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sanitizer_stacktrace.h revision 1.8 
      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 
     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
    148