mm/kasan/kasan.h

   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/kasan-tags.h>
   7 #include <linux/kfence.h>
   8 #include <linux/stackdepot.h>
   9
  10 #ifdef CONFIG_KASAN_HW_TAGS
  11
  12 #include <linux/static_key.h>
  13 #include "../slab.h"
  14
  15 DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
  16 extern bool kasan_flag_async __ro_after_init;
  17
  18 static inline bool kasan_stack_collection_enabled(void)
  19 {
  20         return static_branch_unlikely(&kasan_flag_stacktrace);
  21 }
  22
  23 static inline bool kasan_async_mode_enabled(void)
  24 {
  25         return kasan_flag_async;
  26 }
  27 #else
  28
  29 static inline bool kasan_stack_collection_enabled(void)
  30 {
  31         return true;
  32 }
  33
  34 static inline bool kasan_async_mode_enabled(void)
  35 {
  36         return false;
  37 }
  38
  39 #endif
  40
  41 extern bool kasan_flag_async __ro_after_init;
  42
  43 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
  44 #define KASAN_GRANULE_SIZE      (1UL << KASAN_SHADOW_SCALE_SHIFT)
  45 #else
  46 #include <asm/mte-kasan.h>
  47 #define KASAN_GRANULE_SIZE      MTE_GRANULE_SIZE
  48 #endif
  49
  50 #define KASAN_GRANULE_MASK      (KASAN_GRANULE_SIZE - 1)
  51
  52 #define KASAN_MEMORY_PER_SHADOW_PAGE    (KASAN_GRANULE_SIZE << PAGE_SHIFT)
  53
  54 #ifdef CONFIG_KASAN_GENERIC
  55 #define KASAN_FREE_PAGE         0xFF  /* page was freed */
  56 #define KASAN_PAGE_REDZONE      0xFE  /* redzone for kmalloc_large allocations */
  57 #define KASAN_KMALLOC_REDZONE   0xFC  /* redzone inside slub object */
  58 #define KASAN_KMALLOC_FREE      0xFB  /* object was freed (kmem_cache_free/kfree) */
  59 #define KASAN_KMALLOC_FREETRACK 0xFA  /* object was freed and has free track set */
  60 #else
  61 #define KASAN_FREE_PAGE         KASAN_TAG_INVALID
  62 #define KASAN_PAGE_REDZONE      KASAN_TAG_INVALID
  63 #define KASAN_KMALLOC_REDZONE   KASAN_TAG_INVALID
  64 #define KASAN_KMALLOC_FREE      KASAN_TAG_INVALID
  65 #define KASAN_KMALLOC_FREETRACK KASAN_TAG_INVALID
  66 #endif
  67
  68 #define KASAN_GLOBAL_REDZONE    0xF9  /* redzone for global variable */
  69 #define KASAN_VMALLOC_INVALID   0xF8  /* unallocated space in vmapped page */
  70
  71 /*
  72  * Stack redzone shadow values
  73  * (Those are compiler's ABI, don't change them)
  74  */
  75 #define KASAN_STACK_LEFT        0xF1
  76 #define KASAN_STACK_MID         0xF2
  77 #define KASAN_STACK_RIGHT       0xF3
  78 #define KASAN_STACK_PARTIAL     0xF4
  79
  80 /*
  81  * alloca redzone shadow values
  82  */
  83 #define KASAN_ALLOCA_LEFT       0xCA
  84 #define KASAN_ALLOCA_RIGHT      0xCB
  85
  86 #define KASAN_ALLOCA_REDZONE_SIZE       32
  87
  88 /*
  89  * Stack frame marker (compiler ABI).
  90  */
  91 #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3
  92
  93 /* Don't break randconfig/all*config builds */
  94 #ifndef KASAN_ABI_VERSION
  95 #define KASAN_ABI_VERSION 1
  96 #endif
  97
  98 /* Metadata layout customization. */
  99 #define META_BYTES_PER_BLOCK 1
 100 #define META_BLOCKS_PER_ROW 16
 101 #define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
 102 #define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
 103 #define META_ROWS_AROUND_ADDR 2
 104
 105 struct kasan_access_info {
 106         const void *access_addr;
 107         const void *first_bad_addr;
 108         size_t access_size;
 109         bool is_write;
 110         unsigned long ip;
 111 };
 112
 113 /* The layout of struct dictated by compiler */
 114 struct kasan_source_location {
 115         const char *filename;
 116         int line_no;
 117         int column_no;
 118 };
 119
 120 /* The layout of struct dictated by compiler */
 121 struct kasan_global {
 122         const void *beg;                /* Address of the beginning of the global variable. */
 123         size_t size;                    /* Size of the global variable. */
 124         size_t size_with_redzone;       /* Size of the variable + size of the red zone. 32 bytes aligned */
 125         const void *name;
 126         const void *module_name;        /* Name of the module where the global variable is declared. */
 127         unsigned long has_dynamic_init; /* This needed for C++ */
 128 #if KASAN_ABI_VERSION >= 4
 129         struct kasan_source_location *location;
 130 #endif
 131 #if KASAN_ABI_VERSION >= 5
 132         char *odr_indicator;
 133 #endif
 134 };
 135
 136 /**
 137  * Structures to keep alloc and free tracks *
 138  */
 139
 140 #define KASAN_STACK_DEPTH 64
 141
 142 struct kasan_track {
 143         u32 pid;
 144         depot_stack_handle_t stack;
 145 };
 146
 147 #if defined(CONFIG_KASAN_TAGS_IDENTIFY) && defined(CONFIG_KASAN_SW_TAGS)
 148 #define KASAN_NR_FREE_STACKS 5
 149 #else
 150 #define KASAN_NR_FREE_STACKS 1
 151 #endif
 152
 153 struct kasan_alloc_meta {
 154         struct kasan_track alloc_track;
 155 #ifdef CONFIG_KASAN_GENERIC
 156         /*
 157          * The auxiliary stack is stored into struct kasan_alloc_meta.
 158          * The free stack is stored into struct kasan_free_meta.
 159          */
 160         depot_stack_handle_t aux_stack[2];
 161 #else
 162         struct kasan_track free_track[KASAN_NR_FREE_STACKS];
 163 #endif
 164 #ifdef CONFIG_KASAN_TAGS_IDENTIFY
 165         u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
 166         u8 free_track_idx;
 167 #endif
 168 };
 169
 170 struct qlist_node {
 171         struct qlist_node *next;
 172 };
 173
 174 /*
 175  * Generic mode either stores free meta in the object itself or in the redzone
 176  * after the object. In the former case free meta offset is 0, in the latter
 177  * case it has some sane value smaller than INT_MAX. Use INT_MAX as free meta
 178  * offset when free meta isn't present.
 179  */
 180 #define KASAN_NO_FREE_META INT_MAX
 181
 182 struct kasan_free_meta {
 183 #ifdef CONFIG_KASAN_GENERIC
 184         /* This field is used while the object is in the quarantine.
 185          * Otherwise it might be used for the allocator freelist.
 186          */
 187         struct qlist_node quarantine_link;
 188         struct kasan_track free_track;
 189 #endif
 190 };
 191
 192 struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
 193                                                 const void *object);
 194 #ifdef CONFIG_KASAN_GENERIC
 195 struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
 196                                                 const void *object);
 197 #endif
 198
 199 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 200
 201 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
 202 {
 203         return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
 204                 << KASAN_SHADOW_SCALE_SHIFT);
 205 }
 206
 207 static inline bool addr_has_metadata(const void *addr)
 208 {
 209         return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
 210 }
 211
 212 /**
 213  * kasan_check_range - Check memory region, and report if invalid access.
 214  * @addr: the accessed address
 215  * @size: the accessed size
 216  * @write: true if access is a write access
 217  * @ret_ip: return address
 218  * @return: true if access was valid, false if invalid
 219  */
 220 bool kasan_check_range(unsigned long addr, size_t size, bool write,
 221                                 unsigned long ret_ip);
 222
 223 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
 224
 225 static inline bool addr_has_metadata(const void *addr)
 226 {
 227         return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
 228 }
 229
 230 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
 231
 232 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
 233 void kasan_print_tags(u8 addr_tag, const void *addr);
 234 #else
 235 static inline void kasan_print_tags(u8 addr_tag, const void *addr) { }
 236 #endif
 237
 238 void *kasan_find_first_bad_addr(void *addr, size_t size);
 239 const char *kasan_get_bug_type(struct kasan_access_info *info);
 240 void kasan_metadata_fetch_row(char *buffer, void *row);
 241
 242 #if defined(CONFIG_KASAN_GENERIC) && defined(CONFIG_KASAN_STACK)
 243 void kasan_print_address_stack_frame(const void *addr);
 244 #else
 245 static inline void kasan_print_address_stack_frame(const void *addr) { }
 246 #endif
 247
 248 bool kasan_report(unsigned long addr, size_t size,
 249                 bool is_write, unsigned long ip);
 250 void kasan_report_invalid_free(void *object, unsigned long ip);
 251
 252 struct page *kasan_addr_to_page(const void *addr);
 253
 254 depot_stack_handle_t kasan_save_stack(gfp_t flags);
 255 void kasan_set_track(struct kasan_track *track, gfp_t flags);
 256 void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
 257 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
 258                                 void *object, u8 tag);
 259
 260 #if defined(CONFIG_KASAN_GENERIC) && \
 261         (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
 262 bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
 263 void kasan_quarantine_reduce(void);
 264 void kasan_quarantine_remove_cache(struct kmem_cache *cache);
 265 #else
 266 static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; }
 267 static inline void kasan_quarantine_reduce(void) { }
 268 static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { }
 269 #endif
 270
 271 #ifndef arch_kasan_set_tag
 272 static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 273 {
 274         return addr;
 275 }
 276 #endif
 277 #ifndef arch_kasan_get_tag
 278 #define arch_kasan_get_tag(addr)        0
 279 #endif
 280
 281 #define set_tag(addr, tag)      ((void *)arch_kasan_set_tag((addr), (tag)))
 282 #define get_tag(addr)           arch_kasan_get_tag(addr)
 283
 284 #ifdef CONFIG_KASAN_HW_TAGS
 285
 286 #ifndef arch_enable_tagging_sync
 287 #define arch_enable_tagging_sync()
 288 #endif
 289 #ifndef arch_enable_tagging_async
 290 #define arch_enable_tagging_async()
 291 #endif
 292 #ifndef arch_force_async_tag_fault
 293 #define arch_force_async_tag_fault()
 294 #endif
 295 #ifndef arch_get_random_tag
 296 #define arch_get_random_tag()   (0xFF)
 297 #endif
 298 #ifndef arch_get_mem_tag
 299 #define arch_get_mem_tag(addr)  (0xFF)
 300 #endif
 301 #ifndef arch_set_mem_tag_range
 302 #define arch_set_mem_tag_range(addr, size, tag, init) ((void *)(addr))
 303 #endif
 304
 305 #define hw_enable_tagging_sync()                arch_enable_tagging_sync()
 306 #define hw_enable_tagging_async()               arch_enable_tagging_async()
 307 #define hw_force_async_tag_fault()              arch_force_async_tag_fault()
 308 #define hw_get_random_tag()                     arch_get_random_tag()
 309 #define hw_get_mem_tag(addr)                    arch_get_mem_tag(addr)
 310 #define hw_set_mem_tag_range(addr, size, tag, init) \
 311                         arch_set_mem_tag_range((addr), (size), (tag), (init))
 312
 313 #else /* CONFIG_KASAN_HW_TAGS */
 314
 315 #define hw_enable_tagging_sync()
 316 #define hw_enable_tagging_async()
 317
 318 #endif /* CONFIG_KASAN_HW_TAGS */
 319
 320 #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
 321
 322 void kasan_enable_tagging_sync(void);
 323 void kasan_force_async_fault(void);
 324
 325 #else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */
 326
 327 static inline void kasan_enable_tagging_sync(void) { }
 328 static inline void kasan_force_async_fault(void) { }
 329
 330 #endif /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */
 331
 332 #ifdef CONFIG_KASAN_SW_TAGS
 333 u8 kasan_random_tag(void);
 334 #elif defined(CONFIG_KASAN_HW_TAGS)
 335 static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); }
 336 #else
 337 static inline u8 kasan_random_tag(void) { return 0; }
 338 #endif
 339
 340 #ifdef CONFIG_KASAN_HW_TAGS
 341
 342 static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
 343 {
 344         addr = kasan_reset_tag(addr);
 345
 346         /* Skip KFENCE memory if called explicitly outside of sl*b. */
 347         if (is_kfence_address(addr))
 348                 return;
 349
 350         if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
 351                 return;
 352         if (WARN_ON(size & KASAN_GRANULE_MASK))
 353                 return;
 354
 355         hw_set_mem_tag_range((void *)addr, size, value, init);
 356 }
 357
 358 static inline void kasan_unpoison(const void *addr, size_t size, bool init)
 359 {
 360         u8 tag = get_tag(addr);
 361
 362         addr = kasan_reset_tag(addr);
 363
 364         /* Skip KFENCE memory if called explicitly outside of sl*b. */
 365         if (is_kfence_address(addr))
 366                 return;
 367
 368         if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
 369                 return;
 370         /*
 371          * Explicitly initialize the memory with the precise object size to
 372          * avoid overwriting the SLAB redzone. This disables initialization in
 373          * the arch code and may thus lead to performance penalty. The penalty
 374          * is accepted since SLAB redzones aren't enabled in production builds.
 375          */
 376         if (__slub_debug_enabled() &&
 377             init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
 378                 init = false;
 379                 memzero_explicit((void *)addr, size);
 380         }
 381         size = round_up(size, KASAN_GRANULE_SIZE);
 382
 383         hw_set_mem_tag_range((void *)addr, size, tag, init);
 384 }
 385
 386 static inline bool kasan_byte_accessible(const void *addr)
 387 {
 388         u8 ptr_tag = get_tag(addr);
 389         u8 mem_tag = hw_get_mem_tag((void *)addr);
 390
 391         return ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag;
 392 }
 393
 394 #else /* CONFIG_KASAN_HW_TAGS */
 395
 396 /**
 397  * kasan_poison - mark the memory range as inaccessible
 398  * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
 399  * @size - range size, must be aligned to KASAN_GRANULE_SIZE
 400  * @value - value that's written to metadata for the range
 401  * @init - whether to initialize the memory range (only for hardware tag-based)
 402  *
 403  * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
 404  */
 405 void kasan_poison(const void *addr, size_t size, u8 value, bool init);
 406
 407 /**
 408  * kasan_unpoison - mark the memory range as accessible
 409  * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
 410  * @size - range size, can be unaligned
 411  * @init - whether to initialize the memory range (only for hardware tag-based)
 412  *
 413  * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before
 414  * marking the range.
 415  * For the generic mode, the last granule of the memory range gets partially
 416  * unpoisoned based on the @size.
 417  */
 418 void kasan_unpoison(const void *addr, size_t size, bool init);
 419
 420 bool kasan_byte_accessible(const void *addr);
 421
 422 #endif /* CONFIG_KASAN_HW_TAGS */
 423
 424 #ifdef CONFIG_KASAN_GENERIC
 425
 426 /**
 427  * kasan_poison_last_granule - mark the last granule of the memory range as
 428  * inaccessible
 429  * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
 430  * @size - range size
 431  *
 432  * This function is only available for the generic mode, as it's the only mode
 433  * that has partially poisoned memory granules.
 434  */
 435 void kasan_poison_last_granule(const void *address, size_t size);
 436
 437 #else /* CONFIG_KASAN_GENERIC */
 438
 439 static inline void kasan_poison_last_granule(const void *address, size_t size) { }
 440
 441 #endif /* CONFIG_KASAN_GENERIC */
 442
 443 #ifndef kasan_arch_is_ready
 444 static inline bool kasan_arch_is_ready(void)    { return true; }
 445 #elif !defined(CONFIG_KASAN_GENERIC) || !defined(CONFIG_KASAN_OUTLINE)
 446 #error kasan_arch_is_ready only works in KASAN generic outline mode!
 447 #endif
 448
 449 /*
 450  * Exported functions for interfaces called from assembly or from generated
 451  * code. Declarations here to avoid warning about missing declarations.
 452  */
 453 asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
 454 void __asan_register_globals(struct kasan_global *globals, size_t size);
 455 void __asan_unregister_globals(struct kasan_global *globals, size_t size);
 456 void __asan_handle_no_return(void);
 457 void __asan_alloca_poison(unsigned long addr, size_t size);
 458 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
 459
 460 void __asan_load1(unsigned long addr);
 461 void __asan_store1(unsigned long addr);
 462 void __asan_load2(unsigned long addr);
 463 void __asan_store2(unsigned long addr);
 464 void __asan_load4(unsigned long addr);
 465 void __asan_store4(unsigned long addr);
 466 void __asan_load8(unsigned long addr);
 467 void __asan_store8(unsigned long addr);
 468 void __asan_load16(unsigned long addr);
 469 void __asan_store16(unsigned long addr);
 470 void __asan_loadN(unsigned long addr, size_t size);
 471 void __asan_storeN(unsigned long addr, size_t size);
 472
 473 void __asan_load1_noabort(unsigned long addr);
 474 void __asan_store1_noabort(unsigned long addr);
 475 void __asan_load2_noabort(unsigned long addr);
 476 void __asan_store2_noabort(unsigned long addr);
 477 void __asan_load4_noabort(unsigned long addr);
 478 void __asan_store4_noabort(unsigned long addr);
 479 void __asan_load8_noabort(unsigned long addr);
 480 void __asan_store8_noabort(unsigned long addr);
 481 void __asan_load16_noabort(unsigned long addr);
 482 void __asan_store16_noabort(unsigned long addr);
 483 void __asan_loadN_noabort(unsigned long addr, size_t size);
 484 void __asan_storeN_noabort(unsigned long addr, size_t size);
 485
 486 void __asan_report_load1_noabort(unsigned long addr);
 487 void __asan_report_store1_noabort(unsigned long addr);
 488 void __asan_report_load2_noabort(unsigned long addr);
 489 void __asan_report_store2_noabort(unsigned long addr);
 490 void __asan_report_load4_noabort(unsigned long addr);
 491 void __asan_report_store4_noabort(unsigned long addr);
 492 void __asan_report_load8_noabort(unsigned long addr);
 493 void __asan_report_store8_noabort(unsigned long addr);
 494 void __asan_report_load16_noabort(unsigned long addr);
 495 void __asan_report_store16_noabort(unsigned long addr);
 496 void __asan_report_load_n_noabort(unsigned long addr, size_t size);
 497 void __asan_report_store_n_noabort(unsigned long addr, size_t size);
 498
 499 void __asan_set_shadow_00(const void *addr, size_t size);
 500 void __asan_set_shadow_f1(const void *addr, size_t size);
 501 void __asan_set_shadow_f2(const void *addr, size_t size);
 502 void __asan_set_shadow_f3(const void *addr, size_t size);
 503 void __asan_set_shadow_f5(const void *addr, size_t size);
 504 void __asan_set_shadow_f8(const void *addr, size_t size);
 505
 506 void __hwasan_load1_noabort(unsigned long addr);
 507 void __hwasan_store1_noabort(unsigned long addr);
 508 void __hwasan_load2_noabort(unsigned long addr);
 509 void __hwasan_store2_noabort(unsigned long addr);
 510 void __hwasan_load4_noabort(unsigned long addr);
 511 void __hwasan_store4_noabort(unsigned long addr);
 512 void __hwasan_load8_noabort(unsigned long addr);
 513 void __hwasan_store8_noabort(unsigned long addr);
 514 void __hwasan_load16_noabort(unsigned long addr);
 515 void __hwasan_store16_noabort(unsigned long addr);
 516 void __hwasan_loadN_noabort(unsigned long addr, size_t size);
 517 void __hwasan_storeN_noabort(unsigned long addr, size_t size);
 518
 519 void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
 520
 521 #endif