1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * This file contains KASAN runtime code that manages shadow memory for
4 * generic and software tag-based KASAN modes.
5 *
6 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
7 * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
8 *
9 * Some code borrowed from https://github.com/xairy/kasan-prototype by
10 * Andrey Konovalov <andreyknvl@gmail.com>
11 */
12
13 #include <linux/init.h>
14 #include <linux/kasan.h>
15 #include <linux/kernel.h>
16 #include <linux/kfence.h>
17 #include <linux/kmemleak.h>
18 #include <linux/memory.h>
19 #include <linux/mm.h>
20 #include <linux/string.h>
21 #include <linux/types.h>
22 #include <linux/vmalloc.h>
23
24 #include <asm/cacheflush.h>
25 #include <asm/tlbflush.h>
26
27 #include "kasan.h"
28
__kasan_check_read(const volatile void * p,unsigned int size)29 bool __kasan_check_read(const volatile void *p, unsigned int size)
30 {
31 return kasan_check_range((void *)p, size, false, _RET_IP_);
32 }
33 EXPORT_SYMBOL(__kasan_check_read);
34
__kasan_check_write(const volatile void * p,unsigned int size)35 bool __kasan_check_write(const volatile void *p, unsigned int size)
36 {
37 return kasan_check_range((void *)p, size, true, _RET_IP_);
38 }
39 EXPORT_SYMBOL(__kasan_check_write);
40
41 #if !defined(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX) && !defined(CONFIG_GENERIC_ENTRY)
42 /*
43 * CONFIG_GENERIC_ENTRY relies on compiler emitted mem*() calls to not be
44 * instrumented. KASAN enabled toolchains should emit __asan_mem*() functions
45 * for the sites they want to instrument.
46 *
47 * If we have a compiler that can instrument meminstrinsics, never override
48 * these, so that non-instrumented files can safely consider them as builtins.
49 */
50 #undef memset
memset(void * addr,int c,size_t len)51 void *memset(void *addr, int c, size_t len)
52 {
53 if (!kasan_check_range(addr, len, true, _RET_IP_))
54 return NULL;
55
56 return __memset(addr, c, len);
57 }
58
59 #ifdef __HAVE_ARCH_MEMMOVE
60 #undef memmove
memmove(void * dest,const void * src,size_t len)61 void *memmove(void *dest, const void *src, size_t len)
62 {
63 if (!kasan_check_range(src, len, false, _RET_IP_) ||
64 !kasan_check_range(dest, len, true, _RET_IP_))
65 return NULL;
66
67 return __memmove(dest, src, len);
68 }
69 #endif
70
71 #undef memcpy
memcpy(void * dest,const void * src,size_t len)72 void *memcpy(void *dest, const void *src, size_t len)
73 {
74 if (!kasan_check_range(src, len, false, _RET_IP_) ||
75 !kasan_check_range(dest, len, true, _RET_IP_))
76 return NULL;
77
78 return __memcpy(dest, src, len);
79 }
80 #endif
81
__asan_memset(void * addr,int c,ssize_t len)82 void *__asan_memset(void *addr, int c, ssize_t len)
83 {
84 if (!kasan_check_range(addr, len, true, _RET_IP_))
85 return NULL;
86
87 return __memset(addr, c, len);
88 }
89 EXPORT_SYMBOL(__asan_memset);
90
91 #ifdef __HAVE_ARCH_MEMMOVE
__asan_memmove(void * dest,const void * src,ssize_t len)92 void *__asan_memmove(void *dest, const void *src, ssize_t len)
93 {
94 if (!kasan_check_range(src, len, false, _RET_IP_) ||
95 !kasan_check_range(dest, len, true, _RET_IP_))
96 return NULL;
97
98 return __memmove(dest, src, len);
99 }
100 EXPORT_SYMBOL(__asan_memmove);
101 #endif
102
__asan_memcpy(void * dest,const void * src,ssize_t len)103 void *__asan_memcpy(void *dest, const void *src, ssize_t len)
104 {
105 if (!kasan_check_range(src, len, false, _RET_IP_) ||
106 !kasan_check_range(dest, len, true, _RET_IP_))
107 return NULL;
108
109 return __memcpy(dest, src, len);
110 }
111 EXPORT_SYMBOL(__asan_memcpy);
112
113 #ifdef CONFIG_KASAN_SW_TAGS
114 void *__hwasan_memset(void *addr, int c, ssize_t len) __alias(__asan_memset);
115 EXPORT_SYMBOL(__hwasan_memset);
116 #ifdef __HAVE_ARCH_MEMMOVE
117 void *__hwasan_memmove(void *dest, const void *src, ssize_t len) __alias(__asan_memmove);
118 EXPORT_SYMBOL(__hwasan_memmove);
119 #endif
120 void *__hwasan_memcpy(void *dest, const void *src, ssize_t len) __alias(__asan_memcpy);
121 EXPORT_SYMBOL(__hwasan_memcpy);
122 #endif
123
kasan_poison(const void * addr,size_t size,u8 value,bool init)124 void kasan_poison(const void *addr, size_t size, u8 value, bool init)
125 {
126 void *shadow_start, *shadow_end;
127
128 if (!kasan_arch_is_ready())
129 return;
130
131 /*
132 * Perform shadow offset calculation based on untagged address, as
133 * some of the callers (e.g. kasan_poison_object_data) pass tagged
134 * addresses to this function.
135 */
136 addr = kasan_reset_tag(addr);
137
138 /* Skip KFENCE memory if called explicitly outside of sl*b. */
139 if (is_kfence_address(addr))
140 return;
141
142 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
143 return;
144 if (WARN_ON(size & KASAN_GRANULE_MASK))
145 return;
146
147 shadow_start = kasan_mem_to_shadow(addr);
148 shadow_end = kasan_mem_to_shadow(addr + size);
149
150 __memset(shadow_start, value, shadow_end - shadow_start);
151 }
152 EXPORT_SYMBOL(kasan_poison);
153
154 #ifdef CONFIG_KASAN_GENERIC
kasan_poison_last_granule(const void * addr,size_t size)155 void kasan_poison_last_granule(const void *addr, size_t size)
156 {
157 if (!kasan_arch_is_ready())
158 return;
159
160 if (size & KASAN_GRANULE_MASK) {
161 u8 *shadow = (u8 *)kasan_mem_to_shadow(addr + size);
162 *shadow = size & KASAN_GRANULE_MASK;
163 }
164 }
165 #endif
166
kasan_unpoison(const void * addr,size_t size,bool init)167 void kasan_unpoison(const void *addr, size_t size, bool init)
168 {
169 u8 tag = get_tag(addr);
170
171 /*
172 * Perform shadow offset calculation based on untagged address, as
173 * some of the callers (e.g. kasan_unpoison_object_data) pass tagged
174 * addresses to this function.
175 */
176 addr = kasan_reset_tag(addr);
177
178 /*
179 * Skip KFENCE memory if called explicitly outside of sl*b. Also note
180 * that calls to ksize(), where size is not a multiple of machine-word
181 * size, would otherwise poison the invalid portion of the word.
182 */
183 if (is_kfence_address(addr))
184 return;
185
186 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
187 return;
188
189 /* Unpoison all granules that cover the object. */
190 kasan_poison(addr, round_up(size, KASAN_GRANULE_SIZE), tag, false);
191
192 /* Partially poison the last granule for the generic mode. */
193 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
194 kasan_poison_last_granule(addr, size);
195 }
196
197 #ifdef CONFIG_MEMORY_HOTPLUG
shadow_mapped(unsigned long addr)198 static bool shadow_mapped(unsigned long addr)
199 {
200 pgd_t *pgd = pgd_offset_k(addr);
201 p4d_t *p4d;
202 pud_t *pud;
203 pmd_t *pmd;
204 pte_t *pte;
205
206 if (pgd_none(*pgd))
207 return false;
208 p4d = p4d_offset(pgd, addr);
209 if (p4d_none(*p4d))
210 return false;
211 pud = pud_offset(p4d, addr);
212 if (pud_none(*pud))
213 return false;
214
215 /*
216 * We can't use pud_large() or pud_huge(), the first one is
217 * arch-specific, the last one depends on HUGETLB_PAGE. So let's abuse
218 * pud_bad(), if pud is bad then it's bad because it's huge.
219 */
220 if (pud_bad(*pud))
221 return true;
222 pmd = pmd_offset(pud, addr);
223 if (pmd_none(*pmd))
224 return false;
225
226 if (pmd_bad(*pmd))
227 return true;
228 pte = pte_offset_kernel(pmd, addr);
229 return !pte_none(ptep_get(pte));
230 }
231
kasan_mem_notifier(struct notifier_block * nb,unsigned long action,void * data)232 static int __meminit kasan_mem_notifier(struct notifier_block *nb,
233 unsigned long action, void *data)
234 {
235 struct memory_notify *mem_data = data;
236 unsigned long nr_shadow_pages, start_kaddr, shadow_start;
237 unsigned long shadow_end, shadow_size;
238
239 nr_shadow_pages = mem_data->nr_pages >> KASAN_SHADOW_SCALE_SHIFT;
240 start_kaddr = (unsigned long)pfn_to_kaddr(mem_data->start_pfn);
241 shadow_start = (unsigned long)kasan_mem_to_shadow((void *)start_kaddr);
242 shadow_size = nr_shadow_pages << PAGE_SHIFT;
243 shadow_end = shadow_start + shadow_size;
244
245 if (WARN_ON(mem_data->nr_pages % KASAN_GRANULE_SIZE) ||
246 WARN_ON(start_kaddr % KASAN_MEMORY_PER_SHADOW_PAGE))
247 return NOTIFY_BAD;
248
249 switch (action) {
250 case MEM_GOING_ONLINE: {
251 void *ret;
252
253 /*
254 * If shadow is mapped already than it must have been mapped
255 * during the boot. This could happen if we onlining previously
256 * offlined memory.
257 */
258 if (shadow_mapped(shadow_start))
259 return NOTIFY_OK;
260
261 ret = __vmalloc_node_range(shadow_size, PAGE_SIZE, shadow_start,
262 shadow_end, GFP_KERNEL,
263 PAGE_KERNEL, VM_NO_GUARD,
264 pfn_to_nid(mem_data->start_pfn),
265 __builtin_return_address(0));
266 if (!ret)
267 return NOTIFY_BAD;
268
269 kmemleak_ignore(ret);
270 return NOTIFY_OK;
271 }
272 case MEM_CANCEL_ONLINE:
273 case MEM_OFFLINE: {
274 struct vm_struct *vm;
275
276 /*
277 * shadow_start was either mapped during boot by kasan_init()
278 * or during memory online by __vmalloc_node_range().
279 * In the latter case we can use vfree() to free shadow.
280 * Non-NULL result of the find_vm_area() will tell us if
281 * that was the second case.
282 *
283 * Currently it's not possible to free shadow mapped
284 * during boot by kasan_init(). It's because the code
285 * to do that hasn't been written yet. So we'll just
286 * leak the memory.
287 */
288 vm = find_vm_area((void *)shadow_start);
289 if (vm)
290 vfree((void *)shadow_start);
291 }
292 }
293
294 return NOTIFY_OK;
295 }
296
kasan_memhotplug_init(void)297 static int __init kasan_memhotplug_init(void)
298 {
299 hotplug_memory_notifier(kasan_mem_notifier, DEFAULT_CALLBACK_PRI);
300
301 return 0;
302 }
303
304 core_initcall(kasan_memhotplug_init);
305 #endif
306
307 #ifdef CONFIG_KASAN_VMALLOC
308
kasan_populate_early_vm_area_shadow(void * start,unsigned long size)309 void __init __weak kasan_populate_early_vm_area_shadow(void *start,
310 unsigned long size)
311 {
312 }
313
kasan_populate_vmalloc_pte(pte_t * ptep,unsigned long addr,void * unused)314 static int kasan_populate_vmalloc_pte(pte_t *ptep, unsigned long addr,
315 void *unused)
316 {
317 unsigned long page;
318 pte_t pte;
319
320 if (likely(!pte_none(ptep_get(ptep))))
321 return 0;
322
323 page = __get_free_page(GFP_KERNEL);
324 if (!page)
325 return -ENOMEM;
326
327 memset((void *)page, KASAN_VMALLOC_INVALID, PAGE_SIZE);
328 pte = pfn_pte(PFN_DOWN(__pa(page)), PAGE_KERNEL);
329
330 spin_lock(&init_mm.page_table_lock);
331 if (likely(pte_none(ptep_get(ptep)))) {
332 set_pte_at(&init_mm, addr, ptep, pte);
333 page = 0;
334 }
335 spin_unlock(&init_mm.page_table_lock);
336 if (page)
337 free_page(page);
338 return 0;
339 }
340
kasan_populate_vmalloc(unsigned long addr,unsigned long size)341 int kasan_populate_vmalloc(unsigned long addr, unsigned long size)
342 {
343 unsigned long shadow_start, shadow_end;
344 int ret;
345
346 if (!kasan_arch_is_ready())
347 return 0;
348
349 if (!is_vmalloc_or_module_addr((void *)addr))
350 return 0;
351
352 shadow_start = (unsigned long)kasan_mem_to_shadow((void *)addr);
353 shadow_end = (unsigned long)kasan_mem_to_shadow((void *)addr + size);
354
355 /*
356 * User Mode Linux maps enough shadow memory for all of virtual memory
357 * at boot, so doesn't need to allocate more on vmalloc, just clear it.
358 *
359 * The remaining CONFIG_UML checks in this file exist for the same
360 * reason.
361 */
362 if (IS_ENABLED(CONFIG_UML)) {
363 __memset((void *)shadow_start, KASAN_VMALLOC_INVALID, shadow_end - shadow_start);
364 return 0;
365 }
366
367 shadow_start = PAGE_ALIGN_DOWN(shadow_start);
368 shadow_end = PAGE_ALIGN(shadow_end);
369
370 ret = apply_to_page_range(&init_mm, shadow_start,
371 shadow_end - shadow_start,
372 kasan_populate_vmalloc_pte, NULL);
373 if (ret)
374 return ret;
375
376 flush_cache_vmap(shadow_start, shadow_end);
377
378 /*
379 * We need to be careful about inter-cpu effects here. Consider:
380 *
381 * CPU#0 CPU#1
382 * WRITE_ONCE(p, vmalloc(100)); while (x = READ_ONCE(p)) ;
383 * p[99] = 1;
384 *
385 * With compiler instrumentation, that ends up looking like this:
386 *
387 * CPU#0 CPU#1
388 * // vmalloc() allocates memory
389 * // let a = area->addr
390 * // we reach kasan_populate_vmalloc
391 * // and call kasan_unpoison:
392 * STORE shadow(a), unpoison_val
393 * ...
394 * STORE shadow(a+99), unpoison_val x = LOAD p
395 * // rest of vmalloc process <data dependency>
396 * STORE p, a LOAD shadow(x+99)
397 *
398 * If there is no barrier between the end of unpoisoning the shadow
399 * and the store of the result to p, the stores could be committed
400 * in a different order by CPU#0, and CPU#1 could erroneously observe
401 * poison in the shadow.
402 *
403 * We need some sort of barrier between the stores.
404 *
405 * In the vmalloc() case, this is provided by a smp_wmb() in
406 * clear_vm_uninitialized_flag(). In the per-cpu allocator and in
407 * get_vm_area() and friends, the caller gets shadow allocated but
408 * doesn't have any pages mapped into the virtual address space that
409 * has been reserved. Mapping those pages in will involve taking and
410 * releasing a page-table lock, which will provide the barrier.
411 */
412
413 return 0;
414 }
415
kasan_depopulate_vmalloc_pte(pte_t * ptep,unsigned long addr,void * unused)416 static int kasan_depopulate_vmalloc_pte(pte_t *ptep, unsigned long addr,
417 void *unused)
418 {
419 unsigned long page;
420
421 page = (unsigned long)__va(pte_pfn(ptep_get(ptep)) << PAGE_SHIFT);
422
423 spin_lock(&init_mm.page_table_lock);
424
425 if (likely(!pte_none(ptep_get(ptep)))) {
426 pte_clear(&init_mm, addr, ptep);
427 free_page(page);
428 }
429 spin_unlock(&init_mm.page_table_lock);
430
431 return 0;
432 }
433
434 /*
435 * Release the backing for the vmalloc region [start, end), which
436 * lies within the free region [free_region_start, free_region_end).
437 *
438 * This can be run lazily, long after the region was freed. It runs
439 * under vmap_area_lock, so it's not safe to interact with the vmalloc/vmap
440 * infrastructure.
441 *
442 * How does this work?
443 * -------------------
444 *
445 * We have a region that is page aligned, labeled as A.
446 * That might not map onto the shadow in a way that is page-aligned:
447 *
448 * start end
449 * v v
450 * |????????|????????|AAAAAAAA|AA....AA|AAAAAAAA|????????| < vmalloc
451 * -------- -------- -------- -------- --------
452 * | | | | |
453 * | | | /-------/ |
454 * \-------\|/------/ |/---------------/
455 * ||| ||
456 * |??AAAAAA|AAAAAAAA|AA??????| < shadow
457 * (1) (2) (3)
458 *
459 * First we align the start upwards and the end downwards, so that the
460 * shadow of the region aligns with shadow page boundaries. In the
461 * example, this gives us the shadow page (2). This is the shadow entirely
462 * covered by this allocation.
463 *
464 * Then we have the tricky bits. We want to know if we can free the
465 * partially covered shadow pages - (1) and (3) in the example. For this,
466 * we are given the start and end of the free region that contains this
467 * allocation. Extending our previous example, we could have:
468 *
469 * free_region_start free_region_end
470 * | start end |
471 * v v v v
472 * |FFFFFFFF|FFFFFFFF|AAAAAAAA|AA....AA|AAAAAAAA|FFFFFFFF| < vmalloc
473 * -------- -------- -------- -------- --------
474 * | | | | |
475 * | | | /-------/ |
476 * \-------\|/------/ |/---------------/
477 * ||| ||
478 * |FFAAAAAA|AAAAAAAA|AAF?????| < shadow
479 * (1) (2) (3)
480 *
481 * Once again, we align the start of the free region up, and the end of
482 * the free region down so that the shadow is page aligned. So we can free
483 * page (1) - we know no allocation currently uses anything in that page,
484 * because all of it is in the vmalloc free region. But we cannot free
485 * page (3), because we can't be sure that the rest of it is unused.
486 *
487 * We only consider pages that contain part of the original region for
488 * freeing: we don't try to free other pages from the free region or we'd
489 * end up trying to free huge chunks of virtual address space.
490 *
491 * Concurrency
492 * -----------
493 *
494 * How do we know that we're not freeing a page that is simultaneously
495 * being used for a fresh allocation in kasan_populate_vmalloc(_pte)?
496 *
497 * We _can_ have kasan_release_vmalloc and kasan_populate_vmalloc running
498 * at the same time. While we run under free_vmap_area_lock, the population
499 * code does not.
500 *
501 * free_vmap_area_lock instead operates to ensure that the larger range
502 * [free_region_start, free_region_end) is safe: because __alloc_vmap_area and
503 * the per-cpu region-finding algorithm both run under free_vmap_area_lock,
504 * no space identified as free will become used while we are running. This
505 * means that so long as we are careful with alignment and only free shadow
506 * pages entirely covered by the free region, we will not run in to any
507 * trouble - any simultaneous allocations will be for disjoint regions.
508 */
kasan_release_vmalloc(unsigned long start,unsigned long end,unsigned long free_region_start,unsigned long free_region_end)509 void kasan_release_vmalloc(unsigned long start, unsigned long end,
510 unsigned long free_region_start,
511 unsigned long free_region_end)
512 {
513 void *shadow_start, *shadow_end;
514 unsigned long region_start, region_end;
515 unsigned long size;
516
517 if (!kasan_arch_is_ready())
518 return;
519
520 region_start = ALIGN(start, KASAN_MEMORY_PER_SHADOW_PAGE);
521 region_end = ALIGN_DOWN(end, KASAN_MEMORY_PER_SHADOW_PAGE);
522
523 free_region_start = ALIGN(free_region_start, KASAN_MEMORY_PER_SHADOW_PAGE);
524
525 if (start != region_start &&
526 free_region_start < region_start)
527 region_start -= KASAN_MEMORY_PER_SHADOW_PAGE;
528
529 free_region_end = ALIGN_DOWN(free_region_end, KASAN_MEMORY_PER_SHADOW_PAGE);
530
531 if (end != region_end &&
532 free_region_end > region_end)
533 region_end += KASAN_MEMORY_PER_SHADOW_PAGE;
534
535 shadow_start = kasan_mem_to_shadow((void *)region_start);
536 shadow_end = kasan_mem_to_shadow((void *)region_end);
537
538 if (shadow_end > shadow_start) {
539 size = shadow_end - shadow_start;
540 if (IS_ENABLED(CONFIG_UML)) {
541 __memset(shadow_start, KASAN_SHADOW_INIT, shadow_end - shadow_start);
542 return;
543 }
544 apply_to_existing_page_range(&init_mm,
545 (unsigned long)shadow_start,
546 size, kasan_depopulate_vmalloc_pte,
547 NULL);
548 flush_tlb_kernel_range((unsigned long)shadow_start,
549 (unsigned long)shadow_end);
550 }
551 }
552
__kasan_unpoison_vmalloc(const void * start,unsigned long size,kasan_vmalloc_flags_t flags)553 void *__kasan_unpoison_vmalloc(const void *start, unsigned long size,
554 kasan_vmalloc_flags_t flags)
555 {
556 /*
557 * Software KASAN modes unpoison both VM_ALLOC and non-VM_ALLOC
558 * mappings, so the KASAN_VMALLOC_VM_ALLOC flag is ignored.
559 * Software KASAN modes can't optimize zeroing memory by combining it
560 * with setting memory tags, so the KASAN_VMALLOC_INIT flag is ignored.
561 */
562
563 if (!kasan_arch_is_ready())
564 return (void *)start;
565
566 if (!is_vmalloc_or_module_addr(start))
567 return (void *)start;
568
569 /*
570 * Don't tag executable memory with the tag-based mode.
571 * The kernel doesn't tolerate having the PC register tagged.
572 */
573 if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) &&
574 !(flags & KASAN_VMALLOC_PROT_NORMAL))
575 return (void *)start;
576
577 start = set_tag(start, kasan_random_tag());
578 kasan_unpoison(start, size, false);
579 return (void *)start;
580 }
581
582 /*
583 * Poison the shadow for a vmalloc region. Called as part of the
584 * freeing process at the time the region is freed.
585 */
__kasan_poison_vmalloc(const void * start,unsigned long size)586 void __kasan_poison_vmalloc(const void *start, unsigned long size)
587 {
588 if (!kasan_arch_is_ready())
589 return;
590
591 if (!is_vmalloc_or_module_addr(start))
592 return;
593
594 size = round_up(size, KASAN_GRANULE_SIZE);
595 kasan_poison(start, size, KASAN_VMALLOC_INVALID, false);
596 }
597
598 #else /* CONFIG_KASAN_VMALLOC */
599
kasan_alloc_module_shadow(void * addr,size_t size,gfp_t gfp_mask)600 int kasan_alloc_module_shadow(void *addr, size_t size, gfp_t gfp_mask)
601 {
602 void *ret;
603 size_t scaled_size;
604 size_t shadow_size;
605 unsigned long shadow_start;
606
607 shadow_start = (unsigned long)kasan_mem_to_shadow(addr);
608 scaled_size = (size + KASAN_GRANULE_SIZE - 1) >>
609 KASAN_SHADOW_SCALE_SHIFT;
610 shadow_size = round_up(scaled_size, PAGE_SIZE);
611
612 if (WARN_ON(!PAGE_ALIGNED(shadow_start)))
613 return -EINVAL;
614
615 if (IS_ENABLED(CONFIG_UML)) {
616 __memset((void *)shadow_start, KASAN_SHADOW_INIT, shadow_size);
617 return 0;
618 }
619
620 ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
621 shadow_start + shadow_size,
622 GFP_KERNEL,
623 PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
624 __builtin_return_address(0));
625
626 if (ret) {
627 struct vm_struct *vm = find_vm_area(addr);
628 __memset(ret, KASAN_SHADOW_INIT, shadow_size);
629 vm->flags |= VM_KASAN;
630 kmemleak_ignore(ret);
631
632 if (vm->flags & VM_DEFER_KMEMLEAK)
633 kmemleak_vmalloc(vm, size, gfp_mask);
634
635 return 0;
636 }
637
638 return -ENOMEM;
639 }
640
kasan_free_module_shadow(const struct vm_struct * vm)641 void kasan_free_module_shadow(const struct vm_struct *vm)
642 {
643 if (IS_ENABLED(CONFIG_UML))
644 return;
645
646 if (vm->flags & VM_KASAN)
647 vfree(kasan_mem_to_shadow(vm->addr));
648 }
649
650 #endif
651