include/linux/kasan.h

   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 <asm/kasan.h>
  15 #include <asm/pgtable.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 void 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 requested_size,
 209                            struct vm_struct *area);
 210 void kasan_poison_vmalloc(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 requested_size,
 216                                          struct vm_struct *area)
 217 {
 218         return 0;
 219 }
 220
 221 static inline void kasan_poison_vmalloc(void *start, unsigned long size) {}
 222 static inline void kasan_release_vmalloc(unsigned long start,
 223                                          unsigned long end,
 224                                          unsigned long free_region_start,
 225                                          unsigned long free_region_end) {}
 226 #endif
 227
 228 #endif /* LINUX_KASAN_H */