How to dump core

[Christian Smith]

In article <B5cna.60949$jVh.46894@news01.bloor.is.net.cable.r ogers.com>,
"Samuel T" <none@none.com> writes:

> Hi all,
> env: gnu/linux/pthread/g++..
> My code has a hard-to-reproduce segfault, but in gdb, it disappeared. The
> app doesn't autogenerate coredump, so how can I generate it outside gdb?

May be a bit late now, but try installing pthread_kill_other_threads_np() as
the signal handler for all your fault signals:
struct sigaction sa = { 0 };

/*
* Set the handler for SEGV, BUS, ILL and ABRT to the Linux thread
* function below, to kill the threads so we can produce a core dump.
* It should be safe using pthread_kill_other_threads_np directly,
* as it takes no arguments (will ignore the signo) and returns void
* also.
*/
sa.sa_handler = pthread_kill_other_threads_np;
sa.sa_flags = SA_RESETHAND | SA_RESTART;

sigaction( SIGSEGV, &sa, NULL );
sigaction( SIGBUS, &sa, NULL );
sigaction( SIGILL, &sa, NULL );
sigaction( SIGABRT, &sa, NULL );

We used this to good effect for debugging our code on Linux, but you do lose
the information on the other threads. Better than nothing, however.

Christian

--
"You have not converted a man because you have silenced him." -John Morley

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[Haran Shivanan]

module "Christian Smith" core dumped with the following output:

> In article <B5cna.60949$jVh.46894@news01.bloor.is.net.cable.r ogers.com>,
> "Samuel T" <none@none.com> writes:

>> Hi all,
>> env: gnu/linux/pthread/g++..
>> My code has a hard-to-reproduce segfault, but in gdb, it disappeared. The
>> app doesn't autogenerate coredump, so how can I generate it outside gdb?

I don't seem to have the original thread so I'm replying here.
Have you already tried abort().
This should generate a core file.