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 "sanitizer_common/sanitizer_common.h" 18 #include "sanitizer_common/sanitizer_errno.h" 19 #include "sanitizer_common/sanitizer_libc.h" 20 #include "sanitizer_common/sanitizer_procmaps.h" 21 #include "tsan_platform.h" 22 #include "tsan_rtl.h" 23 24 namespace __tsan { 25 26 static const char kShadowMemoryMappingWarning[] = 27 "FATAL: %s can not madvise shadow region [%zx, %zx] with %s (errno: %d)\n"; 28 static const char kShadowMemoryMappingHint[] = 29 "HINT: if %s is not supported in your environment, you may set " 30 "TSAN_OPTIONS=%s=0\n"; 31 32 static void DontDumpShadow(uptr addr, uptr size) { 33 if (common_flags()->use_madv_dontdump) 34 if (!DontDumpShadowMemory(addr, size)) { 35 Printf(kShadowMemoryMappingWarning, SanitizerToolName, addr, addr + size, 36 "MADV_DONTDUMP", errno); 37 Printf(kShadowMemoryMappingHint, "MADV_DONTDUMP", "use_madv_dontdump"); 38 Die(); 39 } 40 } 41 42 #if !SANITIZER_GO 43 void InitializeShadowMemory() { 44 // Map memory shadow. 45 if (!MmapFixedSuperNoReserve(ShadowBeg(), ShadowEnd() - ShadowBeg(), 46 "shadow")) { 47 Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n"); 48 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n"); 49 Die(); 50 } 51 // This memory range is used for thread stacks and large user mmaps. 52 // Frequently a thread uses only a small part of stack and similarly 53 // a program uses a small part of large mmap. On some programs 54 // we see 20% memory usage reduction without huge pages for this range. 55 DontDumpShadow(ShadowBeg(), ShadowEnd() - ShadowBeg()); 56 DPrintf("memory shadow: %zx-%zx (%zuGB)\n", 57 ShadowBeg(), ShadowEnd(), 58 (ShadowEnd() - ShadowBeg()) >> 30); 59 60 // Map meta shadow. 61 const uptr meta = MetaShadowBeg(); 62 const uptr meta_size = MetaShadowEnd() - meta; 63 if (!MmapFixedSuperNoReserve(meta, meta_size, "meta shadow")) { 64 Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n"); 65 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n"); 66 Die(); 67 } 68 DontDumpShadow(meta, meta_size); 69 DPrintf("meta shadow: %zx-%zx (%zuGB)\n", 70 meta, meta + meta_size, meta_size >> 30); 71 72 InitializeShadowMemoryPlatform(); 73 } 74 75 static void ProtectRange(uptr beg, uptr end) { 76 CHECK_LE(beg, end); 77 if (beg == end) 78 return; 79 if (beg != (uptr)MmapFixedNoAccess(beg, end - beg)) { 80 Printf("FATAL: ThreadSanitizer can not protect [%zx,%zx]\n", beg, end); 81 Printf("FATAL: Make sure you are not using unlimited stack\n"); 82 Die(); 83 } 84 } 85 86 void CheckAndProtect() { 87 // Ensure that the binary is indeed compiled with -pie. 88 MemoryMappingLayout proc_maps(true); 89 MemoryMappedSegment segment; 90 while (proc_maps.Next(&segment)) { 91 if (IsAppMem(segment.start)) continue; 92 if (segment.start >= HeapMemEnd() && segment.start < HeapEnd()) continue; 93 if (segment.protection == 0) // Zero page or mprotected. 94 continue; 95 if (segment.start >= VdsoBeg()) // vdso 96 break; 97 Printf("FATAL: ThreadSanitizer: unexpected memory mapping %p-%p\n", 98 segment.start, segment.end); 99 Die(); 100 } 101 102 #if defined(__aarch64__) && defined(__APPLE__) 103 ProtectRange(HeapMemEnd(), ShadowBeg()); 104 ProtectRange(ShadowEnd(), MetaShadowBeg()); 105 ProtectRange(MetaShadowEnd(), TraceMemBeg()); 106 #else 107 ProtectRange(LoAppMemEnd(), ShadowBeg()); 108 ProtectRange(ShadowEnd(), MetaShadowBeg()); 109 #ifdef TSAN_MID_APP_RANGE 110 ProtectRange(MetaShadowEnd(), MidAppMemBeg()); 111 ProtectRange(MidAppMemEnd(), TraceMemBeg()); 112 #else 113 ProtectRange(MetaShadowEnd(), TraceMemBeg()); 114 #endif 115 // Memory for traces is mapped lazily in MapThreadTrace. 116 // Protect the whole range for now, so that user does not map something here. 117 ProtectRange(TraceMemBeg(), TraceMemEnd()); 118 ProtectRange(TraceMemEnd(), HeapMemBeg()); 119 ProtectRange(HeapEnd(), HiAppMemBeg()); 120 #endif 121 } 122 #endif 123 124 } // namespace __tsan 125 126 #endif // SANITIZER_POSIX 127