(area); | |
3631 | return NULL; | |
3632 | } | |
3633 | ||
3634 | set_vm_area_page_order(area, page_shift - PAGE_SHIFT); | |
3635 | page_order = vm_area_page_order(area); | |
3636 | ||
3637 | area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, | |
3638 | node, page_order, nr_small_pages, area->pages); | |
3639 | ||
3640 | atomic_long_add(area->nr_pages, &nr_vmalloc_pages); | |
3641 | if (gfp_mask & __GFP_ACCOUNT) { | |
3642 | int i; | |
3643 | ||
3644 | for (i = 0; i < area->nr_pages; i++) | |
3645 | mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1); | |
3646 | } | |
3647 | ||
3648 | /* | |
3649 | * If not enough pages were obtained to accomplish an | |
3650 | * allocation request, free them via vfree() if any. | |
3651 | */ | |
3652 | if (area->nr_pages != nr_small_pages) { | |
3653 | /* | |
3654 | * vm_area_alloc_pages() can fail due to insufficient memory but | |
3655 | * also:- | |
3656 | * | |
3657 | * - a pending fatal signal | |
3658 | * - insufficient huge page-order pages | |
3659 | * | |
3660 | * Since we always retry allocations at order-0 in the huge page | |
3661 | * case a warning for either is spurious. | |
3662 | */ | |
3663 | if (!fatal_signal_pending(current) && page_order == 0) | |
3664 | warn_alloc(gfp_mask, NULL, | |
3665 | "vmalloc error: size %lu, failed to allocate pages", | |
3666 | area->nr_pages * PAGE_SIZE); | |
3667 | goto fail; | |
3668 | } | |
3669 | ||
3670 | /* | |
3671 | * page tables allocations ignore external gfp mask, enforce it | |
3672 | * by the scope API | |
3673 | */ | |
3674 | if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) | |
3675 | flags = memalloc_nofs_save(); | |
3676 | else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) | |
3677 | flags = memalloc_noio_save(); | |
3678 | ||
3679 | do { | |
3680 | ret = vmap_pages_range(addr, addr + size, prot, area->pages, | |
3681 | page_shift); | |
3682 | if (nofail && (ret < 0)) | |
3683 | schedule_timeout_uninterruptible(1); | |
3684 | } while (nofail && (ret < 0)); | |
3685 | ||
3686 | if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) | |
3687 | memalloc_nofs_restore(flags); | |
3688 | else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) | |
3689 | memalloc_noio_restore(flags); | |
3690 | ||
3691 | if (ret < 0) { | |
3692 | warn_alloc(gfp_mask, NULL, | |
3693 | "vmalloc error: size %lu, failed to map pages", | |
3694 | area->nr_pages * PAGE_SIZE); | |
3695 | goto fail; | |
3696 | } | |
3697 | ||
3698 | return area->addr; | |
3699 | ||
3700 | fail: | |
3701 | vfree(area->addr); | |
3702 | return NULL; | |
3703 | } | |
3704 | ||
3705 | /** | |
3706 | * __vmalloc_node_range - allocate virtually contiguous memory | |
3707 | * @size: allocation size | |
3708 | * @align: desired alignment | |
3709 | * @start: vm area range start | |
3710 | * @end: vm area range end | |
3711 | * @gfp_mask: flags for the page level allocator | |
3712 | * @prot: protection mask for the allocated pages | |
3713 | * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) | |
3714 | * @node: node to use for allocation or NUMA_NO_NODE | |
3715 | * @caller: caller's return address | |
3716 | * | |
3717 | * Allocate enough pages to cover @size from the page level | |
3718 | * allocator with @gfp_mask flags. Please note that the full set of gfp | |
3719 | * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all | |
3720 | * supported. | |
3721 | * Zone modifiers are not supported. From the reclaim modifiers | |
3722 | * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported) | |
3723 | * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and | |
3724 | * __GFP_RETRY_MAYFAIL are not supported). | |
3725 | * | |
3726 | * __GFP_NOWARN can be used to suppress failures messages. | |
3727 | * | |
3728 | * Map them into contiguous kernel virtual space, using a pagetable | |
3729 | * protection of @prot. | |
3730 | * | |
3731 | * Return: the address of the area or %NULL on failure | |
3732 | */ | |
3733 | void *__vmalloc_node_range(unsigned long size, unsigned long align, | |
3734 | unsigned long start, unsigned long end, gfp_t gfp_mask, | |
3735 | pgprot_t prot, unsigned long vm_flags, int node, | |
3736 | const void *caller) | |
3737 | { | |
3738 | struct vm_struct *area; | |
3739 | void *ret; | |
3740 | kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE; | |
3741 | unsigned long real_size = size; | |
3742 | unsigned long real_align = align; | |
3743 | unsigned int shift = PAGE_SHIFT; | |
3744 | ||
3745 | if (WARN_ON_ONCE(!size)) | |
3746 | return NULL; | |
3747 | ||
3748 | if ((size >> PAGE_SHIFT) > totalram_pages()) { | |
3749 | warn_alloc(gfp_mask, NULL, | |
3750 | "vmalloc error: size %lu, exceeds total pages", | |
3751 | real_size); | |
3752 | return NULL; | |
3753 | } | |
3754 | ||
3755 | if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) { | |
3756 | unsigned long size_per_node; | |
3757 | ||
3758 | /* | |
3759 | * Try huge pages. Only try for PAGE_KERNEL allocations, | |
3760 | * others like modules don't yet expect huge pages in | |
3761 | * their allocations due to apply_to_page_range not | |
3762 | * supporting them. | |
3763 | */ | |
3764 | ||
3765 | size_per_node = size; | |
3766 | if (node == NUMA_NO_NODE) | |
3767 | size_per_node /= num_online_nodes(); | |
3768 | if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE) | |
3769 | shift = PMD_SHIFT; | |
3770 | else | |
3771 | shift = arch_vmap_pte_supported_shift(size_per_node); | |
3772 | ||
3773 | align = max(real_align, 1UL << shift); | |
3774 | size = ALIGN(real_size, 1UL << shift); | |
3775 | } | |
3776 | ||
3777 | again: | |
3778 | area = __get_vm_area_node(real_size, align, shift, VM_ALLOC | | |
3779 | VM_UNINITIALIZED | vm_flags, start, end, node, | |
3780 | gfp_mask, caller); | |
3781 | if (!area) { | |
3782 | bool nofail = gfp_mask & __GFP_NOFAIL; | |
3783 | warn_alloc(gfp_mask, NULL, | |
3784 | "vmalloc error: size %lu, vm_struct allocation failed%s", | |
3785 | real_size, (nofail) ? ". Retrying." : ""); | |
3786 | if (nofail) { | |
3787 | schedule_timeout_uninterruptible(1); | |
3788 | goto again; | |
3789 | } | |
3790 | goto fail; | |
3791 | } | |
3792 | ||
3793 | /* | |
3794 | * Prepare arguments for __vmalloc_area_node() and | |
3795 | * kasan_unpoison_vmalloc(). | |
3796 | */ | |
3797 | if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) { | |
3798 | if (kasan_hw_tags_enabled()) { | |
3799 | /* | |
3800 | * Modify protection bits to allow tagging. | |
3801 | * This must be done before mapping. | |
3802 | */ | |
3803 | prot = arch_vmap_pgprot_tagged(prot); | |
3804 | ||
3805 | /* | |
3806 | * Skip page_alloc poisoning and zeroing for physical | |
3807 | * pages backing VM_ALLOC mapping. Memory is instead | |
3808 | * poisoned and zeroed by kasan_unpoison_vmalloc(). | |
3809 | */ | |
3810 | gfp_mask |= __GFP_SKIP_KASAN | __GFP_SKIP_ZERO; | |
3811 | } | |
3812 | ||
3813 | /* Take note that the mapping is PAGE_KERNEL. */ | |
3814 | kasan_flags |= KASAN_VMALLOC_PROT_NORMAL; | |
3815 | } | |
3816 | ||
3817 | /* Allocate physical pages and map them into vmalloc space. */ | |
3818 | ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node); | |
3819 | if (!ret) | |
3820 | goto fail; | |
3821 | ||
3822 | /* | |
3823 | * Mark the pages as accessible, now that they are mapped. | |
3824 | * The condition for setting KASAN_VMALLOC_INIT should complement the | |
3825 | * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check | |
3826 | * to make sure that memory is initialized under the same conditions. | |
3827 | * Tag-based KASAN modes only assign tags to normal non-executable | |
3828 | * allocations, see __kasan_unpoison_vmalloc(). | |
3829 | */ | |
3830 | kasan_flags |= KASAN_VMALLOC_VM_ALLOC; | |
3831 | if (!want_init_on_free() && want_init_on_alloc(gfp_mask) && | |
3832 | (gfp_mask & __GFP_SKIP_ZERO)) | |
3833 | kasan_flags |= KASAN_VMALLOC_INIT; | |
3834 | /* KASAN_VMALLOC_PROT_NORMAL already set if required. */ | |
3835 | area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags); | |
3836 | ||
3837 | /* | |
3838 | * In this function, newly allocated vm_struct has VM_UNINITIALIZED | |
3839 | * flag. It means that vm_struct is not fully initialized. | |
3840 | * Now, it is fully initialized, so remove this flag here. | |
3841 | */ | |
3842 | clear_vm_uninitialized_flag(area); | |
3843 | ||
3844 | size = PAGE_ALIGN(size); | |
3845 | if (!(vm_flags & VM_DEFER_KMEMLEAK)) | |
3846 | kmemleak_vmalloc(area, size, gfp_mask); | |
3847 | ||
3848 | return area->addr; | |
3849 | ||
3850 | fail: | |
3851 | if (shift > PAGE_SHIFT) { | |
3852 | shift = PAGE_SHIFT; | |
3853 | align = real_align; | |
3854 | size = real_size; | |
3855 | goto again; | |
3856 | } | |
3857 | ||
3858 | return NULL; | |
3859 | } | |
3860 | ||
3861 | /** | |
3862 | * __vmalloc_node - allocate virtually contiguous memory | |
3863 | * @size: allocation size | |
3864 | * @align: desired alignment | |
3865 | * @gfp_mask: flags for the page level allocator | |
3866 | * @node: node to use for allocation or NUMA_NO_NODE | |
3867 | * @caller: caller's return address | |
3868 | * | |
3869 | * Allocate enough pages to cover @size from the page level allocator with | |
3870 | * @gfp_mask flags. Map them into contiguous kernel virtual space. | |
3871 | * | |
3872 | * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL | |
3873 | * and __GFP_NOFAIL are not supported | |
3874 | * | |
3875 | * Any use of gfp flags outside of GFP_KERNEL should be consulted | |
3876 | * with mm people. | |
3877 | * | |
3878 | * Return: pointer to the allocated memory or %NULL on error | |
3879 | */ | |
3880 | void *__vmalloc_node(unsigned long size, unsigned long align, | |
3881 | gfp_t gfp_mask, int node, const void *caller) | |
3882 | { | |
3883 | return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, | |
3884 | gfp_mask, PAGE_KERNEL, 0, node, caller); | |
3885 | } | |
3886 | /* | |
3887 | * This is only for performance analysis of vmalloc and stress purpose. | |
3888 | * It is required by vmalloc test module, therefore do not use it other | |
3889 | * than that. | |
3890 | */ | |
3891 | #ifdef CONFIG_TEST_VMALLOC_MODULE | |
3892 | EXPORT_SYMBOL_GPL(__vmalloc_node); | |
3893 | #endif | |
3894 | ||
3895 | void *__vmalloc(unsigned long size, gfp_t gfp_mask) | |
3896 | { | |
3897 | return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE, | |
3898 | __builtin_return_address(0)); | |
3899 | } | |
3900 | EXPORT_SYMBOL(__vmalloc); | |
3901 | ||
3902 | /** | |
3903 | * vmalloc - allocate virtually contiguous memory | |
3904 | * @size: allocation size | |
3905 | * | |
3906 | * Allocate enough pages to cover @size from the page level | |
3907 | * allocator and map them into contiguous kernel virtual space. | |
3908 | * | |
3909 | * For tight control over page level allocator and protection flags | |
3910 | * use __vmalloc() instead. | |
3911 | * | |
3912 | * Return: pointer to the allocated memory or %NULL on error | |
3913 | */ | |
3914 | void *vmalloc(unsigned long size) | |
3915 | { | |
3916 | return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE, | |
3917 | __builtin_return_address(0)); | |
3918 | } | |
3919 | EXPORT_SYMBOL(vmalloc); | |
3920 | ||
3921 | /** | |
3922 | * vmalloc_huge - allocate virtually contiguous memory, allow huge pages | |
3923 | * @size: allocation size | |
3924 | * @gfp_mask: flags for the page level allocator | |
3925 | * | |
3926 | * Allocate enough pages to cover @size from the page level | |
3927 | * allocator and map them into contiguous kernel virtual space. | |
3928 | * If @size is greater than or equal to PMD_SIZE, allow using | |
3929 | * huge pages for the memory | |
3930 | * | |
3931 | * Return: pointer to the allocated memory or %NULL on error | |
3932 | */ | |
3933 | void *vmalloc_huge(unsigned long size, gfp_t gfp_mask) | |
3934 | { | |
3935 | return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, | |
3936 | gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP, | |
3937 | NUMA_NO_NODE, __builtin_return_address(0)); | |
3938 | } | |
3939 | EXPORT_SYMBOL_GPL(vmalloc_huge); | |
3940 | ||
3941 | /** | |
3942 | * vzalloc - allocate virtually contiguous memory with zero fill | |
3943 | * @size: allocation size | |
3944 | * | |
3945 | * Allocate enough pages to cover @size from the page level | |
3946 | * allocator and map them into contiguous kernel virtual space. | |
3947 | * The memory allocated is set to zero. | |
3948 | * | |
3949 | * For tight control over page level allocator and protection flags | |
3950 | * use __vmalloc() instead. | |
3951 | * | |
3952 | * Return: pointer to the allocated memory or %NULL on error | |
3953 | */ | |
3954 | void *vzalloc(unsigned long size) | |
3955 | { | |
3956 | return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, | |
3957 | __builtin_return_address(0)); | |
3958 | } | |
3959 | EXPORT_SYMBOL(vzalloc); | |
3960 | ||
3961 | /** | |
3962 | * vmalloc_user - allocate zeroed virtually contiguous memory for userspace | |
3963 | * @size: allocation size | |
3964 | * | |
3965 | * The resulting memory area is zeroed so it can be mapped to userspace | |
3966 | * without leaking data. | |
3967 | * | |
3968 | * Return: pointer to the allocated memory or %NULL on error | |
3969 | */ | |
3970 | void *vmalloc_user(unsigned long size) | |
3971 | { | |
3972 | return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, | |
3973 | GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL, | |
3974 | VM_USERMAP, NUMA_NO_NODE, | |
3975 | __builtin_return_address(0)); | |
3976 | } | |
3977 | EXPORT_SYMBOL(vmalloc_user); | |
3978 | ||
3979 | /** | |
3980 | * vmalloc_node - allocate memory on a specific node | |
3981 | * @size: allocation size | |
3982 | * @node: numa node | |
3983 | * | |
3984 | * Allocate enough pages to cover @size from the page level | |
3985 | * allocator and map them into contiguous kernel virtual space. | |
3986 | * | |
3987 | * For tight control over page level allocator and protection flags | |
3988 | * use __vmalloc() instead. | |
3989 | * | |
3990 | * Return: pointer to the allocated memory or %NULL on error | |
3991 | */ | |
3992 | void *vmalloc_node(unsigned long size, int node) | |
3993 | { | |
3994 | return __vmalloc_node(size, 1, GFP_KERNEL, node, | |
3995 | __builtin_return_address(0)); | |
3996 | } | |
3997 | EXPORT_SYMBOL(vmalloc_node); | |
3998 | ||
3999 | /** | |
4000 | * vzalloc_node - allocate memory on a specific node with zero fill | |
4001 | * @size: allocation size | |
4002 | * @node: numa node | |
4003 | * | |
4004 | * Allocate enough pages to cover @size from the page level | |
4005 | * allocator and map them into contiguous kernel virtual space. | |
4006 | * The memory allocated is set to zero. | |
4007 | * | |
4008 | * Return: pointer to the allocated memory or %NULL on error | |
4009 | */ | |
4010 | void *vzalloc_node(unsigned long size, int node) | |
4011 | { | |
4012 | return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node, | |
4013 | __builtin_return_address(0)); | |
4014 | } | |
4015 | EXPORT_SYMBOL(vzalloc_node); | |
4016 | ||
4017 | #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) | |
4018 | #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) | |
4019 | #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA) | |
4020 | #define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL) | |
4021 | #else | |
4022 | /* | |
4023 | * 64b systems should always have either DMA or DMA32 zones. For others | |
4024 | * GFP_DMA32 should do the right thing and use the normal zone. | |
4025 | */ | |
4026 | #define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) | |
4027 | #endif | |
4028 | ||
4029 | /** | |
4030 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) | |
4031 | * @size: allocation size | |
4032 | * | |
4033 | * Allocate enough 32bit PA addressable pages to cover @size from the | |
4034 | * page level allocator and map them into contiguous kernel virtual space. | |
4035 | * | |
4036 | * Return: pointer to the allocated memory or %NULL on error | |
4037 | */ | |
4038 | void *vmalloc_32(unsigned long size) | |
4039 | { | |
4040 | return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE, | |
4041 | __builtin_return_address(0)); | |
4042 | } | |
4043 | EXPORT_SYMBOL(vmalloc_32); | |
4044 | ||
4045 | /** | |
4046 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory | |
4047 | * @size: allocation size | |
4048 | * | |
4049 | * The resulting memory area is 32bit addressable and zeroed so it can be | |
4050 | * mapped to userspace without leaking data. | |
4051 | * | |
4052 | * Return: pointer to the allocated memory or %NULL on error | |
4053 | */ | |
4054 | void *vmalloc_32_user(unsigned long size) | |
4055 | { | |
4056 | return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, | |
4057 | GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, | |
4058 | VM_USERMAP, NUMA_NO_NODE, | |
4059 | __builtin_return_address(0)); | |
4060 | } | |
4061 | EXPORT_SYMBOL(vmalloc_32_user); | |
4062 | ||
4063 | /* | |
4064 | * Atomically zero bytes in the iterator. | |
4065 | * | |
4066 | * Returns the number of zeroed bytes. | |
4067 | */ | |
4068 | static size_t zero_iter(struct iov_iter *iter, size_t count) | |
4069 | { | |
4070 | size_t remains = count; | |
4071 | ||
4072 | while (remains > 0) { | |
4073 | size_t num, copied; | |
4074 | ||
4075 | num = min_t(size_t, remains, PAGE_SIZE); | |
4076 | copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter); | |
4077 | remains -= copied; | |
4078 | ||
4079 | if (copied < num) | |
4080 | break; | |
4081 | } | |
4082 | ||
4083 | return count - remains; | |
4084 | } | |
4085 | ||
4086 | /* | |
4087 | * small helper routine, copy contents to iter from addr. | |
4088 | * If the page is not present, fill zero. | |
4089 | * | |
4090 | * Returns the number of copied bytes. | |
4091 | */ | |
4092 | static size_t aligned_vread_iter(struct iov_iter *iter, | |
4093 | const char *addr, size_t count) | |
4094 | { | |
4095 | size_t remains = count; | |
4096 | struct page *page; | |
4097 | ||
4098 | while (remains > 0) { | |
4099 | unsigned long offset, length; | |
4100 | size_t copied = 0; | |
4101 | ||
4102 | offset = offset_in_page(addr); | |
4103 | length = PAGE_SIZE - offset; | |
4104 | if (length > remains) | |
4105 | length = remains; | |
4106 | page = vmalloc_to_page(addr); | |
4107 | /* | |
4108 | * To do safe access to this _mapped_ area, we need lock. But | |
4109 | * adding lock here means that we need to add overhead of | |
4110 | * vmalloc()/vfree() calls for this _debug_ interface, rarely | |
4111 | * used. Instead of that, we'll use an local mapping via | |
4112 | * copy_page_to_iter_nofault() and accept a small overhead in | |
4113 | * this access function. | |
4114 | */ | |
4115 | if (page) | |
4116 | copied = copy_page_to_iter_nofault(page, offset, | |
4117 | length, iter); | |
4118 | else | |
4119 | copied = zero_iter(iter, length); | |
4120 | ||
4121 | addr += copied; | |
4122 | remains -= copied; | |
4123 | ||
4124 | if (copied != length) | |
4125 | break; | |
4126 | } | |
4127 | ||
4128 | return count - remains; | |
4129 | } | |
4130 | ||
4131 | /* | |
4132 | * Read from a vm_map_ram region of memory. | |
4133 | * | |
4134 | * Returns the number of copied bytes. | |
4135 | */ | |
4136 | static size_t vmap_ram_vread_iter(struct iov_iter *iter, const char *addr, | |
4137 | size_t count, unsigned long flags) | |
4138 | { | |
4139 | char *start; | |
4140 | struct vmap_block *vb; | |
4141 | struct xarray *xa; | |
4142 | unsigned long offset; | |
4143 | unsigned int rs, re; | |
4144 | size_t remains, n; | |
4145 | ||
4146 | /* | |
4147 | * If it's area created by vm_map_ram() interface directly, but | |
4148 | * not further subdividing and delegating management to vmap_block, | |
4149 | * handle it here. | |
4150 | */ | |
4151 | if (!(flags & VMAP_BLOCK)) | |
4152 | return aligned_vread_iter(iter, addr, count); | |
4153 | ||
4154 | remains = count; | |
4155 | ||
4156 | /* | |
4157 | * Area is split into regions and tracked with vmap_block, read out | |
4158 | * each region and zero fill the hole between regions. | |
4159 | */ | |
4160 | xa = addr_to_vb_xa((unsigned long) addr); | |
4161 | vb = xa_load(xa, addr_to_vb_idx((unsigned long)addr)); | |
4162 | if (!vb) | |
4163 | goto finished_zero; | |
4164 | ||
4165 | spin_lock(&vb->lock); | |
4166 | if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) { | |
4167 | spin_unlock(&vb->lock); | |
4168 | goto finished_zero; | |
4169 | } | |
4170 | ||
4171 | for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) { | |
4172 | size_t copied; | |
4173 | ||
4174 | if (remains == 0) | |
4175 | goto finished; | |
4176 | ||
4177 | start = vmap_block_vaddr(vb->va->va_start, rs); | |
4178 | ||
4179 | if (addr < start) { | |
4180 | size_t to_zero = min_t(size_t, start - addr, remains); | |
4181 | size_t zeroed = zero_iter(iter, to_zero); | |
4182 | ||
4183 | addr += zeroed; | |
4184 | remains -= zeroed; | |
4185 | ||
4186 | if (remains == 0 || zeroed != to_zero) | |
4187 | goto finished; | |
4188 | } | |
4189 | ||
4190 | /*it could start reading from the middle of used region*/ | |
4191 | offset = offset_in_page(addr); | |
4192 | n = ((re - rs + 1) << PAGE_SHIFT) - offset; | |
4193 | if (n > remains) | |
4194 | n = remains; | |
4195 | ||
4196 | copied = aligned_vread_iter(iter, start + offset, n); | |
4197 | ||
4198 | addr += copied; | |
4199 | remains -= copied; | |
4200 | ||
4201 | if (copied != n) | |
4202 | goto finished; | |
4203 | } | |
4204 | ||
4205 | spin_unlock(&vb->lock); | |
4206 | ||
4207 | finished_zero: | |
4208 | /* zero-fill the left dirty or free regions */ | |
4209 | return count - remains + zero_iter(iter, remains); | |
4210 | finished: | |
4211 | /* We couldn't copy/zero everything */ | |
4212 | spin_unlock(&vb->lock); | |
4213 | return count - remains; | |
4214 | } | |
4215 | ||
4216 | /** | |
4217 | * vread_iter() - read vmalloc area in a safe way to an iterator. | |
4218 | * @iter: the iterator to which data should be written. | |
4219 | * @addr: vm address. | |
4220 | * @count: number of bytes to be read. | |
4221 | * | |
4222 | * This function checks that addr is a valid vmalloc'ed area, and | |
4223 | * copy data from that area to a given buffer. If the given memory range | |
4224 | * of [addr...addr+count) includes some valid address, data is copied to | |
4225 | * proper area of @buf. If there are memory holes, they'll be zero-filled. | |
4226 | * IOREMAP area is treated as memory hole and no copy is done. | |
4227 | * | |
4228 | * If [addr...addr+count) doesn't includes any intersects with alive | |
4229 | * vm_struct area, returns 0. @buf should be kernel's buffer. | |
4230 | * | |
4231 | * Note: In usual ops, vread() is never necessary because the caller | |
4232 | * should know vmalloc() area is valid and can use memcpy(). | |
4233 | * This is for routines which have to access vmalloc area without | |
4234 | * any information, as /proc/kcore. | |
4235 | * | |
4236 | * Return: number of bytes for which addr and buf should be increased | |
4237 | * (same number as @count) or %0 if [addr...addr+count) doesn't | |
4238 | * include any intersection with valid vmalloc area | |
4239 | */ | |
4240 | long vread_iter(struct iov_iter *iter, const char *addr, size_t count) | |
4241 | { | |
4242 | struct vmap_node *vn; | |
4243 | struct vmap_area *va; | |
4244 | struct vm_struct *vm; | |
4245 | char *vaddr; | |
4246 | size_t n, size, flags, remains; | |
4247 | unsigned long next; | |
4248 | ||
4249 | addr = kasan_reset_tag(addr); | |
4250 | ||
4251 | /* Don't allow overflow */ | |
4252 | if ((unsigned long) addr + count < count) | |
4253 | count = -(unsigned long) addr; | |
4254 | ||
4255 | remains = count; | |
4256 | ||
4257 | vn = find_vmap_area_exceed_addr_lock((unsigned long) addr, &va); | |
4258 | if (!vn) | |
4259 | goto finished_zero; | |
4260 | ||
4261 | /* no intersects with alive vmap_area */ | |
4262 | if ((unsigned long)addr + remains <= va->va_start) | |
4263 | goto finished_zero; | |
4264 | ||
4265 | do { | |
4266 | size_t copied; | |
4267 | ||
4268 | if (remains == 0) | |
4269 | goto finished; | |
4270 | ||
4271 | vm = va->vm; | |
4272 | flags = va->flags & VMAP_FLAGS_MASK; | |
4273 | /* | |
4274 | * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need | |
4275 | * be set together with VMAP_RAM. | |
4276 | */ | |
4277 | WARN_ON(flags == VMAP_BLOCK); | |
4278 | ||
4279 | if (!vm && !flags) | |
4280 | goto next_va; | |
4281 | ||
4282 | if (vm && (vm->flags & VM_UNINITIALIZED)) | |
4283 | goto next_va; | |
4284 | ||
4285 | /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ | |
4286 | smp_rmb(); | |
4287 | ||
4288 | vaddr = (char *) va->va_start; | |
4289 | size = vm ? get_vm_area_size(vm) : va_size(va); | |
4290 | ||
4291 | if (addr >= vaddr + size) | |
4292 | goto next_va; | |
4293 | ||
4294 | if (addr < vaddr) { | |
4295 | size_t to_zero = min_t(size_t, vaddr - addr, remains); | |
4296 | size_t zeroed = zero_iter(iter, to_zero); | |
4297 | ||
4298 | addr += zeroed; | |
4299 | remains -= zeroed; | |
4300 | ||
4301 | if (remains == 0 || zeroed != to_zero) | |
4302 | goto finished; | |
4303 | } | |
4304 | ||
4305 | n = vaddr + size - addr; | |
4306 | if (n > remains) | |
4307 | n = remains; | |
4308 | ||
4309 | if (flags & VMAP_RAM) | |
4310 | copied = vmap_ram_vread_iter(iter, addr, n, flags); | |
4311 | else if (!(vm && (vm->flags & (VM_IOREMAP | VM_SPARSE)))) | |
4312 | copied = aligned_vread_iter(iter, addr, n); | |
4313 | else /* IOREMAP | SPARSE area is treated as memory hole */ | |
4314 | copied = zero_iter(iter, n); | |
4315 | ||
4316 | addr += copied; | |
4317 | remains -= copied; | |
4318 | ||
4319 | if (copied != n) | |
4320 | goto finished; | |
4321 | ||
4322 | next_va: | |
4323 | next = va->va_end; | |
4324 | spin_unlock(&vn->busy.lock); | |
4325 | } while ((vn = find_vmap_area_exceed_addr_lock(next, &va))); | |
4326 | ||
4327 | finished_zero: | |
4328 | if (vn) | |
4329 | spin_unlock(&vn->busy.lock); | |
4330 | ||
4331 | /* zero-fill memory holes */ | |
4332 | return count - remains + zero_iter(iter, remains); | |
4333 | finished: | |
4334 | /* Nothing remains, or We couldn't copy/zero everything. */ | |
4335 | if (vn) | |
4336 | spin_unlock(&vn->busy.lock); | |
4337 | ||
4338 | return count - remains; | |
4339 | } | |
4340 | ||
4341 | /** | |
4342 | * remap_vmalloc_range_partial - map vmalloc pages to userspace | |
4343 | * @vma: vma to cover | |
4344 | * @uaddr: target user address to start at | |
4345 | * @kaddr: virtual address of vmalloc kernel memory | |
4346 | * @pgoff: offset from @kaddr to start at | |
4347 | * @size: size of map area | |
4348 | * | |
4349 | * Returns: 0 for success, -Exxx on failure | |
4350 | * | |
4351 | * This function checks that @kaddr is a valid vmalloc'ed area, | |
4352 | * and that it is big enough to cover the range starting at | |
4353 | * @uaddr in @vma. Will return failure if that criteria isn't | |
4354 | * met. | |
4355 | * | |
4356 | * Similar to remap_pfn_range() (see mm/memory.c) | |
4357 | */ | |
4358 | int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, | |
4359 | void *kaddr, unsigned long pgoff, | |
4360 | unsigned long size) | |
4361 | { | |
4362 | struct vm_struct *area; | |
4363 | unsigned long off; | |
4364 | unsigned long end_index; | |
4365 | ||
4366 | if (check_shl_overflow(pgoff, PAGE_SHIFT, &off)) | |
4367 | return -EINVAL; | |
4368 | ||
4369 | size = PAGE_ALIGN(size); | |
4370 | ||
4371 | if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr)) | |
4372 | return -EINVAL; | |
4373 | ||
4374 | area = find_vm_area(kaddr); | |
4375 | if (!area) | |
4376 | return -EINVAL; | |
4377 | ||
4378 | if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT))) | |
4379 | return -EINVAL; | |
4380 | ||
4381 | if (check_add_overflow(size, off, &end_index) || | |
4382 | end_index > get_vm_area_size(area)) | |
4383 | return -EINVAL; | |
4384 | kaddr += off; | |
4385 | ||
4386 | do { | |
4387 | struct page *page = vmalloc_to_page(kaddr); | |
4388 | int ret; | |
4389 | ||
4390 | ret = vm_insert_page(vma, uaddr, page); | |
4391 | if (ret) | |
4392 | return ret; | |
4393 | ||
4394 | uaddr += PAGE_SIZE; | |
4395 | kaddr += PAGE_SIZE; | |
4396 | size -= PAGE_SIZE; | |
4397 | } while (size > 0); | |
4398 | ||
4399 | vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); | |
4400 | ||
4401 | return 0; | |
4402 | } | |
4403 | ||
4404 | /** | |
4405 | * remap_vmalloc_range - map vmalloc pages to userspace | |
4406 | * @vma: vma to cover (map full range of vma) | |
4407 | * @addr: vmalloc memory | |
4408 | * @pgoff: number of pages into addr before first page to map | |
4409 | * | |
4410 | * Returns: 0 for success, -Exxx on failure | |
4411 | * | |
4412 | * This function checks that addr is a valid vmalloc'ed area, and | |
4413 | * that it is big enough to cover the vma. Will return failure if | |
4414 | * that criteria isn't met. | |
4415 | * | |
4416 | * Similar to remap_pfn_range() (see mm/memory.c) | |
4417 | */ | |
4418 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, | |
4419 | unsigned long pgoff) | |
4420 | { | |
4421 | return remap_vmalloc_range_partial(vma, vma->vm_start, | |
4422 | addr, pgoff, | |
4423 | vma->vm_end - vma->vm_start); | |
4424 | } | |
4425 | EXPORT_SYMBOL(remap_vmalloc_range); | |
4426 | ||
4427 | void free_vm_area(struct vm_struct *area) | |
4428 | { | |
4429 | struct vm_struct *ret; | |
4430 | ret = remove_vm_area(area->addr); | |
4431 | BUG_ON(ret != area); | |
4432 | kfree(area); | |
4433 | } | |
4434 | EXPORT_SYMBOL_GPL(free_vm_area); | |
4435 | ||
4436 | #ifdef CONFIG_SMP | |
4437 | static struct vmap_area *node_to_va(struct rb_node *n) | |
4438 | { | |
4439 | return rb_entry_safe(n, struct vmap_area, rb_node); | |
4440 | } | |
4441 | ||
4442 | /** | |
4443 | * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to | |
4444 | * @addr: target address | |
4445 | * | |
4446 | * Returns: vmap_area if it is found. If there is no such area | |
4447 | * the first highest(reverse order) vmap_area is returned | |
4448 | * i.e. va->va_start < addr && va->va_end < addr or NULL | |
4449 | * if there are no any areas before @addr. | |
4450 | */ | |
4451 | static struct vmap_area * | |
4452 | pvm_find_va_enclose_addr(unsigned long addr) | |
4453 | { | |
4454 | struct vmap_area *va, *tmp; | |
4455 | struct rb_node *n; | |
4456 | ||
4457 | n = free_vmap_area_root.rb_node; | |
4458 | va = NULL; | |
4459 | ||
4460 | while (n) { | |
4461 | tmp = rb_entry(n, struct vmap_area, rb_node); | |
4462 | if (tmp->va_start <= addr) { | |
4463 | va = tmp; | |
4464 | if (tmp->va_end >= addr) | |
4465 | break; | |
4466 | ||
4467 | n = n->rb_right; | |
4468 | } else { | |
4469 | n = n->rb_left; | |
4470 | } | |
4471 | } | |
4472 | ||
4473 | return va; | |
4474 | } | |
4475 | ||
4476 | /** | |
4477 | * pvm_determine_end_from_reverse - find the highest aligned address | |
4478 | * of free block below VMALLOC_END | |
4479 | * @va: | |
4480 | * in - the VA we start the search(reverse order); | |
4481 | * out - the VA with the highest aligned end address. | |
4482 | * @align: alignment for required highest address | |
4483 | * | |
4484 | * Returns: determined end address within vmap_area | |
4485 | */ | |
4486 | static unsigned long | |
4487 | pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align) | |
4488 | { | |
4489 | unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); | |
4490 | unsigned long addr; | |
4491 | ||
4492 | if (likely(*va)) { | |
4493 | list_for_each_entry_from_reverse((*va), | |
4494 | &free_vmap_area_list, list) { | |
4495 | addr = min((*va)->va_end & ~(align - 1), vmalloc_end); | |
4496 | if ((*va)->va_start < addr) | |
4497 | return addr; | |
4498 | } | |
4499 | } | |
4500 | ||
4501 | return 0; | |
4502 | } | |
4503 | ||
4504 | /** | |
4505 | * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator | |
4506 | * @offsets: array containing offset of each area | |
4507 | * @sizes: array containing size of each area | |
4508 | * @nr_vms: the number of areas to allocate | |
4509 | * @align: alignment, all entries in @offsets and @sizes must be aligned to this | |
4510 | * | |
4511 | * Returns: kmalloc'd vm_struct pointer array pointing to allocated | |
4512 | * vm_structs on success, %NULL on failure | |
4513 | * | |
4514 | * Percpu allocator wants to use congruent vm areas so that it can | |
4515 | * maintain the offsets among percpu areas. This function allocates | |
4516 | * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to | |
4517 | * be scattered pretty far, distance between two areas easily going up | |
4518 | * to gigabytes. To avoid interacting with regular vmallocs, these | |
4519 | * areas are allocated from top. | |
4520 | * | |
4521 | * Despite its complicated look, this allocator is rather simple. It | |
4522 | * does everything top-down and scans free blocks from the end looking | |
4523 | * for matching base. While scanning, if any of the areas do not fit the | |
4524 | * base address is pulled down to fit the area. Scanning is repeated till | |
4525 | * all the areas fit and then all necessary data structures are inserted | |
4526 | * and the result is returned. | |
4527 | */ | |
4528 | struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, | |
4529 | const size_t *sizes, int nr_vms, | |
4530 | size_t align) | |
4531 | { | |
4532 | const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); | |
4533 | const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); | |
4534 | struct vmap_area **vas, *va; | |
4535 | struct vm_struct **vms; | |
4536 | int area, area2, last_area, term_area; | |
4537 | unsigned long base, start, size, end, last_end, orig_start, orig_end; | |
4538 | bool purged = false; | |
4539 | ||
4540 | /* verify parameters and allocate data structures */ | |
4541 | BUG_ON(offset_in_page(align) || !is_power_of_2(align)); | |
4542 | for (last_area = 0, area = 0; area < nr_vms; area++) { | |
4543 | start = offsets[area]; | |
4544 | end = start + sizes[area]; | |
4545 | ||
4546 | /* is everything aligned properly? */ | |
4547 | BUG_ON(!IS_ALIGNED(offsets[area], align)); | |
4548 | BUG_ON(!IS_ALIGNED(sizes[area], align)); | |
4549 | ||
4550 | /* detect the area with the highest address */ | |
4551 | if (start > offsets[last_area]) | |
4552 | last_area = area; | |
4553 | ||
4554 | for (area2 = area + 1; area2 < nr_vms; area2++) { | |
4555 | unsigned long start2 = offsets[area2]; | |
4556 | unsigned long end2 = start2 + sizes[area2]; | |
4557 | ||
4558 | BUG_ON(start2 < end && start < end2); | |
4559 | } | |
4560 | } | |
4561 | last_end = offsets[last_area] + sizes[last_area]; | |
4562 | ||
4563 | if (vmalloc_end - vmalloc_start < last_end) { | |
4564 | WARN_ON(true); | |
4565 | return NULL; | |
4566 | } | |
4567 | ||
4568 | vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL); | |
4569 | vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL); | |
4570 | if (!vas || !vms) | |
4571 | goto err_free2; | |
4572 | ||
4573 | for (area = 0; area < nr_vms; area++) { | |
4574 | vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL); | |
4575 | vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL); | |
4576 | if (!vas[area] || !vms[area]) | |
4577 | goto err_free; | |
4578 | } | |
4579 | retry: | |
4580 | spin_lock(&free_vmap_area_lock); | |
4581 | ||
4582 | /* start scanning - we scan from the top, begin with the last area */ | |
4583 | area = term_area = last_area; | |
4584 | start = offsets[area]; | |
4585 | end = start + sizes[area]; | |
4586 | ||
4587 | va = pvm_find_va_enclose_addr(vmalloc_end); | |
4588 | base = pvm_determine_end_from_reverse(&va, align) - end; | |
4589 | ||
4590 | while (true) { | |
4591 | /* | |
4592 | * base might have underflowed, add last_end before | |
4593 | * comparing. | |
4594 | */ | |
4595 | if (base + last_end < vmalloc_start + last_end) | |
4596 | goto overflow; | |
4597 | ||
4598 | /* | |
4599 | * Fitting base has not been found. | |
4600 | */ | |
4601 | if (va == NULL) | |
4602 | goto overflow; | |
4603 | ||
4604 | /* | |
4605 | * If required width exceeds current VA block, move | |
4606 | * base downwards and then recheck. | |
4607 | */ | |
4608 | if (base + end > va->va_end) { | |
4609 | base = pvm_determine_end_from_reverse(&va, align) - end; | |
4610 | term_area = area; | |
4611 | continue; | |
4612 | } | |
4613 | ||
4614 | /* | |
4615 | * If this VA does not fit, move base downwards and recheck. | |
4616 | */ | |
4617 | if (base + start < va->va_start) { | |
4618 | va = node_to_va(rb_prev(&va->rb_node)); | |
4619 | base = pvm_determine_end_from_reverse(&va, align) - end; | |
4620 | term_area = area; | |
4621 | continue; | |
4622 | } | |
4623 | ||
4624 | /* | |
4625 | * This area fits, move on to the previous one. If | |
4626 | * the previous one is the terminal one, we're done. | |
4627 | */ | |
4628 | area = (area + nr_vms - 1) % nr_vms; | |
4629 | if (area == term_area) | |
4630 | break; | |
4631 | ||
4632 | start = offsets[area]; | |
4633 | end = start + sizes[area]; | |
4634 | va = pvm_find_va_enclose_addr(base + end); | |
4635 | } | |
4636 | ||
4637 | /* we've found a fitting base, insert all va's */ | |
4638 | for (area = 0; area < nr_vms; area++) { | |
4639 | int ret; | |
4640 | ||
4641 | start = base + offsets[area]; | |
4642 | size = sizes[area]; | |
4643 | ||
4644 | va = pvm_find_va_enclose_addr(start); | |
4645 | if (WARN_ON_ONCE(va == NULL)) | |
4646 | /* It is a BUG(), but trigger recovery instead. */ | |
4647 | goto recovery; | |
4648 | ||
4649 | ret = va_clip(&free_vmap_area_root, | |
4650 | &free_vmap_area_list, va, start, size); | |
4651 | if (WARN_ON_ONCE(unlikely(ret))) | |
4652 | /* It is a BUG(), but trigger recovery instead. */ | |
4653 | goto recovery; | |
4654 | ||
4655 | /* Allocated area. */ | |
4656 | va = vas[area]; | |
4657 | va->va_start = start; | |
4658 | va->va_end = start + size; | |
4659 | } | |
4660 | ||
4661 | spin_unlock(&free_vmap_area_lock); | |
4662 | ||
4663 | /* populate the kasan shadow space */ | |
4664 | for (area = 0; area < nr_vms; area++) { | |
4665 | if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area])) | |
4666 | goto err_free_shadow; | |
4667 | } | |
4668 | ||
4669 | /* insert all vm's */ | |
4670 | for (area = 0; area < nr_vms; area++) { | |
4671 | struct vmap_node *vn = addr_to_node(vas[area]->va_start); | |
4672 | ||
4673 | spin_lock(&vn->busy.lock); | |
4674 | insert_vmap_area(vas[area], &vn->busy.root, &vn->busy.head); | |
4675 | setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, | |
4676 | pcpu_get_vm_areas); | |
4677 | spin_unlock(&vn->busy.lock); | |
4678 | } | |
4679 | ||
4680 | /* | |
4681 | * Mark allocated areas as accessible. Do it now as a best-effort | |
4682 | * approach, as they can be mapped outside of vmalloc code. | |
4683 | * With hardware tag-based KASAN, marking is skipped for | |
4684 | * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). | |
4685 | */ | |
4686 | for (area = 0; area < nr_vms; area++) | |
4687 | vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, | |
4688 | vms[area]->size, KASAN_VMALLOC_PROT_NORMAL); | |
4689 | ||
4690 | kfree(vas); | |
4691 | return vms; | |
4692 | ||
4693 | recovery: | |
4694 | /* | |
4695 | * Remove previously allocated areas. There is no | |
4696 | * need in removing these areas from the busy tree, | |
4697 | * because they are inserted only on the final step | |
4698 | * and when pcpu_get_vm_areas() is success. | |
4699 | */ | |
4700 | while (area--) { | |
4701 | orig_start = vas[area]->va_start; | |
4702 | orig_end = vas[area]->va_end; | |
4703 | va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, | |
4704 | &free_vmap_area_list); | |
4705 | if (va) | |
4706 | kasan_release_vmalloc(orig_start, orig_end, | |
4707 | va->va_start, va->va_end); | |
4708 | vas[area] = NULL; | |
4709 | } | |
4710 | ||
4711 | overflow: | |
4712 | spin_unlock(&free_vmap_area_lock); | |
4713 | if (!purged) { | |
4714 | reclaim_and_purge_vmap_areas(); | |
4715 | purged = true; | |
4716 | ||
4717 | /* Before "retry", check if we recover. */ | |
4718 | for (area = 0; area < nr_vms; area++) { | |
4719 | if (vas[area]) | |
4720 | continue; | |
4721 | ||
4722 | vas[area] = kmem_cache_zalloc( | |
4723 | vmap_area_cachep, GFP_KERNEL); | |
4724 | if (!vas[area]) | |
4725 | goto err_free; | |
4726 | } | |
4727 | ||
4728 | goto retry; | |
4729 | } | |
4730 | ||
4731 | err_free: | |
4732 | for (area = 0; area < nr_vms; area++) { | |
4733 | if (vas[area]) | |
4734 | kmem_cache_free(vmap_area_cachep, vas[area]); | |
4735 | ||
4736 | kfree(vms[area]); | |
4737 | } | |
4738 | err_free2: | |
4739 | kfree(vas); | |
4740 | kfree(vms); | |
4741 | return NULL; | |
4742 | ||
4743 | err_free_shadow: | |
4744 | spin_lock(&free_vmap_area_lock); | |
4745 | /* | |
4746 | * We release all the vmalloc shadows, even the ones for regions that | |
4747 | * hadn't been successfully added. This relies on kasan_release_vmalloc | |
4748 | * being able to tolerate this case. | |
4749 | */ | |
4750 | for (area = 0; area < nr_vms; area++) { | |
4751 | orig_start = vas[area]->va_start; | |
4752 | orig_end = vas[area]->va_end; | |
4753 | va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, | |
4754 | &free_vmap_area_list); | |
4755 | if (va) | |
4756 | kasan_release_vmalloc(orig_start, orig_end, | |
4757 | va->va_start, va->va_end); | |
4758 | vas[area] = NULL; | |
4759 | kfree(vms[area]); | |
4760 | } | |
4761 | spin_unlock(&free_vmap_area_lock); | |
4762 | kfree(vas); | |
4763 | kfree(vms); | |
4764 | return NULL; | |
4765 | } | |
4766 | ||
4767 | /** | |
4768 | * pcpu_free_vm_areas - free vmalloc areas for percpu allocator | |
4769 | * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() | |
4770 | * @nr_vms: the number of allocated areas | |
4771 | * | |
4772 | * Free vm_structs and the array allocated by pcpu_get_vm_areas(). | |
4773 | */ | |
4774 | void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) | |
4775 | { | |
4776 | int i; | |
4777 | ||
4778 | for (i = 0; i < nr_vms; i++) | |
4779 | free_vm_area(vms[i]); | |
4780 | kfree(vms); | |
4781 | } | |
4782 | #endif /* CONFIG_SMP */ | |
4783 | ||
4784 | #ifdef CONFIG_PRINTK | |
4785 | bool vmalloc_dump_obj(void *object) | |
4786 | { | |
4787 | const void *caller; | |
4788 | struct vm_struct *vm; | |
4789 | struct vmap_area *va; | |
4790 | struct vmap_node *vn; | |
4791 | unsigned long addr; | |
4792 | unsigned int nr_pages; | |
4793 | ||
4794 | addr = PAGE_ALIGN((unsigned long) object); | |
4795 | vn = addr_to_node(addr); | |
4796 | ||
4797 | if (!spin_trylock(&vn->busy.lock)) | |
4798 | return false; | |
4799 | ||
4800 | va = __find_vmap_area(addr, &vn->busy.root); | |
4801 | if (!va || !va->vm) { | |
4802 | spin_unlock(&vn->busy.lock); | |
4803 | return false; | |
4804 | } | |
4805 | ||
4806 | vm = va->vm; | |
4807 | addr = (unsigned long) vm->addr; | |
4808 | caller = vm->caller; | |
4809 | nr_pages = vm->nr_pages; | |
4810 | spin_unlock(&vn->busy.lock); | |
4811 | ||
4812 | pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n", | |
4813 | nr_pages, addr, caller); | |
4814 | ||
4815 | return true; | |
4816 | } | |
4817 | #endif | |
4818 | ||
4819 | #ifdef CONFIG_PROC_FS | |
4820 | static void show_numa_info(struct seq_file *m, struct vm_struct *v) | |
4821 | { | |
4822 | if (IS_ENABLED(CONFIG_NUMA)) { | |
4823 | unsigned int nr, *counters = m->private; | |
4824 | unsigned int step = 1U << vm_area_page_order(v); | |
4825 | ||
4826 | if (!counters) | |
4827 | return; | |
4828 | ||
4829 | if (v->flags & VM_UNINITIALIZED) | |
4830 | return; | |
4831 | /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ | |
4832 | smp_rmb(); | |
4833 | ||
4834 | memset(counters, 0, nr_node_ids * sizeof(unsigned int)); | |
4835 | ||
4836 | for (nr = 0; nr < v->nr_pages; nr += step) | |
4837 | counters[page_to_nid(v->pages[nr])] += step; | |
4838 | for_each_node_state(nr, N_HIGH_MEMORY) | |
4839 | if (counters[nr]) | |
4840 | seq_printf(m, " N%u=%u", nr, counters[nr]); | |
4841 | } | |
4842 | } | |
4843 | ||
4844 | static void show_purge_info(struct seq_file *m) | |
4845 | { | |
4846 | struct vmap_node *vn; | |
4847 | struct vmap_area *va; | |
4848 | int i; | |
4849 | ||
4850 | for (i = 0; i < nr_vmap_nodes; i++) { | |
4851 | vn = &vmap_nodes[i]; | |
4852 | ||
4853 | spin_lock(&vn->lazy.lock); | |
4854 | list_for_each_entry(va, &vn->lazy.head, list) { | |
4855 | seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n", | |
4856 | (void *)va->va_start, (void *)va->va_end, | |
4857 | va->va_end - va->va_start); | |
4858 | } | |
4859 | spin_unlock(&vn->lazy.lock); | |
4860 | } | |
4861 | } | |
4862 | ||
4863 | static int vmalloc_info_show(struct seq_file *m, void *p) | |
4864 | { | |
4865 | struct vmap_node *vn; | |
4866 | struct vmap_area *va; | |
4867 | struct vm_struct *v; | |
4868 | int i; | |
4869 | ||
4870 | for (i = 0; i < nr_vmap_nodes; i++) { | |
4871 | vn = &vmap_nodes[i]; | |
4872 | ||
4873 | spin_lock(&vn->busy.lock); | |
4874 | list_for_each_entry(va, &vn->busy.head, list) { | |
4875 | if (!va->vm) { | |
4876 | if (va->flags & VMAP_RAM) | |
4877 | seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", | |
4878 | (void *)va->va_start, (void *)va->va_end, | |
4879 | va->va_end - va->va_start); | |
4880 | ||
4881 | continue; | |
4882 | } | |
4883 | ||
4884 | v = va->vm; | |
4885 | ||
4886 | seq_printf(m, "0x%pK-0x%pK %7ld", | |
4887 | v->addr, v->addr + v->size, v->size); | |
4888 | ||
4889 | if (v->caller) | |
4890 | seq_printf(m, " %pS", v->caller); | |
4891 | ||
4892 | if (v->nr_pages) | |
4893 | seq_printf(m, " pages=%d", v->nr_pages); | |
4894 | ||
4895 | if (v->phys_addr) | |
4896 | seq_printf(m, " phys=%pa", &v->phys_addr); | |
4897 | ||
4898 | if (v->flags & VM_IOREMAP) | |
4899 | seq_puts(m, " ioremap"); | |
4900 | ||
4901 | if (v->flags & VM_SPARSE) | |
4902 | seq_puts(m, " sparse"); | |
4903 | ||
4904 | if (v->flags & VM_ALLOC) | |
4905 | seq_puts(m, " vmalloc"); | |
4906 | ||
4907 | if (v->flags & VM_MAP) | |
4908 | seq_puts(m, " vmap"); | |
4909 | ||
4910 | if (v->flags & VM_USERMAP) | |
4911 | seq_puts(m, " user"); | |
4912 | ||
4913 | if (v->flags & VM_DMA_COHERENT) | |
4914 | seq_puts(m, " dma-coherent"); | |
4915 | ||
4916 | if (is_vmalloc_addr(v->pages)) | |
4917 | seq_puts(m, " vpages"); | |
4918 | ||
4919 | show_numa_info(m, v); | |
4920 | seq_putc(m, '\n'); | |
4921 | } | |
4922 | spin_unlock(&vn->busy.lock); | |
4923 | } | |
4924 | ||
4925 | /* | |
4926 | * As a final step, dump "unpurged" areas. | |
4927 | */ | |
4928 | show_purge_info(m); | |
4929 | return 0; | |
4930 | } | |
4931 | ||
4932 | static int __init proc_vmalloc_init(void) | |
4933 | { | |
4934 | void *priv_data = NULL; | |
4935 | ||
4936 | if (IS_ENABLED(CONFIG_NUMA)) | |
4937 | priv_data = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL); | |
4938 | ||
4939 | proc_create_single_data("vmallocinfo", | |
4940 | 0400, NULL, vmalloc_info_show, priv_data); | |
4941 | ||
4942 | return 0; | |
4943 | } | |
4944 | module_init(proc_vmalloc_init); | |
4945 | ||
4946 | #endif | |
4947 | ||
4948 | static void __init vmap_init_free_space(void) | |
4949 | { | |
4950 | unsigned long vmap_start = 1; | |
4951 | const unsigned long vmap_end = ULONG_MAX; | |
4952 | struct vmap_area *free; | |
4953 | struct vm_struct *busy; | |
4954 | ||
4955 | /* | |
4956 | * B F B B B F | |
4957 | * -|-----|.....|-----|-----|-----|.....|- | |
4958 | * | The KVA space | | |
4959 | * |<--------------------------------->| | |
4960 | */ | |
4961 | for (busy = vmlist; busy; busy = busy->next) { | |
4962 | if ((unsigned long) busy->addr - vmap_start > 0) { | |
4963 | free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); | |
4964 | if (!WARN_ON_ONCE(!free)) { | |
4965 | free->va_start = vmap_start; | |
4966 | free->va_end = (unsigned long) busy->addr; | |
4967 | ||
4968 | insert_vmap_area_augment(free, NULL, | |
4969 | &free_vmap_area_root, | |
4970 | &free_vmap_area_list); | |
4971 | } | |
4972 | } | |
4973 | ||
4974 | vmap_start = (unsigned long) busy->addr + busy->size; | |
4975 | } | |
4976 | ||
4977 | if (vmap_end - vmap_start > 0) { | |
4978 | free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); | |
4979 | if (!WARN_ON_ONCE(!free)) { | |
4980 | free->va_start = vmap_start; | |
4981 | free->va_end = vmap_end; | |
4982 | ||
4983 | insert_vmap_area_augment(free, NULL, | |
4984 | &free_vmap_area_root, | |
4985 | &free_vmap_area_list); | |
4986 | } | |
4987 | } | |
4988 | } | |
4989 | ||
4990 | static void vmap_init_nodes(void) | |
4991 | { | |
4992 | struct vmap_node *vn; | |
4993 | int i, n; | |
4994 | ||
4995 | #if BITS_PER_LONG == 64 | |
4996 | /* | |
4997 | * A high threshold of max nodes is fixed and bound to 128, | |
4998 | * thus a scale factor is 1 for systems where number of cores | |
4999 | * are less or equal to specified threshold. | |
5000 | * | |
5001 | * As for NUMA-aware notes. For bigger systems, for example | |
5002 | * NUMA with multi-sockets, where we can end-up with thousands | |
5003 | * of cores in total, a "sub-numa-clustering" should be added. | |
5004 | * | |
5005 | * In this case a NUMA domain is considered as a single entity | |
5006 | * with dedicated sub-nodes in it which describe one group or | |
5007 | * set of cores. Therefore a per-domain purging is supposed to | |
5008 | * be added as well as a per-domain balancing. | |
5009 | */ | |
5010 | n = clamp_t(unsigned int, num_possible_cpus(), 1, 128); | |
5011 | ||
5012 | if (n > 1) { | |
5013 | vn = kmalloc_array(n, sizeof(*vn), GFP_NOWAIT | __GFP_NOWARN); | |
5014 | if (vn) { | |
5015 | /* Node partition is 16 pages. */ | |
5016 | vmap_zone_size = (1 << 4) * PAGE_SIZE; | |
5017 | nr_vmap_nodes = n; | |
5018 | vmap_nodes = vn; | |
5019 | } else { | |
5020 | pr_err("Failed to allocate an array. Disable a node layer\n"); | |
5021 | } | |
5022 | } | |
5023 | #endif | |
5024 | ||
5025 | for (n = 0; n < nr_vmap_nodes; n++) { | |
5026 | vn = &vmap_nodes[n]; | |
5027 | vn->busy.root = RB_ROOT; | |
5028 | INIT_LIST_HEAD(&vn->busy.head); | |
5029 | spin_lock_init(&vn->busy.lock); | |
5030 | ||
5031 | vn->lazy.root = RB_ROOT; | |
5032 | INIT_LIST_HEAD(&vn->lazy.head); | |
5033 | spin_lock_init(&vn->lazy.lock); | |
5034 | ||
5035 | for (i = 0; i < MAX_VA_SIZE_PAGES; i++) { | |
5036 | INIT_LIST_HEAD(&vn->pool[i].head); | |
5037 | WRITE_ONCE(vn->pool[i].len, 0); | |
5038 | } | |
5039 | ||
5040 | spin_lock_init(&vn->pool_lock); | |
5041 | } | |
5042 | } | |
5043 | ||
5044 | static unsigned long | |
5045 | vmap_node_shrink_count(struct shrinker *shrink, struct shrink_control *sc) | |
5046 | { | |
5047 | unsigned long count; | |
5048 | struct vmap_node *vn; | |
5049 | int i, j; | |
5050 | ||
5051 | for (count = 0, i = 0; i < nr_vmap_nodes; i++) { | |
5052 | vn = &vmap_nodes[i]; | |
5053 | ||
5054 | for (j = 0; j < MAX_VA_SIZE_PAGES; j++) | |
5055 | count += READ_ONCE(vn->pool[j].len); | |
5056 | } | |
5057 | ||
5058 | return count ? count : SHRINK_EMPTY; | |
5059 | } | |
5060 | ||
5061 | static unsigned long | |
5062 | vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) | |
5063 | { | |
5064 | int i; | |
5065 | ||
5066 | for (i = 0; i < nr_vmap_nodes; i++) | |
5067 | decay_va_pool_node(&vmap_nodes[i], true); | |
5068 | ||
5069 | return SHRINK_STOP; | |
5070 | } | |
5071 | ||
5072 | void __init vmalloc_init(void) | |
5073 | { | |
5074 | struct shrinker *vmap_node_shrinker; | |
5075 | struct vmap_area *va; | |
5076 | struct vmap_node *vn; | |
5077 | struct vm_struct *tmp; | |
5078 | int i; | |
5079 | ||
5080 | /* | |
5081 | * Create the cache for vmap_area objects. | |
5082 | */ | |
5083 | vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC); | |
5084 | ||
5085 | for_each_possible_cpu(i) { | |
5086 | struct vmap_block_queue *vbq; | |
5087 | struct vfree_deferred *p; | |
5088 | ||
5089 | vbq = &per_cpu(vmap_block_queue, i); | |
5090 | spin_lock_init(&vbq->lock); | |
5091 | INIT_LIST_HEAD(&vbq->free); | |
5092 | p = &per_cpu(vfree_deferred, i); | |
5093 | init_llist_head(&p->list); | |
5094 | INIT_WORK(&p->wq, delayed_vfree_work); | |
5095 | xa_init(&vbq->vmap_blocks); | |
5096 | } | |
5097 | ||
5098 | /* | |
5099 | * Setup nodes before importing vmlist. | |
5100 | */ | |
5101 | vmap_init_nodes(); | |
5102 | ||
5103 | /* Import existing vmlist entries. */ | |
5104 | for (tmp = vmlist; tmp; tmp = tmp->next) { | |
5105 | va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); | |
5106 | if (WARN_ON_ONCE(!va)) | |
5107 | continue; | |
5108 | ||
5109 | va->va_start = (unsigned long)tmp->addr; | |
5110 | va->va_end = va->va_start + tmp->size; | |
5111 | va->vm = tmp; | |
5112 | ||
5113 | vn = addr_to_node(va->va_start); | |
5114 | insert_vmap_area(va, &vn->busy.root, &vn->busy.head); | |
5115 | } | |
5116 | ||
5117 | /* | |
5118 | * Now we can initialize a free vmap space. | |
5119 | */ | |
5120 | vmap_init_free_space(); | |
5121 | vmap_initialized = true; | |
5122 | ||
5123 | vmap_node_shrinker = shrinker_alloc(0, "vmap-node"); | |
5124 | if (!vmap_node_shrinker) { | |
5125 | pr_err("Failed to allocate vmap-node shrinker!\n"); | |
5126 | return; | |
5127 | } | |
5128 | ||
5129 | vmap_node_shrinker->count_objects = vmap_node_shrink_count; | |
5130 | vmap_node_shrinker->scan_objects = vmap_node_shrink_scan; | |
5131 | shrinker_register(vmap_node_shrinker); | |
5132 | } |