source: trunk/server/source3/lib/fault.c@ 421

Last change on this file since 421 was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial import
File size: 8.0 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 Critical Fault handling
4 Copyright (C) Andrew Tridgell 1992-1998
5 Copyright (C) Tim Prouty 2009
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "includes.h"
22
23#ifdef HAVE_SYS_SYSCTL_H
24#include <sys/sysctl.h>
25#endif
26
27
28#ifdef HAVE_SYS_PRCTL_H
29#include <sys/prctl.h>
30#endif
31
32static void (*cont_fn)(void *);
33static char *corepath;
34
35/*******************************************************************
36report a fault
37********************************************************************/
38static void fault_report(int sig)
39{
40 static int counter;
41
42 if (counter) _exit(1);
43
44 counter++;
45
46 DEBUGSEP(0);
47 DEBUG(0,("INTERNAL ERROR: Signal %d in pid %d (%s)",sig,(int)sys_getpid(),samba_version_string()));
48 DEBUG(0,("\nPlease read the Trouble-Shooting section of the Samba3-HOWTO\n"));
49 DEBUG(0,("\nFrom: http://www.samba.org/samba/docs/Samba3-HOWTO.pdf\n"));
50 DEBUGSEP(0);
51
52 smb_panic("internal error");
53
54 if (cont_fn) {
55 cont_fn(NULL);
56#ifdef SIGSEGV
57 CatchSignal(SIGSEGV,SIGNAL_CAST SIG_DFL);
58#endif
59#ifdef SIGBUS
60 CatchSignal(SIGBUS,SIGNAL_CAST SIG_DFL);
61#endif
62#ifdef SIGABRT
63 CatchSignal(SIGABRT,SIGNAL_CAST SIG_DFL);
64#endif
65 return; /* this should cause a core dump */
66 }
67 exit(1);
68}
69
70/****************************************************************************
71catch serious errors
72****************************************************************************/
73static void sig_fault(int sig)
74{
75 fault_report(sig);
76}
77
78/*******************************************************************
79setup our fault handlers
80********************************************************************/
81void fault_setup(void (*fn)(void *))
82{
83 cont_fn = fn;
84
85#ifdef SIGSEGV
86 CatchSignal(SIGSEGV,SIGNAL_CAST sig_fault);
87#endif
88#ifdef SIGBUS
89 CatchSignal(SIGBUS,SIGNAL_CAST sig_fault);
90#endif
91#ifdef SIGABRT
92 CatchSignal(SIGABRT,SIGNAL_CAST sig_fault);
93#endif
94}
95
96/**
97 * Build up the default corepath as "<logbase>/cores/<progname>"
98 */
99static char *get_default_corepath(const char *logbase, const char *progname)
100{
101 char *tmp_corepath;
102
103 /* Setup core dir in logbase. */
104 tmp_corepath = talloc_asprintf(NULL, "%s/cores", logbase);
105 if (!tmp_corepath)
106 return NULL;
107
108 if ((mkdir(tmp_corepath, 0700) == -1) && errno != EEXIST)
109 goto err_out;
110
111 if (chmod(tmp_corepath, 0700) == -1)
112 goto err_out;
113
114 talloc_free(tmp_corepath);
115
116 /* Setup progname-specific core subdir */
117 tmp_corepath = talloc_asprintf(NULL, "%s/cores/%s", logbase, progname);
118 if (!tmp_corepath)
119 return NULL;
120
121 if (mkdir(tmp_corepath, 0700) == -1 && errno != EEXIST)
122 goto err_out;
123
124 if (chown(tmp_corepath, getuid(), getgid()) == -1)
125 goto err_out;
126
127 if (chmod(tmp_corepath, 0700) == -1)
128 goto err_out;
129
130 return tmp_corepath;
131
132 err_out:
133 talloc_free(tmp_corepath);
134 return NULL;
135}
136
137/**
138 * Get the FreeBSD corepath.
139 *
140 * On FreeBSD the current working directory is ignored when creating a core
141 * file. Instead the core directory is controlled via sysctl. This consults
142 * the value of "kern.corefile" so the correct corepath can be printed out
143 * before dump_core() calls abort.
144 */
145#if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
146static char *get_freebsd_corepath(void)
147{
148 char *tmp_corepath = NULL;
149 char *end = NULL;
150 size_t len = 128;
151 int ret;
152
153 /* Loop with increasing sizes so we don't allocate too much. */
154 do {
155 if (len > 1024) {
156 goto err_out;
157 }
158
159 tmp_corepath = (char *)talloc_realloc(NULL, tmp_corepath,
160 char, len);
161 if (!tmp_corepath) {
162 return NULL;
163 }
164
165 ret = sysctlbyname("kern.corefile", tmp_corepath, &len, NULL,
166 0);
167 if (ret == -1) {
168 if (errno != ENOMEM) {
169 DEBUG(0, ("sysctlbyname failed getting "
170 "kern.corefile %s\n",
171 strerror(errno)));
172 goto err_out;
173 }
174
175 /* Not a large enough array, try a bigger one. */
176 len = len << 1;
177 }
178 } while (ret == -1);
179
180 /* Strip off the common filename expansion */
181 if ((end = strrchr_m(tmp_corepath, '/'))) {
182 *end = '\0';
183 }
184
185 return tmp_corepath;
186
187 err_out:
188 if (tmp_corepath) {
189 talloc_free(tmp_corepath);
190 }
191 return NULL;
192}
193#endif
194
195/**
196 * Try getting system-specific corepath if one exists.
197 *
198 * If the system doesn't define a corepath, then the default is used.
199 */
200static char *get_corepath(const char *logbase, const char *progname)
201{
202#if (defined(FREEBSD) && defined(HAVE_SYSCTLBYNAME))
203
204 /* @todo: Add support for the linux corepath. */
205
206 char *tmp_corepath = NULL;
207 tmp_corepath = get_freebsd_corepath();
208
209 /* If this has been set correctly, we're done. */
210 if (tmp_corepath) {
211 return tmp_corepath;
212 }
213#endif
214
215 /* Fall back to the default. */
216 return get_default_corepath(logbase, progname);
217}
218
219/*******************************************************************
220make all the preparations to safely dump a core file
221********************************************************************/
222
223void dump_core_setup(const char *progname)
224{
225 char *logbase = NULL;
226 char *end = NULL;
227
228 if (lp_logfile() && *lp_logfile()) {
229 if (asprintf(&logbase, "%s", lp_logfile()) < 0) {
230 return;
231 }
232 if ((end = strrchr_m(logbase, '/'))) {
233 *end = '\0';
234 }
235 } else {
236 /* We will end up here if the log file is given on the command
237 * line by the -l option but the "log file" option is not set
238 * in smb.conf.
239 */
240 if (asprintf(&logbase, "%s", get_dyn_LOGFILEBASE()) < 0) {
241 return;
242 }
243 }
244
245 SMB_ASSERT(progname != NULL);
246
247 corepath = get_corepath(logbase, progname);
248 if (!corepath) {
249 DEBUG(0, ("Unable to setup corepath for %s: %s\n", progname,
250 strerror(errno)));
251 goto out;
252 }
253
254
255#ifdef HAVE_GETRLIMIT
256#ifdef RLIMIT_CORE
257 {
258 struct rlimit rlp;
259 getrlimit(RLIMIT_CORE, &rlp);
260 rlp.rlim_cur = MAX(16*1024*1024,rlp.rlim_cur);
261 setrlimit(RLIMIT_CORE, &rlp);
262 getrlimit(RLIMIT_CORE, &rlp);
263 DEBUG(3,("Maximum core file size limits now %d(soft) %d(hard)\n",
264 (int)rlp.rlim_cur,(int)rlp.rlim_max));
265 }
266#endif
267#endif
268
269#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
270 /* On Linux we lose the ability to dump core when we change our user
271 * ID. We know how to dump core safely, so let's make sure we have our
272 * dumpable flag set.
273 */
274 prctl(PR_SET_DUMPABLE, 1);
275#endif
276
277 /* FIXME: if we have a core-plus-pid facility, configurably set
278 * this up here.
279 */
280 out:
281 SAFE_FREE(logbase);
282}
283
284 void dump_core(void)
285{
286 static bool called;
287
288 if (called) {
289 DEBUG(0, ("dump_core() called recursive\n"));
290 exit(1);
291 }
292 called = true;
293
294 /* Note that even if core dumping has been disabled, we still set up
295 * the core path. This is to handle the case where core dumping is
296 * turned on in smb.conf and the relevant daemon is not restarted.
297 */
298 if (!lp_enable_core_files()) {
299 DEBUG(0, ("Exiting on internal error (core file administratively disabled)\n"));
300 exit(1);
301 }
302
303#if DUMP_CORE
304 /* If we're running as non root we might not be able to dump the core
305 * file to the corepath. There must not be an unbecome_root() before
306 * we call abort(). */
307 if (geteuid() != 0) {
308 become_root();
309 }
310
311 if (corepath == NULL) {
312 DEBUG(0, ("Can not dump core: corepath not set up\n"));
313 exit(1);
314 }
315
316 if (*corepath != '\0') {
317 /* The chdir might fail if we dump core before we finish
318 * processing the config file.
319 */
320 if (chdir(corepath) != 0) {
321 DEBUG(0, ("unable to change to %s\n", corepath));
322 DEBUGADD(0, ("refusing to dump core\n"));
323 exit(1);
324 }
325
326 DEBUG(0,("dumping core in %s\n", corepath));
327 }
328
329 umask(~(0700));
330 dbgflush();
331
332 /* Ensure we don't have a signal handler for abort. */
333#ifdef SIGABRT
334 CatchSignal(SIGABRT,SIGNAL_CAST SIG_DFL);
335#endif
336
337 abort();
338
339#else /* DUMP_CORE */
340 exit(1);
341#endif /* DUMP_CORE */
342}
343
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