From nobody Wed Dec 17 05:37:10 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1510169042695553.6925643705061; Wed, 8 Nov 2017 11:24:02 -0800 (PST) Received: from localhost ([::1]:33602 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eCVww-00014a-Mt for importer@patchew.org; Wed, 08 Nov 2017 14:23:46 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40956) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eCVu9-0007jr-Su for qemu-devel@nongnu.org; Wed, 08 Nov 2017 14:20:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eCVu8-0001Ac-SH for qemu-devel@nongnu.org; Wed, 08 Nov 2017 14:20:53 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38490) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eCVu8-00019v-LU for qemu-devel@nongnu.org; Wed, 08 Nov 2017 14:20:52 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D20AFC04AC56; Wed, 8 Nov 2017 19:20:51 +0000 (UTC) Received: from localhost (ovpn-116-145.ams2.redhat.com [10.36.116.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id E5E1E60BE3; Wed, 8 Nov 2017 19:20:48 +0000 (UTC) From: Stefan Hajnoczi To: Date: Wed, 8 Nov 2017 19:20:42 +0000 Message-Id: <20171108192043.10682-2-stefanha@redhat.com> In-Reply-To: <20171108192043.10682-1-stefanha@redhat.com> References: <20171108192043.10682-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 08 Nov 2017 19:20:51 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL for-2.11-rc1 v2 1/2] tests-aio-multithread: fix /aio/multi/schedule race condition X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Stefan Hajnoczi Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" test_multi_co_schedule_entry() set to_schedule[id] in the final loop iteration before terminating the coroutine. There is a race condition where the main thread attempts to enter the terminating or terminated coroutine when signalling coroutines to stop: atomic_mb_set(&now_stopping, true); for (i =3D 0; i < NUM_CONTEXTS; i++) { ctx_run(i, finish_cb, NULL); <--- enters dead coroutine! to_schedule[i] =3D NULL; } Make sure only to set to_schedule[id] if this coroutine really needs to be scheduled! Reported-by: "R.Nageswara Sastry" Signed-off-by: Stefan Hajnoczi Reviewed-by: Paolo Bonzini Message-id: 20171106190233.1175-1-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- tests/test-aio-multithread.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/tests/test-aio-multithread.c b/tests/test-aio-multithread.c index 549d784915..d396185972 100644 --- a/tests/test-aio-multithread.c +++ b/tests/test-aio-multithread.c @@ -144,17 +144,16 @@ static void finish_cb(void *opaque) static coroutine_fn void test_multi_co_schedule_entry(void *opaque) { g_assert(to_schedule[id] =3D=3D NULL); - atomic_mb_set(&to_schedule[id], qemu_coroutine_self()); =20 while (!atomic_mb_read(&now_stopping)) { int n; =20 n =3D g_test_rand_int_range(0, NUM_CONTEXTS); schedule_next(n); + + atomic_mb_set(&to_schedule[id], qemu_coroutine_self()); qemu_coroutine_yield(); - g_assert(to_schedule[id] =3D=3D NULL); - atomic_mb_set(&to_schedule[id], qemu_coroutine_self()); } } =20 --=20 2.13.6