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)
110 if (fault_state.disabled) {
113 #if !defined(HAVE_DISABLE_FAULT_HANDLING)
115 CatchSignal(SIGSEGV, sig_fault);
118 CatchSignal(SIGBUS, sig_fault);
121 CatchSignal(SIGABRT, sig_fault);
126 _PUBLIC_ const char *panic_action = NULL;
129 default smb_panic() implementation
131 static void smb_panic_default(const char *why) _NORETURN_;
132 static void smb_panic_default(const char *why)
134 DBG_ERR("PANIC (pid %llu): %s\n",
135 (unsigned long long)getpid(), why);
138 #if defined(HAVE_PRCTL) && defined(PR_SET_PTRACER)
140 * Make sure all children can attach a debugger.
142 prctl(PR_SET_PTRACER, getpid(), 0, 0, 0);
145 if (panic_action && *panic_action) {
147 if (strlcpy(cmdstring, panic_action, sizeof(cmdstring)) < sizeof(cmdstring)) {
150 snprintf(pidstr, sizeof(pidstr), "%d", (int) getpid());
151 all_string_sub(cmdstring, "%d", pidstr, sizeof(cmdstring));
152 DEBUG(0, ("smb_panic(): calling panic action [%s]\n", cmdstring));
153 result = system(cmdstring);
156 DEBUG(0, ("smb_panic(): fork failed in panic action: %s\n",
159 DEBUG(0, ("smb_panic(): action returned status %d\n",
160 WEXITSTATUS(result)));
165 CatchSignal(SIGABRT, SIG_DFL);
172 Something really nasty happened - panic !
174 _PUBLIC_ void smb_panic(const char *why)
176 if (fault_state.panic_handler) {
177 fault_state.panic_handler(why);
180 smb_panic_default(why);
183 /*******************************************************************
184 Print a backtrace of the stack to the debug log. This function
185 DELIBERATELY LEAKS MEMORY. The expectation is that you should
186 exit shortly after calling it.
187 ********************************************************************/
189 /* Buffer size to use when printing backtraces */
190 #define BACKTRACE_STACK_SIZE 64
193 #ifdef HAVE_LIBUNWIND_H
194 #include <libunwind.h>
197 #ifdef HAVE_EXECINFO_H
198 #include <execinfo.h>
201 void log_stack_trace(void)
203 #ifdef HAVE_LIBUNWIND
204 /* Try to use libunwind before any other technique since on ia64
205 * libunwind correctly walks the stack in more circumstances than
213 unw_word_t ip, sp, off;
215 procname[sizeof(procname) - 1] = '\0';
217 if (unw_getcontext(&uc) != 0) {
218 goto libunwind_failed;
221 if (unw_init_local(&cursor, &uc) != 0) {
222 goto libunwind_failed;
225 DEBUG(0, ("BACKTRACE:\n"));
229 unw_get_reg(&cursor, UNW_REG_IP, &ip);
230 unw_get_reg(&cursor, UNW_REG_SP, &sp);
232 switch (unw_get_proc_name(&cursor,
233 procname, sizeof(procname) - 1, &off) ) {
237 /* Name truncated. */
238 DEBUGADD(0, (" #%u %s + %#llx [ip=%#llx] [sp=%#llx]\n",
239 i, procname, (long long)off,
240 (long long)ip, (long long) sp));
243 /* case -UNW_ENOINFO: */
244 /* case -UNW_EUNSPEC: */
245 /* No symbol name found. */
246 DEBUGADD(0, (" #%u %s [ip=%#llx] [sp=%#llx]\n",
247 i, "<unknown symbol>",
248 (long long)ip, (long long) sp));
251 } while (unw_step(&cursor) > 0);
256 DEBUG(0, ("unable to produce a stack trace with libunwind\n"));
258 #elif defined(HAVE_BACKTRACE_SYMBOLS)
259 void *backtrace_stack[BACKTRACE_STACK_SIZE];
260 size_t backtrace_size;
261 char **backtrace_strings;
263 /* get the backtrace (stack frames) */
264 backtrace_size = backtrace(backtrace_stack,BACKTRACE_STACK_SIZE);
265 backtrace_strings = backtrace_symbols(backtrace_stack, backtrace_size);
267 DEBUG(0, ("BACKTRACE: %lu stack frames:\n",
268 (unsigned long)backtrace_size));
270 if (backtrace_strings) {
273 for (i = 0; i < backtrace_size; i++)
274 DEBUGADD(0, (" #%u %s\n", i, backtrace_strings[i]));
276 /* Leak the backtrace_strings, rather than risk what free() might do */
280 DEBUG(0, ("unable to produce a stack trace on this platform\n"));