1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __MM_KASAN_KASAN_H
3 #define __MM_KASAN_KASAN_H
5 #include <linux/atomic.h>
6 #include <linux/kasan.h>
7 #include <linux/kasan-tags.h>
8 #include <linux/kfence.h>
9 #include <linux/stackdepot.h>
11 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
13 #include <linux/static_key.h>
15 DECLARE_STATIC_KEY_TRUE(kasan_flag_stacktrace);
17 static inline bool kasan_stack_collection_enabled(void)
19 return static_branch_unlikely(&kasan_flag_stacktrace);
22 #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
24 static inline bool kasan_stack_collection_enabled(void)
29 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
31 #ifdef CONFIG_KASAN_HW_TAGS
35 DECLARE_STATIC_KEY_TRUE(kasan_flag_vmalloc);
43 extern enum kasan_mode kasan_mode __ro_after_init;
45 extern unsigned long kasan_page_alloc_sample;
46 extern unsigned int kasan_page_alloc_sample_order;
47 DECLARE_PER_CPU(long, kasan_page_alloc_skip);
49 static inline bool kasan_vmalloc_enabled(void)
51 return static_branch_likely(&kasan_flag_vmalloc);
54 static inline bool kasan_async_fault_possible(void)
56 return kasan_mode == KASAN_MODE_ASYNC || kasan_mode == KASAN_MODE_ASYMM;
59 static inline bool kasan_sync_fault_possible(void)
61 return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM;
64 static inline bool kasan_sample_page_alloc(unsigned int order)
66 /* Fast-path for when sampling is disabled. */
67 if (kasan_page_alloc_sample == 1)
70 if (order < kasan_page_alloc_sample_order)
73 if (this_cpu_dec_return(kasan_page_alloc_skip) < 0) {
74 this_cpu_write(kasan_page_alloc_skip,
75 kasan_page_alloc_sample - 1);
82 #else /* CONFIG_KASAN_HW_TAGS */
84 static inline bool kasan_async_fault_possible(void)
89 static inline bool kasan_sync_fault_possible(void)
94 static inline bool kasan_sample_page_alloc(unsigned int order)
99 #endif /* CONFIG_KASAN_HW_TAGS */
101 #ifdef CONFIG_KASAN_GENERIC
103 /* Generic KASAN uses per-object metadata to store stack traces. */
104 static inline bool kasan_requires_meta(void)
107 * Technically, Generic KASAN always collects stack traces right now.
108 * However, let's use kasan_stack_collection_enabled() in case the
109 * kasan.stacktrace command-line argument is changed to affect
112 return kasan_stack_collection_enabled();
115 #else /* CONFIG_KASAN_GENERIC */
117 /* Tag-based KASAN modes do not use per-object metadata. */
118 static inline bool kasan_requires_meta(void)
123 #endif /* CONFIG_KASAN_GENERIC */
125 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
126 #define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
128 #include <asm/mte-kasan.h>
129 #define KASAN_GRANULE_SIZE MTE_GRANULE_SIZE
132 #define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1)
134 #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT)
136 #ifdef CONFIG_KASAN_GENERIC
137 #define KASAN_PAGE_FREE 0xFF /* freed page */
138 #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocation */
139 #define KASAN_SLAB_REDZONE 0xFC /* redzone for slab object */
140 #define KASAN_SLAB_FREE 0xFB /* freed slab object */
141 #define KASAN_VMALLOC_INVALID 0xF8 /* inaccessible space in vmap area */
143 #define KASAN_PAGE_FREE KASAN_TAG_INVALID
144 #define KASAN_PAGE_REDZONE KASAN_TAG_INVALID
145 #define KASAN_SLAB_REDZONE KASAN_TAG_INVALID
146 #define KASAN_SLAB_FREE KASAN_TAG_INVALID
147 #define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only used for SW_TAGS */
150 #ifdef CONFIG_KASAN_GENERIC
152 #define KASAN_SLAB_FREETRACK 0xFA /* freed slab object with free track */
153 #define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */
155 /* Stack redzone shadow values. Compiler ABI, do not change. */
156 #define KASAN_STACK_LEFT 0xF1
157 #define KASAN_STACK_MID 0xF2
158 #define KASAN_STACK_RIGHT 0xF3
159 #define KASAN_STACK_PARTIAL 0xF4
161 /* alloca redzone shadow values. */
162 #define KASAN_ALLOCA_LEFT 0xCA
163 #define KASAN_ALLOCA_RIGHT 0xCB
165 /* alloca redzone size. Compiler ABI, do not change. */
166 #define KASAN_ALLOCA_REDZONE_SIZE 32
168 /* Stack frame marker. Compiler ABI, do not change. */
169 #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3
171 /* Dummy value to avoid breaking randconfig/all*config builds. */
172 #ifndef KASAN_ABI_VERSION
173 #define KASAN_ABI_VERSION 1
176 #endif /* CONFIG_KASAN_GENERIC */
178 /* Metadata layout customization. */
179 #define META_BYTES_PER_BLOCK 1
180 #define META_BLOCKS_PER_ROW 16
181 #define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
182 #define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
183 #define META_ROWS_AROUND_ADDR 2
185 #define KASAN_STACK_DEPTH 64
189 depot_stack_handle_t stack;
192 enum kasan_report_type {
194 KASAN_REPORT_INVALID_FREE,
195 KASAN_REPORT_DOUBLE_FREE,
198 struct kasan_report_info {
199 /* Filled in by kasan_report_*(). */
200 enum kasan_report_type type;
201 const void *access_addr;
206 /* Filled in by the common reporting code. */
207 const void *first_bad_addr;
208 struct kmem_cache *cache;
212 /* Filled in by the mode-specific reporting code. */
213 const char *bug_type;
214 struct kasan_track alloc_track;
215 struct kasan_track free_track;
218 /* Do not change the struct layout: compiler ABI. */
219 struct kasan_source_location {
220 const char *filename;
225 /* Do not change the struct layout: compiler ABI. */
226 struct kasan_global {
227 const void *beg; /* Address of the beginning of the global variable. */
228 size_t size; /* Size of the global variable. */
229 size_t size_with_redzone; /* Size of the variable + size of the redzone. 32 bytes aligned. */
231 const void *module_name; /* Name of the module where the global variable is declared. */
232 unsigned long has_dynamic_init; /* This is needed for C++. */
233 #if KASAN_ABI_VERSION >= 4
234 struct kasan_source_location *location;
236 #if KASAN_ABI_VERSION >= 5
241 /* Structures for keeping alloc and free meta. */
243 #ifdef CONFIG_KASAN_GENERIC
245 struct kasan_alloc_meta {
246 struct kasan_track alloc_track;
247 /* Free track is stored in kasan_free_meta. */
248 depot_stack_handle_t aux_stack[2];
252 struct qlist_node *next;
256 * Free meta is stored either in the object itself or in the redzone after the
257 * object. In the former case, free meta offset is 0. In the latter case, the
258 * offset is between 0 and INT_MAX. INT_MAX marks that free meta is not present.
260 #define KASAN_NO_FREE_META INT_MAX
263 * Free meta is only used by Generic mode while the object is in quarantine.
264 * After that, slab allocator stores the freelist pointer in the object.
266 struct kasan_free_meta {
267 struct qlist_node quarantine_link;
268 struct kasan_track free_track;
271 #endif /* CONFIG_KASAN_GENERIC */
273 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
275 struct kasan_stack_ring_entry {
279 depot_stack_handle_t stack;
283 struct kasan_stack_ring {
287 struct kasan_stack_ring_entry *entries;
290 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
292 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
294 #ifndef kasan_shadow_to_mem
295 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
297 return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
298 << KASAN_SHADOW_SCALE_SHIFT);
302 #ifndef addr_has_metadata
303 static __always_inline bool addr_has_metadata(const void *addr)
305 return (kasan_reset_tag(addr) >=
306 kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
311 * kasan_check_range - Check memory region, and report if invalid access.
312 * @addr: the accessed address
313 * @size: the accessed size
314 * @write: true if access is a write access
315 * @ret_ip: return address
316 * @return: true if access was valid, false if invalid
318 bool kasan_check_range(const void *addr, size_t size, bool write,
319 unsigned long ret_ip);
321 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
323 static __always_inline bool addr_has_metadata(const void *addr)
325 return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
328 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
330 const void *kasan_find_first_bad_addr(const void *addr, size_t size);
331 size_t kasan_get_alloc_size(void *object, struct kmem_cache *cache);
332 void kasan_complete_mode_report_info(struct kasan_report_info *info);
333 void kasan_metadata_fetch_row(char *buffer, void *row);
335 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
336 void kasan_print_tags(u8 addr_tag, const void *addr);
338 static inline void kasan_print_tags(u8 addr_tag, const void *addr) { }
341 #if defined(CONFIG_KASAN_STACK)
342 void kasan_print_address_stack_frame(const void *addr);
344 static inline void kasan_print_address_stack_frame(const void *addr) { }
347 #ifdef CONFIG_KASAN_GENERIC
348 void kasan_print_aux_stacks(struct kmem_cache *cache, const void *object);
350 static inline void kasan_print_aux_stacks(struct kmem_cache *cache, const void *object) { }
353 bool kasan_report(const void *addr, size_t size,
354 bool is_write, unsigned long ip);
355 void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report_type type);
357 struct slab *kasan_addr_to_slab(const void *addr);
359 #ifdef CONFIG_KASAN_GENERIC
360 void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size);
361 void kasan_init_object_meta(struct kmem_cache *cache, const void *object);
362 struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
364 struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
367 static inline void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size) { }
368 static inline void kasan_init_object_meta(struct kmem_cache *cache, const void *object) { }
371 depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
372 void kasan_set_track(struct kasan_track *track, gfp_t flags);
373 void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);
374 void kasan_save_free_info(struct kmem_cache *cache, void *object);
376 #if defined(CONFIG_KASAN_GENERIC) && \
377 (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
378 bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
379 void kasan_quarantine_reduce(void);
380 void kasan_quarantine_remove_cache(struct kmem_cache *cache);
382 static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; }
383 static inline void kasan_quarantine_reduce(void) { }
384 static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { }
387 #ifndef arch_kasan_set_tag
388 static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
393 #ifndef arch_kasan_get_tag
394 #define arch_kasan_get_tag(addr) 0
397 #define set_tag(addr, tag) ((void *)arch_kasan_set_tag((addr), (tag)))
398 #define get_tag(addr) arch_kasan_get_tag(addr)
400 #ifdef CONFIG_KASAN_HW_TAGS
402 #define hw_enable_tag_checks_sync() arch_enable_tag_checks_sync()
403 #define hw_enable_tag_checks_async() arch_enable_tag_checks_async()
404 #define hw_enable_tag_checks_asymm() arch_enable_tag_checks_asymm()
405 #define hw_suppress_tag_checks_start() arch_suppress_tag_checks_start()
406 #define hw_suppress_tag_checks_stop() arch_suppress_tag_checks_stop()
407 #define hw_force_async_tag_fault() arch_force_async_tag_fault()
408 #define hw_get_random_tag() arch_get_random_tag()
409 #define hw_get_mem_tag(addr) arch_get_mem_tag(addr)
410 #define hw_set_mem_tag_range(addr, size, tag, init) \
411 arch_set_mem_tag_range((addr), (size), (tag), (init))
413 void kasan_enable_hw_tags(void);
415 #else /* CONFIG_KASAN_HW_TAGS */
417 static inline void kasan_enable_hw_tags(void) { }
419 #endif /* CONFIG_KASAN_HW_TAGS */
421 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
422 void __init kasan_init_tags(void);
423 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
425 #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
427 void kasan_force_async_fault(void);
429 #else /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
431 static inline void kasan_force_async_fault(void) { }
433 #endif /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
435 #ifdef CONFIG_KASAN_SW_TAGS
436 u8 kasan_random_tag(void);
437 #elif defined(CONFIG_KASAN_HW_TAGS)
438 static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); }
440 static inline u8 kasan_random_tag(void) { return 0; }
443 #ifdef CONFIG_KASAN_HW_TAGS
445 static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
447 addr = kasan_reset_tag(addr);
449 /* Skip KFENCE memory if called explicitly outside of sl*b. */
450 if (is_kfence_address(addr))
453 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
455 if (WARN_ON(size & KASAN_GRANULE_MASK))
458 hw_set_mem_tag_range((void *)addr, size, value, init);
461 static inline void kasan_unpoison(const void *addr, size_t size, bool init)
463 u8 tag = get_tag(addr);
465 addr = kasan_reset_tag(addr);
467 /* Skip KFENCE memory if called explicitly outside of sl*b. */
468 if (is_kfence_address(addr))
471 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
473 size = round_up(size, KASAN_GRANULE_SIZE);
475 hw_set_mem_tag_range((void *)addr, size, tag, init);
478 static inline bool kasan_byte_accessible(const void *addr)
480 u8 ptr_tag = get_tag(addr);
481 u8 mem_tag = hw_get_mem_tag((void *)addr);
483 return ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag;
486 #else /* CONFIG_KASAN_HW_TAGS */
489 * kasan_poison - mark the memory range as inaccessible
490 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
491 * @size - range size, must be aligned to KASAN_GRANULE_SIZE
492 * @value - value that's written to metadata for the range
493 * @init - whether to initialize the memory range (only for hardware tag-based)
495 * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
497 void kasan_poison(const void *addr, size_t size, u8 value, bool init);
500 * kasan_unpoison - mark the memory range as accessible
501 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
502 * @size - range size, can be unaligned
503 * @init - whether to initialize the memory range (only for hardware tag-based)
505 * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before
507 * For the generic mode, the last granule of the memory range gets partially
508 * unpoisoned based on the @size.
510 void kasan_unpoison(const void *addr, size_t size, bool init);
512 bool kasan_byte_accessible(const void *addr);
514 #endif /* CONFIG_KASAN_HW_TAGS */
516 #ifdef CONFIG_KASAN_GENERIC
519 * kasan_poison_last_granule - mark the last granule of the memory range as
521 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
524 * This function is only available for the generic mode, as it's the only mode
525 * that has partially poisoned memory granules.
527 void kasan_poison_last_granule(const void *address, size_t size);
529 #else /* CONFIG_KASAN_GENERIC */
531 static inline void kasan_poison_last_granule(const void *address, size_t size) { }
533 #endif /* CONFIG_KASAN_GENERIC */
535 #ifndef kasan_arch_is_ready
536 static inline bool kasan_arch_is_ready(void) { return true; }
537 #elif !defined(CONFIG_KASAN_GENERIC) || !defined(CONFIG_KASAN_OUTLINE)
538 #error kasan_arch_is_ready only works in KASAN generic outline mode!
541 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
543 void kasan_kunit_test_suite_start(void);
544 void kasan_kunit_test_suite_end(void);
546 #else /* CONFIG_KASAN_KUNIT_TEST */
548 static inline void kasan_kunit_test_suite_start(void) { }
549 static inline void kasan_kunit_test_suite_end(void) { }
551 #endif /* CONFIG_KASAN_KUNIT_TEST */
553 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST)
555 bool kasan_save_enable_multi_shot(void);
556 void kasan_restore_multi_shot(bool enabled);
561 * Exported functions for interfaces called from assembly or from generated
562 * code. Declared here to avoid warnings about missing declarations.
565 void __asan_register_globals(void *globals, ssize_t size);
566 void __asan_unregister_globals(void *globals, ssize_t size);
567 void __asan_handle_no_return(void);
568 void __asan_alloca_poison(void *, ssize_t size);
569 void __asan_allocas_unpoison(void *stack_top, ssize_t stack_bottom);
571 void __asan_load1(void *);
572 void __asan_store1(void *);
573 void __asan_load2(void *);
574 void __asan_store2(void *);
575 void __asan_load4(void *);
576 void __asan_store4(void *);
577 void __asan_load8(void *);
578 void __asan_store8(void *);
579 void __asan_load16(void *);
580 void __asan_store16(void *);
581 void __asan_loadN(void *, ssize_t size);
582 void __asan_storeN(void *, ssize_t size);
584 void __asan_load1_noabort(void *);
585 void __asan_store1_noabort(void *);
586 void __asan_load2_noabort(void *);
587 void __asan_store2_noabort(void *);
588 void __asan_load4_noabort(void *);
589 void __asan_store4_noabort(void *);
590 void __asan_load8_noabort(void *);
591 void __asan_store8_noabort(void *);
592 void __asan_load16_noabort(void *);
593 void __asan_store16_noabort(void *);
594 void __asan_loadN_noabort(void *, ssize_t size);
595 void __asan_storeN_noabort(void *, ssize_t size);
597 void __asan_report_load1_noabort(void *);
598 void __asan_report_store1_noabort(void *);
599 void __asan_report_load2_noabort(void *);
600 void __asan_report_store2_noabort(void *);
601 void __asan_report_load4_noabort(void *);
602 void __asan_report_store4_noabort(void *);
603 void __asan_report_load8_noabort(void *);
604 void __asan_report_store8_noabort(void *);
605 void __asan_report_load16_noabort(void *);
606 void __asan_report_store16_noabort(void *);
607 void __asan_report_load_n_noabort(void *, ssize_t size);
608 void __asan_report_store_n_noabort(void *, ssize_t size);
610 void __asan_set_shadow_00(const void *addr, ssize_t size);
611 void __asan_set_shadow_f1(const void *addr, ssize_t size);
612 void __asan_set_shadow_f2(const void *addr, ssize_t size);
613 void __asan_set_shadow_f3(const void *addr, ssize_t size);
614 void __asan_set_shadow_f5(const void *addr, ssize_t size);
615 void __asan_set_shadow_f8(const void *addr, ssize_t size);
617 void *__asan_memset(void *addr, int c, ssize_t len);
618 void *__asan_memmove(void *dest, const void *src, ssize_t len);
619 void *__asan_memcpy(void *dest, const void *src, ssize_t len);
621 void __hwasan_load1_noabort(void *);
622 void __hwasan_store1_noabort(void *);
623 void __hwasan_load2_noabort(void *);
624 void __hwasan_store2_noabort(void *);
625 void __hwasan_load4_noabort(void *);
626 void __hwasan_store4_noabort(void *);
627 void __hwasan_load8_noabort(void *);
628 void __hwasan_store8_noabort(void *);
629 void __hwasan_load16_noabort(void *);
630 void __hwasan_store16_noabort(void *);
631 void __hwasan_loadN_noabort(void *, ssize_t size);
632 void __hwasan_storeN_noabort(void *, ssize_t size);
634 void __hwasan_tag_memory(void *, u8 tag, ssize_t size);
636 void *__hwasan_memset(void *addr, int c, ssize_t len);
637 void *__hwasan_memmove(void *dest, const void *src, ssize_t len);
638 void *__hwasan_memcpy(void *dest, const void *src, ssize_t len);
640 void kasan_tag_mismatch(void *addr, unsigned long access_info,
641 unsigned long ret_ip);
643 #endif /* __MM_KASAN_KASAN_H */