libbacktrace/simple.c

   1 /* simple.c -- The backtrace_simple function.
   2    Copyright (C) 2012-2017 Free Software Foundation, Inc.
   3    Written by Ian Lance Taylor, Google.
   4
   5 Redistribution and use in source and binary forms, with or without
   6 modification, are permitted provided that the following conditions are
   7 met:
   8
   9     (1) Redistributions of source code must retain the above copyright
  10     notice, this list of conditions and the following disclaimer.
  11
  12     (2) Redistributions in binary form must reproduce the above copyright
  13     notice, this list of conditions and the following disclaimer in
  14     the documentation and/or other materials provided with the
  15     distribution.
  16
  17     (3) The name of the author may not be used to
  18     endorse or promote products derived from this software without
  19     specific prior written permission.
  20
  21 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  22 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  23 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  24 DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  25 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  26 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  27 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  29 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  30 IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31 POSSIBILITY OF SUCH DAMAGE.  */
  32
  33 #include "config.h"
  34
  35 #include "unwind.h"
  36 #include "backtrace.h"
  37
  38 /* The simple_backtrace routine.  */
  39
  40 /* Data passed through _Unwind_Backtrace.  */
  41
  42 struct backtrace_simple_data
  43 {
  44   /* Number of frames to skip.  */
  45   int skip;
  46   /* Library state.  */
  47   struct backtrace_state *state;
  48   /* Callback routine.  */
  49   backtrace_simple_callback callback;
  50   /* Error callback routine.  */
  51   backtrace_error_callback error_callback;
  52   /* Data to pass to callback routine.  */
  53   void *data;
  54   /* Value to return from backtrace.  */
  55   int ret;
  56 };
  57
  58 /* Unwind library callback routine.  This is passd to
  59    _Unwind_Backtrace.  */
  60
  61 static _Unwind_Reason_Code
  62 simple_unwind (struct _Unwind_Context *context, void *vdata)
  63 {
  64   struct backtrace_simple_data *bdata = (struct backtrace_simple_data *) vdata;
  65   uintptr_t pc;
  66   int ip_before_insn = 0;
  67
  68 #ifdef HAVE_GETIPINFO
  69   pc = _Unwind_GetIPInfo (context, &ip_before_insn);
  70 #else
  71   pc = _Unwind_GetIP (context);
  72 #endif
  73
  74   if (bdata->skip > 0)
  75     {
  76       --bdata->skip;
  77       return _URC_NO_REASON;
  78     }
  79
  80   if (!ip_before_insn)
  81     --pc;
  82
  83   bdata->ret = bdata->callback (bdata->data, pc);
  84
  85   if (bdata->ret != 0)
  86     return _URC_END_OF_STACK;
  87
  88   return _URC_NO_REASON;
  89 }
  90
  91 /* Get a simple stack backtrace.  */
  92
  93 int
  94 backtrace_simple (struct backtrace_state *state, int skip,
  95                   backtrace_simple_callback callback,
  96                   backtrace_error_callback error_callback, void *data)
  97 {
  98   struct backtrace_simple_data bdata;
  99
 100   bdata.skip = skip + 1;
 101   bdata.state = state;
 102   bdata.callback = callback;
 103   bdata.error_callback = error_callback;
 104   bdata.data = data;
 105   bdata.ret = 0;
 106   _Unwind_Backtrace (simple_unwind, &bdata);
 107   return bdata.ret;
 108 }