1//===-- sanitizer_stacktrace.h ----------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is shared between AddressSanitizer and ThreadSanitizer
11// run-time libraries.
12//===----------------------------------------------------------------------===//
13#ifndef SANITIZER_STACKTRACE_H
14#define SANITIZER_STACKTRACE_H
15
16#include "sanitizer_internal_defs.h"
17
18namespace __sanitizer {
19
20static const u32 kStackTraceMax = 256;
21
22#if SANITIZER_LINUX &&  (defined(__sparc__) || defined(__mips__))
23# define SANITIZER_CAN_FAST_UNWIND 0
24#elif SANITIZER_WINDOWS
25# define SANITIZER_CAN_FAST_UNWIND 0
26#else
27# define SANITIZER_CAN_FAST_UNWIND 1
28#endif
29
30// Fast unwind is the only option on Mac for now; we will need to
31// revisit this macro when slow unwind works on Mac, see
32// https://github.com/google/sanitizers/issues/137
33#if SANITIZER_MAC
34# define SANITIZER_CAN_SLOW_UNWIND 0
35#else
36# define SANITIZER_CAN_SLOW_UNWIND 1
37#endif
38
39struct StackTrace {
40  const uptr *trace;
41  u32 size;
42  u32 tag;
43
44  static const int TAG_UNKNOWN = 0;
45  static const int TAG_ALLOC = 1;
46  static const int TAG_DEALLOC = 2;
47  static const int TAG_CUSTOM = 100; // Tool specific tags start here.
48
49  StackTrace() : trace(nullptr), size(0), tag(0) {}
50  StackTrace(const uptr *trace, u32 size) : trace(trace), size(size), tag(0) {}
51  StackTrace(const uptr *trace, u32 size, u32 tag)
52      : trace(trace), size(size), tag(tag) {}
53
54  // Prints a symbolized stacktrace, followed by an empty line.
55  void Print() const;
56
57  static bool WillUseFastUnwind(bool request_fast_unwind) {
58    if (!SANITIZER_CAN_FAST_UNWIND)
59      return false;
60    else if (!SANITIZER_CAN_SLOW_UNWIND)
61      return true;
62    return request_fast_unwind;
63  }
64
65  static uptr GetCurrentPc();
66  static inline uptr GetPreviousInstructionPc(uptr pc);
67  static uptr GetNextInstructionPc(uptr pc);
68  typedef bool (*SymbolizeCallback)(const void *pc, char *out_buffer,
69                                    int out_size);
70};
71
72// Performance-critical, must be in the header.
73ALWAYS_INLINE
74uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
75#if defined(__arm__)
76  // Cancel Thumb bit.
77  pc = pc & (~1);
78#endif
79#if defined(__powerpc__) || defined(__powerpc64__)
80  // PCs are always 4 byte aligned.
81  return pc - 4;
82#elif defined(__sparc__) || defined(__mips__)
83  return pc - 8;
84#else
85  return pc - 1;
86#endif
87}
88
89// StackTrace that owns the buffer used to store the addresses.
90struct BufferedStackTrace : public StackTrace {
91  uptr trace_buffer[kStackTraceMax];
92  uptr top_frame_bp;  // Optional bp of a top frame.
93
94  BufferedStackTrace() : StackTrace(trace_buffer, 0), top_frame_bp(0) {}
95
96  void Init(const uptr *pcs, uptr cnt, uptr extra_top_pc = 0);
97  void Unwind(u32 max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
98              uptr stack_bottom, bool request_fast_unwind);
99
100 private:
101  void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
102                       u32 max_depth);
103  void SlowUnwindStack(uptr pc, u32 max_depth);
104  void SlowUnwindStackWithContext(uptr pc, void *context,
105                                  u32 max_depth);
106  void PopStackFrames(uptr count);
107  uptr LocatePcInTrace(uptr pc);
108
109  BufferedStackTrace(const BufferedStackTrace &);
110  void operator=(const BufferedStackTrace &);
111};
112
113}  // namespace __sanitizer
114
115// Use this macro if you want to print stack trace with the caller
116// of the current function in the top frame.
117#define GET_CALLER_PC_BP_SP \
118  uptr bp = GET_CURRENT_FRAME();              \
119  uptr pc = GET_CALLER_PC();                  \
120  uptr local_stack;                           \
121  uptr sp = (uptr)&local_stack
122
123#define GET_CALLER_PC_BP \
124  uptr bp = GET_CURRENT_FRAME();              \
125  uptr pc = GET_CALLER_PC();
126
127// Use this macro if you want to print stack trace with the current
128// function in the top frame.
129#define GET_CURRENT_PC_BP_SP \
130  uptr bp = GET_CURRENT_FRAME();              \
131  uptr pc = StackTrace::GetCurrentPc();   \
132  uptr local_stack;                           \
133  uptr sp = (uptr)&local_stack
134
135
136#endif  // SANITIZER_STACKTRACE_H
137