1 //===-- sanitizer_stacktrace.h ----------------------------------*- C++ -*-===//
2 //
3 // This file is distributed under the University of Illinois Open Source
4 // License. See LICENSE.TXT for details.
5 //
6 //===----------------------------------------------------------------------===//
7 //
8 // This file is shared between AddressSanitizer and ThreadSanitizer
9 // run-time libraries.
10 //===----------------------------------------------------------------------===//
11 #ifndef SANITIZER_STACKTRACE_H
12 #define SANITIZER_STACKTRACE_H
13
14 #include "sanitizer_internal_defs.h"
15
16 namespace __sanitizer {
17
18 static const u32 kStackTraceMax = 256;
19
20 #if SANITIZER_LINUX && defined(__mips__)
21 # define SANITIZER_CAN_FAST_UNWIND 0
22 #elif SANITIZER_WINDOWS
23 # define SANITIZER_CAN_FAST_UNWIND 0
24 #elif SANITIZER_OPENBSD
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 || SANITIZER_OPENBSD || SANITIZER_RTEMS
34 # define SANITIZER_CAN_SLOW_UNWIND 0
35 #else
36 # define SANITIZER_CAN_SLOW_UNWIND 1
37 #endif
38
39 struct 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
StackTraceStackTrace49 StackTrace() : trace(nullptr), size(0), tag(0) {}
StackTraceStackTrace50 StackTrace(const uptr *trace, u32 size) : trace(trace), size(size), tag(0) {}
StackTraceStackTrace51 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
WillUseFastUnwindStackTrace57 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.
73 ALWAYS_INLINE
GetPreviousInstructionPc(uptr pc)74 uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
75 #if defined(__arm__)
76 // T32 (Thumb) branch instructions might be 16 or 32 bit long,
77 // so we return (pc-2) in that case in order to be safe.
78 // For A32 mode we return (pc-4) because all instructions are 32 bit long.
79 return (pc - 3) & (~1);
80 #elif defined(__powerpc__) || defined(__powerpc64__) || defined(__aarch64__)
81 // PCs are always 4 byte aligned.
82 return pc - 4;
83 #elif defined(__sparc__) || defined(__mips__)
84 return pc - 8;
85 #else
86 return pc - 1;
87 #endif
88 }
89
90 // StackTrace that owns the buffer used to store the addresses.
91 struct BufferedStackTrace : public StackTrace {
92 uptr trace_buffer[kStackTraceMax];
93 uptr top_frame_bp; // Optional bp of a top frame.
94
BufferedStackTraceBufferedStackTrace95 BufferedStackTrace() : StackTrace(trace_buffer, 0), top_frame_bp(0) {}
96
97 void Init(const uptr *pcs, uptr cnt, uptr extra_top_pc = 0);
98 void Unwind(u32 max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
99 uptr stack_bottom, bool request_fast_unwind);
100
ResetBufferedStackTrace101 void Reset() {
102 *static_cast<StackTrace *>(this) = StackTrace(trace_buffer, 0);
103 top_frame_bp = 0;
104 }
105
106 private:
107 void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
108 u32 max_depth);
109 void SlowUnwindStack(uptr pc, u32 max_depth);
110 void SlowUnwindStackWithContext(uptr pc, void *context,
111 u32 max_depth);
112 void PopStackFrames(uptr count);
113 uptr LocatePcInTrace(uptr pc);
114
115 BufferedStackTrace(const BufferedStackTrace &) = delete;
116 void operator=(const BufferedStackTrace &) = delete;
117 };
118
119 // Check if given pointer points into allocated stack area.
IsValidFrame(uptr frame,uptr stack_top,uptr stack_bottom)120 static inline bool IsValidFrame(uptr frame, uptr stack_top, uptr stack_bottom) {
121 return frame > stack_bottom && frame < stack_top - 2 * sizeof (uhwptr);
122 }
123
124 } // namespace __sanitizer
125
126 // Use this macro if you want to print stack trace with the caller
127 // of the current function in the top frame.
128 #define GET_CALLER_PC_BP_SP \
129 uptr bp = GET_CURRENT_FRAME(); \
130 uptr pc = GET_CALLER_PC(); \
131 uptr local_stack; \
132 uptr sp = (uptr)&local_stack
133
134 #define GET_CALLER_PC_BP \
135 uptr bp = GET_CURRENT_FRAME(); \
136 uptr pc = GET_CALLER_PC();
137
138 // Use this macro if you want to print stack trace with the current
139 // function in the top frame.
140 #define GET_CURRENT_PC_BP_SP \
141 uptr bp = GET_CURRENT_FRAME(); \
142 uptr pc = StackTrace::GetCurrentPc(); \
143 uptr local_stack; \
144 uptr sp = (uptr)&local_stack
145
146
147 #endif // SANITIZER_STACKTRACE_H
148