--core-file ; To get a core on SIGSEGV when using Linuxthreads (ce40c2fd) · Commits · Software / OSDI20 Artifacts / mariadb

Docs/manual.texi

+18 −3

Original line number	Diff line number	Diff line
		@@ -5896,9 +5896,9 @@ of function} warnings. These may be ignored.
		@node Linux, Alpha-DEC-Unix, SunOS, Source install system issues
		@subsection Linux notes (all Linux versions)

		@strong{MySQL} uses LinuxThreads on Linux. If you are using an old Linux
		version that doesn't have @code{glibc2}, you must install LinuxThreads before
		trying to compile
		@strong{MySQL} uses LinuxThreads on Linux. If you are using an old
		Linux version that doesn't have @code{glibc2}, you must install
		LinuxThreads before trying to compile
		@strong{MySQL}. @uref{http://www.mysql.com/Downloads/Linux}

		Note that @code{glibc} versions before and including 2.1.1 has a fatal
		@@ -5969,6 +5969,11 @@ If you see a dead @code{mysqld} daemon process with @code{ps}, this usually
		means that you have found a bug in @strong{MySQL} or you have got a corrupted
		table. @xref{Crashing}.

		If you want to get a core dump on Linux if mysqld dies with a SIGSEGV
		signal, you can start mysqld with the @code{--core-file} option. Note
		that you also probably need to raise the @code{core file size} with
		@code{ulimit}!

		If you are using LinuxThreads and @code{mysqladmin shutdown} doesn't work,
		you must upgrade to LinuxThreads 0.7.1 or newer.

		@@ -6165,6 +6170,10 @@ until you have installed @code{glibc} 2.0.7-19 from source!

		You can check which version of @code{glibc} you have with @code{rpm -q glibc}.

		Another reason for the above error is if you try to use more threads
		than your Linux kernel is configured for. In this case you should rise
		the limits in @file{include/linux/tasks.h} and recompile your kernel!

		@node Linux-SPARC, Linux-Alpha, Linux-RedHat51, Linux
		@subsubsection Linux-SPARC notes

		@@ -35686,6 +35695,9 @@ though, so 3.23 is not released as a stable version yet.
		@appendixsubsec Changes in release 3.23.23
		@itemize @bullet
		@item
		Added option @code{--core-file} to @code{mysqld} to get a core file on
		Linux if mysqld dies on the SIGSEGV signal
		@item
		@strong{MySQL} client 'mysql' now starts with option --no-named-commands
		(-g) by default. This option can be disabled with --enable-named-commands
		(-G). This may cause incompatibility problems in some cases, for example
		@@ -40324,6 +40336,9 @@ old threads. You can avoid this problem by starting @code{mysqld} with
		@code{-O thread_cache_size= 'max_connections +1'}. In most cases just
		using @code{-O thread_cache_size= 5'} will help a lot!

		If you want to get a core dump on Linux if mysqld dies with a SIGSEGV signal,
		you can start mysqld with the @code{--core-file} option.

		If you are using gdb 4.17.x or above on Linux, you should install a
		@file{.gdb} file, with the following information, in your current
		directory:

sql/mysql_priv.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -127,7 +127,7 @@ void sql_element_free(void *ptr);
		#define TEST_NO_THREADS 32 /* For debugging under Linux */
		#define TEST_READCHECK 64 /* Force use of readcheck */
		#define TEST_NO_EXTRA 128
		#define TEST_KILL_ON_DEBUG 256 /* Kill server */
		#define TEST_CORE_ON_SIGNAL 256 /* Give core if signal */

		/* options for select set by the yacc parser */
		#define SELECT_DISTINCT 1

sql/mysqld.cc

+37 −6

Original line number	Diff line number	Diff line
		@@ -1003,6 +1003,20 @@ static void init_signals(void)
		}
		#else

		#ifdef HAVE_LINUXTHREADS

		/* Produce a core for the thread */

		static sig_handler write_core(int sig)
		{
		fprintf(stderr,"Got signal %s in thread %d\n",sys_siglist[sig],getpid());
		signal(sig, SIG_DFL);
		if (fork() != 0) exit(1); // Abort main program
		// Core will be written at exit
		}
		#endif


		static void init_signals(void)
		{
		sigset_t set;
		@@ -1012,6 +1026,16 @@ static void init_signals(void)

		sigset(THR_KILL_SIGNAL,end_thread_signal);
		sigset(THR_SERVER_ALARM,print_signal_warning); // Should never be called!
		#ifdef HAVE_LINUXTHREADS
		if (test_flags & TEST_CORE_ON_SIGNAL)
		{
		struct sigaction sa; sa.sa_flags = 0;
		sigemptyset(&sa.sa_mask);
		sigprocmask(SIG_SETMASK,&sa.sa_mask,NULL);
		sa.sa_handler=write_core;
		sigaction(SIGSEGV, &sa, NULL);
		}
		#endif
		(void) sigemptyset(&set);
		#ifdef THREAD_SPECIFIC_SIGPIPE
		sigset(SIGPIPE,abort_thread);
		@@ -2134,7 +2158,7 @@ enum options {OPT_ISAM_LOG=256,OPT_SKIP_NEW,OPT_SKIP_GRANT,
		OPT_MASTER_PORT, OPT_MASTER_INFO_FILE, OPT_MASTER_CONNECT_RETRY,
		OPT_SQL_BIN_UPDATE_SAME, OPT_REPLICATE_DO_DB,
		OPT_REPLICATE_IGNORE_DB, OPT_LOG_SLAVE_UPDATES,
		OPT_BINLOG_DO_DB, OPT_BINLOG_IGNORE_DB};
		OPT_BINLOG_DO_DB, OPT_BINLOG_IGNORE_DB, OPT_WANT_CORE};

		static struct option long_options[] =
		{
		@@ -2156,6 +2180,7 @@ static struct option long_options[] =
		#ifdef __WIN__
		{"console", no_argument, 0, OPT_CONSOLE},
		#endif
		{"core-file", no_argument, 0, OPT_WANT_CORE},
		{"chroot", required_argument,0, 'r'},
		{"character-sets-dir",required_argument,0, OPT_CHARSETS_DIR},
		{"datadir", required_argument, 0, 'h'},
		@@ -2189,7 +2214,9 @@ static struct option long_options[] =
		{"master-info-file", required_argument, 0, (int) OPT_MASTER_INFO_FILE},
		{"new", no_argument, 0, 'n'},
		{"old-protocol", no_argument, 0, 'o'},
		#ifndef DBUG_OFF
		{"one-thread", no_argument, 0, OPT_ONE_THREAD},
		#endif
		{"pid-file", required_argument, 0, (int) OPT_PID_FILE},
		{"port", required_argument, 0, 'P'},
		{"replicate-do-db", required_argument, 0, OPT_REPLICATE_DO_DB},
		@@ -2432,6 +2459,7 @@ static void usage(void)
		--character-sets-dir=...\n\
		Directory where character sets are\n\
		--chroot=path Chroot mysqld daemon during startup\n\
		--core-file Write core on errors\n\
		-h, --datadir=path Path to the database root");
		#ifndef DBUG_OFF
		printf("\
		@@ -2465,9 +2493,11 @@ static void usage(void)
		--pid-file=path Pid file used by safe_mysqld\n\
		-P, --port=... Port number to use for connection\n\
		-n, --new Use very new possible 'unsafe' functions\n\
		-o, --old-protocol Use the old (3.20) protocol\n\
		-o, --old-protocol Use the old (3.20) protocol\n");
		#ifndef DBUG_OFF
		puts("\
		--one-thread Only use one thread (for debugging under Linux)\n");
		/* We have to break the string here because of VC++ limits */
		#endif
		puts("\
		-O, --set-variable var=option\n\
		Give a variable an value. --help lists variables\n\
		@@ -2729,8 +2759,6 @@ static void get_options(int argc,char **argv)
		binlog_do_db.push_back(db);
		break;
		}


		case (int) OPT_SQL_BIN_UPDATE_SAME:
		opt_sql_bin_update = 1;
		break;
		@@ -2785,6 +2813,9 @@ static void get_options(int argc,char **argv)
		case (int) OPT_ONE_THREAD:
		test_flags \|= TEST_NO_THREADS;
		break;
		case (int) OPT_WANT_CORE:
		test_flags \|= TEST_CORE_ON_SIGNAL;
		break;
		case (int) OPT_BIND_ADDRESS:
		if (optarg && isdigit(optarg[0]))
		{