Commit | Line | Data |
---|---|---|
0b24becc AR |
1 | /* |
2 | * This file contains shadow memory manipulation code. | |
3 | * | |
4 | * Copyright (c) 2014 Samsung Electronics Co., Ltd. | |
2baf9e89 | 5 | * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> |
0b24becc | 6 | * |
5d0926ef | 7 | * Some code borrowed from https://github.com/xairy/kasan-prototype by |
0b24becc AR |
8 | * Andrey Konovalov <adech.fo@gmail.com> |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 as | |
12 | * published by the Free Software Foundation. | |
13 | * | |
14 | */ | |
15 | ||
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
17 | #define DISABLE_BRANCH_PROFILING | |
18 | ||
19 | #include <linux/export.h> | |
cd11016e | 20 | #include <linux/interrupt.h> |
0b24becc | 21 | #include <linux/init.h> |
cd11016e | 22 | #include <linux/kasan.h> |
0b24becc | 23 | #include <linux/kernel.h> |
45937254 | 24 | #include <linux/kmemleak.h> |
e3ae1163 | 25 | #include <linux/linkage.h> |
0b24becc | 26 | #include <linux/memblock.h> |
786a8959 | 27 | #include <linux/memory.h> |
0b24becc | 28 | #include <linux/mm.h> |
bebf56a1 | 29 | #include <linux/module.h> |
0b24becc AR |
30 | #include <linux/printk.h> |
31 | #include <linux/sched.h> | |
68db0cf1 | 32 | #include <linux/sched/task_stack.h> |
0b24becc AR |
33 | #include <linux/slab.h> |
34 | #include <linux/stacktrace.h> | |
35 | #include <linux/string.h> | |
36 | #include <linux/types.h> | |
a5af5aa8 | 37 | #include <linux/vmalloc.h> |
9f7d416c | 38 | #include <linux/bug.h> |
0b24becc AR |
39 | |
40 | #include "kasan.h" | |
0316bec2 | 41 | #include "../slab.h" |
0b24becc | 42 | |
af8601ad IM |
43 | void kasan_enable_current(void) |
44 | { | |
45 | current->kasan_depth++; | |
46 | } | |
47 | ||
48 | void kasan_disable_current(void) | |
49 | { | |
50 | current->kasan_depth--; | |
51 | } | |
52 | ||
0b24becc AR |
53 | /* |
54 | * Poisons the shadow memory for 'size' bytes starting from 'addr'. | |
55 | * Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE. | |
56 | */ | |
57 | static void kasan_poison_shadow(const void *address, size_t size, u8 value) | |
58 | { | |
59 | void *shadow_start, *shadow_end; | |
60 | ||
61 | shadow_start = kasan_mem_to_shadow(address); | |
62 | shadow_end = kasan_mem_to_shadow(address + size); | |
63 | ||
64 | memset(shadow_start, value, shadow_end - shadow_start); | |
65 | } | |
66 | ||
67 | void kasan_unpoison_shadow(const void *address, size_t size) | |
68 | { | |
69 | kasan_poison_shadow(address, size, 0); | |
70 | ||
71 | if (size & KASAN_SHADOW_MASK) { | |
72 | u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); | |
73 | *shadow = size & KASAN_SHADOW_MASK; | |
74 | } | |
75 | } | |
76 | ||
9f7d416c | 77 | static void __kasan_unpoison_stack(struct task_struct *task, const void *sp) |
e3ae1163 MR |
78 | { |
79 | void *base = task_stack_page(task); | |
80 | size_t size = sp - base; | |
81 | ||
82 | kasan_unpoison_shadow(base, size); | |
83 | } | |
84 | ||
85 | /* Unpoison the entire stack for a task. */ | |
86 | void kasan_unpoison_task_stack(struct task_struct *task) | |
87 | { | |
88 | __kasan_unpoison_stack(task, task_stack_page(task) + THREAD_SIZE); | |
89 | } | |
90 | ||
91 | /* Unpoison the stack for the current task beyond a watermark sp value. */ | |
9f7d416c | 92 | asmlinkage void kasan_unpoison_task_stack_below(const void *watermark) |
e3ae1163 | 93 | { |
b53f40db JP |
94 | /* |
95 | * Calculate the task stack base address. Avoid using 'current' | |
96 | * because this function is called by early resume code which hasn't | |
97 | * yet set up the percpu register (%gs). | |
98 | */ | |
99 | void *base = (void *)((unsigned long)watermark & ~(THREAD_SIZE - 1)); | |
100 | ||
101 | kasan_unpoison_shadow(base, watermark - base); | |
9f7d416c DV |
102 | } |
103 | ||
104 | /* | |
105 | * Clear all poison for the region between the current SP and a provided | |
106 | * watermark value, as is sometimes required prior to hand-crafted asm function | |
107 | * returns in the middle of functions. | |
108 | */ | |
109 | void kasan_unpoison_stack_above_sp_to(const void *watermark) | |
110 | { | |
111 | const void *sp = __builtin_frame_address(0); | |
112 | size_t size = watermark - sp; | |
113 | ||
114 | if (WARN_ON(sp > watermark)) | |
115 | return; | |
116 | kasan_unpoison_shadow(sp, size); | |
e3ae1163 | 117 | } |
0b24becc AR |
118 | |
119 | /* | |
120 | * All functions below always inlined so compiler could | |
121 | * perform better optimizations in each of __asan_loadX/__assn_storeX | |
122 | * depending on memory access size X. | |
123 | */ | |
124 | ||
125 | static __always_inline bool memory_is_poisoned_1(unsigned long addr) | |
126 | { | |
127 | s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr); | |
128 | ||
129 | if (unlikely(shadow_value)) { | |
130 | s8 last_accessible_byte = addr & KASAN_SHADOW_MASK; | |
131 | return unlikely(last_accessible_byte >= shadow_value); | |
132 | } | |
133 | ||
134 | return false; | |
135 | } | |
136 | ||
137 | static __always_inline bool memory_is_poisoned_2(unsigned long addr) | |
138 | { | |
139 | u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); | |
140 | ||
141 | if (unlikely(*shadow_addr)) { | |
142 | if (memory_is_poisoned_1(addr + 1)) | |
143 | return true; | |
144 | ||
10f70262 XQ |
145 | /* |
146 | * If single shadow byte covers 2-byte access, we don't | |
147 | * need to do anything more. Otherwise, test the first | |
148 | * shadow byte. | |
149 | */ | |
0b24becc AR |
150 | if (likely(((addr + 1) & KASAN_SHADOW_MASK) != 0)) |
151 | return false; | |
152 | ||
153 | return unlikely(*(u8 *)shadow_addr); | |
154 | } | |
155 | ||
156 | return false; | |
157 | } | |
158 | ||
159 | static __always_inline bool memory_is_poisoned_4(unsigned long addr) | |
160 | { | |
161 | u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); | |
162 | ||
163 | if (unlikely(*shadow_addr)) { | |
164 | if (memory_is_poisoned_1(addr + 3)) | |
165 | return true; | |
166 | ||
10f70262 XQ |
167 | /* |
168 | * If single shadow byte covers 4-byte access, we don't | |
169 | * need to do anything more. Otherwise, test the first | |
170 | * shadow byte. | |
171 | */ | |
0b24becc AR |
172 | if (likely(((addr + 3) & KASAN_SHADOW_MASK) >= 3)) |
173 | return false; | |
174 | ||
175 | return unlikely(*(u8 *)shadow_addr); | |
176 | } | |
177 | ||
178 | return false; | |
179 | } | |
180 | ||
181 | static __always_inline bool memory_is_poisoned_8(unsigned long addr) | |
182 | { | |
183 | u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); | |
184 | ||
185 | if (unlikely(*shadow_addr)) { | |
186 | if (memory_is_poisoned_1(addr + 7)) | |
187 | return true; | |
188 | ||
10f70262 XQ |
189 | /* |
190 | * If single shadow byte covers 8-byte access, we don't | |
191 | * need to do anything more. Otherwise, test the first | |
192 | * shadow byte. | |
193 | */ | |
194 | if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) | |
0b24becc AR |
195 | return false; |
196 | ||
197 | return unlikely(*(u8 *)shadow_addr); | |
198 | } | |
199 | ||
200 | return false; | |
201 | } | |
202 | ||
203 | static __always_inline bool memory_is_poisoned_16(unsigned long addr) | |
204 | { | |
205 | u32 *shadow_addr = (u32 *)kasan_mem_to_shadow((void *)addr); | |
206 | ||
207 | if (unlikely(*shadow_addr)) { | |
208 | u16 shadow_first_bytes = *(u16 *)shadow_addr; | |
0b24becc AR |
209 | |
210 | if (unlikely(shadow_first_bytes)) | |
211 | return true; | |
212 | ||
10f70262 XQ |
213 | /* |
214 | * If two shadow bytes covers 16-byte access, we don't | |
215 | * need to do anything more. Otherwise, test the last | |
216 | * shadow byte. | |
217 | */ | |
218 | if (likely(IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) | |
0b24becc AR |
219 | return false; |
220 | ||
221 | return memory_is_poisoned_1(addr + 15); | |
222 | } | |
223 | ||
224 | return false; | |
225 | } | |
226 | ||
227 | static __always_inline unsigned long bytes_is_zero(const u8 *start, | |
228 | size_t size) | |
229 | { | |
230 | while (size) { | |
231 | if (unlikely(*start)) | |
232 | return (unsigned long)start; | |
233 | start++; | |
234 | size--; | |
235 | } | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
240 | static __always_inline unsigned long memory_is_zero(const void *start, | |
241 | const void *end) | |
242 | { | |
243 | unsigned int words; | |
244 | unsigned long ret; | |
245 | unsigned int prefix = (unsigned long)start % 8; | |
246 | ||
247 | if (end - start <= 16) | |
248 | return bytes_is_zero(start, end - start); | |
249 | ||
250 | if (prefix) { | |
251 | prefix = 8 - prefix; | |
252 | ret = bytes_is_zero(start, prefix); | |
253 | if (unlikely(ret)) | |
254 | return ret; | |
255 | start += prefix; | |
256 | } | |
257 | ||
258 | words = (end - start) / 8; | |
259 | while (words) { | |
260 | if (unlikely(*(u64 *)start)) | |
261 | return bytes_is_zero(start, 8); | |
262 | start += 8; | |
263 | words--; | |
264 | } | |
265 | ||
266 | return bytes_is_zero(start, (end - start) % 8); | |
267 | } | |
268 | ||
269 | static __always_inline bool memory_is_poisoned_n(unsigned long addr, | |
270 | size_t size) | |
271 | { | |
272 | unsigned long ret; | |
273 | ||
274 | ret = memory_is_zero(kasan_mem_to_shadow((void *)addr), | |
275 | kasan_mem_to_shadow((void *)addr + size - 1) + 1); | |
276 | ||
277 | if (unlikely(ret)) { | |
278 | unsigned long last_byte = addr + size - 1; | |
279 | s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); | |
280 | ||
281 | if (unlikely(ret != (unsigned long)last_shadow || | |
e0d57714 | 282 | ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) |
0b24becc AR |
283 | return true; |
284 | } | |
285 | return false; | |
286 | } | |
287 | ||
288 | static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size) | |
289 | { | |
290 | if (__builtin_constant_p(size)) { | |
291 | switch (size) { | |
292 | case 1: | |
293 | return memory_is_poisoned_1(addr); | |
294 | case 2: | |
295 | return memory_is_poisoned_2(addr); | |
296 | case 4: | |
297 | return memory_is_poisoned_4(addr); | |
298 | case 8: | |
299 | return memory_is_poisoned_8(addr); | |
300 | case 16: | |
301 | return memory_is_poisoned_16(addr); | |
302 | default: | |
303 | BUILD_BUG(); | |
304 | } | |
305 | } | |
306 | ||
307 | return memory_is_poisoned_n(addr, size); | |
308 | } | |
309 | ||
936bb4bb AR |
310 | static __always_inline void check_memory_region_inline(unsigned long addr, |
311 | size_t size, bool write, | |
312 | unsigned long ret_ip) | |
0b24becc | 313 | { |
0b24becc AR |
314 | if (unlikely(size == 0)) |
315 | return; | |
316 | ||
317 | if (unlikely((void *)addr < | |
318 | kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) { | |
936bb4bb | 319 | kasan_report(addr, size, write, ret_ip); |
0b24becc AR |
320 | return; |
321 | } | |
322 | ||
323 | if (likely(!memory_is_poisoned(addr, size))) | |
324 | return; | |
325 | ||
936bb4bb | 326 | kasan_report(addr, size, write, ret_ip); |
0b24becc AR |
327 | } |
328 | ||
936bb4bb AR |
329 | static void check_memory_region(unsigned long addr, |
330 | size_t size, bool write, | |
331 | unsigned long ret_ip) | |
332 | { | |
333 | check_memory_region_inline(addr, size, write, ret_ip); | |
334 | } | |
393f203f | 335 | |
64f8ebaf AR |
336 | void kasan_check_read(const void *p, unsigned int size) |
337 | { | |
338 | check_memory_region((unsigned long)p, size, false, _RET_IP_); | |
339 | } | |
340 | EXPORT_SYMBOL(kasan_check_read); | |
341 | ||
342 | void kasan_check_write(const void *p, unsigned int size) | |
343 | { | |
344 | check_memory_region((unsigned long)p, size, true, _RET_IP_); | |
345 | } | |
346 | EXPORT_SYMBOL(kasan_check_write); | |
347 | ||
393f203f AR |
348 | #undef memset |
349 | void *memset(void *addr, int c, size_t len) | |
350 | { | |
936bb4bb | 351 | check_memory_region((unsigned long)addr, len, true, _RET_IP_); |
393f203f AR |
352 | |
353 | return __memset(addr, c, len); | |
354 | } | |
355 | ||
356 | #undef memmove | |
357 | void *memmove(void *dest, const void *src, size_t len) | |
358 | { | |
936bb4bb AR |
359 | check_memory_region((unsigned long)src, len, false, _RET_IP_); |
360 | check_memory_region((unsigned long)dest, len, true, _RET_IP_); | |
393f203f AR |
361 | |
362 | return __memmove(dest, src, len); | |
363 | } | |
364 | ||
365 | #undef memcpy | |
366 | void *memcpy(void *dest, const void *src, size_t len) | |
367 | { | |
936bb4bb AR |
368 | check_memory_region((unsigned long)src, len, false, _RET_IP_); |
369 | check_memory_region((unsigned long)dest, len, true, _RET_IP_); | |
393f203f AR |
370 | |
371 | return __memcpy(dest, src, len); | |
372 | } | |
373 | ||
b8c73fc2 AR |
374 | void kasan_alloc_pages(struct page *page, unsigned int order) |
375 | { | |
376 | if (likely(!PageHighMem(page))) | |
377 | kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order); | |
378 | } | |
379 | ||
380 | void kasan_free_pages(struct page *page, unsigned int order) | |
381 | { | |
382 | if (likely(!PageHighMem(page))) | |
383 | kasan_poison_shadow(page_address(page), | |
384 | PAGE_SIZE << order, | |
385 | KASAN_FREE_PAGE); | |
386 | } | |
387 | ||
7ed2f9e6 AP |
388 | /* |
389 | * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. | |
390 | * For larger allocations larger redzones are used. | |
391 | */ | |
392 | static size_t optimal_redzone(size_t object_size) | |
393 | { | |
394 | int rz = | |
395 | object_size <= 64 - 16 ? 16 : | |
396 | object_size <= 128 - 32 ? 32 : | |
397 | object_size <= 512 - 64 ? 64 : | |
398 | object_size <= 4096 - 128 ? 128 : | |
399 | object_size <= (1 << 14) - 256 ? 256 : | |
400 | object_size <= (1 << 15) - 512 ? 512 : | |
401 | object_size <= (1 << 16) - 1024 ? 1024 : 2048; | |
402 | return rz; | |
403 | } | |
404 | ||
405 | void kasan_cache_create(struct kmem_cache *cache, size_t *size, | |
406 | unsigned long *flags) | |
407 | { | |
408 | int redzone_adjust; | |
80a9201a AP |
409 | int orig_size = *size; |
410 | ||
7ed2f9e6 AP |
411 | /* Add alloc meta. */ |
412 | cache->kasan_info.alloc_meta_offset = *size; | |
413 | *size += sizeof(struct kasan_alloc_meta); | |
414 | ||
415 | /* Add free meta. */ | |
416 | if (cache->flags & SLAB_DESTROY_BY_RCU || cache->ctor || | |
417 | cache->object_size < sizeof(struct kasan_free_meta)) { | |
418 | cache->kasan_info.free_meta_offset = *size; | |
419 | *size += sizeof(struct kasan_free_meta); | |
420 | } | |
421 | redzone_adjust = optimal_redzone(cache->object_size) - | |
422 | (*size - cache->object_size); | |
80a9201a | 423 | |
7ed2f9e6 AP |
424 | if (redzone_adjust > 0) |
425 | *size += redzone_adjust; | |
80a9201a AP |
426 | |
427 | *size = min(KMALLOC_MAX_SIZE, max(*size, cache->object_size + | |
428 | optimal_redzone(cache->object_size))); | |
429 | ||
430 | /* | |
431 | * If the metadata doesn't fit, don't enable KASAN at all. | |
432 | */ | |
433 | if (*size <= cache->kasan_info.alloc_meta_offset || | |
434 | *size <= cache->kasan_info.free_meta_offset) { | |
435 | cache->kasan_info.alloc_meta_offset = 0; | |
436 | cache->kasan_info.free_meta_offset = 0; | |
437 | *size = orig_size; | |
438 | return; | |
439 | } | |
440 | ||
441 | *flags |= SLAB_KASAN; | |
7ed2f9e6 | 442 | } |
7ed2f9e6 | 443 | |
55834c59 AP |
444 | void kasan_cache_shrink(struct kmem_cache *cache) |
445 | { | |
446 | quarantine_remove_cache(cache); | |
447 | } | |
448 | ||
f9fa1d91 | 449 | void kasan_cache_shutdown(struct kmem_cache *cache) |
55834c59 AP |
450 | { |
451 | quarantine_remove_cache(cache); | |
452 | } | |
453 | ||
80a9201a AP |
454 | size_t kasan_metadata_size(struct kmem_cache *cache) |
455 | { | |
456 | return (cache->kasan_info.alloc_meta_offset ? | |
457 | sizeof(struct kasan_alloc_meta) : 0) + | |
458 | (cache->kasan_info.free_meta_offset ? | |
459 | sizeof(struct kasan_free_meta) : 0); | |
460 | } | |
461 | ||
0316bec2 AR |
462 | void kasan_poison_slab(struct page *page) |
463 | { | |
464 | kasan_poison_shadow(page_address(page), | |
465 | PAGE_SIZE << compound_order(page), | |
466 | KASAN_KMALLOC_REDZONE); | |
467 | } | |
468 | ||
469 | void kasan_unpoison_object_data(struct kmem_cache *cache, void *object) | |
470 | { | |
471 | kasan_unpoison_shadow(object, cache->object_size); | |
472 | } | |
473 | ||
474 | void kasan_poison_object_data(struct kmem_cache *cache, void *object) | |
475 | { | |
476 | kasan_poison_shadow(object, | |
477 | round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE), | |
478 | KASAN_KMALLOC_REDZONE); | |
479 | } | |
480 | ||
cd11016e AP |
481 | static inline int in_irqentry_text(unsigned long ptr) |
482 | { | |
483 | return (ptr >= (unsigned long)&__irqentry_text_start && | |
484 | ptr < (unsigned long)&__irqentry_text_end) || | |
485 | (ptr >= (unsigned long)&__softirqentry_text_start && | |
486 | ptr < (unsigned long)&__softirqentry_text_end); | |
487 | } | |
488 | ||
489 | static inline void filter_irq_stacks(struct stack_trace *trace) | |
490 | { | |
491 | int i; | |
492 | ||
493 | if (!trace->nr_entries) | |
494 | return; | |
495 | for (i = 0; i < trace->nr_entries; i++) | |
496 | if (in_irqentry_text(trace->entries[i])) { | |
497 | /* Include the irqentry function into the stack. */ | |
498 | trace->nr_entries = i + 1; | |
499 | break; | |
500 | } | |
501 | } | |
502 | ||
503 | static inline depot_stack_handle_t save_stack(gfp_t flags) | |
504 | { | |
505 | unsigned long entries[KASAN_STACK_DEPTH]; | |
506 | struct stack_trace trace = { | |
507 | .nr_entries = 0, | |
508 | .entries = entries, | |
509 | .max_entries = KASAN_STACK_DEPTH, | |
510 | .skip = 0 | |
511 | }; | |
512 | ||
513 | save_stack_trace(&trace); | |
514 | filter_irq_stacks(&trace); | |
515 | if (trace.nr_entries != 0 && | |
516 | trace.entries[trace.nr_entries-1] == ULONG_MAX) | |
517 | trace.nr_entries--; | |
518 | ||
519 | return depot_save_stack(&trace, flags); | |
520 | } | |
521 | ||
522 | static inline void set_track(struct kasan_track *track, gfp_t flags) | |
7ed2f9e6 | 523 | { |
7ed2f9e6 | 524 | track->pid = current->pid; |
cd11016e | 525 | track->stack = save_stack(flags); |
7ed2f9e6 AP |
526 | } |
527 | ||
7ed2f9e6 AP |
528 | struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, |
529 | const void *object) | |
530 | { | |
cd11016e | 531 | BUILD_BUG_ON(sizeof(struct kasan_alloc_meta) > 32); |
7ed2f9e6 AP |
532 | return (void *)object + cache->kasan_info.alloc_meta_offset; |
533 | } | |
534 | ||
535 | struct kasan_free_meta *get_free_info(struct kmem_cache *cache, | |
536 | const void *object) | |
537 | { | |
cd11016e | 538 | BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32); |
7ed2f9e6 AP |
539 | return (void *)object + cache->kasan_info.free_meta_offset; |
540 | } | |
7ed2f9e6 | 541 | |
b3cbd9bf AR |
542 | void kasan_init_slab_obj(struct kmem_cache *cache, const void *object) |
543 | { | |
544 | struct kasan_alloc_meta *alloc_info; | |
545 | ||
546 | if (!(cache->flags & SLAB_KASAN)) | |
547 | return; | |
548 | ||
549 | alloc_info = get_alloc_info(cache, object); | |
550 | __memset(alloc_info, 0, sizeof(*alloc_info)); | |
551 | } | |
552 | ||
505f5dcb | 553 | void kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags) |
0316bec2 | 554 | { |
505f5dcb | 555 | kasan_kmalloc(cache, object, cache->object_size, flags); |
0316bec2 AR |
556 | } |
557 | ||
9b75a867 | 558 | static void kasan_poison_slab_free(struct kmem_cache *cache, void *object) |
0316bec2 AR |
559 | { |
560 | unsigned long size = cache->object_size; | |
561 | unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); | |
562 | ||
563 | /* RCU slabs could be legally used after free within the RCU period */ | |
564 | if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU)) | |
565 | return; | |
566 | ||
55834c59 AP |
567 | kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE); |
568 | } | |
569 | ||
570 | bool kasan_slab_free(struct kmem_cache *cache, void *object) | |
571 | { | |
b3cbd9bf AR |
572 | s8 shadow_byte; |
573 | ||
55834c59 AP |
574 | /* RCU slabs could be legally used after free within the RCU period */ |
575 | if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU)) | |
576 | return false; | |
577 | ||
b3cbd9bf AR |
578 | shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object)); |
579 | if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) { | |
5ab6d91a AK |
580 | kasan_report_double_free(cache, object, |
581 | __builtin_return_address(1)); | |
b3cbd9bf AR |
582 | return true; |
583 | } | |
80a9201a | 584 | |
b3cbd9bf | 585 | kasan_poison_slab_free(cache, object); |
55834c59 | 586 | |
b3cbd9bf AR |
587 | if (unlikely(!(cache->flags & SLAB_KASAN))) |
588 | return false; | |
589 | ||
590 | set_track(&get_alloc_info(cache, object)->free_track, GFP_NOWAIT); | |
591 | quarantine_put(get_free_info(cache, object), cache); | |
592 | return true; | |
0316bec2 AR |
593 | } |
594 | ||
505f5dcb AP |
595 | void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, |
596 | gfp_t flags) | |
0316bec2 AR |
597 | { |
598 | unsigned long redzone_start; | |
599 | unsigned long redzone_end; | |
600 | ||
4b3ec5a3 | 601 | if (gfpflags_allow_blocking(flags)) |
55834c59 AP |
602 | quarantine_reduce(); |
603 | ||
0316bec2 AR |
604 | if (unlikely(object == NULL)) |
605 | return; | |
606 | ||
607 | redzone_start = round_up((unsigned long)(object + size), | |
608 | KASAN_SHADOW_SCALE_SIZE); | |
609 | redzone_end = round_up((unsigned long)object + cache->object_size, | |
610 | KASAN_SHADOW_SCALE_SIZE); | |
611 | ||
612 | kasan_unpoison_shadow(object, size); | |
613 | kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start, | |
614 | KASAN_KMALLOC_REDZONE); | |
7ed2f9e6 | 615 | |
b3cbd9bf AR |
616 | if (cache->flags & SLAB_KASAN) |
617 | set_track(&get_alloc_info(cache, object)->alloc_track, flags); | |
0316bec2 AR |
618 | } |
619 | EXPORT_SYMBOL(kasan_kmalloc); | |
620 | ||
505f5dcb | 621 | void kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) |
0316bec2 AR |
622 | { |
623 | struct page *page; | |
624 | unsigned long redzone_start; | |
625 | unsigned long redzone_end; | |
626 | ||
4b3ec5a3 | 627 | if (gfpflags_allow_blocking(flags)) |
55834c59 AP |
628 | quarantine_reduce(); |
629 | ||
0316bec2 AR |
630 | if (unlikely(ptr == NULL)) |
631 | return; | |
632 | ||
633 | page = virt_to_page(ptr); | |
634 | redzone_start = round_up((unsigned long)(ptr + size), | |
635 | KASAN_SHADOW_SCALE_SIZE); | |
636 | redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page)); | |
637 | ||
638 | kasan_unpoison_shadow(ptr, size); | |
639 | kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start, | |
640 | KASAN_PAGE_REDZONE); | |
641 | } | |
642 | ||
505f5dcb | 643 | void kasan_krealloc(const void *object, size_t size, gfp_t flags) |
0316bec2 AR |
644 | { |
645 | struct page *page; | |
646 | ||
647 | if (unlikely(object == ZERO_SIZE_PTR)) | |
648 | return; | |
649 | ||
650 | page = virt_to_head_page(object); | |
651 | ||
652 | if (unlikely(!PageSlab(page))) | |
505f5dcb | 653 | kasan_kmalloc_large(object, size, flags); |
0316bec2 | 654 | else |
505f5dcb | 655 | kasan_kmalloc(page->slab_cache, object, size, flags); |
0316bec2 AR |
656 | } |
657 | ||
9b75a867 | 658 | void kasan_poison_kfree(void *ptr) |
92393615 AR |
659 | { |
660 | struct page *page; | |
661 | ||
662 | page = virt_to_head_page(ptr); | |
663 | ||
664 | if (unlikely(!PageSlab(page))) | |
665 | kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page), | |
666 | KASAN_FREE_PAGE); | |
667 | else | |
9b75a867 | 668 | kasan_poison_slab_free(page->slab_cache, ptr); |
92393615 AR |
669 | } |
670 | ||
0316bec2 AR |
671 | void kasan_kfree_large(const void *ptr) |
672 | { | |
673 | struct page *page = virt_to_page(ptr); | |
674 | ||
675 | kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page), | |
676 | KASAN_FREE_PAGE); | |
677 | } | |
678 | ||
bebf56a1 AR |
679 | int kasan_module_alloc(void *addr, size_t size) |
680 | { | |
681 | void *ret; | |
682 | size_t shadow_size; | |
683 | unsigned long shadow_start; | |
684 | ||
685 | shadow_start = (unsigned long)kasan_mem_to_shadow(addr); | |
686 | shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT, | |
687 | PAGE_SIZE); | |
688 | ||
689 | if (WARN_ON(!PAGE_ALIGNED(shadow_start))) | |
690 | return -EINVAL; | |
691 | ||
692 | ret = __vmalloc_node_range(shadow_size, 1, shadow_start, | |
693 | shadow_start + shadow_size, | |
19809c2d | 694 | GFP_KERNEL | __GFP_ZERO, |
bebf56a1 AR |
695 | PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE, |
696 | __builtin_return_address(0)); | |
a5af5aa8 AR |
697 | |
698 | if (ret) { | |
699 | find_vm_area(addr)->flags |= VM_KASAN; | |
45937254 | 700 | kmemleak_ignore(ret); |
a5af5aa8 AR |
701 | return 0; |
702 | } | |
703 | ||
704 | return -ENOMEM; | |
bebf56a1 AR |
705 | } |
706 | ||
a5af5aa8 | 707 | void kasan_free_shadow(const struct vm_struct *vm) |
bebf56a1 | 708 | { |
a5af5aa8 AR |
709 | if (vm->flags & VM_KASAN) |
710 | vfree(kasan_mem_to_shadow(vm->addr)); | |
bebf56a1 AR |
711 | } |
712 | ||
713 | static void register_global(struct kasan_global *global) | |
714 | { | |
715 | size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE); | |
716 | ||
717 | kasan_unpoison_shadow(global->beg, global->size); | |
718 | ||
719 | kasan_poison_shadow(global->beg + aligned_size, | |
720 | global->size_with_redzone - aligned_size, | |
721 | KASAN_GLOBAL_REDZONE); | |
722 | } | |
723 | ||
724 | void __asan_register_globals(struct kasan_global *globals, size_t size) | |
725 | { | |
726 | int i; | |
727 | ||
728 | for (i = 0; i < size; i++) | |
729 | register_global(&globals[i]); | |
730 | } | |
731 | EXPORT_SYMBOL(__asan_register_globals); | |
732 | ||
733 | void __asan_unregister_globals(struct kasan_global *globals, size_t size) | |
734 | { | |
735 | } | |
736 | EXPORT_SYMBOL(__asan_unregister_globals); | |
737 | ||
936bb4bb AR |
738 | #define DEFINE_ASAN_LOAD_STORE(size) \ |
739 | void __asan_load##size(unsigned long addr) \ | |
740 | { \ | |
741 | check_memory_region_inline(addr, size, false, _RET_IP_);\ | |
742 | } \ | |
743 | EXPORT_SYMBOL(__asan_load##size); \ | |
744 | __alias(__asan_load##size) \ | |
745 | void __asan_load##size##_noabort(unsigned long); \ | |
746 | EXPORT_SYMBOL(__asan_load##size##_noabort); \ | |
747 | void __asan_store##size(unsigned long addr) \ | |
748 | { \ | |
749 | check_memory_region_inline(addr, size, true, _RET_IP_); \ | |
750 | } \ | |
751 | EXPORT_SYMBOL(__asan_store##size); \ | |
752 | __alias(__asan_store##size) \ | |
753 | void __asan_store##size##_noabort(unsigned long); \ | |
0b24becc AR |
754 | EXPORT_SYMBOL(__asan_store##size##_noabort) |
755 | ||
756 | DEFINE_ASAN_LOAD_STORE(1); | |
757 | DEFINE_ASAN_LOAD_STORE(2); | |
758 | DEFINE_ASAN_LOAD_STORE(4); | |
759 | DEFINE_ASAN_LOAD_STORE(8); | |
760 | DEFINE_ASAN_LOAD_STORE(16); | |
761 | ||
762 | void __asan_loadN(unsigned long addr, size_t size) | |
763 | { | |
936bb4bb | 764 | check_memory_region(addr, size, false, _RET_IP_); |
0b24becc AR |
765 | } |
766 | EXPORT_SYMBOL(__asan_loadN); | |
767 | ||
768 | __alias(__asan_loadN) | |
769 | void __asan_loadN_noabort(unsigned long, size_t); | |
770 | EXPORT_SYMBOL(__asan_loadN_noabort); | |
771 | ||
772 | void __asan_storeN(unsigned long addr, size_t size) | |
773 | { | |
936bb4bb | 774 | check_memory_region(addr, size, true, _RET_IP_); |
0b24becc AR |
775 | } |
776 | EXPORT_SYMBOL(__asan_storeN); | |
777 | ||
778 | __alias(__asan_storeN) | |
779 | void __asan_storeN_noabort(unsigned long, size_t); | |
780 | EXPORT_SYMBOL(__asan_storeN_noabort); | |
781 | ||
782 | /* to shut up compiler complaints */ | |
783 | void __asan_handle_no_return(void) {} | |
784 | EXPORT_SYMBOL(__asan_handle_no_return); | |
786a8959 | 785 | |
828347f8 DV |
786 | /* Emitted by compiler to poison large objects when they go out of scope. */ |
787 | void __asan_poison_stack_memory(const void *addr, size_t size) | |
788 | { | |
789 | /* | |
790 | * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded | |
791 | * by redzones, so we simply round up size to simplify logic. | |
792 | */ | |
793 | kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE), | |
794 | KASAN_USE_AFTER_SCOPE); | |
795 | } | |
796 | EXPORT_SYMBOL(__asan_poison_stack_memory); | |
797 | ||
798 | /* Emitted by compiler to unpoison large objects when they go into scope. */ | |
799 | void __asan_unpoison_stack_memory(const void *addr, size_t size) | |
800 | { | |
801 | kasan_unpoison_shadow(addr, size); | |
802 | } | |
803 | EXPORT_SYMBOL(__asan_unpoison_stack_memory); | |
804 | ||
786a8959 AR |
805 | #ifdef CONFIG_MEMORY_HOTPLUG |
806 | static int kasan_mem_notifier(struct notifier_block *nb, | |
807 | unsigned long action, void *data) | |
808 | { | |
809 | return (action == MEM_GOING_ONLINE) ? NOTIFY_BAD : NOTIFY_OK; | |
810 | } | |
811 | ||
812 | static int __init kasan_memhotplug_init(void) | |
813 | { | |
91a4c272 SK |
814 | pr_info("WARNING: KASAN doesn't support memory hot-add\n"); |
815 | pr_info("Memory hot-add will be disabled\n"); | |
786a8959 AR |
816 | |
817 | hotplug_memory_notifier(kasan_mem_notifier, 0); | |
818 | ||
819 | return 0; | |
820 | } | |
821 | ||
822 | module_init(kasan_memhotplug_init); | |
823 | #endif |