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