1 //===-- tsan_platform_posix.cc --------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of ThreadSanitizer (TSan), a race detector.
11 //
12 // POSIX-specific code.
13 //===----------------------------------------------------------------------===//
14
15 #include "sanitizer_common/sanitizer_platform.h"
16 #if SANITIZER_POSIX
17
18 #include "sanitizer_common/sanitizer_common.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 #ifndef SANITIZER_GO
InitializeShadowMemory()27 void InitializeShadowMemory() {
28 // Map memory shadow.
29 uptr shadow =
30 (uptr)MmapFixedNoReserve(ShadowBeg(), ShadowEnd() - ShadowBeg(),
31 "shadow");
32 if (shadow != ShadowBeg()) {
33 Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
34 Printf("FATAL: Make sure to compile with -fPIE and "
35 "to link with -pie (%p, %p).\n", shadow, ShadowBeg());
36 Die();
37 }
38 // This memory range is used for thread stacks and large user mmaps.
39 // Frequently a thread uses only a small part of stack and similarly
40 // a program uses a small part of large mmap. On some programs
41 // we see 20% memory usage reduction without huge pages for this range.
42 // FIXME: don't use constants here.
43 #if defined(__x86_64__)
44 const uptr kMadviseRangeBeg = 0x7f0000000000ull;
45 const uptr kMadviseRangeSize = 0x010000000000ull;
46 #elif defined(__mips64)
47 const uptr kMadviseRangeBeg = 0xff00000000ull;
48 const uptr kMadviseRangeSize = 0x0100000000ull;
49 #elif defined(__aarch64__)
50 uptr kMadviseRangeBeg = 0;
51 uptr kMadviseRangeSize = 0;
52 if (vmaSize == 39) {
53 kMadviseRangeBeg = 0x7d00000000ull;
54 kMadviseRangeSize = 0x0300000000ull;
55 } else if (vmaSize == 42) {
56 kMadviseRangeBeg = 0x3f000000000ull;
57 kMadviseRangeSize = 0x01000000000ull;
58 } else {
59 DCHECK(0);
60 }
61 #elif defined(__powerpc64__)
62 uptr kMadviseRangeBeg = 0;
63 uptr kMadviseRangeSize = 0;
64 if (vmaSize == 44) {
65 kMadviseRangeBeg = 0x0f60000000ull;
66 kMadviseRangeSize = 0x0010000000ull;
67 } else if (vmaSize == 46) {
68 kMadviseRangeBeg = 0x3f0000000000ull;
69 kMadviseRangeSize = 0x010000000000ull;
70 } else {
71 DCHECK(0);
72 }
73 #endif
74 NoHugePagesInRegion(MemToShadow(kMadviseRangeBeg),
75 kMadviseRangeSize * kShadowMultiplier);
76 // Meta shadow is compressing and we don't flush it,
77 // so it makes sense to mark it as NOHUGEPAGE to not over-allocate memory.
78 // On one program it reduces memory consumption from 5GB to 2.5GB.
79 NoHugePagesInRegion(MetaShadowBeg(), MetaShadowEnd() - MetaShadowBeg());
80 if (common_flags()->use_madv_dontdump)
81 DontDumpShadowMemory(ShadowBeg(), ShadowEnd() - ShadowBeg());
82 DPrintf("memory shadow: %zx-%zx (%zuGB)\n",
83 ShadowBeg(), ShadowEnd(),
84 (ShadowEnd() - ShadowBeg()) >> 30);
85
86 // Map meta shadow.
87 uptr meta_size = MetaShadowEnd() - MetaShadowBeg();
88 uptr meta =
89 (uptr)MmapFixedNoReserve(MetaShadowBeg(), meta_size, "meta shadow");
90 if (meta != MetaShadowBeg()) {
91 Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
92 Printf("FATAL: Make sure to compile with -fPIE and "
93 "to link with -pie (%p, %p).\n", meta, MetaShadowBeg());
94 Die();
95 }
96 if (common_flags()->use_madv_dontdump)
97 DontDumpShadowMemory(meta, meta_size);
98 DPrintf("meta shadow: %zx-%zx (%zuGB)\n",
99 meta, meta + meta_size, meta_size >> 30);
100
101 InitializeShadowMemoryPlatform();
102 }
103
ProtectRange(uptr beg,uptr end)104 static void ProtectRange(uptr beg, uptr end) {
105 CHECK_LE(beg, end);
106 if (beg == end)
107 return;
108 if (beg != (uptr)MmapNoAccess(beg, end - beg)) {
109 Printf("FATAL: ThreadSanitizer can not protect [%zx,%zx]\n", beg, end);
110 Printf("FATAL: Make sure you are not using unlimited stack\n");
111 Die();
112 }
113 }
114
CheckAndProtect()115 void CheckAndProtect() {
116 // Ensure that the binary is indeed compiled with -pie.
117 MemoryMappingLayout proc_maps(true);
118 uptr p, end, prot;
119 while (proc_maps.Next(&p, &end, 0, 0, 0, &prot)) {
120 if (IsAppMem(p))
121 continue;
122 if (p >= HeapMemEnd() &&
123 p < HeapEnd())
124 continue;
125 if (prot == 0) // Zero page or mprotected.
126 continue;
127 if (p >= VdsoBeg()) // vdso
128 break;
129 Printf("FATAL: ThreadSanitizer: unexpected memory mapping %p-%p\n", p, end);
130 Die();
131 }
132
133 ProtectRange(LoAppMemEnd(), ShadowBeg());
134 ProtectRange(ShadowEnd(), MetaShadowBeg());
135 #ifdef TSAN_MID_APP_RANGE
136 ProtectRange(MetaShadowEnd(), MidAppMemBeg());
137 ProtectRange(MidAppMemEnd(), TraceMemBeg());
138 #else
139 ProtectRange(MetaShadowEnd(), TraceMemBeg());
140 #endif
141 // Memory for traces is mapped lazily in MapThreadTrace.
142 // Protect the whole range for now, so that user does not map something here.
143 ProtectRange(TraceMemBeg(), TraceMemEnd());
144 ProtectRange(TraceMemEnd(), HeapMemBeg());
145 ProtectRange(HeapEnd(), HiAppMemBeg());
146 }
147 #endif
148
149 } // namespace __tsan
150
151 #endif // SANITIZER_POSIX
152