Any tips on using gdb to step through the code?
[postg...@va-mp-db02 ~]$ file /usr/local/pgsql/bin/postgres /usr/local/pgsql/bin/postgres: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.18, not stripped ---- Pg Log --- <[unkno...@[unknown] 2009-10-16 12:33:33.600 EDT>LOG: 00000: connection received: host=10.0.20.38 port=57014 <[unkno...@[unknown] 2009-10-16 12:33:33.600 EDT>LOCATION: BackendInitialize, postmaster.c:3259 <[unkno...@[unknown] 10.0.20.38(57014) 2009-10-16 12:33:33.629 EDT>DEBUG: 00000: SSL connection from "(anonymous)" <[unkno...@[unknown] 10.0.20.38(57014) 2009-10-16 12:33:33.629 EDT>LOCATION: open_server_SSL, be-secure.c:961 <rdoug...@tacacs 10.0.20.38(57014) 2009-10-16 12:33:33.634 EDT>DEBUG: 00000: SSL: read alert (0x0100) <rdoug...@tacacs 10.0.20.38(57014) 2009-10-16 12:33:33.634 EDT>LOCATION: info_cb, be-secure.c:699 <rdoug...@tacacs 10.0.20.38(57014) 2009-10-16 12:33:33.634 EDT>LOG: 08006: could not receive data from client: Connection reset by peer <rdoug...@tacacs 10.0.20.38(57014) 2009-10-16 12:33:33.634 EDT>LOCATION: pq_recvbuf, pqcomm.c:769 <rdoug...@tacacs 10.0.20.38(57014) 2009-10-16 12:33:33.634 EDT>LOG: 00000: RD - passwd is NULL... returning PAM_CONV_ERR <rdoug...@tacacs 10.0.20.38(57014) 2009-10-16 12:33:33.634 EDT>LOCATION: pam_passwd_conv_proc, auth.c:1906 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: reaping dead processes <@ 2009-10-16 12:33:33.641 EDT>LOCATION: reaper, postmaster.c:2236 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: server process (PID 2257) was terminated by signal 11: Segmentation fault <@ 2009-10-16 12:33:33.641 EDT>LOCATION: LogChildExit, postmaster.c:2725 <@ 2009-10-16 12:33:33.641 EDT>LOG: 00000: server process (PID 2257) was terminated by signal 11: Segmentation fault <@ 2009-10-16 12:33:33.641 EDT>LOCATION: LogChildExit, postmaster.c:2725 <@ 2009-10-16 12:33:33.641 EDT>LOG: 00000: terminating any other active server processes <@ 2009-10-16 12:33:33.641 EDT>LOCATION: HandleChildCrash, postmaster.c:2552 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: sending SIGQUIT to process 2251 <@ 2009-10-16 12:33:33.641 EDT>LOCATION: HandleChildCrash, postmaster.c:2621 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: sending SIGQUIT to process 2252 <@ 2009-10-16 12:33:33.641 EDT>LOCATION: HandleChildCrash, postmaster.c:2633 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: shmem_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.641 EDT>LOCATION: shmem_exit, ipc.c:197 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: proc_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.641 EDT>LOCATION: proc_exit_prepare, ipc.c:169 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: shmem_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.641 EDT>LOCATION: shmem_exit, ipc.c:197 <@ 2009-10-16 12:33:33.641 EDT>DEBUG: 00000: proc_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.641 EDT>LOCATION: proc_exit_prepare, ipc.c:169 <@ 2009-10-16 12:33:33.643 EDT>DEBUG: 00000: sending SIGQUIT to process 2253 <@ 2009-10-16 12:33:33.643 EDT>LOCATION: HandleChildCrash, postmaster.c:2645 <@ 2009-10-16 12:33:33.643 EDT>DEBUG: 00000: sending SIGQUIT to process 2254 <@ 2009-10-16 12:33:33.643 EDT>LOCATION: HandleChildCrash, postmaster.c:2675 <@ 2009-10-16 12:33:33.643 EDT>DEBUG: 00000: shmem_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.643 EDT>LOCATION: shmem_exit, ipc.c:197 <@ 2009-10-16 12:33:33.643 EDT>DEBUG: 00000: proc_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.643 EDT>LOCATION: proc_exit_prepare, ipc.c:169 <@ 2009-10-16 12:33:33.643 EDT>DEBUG: 00000: shmem_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.643 EDT>LOCATION: shmem_exit, ipc.c:197 <@ 2009-10-16 12:33:33.643 EDT>DEBUG: 00000: proc_exit(-1): 0 callbacks to make <@ 2009-10-16 12:33:33.643 EDT>LOCATION: proc_exit_prepare, ipc.c:169 <@ 2009-10-16 12:33:33.644 EDT>DEBUG: 00000: reaping dead processes <@ 2009-10-16 12:33:33.644 EDT>LOCATION: reaper, postmaster.c:2236 <@ 2009-10-16 12:33:33.644 EDT>DEBUG: 00000: reaping dead processes <@ 2009-10-16 12:33:33.644 EDT>LOCATION: reaper, postmaster.c:2236 <@ 2009-10-16 12:33:33.644 EDT>LOG: 00000: all server processes terminated; reinitializing -----Original Message----- From: Tom Lane [mailto:t...@sss.pgh.pa.us] Sent: Friday, October 16, 2009 12:19 PM To: Douglas, Ryan Cc: pgsql-bugs@postgreSQL.org Subject: Re: [BUGS] BUG #5121: Segmentation Fault when using pam w/ krb5 "Douglas, Ryan" <rdoug...@arbinet.com> writes: > Program terminated with signal 11, Segmentation fault. > #0 0x0000000000559624 in pam_passwd_conv_proc () > Missing separate debuginfos, use: debuginfo-install audit-libs-1.7.13-1.fc11.x86_64 > (gdb) bt > #0 0x0000000000559624 in pam_passwd_conv_proc () > #1 0x00007f738dfeedd8 in _pam_krb5_conv_call (pamh=<value optimized out>, messages=0xb51780, n_prompts=0, responses=0x7fff2e356668) at conv.c:99 > #2 0x00007f738dfefb38 in _pam_krb5_generic_prompter (context=<value optimized out>, data=0x7fff2e357fe0, name=<value optimized out>, banner=<value optimized out>, num_prompts=1, > prompts=<value optimized out>, suppress_password_prompts=1) at prompter.c:330 Actually, now that I look more closely at that stack trace, pam_passwd_conv_proc *is* a Postgres function --- so the core dump is happening when libpam calls us back. (I wonder why gdb failed to present any information about it? Are you using a stripped postgres executable?) In a quick look at the source for pam_passwd_conv_proc, the only very plausible explanation for why it would segfault in isolated cases seems to be that the initial sanity check on the passed-in message status might be assuming more than it should --- in particular it would obviously dump core if msg is null or msg[0] is null. I am thinking that maybe, when the KDC is Active Directory and there's no password supplied already, libpam makes additional calls to the conv_proc with parameter values that we're not prepared to handle. Can you add additional debug printouts or step through the code and verify what's happening there? regards, tom lane -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
