1//===-- tsan_suppressions.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//===----------------------------------------------------------------------===//
12
13#include "tsan_suppressions.h"
14
15#include "sanitizer_common/sanitizer_common.h"
16#include "sanitizer_common/sanitizer_libc.h"
17#include "sanitizer_common/sanitizer_placement_new.h"
18#include "sanitizer_common/sanitizer_suppressions.h"
19#include "tsan_flags.h"
20#include "tsan_mman.h"
21#include "tsan_platform.h"
22#include "tsan_rtl.h"
23
24#if !SANITIZER_GO
25// Suppressions for true/false positives in standard libraries.
26static const char *const std_suppressions =
27// Libstdc++ 4.4 has data races in std::string.
28// See http://crbug.com/181502 for an example.
29"race:^_M_rep$\n"
30"race:^_M_is_leaked$\n"
31// False positive when using std <thread>.
32// Happens because we miss atomic synchronization in libstdc++.
33// See http://llvm.org/bugs/show_bug.cgi?id=17066 for details.
34"race:std::_Sp_counted_ptr_inplace<std::thread::_Impl\n";
35
36// Can be overriden in frontend.
37SANITIZER_WEAK_DEFAULT_IMPL
38const char *__tsan_default_suppressions() {
39  return 0;
40}
41#endif
42
43namespace __tsan {
44
45ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)];
46static SuppressionContext *suppression_ctx = nullptr;
47static const char *kSuppressionTypes[] = {
48    kSuppressionRace,   kSuppressionRaceTop, kSuppressionMutex,
49    kSuppressionThread, kSuppressionSignal, kSuppressionLib,
50    kSuppressionDeadlock};
51
52void InitializeSuppressions() {
53  CHECK_EQ(nullptr, suppression_ctx);
54  suppression_ctx = new (suppression_placeholder)
55      SuppressionContext(kSuppressionTypes, ARRAY_SIZE(kSuppressionTypes));
56  suppression_ctx->ParseFromFile(flags()->suppressions);
57#if !SANITIZER_GO
58  suppression_ctx->Parse(__tsan_default_suppressions());
59  suppression_ctx->Parse(std_suppressions);
60#endif
61}
62
63SuppressionContext *Suppressions() {
64  CHECK(suppression_ctx);
65  return suppression_ctx;
66}
67
68static const char *conv(ReportType typ) {
69  switch (typ) {
70    case ReportTypeRace:
71    case ReportTypeVptrRace:
72    case ReportTypeUseAfterFree:
73    case ReportTypeVptrUseAfterFree:
74    case ReportTypeExternalRace:
75      return kSuppressionRace;
76    case ReportTypeThreadLeak:
77      return kSuppressionThread;
78    case ReportTypeMutexDestroyLocked:
79    case ReportTypeMutexDoubleLock:
80    case ReportTypeMutexInvalidAccess:
81    case ReportTypeMutexBadUnlock:
82    case ReportTypeMutexBadReadLock:
83    case ReportTypeMutexBadReadUnlock:
84    case ReportTypeMutexHeldWrongContext:
85      return kSuppressionMutex;
86    case ReportTypeSignalUnsafe:
87    case ReportTypeErrnoInSignal:
88      return kSuppressionSignal;
89    case ReportTypeDeadlock:
90      return kSuppressionDeadlock;
91    // No default case so compiler warns us if we miss one
92  }
93  UNREACHABLE("missing case");
94}
95
96static uptr IsSuppressed(const char *stype, const AddressInfo &info,
97    Suppression **sp) {
98  if (suppression_ctx->Match(info.function, stype, sp) ||
99      suppression_ctx->Match(info.file, stype, sp) ||
100      suppression_ctx->Match(info.module, stype, sp)) {
101    VPrintf(2, "ThreadSanitizer: matched suppression '%s'\n", (*sp)->templ);
102    atomic_fetch_add(&(*sp)->hit_count, 1, memory_order_relaxed);
103    return info.address;
104  }
105  return 0;
106}
107
108uptr IsSuppressed(ReportType typ, const ReportStack *stack, Suppression **sp) {
109  CHECK(suppression_ctx);
110  if (!suppression_ctx->SuppressionCount() || stack == 0 ||
111      !stack->suppressable)
112    return 0;
113  const char *stype = conv(typ);
114  if (0 == internal_strcmp(stype, kSuppressionNone))
115    return 0;
116  for (const SymbolizedStack *frame = stack->frames; frame;
117      frame = frame->next) {
118    uptr pc = IsSuppressed(stype, frame->info, sp);
119    if (pc != 0)
120      return pc;
121  }
122  if (0 == internal_strcmp(stype, kSuppressionRace) && stack->frames != nullptr)
123    return IsSuppressed(kSuppressionRaceTop, stack->frames->info, sp);
124  return 0;
125}
126
127uptr IsSuppressed(ReportType typ, const ReportLocation *loc, Suppression **sp) {
128  CHECK(suppression_ctx);
129  if (!suppression_ctx->SuppressionCount() || loc == 0 ||
130      loc->type != ReportLocationGlobal || !loc->suppressable)
131    return 0;
132  const char *stype = conv(typ);
133  if (0 == internal_strcmp(stype, kSuppressionNone))
134    return 0;
135  Suppression *s;
136  const DataInfo &global = loc->global;
137  if (suppression_ctx->Match(global.name, stype, &s) ||
138      suppression_ctx->Match(global.module, stype, &s)) {
139      VPrintf(2, "ThreadSanitizer: matched suppression '%s'\n", s->templ);
140      atomic_fetch_add(&s->hit_count, 1, memory_order_relaxed);
141      *sp = s;
142      return global.start;
143  }
144  return 0;
145}
146
147void PrintMatchedSuppressions() {
148  InternalMmapVector<Suppression *> matched;
149  CHECK(suppression_ctx);
150  suppression_ctx->GetMatched(&matched);
151  if (!matched.size())
152    return;
153  int hit_count = 0;
154  for (uptr i = 0; i < matched.size(); i++)
155    hit_count += atomic_load_relaxed(&matched[i]->hit_count);
156  Printf("ThreadSanitizer: Matched %d suppressions (pid=%d):\n", hit_count,
157         (int)internal_getpid());
158  for (uptr i = 0; i < matched.size(); i++) {
159    Printf("%d %s:%s\n", atomic_load_relaxed(&matched[i]->hit_count),
160           matched[i]->type, matched[i]->templ);
161  }
162}
163}  // namespace __tsan
164