xref: /openbmc/linux/mm/kasan/kasan.h (revision 82b5d164)
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 
29 /*
30  * Stack redzone shadow values
31  * (Those are compiler's ABI, don't change them)
32  */
33 #define KASAN_STACK_LEFT        0xF1
34 #define KASAN_STACK_MID         0xF2
35 #define KASAN_STACK_RIGHT       0xF3
36 #define KASAN_STACK_PARTIAL     0xF4
37 
38 /*
39  * alloca redzone shadow values
40  */
41 #define KASAN_ALLOCA_LEFT	0xCA
42 #define KASAN_ALLOCA_RIGHT	0xCB
43 
44 #define KASAN_ALLOCA_REDZONE_SIZE	32
45 
46 /*
47  * Stack frame marker (compiler ABI).
48  */
49 #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3
50 
51 /* Don't break randconfig/all*config builds */
52 #ifndef KASAN_ABI_VERSION
53 #define KASAN_ABI_VERSION 1
54 #endif
55 
56 struct kasan_access_info {
57 	const void *access_addr;
58 	const void *first_bad_addr;
59 	size_t access_size;
60 	bool is_write;
61 	unsigned long ip;
62 };
63 
64 /* The layout of struct dictated by compiler */
65 struct kasan_source_location {
66 	const char *filename;
67 	int line_no;
68 	int column_no;
69 };
70 
71 /* The layout of struct dictated by compiler */
72 struct kasan_global {
73 	const void *beg;		/* Address of the beginning of the global variable. */
74 	size_t size;			/* Size of the global variable. */
75 	size_t size_with_redzone;	/* Size of the variable + size of the red zone. 32 bytes aligned */
76 	const void *name;
77 	const void *module_name;	/* Name of the module where the global variable is declared. */
78 	unsigned long has_dynamic_init;	/* This needed for C++ */
79 #if KASAN_ABI_VERSION >= 4
80 	struct kasan_source_location *location;
81 #endif
82 #if KASAN_ABI_VERSION >= 5
83 	char *odr_indicator;
84 #endif
85 };
86 
87 /**
88  * Structures to keep alloc and free tracks *
89  */
90 
91 #define KASAN_STACK_DEPTH 64
92 
93 struct kasan_track {
94 	u32 pid;
95 	depot_stack_handle_t stack;
96 };
97 
98 #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
99 #define KASAN_NR_FREE_STACKS 5
100 #else
101 #define KASAN_NR_FREE_STACKS 1
102 #endif
103 
104 struct kasan_alloc_meta {
105 	struct kasan_track alloc_track;
106 	struct kasan_track free_track[KASAN_NR_FREE_STACKS];
107 #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
108 	u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
109 	u8 free_track_idx;
110 #endif
111 };
112 
113 struct qlist_node {
114 	struct qlist_node *next;
115 };
116 struct kasan_free_meta {
117 	/* This field is used while the object is in the quarantine.
118 	 * Otherwise it might be used for the allocator freelist.
119 	 */
120 	struct qlist_node quarantine_link;
121 };
122 
123 struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
124 					const void *object);
125 struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
126 					const void *object);
127 
128 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
129 {
130 	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
131 		<< KASAN_SHADOW_SCALE_SHIFT);
132 }
133 
134 static inline bool addr_has_shadow(const void *addr)
135 {
136 	return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
137 }
138 
139 void kasan_poison_shadow(const void *address, size_t size, u8 value);
140 
141 /**
142  * check_memory_region - Check memory region, and report if invalid access.
143  * @addr: the accessed address
144  * @size: the accessed size
145  * @write: true if access is a write access
146  * @ret_ip: return address
147  * @return: true if access was valid, false if invalid
148  */
149 bool check_memory_region(unsigned long addr, size_t size, bool write,
150 				unsigned long ret_ip);
151 
152 void *find_first_bad_addr(void *addr, size_t size);
153 const char *get_bug_type(struct kasan_access_info *info);
154 
155 void kasan_report(unsigned long addr, size_t size,
156 		bool is_write, unsigned long ip);
157 void kasan_report_invalid_free(void *object, unsigned long ip);
158 
159 struct page *kasan_addr_to_page(const void *addr);
160 
161 #if defined(CONFIG_KASAN_GENERIC) && \
162 	(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
163 void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
164 void quarantine_reduce(void);
165 void quarantine_remove_cache(struct kmem_cache *cache);
166 #else
167 static inline void quarantine_put(struct kasan_free_meta *info,
168 				struct kmem_cache *cache) { }
169 static inline void quarantine_reduce(void) { }
170 static inline void quarantine_remove_cache(struct kmem_cache *cache) { }
171 #endif
172 
173 #ifdef CONFIG_KASAN_SW_TAGS
174 
175 void print_tags(u8 addr_tag, const void *addr);
176 
177 u8 random_tag(void);
178 
179 #else
180 
181 static inline void print_tags(u8 addr_tag, const void *addr) { }
182 
183 static inline u8 random_tag(void)
184 {
185 	return 0;
186 }
187 
188 #endif
189 
190 #ifndef arch_kasan_set_tag
191 static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
192 {
193 	return addr;
194 }
195 #endif
196 #ifndef arch_kasan_reset_tag
197 #define arch_kasan_reset_tag(addr)	((void *)(addr))
198 #endif
199 #ifndef arch_kasan_get_tag
200 #define arch_kasan_get_tag(addr)	0
201 #endif
202 
203 #define set_tag(addr, tag)	((void *)arch_kasan_set_tag((addr), (tag)))
204 #define reset_tag(addr)		((void *)arch_kasan_reset_tag(addr))
205 #define get_tag(addr)		arch_kasan_get_tag(addr)
206 
207 /*
208  * Exported functions for interfaces called from assembly or from generated
209  * code. Declarations here to avoid warning about missing declarations.
210  */
211 asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
212 void __asan_register_globals(struct kasan_global *globals, size_t size);
213 void __asan_unregister_globals(struct kasan_global *globals, size_t size);
214 void __asan_loadN(unsigned long addr, size_t size);
215 void __asan_storeN(unsigned long addr, size_t size);
216 void __asan_handle_no_return(void);
217 void __asan_alloca_poison(unsigned long addr, size_t size);
218 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
219 
220 void __asan_load1(unsigned long addr);
221 void __asan_store1(unsigned long addr);
222 void __asan_load2(unsigned long addr);
223 void __asan_store2(unsigned long addr);
224 void __asan_load4(unsigned long addr);
225 void __asan_store4(unsigned long addr);
226 void __asan_load8(unsigned long addr);
227 void __asan_store8(unsigned long addr);
228 void __asan_load16(unsigned long addr);
229 void __asan_store16(unsigned long addr);
230 
231 void __asan_load1_noabort(unsigned long addr);
232 void __asan_store1_noabort(unsigned long addr);
233 void __asan_load2_noabort(unsigned long addr);
234 void __asan_store2_noabort(unsigned long addr);
235 void __asan_load4_noabort(unsigned long addr);
236 void __asan_store4_noabort(unsigned long addr);
237 void __asan_load8_noabort(unsigned long addr);
238 void __asan_store8_noabort(unsigned long addr);
239 void __asan_load16_noabort(unsigned long addr);
240 void __asan_store16_noabort(unsigned long addr);
241 
242 void __asan_set_shadow_00(const void *addr, size_t size);
243 void __asan_set_shadow_f1(const void *addr, size_t size);
244 void __asan_set_shadow_f2(const void *addr, size_t size);
245 void __asan_set_shadow_f3(const void *addr, size_t size);
246 void __asan_set_shadow_f5(const void *addr, size_t size);
247 void __asan_set_shadow_f8(const void *addr, size_t size);
248 
249 #endif
250