Commit 5ceb394f authored by unknown's avatar unknown
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Bug#15869 Cannot shutdown the server - it restarts 

 - A segfault occured when the function 'kill_server' called 
   'my_sigset' with signal number 0. 'my_sigset' is a macro which
   uses 'sigaction' to install the signal handler with an invalid
   signal number will on most platforms return EINVAL but yields
   a segfauilt on IRIX 6.5
 - The server crash was detected by mysqld_safe and it was restarted although
   a shutdown was requested. 
 - Semantics of kill_server(0) is not known, leaving it intact


include/my_pthread.h:
  Check return value from sigaction with a DBUG_ASSERT
  Also DBUG_ASSERT if signal number 0 is passed
sql/mysqld.cc:
  Don't call my_sigset if signo is 0
parent 1bdb7f77

include/my_pthread.h

+4 −2
Original line number Diff line number Diff line
@@ -329,12 +329,14 @@ int sigwait(sigset_t *setp, int *sigp); /* Use our implemention */ 
  we want to make sure that no such flags are set.

*/

#if defined(HAVE_SIGACTION) && !defined(my_sigset)

#define my_sigset(A,B) do { struct sigaction s; sigset_t set;              \

#define my_sigset(A,B) do { struct sigaction s; sigset_t set; int rc;      \

                            DBUG_ASSERT((A) != 0);                         \

                            sigemptyset(&set);                             \

                            s.sa_handler = (B);                            \

                            s.sa_mask    = set;                            \

                            s.sa_flags   = 0;                              \

                            sigaction((A), &s, (struct sigaction *) NULL); \

                            rc= sigaction((A), &s, (struct sigaction *) NULL);\

                            DBUG_ASSERT(rc == 0);                          \

                          } while (0)

#elif defined(HAVE_SIGSET) && !defined(my_sigset)

#define my_sigset(A,B) sigset((A),(B))

sql/mysqld.cc

+2 −1
Original line number Diff line number Diff line
@@ -884,6 +884,7 @@ static void __cdecl kill_server(int sig_ptr) 
    RETURN_FROM_KILL_SERVER;

  kill_in_progress=TRUE;

  abort_loop=1;					// This should be set

  if (sig != 0) // 0 is not a valid signal number

    my_sigset(sig,SIG_IGN);

  if (sig == MYSQL_KILL_SIGNAL || sig == 0)

    sql_print_information(ER(ER_NORMAL_SHUTDOWN),my_progname);