Alexey Samsonov | 7e84349 | 2013-03-28 15:42:43 +0000 | [diff] [blame] | 1 | //===-- asan_poisoning.h ----------------------------------------*- C++ -*-===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file is a part of AddressSanitizer, an address sanity checker. |
| 11 | // |
| 12 | // Shadow memory poisoning by ASan RTL and by user application. |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #include "asan_interceptors.h" |
| 16 | #include "asan_internal.h" |
| 17 | #include "asan_mapping.h" |
| 18 | |
| 19 | namespace __asan { |
| 20 | |
| 21 | // Poisons the shadow memory for "size" bytes starting from "addr". |
| 22 | void PoisonShadow(uptr addr, uptr size, u8 value); |
| 23 | |
| 24 | // Poisons the shadow memory for "redzone_size" bytes starting from |
| 25 | // "addr + size". |
| 26 | void PoisonShadowPartialRightRedzone(uptr addr, |
| 27 | uptr size, |
| 28 | uptr redzone_size, |
| 29 | u8 value); |
| 30 | |
| 31 | // Fast versions of PoisonShadow and PoisonShadowPartialRightRedzone that |
| 32 | // assume that memory addresses are properly aligned. Use in |
| 33 | // performance-critical code with care. |
Timur Iskhodzhanov | abfdbdf | 2013-03-28 18:52:40 +0000 | [diff] [blame] | 34 | ALWAYS_INLINE void FastPoisonShadow(uptr aligned_beg, uptr aligned_size, |
Alexey Samsonov | 7e84349 | 2013-03-28 15:42:43 +0000 | [diff] [blame] | 35 | u8 value) { |
| 36 | DCHECK(flags()->poison_heap); |
| 37 | uptr shadow_beg = MEM_TO_SHADOW(aligned_beg); |
| 38 | uptr shadow_end = MEM_TO_SHADOW( |
| 39 | aligned_beg + aligned_size - SHADOW_GRANULARITY) + 1; |
| 40 | REAL(memset)((void*)shadow_beg, value, shadow_end - shadow_beg); |
| 41 | } |
| 42 | |
Timur Iskhodzhanov | abfdbdf | 2013-03-28 18:52:40 +0000 | [diff] [blame] | 43 | ALWAYS_INLINE void FastPoisonShadowPartialRightRedzone( |
Alexey Samsonov | 7e84349 | 2013-03-28 15:42:43 +0000 | [diff] [blame] | 44 | uptr aligned_addr, uptr size, uptr redzone_size, u8 value) { |
| 45 | DCHECK(flags()->poison_heap); |
| 46 | u8 *shadow = (u8*)MEM_TO_SHADOW(aligned_addr); |
| 47 | for (uptr i = 0; i < redzone_size; i += SHADOW_GRANULARITY, shadow++) { |
| 48 | if (i + SHADOW_GRANULARITY <= size) { |
| 49 | *shadow = 0; // fully addressable |
| 50 | } else if (i >= size) { |
| 51 | *shadow = (SHADOW_GRANULARITY == 128) ? 0xff : value; // unaddressable |
| 52 | } else { |
Timur Iskhodzhanov | 5e97ba3 | 2013-05-29 14:11:44 +0000 | [diff] [blame^] | 53 | *shadow = static_cast<u8>(size - i); // first size-i bytes are addressable |
Alexey Samsonov | 7e84349 | 2013-03-28 15:42:43 +0000 | [diff] [blame] | 54 | } |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | } // namespace __asan |