LXR linux/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
  15DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
  16extern bool kasan_flag_async __ro_after_init;
  17
  18static inline bool kasan_stack_collection_enabled(void)
  19{
  20        return static_branch_unlikely(&kasan_flag_stacktrace);
  21}
  22
  23static inline bool kasan_async_mode_enabled(void)
  24{
  25        return kasan_flag_async;
  26}
  27#else
  28
  29static inline bool kasan_stack_collection_enabled(void)
  30{
  31        return true;
  32}
  33
  34static inline bool kasan_async_mode_enabled(void)
  35{
  36        return false;
  37}
  38
  39#endif
  40
  41extern 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
 105struct 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 */
 114struct 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 */
 121struct 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
 142struct 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
 153struct 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
 170struct 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
 182struct 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
 192struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
 193                                                const void *object);
 194#ifdef CONFIG_KASAN_GENERIC
 195struct 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
 201static 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
 207static 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 */
 220bool 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
 225static 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)
 233void kasan_print_tags(u8 addr_tag, const void *addr);
 234#else
 235static inline void kasan_print_tags(u8 addr_tag, const void *addr) { }
 236#endif
 237
 238void *kasan_find_first_bad_addr(void *addr, size_t size);
 239const char *kasan_get_bug_type(struct kasan_access_info *info);
 240void kasan_metadata_fetch_row(char *buffer, void *row);
 241
 242#if defined(CONFIG_KASAN_GENERIC) && defined(CONFIG_KASAN_STACK)
 243void kasan_print_address_stack_frame(const void *addr);
 244#else
 245static inline void kasan_print_address_stack_frame(const void *addr) { }
 246#endif
 247
 248bool kasan_report(unsigned long addr, size_t size,
 249                bool is_write, unsigned long ip);
 250void kasan_report_invalid_free(void *object, unsigned long ip);
 251
 252struct page *kasan_addr_to_page(const void *addr);
 253
 254depot_stack_handle_t kasan_save_stack(gfp_t flags);
 255void kasan_set_track(struct kasan_track *track, gfp_t flags);
 256void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
 257struct 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))
 262bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
 263void kasan_quarantine_reduce(void);
 264void kasan_quarantine_remove_cache(struct kmem_cache *cache);
 265#else
 266static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; }
 267static inline void kasan_quarantine_reduce(void) { }
 268static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { }
 269#endif
 270
 271#ifndef arch_kasan_set_tag
 272static 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
 322void kasan_enable_tagging_sync(void);
 323void kasan_force_async_fault(void);
 324
 325#else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */
 326
 327static inline void kasan_enable_tagging_sync(void) { }
 328static 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
 333u8 kasan_random_tag(void);
 334#elif defined(CONFIG_KASAN_HW_TAGS)
 335static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); }
 336#else
 337static inline u8 kasan_random_tag(void) { return 0; }
 338#endif
 339
 340#ifdef CONFIG_KASAN_HW_TAGS
 341
 342static 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
 358static 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
 386static 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 */
 405void 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 */
 418void kasan_unpoison(const void *addr, size_t size, bool init);
 419
 420bool 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 */
 435void kasan_poison_last_granule(const void *address, size_t size);
 436
 437#else /* CONFIG_KASAN_GENERIC */
 438
 439static 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
 444static 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 */
 453asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
 454void __asan_register_globals(struct kasan_global *globals, size_t size);
 455void __asan_unregister_globals(struct kasan_global *globals, size_t size);
 456void __asan_handle_no_return(void);
 457void __asan_alloca_poison(unsigned long addr, size_t size);
 458void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
 459
 460void __asan_load1(unsigned long addr);
 461void __asan_store1(unsigned long addr);
 462void __asan_load2(unsigned long addr);
 463void __asan_store2(unsigned long addr);
 464void __asan_load4(unsigned long addr);
 465void __asan_store4(unsigned long addr);
 466void __asan_load8(unsigned long addr);
 467void __asan_store8(unsigned long addr);
 468void __asan_load16(unsigned long addr);
 469void __asan_store16(unsigned long addr);
 470void __asan_loadN(unsigned long addr, size_t size);
 471void __asan_storeN(unsigned long addr, size_t size);
 472
 473void __asan_load1_noabort(unsigned long addr);
 474void __asan_store1_noabort(unsigned long addr);
 475void __asan_load2_noabort(unsigned long addr);
 476void __asan_store2_noabort(unsigned long addr);
 477void __asan_load4_noabort(unsigned long addr);
 478void __asan_store4_noabort(unsigned long addr);
 479void __asan_load8_noabort(unsigned long addr);
 480void __asan_store8_noabort(unsigned long addr);
 481void __asan_load16_noabort(unsigned long addr);
 482void __asan_store16_noabort(unsigned long addr);
 483void __asan_loadN_noabort(unsigned long addr, size_t size);
 484void __asan_storeN_noabort(unsigned long addr, size_t size);
 485
 486void __asan_report_load1_noabort(unsigned long addr);
 487void __asan_report_store1_noabort(unsigned long addr);
 488void __asan_report_load2_noabort(unsigned long addr);
 489void __asan_report_store2_noabort(unsigned long addr);
 490void __asan_report_load4_noabort(unsigned long addr);
 491void __asan_report_store4_noabort(unsigned long addr);
 492void __asan_report_load8_noabort(unsigned long addr);
 493void __asan_report_store8_noabort(unsigned long addr);
 494void __asan_report_load16_noabort(unsigned long addr);
 495void __asan_report_store16_noabort(unsigned long addr);
 496void __asan_report_load_n_noabort(unsigned long addr, size_t size);
 497void __asan_report_store_n_noabort(unsigned long addr, size_t size);
 498
 499void __asan_set_shadow_00(const void *addr, size_t size);
 500void __asan_set_shadow_f1(const void *addr, size_t size);
 501void __asan_set_shadow_f2(const void *addr, size_t size);
 502void __asan_set_shadow_f3(const void *addr, size_t size);
 503void __asan_set_shadow_f5(const void *addr, size_t size);
 504void __asan_set_shadow_f8(const void *addr, size_t size);
 505
 506void __hwasan_load1_noabort(unsigned long addr);
 507void __hwasan_store1_noabort(unsigned long addr);
 508void __hwasan_load2_noabort(unsigned long addr);
 509void __hwasan_store2_noabort(unsigned long addr);
 510void __hwasan_load4_noabort(unsigned long addr);
 511void __hwasan_store4_noabort(unsigned long addr);
 512void __hwasan_load8_noabort(unsigned long addr);
 513void __hwasan_store8_noabort(unsigned long addr);
 514void __hwasan_load16_noabort(unsigned long addr);
 515void __hwasan_store16_noabort(unsigned long addr);
 516void __hwasan_loadN_noabort(unsigned long addr, size_t size);
 517void __hwasan_storeN_noabort(unsigned long addr, size_t size);
 518
 519void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
 520
 521#endif
 522