core file not created on a segmentation fault on ARM

2
votes

I have a arm executable[ (Debug build) ELF 32 bit LSB executable, ARM version (SYSV)] process executing on ARM Cortex A9 target having Linux OS(KErnel 2.6.38.8 )

The process has user id root groupid root

Even when the process crashes after getting SIGSEGV, there is no core file generated. Now I have read this question to ensure it has file system is writable, ulimit -c is unlimited, user is root and has permissions, but still something is missing.

Here are few outputs of certain varaibles of my process and system, related to a core file creation :

cat /proc//coredump_filter is 00000033

cat /proc/sys/kernel/core_pattern is core

cat /proc/sys/kernel/core_uses_pid is 0

I have tried everything but stumped.

Could there be any kernel config/build option disabling the core creation?

Any other pointers?

EDIT: I did simple test as below and it created a core file, but my process crash still does not dump core file.

sleep 20 &
killall -SIGSEGV sleep
1
linuxarmcore
Why do you think your process has crashed? If it catches a signal, then a core file will not be generated. Try adding an atexit() or other hook. You can wrap your code in a shell script to verify if it exits normally or not. – artless noise
Because I see it receiving SIGSEGV, and there is no signal handler set for that as i know it. – goldenmean
How do you see it receiving? Via a debugger, with strace, or some other way? Whatever tool you are using may circumvent the core generation. – artless noise
@artless noise There is no tool or debugger attached. Just on the console , i see that process receiving SIGSEGV. – goldenmean

1 Answers

1
votes

Could there be any kernel config/build option disabling the core creation?

It is hidden under General Setup|Embedded System or General Setup|Configure standard... depending on your Linux version. The symbol value is ELF_CORE and it is in init/Kconfig. If it is not enabled, you will never get core dumps.

As suggested in a hidden comment in why coredump file is not generated.