1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
|
/* Copyright (c) 2011, 2012, Oracle and/or its affiliates.
Copyright (c) 2011, 2014, SkySQL Ab.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
#include "mariadb.h"
#include <signal.h>
//#include "sys_vars.h"
#include <keycache.h>
#include "mysqld.h"
#include "sql_class.h"
#include "my_stacktrace.h"
#ifdef __WIN__
#include <crtdbg.h>
#define SIGNAL_FMT "exception 0x%x"
#else
#define SIGNAL_FMT "signal %d"
#endif
#ifndef PATH_MAX
#define PATH_MAX 4096
#endif
/*
We are handling signals/exceptions in this file.
Any global variables we read should be 'volatile sig_atomic_t'
to guarantee that we read some consistent value.
*/
static volatile sig_atomic_t segfaulted= 0;
extern ulong max_used_connections;
extern volatile sig_atomic_t calling_initgroups;
extern const char *optimizer_switch_names[];
static inline void output_core_info()
{
/* proc is optional on some BSDs so it can't hurt to look */
#ifdef HAVE_READLINK
char buff[PATH_MAX];
ssize_t len;
int fd;
if ((len= readlink("/proc/self/cwd", buff, sizeof(buff)-1)) >= 0)
{
buff[len]= 0;
my_safe_printf_stderr("Writing a core file...\nWorking directory at %.*s\n",
(int) len, buff);
}
#ifdef __FreeBSD__
if ((fd= my_open("/proc/curproc/rlimit", O_RDONLY, MYF(0))) >= 0)
#else
if ((fd= my_open("/proc/self/limits", O_RDONLY, MYF(0))) >= 0)
#endif
{
my_safe_printf_stderr("Resource Limits:\n");
while ((len= my_read(fd, (uchar*)buff, sizeof(buff), MYF(0))) > 0)
{
my_write_stderr(buff, len);
}
my_close(fd, MYF(0));
}
#ifdef __linux__
if ((fd= my_open("/proc/sys/kernel/core_pattern", O_RDONLY, MYF(0))) >= 0)
{
len= my_read(fd, (uchar*)buff, sizeof(buff), MYF(0));
my_safe_printf_stderr("Core pattern: %.*s\n", (int) len, buff);
my_close(fd, MYF(0));
}
#endif
#else
char buff[80];
my_getwd(buff, sizeof(buff), 0);
my_safe_printf_stderr("Writing a core file at %s\n", buff);
fflush(stderr);
#endif
}
/**
* Handler for fatal signals on POSIX, exception handler on Windows.
*
* Fatal events (seg.fault, bus error etc.) will trigger
* this signal handler. The handler will try to dump relevant
* debugging information to stderr and dump a core image.
*
* POSIX : Signal handlers should, if possible, only use a set of 'safe' system
* calls and library functions. A list of safe calls in POSIX systems
* are available at:
* http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_04.html
*
* @param sig Signal number /Exception code
*/
extern "C" sig_handler handle_fatal_signal(int sig)
{
time_t curr_time;
struct tm tm;
#ifdef HAVE_STACKTRACE
THD *thd;
/*
This flag remembers if the query pointer was found invalid.
We will try and print the query at the end of the signal handler, in case
we're wrong.
*/
bool print_invalid_query_pointer= false;
#endif
if (segfaulted)
{
my_safe_printf_stderr("Fatal " SIGNAL_FMT " while backtracing\n", sig);
goto end;
}
segfaulted = 1;
curr_time= my_time(0);
localtime_r(&curr_time, &tm);
my_safe_printf_stderr("%02d%02d%02d %2d:%02d:%02d ",
tm.tm_year % 100, tm.tm_mon+1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec);
if (opt_expect_abort
#ifdef _WIN32
&& sig == (int)EXCEPTION_BREAKPOINT /* __debugbreak in my_sigabrt_hander() */
#else
&& sig == SIGABRT
#endif
)
{
fprintf(stderr,"[Note] mysqld did an expected abort\n");
goto end;
}
my_safe_printf_stderr("[ERROR] mysqld got " SIGNAL_FMT " ;\n",sig);
my_safe_printf_stderr("%s",
"This could be because you hit a bug. It is also possible that this binary\n"
"or one of the libraries it was linked against is corrupt, improperly built,\n"
"or misconfigured. This error can also be caused by malfunctioning hardware.\n\n");
my_safe_printf_stderr("%s",
"To report this bug, see https://mariadb.com/kb/en/reporting-bugs\n\n");
my_safe_printf_stderr("%s",
"We will try our best to scrape up some info that will hopefully help\n"
"diagnose the problem, but since we have already crashed, \n"
"something is definitely wrong and this may fail.\n\n");
set_server_version(server_version, sizeof(server_version));
my_safe_printf_stderr("Server version: %s\n", server_version);
if (dflt_key_cache)
my_safe_printf_stderr("key_buffer_size=%lu\n",
(ulong) dflt_key_cache->key_cache_mem_size);
my_safe_printf_stderr("read_buffer_size=%ld\n",
(long) global_system_variables.read_buff_size);
my_safe_printf_stderr("max_used_connections=%lu\n",
(ulong) max_used_connections);
if (thread_scheduler)
my_safe_printf_stderr("max_threads=%u\n",
(uint) thread_scheduler->max_threads +
(uint) extra_max_connections);
my_safe_printf_stderr("thread_count=%u\n", (uint) thread_count);
if (dflt_key_cache && thread_scheduler)
{
my_safe_printf_stderr("It is possible that mysqld could use up to \n"
"key_buffer_size + "
"(read_buffer_size + sort_buffer_size)*max_threads = "
"%lu K bytes of memory\n",
(ulong)
(dflt_key_cache->key_cache_mem_size +
(global_system_variables.read_buff_size +
global_system_variables.sortbuff_size) *
(thread_scheduler->max_threads + extra_max_connections) +
(max_connections + extra_max_connections) *
sizeof(THD)) / 1024);
my_safe_printf_stderr("%s",
"Hope that's ok; if not, decrease some variables in "
"the equation.\n\n");
}
#ifdef HAVE_STACKTRACE
thd= current_thd;
if (opt_stack_trace)
{
my_safe_printf_stderr("Thread pointer: %p\n", thd);
my_safe_printf_stderr("%s",
"Attempting backtrace. You can use the following "
"information to find out\n"
"where mysqld died. If you see no messages after this, something went\n"
"terribly wrong...\n");
my_print_stacktrace(thd ? (uchar*) thd->thread_stack : NULL,
(ulong)my_thread_stack_size, 0);
}
if (thd)
{
const char *kreason= "UNKNOWN";
switch (thd->killed) {
case NOT_KILLED:
case KILL_HARD_BIT:
kreason= "NOT_KILLED";
break;
case KILL_BAD_DATA:
case KILL_BAD_DATA_HARD:
kreason= "KILL_BAD_DATA";
break;
case KILL_CONNECTION:
case KILL_CONNECTION_HARD:
kreason= "KILL_CONNECTION";
break;
case KILL_QUERY:
case KILL_QUERY_HARD:
kreason= "KILL_QUERY";
break;
case KILL_TIMEOUT:
case KILL_TIMEOUT_HARD:
kreason= "KILL_TIMEOUT";
break;
case KILL_SYSTEM_THREAD:
case KILL_SYSTEM_THREAD_HARD:
kreason= "KILL_SYSTEM_THREAD";
break;
case KILL_SERVER:
case KILL_SERVER_HARD:
kreason= "KILL_SERVER";
break;
case ABORT_QUERY:
case ABORT_QUERY_HARD:
kreason= "ABORT_QUERY";
break;
case KILL_SLAVE_SAME_ID:
kreason= "KILL_SLAVE_SAME_ID";
break;
case KILL_WAIT_TIMEOUT:
case KILL_WAIT_TIMEOUT_HARD:
kreason= "KILL_WAIT_TIMEOUT";
break;
}
my_safe_printf_stderr("%s", "\n"
"Trying to get some variables.\n"
"Some pointers may be invalid and cause the dump to abort.\n");
my_safe_printf_stderr("Query (%p): ", thd->query());
if (my_safe_print_str(thd->query(), MY_MIN(65536U, thd->query_length())))
{
// Query was found invalid. We will try to print it at the end.
print_invalid_query_pointer= true;
}
my_safe_printf_stderr("\nConnection ID (thread ID): %lu\n",
(ulong) thd->thread_id);
my_safe_printf_stderr("Status: %s\n\n", kreason);
my_safe_printf_stderr("%s", "Optimizer switch: ");
ulonglong optsw= thd->variables.optimizer_switch;
for (uint i= 0; optimizer_switch_names[i+1]; i++, optsw >>= 1)
{
if (i)
my_safe_printf_stderr("%s", ",");
my_safe_printf_stderr("%s=%s",
optimizer_switch_names[i], optsw & 1 ? "on" : "off");
}
my_safe_printf_stderr("%s", "\n\n");
}
my_safe_printf_stderr("%s",
"The manual page at "
"https://mariadb.com/kb/en/how-to-produce-a-full-stack-trace-for-mysqld/ contains\n"
"information that should help you find out what is causing the crash.\n");
#endif /* HAVE_STACKTRACE */
#ifdef HAVE_INITGROUPS
if (calling_initgroups)
{
my_safe_printf_stderr("%s", "\n"
"This crash occurred while the server was calling initgroups(). This is\n"
"often due to the use of a mysqld that is statically linked against \n"
"glibc and configured to use LDAP in /etc/nsswitch.conf.\n"
"You will need to either upgrade to a version of glibc that does not\n"
"have this problem (2.3.4 or later when used with nscd),\n"
"disable LDAP in your nsswitch.conf, or use a "
"mysqld that is not statically linked.\n");
}
#endif
if (locked_in_memory)
{
my_safe_printf_stderr("%s", "\n"
"The \"--memlock\" argument, which was enabled, "
"uses system calls that are\n"
"unreliable and unstable on some operating systems and "
"operating-system versions (notably, some versions of Linux).\n"
"This crash could be due to use of those buggy OS calls.\n"
"You should consider whether you really need the "
"\"--memlock\" parameter and/or consult the OS distributer about "
"\"mlockall\" bugs.\n");
}
#ifdef HAVE_STACKTRACE
if (print_invalid_query_pointer)
{
my_safe_printf_stderr(
"\nWe think the query pointer is invalid, but we will try "
"to print it anyway. \n"
"Query: ");
my_write_stderr(thd->query(), MY_MIN(65536U, thd->query_length()));
my_safe_printf_stderr("\n\n");
}
#endif
output_core_info();
#ifdef HAVE_WRITE_CORE
if (test_flags & TEST_CORE_ON_SIGNAL)
{
my_write_core(sig);
}
#endif
end:
#ifndef __WIN__
/*
Quit, without running destructors (etc.)
Use a signal, because the parent (systemd) can check that with WIFSIGNALED
On Windows, do not terminate, but pass control to exception filter.
*/
signal(sig, SIG_DFL);
kill(getpid(), sig);
#else
return;
#endif
}
|