From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42861) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fkFf6-00056Z-FV for qemu-devel@nongnu.org; Mon, 30 Jul 2018 17:25:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fkFf1-0007sp-QU for qemu-devel@nongnu.org; Mon, 30 Jul 2018 17:25:04 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40102 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fkFf1-0007qj-KV for qemu-devel@nongnu.org; Mon, 30 Jul 2018 17:24:59 -0400 References: <20180723193530.20891-1-eblake@redhat.com> <87in553zsx.fsf@dusky.pond.sub.org> <8c082bfd-6753-c8d2-cfcd-e2be77c3f763@redhat.com> <878t5zxpc2.fsf@dusky.pond.sub.org> From: Eric Blake Message-ID: Date: Mon, 30 Jul 2018 16:24:55 -0500 MIME-Version: 1.0 In-Reply-To: <878t5zxpc2.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 for-3.0] tests/libqtest: Improve kill_qemu() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: peter.maydell@linaro.org, mst@redhat.com, f4bug@amsat.org, qemu-devel@nongnu.org, alex.bennee@linaro.org, rth@twiddle.net On 07/25/2018 11:17 AM, Markus Armbruster wrote: >> >> the output was produced by bash, which uses waitpid() - and therefore >> the fact that bash reports the core dump even when no core file is >> created is promising. > > Proof beats plausibility argument: > > $ cat wcordump.c > $ gcc -Wall -g -O wcordump.c > $ (ulimit -c unlimited; ./a.out) > sig 6 128 > $ (ulimit -c 0; ./a.out) > sig 6 0 Doesn't match my results: $ (ulimit -c 0; ./a.out) sig 6 128 So, what's different between our two environments? kernel 4.17.7-100.fc27.x86_64 $ echo /proc/sys/kernel/core_* /proc/sys/kernel/core_pattern /proc/sys/kernel/core_pipe_limit /proc/sys/kernel/core_uses_pid $ cat /proc/sys/kernel/core_* |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %e 0 1 > > Looks like WCOREDUMP() does depend on my ulimit -c. Or worse, that its behavior is kernel/environment-sensitive. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org