1 /* fileline.c -- Get file and line number information in a backtrace.
2 Copyright (C) 2012 Free Software Foundation, Inc.
3 Written by Ian Lance Taylor, Google.
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are
9 (1) Redistributions of source code must retain the above copyright
10 notice, this list of conditions and the following disclaimer.
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
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.
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. */
35 #include <sys/types.h>
39 #include "backtrace.h"
42 /* Initialize the fileline information from the executable. Returns 1
43 on success, 0 on failure. */
46 fileline_initialize (struct backtrace_state *state,
47 backtrace_error_callback error_callback, void *data)
53 failed = state->fileline_initialization_failed;
57 /* Use __sync_bool_compare_and_swap to do an atomic load. */
58 while (!__sync_bool_compare_and_swap
59 (&state->fileline_initialization_failed, failed, failed))
60 failed = state->fileline_initialization_failed;
65 error_callback (data, "failed to read executable information", 0);
69 fileline_fn = state->fileline_fn;
72 while (!__sync_bool_compare_and_swap (&state->fileline_fn, fileline_fn,
74 fileline_fn = state->fileline_fn;
76 if (fileline_fn != NULL)
79 /* We have not initialized the information. Do it now. */
81 if (state->filename != NULL)
82 descriptor = backtrace_open (state->filename, error_callback, data);
84 descriptor = backtrace_open ("/proc/self/exe", error_callback, data);
90 if (!backtrace_initialize (state, descriptor, error_callback, data,
98 state->fileline_initialization_failed = 1;
100 __sync_bool_compare_and_swap (&state->fileline_initialization_failed,
105 if (!state->threaded)
106 state->fileline_fn = fileline_fn;
109 __sync_bool_compare_and_swap (&state->fileline_fn, NULL, fileline_fn);
111 /* At this point we know that state->fileline_fn is not NULL.
112 Either we stored our value, or some other thread stored its
113 value. If some other thread stored its value, we leak the
114 one we just initialized. Either way, state->fileline_fn is
115 initialized. The compare_and_swap is a full memory barrier,
116 so we should have full access to that value even if it was
117 created by another thread. */
123 /* Given a PC, find the file name, line number, and function name. */
126 backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc,
127 backtrace_full_callback callback,
128 backtrace_error_callback error_callback, void *data)
130 if (!fileline_initialize (state, error_callback, data))
133 if (state->fileline_initialization_failed)
136 return state->fileline_fn (state, pc, callback, error_callback, data);
139 /* Given a PC, find the symbol for it, and its value. */
142 backtrace_syminfo (struct backtrace_state *state, uintptr_t pc,
143 backtrace_syminfo_callback callback,
144 backtrace_error_callback error_callback, void *data)
146 if (!fileline_initialize (state, error_callback, data))
149 if (state->fileline_initialization_failed)
152 state->syminfo_fn (state, pc, callback, error_callback, data);