From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42249) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WkC3B-00056p-U3 for qemu-devel@nongnu.org; Tue, 13 May 2014 08:43:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WkC36-0002qQ-G9 for qemu-devel@nongnu.org; Tue, 13 May 2014 08:43:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47099) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WkC36-0002qK-1o for qemu-devel@nongnu.org; Tue, 13 May 2014 08:43:12 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s4DChB8e013740 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Tue, 13 May 2014 08:43:11 -0400 Date: Tue, 13 May 2014 20:43:21 +0800 From: Fam Zheng Message-ID: <20140513124321.GF26360@T430.nay.redhat.com> References: <1399970763-8102-1-git-send-email-armbru@redhat.com> <20140513092211.GD26360@T430.nay.redhat.com> <871tvxdig3.fsf@blackfin.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871tvxdig3.fsf@blackfin.pond.sub.org> 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 13:30, Markus Armbruster wrote: > Fam Zheng writes: > > > 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 "$@" > > wrote 512/512 bytes at offset 0 > > 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) > > incompatible_features 0x1 > > > > Any idea what the difference is here? > > Full patch of your version, please. Here it goes: diff --git a/tests/qemu-iotests/039 b/tests/qemu-iotests/039 index b9cbe99..27544f9 100755 --- a/tests/qemu-iotests/039 +++ b/tests/qemu-iotests/039 @@ -47,6 +47,13 @@ _supported_os Linux _default_cache_mode "writethrough" _supported_cache_modes "writethrough" +function _no_dump_exec() +{ + ( + ulimit -c 0 + "$@") +} + size=128M echo @@ -67,10 +74,7 @@ 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" +_no_dump_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