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.
26 static 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.
37 SANITIZER_WEAK_DEFAULT_IMPL
38 const char *__tsan_default_suppressions() {
39   return 0;
40 }
41 #endif
42 
43 namespace __tsan {
44 
45 ALIGNED(64) static char suppression_placeholder[sizeof(SuppressionContext)];
46 static SuppressionContext *suppression_ctx = nullptr;
47 static const char *kSuppressionTypes[] = {
48     kSuppressionRace,   kSuppressionRaceTop, kSuppressionMutex,
49     kSuppressionThread, kSuppressionSignal, kSuppressionLib,
50     kSuppressionDeadlock};
51 
52 void 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 
63 SuppressionContext *Suppressions() {
64   CHECK(suppression_ctx);
65   return suppression_ctx;
66 }
67 
68 static 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       return kSuppressionMutex;
85     case ReportTypeSignalUnsafe:
86     case ReportTypeErrnoInSignal:
87       return kSuppressionSignal;
88     case ReportTypeDeadlock:
89       return kSuppressionDeadlock;
90     // No default case so compiler warns us if we miss one
91   }
92   UNREACHABLE("missing case");
93 }
94 
95 static uptr IsSuppressed(const char *stype, const AddressInfo &info,
96     Suppression **sp) {
97   if (suppression_ctx->Match(info.function, stype, sp) ||
98       suppression_ctx->Match(info.file, stype, sp) ||
99       suppression_ctx->Match(info.module, stype, sp)) {
100     VPrintf(2, "ThreadSanitizer: matched suppression '%s'\n", (*sp)->templ);
101     atomic_fetch_add(&(*sp)->hit_count, 1, memory_order_relaxed);
102     return info.address;
103   }
104   return 0;
105 }
106 
107 uptr IsSuppressed(ReportType typ, const ReportStack *stack, Suppression **sp) {
108   CHECK(suppression_ctx);
109   if (!suppression_ctx->SuppressionCount() || stack == 0 ||
110       !stack->suppressable)
111     return 0;
112   const char *stype = conv(typ);
113   if (0 == internal_strcmp(stype, kSuppressionNone))
114     return 0;
115   for (const SymbolizedStack *frame = stack->frames; frame;
116       frame = frame->next) {
117     uptr pc = IsSuppressed(stype, frame->info, sp);
118     if (pc != 0)
119       return pc;
120   }
121   if (0 == internal_strcmp(stype, kSuppressionRace) && stack->frames != nullptr)
122     return IsSuppressed(kSuppressionRaceTop, stack->frames->info, sp);
123   return 0;
124 }
125 
126 uptr IsSuppressed(ReportType typ, const ReportLocation *loc, Suppression **sp) {
127   CHECK(suppression_ctx);
128   if (!suppression_ctx->SuppressionCount() || loc == 0 ||
129       loc->type != ReportLocationGlobal || !loc->suppressable)
130     return 0;
131   const char *stype = conv(typ);
132   if (0 == internal_strcmp(stype, kSuppressionNone))
133     return 0;
134   Suppression *s;
135   const DataInfo &global = loc->global;
136   if (suppression_ctx->Match(global.name, stype, &s) ||
137       suppression_ctx->Match(global.module, stype, &s)) {
138       VPrintf(2, "ThreadSanitizer: matched suppression '%s'\n", s->templ);
139       atomic_fetch_add(&s->hit_count, 1, memory_order_relaxed);
140       *sp = s;
141       return global.start;
142   }
143   return 0;
144 }
145 
146 void PrintMatchedSuppressions() {
147   InternalMmapVector<Suppression *> matched;
148   CHECK(suppression_ctx);
149   suppression_ctx->GetMatched(&matched);
150   if (!matched.size())
151     return;
152   int hit_count = 0;
153   for (uptr i = 0; i < matched.size(); i++)
154     hit_count += atomic_load_relaxed(&matched[i]->hit_count);
155   Printf("ThreadSanitizer: Matched %d suppressions (pid=%d):\n", hit_count,
156          (int)internal_getpid());
157   for (uptr i = 0; i < matched.size(); i++) {
158     Printf("%d %s:%s\n", atomic_load_relaxed(&matched[i]->hit_count),
159            matched[i]->type, matched[i]->templ);
160   }
161 }
162 }  // namespace __tsan
163