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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)MmapFixedNoAccess(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