summaryrefslogtreecommitdiff
path: root/sql/mysqld.cc
diff options
context:
space:
mode:
authorTor Didriksen <tor.didriksen@oracle.com>2011-11-30 15:39:29 +0100
committerTor Didriksen <tor.didriksen@oracle.com>2011-11-30 15:39:29 +0100
commit31aa2b6f3cbaae87a479a223dd8d7fa705bd8899 (patch)
tree96463acbe03a8468be26d0cc712065897cb8ac97 /sql/mysqld.cc
parentcfef24eb4f0f2f9f807e4ce7138aba8390abc7cd (diff)
downloadmariadb-git-31aa2b6f3cbaae87a479a223dd8d7fa705bd8899.tar.gz
Bug#11761576 54082: HANDLE_SEGFAULT MAKES USE OF UNSAFE FUNCTIONS
handle_segfault is the signal handler code of mysqld. however, it makes calls to potentially unsafe functions localtime_r, fprintf, fflush.
Diffstat (limited to 'sql/mysqld.cc')
-rw-r--r--sql/mysqld.cc190
1 files changed, 18 insertions, 172 deletions
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 37eb6d95ce8..73b107e4746 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -122,13 +122,6 @@ extern "C" { // Because of SCO 3.2V4.2
#include <sys/mman.h>
#endif
-#ifdef __WIN__
-#include <crtdbg.h>
-#define SIGNAL_FMT "exception 0x%x"
-#else
-#define SIGNAL_FMT "signal %d"
-#endif
-
#ifdef __NETWARE__
#define zVOLSTATE_ACTIVE 6
#define zVOLSTATE_DEACTIVE 2
@@ -269,7 +262,7 @@ inline void setup_fpu()
extern "C" int gethostname(char *name, int namelen);
#endif
-extern "C" sig_handler handle_segfault(int sig);
+extern "C" sig_handler handle_fatal_signal(int sig);
#if defined(__linux__)
#define ENABLE_TEMP_POOL 1
@@ -415,6 +408,10 @@ TYPELIB log_output_typelib= {array_elements(log_output_names)-1,"",
/* static variables */
+#ifdef HAVE_NPTL
+volatile sig_atomic_t ld_assume_kernel_is_set= 0;
+#endif
+
/* the default log output is log tables */
static bool lower_case_table_names_used= 0;
static bool max_long_data_size_used= false;
@@ -424,7 +421,7 @@ static my_bool opt_debugging= 0, opt_external_locking= 0, opt_console= 0;
static my_bool opt_short_log_format= 0;
static uint kill_cached_threads, wake_thread;
static ulong killed_threads, thread_created;
-static ulong max_used_connections;
+ ulong max_used_connections;
static ulong my_bind_addr; /**< the address we bind to */
static volatile ulong cached_thread_count= 0;
static const char *sql_mode_str= "OFF";
@@ -553,7 +550,7 @@ TYPELIB binlog_format_typelib=
ulong opt_binlog_format_id= (ulong) BINLOG_FORMAT_UNSPEC;
const char *opt_binlog_format= binlog_format_names[opt_binlog_format_id];
#ifdef HAVE_INITGROUPS
-static bool calling_initgroups= FALSE; /**< Used in SIGSEGV handler. */
+volatile sig_atomic_t calling_initgroups= 0; /**< Used in SIGSEGV handler. */
#endif
uint mysqld_port, test_flags, select_errors, dropping_tables, ha_open_options;
uint mysqld_port_timeout;
@@ -727,7 +724,7 @@ char *opt_logname, *opt_slow_logname;
/* Static variables */
-static bool kill_in_progress, segfaulted;
+static volatile sig_atomic_t kill_in_progress;
#ifdef HAVE_STACK_TRACE_ON_SEGV
static my_bool opt_do_pstack;
#endif /* HAVE_STACK_TRACE_ON_SEGV */
@@ -1616,9 +1613,9 @@ static void set_user(const char *user, struct passwd *user_info_arg)
calling_initgroups as a flag to the SIGSEGV handler that is then used to
output a specific message to help the user resolve this problem.
*/
- calling_initgroups= TRUE;
+ calling_initgroups= 1;
initgroups((char*) user, user_info_arg->pw_gid);
- calling_initgroups= FALSE;
+ calling_initgroups= 0;
#endif
if (setgid(user_info_arg->pw_gid) == -1)
{
@@ -2170,7 +2167,7 @@ LONG WINAPI my_unhandler_exception_filter(EXCEPTION_POINTERS *ex_pointers)
__try
{
my_set_exception_pointers(ex_pointers);
- handle_segfault(ex_pointers->ExceptionRecord->ExceptionCode);
+ handle_fatal_signal(ex_pointers->ExceptionRecord->ExceptionCode);
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
@@ -2481,161 +2478,6 @@ extern "C" char *my_demangle(const char *mangled_name, int *status)
#endif
-extern "C" sig_handler handle_segfault(int sig)
-{
- time_t curr_time;
- struct tm tm;
-
- /*
- Strictly speaking, one needs a mutex here
- but since we have got SIGSEGV already, things are a mess
- so not having the mutex is not as bad as possibly using a buggy
- mutex - so we keep things simple
- */
- if (segfaulted)
- {
- fprintf(stderr, "Fatal " SIGNAL_FMT " while backtracing\n", sig);
- exit(1);
- }
-
- segfaulted = 1;
-
- curr_time= my_time(0);
- localtime_r(&curr_time, &tm);
-
- fprintf(stderr,"\
-%02d%02d%02d %2d:%02d:%02d - mysqld got " SIGNAL_FMT " ;\n\
-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",
- tm.tm_year % 100, tm.tm_mon+1, tm.tm_mday,
- tm.tm_hour, tm.tm_min, tm.tm_sec,
- sig);
- fprintf(stderr, "\
-We will try our best to scrape up some info that will hopefully help diagnose\n\
-the problem, but since we have already crashed, something is definitely wrong\n\
-and this may fail.\n\n");
- fprintf(stderr, "key_buffer_size=%lu\n",
- (ulong) dflt_key_cache->key_cache_mem_size);
- fprintf(stderr, "read_buffer_size=%ld\n", (long) global_system_variables.read_buff_size);
- fprintf(stderr, "max_used_connections=%lu\n", max_used_connections);
- fprintf(stderr, "max_threads=%u\n", thread_scheduler.max_threads);
- fprintf(stderr, "threads_connected=%u\n", thread_count);
- fprintf(stderr, "It is possible that mysqld could use up to \n\
-key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = %lu K\n\
-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 +
- max_connections * sizeof(THD)) / 1024);
- fprintf(stderr, "Hope that's ok; if not, decrease some variables in the equation.\n\n");
-
-#if defined(HAVE_LINUXTHREADS)
- if (sizeof(char*) == 4 && thread_count > UNSAFE_DEFAULT_LINUX_THREADS)
- {
- fprintf(stderr, "\
-You seem to be running 32-bit Linux and have %d concurrent connections.\n\
-If you have not changed STACK_SIZE in LinuxThreads and built the binary \n\
-yourself, LinuxThreads is quite likely to steal a part of the global heap for\n\
-the thread stack. Please read http://dev.mysql.com/doc/mysql/en/linux.html\n\n",
- thread_count);
- }
-#endif /* HAVE_LINUXTHREADS */
-
-#ifdef HAVE_STACKTRACE
- THD *thd=current_thd;
-
- if (!(test_flags & TEST_NO_STACKTRACE))
- {
- fprintf(stderr, "Thread pointer: 0x%lx\n", (long) thd);
- fprintf(stderr, "Attempting backtrace. You can use the following "
- "information to find out\nwhere mysqld died. If "
- "you see no messages after this, something went\n"
- "terribly wrong...\n");
- my_print_stacktrace(thd ? (uchar*) thd->thread_stack : NULL,
- my_thread_stack_size);
- }
- if (thd)
- {
- const char *kreason= "UNKNOWN";
- switch (thd->killed) {
- case THD::NOT_KILLED:
- kreason= "NOT_KILLED";
- break;
- case THD::KILL_BAD_DATA:
- kreason= "KILL_BAD_DATA";
- break;
- case THD::KILL_CONNECTION:
- kreason= "KILL_CONNECTION";
- break;
- case THD::KILL_QUERY:
- kreason= "KILL_QUERY";
- break;
- case THD::KILLED_NO_VALUE:
- kreason= "KILLED_NO_VALUE";
- break;
- }
- fprintf(stderr, "\nTrying to get some variables.\n"
- "Some pointers may be invalid and cause the dump to abort.\n");
- fprintf(stderr, "Query (%p): ", thd->query());
- my_safe_print_str(thd->query(), min(1024, thd->query_length()));
- fprintf(stderr, "Connection ID (thread ID): %lu\n", (ulong) thd->thread_id);
- fprintf(stderr, "Status: %s\n", kreason);
- fputc('\n', stderr);
- }
- fprintf(stderr, "\
-The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains\n\
-information that should help you find out what is causing the crash.\n");
- fflush(stderr);
-#endif /* HAVE_STACKTRACE */
-
-#ifdef HAVE_INITGROUPS
- if (calling_initgroups)
- fprintf(stderr, "\n\
-This crash occured while the server was calling initgroups(). This is\n\
-often due to the use of a mysqld that is statically linked against glibc\n\
-and configured to use LDAP in /etc/nsswitch.conf. You will need to either\n\
-upgrade to a version of glibc that does not have this problem (2.3.4 or\n\
-later when used with nscd), disable LDAP in your nsswitch.conf, or use a\n\
-mysqld that is not statically linked.\n");
-#endif
-
-#ifdef HAVE_NPTL
- if (thd_lib_detected == THD_LIB_LT && !getenv("LD_ASSUME_KERNEL"))
- fprintf(stderr,"\n\
-You are running a statically-linked LinuxThreads binary on an NPTL system.\n\
-This can result in crashes on some distributions due to LT/NPTL conflicts.\n\
-You should either build a dynamically-linked binary, or force LinuxThreads\n\
-to be used with the LD_ASSUME_KERNEL environment variable. Please consult\n\
-the documentation for your distribution on how to do that.\n");
-#endif
-
- if (locked_in_memory)
- {
- fprintf(stderr, "\n\
-The \"--memlock\" argument, which was enabled, uses system calls that are\n\
-unreliable and unstable on some operating systems and operating-system\n\
-versions (notably, some versions of Linux). This crash could be due to use\n\
-of those buggy OS calls. You should consider whether you really need the\n\
-\"--memlock\" parameter and/or consult the OS distributer about \"mlockall\"\n\
-bugs.\n");
- }
-
-#ifdef HAVE_WRITE_CORE
- if (test_flags & TEST_CORE_ON_SIGNAL)
- {
- fprintf(stderr, "Writing a core file\n");
- fflush(stderr);
- my_write_core(sig);
- }
-#endif
-
-#ifndef __WIN__
- /* On Windows, do not terminate, but pass control to exception filter */
- exit(1);
-#endif
-}
-
#if !defined(__WIN__) && !defined(__NETWARE__)
#ifndef SA_RESETHAND
#define SA_RESETHAND 0
@@ -2664,9 +2506,9 @@ static void init_signals(void)
my_init_stacktrace();
#endif
#if defined(__amiga__)
- sa.sa_handler=(void(*)())handle_segfault;
+ sa.sa_handler=(void(*)())handle_fatal_signal;
#else
- sa.sa_handler=handle_segfault;
+ sa.sa_handler=handle_fatal_signal;
#endif
sigaction(SIGSEGV, &sa, NULL);
sigaction(SIGABRT, &sa, NULL);
@@ -4363,6 +4205,10 @@ int win_main(int argc, char **argv)
int main(int argc, char **argv)
#endif
{
+#ifdef HAVE_NPTL
+ ld_assume_kernel_is_set= (getenv("LD_ASSUME_KERNEL") != 0);
+#endif
+
MY_INIT(argv[0]); // init my_sys library & pthreads
/* nothing should come before this line ^^^ */
@@ -7876,7 +7722,7 @@ static int mysql_init_variables(void)
opt_secure_file_priv= 0;
opt_bootstrap= opt_myisam_log= 0;
mqh_used= 0;
- segfaulted= kill_in_progress= 0;
+ kill_in_progress= 0;
cleanup_done= 0;
defaults_argc= 0;
defaults_argv= 0;