xref: /openbmc/linux/mm/kasan/kasan.h (revision 7587eb18)
1 #ifndef __MM_KASAN_KASAN_H
2 #define __MM_KASAN_KASAN_H
3 
4 #include <linux/kasan.h>
5 #include <linux/stackdepot.h>
6 
7 #define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
8 #define KASAN_SHADOW_MASK       (KASAN_SHADOW_SCALE_SIZE - 1)
9 
10 #define KASAN_FREE_PAGE         0xFF  /* page was freed */
11 #define KASAN_PAGE_REDZONE      0xFE  /* redzone for kmalloc_large allocations */
12 #define KASAN_KMALLOC_REDZONE   0xFC  /* redzone inside slub object */
13 #define KASAN_KMALLOC_FREE      0xFB  /* object was freed (kmem_cache_free/kfree) */
14 #define KASAN_GLOBAL_REDZONE    0xFA  /* redzone for global variable */
15 
16 /*
17  * Stack redzone shadow values
18  * (Those are compiler's ABI, don't change them)
19  */
20 #define KASAN_STACK_LEFT        0xF1
21 #define KASAN_STACK_MID         0xF2
22 #define KASAN_STACK_RIGHT       0xF3
23 #define KASAN_STACK_PARTIAL     0xF4
24 
25 /* Don't break randconfig/all*config builds */
26 #ifndef KASAN_ABI_VERSION
27 #define KASAN_ABI_VERSION 1
28 #endif
29 
30 struct kasan_access_info {
31 	const void *access_addr;
32 	const void *first_bad_addr;
33 	size_t access_size;
34 	bool is_write;
35 	unsigned long ip;
36 };
37 
38 /* The layout of struct dictated by compiler */
39 struct kasan_source_location {
40 	const char *filename;
41 	int line_no;
42 	int column_no;
43 };
44 
45 /* The layout of struct dictated by compiler */
46 struct kasan_global {
47 	const void *beg;		/* Address of the beginning of the global variable. */
48 	size_t size;			/* Size of the global variable. */
49 	size_t size_with_redzone;	/* Size of the variable + size of the red zone. 32 bytes aligned */
50 	const void *name;
51 	const void *module_name;	/* Name of the module where the global variable is declared. */
52 	unsigned long has_dynamic_init;	/* This needed for C++ */
53 #if KASAN_ABI_VERSION >= 4
54 	struct kasan_source_location *location;
55 #endif
56 };
57 
58 /**
59  * Structures to keep alloc and free tracks *
60  */
61 
62 enum kasan_state {
63 	KASAN_STATE_INIT,
64 	KASAN_STATE_ALLOC,
65 	KASAN_STATE_QUARANTINE,
66 	KASAN_STATE_FREE
67 };
68 
69 #define KASAN_STACK_DEPTH 64
70 
71 struct kasan_track {
72 	u32 pid;
73 	depot_stack_handle_t stack;
74 };
75 
76 struct kasan_alloc_meta {
77 	struct kasan_track track;
78 	u32 state : 2;	/* enum kasan_state */
79 	u32 alloc_size : 30;
80 };
81 
82 struct qlist_node {
83 	struct qlist_node *next;
84 };
85 struct kasan_free_meta {
86 	/* This field is used while the object is in the quarantine.
87 	 * Otherwise it might be used for the allocator freelist.
88 	 */
89 	struct qlist_node quarantine_link;
90 	struct kasan_track track;
91 };
92 
93 struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,
94 					const void *object);
95 struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
96 					const void *object);
97 
98 
99 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
100 {
101 	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
102 		<< KASAN_SHADOW_SCALE_SHIFT);
103 }
104 
105 static inline bool kasan_report_enabled(void)
106 {
107 	return !current->kasan_depth;
108 }
109 
110 void kasan_report(unsigned long addr, size_t size,
111 		bool is_write, unsigned long ip);
112 
113 #ifdef CONFIG_SLAB
114 void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache);
115 void quarantine_reduce(void);
116 void quarantine_remove_cache(struct kmem_cache *cache);
117 #else
118 static inline void quarantine_put(struct kasan_free_meta *info,
119 				struct kmem_cache *cache) { }
120 static inline void quarantine_reduce(void) { }
121 static inline void quarantine_remove_cache(struct kmem_cache *cache) { }
122 #endif
123 
124 #endif
125