---------- Původní zpráva ----------
Od: Lennart Poettering <mzerqung@0pointer.de>
Komu: Development discussions related to Fedora <devel@lists.fedoraproject.org>
Datum: 19. 12. 2016 13:51:09
Předmět: Re: Creating cores in f25

On Mon, 19.12.16 00:07, Tom Hughes (tom@compton.nu) wrote:

> On 18/12/16 23:08, Matthew Miller wrote:
> > On Sun, Dec 18, 2016 at 01:00:37PM -0600, Michael Catanzaro wrote:
> > > > How do I get f25 to create cores, these days?
> > > Some more details here:
> > > https://fedoraproject.org/wiki/Changes/coredumpctl
> >
> > I have ulimit -c returning 0 in shells on my system — have I done some
> > configuration I don't remember? That's the default, isn't it? Should it
> > stay that way with this change?
>
> The ulimit on core dump size is (mostly) ignored if sysctl has been used to
> tell the kernel to send core dumps to a pipe.
>
> The only exception is that a limit of 1 byte (which is impossible to set in
> most shells) effectively acts as a limit of 0 and disables core dumps but
> that's only because the kernel uses it internally to ignore core dumps from
> the process running the pipe to receive a core dump.

Note that "systemd-coredump" will honour the resource limit anyway,
even if the kernel ignores it as soon as a core_pattern is
installed. I am pretty sure we should honour resource limits if they
are set, as they are pretty OK and well-documented way how to enable
and disable coredump collection, and well, putting limits on them.

Note that abrtd (to my knowledge) ignores the resource limit, and will
collect coredumps in anyway if if disabled with it.

ABRT does not ignore the resource limit. If the limit is not 0, ABRT creates a core file according the value of 'sysctl kernel.core_pattern' before it was changed to ABRT pattern. This basically means that ABRT creates core file in prorcess' CWD if the limit (ulimit -c) is not 0. This is the behavior we are used to.

However, it is true that ABRT creates a core dump file in /var/spool/abrt/ regardless of the limit.

It is possible to tell kernel to skip core dumping at all by setting "RLIMIT_CORE" to 1.

Regards,

Jakub