xref: /linux/mm/kasan/kasan.h (revision 24ce659dcc02c21f8d6c0a7589c3320a4dfa8152)
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/stackdepot.h>
7 
8 #define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
9 #define KASAN_SHADOW_MASK       (KASAN_SHADOW_SCALE_SIZE - 1)
10 
11 #define KASAN_TAG_KERNEL	0xFF /* native kernel pointers tag */
12 #define KASAN_TAG_INVALID	0xFE /* inaccessible memory tag */
13 #define KASAN_TAG_MAX		0xFD /* maximum value for random tags */
14 
15 #ifdef CONFIG_KASAN_GENERIC
16 #define KASAN_FREE_PAGE         0xFF  /* page was freed */
17 #define KASAN_PAGE_REDZONE      0xFE  /* redzone for kmalloc_large allocations */
18 #define KASAN_KMALLOC_REDZONE   0xFC  /* redzone inside slub object */
19 #define KASAN_KMALLOC_FREE      0xFB  /* object was freed (kmem_cache_free/kfree) */
20 #else
21 #define KASAN_FREE_PAGE         KASAN_TAG_INVALID
22 #define KASAN_PAGE_REDZONE      KASAN_TAG_INVALID
23 #define KASAN_KMALLOC_REDZONE   KASAN_TAG_INVALID
24 #define KASAN_KMALLOC_FREE      KASAN_TAG_INVALID
25 #endif
26 
27 #define KASAN_GLOBAL_REDZONE    0xFA  /* redzone for global variable */
28 #define KASAN_VMALLOC_INVALID   0xF9  /* unallocated space in vmapped page */
29 
30 /*
31  * Stack redzone shadow values
32  * (Those are compiler's ABI, don't change them)
33  */
34 #define KASAN_STACK_LEFT        0xF1
35 #define KASAN_STACK_MID         0xF2
36 #define KASAN_STACK_RIGHT       0xF3
37 #define KASAN_STACK_PARTIAL     0xF4
38 
39 /*
40  * alloca redzone shadow values
41  */
42 #define KASAN_ALLOCA_LEFT	0xCA
43 #define KASAN_ALLOCA_RIGHT	0xCB
44 
45 #define KASAN_ALLOCA_REDZONE_SIZE	32
46 
47 /*
48  * Stack frame marker (compiler ABI).
49  */
50 #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3
51 
52 /* Don't break randconfig/all*config builds */
53 #ifndef KASAN_ABI_VERSION
54 #define KASAN_ABI_VERSION 1
55 #endif
56 
57 struct kasan_access_info {
58 	const void *access_addr;
59 	const void *first_bad_addr;
60 	size_t access_size;
61 	bool is_write;
62 	unsigned long ip;
63 };
64 
65 /* The layout of struct dictated by compiler */
66 struct kasan_source_location {
67 	const char *filename;
68 	int line_no;
69 	int column_no;
70 };
71 
72 /* The layout of struct dictated by compiler */
73 struct kasan_global {
74 	const void *beg;		/* Address of the beginning of the global variable. */
75 	size_t size;			/* Size of the global variable. */
76 	size_t size_with_redzone;	/* Size of the variable + size of the red zone. 32 bytes aligned */
77 	const void *name;
78 	const void *module_name;	/* Name of the module where the global variable is declared. */
79 	unsigned long has_dynamic_init;	/* This needed for C++ */
80 #if KASAN_ABI_VERSION >= 4
81 	struct kasan_source_location *location;
82 #endif
83 #if KASAN_ABI_VERSION >= 5
84 	char *odr_indicator;
85 #endif
86 };
87 
88 /**
89  * Structures to keep alloc and free tracks *
90  */
91 
92 #define KASAN_STACK_DEPTH 64
93 
94 struct kasan_track {
95 	u32 pid;
96 	depot_stack_handle_t stack;
97 };
98 
99 #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
100 #define KASAN_NR_FREE_STACKS 5
101 #else
102 #define KASAN_NR_FREE_STACKS 1
103 #endif
104 
105 struct kasan_alloc_meta {
106 	struct kasan_track alloc_track;
107 	struct kasan_track free_track[KASAN_NR_FREE_STACKS];
108 #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
109 	u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
110 	u8 free_track_idx;
111 #endif
112 };
113 
114 struct qlist_node {
115 	struct qlist_node *next;
116 };
117 struct kasan_free_meta {
118 	/* This field is used while the object is in the quarantine.
119 	 * Otherwise it might be used for the allocator freelist.
120 	 */
121 	struct qlist_node quarantine_link;
122 };
123 
124 struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
125 					const void *object);
126 struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
127 					const void *object);
128 
129 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
130 {
131 	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
132 		<< KASAN_SHADOW_SCALE_SHIFT);
133 }
134 
135 static inline bool addr_has_shadow(const void *addr)
136 {
137 	return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
138 }
139 
140 void kasan_poison_shadow(const void *address, size_t size, u8 value);
141 
142 /**
143  * check_memory_region - Check memory region, and report if invalid access.
144  * @addr: the accessed address
145  * @size: the accessed size
146  * @write: true if access is a write access
147  * @ret_ip: return address
148  * @return: true if access was valid, false if invalid
149  */
150 bool check_memory_region(unsigned long addr, size_t size, bool write,
151 				unsigned long ret_ip);
152 
153 void *find_first_bad_addr(void *addr, size_t size);
154 const char *get_bug_type(struct kasan_access_info *info);
155 
156 bool kasan_report(unsigned long addr, size_t size,
157 		bool is_write, unsigned long ip);
158 void kasan_report_invalid_free(void *object, unsigned long ip);
159 
160 struct page *kasan_addr_to_page(const void *addr);
161 
162 #if defined(CONFIG_KASAN_GENERIC) && \
163 	(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
164 void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
165 void quarantine_reduce(void);
166 void quarantine_remove_cache(struct kmem_cache *cache);
167 #else
168 static inline void quarantine_put(struct kasan_free_meta *info,
169 				struct kmem_cache *cache) { }
170 static inline void quarantine_reduce(void) { }
171 static inline void quarantine_remove_cache(struct kmem_cache *cache) { }
172 #endif
173 
174 #ifdef CONFIG_KASAN_SW_TAGS
175 
176 void print_tags(u8 addr_tag, const void *addr);
177 
178 u8 random_tag(void);
179 
180 #else
181 
182 static inline void print_tags(u8 addr_tag, const void *addr) { }
183 
184 static inline u8 random_tag(void)
185 {
186 	return 0;
187 }
188 
189 #endif
190 
191 #ifndef arch_kasan_set_tag
192 static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
193 {
194 	return addr;
195 }
196 #endif
197 #ifndef arch_kasan_reset_tag
198 #define arch_kasan_reset_tag(addr)	((void *)(addr))
199 #endif
200 #ifndef arch_kasan_get_tag
201 #define arch_kasan_get_tag(addr)	0
202 #endif
203 
204 #define set_tag(addr, tag)	((void *)arch_kasan_set_tag((addr), (tag)))
205 #define reset_tag(addr)		((void *)arch_kasan_reset_tag(addr))
206 #define get_tag(addr)		arch_kasan_get_tag(addr)
207 
208 /*
209  * Exported functions for interfaces called from assembly or from generated
210  * code. Declarations here to avoid warning about missing declarations.
211  */
212 asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
213 void __asan_register_globals(struct kasan_global *globals, size_t size);
214 void __asan_unregister_globals(struct kasan_global *globals, size_t size);
215 void __asan_loadN(unsigned long addr, size_t size);
216 void __asan_storeN(unsigned long addr, size_t size);
217 void __asan_handle_no_return(void);
218 void __asan_alloca_poison(unsigned long addr, size_t size);
219 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
220 
221 void __asan_load1(unsigned long addr);
222 void __asan_store1(unsigned long addr);
223 void __asan_load2(unsigned long addr);
224 void __asan_store2(unsigned long addr);
225 void __asan_load4(unsigned long addr);
226 void __asan_store4(unsigned long addr);
227 void __asan_load8(unsigned long addr);
228 void __asan_store8(unsigned long addr);
229 void __asan_load16(unsigned long addr);
230 void __asan_store16(unsigned long addr);
231 
232 void __asan_load1_noabort(unsigned long addr);
233 void __asan_store1_noabort(unsigned long addr);
234 void __asan_load2_noabort(unsigned long addr);
235 void __asan_store2_noabort(unsigned long addr);
236 void __asan_load4_noabort(unsigned long addr);
237 void __asan_store4_noabort(unsigned long addr);
238 void __asan_load8_noabort(unsigned long addr);
239 void __asan_store8_noabort(unsigned long addr);
240 void __asan_load16_noabort(unsigned long addr);
241 void __asan_store16_noabort(unsigned long addr);
242 
243 void __asan_set_shadow_00(const void *addr, size_t size);
244 void __asan_set_shadow_f1(const void *addr, size_t size);
245 void __asan_set_shadow_f2(const void *addr, size_t size);
246 void __asan_set_shadow_f3(const void *addr, size_t size);
247 void __asan_set_shadow_f5(const void *addr, size_t size);
248 void __asan_set_shadow_f8(const void *addr, size_t size);
249 
250 #endif
251