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 { INVALID, APP, SHADOW, ORIGIN } type; 31 const char *name; 32 }; 33 34 #if SANITIZER_LINUX && SANITIZER_WORDSIZE == 64 35 36 # if defined(__aarch64__) 37 // The mapping assumes 48-bit VMA. AArch64 maps: 38 // - 0x0000000000000-0x0100000000000: 39/42/48-bits program own segments 39 // - 0x0a00000000000-0x0b00000000000: 48-bits PIE program segments 40 // Ideally, this would extend to 0x0c00000000000 (2^45 bytes - the 41 // maximum ASLR region for 48-bit VMA) but it is too hard to fit in 42 // the larger app/shadow/origin regions. 43 // - 0x0e00000000000-0x1000000000000: 48-bits libraries segments 44 const MappingDesc kMemoryLayout[] = { 45 {0X0000000000000, 0X0100000000000, MappingDesc::APP, "app-10-13"}, 46 {0X0100000000000, 0X0200000000000, MappingDesc::SHADOW, "shadow-14"}, 47 {0X0200000000000, 0X0300000000000, MappingDesc::INVALID, "invalid"}, 48 {0X0300000000000, 0X0400000000000, MappingDesc::ORIGIN, "origin-14"}, 49 {0X0400000000000, 0X0600000000000, MappingDesc::SHADOW, "shadow-15"}, 50 {0X0600000000000, 0X0800000000000, MappingDesc::ORIGIN, "origin-15"}, 51 {0X0800000000000, 0X0A00000000000, MappingDesc::INVALID, "invalid"}, 52 {0X0A00000000000, 0X0B00000000000, MappingDesc::APP, "app-14"}, 53 {0X0B00000000000, 0X0C00000000000, MappingDesc::SHADOW, "shadow-10-13"}, 54 {0X0C00000000000, 0X0D00000000000, MappingDesc::INVALID, "invalid"}, 55 {0X0D00000000000, 0X0E00000000000, MappingDesc::ORIGIN, "origin-10-13"}, 56 {0X0E00000000000, 0X1000000000000, MappingDesc::APP, "app-15"}, 57 }; 58 # define MEM_TO_SHADOW(mem) ((uptr)mem ^ 0xB00000000000ULL) 59 # define SHADOW_TO_ORIGIN(shadow) (((uptr)(shadow)) + 0x200000000000ULL) 60 61 # else 62 // All of the following configurations are supported. 63 // ASLR disabled: main executable and DSOs at 0x555550000000 64 // PIE and ASLR: main executable and DSOs at 0x7f0000000000 65 // non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000 66 // Heap at 0x700000000000. 67 const MappingDesc kMemoryLayout[] = { 68 {0x000000000000ULL, 0x010000000000ULL, MappingDesc::APP, "app-1"}, 69 {0x010000000000ULL, 0x100000000000ULL, MappingDesc::SHADOW, "shadow-2"}, 70 {0x100000000000ULL, 0x110000000000ULL, MappingDesc::INVALID, "invalid"}, 71 {0x110000000000ULL, 0x200000000000ULL, MappingDesc::ORIGIN, "origin-2"}, 72 {0x200000000000ULL, 0x300000000000ULL, MappingDesc::SHADOW, "shadow-3"}, 73 {0x300000000000ULL, 0x400000000000ULL, MappingDesc::ORIGIN, "origin-3"}, 74 {0x400000000000ULL, 0x500000000000ULL, MappingDesc::INVALID, "invalid"}, 75 {0x500000000000ULL, 0x510000000000ULL, MappingDesc::SHADOW, "shadow-1"}, 76 {0x510000000000ULL, 0x600000000000ULL, MappingDesc::APP, "app-2"}, 77 {0x600000000000ULL, 0x610000000000ULL, MappingDesc::ORIGIN, "origin-1"}, 78 {0x610000000000ULL, 0x700000000000ULL, MappingDesc::INVALID, "invalid"}, 79 {0x700000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app-3"}}; 80 # define MEM_TO_SHADOW(mem) (((uptr)(mem)) ^ 0x500000000000ULL) 81 # define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x100000000000ULL) 82 # endif 83 84 #else 85 # error "Unsupported platform" 86 #endif 87 88 const uptr kMemoryLayoutSize = sizeof(kMemoryLayout) / sizeof(kMemoryLayout[0]); 89 90 #define MEM_TO_ORIGIN(mem) (SHADOW_TO_ORIGIN(MEM_TO_SHADOW((mem)))) 91 92 #ifndef __clang__ 93 __attribute__((optimize("unroll-loops"))) 94 #endif 95 inline bool 96 addr_is_type(uptr addr, MappingDesc::Type mapping_type) { 97 // It is critical for performance that this loop is unrolled (because then it is 98 // simplified into just a few constant comparisons). 99 #ifdef __clang__ 100 # pragma unroll 101 #endif 102 for (unsigned i = 0; i < kMemoryLayoutSize; ++i) 103 if (kMemoryLayout[i].type == mapping_type && 104 addr >= kMemoryLayout[i].start && addr < kMemoryLayout[i].end) 105 return true; 106 return false; 107 } 108 109 #define MEM_IS_APP(mem) addr_is_type((uptr)(mem), MappingDesc::APP) 110 #define MEM_IS_SHADOW(mem) addr_is_type((uptr)(mem), MappingDesc::SHADOW) 111 #define MEM_IS_ORIGIN(mem) addr_is_type((uptr)(mem), MappingDesc::ORIGIN) 112 113 } // namespace __dfsan 114 115 #endif 116