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 // All of the following configurations are supported. 37 // ASLR disabled: main executable and DSOs at 0x555550000000 38 // PIE and ASLR: main executable and DSOs at 0x7f0000000000 39 // non-PIE: main executable below 0x100000000, DSOs at 0x7f0000000000 40 // Heap at 0x700000000000. 41 const MappingDesc kMemoryLayout[] = { 42 {0x000000000000ULL, 0x010000000000ULL, MappingDesc::APP, "app-1"}, 43 {0x010000000000ULL, 0x100000000000ULL, MappingDesc::SHADOW, "shadow-2"}, 44 {0x100000000000ULL, 0x110000000000ULL, MappingDesc::INVALID, "invalid"}, 45 {0x110000000000ULL, 0x200000000000ULL, MappingDesc::ORIGIN, "origin-2"}, 46 {0x200000000000ULL, 0x300000000000ULL, MappingDesc::SHADOW, "shadow-3"}, 47 {0x300000000000ULL, 0x400000000000ULL, MappingDesc::ORIGIN, "origin-3"}, 48 {0x400000000000ULL, 0x500000000000ULL, MappingDesc::INVALID, "invalid"}, 49 {0x500000000000ULL, 0x510000000000ULL, MappingDesc::SHADOW, "shadow-1"}, 50 {0x510000000000ULL, 0x600000000000ULL, MappingDesc::APP, "app-2"}, 51 {0x600000000000ULL, 0x610000000000ULL, MappingDesc::ORIGIN, "origin-1"}, 52 {0x610000000000ULL, 0x700000000000ULL, MappingDesc::INVALID, "invalid"}, 53 {0x700000000000ULL, 0x800000000000ULL, MappingDesc::APP, "app-3"}}; 54 # define MEM_TO_SHADOW(mem) (((uptr)(mem)) ^ 0x500000000000ULL) 55 # define SHADOW_TO_ORIGIN(mem) (((uptr)(mem)) + 0x100000000000ULL) 56 57 #else 58 # error "Unsupported platform" 59 #endif 60 61 const uptr kMemoryLayoutSize = sizeof(kMemoryLayout) / sizeof(kMemoryLayout[0]); 62 63 #define MEM_TO_ORIGIN(mem) (SHADOW_TO_ORIGIN(MEM_TO_SHADOW((mem)))) 64 65 #ifndef __clang__ 66 __attribute__((optimize("unroll-loops"))) 67 #endif 68 inline bool 69 addr_is_type(uptr addr, MappingDesc::Type mapping_type) { 70 // It is critical for performance that this loop is unrolled (because then it is 71 // simplified into just a few constant comparisons). 72 #ifdef __clang__ 73 # pragma unroll 74 #endif 75 for (unsigned i = 0; i < kMemoryLayoutSize; ++i) 76 if (kMemoryLayout[i].type == mapping_type && 77 addr >= kMemoryLayout[i].start && addr < kMemoryLayout[i].end) 78 return true; 79 return false; 80 } 81 82 #define MEM_IS_APP(mem) addr_is_type((uptr)(mem), MappingDesc::APP) 83 #define MEM_IS_SHADOW(mem) addr_is_type((uptr)(mem), MappingDesc::SHADOW) 84 #define MEM_IS_ORIGIN(mem) addr_is_type((uptr)(mem), MappingDesc::ORIGIN) 85 86 } // namespace __dfsan 87 88 #endif 89