1 //===-- dfsan_platform.h ----------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of DataFlowSanitizer. 10 // 11 // Platform specific information for DFSan. 12 //===----------------------------------------------------------------------===// 13 14 #ifndef DFSAN_PLATFORM_H 15 #define DFSAN_PLATFORM_H 16 17 #include "sanitizer_common/sanitizer_common.h" 18 #include "sanitizer_common/sanitizer_platform.h" 19 20 namespace __dfsan { 21 22 using __sanitizer::uptr; 23 24 // TODO: The memory mapping code to setup a 1:1 shadow is based on msan. 25 // Consider refactoring these into a shared implementation. 26 27 struct MappingDesc { 28 uptr start; 29 uptr end; 30 enum Type { 31 INVALID = 1, 32 ALLOCATOR = 2, 33 APP = 4, 34 SHADOW = 8, 35 ORIGIN = 16, 36 } type; 37 const char *name; 38 }; 39 40 // Note: MappingDesc::ALLOCATOR entries are only used to check for memory 41 // layout compatibility. The actual allocation settings are in 42 // dfsan_allocator.cpp, which need to be kept in sync. 43 #if SANITIZER_LINUX && SANITIZER_WORDSIZE == 64 44 45 # if defined(__aarch64__) 46 // The mapping assumes 48-bit VMA. AArch64 maps: 47 // - 0x0000000000000-0x0100000000000: 39/42/48-bits program own segments 48 // - 0x0a00000000000-0x0b00000000000: 48-bits PIE program segments 49 // Ideally, this would extend to 0x0c00000000000 (2^45 bytes - the 50 // maximum ASLR region for 48-bit VMA) but it is too hard to fit in 51 // the larger app/shadow/origin regions. 52 // - 0x0e00000000000-0x1000000000000: 48-bits libraries segments 53 const MappingDesc kMemoryLayout[] = { 54 {0X0000000000000, 0X0100000000000, MappingDesc::APP, "app-10-13"}, 55 {0X0100000000000, 0X0200000000000, MappingDesc::SHADOW, "shadow-14"}, 56 {0X0200000000000, 0X0300000000000, MappingDesc::INVALID, "invalid"}, 57 {0X0300000000000, 0X0400000000000, MappingDesc::ORIGIN, "origin-14"}, 58 {0X0400000000000, 0X0600000000000, MappingDesc::SHADOW, "shadow-15"}, 59 {0X0600000000000, 0X0800000000000, MappingDesc::ORIGIN, "origin-15"}, 60 {0X0800000000000, 0X0A00000000000, MappingDesc::INVALID, "invalid"}, 61 {0X0A00000000000, 0X0B00000000000, MappingDesc::APP, "app-14"}, 62 {0X0B00000000000, 0X0C00000000000, MappingDesc::SHADOW, "shadow-10-13"}, 63 {0X0C00000000000, 0X0D00000000000, MappingDesc::INVALID, "invalid"}, 64 {0X0D00000000000, 0X0E00000000000, MappingDesc::ORIGIN, "origin-10-13"}, 65 {0X0E00000000000, 0X0E40000000000, MappingDesc::ALLOCATOR, "allocator"}, 66 {0X0E40000000000, 0X1000000000000, MappingDesc::APP, "app-15"}, 67 }; 68 # define MEM_TO_SHADOW(mem) ((uptr)mem ^ 0xB00000000000ULL) 69 # define SHADOW_TO_ORIGIN(shadow) (((uptr)(shadow)) + 0x200000000000ULL) 70 71 # else 72 // All of the following configurations are supported. 73 // ASLR disabled: main executable and DSOs at 0x555550000000 74 // PIE and ASLR: main executable and DSOs at 0x7f0000000000 75 // non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000 76 // Heap at 0x700000000000. 77 const MappingDesc kMemoryLayout[] = { 78 {0x000000000000ULL, 0x010000000000ULL, MappingDesc::APP, "app-1"}, 79 {0x010000000000ULL, 0x100000000000ULL, MappingDesc::SHADOW, "shadow-2"}, 80 {0x100000000000ULL, 0x110000000000ULL, MappingDesc::INVALID, "invalid"}, 81 {0x110000000000ULL, 0x200000000000ULL, MappingDesc::ORIGIN, "origin-2"}, 82 {0x200000000000ULL, 0x300000000000ULL, MappingDesc::SHADOW, "shadow-3"}, 83 {0x300000000000ULL, 0x400000000000ULL, MappingDesc::ORIGIN, "origin-3"}, 84 {0x400000000000ULL, 0x500000000000ULL, MappingDesc::INVALID, "invalid"}, 85 {0x500000000000ULL, 0x510000000000ULL, MappingDesc::SHADOW, "shadow-1"}, 86 {0x510000000000ULL, 0x600000000000ULL, MappingDesc::APP, "app-2"}, 87 {0x600000000000ULL, 0x610000000000ULL, MappingDesc::ORIGIN, "origin-1"}, 88 {0x610000000000ULL, 0x700000000000ULL, MappingDesc::INVALID, "invalid"}, 89 {0x700000000000ULL, 0x740000000000ULL, MappingDesc::ALLOCATOR, "allocator"}, 90 {0x740000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app-3"}}; 91 # define MEM_TO_SHADOW(mem) (((uptr)(mem)) ^ 0x500000000000ULL) 92 # define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x100000000000ULL) 93 # endif 94 95 #else 96 # error "Unsupported platform" 97 #endif 98 99 const uptr kMemoryLayoutSize = sizeof(kMemoryLayout) / sizeof(kMemoryLayout[0]); 100 101 #define MEM_TO_ORIGIN(mem) (SHADOW_TO_ORIGIN(MEM_TO_SHADOW((mem)))) 102 103 #ifndef __clang__ 104 __attribute__((optimize("unroll-loops"))) 105 #endif 106 inline bool 107 addr_is_type(uptr addr, int mapping_types) { 108 // It is critical for performance that this loop is unrolled (because then it is 109 // simplified into just a few constant comparisons). 110 #ifdef __clang__ 111 # pragma unroll 112 #endif 113 for (unsigned i = 0; i < kMemoryLayoutSize; ++i) 114 if ((kMemoryLayout[i].type & mapping_types) && 115 addr >= kMemoryLayout[i].start && addr < kMemoryLayout[i].end) 116 return true; 117 return false; 118 } 119 120 #define MEM_IS_APP(mem) \ 121 (addr_is_type((uptr)(mem), MappingDesc::APP | MappingDesc::ALLOCATOR)) 122 #define MEM_IS_SHADOW(mem) addr_is_type((uptr)(mem), MappingDesc::SHADOW) 123 #define MEM_IS_ORIGIN(mem) addr_is_type((uptr)(mem), MappingDesc::ORIGIN) 124 125 } // namespace __dfsan 126 127 #endif 128