Home | History | Annotate | Line # | Download | only in libbacktrace 
      1 /* simple.c -- The backtrace_simple function.
      2    Copyright (C) 2012-2022 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 passed 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 __attribute__((noinline))
     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 }
    109