Application crashes, but no core dump generated

Question

I have an issue where my application keeps on dumping core after few day/weeks, but unfortunately, generates no core dump.

We tried to set ulimit -c unlimited with no success, so we incorporated setrlimit functionality in the code itself, but had no luck with that approach either. And, on top of that, we added MALLOC_CHECK_ too.

Interestingly, when we tried to initiate a manual core dump (using kill -ABRT <pid>), it did generate a core dump.

I could see the following message in /var/log/message

kernel: [2302077.396021] myapp[22140]: segfault at 54552e42 ip 00000000f773f36f sp 00000000fffdc48c error 4 in ld-2.11.3.so[f7727000+1f000]

Environment: sles11

Any suggestions on how to make the application generate core dumps more reliably?

Solution

Many current systems are configured so they don't leave core dumps (the average user doesn't know what to do with them).

• Make sure you start the process where it can dump core (writable directory, enough space; I'm not sure if a directory change in the process might interfere here)
• Make sure to give the "ulimit -c unlimited" in the same shell starting the process
• If the program is SUID or SGID, the kernel will refuse to make it dump core for security reasons, take a look at this question for guidance

Comments

[kbickar]

Also worth checking the file /proc/sys/kernal/core_pattern to see where the corefiles will be put. /etc/sysctl.conf has a similar one but can be set more permanently.