xref: /openbmc/linux/include/linux/kasan.h (revision 132db935)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_KASAN_H
3 #define _LINUX_KASAN_H
4 
5 #include <linux/types.h>
6 
7 struct kmem_cache;
8 struct page;
9 struct vm_struct;
10 struct task_struct;
11 
12 #ifdef CONFIG_KASAN
13 
14 #include <linux/pgtable.h>
15 #include <asm/kasan.h>
16 
17 extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
18 extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE];
19 extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD];
20 extern pud_t kasan_early_shadow_pud[PTRS_PER_PUD];
21 extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
22 
23 int kasan_populate_early_shadow(const void *shadow_start,
24 				const void *shadow_end);
25 
26 static inline void *kasan_mem_to_shadow(const void *addr)
27 {
28 	return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
29 		+ KASAN_SHADOW_OFFSET;
30 }
31 
32 /* Enable reporting bugs after kasan_disable_current() */
33 extern void kasan_enable_current(void);
34 
35 /* Disable reporting bugs for current task */
36 extern void kasan_disable_current(void);
37 
38 void kasan_unpoison_shadow(const void *address, size_t size);
39 
40 void kasan_unpoison_task_stack(struct task_struct *task);
41 void kasan_unpoison_stack_above_sp_to(const void *watermark);
42 
43 void kasan_alloc_pages(struct page *page, unsigned int order);
44 void kasan_free_pages(struct page *page, unsigned int order);
45 
46 void kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
47 			slab_flags_t *flags);
48 
49 void kasan_poison_slab(struct page *page);
50 void kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
51 void kasan_poison_object_data(struct kmem_cache *cache, void *object);
52 void * __must_check kasan_init_slab_obj(struct kmem_cache *cache,
53 					const void *object);
54 
55 void * __must_check kasan_kmalloc_large(const void *ptr, size_t size,
56 						gfp_t flags);
57 void kasan_kfree_large(void *ptr, unsigned long ip);
58 void kasan_poison_kfree(void *ptr, unsigned long ip);
59 void * __must_check kasan_kmalloc(struct kmem_cache *s, const void *object,
60 					size_t size, gfp_t flags);
61 void * __must_check kasan_krealloc(const void *object, size_t new_size,
62 					gfp_t flags);
63 
64 void * __must_check kasan_slab_alloc(struct kmem_cache *s, void *object,
65 					gfp_t flags);
66 bool kasan_slab_free(struct kmem_cache *s, void *object, unsigned long ip);
67 
68 struct kasan_cache {
69 	int alloc_meta_offset;
70 	int free_meta_offset;
71 };
72 
73 /*
74  * These functions provide a special case to support backing module
75  * allocations with real shadow memory. With KASAN vmalloc, the special
76  * case is unnecessary, as the work is handled in the generic case.
77  */
78 #ifndef CONFIG_KASAN_VMALLOC
79 int kasan_module_alloc(void *addr, size_t size);
80 void kasan_free_shadow(const struct vm_struct *vm);
81 #else
82 static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
83 static inline void kasan_free_shadow(const struct vm_struct *vm) {}
84 #endif
85 
86 int kasan_add_zero_shadow(void *start, unsigned long size);
87 void kasan_remove_zero_shadow(void *start, unsigned long size);
88 
89 size_t __ksize(const void *);
90 static inline void kasan_unpoison_slab(const void *ptr)
91 {
92 	kasan_unpoison_shadow(ptr, __ksize(ptr));
93 }
94 size_t kasan_metadata_size(struct kmem_cache *cache);
95 
96 bool kasan_save_enable_multi_shot(void);
97 void kasan_restore_multi_shot(bool enabled);
98 
99 #else /* CONFIG_KASAN */
100 
101 static inline void kasan_unpoison_shadow(const void *address, size_t size) {}
102 
103 static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
104 static inline void kasan_unpoison_stack_above_sp_to(const void *watermark) {}
105 
106 static inline void kasan_enable_current(void) {}
107 static inline void kasan_disable_current(void) {}
108 
109 static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
110 static inline void kasan_free_pages(struct page *page, unsigned int order) {}
111 
112 static inline void kasan_cache_create(struct kmem_cache *cache,
113 				      unsigned int *size,
114 				      slab_flags_t *flags) {}
115 
116 static inline void kasan_poison_slab(struct page *page) {}
117 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
118 					void *object) {}
119 static inline void kasan_poison_object_data(struct kmem_cache *cache,
120 					void *object) {}
121 static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
122 				const void *object)
123 {
124 	return (void *)object;
125 }
126 
127 static inline void *kasan_kmalloc_large(void *ptr, size_t size, gfp_t flags)
128 {
129 	return ptr;
130 }
131 static inline void kasan_kfree_large(void *ptr, unsigned long ip) {}
132 static inline void kasan_poison_kfree(void *ptr, unsigned long ip) {}
133 static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object,
134 				size_t size, gfp_t flags)
135 {
136 	return (void *)object;
137 }
138 static inline void *kasan_krealloc(const void *object, size_t new_size,
139 				 gfp_t flags)
140 {
141 	return (void *)object;
142 }
143 
144 static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
145 				   gfp_t flags)
146 {
147 	return object;
148 }
149 static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
150 				   unsigned long ip)
151 {
152 	return false;
153 }
154 
155 static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
156 static inline void kasan_free_shadow(const struct vm_struct *vm) {}
157 
158 static inline int kasan_add_zero_shadow(void *start, unsigned long size)
159 {
160 	return 0;
161 }
162 static inline void kasan_remove_zero_shadow(void *start,
163 					unsigned long size)
164 {}
165 
166 static inline void kasan_unpoison_slab(const void *ptr) { }
167 static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
168 
169 #endif /* CONFIG_KASAN */
170 
171 #ifdef CONFIG_KASAN_GENERIC
172 
173 #define KASAN_SHADOW_INIT 0
174 
175 void kasan_cache_shrink(struct kmem_cache *cache);
176 void kasan_cache_shutdown(struct kmem_cache *cache);
177 
178 #else /* CONFIG_KASAN_GENERIC */
179 
180 static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
181 static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
182 
183 #endif /* CONFIG_KASAN_GENERIC */
184 
185 #ifdef CONFIG_KASAN_SW_TAGS
186 
187 #define KASAN_SHADOW_INIT 0xFF
188 
189 void kasan_init_tags(void);
190 
191 void *kasan_reset_tag(const void *addr);
192 
193 bool kasan_report(unsigned long addr, size_t size,
194 		bool is_write, unsigned long ip);
195 
196 #else /* CONFIG_KASAN_SW_TAGS */
197 
198 static inline void kasan_init_tags(void) { }
199 
200 static inline void *kasan_reset_tag(const void *addr)
201 {
202 	return (void *)addr;
203 }
204 
205 #endif /* CONFIG_KASAN_SW_TAGS */
206 
207 #ifdef CONFIG_KASAN_VMALLOC
208 int kasan_populate_vmalloc(unsigned long addr, unsigned long size);
209 void kasan_poison_vmalloc(const void *start, unsigned long size);
210 void kasan_unpoison_vmalloc(const void *start, unsigned long size);
211 void kasan_release_vmalloc(unsigned long start, unsigned long end,
212 			   unsigned long free_region_start,
213 			   unsigned long free_region_end);
214 #else
215 static inline int kasan_populate_vmalloc(unsigned long start,
216 					unsigned long size)
217 {
218 	return 0;
219 }
220 
221 static inline void kasan_poison_vmalloc(const void *start, unsigned long size)
222 { }
223 static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size)
224 { }
225 static inline void kasan_release_vmalloc(unsigned long start,
226 					 unsigned long end,
227 					 unsigned long free_region_start,
228 					 unsigned long free_region_end) {}
229 #endif
230 
231 #ifdef CONFIG_KASAN_INLINE
232 void kasan_non_canonical_hook(unsigned long addr);
233 #else /* CONFIG_KASAN_INLINE */
234 static inline void kasan_non_canonical_hook(unsigned long addr) { }
235 #endif /* CONFIG_KASAN_INLINE */
236 
237 #endif /* LINUX_KASAN_H */
238