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https://github.com/edk2-porting/linux-next.git
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25add7ec70
We decided to use KASAN as the short name of the tool and KernelAddressSanitizer as the full one. Update log messages according to that. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
531 lines
12 KiB
C
531 lines
12 KiB
C
/*
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* This file contains shadow memory manipulation code.
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*
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* Copyright (c) 2014 Samsung Electronics Co., Ltd.
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* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
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*
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* Some of code borrowed from https://github.com/xairy/linux by
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* Andrey Konovalov <adech.fo@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#define DISABLE_BRANCH_PROFILING
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#include <linux/export.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/memblock.h>
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#include <linux/memory.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/printk.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/stacktrace.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/vmalloc.h>
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#include <linux/kasan.h>
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#include "kasan.h"
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#include "../slab.h"
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/*
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* Poisons the shadow memory for 'size' bytes starting from 'addr'.
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* Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE.
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*/
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static void kasan_poison_shadow(const void *address, size_t size, u8 value)
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{
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void *shadow_start, *shadow_end;
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shadow_start = kasan_mem_to_shadow(address);
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shadow_end = kasan_mem_to_shadow(address + size);
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memset(shadow_start, value, shadow_end - shadow_start);
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}
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void kasan_unpoison_shadow(const void *address, size_t size)
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{
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kasan_poison_shadow(address, size, 0);
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if (size & KASAN_SHADOW_MASK) {
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u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size);
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*shadow = size & KASAN_SHADOW_MASK;
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}
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}
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/*
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* All functions below always inlined so compiler could
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* perform better optimizations in each of __asan_loadX/__assn_storeX
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* depending on memory access size X.
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*/
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static __always_inline bool memory_is_poisoned_1(unsigned long addr)
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{
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s8 shadow_value = *(s8 *)kasan_mem_to_shadow((void *)addr);
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if (unlikely(shadow_value)) {
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s8 last_accessible_byte = addr & KASAN_SHADOW_MASK;
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return unlikely(last_accessible_byte >= shadow_value);
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}
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return false;
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}
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static __always_inline bool memory_is_poisoned_2(unsigned long addr)
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{
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u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
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if (unlikely(*shadow_addr)) {
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if (memory_is_poisoned_1(addr + 1))
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return true;
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if (likely(((addr + 1) & KASAN_SHADOW_MASK) != 0))
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return false;
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return unlikely(*(u8 *)shadow_addr);
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}
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return false;
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}
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static __always_inline bool memory_is_poisoned_4(unsigned long addr)
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{
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u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
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if (unlikely(*shadow_addr)) {
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if (memory_is_poisoned_1(addr + 3))
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return true;
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if (likely(((addr + 3) & KASAN_SHADOW_MASK) >= 3))
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return false;
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return unlikely(*(u8 *)shadow_addr);
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}
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return false;
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}
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static __always_inline bool memory_is_poisoned_8(unsigned long addr)
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{
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u16 *shadow_addr = (u16 *)kasan_mem_to_shadow((void *)addr);
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if (unlikely(*shadow_addr)) {
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if (memory_is_poisoned_1(addr + 7))
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return true;
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if (likely(((addr + 7) & KASAN_SHADOW_MASK) >= 7))
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return false;
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return unlikely(*(u8 *)shadow_addr);
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}
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return false;
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}
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static __always_inline bool memory_is_poisoned_16(unsigned long addr)
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{
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u32 *shadow_addr = (u32 *)kasan_mem_to_shadow((void *)addr);
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if (unlikely(*shadow_addr)) {
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u16 shadow_first_bytes = *(u16 *)shadow_addr;
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if (unlikely(shadow_first_bytes))
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return true;
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if (likely(IS_ALIGNED(addr, 8)))
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return false;
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return memory_is_poisoned_1(addr + 15);
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}
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return false;
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}
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static __always_inline unsigned long bytes_is_zero(const u8 *start,
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size_t size)
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{
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while (size) {
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if (unlikely(*start))
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return (unsigned long)start;
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start++;
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size--;
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}
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return 0;
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}
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static __always_inline unsigned long memory_is_zero(const void *start,
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const void *end)
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{
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unsigned int words;
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unsigned long ret;
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unsigned int prefix = (unsigned long)start % 8;
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if (end - start <= 16)
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return bytes_is_zero(start, end - start);
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if (prefix) {
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prefix = 8 - prefix;
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ret = bytes_is_zero(start, prefix);
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if (unlikely(ret))
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return ret;
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start += prefix;
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}
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words = (end - start) / 8;
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while (words) {
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if (unlikely(*(u64 *)start))
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return bytes_is_zero(start, 8);
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start += 8;
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words--;
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}
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return bytes_is_zero(start, (end - start) % 8);
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}
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static __always_inline bool memory_is_poisoned_n(unsigned long addr,
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size_t size)
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{
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unsigned long ret;
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ret = memory_is_zero(kasan_mem_to_shadow((void *)addr),
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kasan_mem_to_shadow((void *)addr + size - 1) + 1);
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if (unlikely(ret)) {
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unsigned long last_byte = addr + size - 1;
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s8 *last_shadow = (s8 *)kasan_mem_to_shadow((void *)last_byte);
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if (unlikely(ret != (unsigned long)last_shadow ||
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((last_byte & KASAN_SHADOW_MASK) >= *last_shadow)))
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return true;
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}
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return false;
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}
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static __always_inline bool memory_is_poisoned(unsigned long addr, size_t size)
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{
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if (__builtin_constant_p(size)) {
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switch (size) {
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case 1:
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return memory_is_poisoned_1(addr);
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case 2:
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return memory_is_poisoned_2(addr);
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case 4:
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return memory_is_poisoned_4(addr);
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case 8:
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return memory_is_poisoned_8(addr);
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case 16:
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return memory_is_poisoned_16(addr);
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default:
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BUILD_BUG();
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}
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}
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return memory_is_poisoned_n(addr, size);
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}
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static __always_inline void check_memory_region(unsigned long addr,
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size_t size, bool write)
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{
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if (unlikely(size == 0))
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return;
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if (unlikely((void *)addr <
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kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
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kasan_report(addr, size, write, _RET_IP_);
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return;
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}
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if (likely(!memory_is_poisoned(addr, size)))
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return;
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kasan_report(addr, size, write, _RET_IP_);
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}
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void __asan_loadN(unsigned long addr, size_t size);
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void __asan_storeN(unsigned long addr, size_t size);
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#undef memset
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void *memset(void *addr, int c, size_t len)
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{
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__asan_storeN((unsigned long)addr, len);
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return __memset(addr, c, len);
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}
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#undef memmove
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void *memmove(void *dest, const void *src, size_t len)
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{
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__asan_loadN((unsigned long)src, len);
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__asan_storeN((unsigned long)dest, len);
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return __memmove(dest, src, len);
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}
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#undef memcpy
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void *memcpy(void *dest, const void *src, size_t len)
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{
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__asan_loadN((unsigned long)src, len);
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__asan_storeN((unsigned long)dest, len);
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return __memcpy(dest, src, len);
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}
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void kasan_alloc_pages(struct page *page, unsigned int order)
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{
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if (likely(!PageHighMem(page)))
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kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order);
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}
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void kasan_free_pages(struct page *page, unsigned int order)
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{
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if (likely(!PageHighMem(page)))
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kasan_poison_shadow(page_address(page),
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PAGE_SIZE << order,
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KASAN_FREE_PAGE);
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}
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void kasan_poison_slab(struct page *page)
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{
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kasan_poison_shadow(page_address(page),
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PAGE_SIZE << compound_order(page),
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KASAN_KMALLOC_REDZONE);
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}
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void kasan_unpoison_object_data(struct kmem_cache *cache, void *object)
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{
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kasan_unpoison_shadow(object, cache->object_size);
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}
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void kasan_poison_object_data(struct kmem_cache *cache, void *object)
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{
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kasan_poison_shadow(object,
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round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE),
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KASAN_KMALLOC_REDZONE);
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}
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void kasan_slab_alloc(struct kmem_cache *cache, void *object)
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{
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kasan_kmalloc(cache, object, cache->object_size);
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}
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void kasan_slab_free(struct kmem_cache *cache, void *object)
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{
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unsigned long size = cache->object_size;
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unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
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/* RCU slabs could be legally used after free within the RCU period */
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if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU))
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return;
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kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE);
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}
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void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size)
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{
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unsigned long redzone_start;
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unsigned long redzone_end;
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if (unlikely(object == NULL))
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return;
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redzone_start = round_up((unsigned long)(object + size),
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KASAN_SHADOW_SCALE_SIZE);
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redzone_end = round_up((unsigned long)object + cache->object_size,
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KASAN_SHADOW_SCALE_SIZE);
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kasan_unpoison_shadow(object, size);
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kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
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KASAN_KMALLOC_REDZONE);
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}
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EXPORT_SYMBOL(kasan_kmalloc);
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void kasan_kmalloc_large(const void *ptr, size_t size)
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{
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struct page *page;
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unsigned long redzone_start;
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unsigned long redzone_end;
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if (unlikely(ptr == NULL))
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return;
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page = virt_to_page(ptr);
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redzone_start = round_up((unsigned long)(ptr + size),
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KASAN_SHADOW_SCALE_SIZE);
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redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page));
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kasan_unpoison_shadow(ptr, size);
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kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start,
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KASAN_PAGE_REDZONE);
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}
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void kasan_krealloc(const void *object, size_t size)
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{
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struct page *page;
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if (unlikely(object == ZERO_SIZE_PTR))
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return;
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page = virt_to_head_page(object);
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if (unlikely(!PageSlab(page)))
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kasan_kmalloc_large(object, size);
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else
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kasan_kmalloc(page->slab_cache, object, size);
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}
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void kasan_kfree(void *ptr)
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{
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struct page *page;
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page = virt_to_head_page(ptr);
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if (unlikely(!PageSlab(page)))
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kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
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KASAN_FREE_PAGE);
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else
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kasan_slab_free(page->slab_cache, ptr);
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}
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void kasan_kfree_large(const void *ptr)
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{
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struct page *page = virt_to_page(ptr);
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kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page),
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KASAN_FREE_PAGE);
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}
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int kasan_module_alloc(void *addr, size_t size)
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{
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void *ret;
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size_t shadow_size;
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unsigned long shadow_start;
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shadow_start = (unsigned long)kasan_mem_to_shadow(addr);
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shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT,
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PAGE_SIZE);
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if (WARN_ON(!PAGE_ALIGNED(shadow_start)))
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return -EINVAL;
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ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
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shadow_start + shadow_size,
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GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
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PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
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__builtin_return_address(0));
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if (ret) {
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find_vm_area(addr)->flags |= VM_KASAN;
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return 0;
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}
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return -ENOMEM;
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}
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void kasan_free_shadow(const struct vm_struct *vm)
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{
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if (vm->flags & VM_KASAN)
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vfree(kasan_mem_to_shadow(vm->addr));
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}
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static void register_global(struct kasan_global *global)
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{
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size_t aligned_size = round_up(global->size, KASAN_SHADOW_SCALE_SIZE);
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kasan_unpoison_shadow(global->beg, global->size);
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kasan_poison_shadow(global->beg + aligned_size,
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global->size_with_redzone - aligned_size,
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KASAN_GLOBAL_REDZONE);
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}
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void __asan_register_globals(struct kasan_global *globals, size_t size)
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{
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int i;
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for (i = 0; i < size; i++)
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register_global(&globals[i]);
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}
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EXPORT_SYMBOL(__asan_register_globals);
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void __asan_unregister_globals(struct kasan_global *globals, size_t size)
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{
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}
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EXPORT_SYMBOL(__asan_unregister_globals);
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#define DEFINE_ASAN_LOAD_STORE(size) \
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void __asan_load##size(unsigned long addr) \
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{ \
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check_memory_region(addr, size, false); \
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} \
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EXPORT_SYMBOL(__asan_load##size); \
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__alias(__asan_load##size) \
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void __asan_load##size##_noabort(unsigned long); \
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EXPORT_SYMBOL(__asan_load##size##_noabort); \
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void __asan_store##size(unsigned long addr) \
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{ \
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check_memory_region(addr, size, true); \
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} \
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EXPORT_SYMBOL(__asan_store##size); \
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__alias(__asan_store##size) \
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void __asan_store##size##_noabort(unsigned long); \
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EXPORT_SYMBOL(__asan_store##size##_noabort)
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DEFINE_ASAN_LOAD_STORE(1);
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DEFINE_ASAN_LOAD_STORE(2);
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DEFINE_ASAN_LOAD_STORE(4);
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DEFINE_ASAN_LOAD_STORE(8);
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DEFINE_ASAN_LOAD_STORE(16);
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void __asan_loadN(unsigned long addr, size_t size)
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{
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check_memory_region(addr, size, false);
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}
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EXPORT_SYMBOL(__asan_loadN);
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__alias(__asan_loadN)
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void __asan_loadN_noabort(unsigned long, size_t);
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EXPORT_SYMBOL(__asan_loadN_noabort);
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void __asan_storeN(unsigned long addr, size_t size)
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{
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check_memory_region(addr, size, true);
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}
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EXPORT_SYMBOL(__asan_storeN);
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__alias(__asan_storeN)
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void __asan_storeN_noabort(unsigned long, size_t);
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EXPORT_SYMBOL(__asan_storeN_noabort);
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/* to shut up compiler complaints */
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void __asan_handle_no_return(void) {}
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EXPORT_SYMBOL(__asan_handle_no_return);
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#ifdef CONFIG_MEMORY_HOTPLUG
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static int kasan_mem_notifier(struct notifier_block *nb,
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unsigned long action, void *data)
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{
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return (action == MEM_GOING_ONLINE) ? NOTIFY_BAD : NOTIFY_OK;
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}
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static int __init kasan_memhotplug_init(void)
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{
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pr_err("WARNING: KASAN doesn't support memory hot-add\n");
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pr_err("Memory hot-add will be disabled\n");
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hotplug_memory_notifier(kasan_mem_notifier, 0);
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return 0;
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}
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module_init(kasan_memhotplug_init);
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#endif
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