From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51539) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wk8uX-0005s5-6R for qemu-devel@nongnu.org; Tue, 13 May 2014 05:22:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wk8uR-0003RT-O6 for qemu-devel@nongnu.org; Tue, 13 May 2014 05:22:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9123) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wk8uR-0003RI-Gg for qemu-devel@nongnu.org; Tue, 13 May 2014 05:22:03 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s4D9M2r3023352 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 13 May 2014 05:22:03 -0400 Date: Tue, 13 May 2014 17:22:11 +0800 From: Fam Zheng Message-ID: <20140513092211.GD26360@T430.nay.redhat.com> References: <1399970763-8102-1-git-send-email-armbru@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1399970763-8102-1-git-send-email-armbru@redhat.com> Subject: Re: [Qemu-devel] [PATCH] qemu-iotests: Fix core dump suppression in test 039 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: kwolf@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com On Tue, 05/13 10:46, Markus Armbruster wrote: > The shell script attempts to suppress core dumps like this: > > old_ulimit=$(ulimit -c) > ulimit -c 0 > $QEMU_IO arg... > ulimit -c "$old_ulimit" > > This breaks the test hard unless the limit was zero to begin with! > ulimit sets both hard and soft limit by default, and (re-)raising the > hard limit requires privileges. Broken since it was added in commit > dc68afe. > > Could be fixed by adding -S to set only the soft limit, but I'm not > sure how portable that is in practice. Simply do it in a subshell > instead, like this: > > (ulimit -c 0; exec $QEMU_IO arg...) > > Signed-off-by: Markus Armbruster > --- > tests/qemu-iotests/039 | 18 ++++++------------ > 1 file changed, 6 insertions(+), 12 deletions(-) > > diff --git a/tests/qemu-iotests/039 b/tests/qemu-iotests/039 > index b9cbe99..182b0f0 100755 > --- a/tests/qemu-iotests/039 > +++ b/tests/qemu-iotests/039 > @@ -67,10 +67,8 @@ echo "== Creating a dirty image file ==" > IMGOPTS="compat=1.1,lazy_refcounts=on" > _make_test_img $size > > -old_ulimit=$(ulimit -c) > -ulimit -c 0 # do not produce a core dump on abort(3) > -$QEMU_IO -c "write -P 0x5a 0 512" -c "abort" "$TEST_IMG" | _filter_qemu_io > -ulimit -c "$old_ulimit" > +(ulimit -c 0 # do not produce a core dump on abort(3) > +exec $QEMU_IO -c "write -P 0x5a 0 512" -c "abort" "$TEST_IMG") | _filter_qemu_io This works well. But when I try to put this in a function to avoid repeating: function _no_dump_exec() { (ulimit -c 0; exec "$@") } _no_dump_exec $QEMU_IO -c "write -P 0x5a 0 512" -c "abort" "$TEST_IMG") | _filter_qemu_io it doesn't work: 039 1s ... - output mismatch (see 039.out.bad) --- 039.out 2014-05-13 12:10:39.248866480 +0800 +++ 039.out.bad 2014-05-13 17:19:46.161986618 +0800 @@ -9,6 +9,7 @@ == Creating a dirty image file == Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 +./039: line 51: 10517 Aborted "$@" wrote 512/512 bytes at offset 0 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) incompatible_features 0x1 Any idea what the difference is here? Thanks, Fam > > # The dirty bit must be set > ./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features > @@ -103,10 +101,8 @@ echo "== Opening a dirty image read/write should repair it ==" > IMGOPTS="compat=1.1,lazy_refcounts=on" > _make_test_img $size > > -old_ulimit=$(ulimit -c) > -ulimit -c 0 # do not produce a core dump on abort(3) > -$QEMU_IO -c "write -P 0x5a 0 512" -c "abort" "$TEST_IMG" | _filter_qemu_io > -ulimit -c "$old_ulimit" > +(ulimit -c 0 # do not produce a core dump on abort(3) > +exec $QEMU_IO -c "write -P 0x5a 0 512" -c "abort" "$TEST_IMG") | _filter_qemu_io > > # The dirty bit must be set > ./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features > @@ -122,10 +118,8 @@ echo "== Creating an image file with lazy_refcounts=off ==" > IMGOPTS="compat=1.1,lazy_refcounts=off" > _make_test_img $size > > -old_ulimit=$(ulimit -c) > -ulimit -c 0 # do not produce a core dump on abort(3) > -$QEMU_IO -c "write -P 0x5a 0 512" -c "abort" "$TEST_IMG" | _filter_qemu_io > -ulimit -c "$old_ulimit" > +(ulimit -c 0 # do not produce a core dump on abort(3) > +exec $QEMU_IO -c "write -P 0x5a 0 512" -c "abort" "$TEST_IMG") | _filter_qemu_io > > # The dirty bit must not be set since lazy_refcounts=off > ./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features > -- > 1.8.1.4 > >