forked from OSchip/llvm-project
101 lines
3.9 KiB
C++
101 lines
3.9 KiB
C++
//===-- asan_poisoning.h ----------------------------------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file is a part of AddressSanitizer, an address sanity checker.
|
|
//
|
|
// Shadow memory poisoning by ASan RTL and by user application.
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "asan_interceptors.h"
|
|
#include "asan_internal.h"
|
|
#include "asan_mapping.h"
|
|
#include "sanitizer_common/sanitizer_flags.h"
|
|
#include "sanitizer_common/sanitizer_platform.h"
|
|
|
|
namespace __asan {
|
|
|
|
// Enable/disable memory poisoning.
|
|
void SetCanPoisonMemory(bool value);
|
|
bool CanPoisonMemory();
|
|
|
|
// Poisons the shadow memory for "size" bytes starting from "addr".
|
|
void PoisonShadow(uptr addr, uptr size, u8 value);
|
|
|
|
// Poisons the shadow memory for "redzone_size" bytes starting from
|
|
// "addr + size".
|
|
void PoisonShadowPartialRightRedzone(uptr addr,
|
|
uptr size,
|
|
uptr redzone_size,
|
|
u8 value);
|
|
|
|
// Fast versions of PoisonShadow and PoisonShadowPartialRightRedzone that
|
|
// assume that memory addresses are properly aligned. Use in
|
|
// performance-critical code with care.
|
|
ALWAYS_INLINE void FastPoisonShadow(uptr aligned_beg, uptr aligned_size,
|
|
u8 value) {
|
|
DCHECK(!value || CanPoisonMemory());
|
|
#if SANITIZER_FUCHSIA
|
|
__sanitizer_fill_shadow(aligned_beg, aligned_size, value,
|
|
common_flags()->clear_shadow_mmap_threshold);
|
|
#else
|
|
uptr shadow_beg = MEM_TO_SHADOW(aligned_beg);
|
|
uptr shadow_end = MEM_TO_SHADOW(
|
|
aligned_beg + aligned_size - SHADOW_GRANULARITY) + 1;
|
|
// FIXME: Page states are different on Windows, so using the same interface
|
|
// for mapping shadow and zeroing out pages doesn't "just work", so we should
|
|
// probably provide higher-level interface for these operations.
|
|
// For now, just memset on Windows.
|
|
if (value || SANITIZER_WINDOWS == 1 ||
|
|
// RTEMS doesn't have have pages, let alone a fast way to zero
|
|
// them, so default to memset.
|
|
SANITIZER_RTEMS == 1 ||
|
|
shadow_end - shadow_beg < common_flags()->clear_shadow_mmap_threshold) {
|
|
REAL(memset)((void*)shadow_beg, value, shadow_end - shadow_beg);
|
|
} else {
|
|
uptr page_size = GetPageSizeCached();
|
|
uptr page_beg = RoundUpTo(shadow_beg, page_size);
|
|
uptr page_end = RoundDownTo(shadow_end, page_size);
|
|
|
|
if (page_beg >= page_end) {
|
|
REAL(memset)((void *)shadow_beg, 0, shadow_end - shadow_beg);
|
|
} else {
|
|
if (page_beg != shadow_beg) {
|
|
REAL(memset)((void *)shadow_beg, 0, page_beg - shadow_beg);
|
|
}
|
|
if (page_end != shadow_end) {
|
|
REAL(memset)((void *)page_end, 0, shadow_end - page_end);
|
|
}
|
|
ReserveShadowMemoryRange(page_beg, page_end - 1, nullptr);
|
|
}
|
|
}
|
|
#endif // SANITIZER_FUCHSIA
|
|
}
|
|
|
|
ALWAYS_INLINE void FastPoisonShadowPartialRightRedzone(
|
|
uptr aligned_addr, uptr size, uptr redzone_size, u8 value) {
|
|
DCHECK(CanPoisonMemory());
|
|
bool poison_partial = flags()->poison_partial;
|
|
u8 *shadow = (u8*)MEM_TO_SHADOW(aligned_addr);
|
|
for (uptr i = 0; i < redzone_size; i += SHADOW_GRANULARITY, shadow++) {
|
|
if (i + SHADOW_GRANULARITY <= size) {
|
|
*shadow = 0; // fully addressable
|
|
} else if (i >= size) {
|
|
*shadow = (SHADOW_GRANULARITY == 128) ? 0xff : value; // unaddressable
|
|
} else {
|
|
// first size-i bytes are addressable
|
|
*shadow = poison_partial ? static_cast<u8>(size - i) : 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Calls __sanitizer::ReleaseMemoryPagesToOS() on
|
|
// [MemToShadow(p), MemToShadow(p+size)].
|
|
void FlushUnneededASanShadowMemory(uptr p, uptr size);
|
|
|
|
} // namespace __asan
|