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 defined(__sparc__) || (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
  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.
  73 ALWAYS_INLINE
  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
  95   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
 101   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.
 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