1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __MM_KASAN_KASAN_H
3#define __MM_KASAN_KASAN_H
4
5#include <linux/kasan.h>
6#include <linux/kasan-tags.h>
7#include <linux/kfence.h>
8#include <linux/stackdepot.h>
9
10#ifdef CONFIG_KASAN_HW_TAGS
11
12#include <linux/static_key.h>
13#include "../slab.h"
14
15DECLARE_STATIC_KEY_TRUE(kasan_flag_vmalloc);
16DECLARE_STATIC_KEY_TRUE(kasan_flag_stacktrace);
17
18enum kasan_mode {
19 KASAN_MODE_SYNC,
20 KASAN_MODE_ASYNC,
21 KASAN_MODE_ASYMM,
22};
23
24extern enum kasan_mode kasan_mode __ro_after_init;
25
26static inline bool kasan_vmalloc_enabled(void)
27{
28 return static_branch_likely(&kasan_flag_vmalloc);
29}
30
31static inline bool kasan_stack_collection_enabled(void)
32{
33 return static_branch_unlikely(&kasan_flag_stacktrace);
34}
35
36static inline bool kasan_async_fault_possible(void)
37{
38 return kasan_mode == KASAN_MODE_ASYNC || kasan_mode == KASAN_MODE_ASYMM;
39}
40
41static inline bool kasan_sync_fault_possible(void)
42{
43 return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM;
44}
45
46#else
47
48static inline bool kasan_stack_collection_enabled(void)
49{
50 return true;
51}
52
53static inline bool kasan_async_fault_possible(void)
54{
55 return false;
56}
57
58static inline bool kasan_sync_fault_possible(void)
59{
60 return true;
61}
62
63#endif
64
65#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
66#define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
67#else
68#include <asm/mte-kasan.h>
69#define KASAN_GRANULE_SIZE MTE_GRANULE_SIZE
70#endif
71
72#define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1)
73
74#define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT)
75
76#ifdef CONFIG_KASAN_GENERIC
77#define KASAN_PAGE_FREE 0xFF /* freed page */
78#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocation */
79#define KASAN_SLAB_REDZONE 0xFC /* redzone for slab object */
80#define KASAN_SLAB_FREE 0xFB /* freed slab object */
81#define KASAN_VMALLOC_INVALID 0xF8 /* inaccessible space in vmap area */
82#else
83#define KASAN_PAGE_FREE KASAN_TAG_INVALID
84#define KASAN_PAGE_REDZONE KASAN_TAG_INVALID
85#define KASAN_SLAB_REDZONE KASAN_TAG_INVALID
86#define KASAN_SLAB_FREE KASAN_TAG_INVALID
87#define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only used for SW_TAGS */
88#endif
89
90#ifdef CONFIG_KASAN_GENERIC
91
92#define KASAN_SLAB_FREETRACK 0xFA /* freed slab object with free track */
93#define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */
94
95/* Stack redzone shadow values. Compiler ABI, do not change. */
96#define KASAN_STACK_LEFT 0xF1
97#define KASAN_STACK_MID 0xF2
98#define KASAN_STACK_RIGHT 0xF3
99#define KASAN_STACK_PARTIAL 0xF4
100
101/* alloca redzone shadow values. */
102#define KASAN_ALLOCA_LEFT 0xCA
103#define KASAN_ALLOCA_RIGHT 0xCB
104
105/* alloca redzone size. Compiler ABI, do not change. */
106#define KASAN_ALLOCA_REDZONE_SIZE 32
107
108/* Stack frame marker. Compiler ABI, do not change. */
109#define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3
110
111/* Dummy value to avoid breaking randconfig/all*config builds. */
112#ifndef KASAN_ABI_VERSION
113#define KASAN_ABI_VERSION 1
114#endif
115
116#endif /* CONFIG_KASAN_GENERIC */
117
118/* Metadata layout customization. */
119#define META_BYTES_PER_BLOCK 1
120#define META_BLOCKS_PER_ROW 16
121#define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
122#define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
123#define META_ROWS_AROUND_ADDR 2
124
125enum kasan_report_type {
126 KASAN_REPORT_ACCESS,
127 KASAN_REPORT_INVALID_FREE,
128 KASAN_REPORT_DOUBLE_FREE,
129};
130
131struct kasan_report_info {
132 enum kasan_report_type type;
133 void *access_addr;
134 void *first_bad_addr;
135 size_t access_size;
136 bool is_write;
137 unsigned long ip;
138};
139
140/* Do not change the struct layout: compiler ABI. */
141struct kasan_source_location {
142 const char *filename;
143 int line_no;
144 int column_no;
145};
146
147/* Do not change the struct layout: compiler ABI. */
148struct kasan_global {
149 const void *beg; /* Address of the beginning of the global variable. */
150 size_t size; /* Size of the global variable. */
151 size_t size_with_redzone; /* Size of the variable + size of the redzone. 32 bytes aligned. */
152 const void *name;
153 const void *module_name; /* Name of the module where the global variable is declared. */
154 unsigned long has_dynamic_init; /* This is needed for C++. */
155#if KASAN_ABI_VERSION >= 4
156 struct kasan_source_location *location;
157#endif
158#if KASAN_ABI_VERSION >= 5
159 char *odr_indicator;
160#endif
161};
162
163/* Structures for keeping alloc and free tracks. */
164
165#define KASAN_STACK_DEPTH 64
166
167struct kasan_track {
168 u32 pid;
169 depot_stack_handle_t stack;
170};
171
172#if defined(CONFIG_KASAN_TAGS_IDENTIFY) && defined(CONFIG_KASAN_SW_TAGS)
173#define KASAN_NR_FREE_STACKS 5
174#else
175#define KASAN_NR_FREE_STACKS 1
176#endif
177
178struct kasan_alloc_meta {
179 struct kasan_track alloc_track;
180 /* Generic mode stores free track in kasan_free_meta. */
181#ifdef CONFIG_KASAN_GENERIC
182 depot_stack_handle_t aux_stack[2];
183#else
184 struct kasan_track free_track[KASAN_NR_FREE_STACKS];
185#endif
186#ifdef CONFIG_KASAN_TAGS_IDENTIFY
187 u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
188 u8 free_track_idx;
189#endif
190};
191
192struct qlist_node {
193 struct qlist_node *next;
194};
195
196/*
197 * Free meta is stored either in the object itself or in the redzone after the
198 * object. In the former case, free meta offset is 0. In the latter case, the
199 * offset is between 0 and INT_MAX. INT_MAX marks that free meta is not present.
200 */
201#define KASAN_NO_FREE_META INT_MAX
202
203/*
204 * Free meta is only used by Generic mode while the object is in quarantine.
205 * After that, slab allocator stores the freelist pointer in the object.
206 */
207struct kasan_free_meta {
208#ifdef CONFIG_KASAN_GENERIC
209 struct qlist_node quarantine_link;
210 struct kasan_track free_track;
211#endif
212};
213
214#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
215/* Used in KUnit-compatible KASAN tests. */
216struct kunit_kasan_status {
217 bool report_found;
218 bool sync_fault;
219};
220#endif
221
222struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
223 const void *object);
224#ifdef CONFIG_KASAN_GENERIC
225struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
226 const void *object);
227#endif
228
229#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
230
231static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
232{
233 return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
234 << KASAN_SHADOW_SCALE_SHIFT);
235}
236
237static inline bool addr_has_metadata(const void *addr)
238{
239 return (kasan_reset_tag(addr) >=
240 kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
241}
242
243/**
244 * kasan_check_range - Check memory region, and report if invalid access.
245 * @addr: the accessed address
246 * @size: the accessed size
247 * @write: true if access is a write access
248 * @ret_ip: return address
249 * @return: true if access was valid, false if invalid
250 */
251bool kasan_check_range(unsigned long addr, size_t size, bool write,
252 unsigned long ret_ip);
253
254#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
255
256static inline bool addr_has_metadata(const void *addr)
257{
258 return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
259}
260
261#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
262
263#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
264void kasan_print_tags(u8 addr_tag, const void *addr);
265#else
266static inline void kasan_print_tags(u8 addr_tag, const void *addr) { }
267#endif
268
269void *kasan_find_first_bad_addr(void *addr, size_t size);
270const char *kasan_get_bug_type(struct kasan_report_info *info);
271void kasan_metadata_fetch_row(char *buffer, void *row);
272
273#if defined(CONFIG_KASAN_STACK)
274void kasan_print_address_stack_frame(const void *addr);
275#else
276static inline void kasan_print_address_stack_frame(const void *addr) { }
277#endif
278
279bool kasan_report(unsigned long addr, size_t size,
280 bool is_write, unsigned long ip);
281void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report_type type);
282
283struct page *kasan_addr_to_page(const void *addr);
284struct slab *kasan_addr_to_slab(const void *addr);
285
286depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
287void kasan_set_track(struct kasan_track *track, gfp_t flags);
288void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
289struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
290 void *object, u8 tag);
291
292#if defined(CONFIG_KASAN_GENERIC) && \
293 (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
294bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
295void kasan_quarantine_reduce(void);
296void kasan_quarantine_remove_cache(struct kmem_cache *cache);
297#else
298static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; }
299static inline void kasan_quarantine_reduce(void) { }
300static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { }
301#endif
302
303#ifndef arch_kasan_set_tag
304static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
305{
306 return addr;
307}
308#endif
309#ifndef arch_kasan_get_tag
310#define arch_kasan_get_tag(addr) 0
311#endif
312
313#define set_tag(addr, tag) ((void *)arch_kasan_set_tag((addr), (tag)))
314#define get_tag(addr) arch_kasan_get_tag(addr)
315
316#ifdef CONFIG_KASAN_HW_TAGS
317
318#ifndef arch_enable_tagging_sync
319#define arch_enable_tagging_sync()
320#endif
321#ifndef arch_enable_tagging_async
322#define arch_enable_tagging_async()
323#endif
324#ifndef arch_enable_tagging_asymm
325#define arch_enable_tagging_asymm()
326#endif
327#ifndef arch_force_async_tag_fault
328#define arch_force_async_tag_fault()
329#endif
330#ifndef arch_get_random_tag
331#define arch_get_random_tag() (0xFF)
332#endif
333#ifndef arch_get_mem_tag
334#define arch_get_mem_tag(addr) (0xFF)
335#endif
336#ifndef arch_set_mem_tag_range
337#define arch_set_mem_tag_range(addr, size, tag, init) ((void *)(addr))
338#endif
339
340#define hw_enable_tagging_sync() arch_enable_tagging_sync()
341#define hw_enable_tagging_async() arch_enable_tagging_async()
342#define hw_enable_tagging_asymm() arch_enable_tagging_asymm()
343#define hw_force_async_tag_fault() arch_force_async_tag_fault()
344#define hw_get_random_tag() arch_get_random_tag()
345#define hw_get_mem_tag(addr) arch_get_mem_tag(addr)
346#define hw_set_mem_tag_range(addr, size, tag, init) \
347 arch_set_mem_tag_range((addr), (size), (tag), (init))
348
349void kasan_enable_tagging(void);
350
351#else /* CONFIG_KASAN_HW_TAGS */
352
353#define hw_enable_tagging_sync()
354#define hw_enable_tagging_async()
355#define hw_enable_tagging_asymm()
356
357static inline void kasan_enable_tagging(void) { }
358
359#endif /* CONFIG_KASAN_HW_TAGS */
360
361#if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
362
363void kasan_force_async_fault(void);
364
365#else /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
366
367static inline void kasan_force_async_fault(void) { }
368
369#endif /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
370
371#ifdef CONFIG_KASAN_SW_TAGS
372u8 kasan_random_tag(void);
373#elif defined(CONFIG_KASAN_HW_TAGS)
374static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); }
375#else
376static inline u8 kasan_random_tag(void) { return 0; }
377#endif
378
379#ifdef CONFIG_KASAN_HW_TAGS
380
381static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
382{
383 addr = kasan_reset_tag(addr);
384
385 /* Skip KFENCE memory if called explicitly outside of sl*b. */
386 if (is_kfence_address(addr))
387 return;
388
389 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
390 return;
391 if (WARN_ON(size & KASAN_GRANULE_MASK))
392 return;
393
394 hw_set_mem_tag_range((void *)addr, size, value, init);
395}
396
397static inline void kasan_unpoison(const void *addr, size_t size, bool init)
398{
399 u8 tag = get_tag(addr);
400
401 addr = kasan_reset_tag(addr);
402
403 /* Skip KFENCE memory if called explicitly outside of sl*b. */
404 if (is_kfence_address(addr))
405 return;
406
407 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
408 return;
409 /*
410 * Explicitly initialize the memory with the precise object size to
411 * avoid overwriting the slab redzone. This disables initialization in
412 * the arch code and may thus lead to performance penalty. This penalty
413 * does not affect production builds, as slab redzones are not enabled
414 * there.
415 */
416 if (__slub_debug_enabled() &&
417 init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
418 init = false;
419 memzero_explicit((void *)addr, size);
420 }
421 size = round_up(size, KASAN_GRANULE_SIZE);
422
423 hw_set_mem_tag_range((void *)addr, size, tag, init);
424}
425
426static inline bool kasan_byte_accessible(const void *addr)
427{
428 u8 ptr_tag = get_tag(addr);
429 u8 mem_tag = hw_get_mem_tag((void *)addr);
430
431 return ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag;
432}
433
434#else /* CONFIG_KASAN_HW_TAGS */
435
436/**
437 * kasan_poison - mark the memory range as inaccessible
438 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
439 * @size - range size, must be aligned to KASAN_GRANULE_SIZE
440 * @value - value that's written to metadata for the range
441 * @init - whether to initialize the memory range (only for hardware tag-based)
442 *
443 * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
444 */
445void kasan_poison(const void *addr, size_t size, u8 value, bool init);
446
447/**
448 * kasan_unpoison - mark the memory range as accessible
449 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
450 * @size - range size, can be unaligned
451 * @init - whether to initialize the memory range (only for hardware tag-based)
452 *
453 * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before
454 * marking the range.
455 * For the generic mode, the last granule of the memory range gets partially
456 * unpoisoned based on the @size.
457 */
458void kasan_unpoison(const void *addr, size_t size, bool init);
459
460bool kasan_byte_accessible(const void *addr);
461
462#endif /* CONFIG_KASAN_HW_TAGS */
463
464#ifdef CONFIG_KASAN_GENERIC
465
466/**
467 * kasan_poison_last_granule - mark the last granule of the memory range as
468 * inaccessible
469 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
470 * @size - range size
471 *
472 * This function is only available for the generic mode, as it's the only mode
473 * that has partially poisoned memory granules.
474 */
475void kasan_poison_last_granule(const void *address, size_t size);
476
477#else /* CONFIG_KASAN_GENERIC */
478
479static inline void kasan_poison_last_granule(const void *address, size_t size) { }
480
481#endif /* CONFIG_KASAN_GENERIC */
482
483#ifndef kasan_arch_is_ready
484static inline bool kasan_arch_is_ready(void) { return true; }
485#elif !defined(CONFIG_KASAN_GENERIC) || !defined(CONFIG_KASAN_OUTLINE)
486#error kasan_arch_is_ready only works in KASAN generic outline mode!
487#endif
488
489#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST)
490
491bool kasan_save_enable_multi_shot(void);
492void kasan_restore_multi_shot(bool enabled);
493
494#endif
495
496/*
497 * Exported functions for interfaces called from assembly or from generated
498 * code. Declared here to avoid warnings about missing declarations.
499 */
500
501asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
502void __asan_register_globals(struct kasan_global *globals, size_t size);
503void __asan_unregister_globals(struct kasan_global *globals, size_t size);
504void __asan_handle_no_return(void);
505void __asan_alloca_poison(unsigned long addr, size_t size);
506void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
507
508void __asan_load1(unsigned long addr);
509void __asan_store1(unsigned long addr);
510void __asan_load2(unsigned long addr);
511void __asan_store2(unsigned long addr);
512void __asan_load4(unsigned long addr);
513void __asan_store4(unsigned long addr);
514void __asan_load8(unsigned long addr);
515void __asan_store8(unsigned long addr);
516void __asan_load16(unsigned long addr);
517void __asan_store16(unsigned long addr);
518void __asan_loadN(unsigned long addr, size_t size);
519void __asan_storeN(unsigned long addr, size_t size);
520
521void __asan_load1_noabort(unsigned long addr);
522void __asan_store1_noabort(unsigned long addr);
523void __asan_load2_noabort(unsigned long addr);
524void __asan_store2_noabort(unsigned long addr);
525void __asan_load4_noabort(unsigned long addr);
526void __asan_store4_noabort(unsigned long addr);
527void __asan_load8_noabort(unsigned long addr);
528void __asan_store8_noabort(unsigned long addr);
529void __asan_load16_noabort(unsigned long addr);
530void __asan_store16_noabort(unsigned long addr);
531void __asan_loadN_noabort(unsigned long addr, size_t size);
532void __asan_storeN_noabort(unsigned long addr, size_t size);
533
534void __asan_report_load1_noabort(unsigned long addr);
535void __asan_report_store1_noabort(unsigned long addr);
536void __asan_report_load2_noabort(unsigned long addr);
537void __asan_report_store2_noabort(unsigned long addr);
538void __asan_report_load4_noabort(unsigned long addr);
539void __asan_report_store4_noabort(unsigned long addr);
540void __asan_report_load8_noabort(unsigned long addr);
541void __asan_report_store8_noabort(unsigned long addr);
542void __asan_report_load16_noabort(unsigned long addr);
543void __asan_report_store16_noabort(unsigned long addr);
544void __asan_report_load_n_noabort(unsigned long addr, size_t size);
545void __asan_report_store_n_noabort(unsigned long addr, size_t size);
546
547void __asan_set_shadow_00(const void *addr, size_t size);
548void __asan_set_shadow_f1(const void *addr, size_t size);
549void __asan_set_shadow_f2(const void *addr, size_t size);
550void __asan_set_shadow_f3(const void *addr, size_t size);
551void __asan_set_shadow_f5(const void *addr, size_t size);
552void __asan_set_shadow_f8(const void *addr, size_t size);
553
554void __hwasan_load1_noabort(unsigned long addr);
555void __hwasan_store1_noabort(unsigned long addr);
556void __hwasan_load2_noabort(unsigned long addr);
557void __hwasan_store2_noabort(unsigned long addr);
558void __hwasan_load4_noabort(unsigned long addr);
559void __hwasan_store4_noabort(unsigned long addr);
560void __hwasan_load8_noabort(unsigned long addr);
561void __hwasan_store8_noabort(unsigned long addr);
562void __hwasan_load16_noabort(unsigned long addr);
563void __hwasan_store16_noabort(unsigned long addr);
564void __hwasan_loadN_noabort(unsigned long addr, size_t size);
565void __hwasan_storeN_noabort(unsigned long addr, size_t size);
566
567void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
568
569#endif /* __MM_KASAN_KASAN_H */
570

source code of linux/mm/kasan/kasan.h