summaryrefslogtreecommitdiff
path: root/mm/kasan/kasan.h
blob: e8f37199d885172cfb2ae948e7134520e07718ad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __MM_KASAN_KASAN_H
#define __MM_KASAN_KASAN_H

#include <linux/kasan.h>
#include <linux/stackdepot.h>

#define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
#define KASAN_SHADOW_MASK       (KASAN_SHADOW_SCALE_SIZE - 1)

#define KASAN_TAG_KERNEL	0xFF /* native kernel pointers tag */
#define KASAN_TAG_INVALID	0xFE /* inaccessible memory tag */
#define KASAN_TAG_MAX		0xFD /* maximum value for random tags */

#ifdef CONFIG_KASAN_GENERIC
#define KASAN_FREE_PAGE         0xFF  /* page was freed */
#define KASAN_PAGE_REDZONE      0xFE  /* redzone for kmalloc_large allocations */
#define KASAN_KMALLOC_REDZONE   0xFC  /* redzone inside slub object */
#define KASAN_KMALLOC_FREE      0xFB  /* object was freed (kmem_cache_free/kfree) */
#else
#define KASAN_FREE_PAGE         KASAN_TAG_INVALID
#define KASAN_PAGE_REDZONE      KASAN_TAG_INVALID
#define KASAN_KMALLOC_REDZONE   KASAN_TAG_INVALID
#define KASAN_KMALLOC_FREE      KASAN_TAG_INVALID
#endif

#define KASAN_GLOBAL_REDZONE    0xFA  /* redzone for global variable */
#define KASAN_VMALLOC_INVALID   0xF9  /* unallocated space in vmapped page */

/*
 * Stack redzone shadow values
 * (Those are compiler's ABI, don't change them)
 */
#define KASAN_STACK_LEFT        0xF1
#define KASAN_STACK_MID         0xF2
#define KASAN_STACK_RIGHT       0xF3
#define KASAN_STACK_PARTIAL     0xF4

/*
 * alloca redzone shadow values
 */
#define KASAN_ALLOCA_LEFT	0xCA
#define KASAN_ALLOCA_RIGHT	0xCB

#define KASAN_ALLOCA_REDZONE_SIZE	32

/*
 * Stack frame marker (compiler ABI).
 */
#define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3

/* Don't break randconfig/all*config builds */
#ifndef KASAN_ABI_VERSION
#define KASAN_ABI_VERSION 1
#endif

struct kasan_access_info {
	const void *access_addr;
	const void *first_bad_addr;
	size_t access_size;
	bool is_write;
	unsigned long ip;
};

/* The layout of struct dictated by compiler */
struct kasan_source_location {
	const char *filename;
	int line_no;
	int column_no;
};

/* The layout of struct dictated by compiler */
struct kasan_global {
	const void *beg;		/* Address of the beginning of the global variable. */
	size_t size;			/* Size of the global variable. */
	size_t size_with_redzone;	/* Size of the variable + size of the red zone. 32 bytes aligned */
	const void *name;
	const void *module_name;	/* Name of the module where the global variable is declared. */
	unsigned long has_dynamic_init;	/* This needed for C++ */
#if KASAN_ABI_VERSION >= 4
	struct kasan_source_location *location;
#endif
#if KASAN_ABI_VERSION >= 5
	char *odr_indicator;
#endif
};

/**
 * Structures to keep alloc and free tracks *
 */

#define KASAN_STACK_DEPTH 64

struct kasan_track {
	u32 pid;
	depot_stack_handle_t stack;
};

#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
#define KASAN_NR_FREE_STACKS 5
#else
#define KASAN_NR_FREE_STACKS 1
#endif

struct kasan_alloc_meta {
	struct kasan_track alloc_track;
	struct kasan_track free_track[KASAN_NR_FREE_STACKS];
#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
	u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
	u8 free_track_idx;
#endif
};

struct qlist_node {
	struct qlist_node *next;
};
struct kasan_free_meta {
	/* This field is used while the object is in the quarantine.
	 * Otherwise it might be used for the allocator freelist.
	 */
	struct qlist_node quarantine_link;
};

struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
					const void *object);
struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
					const void *object);

static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
{
	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
		<< KASAN_SHADOW_SCALE_SHIFT);
}

static inline bool addr_has_shadow(const void *addr)
{
	return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
}

void kasan_poison_shadow(const void *address, size_t size, u8 value);

/**
 * check_memory_region - Check memory region, and report if invalid access.
 * @addr: the accessed address
 * @size: the accessed size
 * @write: true if access is a write access
 * @ret_ip: return address
 * @return: true if access was valid, false if invalid
 */
bool check_memory_region(unsigned long addr, size_t size, bool write,
				unsigned long ret_ip);

void *find_first_bad_addr(void *addr, size_t size);
const char *get_bug_type(struct kasan_access_info *info);

bool kasan_report(unsigned long addr, size_t size,
		bool is_write, unsigned long ip);
void kasan_report_invalid_free(void *object, unsigned long ip);

struct page *kasan_addr_to_page(const void *addr);

#if defined(CONFIG_KASAN_GENERIC) && \
	(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
void quarantine_reduce(void);
void quarantine_remove_cache(struct kmem_cache *cache);
#else
static inline void quarantine_put(struct kasan_free_meta *info,
				struct kmem_cache *cache) { }
static inline void quarantine_reduce(void) { }
static inline void quarantine_remove_cache(struct kmem_cache *cache) { }
#endif

#ifdef CONFIG_KASAN_SW_TAGS

void print_tags(u8 addr_tag, const void *addr);

u8 random_tag(void);

#else

static inline void print_tags(u8 addr_tag, const void *addr) { }

static inline u8 random_tag(void)
{
	return 0;
}

#endif

#ifndef arch_kasan_set_tag
static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
{
	return addr;
}
#endif
#ifndef arch_kasan_reset_tag
#define arch_kasan_reset_tag(addr)	((void *)(addr))
#endif
#ifndef arch_kasan_get_tag
#define arch_kasan_get_tag(addr)	0
#endif

#define set_tag(addr, tag)	((void *)arch_kasan_set_tag((addr), (tag)))
#define reset_tag(addr)		((void *)arch_kasan_reset_tag(addr))
#define get_tag(addr)		arch_kasan_get_tag(addr)

/*
 * Exported functions for interfaces called from assembly or from generated
 * code. Declarations here to avoid warning about missing declarations.
 */
asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
void __asan_register_globals(struct kasan_global *globals, size_t size);
void __asan_unregister_globals(struct kasan_global *globals, size_t size);
void __asan_loadN(unsigned long addr, size_t size);
void __asan_storeN(unsigned long addr, size_t size);
void __asan_handle_no_return(void);
void __asan_alloca_poison(unsigned long addr, size_t size);
void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);

void __asan_load1(unsigned long addr);
void __asan_store1(unsigned long addr);
void __asan_load2(unsigned long addr);
void __asan_store2(unsigned long addr);
void __asan_load4(unsigned long addr);
void __asan_store4(unsigned long addr);
void __asan_load8(unsigned long addr);
void __asan_store8(unsigned long addr);
void __asan_load16(unsigned long addr);
void __asan_store16(unsigned long addr);

void __asan_load1_noabort(unsigned long addr);
void __asan_store1_noabort(unsigned long addr);
void __asan_load2_noabort(unsigned long addr);
void __asan_store2_noabort(unsigned long addr);
void __asan_load4_noabort(unsigned long addr);
void __asan_store4_noabort(unsigned long addr);
void __asan_load8_noabort(unsigned long addr);
void __asan_store8_noabort(unsigned long addr);
void __asan_load16_noabort(unsigned long addr);
void __asan_store16_noabort(unsigned long addr);

void __asan_set_shadow_00(const void *addr, size_t size);
void __asan_set_shadow_f1(const void *addr, size_t size);
void __asan_set_shadow_f2(const void *addr, size_t size);
void __asan_set_shadow_f3(const void *addr, size_t size);
void __asan_set_shadow_f5(const void *addr, size_t size);
void __asan_set_shadow_f8(const void *addr, size_t size);

#endif