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
24namespace __tsan {
25
26#ifndef SANITIZER_GO
27void 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
104static 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
115void 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