diff options
Diffstat (limited to 'mm/kasan/kasan.c')
-rw-r--r-- | mm/kasan/kasan.c | 343 |
1 files changed, 0 insertions, 343 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c deleted file mode 100644 index 44ec228de0a2..000000000000 --- a/mm/kasan/kasan.c +++ /dev/null @@ -1,343 +0,0 @@ -/* - * This file contains core KASAN code. - * - * Copyright (c) 2014 Samsung Electronics Co., Ltd. - * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> - * - * Some code borrowed from https://github.com/xairy/kasan-prototype by - * Andrey Konovalov <andreyknvl@gmail.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#define DISABLE_BRANCH_PROFILING - -#include <linux/export.h> -#include <linux/interrupt.h> -#include <linux/init.h> -#include <linux/kasan.h> -#include <linux/kernel.h> -#include <linux/kmemleak.h> -#include <linux/linkage.h> -#include <linux/memblock.h> -#include <linux/memory.h> -#include <linux/mm.h> -#include <linux/module.h> -#include <linux/printk.h> -#include <linux/sched.h> -#include <linux/sched/task_stack.h> -#include <linux/slab.h> -#include <linux/stacktrace.h> -#include <linux/string.h> -#include <linux/types.h> -#include <linux/vmalloc.h> -#include <linux/bug.h> - -#include "kasan.h" -#include "../slab.h" - -/* - * All functions below always inlined so compiler could - * perform better optimizations in each of __asan_loadX/__assn_storeX - * depending on memory access size X. - */ - -static __always_inline bool memory_is_poisoned_1(unsigned long addr) -{ - s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr); - - if (unlikely(shadow_value)) { - s8 last_accessible_byte = addr & KASAN_SHADOW_MASK; - return unlikely(last_accessible_byte >= shadow_value); - } - - return false; -} - -static __always_inline bool memory_is_poisoned_2_4_8(unsigned long addr, - unsigned long size) -{ - u8 *shadow_addr = (u8 *)kasan_mem_to_shadow((void *)addr); - - /* - * Access crosses 8(shadow size)-byte boundary. Such access maps - * into 2 shadow bytes, so we need to check them both. - */ - if (unlikely(((addr + size - 1) & KASAN_SHADOW_MASK) < size - 1)) - return *shadow_addr || memory_is_poisoned_1(addr + size - 1); - - return memory_is_poisoned_1(addr + size - 1); -} - -static __always_inline bool memory_is_poisoned_16(unsigned long addr) -{ - u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr); - - /* Unaligned 16-bytes access maps into 3 shadow bytes. */ - if (unlikely(!IS_ALIGNED(addr, KASAN_SHADOW_SCALE_SIZE))) - return *shadow_addr || memory_is_poisoned_1(addr + 15); - - return *shadow_addr; -} - -static __always_inline unsigned long bytes_is_nonzero(const u8 *start, - size_t size) -{ - while (size) { - if (unlikely(*start)) - return (unsigned long)start; - start++; - size--; - } - - return 0; -} - -static __always_inline unsigned long memory_is_nonzero(const void *start, - const void *end) -{ - unsigned int words; - unsigned long ret; - unsigned int prefix = (unsigned long)start % 8; - - if (end - start <= 16) - return bytes_is_nonzero(start, end - start); - - if (prefix) { - prefix = 8 - prefix; - ret = bytes_is_nonzero(start, prefix); - if (unlikely(ret)) - return ret; - start += prefix; - } - - words = (end - start) / 8; - while (words) { - if (unlikely(*(u64 *)start)) - return bytes_is_nonzero(start, 8); - start += 8; - words--; - } - - return bytes_is_nonzero(start, (end - start) % 8); -} - -static __always_inline bool memory_is_poisoned_n(unsigned long addr, - size_t size) -{ - unsigned long ret; - - ret = memory_is_nonzero(kasan_mem_to_shadow((void *)addr), - kasan_mem_to_shadow((void *)addr + size - 1) + 1); - - if (unlikely(ret)) { - unsigned long last_byte = addr + size - 1; - s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte); - - if (unlikely(ret != (unsigned long)last_shadow || - ((long)(last_byte & KASAN_SHADOW_MASK) >= *last_shadow))) - return true; - } - return false; -} - -static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size) -{ - if (__builtin_constant_p(size)) { - switch (size) { - case 1: - return memory_is_poisoned_1(addr); - case 2: - case 4: - case 8: - return memory_is_poisoned_2_4_8(addr, size); - case 16: - return memory_is_poisoned_16(addr); - default: - BUILD_BUG(); - } - } - - return memory_is_poisoned_n(addr, size); -} - -static __always_inline void check_memory_region_inline(unsigned long addr, - size_t size, bool write, - unsigned long ret_ip) -{ - if (unlikely(size == 0)) - return; - - if (unlikely((void *)addr < - kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) { - kasan_report(addr, size, write, ret_ip); - return; - } - - if (likely(!memory_is_poisoned(addr, size))) - return; - - kasan_report(addr, size, write, ret_ip); -} - -void check_memory_region(unsigned long addr, size_t size, bool write, - unsigned long ret_ip) -{ - check_memory_region_inline(addr, size, write, ret_ip); -} - -void kasan_cache_shrink(struct kmem_cache *cache) -{ - quarantine_remove_cache(cache); -} - -void kasan_cache_shutdown(struct kmem_cache *cache) -{ - if (!__kmem_cache_empty(cache)) - quarantine_remove_cache(cache); -} - -static void register_global(struct kasan_global *global) -{ - size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE); - - kasan_unpoison_shadow(global->beg, global->size); - - kasan_poison_shadow(global->beg + aligned_size, - global->size_with_redzone - aligned_size, - KASAN_GLOBAL_REDZONE); -} - -void __asan_register_globals(struct kasan_global *globals, size_t size) -{ - int i; - - for (i = 0; i < size; i++) - register_global(&globals[i]); -} -EXPORT_SYMBOL(__asan_register_globals); - -void __asan_unregister_globals(struct kasan_global *globals, size_t size) -{ -} -EXPORT_SYMBOL(__asan_unregister_globals); - -#define DEFINE_ASAN_LOAD_STORE(size) \ - void __asan_load##size(unsigned long addr) \ - { \ - check_memory_region_inline(addr, size, false, _RET_IP_);\ - } \ - EXPORT_SYMBOL(__asan_load##size); \ - __alias(__asan_load##size) \ - void __asan_load##size##_noabort(unsigned long); \ - EXPORT_SYMBOL(__asan_load##size##_noabort); \ - void __asan_store##size(unsigned long addr) \ - { \ - check_memory_region_inline(addr, size, true, _RET_IP_); \ - } \ - EXPORT_SYMBOL(__asan_store##size); \ - __alias(__asan_store##size) \ - void __asan_store##size##_noabort(unsigned long); \ - EXPORT_SYMBOL(__asan_store##size##_noabort) - -DEFINE_ASAN_LOAD_STORE(1); -DEFINE_ASAN_LOAD_STORE(2); -DEFINE_ASAN_LOAD_STORE(4); -DEFINE_ASAN_LOAD_STORE(8); -DEFINE_ASAN_LOAD_STORE(16); - -void __asan_loadN(unsigned long addr, size_t size) -{ - check_memory_region(addr, size, false, _RET_IP_); -} -EXPORT_SYMBOL(__asan_loadN); - -__alias(__asan_loadN) -void __asan_loadN_noabort(unsigned long, size_t); -EXPORT_SYMBOL(__asan_loadN_noabort); - -void __asan_storeN(unsigned long addr, size_t size) -{ - check_memory_region(addr, size, true, _RET_IP_); -} -EXPORT_SYMBOL(__asan_storeN); - -__alias(__asan_storeN) -void __asan_storeN_noabort(unsigned long, size_t); -EXPORT_SYMBOL(__asan_storeN_noabort); - -/* to shut up compiler complaints */ -void __asan_handle_no_return(void) {} -EXPORT_SYMBOL(__asan_handle_no_return); - -/* Emitted by compiler to poison large objects when they go out of scope. */ -void __asan_poison_stack_memory(const void *addr, size_t size) -{ - /* - * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded - * by redzones, so we simply round up size to simplify logic. - */ - kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE), - KASAN_USE_AFTER_SCOPE); -} -EXPORT_SYMBOL(__asan_poison_stack_memory); - -/* Emitted by compiler to unpoison large objects when they go into scope. */ -void __asan_unpoison_stack_memory(const void *addr, size_t size) -{ - kasan_unpoison_shadow(addr, size); -} -EXPORT_SYMBOL(__asan_unpoison_stack_memory); - -/* Emitted by compiler to poison alloca()ed objects. */ -void __asan_alloca_poison(unsigned long addr, size_t size) -{ - size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); - size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) - - rounded_up_size; - size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE); - - const void *left_redzone = (const void *)(addr - - KASAN_ALLOCA_REDZONE_SIZE); - const void *right_redzone = (const void *)(addr + rounded_up_size); - - WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE)); - - kasan_unpoison_shadow((const void *)(addr + rounded_down_size), - size - rounded_down_size); - kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE, - KASAN_ALLOCA_LEFT); - kasan_poison_shadow(right_redzone, - padding_size + KASAN_ALLOCA_REDZONE_SIZE, - KASAN_ALLOCA_RIGHT); -} -EXPORT_SYMBOL(__asan_alloca_poison); - -/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */ -void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) -{ - if (unlikely(!stack_top || stack_top > stack_bottom)) - return; - - kasan_unpoison_shadow(stack_top, stack_bottom - stack_top); -} -EXPORT_SYMBOL(__asan_allocas_unpoison); - -/* Emitted by the compiler to [un]poison local variables. */ -#define DEFINE_ASAN_SET_SHADOW(byte) \ - void __asan_set_shadow_##byte(const void *addr, size_t size) \ - { \ - __memset((void *)addr, 0x##byte, size); \ - } \ - EXPORT_SYMBOL(__asan_set_shadow_##byte) - -DEFINE_ASAN_SET_SHADOW(00); -DEFINE_ASAN_SET_SHADOW(f1); -DEFINE_ASAN_SET_SHADOW(f2); -DEFINE_ASAN_SET_SHADOW(f3); -DEFINE_ASAN_SET_SHADOW(f5); -DEFINE_ASAN_SET_SHADOW(f8); |