From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:33080) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UdK7h-0001yL-0V for qemu-devel@nongnu.org; Fri, 17 May 2013 08:51:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UdK7c-00012x-0N for qemu-devel@nongnu.org; Fri, 17 May 2013 08:51:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29263) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UdK7b-00012b-Nj for qemu-devel@nongnu.org; Fri, 17 May 2013 08:50:55 -0400 Message-ID: <519627AC.6010305@redhat.com> Date: Fri, 17 May 2013 09:50:52 -0300 From: Lucas Meneghel Rodrigues MIME-Version: 1.0 References: <1368780720-14852-1-git-send-email-stefanha@redhat.com> <87obcaaq4b.fsf@blackfin.pond.sub.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] tests: set MALLOC_PERTURB_ to expose memory bugs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Markus Armbruster , Stefan Hajnoczi , qemu-devel On 17/05/13 08:15 AM, Stefan Hajnoczi wrote: > On Fri, May 17, 2013 at 11:54 AM, Markus Armbruster wrote: >> Stefan Hajnoczi writes: >> >>> glibc wipes malloc(3) memory when the MALLOC_PERTURB_ environment >>> variable is set. The value of the environment variable determines the >>> bit pattern used to wipe memory. For more information, see >>> http://udrepper.livejournal.com/11429.html. >>> >>> Set MALLOC_PERTURB_ for gtester and qemu-iotests. Note we always set >>> the environment variable to 1 so the test is deterministic. Setting a >>> random variable might expose more bugs but would be harder to reproduce. >>> >>> Both make check and qemu-iotests pass with MALLOC_PERTURB_ enabled. >>> >>> Signed-off-by: Stefan Hajnoczi >>> --- >>> Lucas noticed KVM autotest failures when enabling MALLOC_PERTURB_. By enabling >>> it for in-tree test suites we can detect memory management errors earlier. >>> >>> tests/Makefile | 4 +++- >>> tests/qemu-iotests/check | 2 +- >>> 2 files changed, 4 insertions(+), 2 deletions(-) >>> >>> diff --git a/tests/Makefile b/tests/Makefile >>> index a307d5a..25f6d28 100644 >>> --- a/tests/Makefile >>> +++ b/tests/Makefile >>> @@ -171,6 +171,7 @@ GCOV_OPTIONS = -n $(if $(V),-f,) >>> $(patsubst %, check-qtest-%, $(QTEST_TARGETS)): check-qtest-%: $(check-qtest-y) >>> $(if $(CONFIG_GCOV),@rm -f *.gcda */*.gcda */*/*.gcda */*/*/*.gcda,) >>> $(call quiet-command,QTEST_QEMU_BINARY=$*-softmmu/qemu-system-$* \ >>> + MALLOC_PERTURB_=1 \ >>> gtester $(GTESTER_OPTIONS) -m=$(SPEED) $(check-qtest-$*-y),"GTESTER $@") >>> $(if $(CONFIG_GCOV),@for f in $(gcov-files-$*-y); do \ >>> echo Gcov report for $$f:;\ >> >> If you want punishment, why not go for extra punishment? >> >> MALLOC_PERTURB_=$(($RANDOM % 255 + 1)) > > Covered in the commit description: > "Note we always set > the environment variable to 1 so the test is deterministic. Setting a > random variable might expose more bugs but would be harder to reproduce." > > I didn't want to clutter output with "MALLOC_PERTURB_=123" on every > run. AFAIK we have no log where this can be silently stashed. I > guess we could write it to a file and add that to .gitignore. Yes, you could consider to have a debug log or something similar.