Crash during shutdown in Master_info_index::any_slave_sql_running (compiled with GCC v6)

Thread 1 (Thread 0x7f5475f85700 (LWP 28787)):

#0  __pthread_kill (threadid=<optimized out>, signo=signo@entry=11) at ../sysdeps/unix/sysv/linux/pthread_kill.c:62

#1  0x0000000000ab88ba in my_write_core (sig=sig@entry=11) at /home/vicentiu/Workspace/debian/mariadb-10.0/mysys/stacktrace.c:457

#2  0x00000000006eb6a2 in handle_fatal_signal (sig=11) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/signal_handler.cc:262

#3  <signal handler called>

#4  Master_info_index::any_slave_sql_running (this=0x0) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/rpl_mi.cc:1288

#5  0x00000000005290b1 in show_slaves_running (thd=<optimized out>, var=<optimized out>, buff=0x7f5475f821b0 "0") at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/mysqld.cc:7319

#6  0x0000000000602bbe in show_status_array (thd=thd@entry=0x7f546dadf008, wild=wild@entry=0x0, variables=0x7f54733fec50, value_type=value_type@entry=OPT_SESSION, status_var=status_var@entry=0x7f5475f83d40, prefix=prefix@entry=0xbf7436 "", table=0x7f546c00a020, ucase_names=false, cond=0x0) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_show.cc:3057

#7  0x000000000060746f in fill_status (thd=0x7f546dadf008, tables=0x7f546c019348, cond=<optimized out>) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_show.cc:7476

#8  0x000000000060cb9f in get_schema_tables_result (join=join@entry=0x7f546c019d30, executed_place=executed_place@entry=PROCESSED_BY_JOIN_EXEC) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_show.cc:8280

#9  0x00000000005f4ace in JOIN::exec_inner (this=this@entry=0x7f546c019d30) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_select.cc:2538

#10 0x00000000005f68a9 in JOIN::exec (this=0x7f546c019d30) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_select.cc:2373

#11 0x00000000005f375d in mysql_select (thd=thd@entry=0x7f546dadf008, rref_pointer_array=rref_pointer_array@entry=0x7f546dae31a8, tables=0x7f546c019348, wild_num=<optimized out>, fields=..., conds=<optimized out>, og_num=0, order=0x0, group=0x0, having=0x0, proc_param=0x0, select_options=2684619520, result=0x7f546c019d10, unit=0x7f546dae2840, select_lex=0x7f546dae2f30) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_select.cc:3308

#12 0x00000000005f40ef in handle_select (thd=thd@entry=0x7f546dadf008, lex=lex@entry=0x7f546dae2778, result=result@entry=0x7f546c019d10, setup_tables_done_option=setup_tables_done_option@entry=0) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_select.cc:361

#13 0x00000000005a1147 in execute_sqlcom_select (thd=thd@entry=0x7f546dadf008, all_tables=all_tables@entry=0x7f546c019348) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_parse.cc:5293

#14 0x00000000005ab62d in execute_show_status (all_tables=0x7f546c019348, thd=0x7f546dadf008) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_parse.cc:5314

#15 mysql_execute_command (thd=thd@entry=0x7f546dadf008) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_parse.cc:2492

#16 0x00000000005aefd0 in mysql_parse (thd=0x7f546dadf008, rawbuf=<optimized out>, length=11, parser_state=0x7f5475f84650) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_parse.cc:6574

#17 0x00000000005b0bed in dispatch_command (command=<optimized out>, thd=0x7f546dadf008, packet=<optimized out>, packet_length=<optimized out>) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_parse.cc:1308

#18 0x00000000005b164b in do_command (thd=<optimized out>) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_parse.cc:998

#19 0x0000000000662a0b in do_handle_one_connection (thd_arg=thd_arg@entry=0x7f546dadf008) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_connect.cc:1378

#20 0x0000000000662a58 in handle_one_connection (arg=arg@entry=0x7f546dadf008) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/sql_connect.cc:1293

#21 0x00000000008381e4 in pfs_spawn_thread (arg=0x7f547306d608) at /home/vicentiu/Workspace/debian/mariadb-10.0/storage/perfschema/pfs.cc:1860

#22 0x00007f54750cc6fa in start_thread (arg=0x7f5475f85700) at pthread_create.c:333

#23 0x00007f5473eaab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f5475f3c700 (LWP 28791)):

#0  0x00007f5473ea0d13 in select () at ../sysdeps/unix/syscall-template.S:84

#1  0x0000000000ab65db in my_sleep (m_seconds=m_seconds@entry=20000) at /home/vicentiu/Workspace/debian/mariadb-10.0/mysys/my_sleep.c:29

#2  0x000000000052d32d in close_connections () at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/mysqld.cc:1676

#3  kill_server (sig_ptr=0x0) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/mysqld.cc:1859

#4  0x000000000052d5ee in kill_server_thread (arg=arg@entry=0x7f5475fcdd9c) at /home/vicentiu/Workspace/debian/mariadb-10.0/sql/mysqld.cc:1887

#5  0x00000000008381e4 in pfs_spawn_thread (arg=0x7f546c425208) at /home/vicentiu/Workspace/debian/mariadb-10.0/storage/perfschema/pfs.cc:1860

#6  0x00007f54750cc6fa in start_thread (arg=0x7f5475f3c700) at pthread_create.c:333

#7  0x00007f5473eaab5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

/**

   Master_info_index::any_slave_sql_running()

   The LOCK_active_mi must be held while calling this function.

   @return

   0            No Slave SQL thread is running

   #		Number of slave SQL thread running

*/

uint Master_info_index::any_slave_sql_running()

{

  uint count= 0;

  DBUG_ENTER("any_slave_sql_running");

  if (!this) // master_info_index is set to NULL on server shutdown

    DBUG_RETURN(count);

  for (uint i= 0; i< master_info_hash.records; ++i)

  {

    Master_info *mi= (Master_info *)my_hash_element(&master_info_hash, i);

    if (mi->rli.slave_running != MYSQL_SLAVE_NOT_RUN)

      count++;

  }

  DBUG_RETURN(count);

}

1283:/home/vicentiu/Workspace/MariaDB/sql/rpl_mi.cc ****   uint count= 0;

1284:/home/vicentiu/Workspace/MariaDB/sql/rpl_mi.cc ****   DBUG_ENTER("any_slave_sql_running");

1285:/home/vicentiu/Workspace/MariaDB/sql/rpl_mi.cc ****   if (!this) // master_info_index is set to NULL on server shutdown

 4675              		.loc 1 1285 0

 4676 1fe0 4885FF   		testq	%rdi, %rdi

 4677 1fe3 0F84AF00 		je	.L397

 4677      0000

1282:/home/vicentiu/Workspace/MariaDB/sql/rpl_mi.cc ****   uint count= 0;

printf("%p", this);