From nobody Tue Feb 10 23:12:03 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7CE8C77B7D for ; Wed, 10 May 2023 14:40:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237556AbjEJOka (ORCPT ); Wed, 10 May 2023 10:40:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237111AbjEJOkW (ORCPT ); Wed, 10 May 2023 10:40:22 -0400 Received: from gnuweeb.org (gnuweeb.org [51.81.211.47]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 552A86EB5; Wed, 10 May 2023 07:40:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gnuweeb.org; s=default; t=1683729615; bh=SKIms/x8UkuCSr7MMpMwCUwu5UFRx/RZRLA+rEglAko=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jZseRr+FoEyBwmEDpOSOuV1XqLGTpFkp1YdWeGNopmPeGlzWr+noMhhYkVGLQNh3t 4UsvxDcUNQ5HXZZ7Sy/uoPqRg0fLJuIHMmL0UU/3CAYhAwyohY6O/b/5qNVLaOsuZY wjhMsT8NASw5rWXUj6PPGo9iS0Va3Vi2NusYDoOEFIGi1J0RXwxDFO6SH5Cqr6llv2 yRXVxl59iYbuDsvrxKCnqAKB81J6o0cmRUQo0fKBaVN8xTZeXQZF5Yj2Co+tkCFI7M +ifDSBzTkmRGiRBL6QdyHiSWyfjL29BjyFJw+ypvllEQv/nsEjshIN0PZGK3g30KEx kGzk4Cd/aI+DA== Received: from integral2.. (unknown [101.128.114.135]) by gnuweeb.org (Postfix) with ESMTPSA id B13FE245CF1; Wed, 10 May 2023 21:40:13 +0700 (WIB) From: Ammar Faizi To: Jens Axboe Cc: Ammar Faizi , =?UTF-8?q?Barnab=C3=A1s=20P=C5=91cze?= , Michael William Jonathan , Linux Kernel Mailing List , io-uring Mailing List , GNU/Weeb Mailing List Subject: [PATCH liburing v1 2/2] recv-msgall: Fix invalid mutex usage Date: Wed, 10 May 2023 21:39:27 +0700 Message-Id: <20230510143927.123170-3-ammarfaizi2@gnuweeb.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230510143927.123170-1-ammarfaizi2@gnuweeb.org> References: <20230510143927.123170-1-ammarfaizi2@gnuweeb.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Calling pthread_mutex_lock() twice with the same mutex in the same thread without unlocking it first is invalid. The intention behind this pattern was to wait for the recv_fn() thread to be ready. Use the pthread barrier instead. It is more straightforward and correct. Fixes: https://github.com/axboe/liburing/issues/855 Reported-by: Barnab=C3=A1s P=C5=91cze Signed-off-by: Ammar Faizi --- test/recv-msgall.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/test/recv-msgall.c b/test/recv-msgall.c index f809834b2e427fc5..d1fcdb0d510423e7 100644 --- a/test/recv-msgall.c +++ b/test/recv-msgall.c @@ -19,7 +19,7 @@ #define HOST "127.0.0.1" static __be16 bind_port; struct recv_data { - pthread_mutex_t mutex; + pthread_barrier_t barrier; int use_recvmsg; struct msghdr msg; }; @@ -122,11 +122,11 @@ static void *recv_fn(void *data) =20 ret =3D t_create_ring_params(1, &ring, &p); if (ret =3D=3D T_SETUP_SKIP) { - pthread_mutex_unlock(&rd->mutex); + pthread_barrier_wait(&rd->barrier); ret =3D 0; goto err; } else if (ret < 0) { - pthread_mutex_unlock(&rd->mutex); + pthread_barrier_wait(&rd->barrier); goto err; } =20 @@ -135,7 +135,7 @@ static void *recv_fn(void *data) fprintf(stderr, "recv_prep failed: %d\n", ret); goto err; } - pthread_mutex_unlock(&rd->mutex); + pthread_barrier_wait(&rd->barrier); ret =3D do_recv(&ring); close(sock); io_uring_queue_exit(&ring); @@ -219,28 +219,24 @@ err: =20 static int test(int use_recvmsg) { - pthread_mutexattr_t attr; pthread_t recv_thread; struct recv_data rd; int ret; void *retval; =20 - pthread_mutexattr_init(&attr); - pthread_mutexattr_setpshared(&attr, 1); - pthread_mutex_init(&rd.mutex, &attr); - pthread_mutex_lock(&rd.mutex); + pthread_barrier_init(&rd.barrier, NULL, 2); rd.use_recvmsg =3D use_recvmsg; =20 ret =3D pthread_create(&recv_thread, NULL, recv_fn, &rd); if (ret) { fprintf(stderr, "Thread create failed: %d\n", ret); - pthread_mutex_unlock(&rd.mutex); return 1; } =20 - pthread_mutex_lock(&rd.mutex); + pthread_barrier_wait(&rd.barrier); do_send(); pthread_join(recv_thread, &retval); + pthread_barrier_destroy(&rd.barrier); return (intptr_t)retval; } =20 --=20 Ammar Faizi