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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
45alignas(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