libsanitizer/sanitizer_common/sanitizer_stacktrace.h

   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://github.com/google/sanitizers/issues/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
  47   StackTrace() : trace(nullptr), size(0), tag(0) {}
  48   StackTrace(const uptr *trace, u32 size) : trace(trace), size(size), tag(0) {}
  49   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
  55   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
  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
  92   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   void Reset() {
  99     *static_cast<StackTrace *>(this) = StackTrace(trace_buffer, 0);
 100     top_frame_bp = 0;
 101   }
 102
 103  private:
 104   void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
 105                        u32 max_depth);
 106   void SlowUnwindStack(uptr pc, u32 max_depth);
 107   void SlowUnwindStackWithContext(uptr pc, void *context,
 108                                   u32 max_depth);
 109   void PopStackFrames(uptr count);
 110   uptr LocatePcInTrace(uptr pc);
 111
 112   BufferedStackTrace(const BufferedStackTrace &) = delete;
 113   void operator=(const BufferedStackTrace &) = delete;
 114 };
 115
 116 // Check if given pointer points into allocated stack area.
 117 static inline bool IsValidFrame(uptr frame, uptr stack_top, uptr stack_bottom) {
 118   return frame > stack_bottom && frame < stack_top - 2 * sizeof (uhwptr);
 119 }
 120
 121 }  // namespace __sanitizer
 122
 123 // Use this macro if you want to print stack trace with the caller
 124 // of the current function in the top frame.
 125 #define GET_CALLER_PC_BP_SP \
 126   uptr bp = GET_CURRENT_FRAME();              \
 127   uptr pc = GET_CALLER_PC();                  \
 128   uptr local_stack;                           \
 129   uptr sp = (uptr)&local_stack
 130
 131 #define GET_CALLER_PC_BP \
 132   uptr bp = GET_CURRENT_FRAME();              \
 133   uptr pc = GET_CALLER_PC();
 134
 135 // Use this macro if you want to print stack trace with the current
 136 // function in the top frame.
 137 #define GET_CURRENT_PC_BP_SP \
 138   uptr bp = GET_CURRENT_FRAME();              \
 139   uptr pc = StackTrace::GetCurrentPc();   \
 140   uptr local_stack;                           \
 141   uptr sp = (uptr)&local_stack
 142
 143
 144 #endif  // SANITIZER_STACKTRACE_H