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tso0rxp · Posted: Tue Sep 30, 2003 5:35 am Post subject:

Passing this issue to the forum for one of my contract programming group... Background.. (we are running v5.2 MQ CSD05G). Daemon is written in C++. No FDC files generated. CORE comes from daemon, not MQ Series.

ISSUE:
The daemon that runs on the Solaris 2.6 gets a SIGSEGV during a MQDISC. The SIGCHLD being captured and handled the original process executes while the Child that calls the MQDISC is terminated leaving a CORE file.

Debugging:
We use the GDB debugger and the trace of the Stack is as below:
#0 0xfee42744 in t_delete () from /usr/lib/libc.so.1
(gdb) where
#0 0xfee42744 in t_delete () from /usr/lib/libc.so.1
#1 0xfee423c4 in realfree () from /usr/lib/libc.so.1
#2 0xfee42bd4 in _free_unlocked () from /usr/lib/libc.so.1
#3 0xfee42b24 in free () from /usr/lib/libc.so.1
#4 0xff05bf24 in xcsFreeMem () from /usr/lib/libmqmcs.so
#5 0xff1da090 in zstDeletePCD () from /usr/lib/libmqm.so
#6 0xff1d0674 in zstMQDISC () from /usr/lib/libmqm.so
#7 0xff1ccb88 in MQDISC () from /usr/lib/libmqm.so
#8 0x000525f8 in HMQMgr::disconnect() (this=0x164c68) at hmqmgr.cc:116
#9 0x00036048 in HSmartAgent::postProcess() (this=0x16b308)
at HSmartAgent.cc:300No symbol table info available.

The detailed Stack for the Frames 6 and higher are printed below to verify the Completion Code and the Reason Code

#6 0xff1d0674 in zstMQDISC () from /usr/lib/libmqm.so
No symbol table info available.
#7 0xff1ccb88 in MQDISC () from /usr/lib/libmqm.so
No symbol table info available.
#8 0x000525f8 in HMQMgr::disconnect() (this=0x164c68) at hmqmgr.cc:116
qp = (class HMQQue *) 0x0
np = (HMQQue *) 0x0
cc = 0
rc = 0
#9 0x00036048 in HSmartAgent::postProcess() (this=0x16b308)
at HSmartAgent.cc:300
g = (class HSA_Globals *) 0x15ce40
nextAgent = (HSmartAgent *) 0x0

Sporadic Nature:
The Cores are generated randomly. In trying to duplicate the Core, the same data when transmitted several times results in the Core, not just running it once or twice.

Comments:
The MQDISC is also passed a Valid parameters : These are in line with the function prototype in the MQ Version we run on the box. The following is the print from the

$>>>>>>>>>>>more /var/sadm/pkg/mqm-upd05/save/opt/mqm/inc/cmqc.h file that provides the prototypes.
----
void MQENTRY MQDISC (
PMQHCONN pHconn, /* Connection handle */
PMQLONG pCompCode, /* Completion code */
PMQLONG pReason); /* Reason code qualifying CompCode */
_________________
Bob Perry
MQ Administrator