2 Unix SMB/CIFS implementation.
3 Critical Fault handling
4 Copyright (C) Andrew Tridgell 1992-1998
5 Copyright (C) Tim Prouty 2009
6 Copyright (C) James Peach 2006
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include "system/filesys.h"
24 #include "system/wait.h"
27 #ifdef HAVE_SYS_SYSCTL_H
28 #include <sys/sysctl.h>
32 #ifdef HAVE_SYS_PRCTL_H
33 #include <sys/prctl.h>
37 #include "lib/util/signal.h" /* Avoid /usr/include/signal.h */
38 #include "substitute.h"
43 smb_panic_handler_t panic_handler;
47 /*******************************************************************
48 setup variables used for fault handling
49 ********************************************************************/
50 void fault_configure(smb_panic_handler_t panic_handler)
52 fault_state.panic_handler = panic_handler;
57 disable setting up fault handlers
58 This is used for the bind9 dlz module, as we
59 don't want a Samba module in bind9 to override the bind
62 _PUBLIC_ void fault_setup_disable(void)
64 fault_state.disabled = true;
68 /*******************************************************************
70 ********************************************************************/
71 static void fault_report(int sig)
75 if (counter) _exit(1);
80 DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)getpid(),SAMBA_VERSION_STRING));
81 DEBUG(0,("\nPlease read the Trouble-Shooting section of the Samba HOWTO\n"));
84 smb_panic("internal error");
86 /* smb_panic() never returns, so this is really redundant */
90 /****************************************************************************
92 ****************************************************************************/
93 static void sig_fault(int sig)
98 /*******************************************************************
99 setup our fault handlers
100 ********************************************************************/
101 void fault_setup(void)
103 if (fault_state.disabled) {
106 #if !defined(HAVE_DISABLE_FAULT_HANDLING)
108 CatchSignal(SIGSEGV, sig_fault);
111 CatchSignal(SIGBUS, sig_fault);
114 CatchSignal(SIGABRT, sig_fault);
119 _PUBLIC_ const char *panic_action = NULL;
122 default smb_panic() implementation
124 static void smb_panic_default(const char *why) _NORETURN_;
125 static void smb_panic_default(const char *why)
127 DBG_ERR("PANIC (pid %llu): %s\n",
128 (unsigned long long)getpid(), why);
131 #if defined(HAVE_PRCTL) && defined(PR_SET_PTRACER)
133 * Make sure all children can attach a debugger.
135 prctl(PR_SET_PTRACER, getpid(), 0, 0, 0);
138 if (panic_action && *panic_action) {
140 if (strlcpy(cmdstring, panic_action, sizeof(cmdstring)) < sizeof(cmdstring)) {
143 snprintf(pidstr, sizeof(pidstr), "%d", (int) getpid());
144 all_string_sub(cmdstring, "%d", pidstr, sizeof(cmdstring));
145 DEBUG(0, ("smb_panic(): calling panic action [%s]\n", cmdstring));
146 result = system(cmdstring);
149 DEBUG(0, ("smb_panic(): fork failed in panic action: %s\n",
152 DEBUG(0, ("smb_panic(): action returned status %d\n",
153 WEXITSTATUS(result)));
158 CatchSignal(SIGABRT, SIG_DFL);
165 Something really nasty happened - panic !
167 _PUBLIC_ void smb_panic(const char *why)
169 if (fault_state.panic_handler) {
170 fault_state.panic_handler(why);
173 smb_panic_default(why);
176 /*******************************************************************
177 Print a backtrace of the stack to the debug log. This function
178 DELIBERATELY LEAKS MEMORY. The expectation is that you should
179 exit shortly after calling it.
180 ********************************************************************/
182 /* Buffer size to use when printing backtraces */
183 #define BACKTRACE_STACK_SIZE 64
186 #ifdef HAVE_LIBUNWIND_H
187 #include <libunwind.h>
190 #ifdef HAVE_EXECINFO_H
191 #include <execinfo.h>
194 void log_stack_trace(void)
196 #ifdef HAVE_LIBUNWIND
197 /* Try to use libunwind before any other technique since on ia64
198 * libunwind correctly walks the stack in more circumstances than
206 unw_word_t ip, sp, off;
208 procname[sizeof(procname) - 1] = '\0';
210 if (unw_getcontext(&uc) != 0) {
211 goto libunwind_failed;
214 if (unw_init_local(&cursor, &uc) != 0) {
215 goto libunwind_failed;
218 DEBUG(0, ("BACKTRACE:\n"));
222 unw_get_reg(&cursor, UNW_REG_IP, &ip);
223 unw_get_reg(&cursor, UNW_REG_SP, &sp);
225 switch (unw_get_proc_name(&cursor,
226 procname, sizeof(procname) - 1, &off) ) {
230 /* Name truncated. */
231 DEBUGADD(0, (" #%u %s + %#llx [ip=%#llx] [sp=%#llx]\n",
232 i, procname, (long long)off,
233 (long long)ip, (long long) sp));
236 /* case -UNW_ENOINFO: */
237 /* case -UNW_EUNSPEC: */
238 /* No symbol name found. */
239 DEBUGADD(0, (" #%u %s [ip=%#llx] [sp=%#llx]\n",
240 i, "<unknown symbol>",
241 (long long)ip, (long long) sp));
244 } while (unw_step(&cursor) > 0);
249 DEBUG(0, ("unable to produce a stack trace with libunwind\n"));
251 #elif HAVE_BACKTRACE_SYMBOLS
252 void *backtrace_stack[BACKTRACE_STACK_SIZE];
253 size_t backtrace_size;
254 char **backtrace_strings;
256 /* get the backtrace (stack frames) */
257 backtrace_size = backtrace(backtrace_stack,BACKTRACE_STACK_SIZE);
258 backtrace_strings = backtrace_symbols(backtrace_stack, backtrace_size);
260 DEBUG(0, ("BACKTRACE: %lu stack frames:\n",
261 (unsigned long)backtrace_size));
263 if (backtrace_strings) {
266 for (i = 0; i < backtrace_size; i++)
267 DEBUGADD(0, (" #%u %s\n", i, backtrace_strings[i]));
269 /* Leak the backtrace_strings, rather than risk what free() might do */
273 DEBUG(0, ("unable to produce a stack trace on this platform\n"));