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/bug.h>
   6 #include <linux/kasan-enabled.h>
   7 #include <linux/kernel.h>
   8 #include <linux/static_key.h>
   9 #include <linux/types.h>
  10
  11 struct kmem_cache;
  12 struct page;
  13 struct slab;
  14 struct vm_struct;
  15 struct task_struct;
  16
  17 #ifdef CONFIG_KASAN
  18
  19 #include <linux/linkage.h>
  20 #include <asm/kasan.h>
  21
  22 #endif
  23
  24 typedef unsigned int __bitwise kasan_vmalloc_flags_t;
  25
  26 #define KASAN_VMALLOC_NONE              ((__force kasan_vmalloc_flags_t)0x00u)
  27 #define KASAN_VMALLOC_INIT              ((__force kasan_vmalloc_flags_t)0x01u)
  28 #define KASAN_VMALLOC_VM_ALLOC          ((__force kasan_vmalloc_flags_t)0x02u)
  29 #define KASAN_VMALLOC_PROT_NORMAL       ((__force kasan_vmalloc_flags_t)0x04u)
  30
  31 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
  32
  33 #include <linux/pgtable.h>
  34
  35 /* Software KASAN implementations use shadow memory. */
  36
  37 #ifdef CONFIG_KASAN_SW_TAGS
  38 /* This matches KASAN_TAG_INVALID. */
  39 #define KASAN_SHADOW_INIT 0xFE
  40 #else
  41 #define KASAN_SHADOW_INIT 0
  42 #endif
  43
  44 #ifndef PTE_HWTABLE_PTRS
  45 #define PTE_HWTABLE_PTRS 0
  46 #endif
  47
  48 extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
  49 extern pte_t kasan_early_shadow_pte[MAX_PTRS_PER_PTE + PTE_HWTABLE_PTRS];
  50 extern pmd_t kasan_early_shadow_pmd[MAX_PTRS_PER_PMD];
  51 extern pud_t kasan_early_shadow_pud[MAX_PTRS_PER_PUD];
  52 extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
  53
  54 int kasan_populate_early_shadow(const void *shadow_start,
  55                                 const void *shadow_end);
  56
  57 static inline void *kasan_mem_to_shadow(const void *addr)
  58 {
  59         return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
  60                 + KASAN_SHADOW_OFFSET;
  61 }
  62
  63 int kasan_add_zero_shadow(void *start, unsigned long size);
  64 void kasan_remove_zero_shadow(void *start, unsigned long size);
  65
  66 /* Enable reporting bugs after kasan_disable_current() */
  67 extern void kasan_enable_current(void);
  68
  69 /* Disable reporting bugs for current task */
  70 extern void kasan_disable_current(void);
  71
  72 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
  73
  74 static inline int kasan_add_zero_shadow(void *start, unsigned long size)
  75 {
  76         return 0;
  77 }
  78 static inline void kasan_remove_zero_shadow(void *start,
  79                                         unsigned long size)
  80 {}
  81
  82 static inline void kasan_enable_current(void) {}
  83 static inline void kasan_disable_current(void) {}
  84
  85 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
  86
  87 #ifdef CONFIG_KASAN_HW_TAGS
  88
  89 #else /* CONFIG_KASAN_HW_TAGS */
  90
  91 #endif /* CONFIG_KASAN_HW_TAGS */
  92
  93 static inline bool kasan_has_integrated_init(void)
  94 {
  95         return kasan_hw_tags_enabled();
  96 }
  97
  98 #ifdef CONFIG_KASAN
  99
 100 struct kasan_cache {
 101         int alloc_meta_offset;
 102         int free_meta_offset;
 103         bool is_kmalloc;
 104 };
 105
 106 slab_flags_t __kasan_never_merge(void);
 107 static __always_inline slab_flags_t kasan_never_merge(void)
 108 {
 109         if (kasan_enabled())
 110                 return __kasan_never_merge();
 111         return 0;
 112 }
 113
 114 void __kasan_unpoison_range(const void *addr, size_t size);
 115 static __always_inline void kasan_unpoison_range(const void *addr, size_t size)
 116 {
 117         if (kasan_enabled())
 118                 __kasan_unpoison_range(addr, size);
 119 }
 120
 121 void __kasan_poison_pages(struct page *page, unsigned int order, bool init);
 122 static __always_inline void kasan_poison_pages(struct page *page,
 123                                                 unsigned int order, bool init)
 124 {
 125         if (kasan_enabled())
 126                 __kasan_poison_pages(page, order, init);
 127 }
 128
 129 void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init);
 130 static __always_inline void kasan_unpoison_pages(struct page *page,
 131                                                  unsigned int order, bool init)
 132 {
 133         if (kasan_enabled())
 134                 __kasan_unpoison_pages(page, order, init);
 135 }
 136
 137 void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size,
 138                                 slab_flags_t *flags);
 139 static __always_inline void kasan_cache_create(struct kmem_cache *cache,
 140                                 unsigned int *size, slab_flags_t *flags)
 141 {
 142         if (kasan_enabled())
 143                 __kasan_cache_create(cache, size, flags);
 144 }
 145
 146 void __kasan_cache_create_kmalloc(struct kmem_cache *cache);
 147 static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache)
 148 {
 149         if (kasan_enabled())
 150                 __kasan_cache_create_kmalloc(cache);
 151 }
 152
 153 size_t __kasan_metadata_size(struct kmem_cache *cache);
 154 static __always_inline size_t kasan_metadata_size(struct kmem_cache *cache)
 155 {
 156         if (kasan_enabled())
 157                 return __kasan_metadata_size(cache);
 158         return 0;
 159 }
 160
 161 void __kasan_poison_slab(struct slab *slab);
 162 static __always_inline void kasan_poison_slab(struct slab *slab)
 163 {
 164         if (kasan_enabled())
 165                 __kasan_poison_slab(slab);
 166 }
 167
 168 void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object);
 169 static __always_inline void kasan_unpoison_object_data(struct kmem_cache *cache,
 170                                                         void *object)
 171 {
 172         if (kasan_enabled())
 173                 __kasan_unpoison_object_data(cache, object);
 174 }
 175
 176 void __kasan_poison_object_data(struct kmem_cache *cache, void *object);
 177 static __always_inline void kasan_poison_object_data(struct kmem_cache *cache,
 178                                                         void *object)
 179 {
 180         if (kasan_enabled())
 181                 __kasan_poison_object_data(cache, object);
 182 }
 183
 184 void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,
 185                                           const void *object);
 186 static __always_inline void * __must_check kasan_init_slab_obj(
 187                                 struct kmem_cache *cache, const void *object)
 188 {
 189         if (kasan_enabled())
 190                 return __kasan_init_slab_obj(cache, object);
 191         return (void *)object;
 192 }
 193
 194 bool __kasan_slab_free(struct kmem_cache *s, void *object,
 195                         unsigned long ip, bool init);
 196 static __always_inline bool kasan_slab_free(struct kmem_cache *s,
 197                                                 void *object, bool init)
 198 {
 199         if (kasan_enabled())
 200                 return __kasan_slab_free(s, object, _RET_IP_, init);
 201         return false;
 202 }
 203
 204 void __kasan_kfree_large(void *ptr, unsigned long ip);
 205 static __always_inline void kasan_kfree_large(void *ptr)
 206 {
 207         if (kasan_enabled())
 208                 __kasan_kfree_large(ptr, _RET_IP_);
 209 }
 210
 211 void __kasan_slab_free_mempool(void *ptr, unsigned long ip);
 212 static __always_inline void kasan_slab_free_mempool(void *ptr)
 213 {
 214         if (kasan_enabled())
 215                 __kasan_slab_free_mempool(ptr, _RET_IP_);
 216 }
 217
 218 void * __must_check __kasan_slab_alloc(struct kmem_cache *s,
 219                                        void *object, gfp_t flags, bool init);
 220 static __always_inline void * __must_check kasan_slab_alloc(
 221                 struct kmem_cache *s, void *object, gfp_t flags, bool init)
 222 {
 223         if (kasan_enabled())
 224                 return __kasan_slab_alloc(s, object, flags, init);
 225         return object;
 226 }
 227
 228 void * __must_check __kasan_kmalloc(struct kmem_cache *s, const void *object,
 229                                     size_t size, gfp_t flags);
 230 static __always_inline void * __must_check kasan_kmalloc(struct kmem_cache *s,
 231                                 const void *object, size_t size, gfp_t flags)
 232 {
 233         if (kasan_enabled())
 234                 return __kasan_kmalloc(s, object, size, flags);
 235         return (void *)object;
 236 }
 237
 238 void * __must_check __kasan_kmalloc_large(const void *ptr,
 239                                           size_t size, gfp_t flags);
 240 static __always_inline void * __must_check kasan_kmalloc_large(const void *ptr,
 241                                                       size_t size, gfp_t flags)
 242 {
 243         if (kasan_enabled())
 244                 return __kasan_kmalloc_large(ptr, size, flags);
 245         return (void *)ptr;
 246 }
 247
 248 void * __must_check __kasan_krealloc(const void *object,
 249                                      size_t new_size, gfp_t flags);
 250 static __always_inline void * __must_check kasan_krealloc(const void *object,
 251                                                  size_t new_size, gfp_t flags)
 252 {
 253         if (kasan_enabled())
 254                 return __kasan_krealloc(object, new_size, flags);
 255         return (void *)object;
 256 }
 257
 258 /*
 259  * Unlike kasan_check_read/write(), kasan_check_byte() is performed even for
 260  * the hardware tag-based mode that doesn't rely on compiler instrumentation.
 261  */
 262 bool __kasan_check_byte(const void *addr, unsigned long ip);
 263 static __always_inline bool kasan_check_byte(const void *addr)
 264 {
 265         if (kasan_enabled())
 266                 return __kasan_check_byte(addr, _RET_IP_);
 267         return true;
 268 }
 269
 270 #else /* CONFIG_KASAN */
 271
 272 static inline slab_flags_t kasan_never_merge(void)
 273 {
 274         return 0;
 275 }
 276 static inline void kasan_unpoison_range(const void *address, size_t size) {}
 277 static inline void kasan_poison_pages(struct page *page, unsigned int order,
 278                                       bool init) {}
 279 static inline void kasan_unpoison_pages(struct page *page, unsigned int order,
 280                                         bool init) {}
 281 static inline void kasan_cache_create(struct kmem_cache *cache,
 282                                       unsigned int *size,
 283                                       slab_flags_t *flags) {}
 284 static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {}
 285 static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; }
 286 static inline void kasan_poison_slab(struct slab *slab) {}
 287 static inline void kasan_unpoison_object_data(struct kmem_cache *cache,
 288                                         void *object) {}
 289 static inline void kasan_poison_object_data(struct kmem_cache *cache,
 290                                         void *object) {}
 291 static inline void *kasan_init_slab_obj(struct kmem_cache *cache,
 292                                 const void *object)
 293 {
 294         return (void *)object;
 295 }
 296 static inline bool kasan_slab_free(struct kmem_cache *s, void *object, bool init)
 297 {
 298         return false;
 299 }
 300 static inline void kasan_kfree_large(void *ptr) {}
 301 static inline void kasan_slab_free_mempool(void *ptr) {}
 302 static inline void *kasan_slab_alloc(struct kmem_cache *s, void *object,
 303                                    gfp_t flags, bool init)
 304 {
 305         return object;
 306 }
 307 static inline void *kasan_kmalloc(struct kmem_cache *s, const void *object,
 308                                 size_t size, gfp_t flags)
 309 {
 310         return (void *)object;
 311 }
 312 static inline void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags)
 313 {
 314         return (void *)ptr;
 315 }
 316 static inline void *kasan_krealloc(const void *object, size_t new_size,
 317                                  gfp_t flags)
 318 {
 319         return (void *)object;
 320 }
 321 static inline bool kasan_check_byte(const void *address)
 322 {
 323         return true;
 324 }
 325
 326 #endif /* CONFIG_KASAN */
 327
 328 #if defined(CONFIG_KASAN) && defined(CONFIG_KASAN_STACK)
 329 void kasan_unpoison_task_stack(struct task_struct *task);
 330 #else
 331 static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
 332 #endif
 333
 334 #ifdef CONFIG_KASAN_GENERIC
 335
 336 void kasan_cache_shrink(struct kmem_cache *cache);
 337 void kasan_cache_shutdown(struct kmem_cache *cache);
 338 void kasan_record_aux_stack(void *ptr);
 339 void kasan_record_aux_stack_noalloc(void *ptr);
 340
 341 #else /* CONFIG_KASAN_GENERIC */
 342
 343 static inline void kasan_cache_shrink(struct kmem_cache *cache) {}
 344 static inline void kasan_cache_shutdown(struct kmem_cache *cache) {}
 345 static inline void kasan_record_aux_stack(void *ptr) {}
 346 static inline void kasan_record_aux_stack_noalloc(void *ptr) {}
 347
 348 #endif /* CONFIG_KASAN_GENERIC */
 349
 350 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
 351
 352 static inline void *kasan_reset_tag(const void *addr)
 353 {
 354         return (void *)arch_kasan_reset_tag(addr);
 355 }
 356
 357 /**
 358  * kasan_report - print a report about a bad memory access detected by KASAN
 359  * @addr: address of the bad access
 360  * @size: size of the bad access
 361  * @is_write: whether the bad access is a write or a read
 362  * @ip: instruction pointer for the accessibility check or the bad access itself
 363  */
 364 bool kasan_report(unsigned long addr, size_t size,
 365                 bool is_write, unsigned long ip);
 366
 367 #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
 368
 369 static inline void *kasan_reset_tag(const void *addr)
 370 {
 371         return (void *)addr;
 372 }
 373
 374 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/
 375
 376 #ifdef CONFIG_KASAN_HW_TAGS
 377
 378 void kasan_report_async(void);
 379
 380 #endif /* CONFIG_KASAN_HW_TAGS */
 381
 382 #ifdef CONFIG_KASAN_SW_TAGS
 383 void __init kasan_init_sw_tags(void);
 384 #else
 385 static inline void kasan_init_sw_tags(void) { }
 386 #endif
 387
 388 #ifdef CONFIG_KASAN_HW_TAGS
 389 void kasan_init_hw_tags_cpu(void);
 390 void __init kasan_init_hw_tags(void);
 391 #else
 392 static inline void kasan_init_hw_tags_cpu(void) { }
 393 static inline void kasan_init_hw_tags(void) { }
 394 #endif
 395
 396 #ifdef CONFIG_KASAN_VMALLOC
 397
 398 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 399
 400 void kasan_populate_early_vm_area_shadow(void *start, unsigned long size);
 401 int kasan_populate_vmalloc(unsigned long addr, unsigned long size);
 402 void kasan_release_vmalloc(unsigned long start, unsigned long end,
 403                            unsigned long free_region_start,
 404                            unsigned long free_region_end);
 405
 406 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
 407
 408 static inline void kasan_populate_early_vm_area_shadow(void *start,
 409                                                        unsigned long size)
 410 { }
 411 static inline int kasan_populate_vmalloc(unsigned long start,
 412                                         unsigned long size)
 413 {
 414         return 0;
 415 }
 416 static inline void kasan_release_vmalloc(unsigned long start,
 417                                          unsigned long end,
 418                                          unsigned long free_region_start,
 419                                          unsigned long free_region_end) { }
 420
 421 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
 422
 423 void *__kasan_unpoison_vmalloc(const void *start, unsigned long size,
 424                                kasan_vmalloc_flags_t flags);
 425 static __always_inline void *kasan_unpoison_vmalloc(const void *start,
 426                                                 unsigned long size,
 427                                                 kasan_vmalloc_flags_t flags)
 428 {
 429         if (kasan_enabled())
 430                 return __kasan_unpoison_vmalloc(start, size, flags);
 431         return (void *)start;
 432 }
 433
 434 void __kasan_poison_vmalloc(const void *start, unsigned long size);
 435 static __always_inline void kasan_poison_vmalloc(const void *start,
 436                                                  unsigned long size)
 437 {
 438         if (kasan_enabled())
 439                 __kasan_poison_vmalloc(start, size);
 440 }
 441
 442 #else /* CONFIG_KASAN_VMALLOC */
 443
 444 static inline void kasan_populate_early_vm_area_shadow(void *start,
 445                                                        unsigned long size) { }
 446 static inline int kasan_populate_vmalloc(unsigned long start,
 447                                         unsigned long size)
 448 {
 449         return 0;
 450 }
 451 static inline void kasan_release_vmalloc(unsigned long start,
 452                                          unsigned long end,
 453                                          unsigned long free_region_start,
 454                                          unsigned long free_region_end) { }
 455
 456 static inline void *kasan_unpoison_vmalloc(const void *start,
 457                                            unsigned long size,
 458                                            kasan_vmalloc_flags_t flags)
 459 {
 460         return (void *)start;
 461 }
 462 static inline void kasan_poison_vmalloc(const void *start, unsigned long size)
 463 { }
 464
 465 #endif /* CONFIG_KASAN_VMALLOC */
 466
 467 #if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
 468                 !defined(CONFIG_KASAN_VMALLOC)
 469
 470 /*
 471  * These functions allocate and free shadow memory for kernel modules.
 472  * They are only required when KASAN_VMALLOC is not supported, as otherwise
 473  * shadow memory is allocated by the generic vmalloc handlers.
 474  */
 475 int kasan_alloc_module_shadow(void *addr, size_t size, gfp_t gfp_mask);
 476 void kasan_free_module_shadow(const struct vm_struct *vm);
 477
 478 #else /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
 479
 480 static inline int kasan_alloc_module_shadow(void *addr, size_t size, gfp_t gfp_mask) { return 0; }
 481 static inline void kasan_free_module_shadow(const struct vm_struct *vm) {}
 482
 483 #endif /* (CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) && !CONFIG_KASAN_VMALLOC */
 484
 485 #ifdef CONFIG_KASAN_INLINE
 486 void kasan_non_canonical_hook(unsigned long addr);
 487 #else /* CONFIG_KASAN_INLINE */
 488 static inline void kasan_non_canonical_hook(unsigned long addr) { }
 489 #endif /* CONFIG_KASAN_INLINE */
 490
 491 #endif /* LINUX_KASAN_H */