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(__sparc__) || defined(__mips__))
21 # define SANITIZER_CAN_FAST_UNWIND 0
22 #elif SANITIZER_WINDOWS
23 # define SANITIZER_CAN_FAST_UNWIND 0
24 #else
25 # define SANITIZER_CAN_FAST_UNWIND 1
26 #endif
27 
28 // Fast unwind is the only option on Mac for now; we will need to
29 // revisit this macro when slow unwind works on Mac, see
30 // https://code.google.com/p/address-sanitizer/issues/detail?id=137
31 #if SANITIZER_MAC
32 # define SANITIZER_CAN_SLOW_UNWIND 0
33 #else
34 # define SANITIZER_CAN_SLOW_UNWIND 1
35 #endif
36 
37 struct StackTrace {
38   const uptr *trace;
39   u32 size;
40   u32 tag;
41 
42   static const int TAG_UNKNOWN = 0;
43   static const int TAG_ALLOC = 1;
44   static const int TAG_DEALLOC = 2;
45   static const int TAG_CUSTOM = 100; // Tool specific tags start here.
46 
StackTraceStackTrace47   StackTrace() : trace(nullptr), size(0), tag(0) {}
StackTraceStackTrace48   StackTrace(const uptr *trace, u32 size) : trace(trace), size(size), tag(0) {}
StackTraceStackTrace49   StackTrace(const uptr *trace, u32 size, u32 tag)
50       : trace(trace), size(size), tag(tag) {}
51 
52   // Prints a symbolized stacktrace, followed by an empty line.
53   void Print() const;
54 
WillUseFastUnwindStackTrace55   static bool WillUseFastUnwind(bool request_fast_unwind) {
56     if (!SANITIZER_CAN_FAST_UNWIND)
57       return false;
58     else if (!SANITIZER_CAN_SLOW_UNWIND)
59       return true;
60     return request_fast_unwind;
61   }
62 
63   static uptr GetCurrentPc();
64   static inline uptr GetPreviousInstructionPc(uptr pc);
65   static uptr GetNextInstructionPc(uptr pc);
66   typedef bool (*SymbolizeCallback)(const void *pc, char *out_buffer,
67                                     int out_size);
68 };
69 
70 // Performance-critical, must be in the header.
71 ALWAYS_INLINE
GetPreviousInstructionPc(uptr pc)72 uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
73 #if defined(__arm__)
74   // Cancel Thumb bit.
75   pc = pc & (~1);
76 #endif
77 #if defined(__powerpc__) || defined(__powerpc64__)
78   // PCs are always 4 byte aligned.
79   return pc - 4;
80 #elif defined(__sparc__) || defined(__mips__)
81   return pc - 8;
82 #else
83   return pc - 1;
84 #endif
85 }
86 
87 // StackTrace that owns the buffer used to store the addresses.
88 struct BufferedStackTrace : public StackTrace {
89   uptr trace_buffer[kStackTraceMax];
90   uptr top_frame_bp;  // Optional bp of a top frame.
91 
BufferedStackTraceBufferedStackTrace92   BufferedStackTrace() : StackTrace(trace_buffer, 0), top_frame_bp(0) {}
93 
94   void Init(const uptr *pcs, uptr cnt, uptr extra_top_pc = 0);
95   void Unwind(u32 max_depth, uptr pc, uptr bp, void *context, uptr stack_top,
96               uptr stack_bottom, bool request_fast_unwind);
97 
98  private:
99   void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
100                        u32 max_depth);
101   void SlowUnwindStack(uptr pc, u32 max_depth);
102   void SlowUnwindStackWithContext(uptr pc, void *context,
103                                   u32 max_depth);
104   void PopStackFrames(uptr count);
105   uptr LocatePcInTrace(uptr pc);
106 
107   BufferedStackTrace(const BufferedStackTrace &);
108   void operator=(const BufferedStackTrace &);
109 };
110 
111 }  // namespace __sanitizer
112 
113 // Use this macro if you want to print stack trace with the caller
114 // of the current function in the top frame.
115 #define GET_CALLER_PC_BP_SP \
116   uptr bp = GET_CURRENT_FRAME();              \
117   uptr pc = GET_CALLER_PC();                  \
118   uptr local_stack;                           \
119   uptr sp = (uptr)&local_stack
120 
121 #define GET_CALLER_PC_BP \
122   uptr bp = GET_CURRENT_FRAME();              \
123   uptr pc = GET_CALLER_PC();
124 
125 // Use this macro if you want to print stack trace with the current
126 // function in the top frame.
127 #define GET_CURRENT_PC_BP_SP \
128   uptr bp = GET_CURRENT_FRAME();              \
129   uptr pc = StackTrace::GetCurrentPc();   \
130   uptr local_stack;                           \
131   uptr sp = (uptr)&local_stack
132 
133 
134 #endif  // SANITIZER_STACKTRACE_H
135