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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2013, Digium, Inc.
*
* Matt Jordan <mjordan@digium.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
* \brief Asterisk backtrace generation
*
* This file provides backtrace generation utilities
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/backtrace.h"
#include "asterisk/utils.h"
#include "asterisk/strings.h"
#ifdef HAVE_BKTR
#include <execinfo.h>
#if defined(HAVE_DLADDR) && defined(HAVE_BFD) && defined(BETTER_BACKTRACES)
#include <dlfcn.h>
#include <bfd.h>
#endif
struct ast_bt *__ast_bt_create(void)
{
struct ast_bt *bt = ast_std_calloc(1, sizeof(*bt));
if (!bt) {
return NULL;
}
bt->alloced = 1;
ast_bt_get_addresses(bt);
return bt;
}
int __ast_bt_get_addresses(struct ast_bt *bt)
{
bt->num_frames = backtrace(bt->addresses, AST_MAX_BT_FRAMES);
return 0;
}
void *__ast_bt_destroy(struct ast_bt *bt)
{
if (bt && bt->alloced) {
ast_std_free(bt);
}
return NULL;
}
char **__ast_bt_get_symbols(void **addresses, size_t num_frames)
{
char **strings;
#if defined(BETTER_BACKTRACES)
int stackfr;
bfd *bfdobj; /* bfd.h */
Dl_info dli; /* dlfcn.h */
long allocsize;
asymbol **syms = NULL; /* bfd.h */
bfd_vma offset; /* bfd.h */
const char *lastslash;
asection *section;
const char *file, *func;
unsigned int line;
char address_str[128];
char msg[1024];
size_t strings_size;
size_t *eachlen;
#endif
#if defined(BETTER_BACKTRACES)
strings_size = num_frames * sizeof(*strings);
eachlen = ast_std_calloc(num_frames, sizeof(*eachlen));
strings = ast_std_calloc(num_frames, sizeof(*strings));
if (!eachlen || !strings) {
ast_std_free(eachlen);
ast_std_free(strings);
return NULL;
}
for (stackfr = 0; stackfr < num_frames; stackfr++) {
int found = 0, symbolcount;
msg[0] = '\0';
if (!dladdr(addresses[stackfr], &dli)) {
continue;
}
if (strcmp(dli.dli_fname, "asterisk") == 0) {
char asteriskpath[256];
if (!(dli.dli_fname = ast_utils_which("asterisk", asteriskpath, sizeof(asteriskpath)))) {
/* This will fail to find symbols */
dli.dli_fname = "asterisk";
}
}
lastslash = strrchr(dli.dli_fname, '/');
if ((bfdobj = bfd_openr(dli.dli_fname, NULL)) &&
bfd_check_format(bfdobj, bfd_object) &&
(allocsize = bfd_get_symtab_upper_bound(bfdobj)) > 0 &&
(syms = ast_std_malloc(allocsize)) &&
(symbolcount = bfd_canonicalize_symtab(bfdobj, syms))) {
if (bfdobj->flags & DYNAMIC) {
offset = addresses[stackfr] - dli.dli_fbase;
} else {
offset = addresses[stackfr] - (void *) 0;
}
for (section = bfdobj->sections; section; section = section->next) {
if (!(bfd_get_section_flags(bfdobj, section) & SEC_ALLOC) ||
section->vma > offset ||
section->size + section->vma < offset) {
continue;
}
if (!bfd_find_nearest_line(bfdobj, section, syms, offset - section->vma, &file, &func, &line)) {
continue;
}
/* file can possibly be null even with a success result from bfd_find_nearest_line */
file = file ? file : "";
/* Stack trace output */
found++;
if ((lastslash = strrchr(file, '/'))) {
const char *prevslash;
for (prevslash = lastslash - 1; *prevslash != '/' && prevslash >= file; prevslash--) {
}
if (prevslash >= file) {
lastslash = prevslash;
}
}
if (dli.dli_saddr == NULL) {
address_str[0] = '\0';
} else {
snprintf(address_str, sizeof(address_str), " (%p+%lX)",
dli.dli_saddr,
(unsigned long) (addresses[stackfr] - dli.dli_saddr));
}
snprintf(msg, sizeof(msg), "%s:%u %s()%s",
lastslash ? lastslash + 1 : file, line,
S_OR(func, "???"),
address_str);
break; /* out of section iteration */
}
}
if (bfdobj) {
bfd_close(bfdobj);
ast_std_free(syms);
syms = NULL;
}
/* Default output, if we cannot find the information within BFD */
if (!found) {
if (dli.dli_saddr == NULL) {
address_str[0] = '\0';
} else {
snprintf(address_str, sizeof(address_str), " (%p+%lX)",
dli.dli_saddr,
(unsigned long) (addresses[stackfr] - dli.dli_saddr));
}
snprintf(msg, sizeof(msg), "%s %s()%s",
lastslash ? lastslash + 1 : dli.dli_fname,
S_OR(dli.dli_sname, "<unknown>"),
address_str);
}
if (!ast_strlen_zero(msg)) {
char **tmp;
eachlen[stackfr] = strlen(msg) + 1;
if (!(tmp = ast_std_realloc(strings, strings_size + eachlen[stackfr]))) {
ast_std_free(strings);
strings = NULL;
break; /* out of stack frame iteration */
}
strings = tmp;
strings[stackfr] = (char *) strings + strings_size;
strcpy(strings[stackfr], msg);/* Safe since we just allocated the room. */
strings_size += eachlen[stackfr];
}
}
if (strings) {
/* Recalculate the offset pointers because of the reallocs. */
strings[0] = (char *) strings + num_frames * sizeof(*strings);
for (stackfr = 1; stackfr < num_frames; stackfr++) {
strings[stackfr] = strings[stackfr - 1] + eachlen[stackfr - 1];
}
}
ast_std_free(eachlen);
#else /* !defined(BETTER_BACKTRACES) */
strings = backtrace_symbols(addresses, num_frames);
#endif /* defined(BETTER_BACKTRACES) */
return strings;
}
#endif /* HAVE_BKTR */
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