lib/backtrace.c

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2013 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18 #include <inttypes.h>
  19
  20 #include "backtrace.h"
  21 #include "openvswitch/vlog.h"
  22
  23 VLOG_DEFINE_THIS_MODULE(backtrace);
  24
  25 #ifdef HAVE_BACKTRACE
  26 #include <execinfo.h>
  27 void
  28 backtrace_capture(struct backtrace *b)
  29 {
  30     void *frames[BACKTRACE_MAX_FRAMES];
  31     int i;
  32
  33     b->n_frames = backtrace(frames, BACKTRACE_MAX_FRAMES);
  34     for (i = 0; i < b->n_frames; i++) {
  35         b->frames[i] = (uintptr_t) frames[i];
  36     }
  37 }
  38
  39 #else
  40 void
  41 backtrace_capture(struct backtrace *backtrace)
  42 {
  43     backtrace->n_frames = 0;
  44 }
  45 #endif
  46
  47 static char *
  48 backtrace_format(const struct backtrace *b, struct ds *ds)
  49 {
  50     if (b->n_frames) {
  51         int i;
  52
  53         ds_put_cstr(ds, " (backtrace:");
  54         for (i = 0; i < b->n_frames; i++) {
  55             ds_put_format(ds, " 0x%08"PRIxPTR, b->frames[i]);
  56         }
  57         ds_put_cstr(ds, ")");
  58     }
  59
  60     return ds_cstr(ds);
  61 }
  62
  63 void
  64 log_backtrace_at(const char *msg, const char *where)
  65 {
  66     struct backtrace b;
  67     struct ds ds = DS_EMPTY_INITIALIZER;
  68
  69     backtrace_capture(&b);
  70     if (msg) {
  71         ds_put_format(&ds, "%s ", msg);
  72     }
  73
  74     ds_put_cstr(&ds, where);
  75     VLOG_ERR("%s", backtrace_format(&b, &ds));
  76
  77     ds_destroy(&ds);
  78 }