1 //===-- tsan_platform_posix.cpp -------------------------------------------===// 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 ThreadSanitizer (TSan), a race detector. 10 // 11 // POSIX-specific code. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_common/sanitizer_platform.h" 15 #if SANITIZER_POSIX 16 17 # include <dlfcn.h> 18 19 # include "sanitizer_common/sanitizer_common.h" 20 # include "sanitizer_common/sanitizer_errno.h" 21 # include "sanitizer_common/sanitizer_libc.h" 22 # include "sanitizer_common/sanitizer_procmaps.h" 23 # include "tsan_platform.h" 24 # include "tsan_rtl.h" 25 26 namespace __tsan { 27 28 static const char kShadowMemoryMappingWarning[] = 29 "FATAL: %s can not madvise shadow region [%zx, %zx] with %s (errno: %d)\n"; 30 static const char kShadowMemoryMappingHint[] = 31 "HINT: if %s is not supported in your environment, you may set " 32 "TSAN_OPTIONS=%s=0\n"; 33 34 # if !SANITIZER_GO 35 void DontDumpShadow(uptr addr, uptr size) { 36 if (common_flags()->use_madv_dontdump) 37 if (!DontDumpShadowMemory(addr, size)) { 38 Printf(kShadowMemoryMappingWarning, SanitizerToolName, addr, addr + size, 39 "MADV_DONTDUMP", errno); 40 Printf(kShadowMemoryMappingHint, "MADV_DONTDUMP", "use_madv_dontdump"); 41 Die(); 42 } 43 } 44 45 void InitializeShadowMemory() { 46 // Map memory shadow. 47 if (!MmapFixedSuperNoReserve(ShadowBeg(), ShadowEnd() - ShadowBeg(), 48 "shadow")) { 49 Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n"); 50 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n"); 51 Die(); 52 } 53 // This memory range is used for thread stacks and large user mmaps. 54 // Frequently a thread uses only a small part of stack and similarly 55 // a program uses a small part of large mmap. On some programs 56 // we see 20% memory usage reduction without huge pages for this range. 57 DontDumpShadow(ShadowBeg(), ShadowEnd() - ShadowBeg()); 58 DPrintf("memory shadow: %zx-%zx (%zuGB)\n", 59 ShadowBeg(), ShadowEnd(), 60 (ShadowEnd() - ShadowBeg()) >> 30); 61 62 // Map meta shadow. 63 const uptr meta = MetaShadowBeg(); 64 const uptr meta_size = MetaShadowEnd() - meta; 65 if (!MmapFixedSuperNoReserve(meta, meta_size, "meta shadow")) { 66 Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n"); 67 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n"); 68 Die(); 69 } 70 DontDumpShadow(meta, meta_size); 71 DPrintf("meta shadow: %zx-%zx (%zuGB)\n", 72 meta, meta + meta_size, meta_size >> 30); 73 74 InitializeShadowMemoryPlatform(); 75 76 on_initialize = reinterpret_cast<void (*)(void)>( 77 dlsym(RTLD_DEFAULT, "__tsan_on_initialize")); 78 on_finalize = 79 reinterpret_cast<int (*)(int)>(dlsym(RTLD_DEFAULT, "__tsan_on_finalize")); 80 } 81 82 static bool TryProtectRange(uptr beg, uptr end) { 83 CHECK_LE(beg, end); 84 if (beg == end) 85 return true; 86 return beg == (uptr)MmapFixedNoAccess(beg, end - beg); 87 } 88 89 static void ProtectRange(uptr beg, uptr end) { 90 if (!TryProtectRange(beg, end)) { 91 Printf("FATAL: ThreadSanitizer can not protect [%zx,%zx]\n", beg, end); 92 Printf("FATAL: Make sure you are not using unlimited stack\n"); 93 Die(); 94 } 95 } 96 97 void CheckAndProtect() { 98 // Ensure that the binary is indeed compiled with -pie. 99 MemoryMappingLayout proc_maps(true); 100 MemoryMappedSegment segment; 101 while (proc_maps.Next(&segment)) { 102 if (IsAppMem(segment.start)) continue; 103 if (segment.start >= HeapMemEnd() && segment.start < HeapEnd()) continue; 104 if (segment.protection == 0) // Zero page or mprotected. 105 continue; 106 if (segment.start >= VdsoBeg()) // vdso 107 break; 108 Printf("FATAL: ThreadSanitizer: unexpected memory mapping 0x%zx-0x%zx\n", 109 segment.start, segment.end); 110 Die(); 111 } 112 113 # if SANITIZER_IOS && !SANITIZER_IOSSIM 114 ProtectRange(HeapMemEnd(), ShadowBeg()); 115 ProtectRange(ShadowEnd(), MetaShadowBeg()); 116 ProtectRange(MetaShadowEnd(), HiAppMemBeg()); 117 # else 118 ProtectRange(LoAppMemEnd(), ShadowBeg()); 119 ProtectRange(ShadowEnd(), MetaShadowBeg()); 120 if (MidAppMemBeg()) { 121 ProtectRange(MetaShadowEnd(), MidAppMemBeg()); 122 ProtectRange(MidAppMemEnd(), HeapMemBeg()); 123 } else { 124 ProtectRange(MetaShadowEnd(), HeapMemBeg()); 125 } 126 ProtectRange(HeapEnd(), HiAppMemBeg()); 127 # endif 128 129 # if defined(__s390x__) 130 // Protect the rest of the address space. 131 const uptr user_addr_max_l4 = 0x0020000000000000ull; 132 const uptr user_addr_max_l5 = 0xfffffffffffff000ull; 133 // All the maintained s390x kernels support at least 4-level page tables. 134 ProtectRange(HiAppMemEnd(), user_addr_max_l4); 135 // Older s390x kernels may not support 5-level page tables. 136 TryProtectRange(user_addr_max_l4, user_addr_max_l5); 137 #endif 138 } 139 #endif 140 141 } // namespace __tsan 142 143 #endif // SANITIZER_POSIX 144