1 //===-- tsan_trace.h --------------------------------------------*- C++ -*-===//
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 #ifndef TSAN_TRACE_H
13 #define TSAN_TRACE_H
14 
15 #include "tsan_defs.h"
16 #include "tsan_stack_trace.h"
17 #include "tsan_mutexset.h"
18 
19 namespace __tsan {
20 
21 const int kTracePartSizeBits = 13;
22 const int kTracePartSize = 1 << kTracePartSizeBits;
23 const int kTraceParts = 2 * 1024 * 1024 / kTracePartSize;
24 const int kTraceSize = kTracePartSize * kTraceParts;
25 
26 // Must fit into 3 bits.
27 enum EventType {
28   EventTypeMop,
29   EventTypeFuncEnter,
30   EventTypeFuncExit,
31   EventTypeLock,
32   EventTypeUnlock,
33   EventTypeRLock,
34   EventTypeRUnlock
35 };
36 
37 // Represents a thread event (from most significant bit):
38 // u64 typ  : 3;   // EventType.
39 // u64 addr : 61;  // Associated pc.
40 typedef u64 Event;
41 
42 const uptr kEventPCBits = 61;
43 
44 struct TraceHeader {
45 #if !SANITIZER_GO
46   BufferedStackTrace stack0;  // Start stack for the trace.
47 #else
48   VarSizeStackTrace stack0;
49 #endif
50   u64        epoch0;  // Start epoch for the trace.
51   MutexSet   mset0;
52 
53   TraceHeader() : stack0(), epoch0() {}
54 };
55 
56 struct Trace {
57   Mutex mtx;
58 #if !SANITIZER_GO
59   // Must be last to catch overflow as paging fault.
60   // Go shadow stack is dynamically allocated.
61   uptr shadow_stack[kShadowStackSize];
62 #endif
63   // Must be the last field, because we unmap the unused part in
64   // CreateThreadContext.
65   TraceHeader headers[kTraceParts];
66 
67   Trace() : mtx(MutexTypeTrace) {}
68 };
69 
70 }  // namespace __tsan
71 
72 #endif  // TSAN_TRACE_H
73