From patchwork Thu Dec 29 23:42:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Samuel Thibault X-Patchwork-Id: 62484 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id D5E9A3858280 for ; Thu, 29 Dec 2022 23:42:26 +0000 (GMT) X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from sonata.ens-lyon.org (domu-toccata.ens-lyon.fr [140.77.166.138]) by sourceware.org (Postfix) with ESMTPS id 6F53A3858C53 for ; Thu, 29 Dec 2022 23:42:13 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6F53A3858C53 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=ens-lyon.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=bounce.ens-lyon.org Received: from localhost (localhost [127.0.0.1]) by sonata.ens-lyon.org (Postfix) with ESMTP id AAD4020100; Fri, 30 Dec 2022 00:42:11 +0100 (CET) Received: from sonata.ens-lyon.org ([127.0.0.1]) by localhost (sonata.ens-lyon.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LlL7OQRyktkC; Fri, 30 Dec 2022 00:42:11 +0100 (CET) Received: from begin.home (lfbn-orl-1-1261-6.w86-244.abo.wanadoo.fr [86.244.81.6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by sonata.ens-lyon.org (Postfix) with ESMTPSA id 98481200FD; Fri, 30 Dec 2022 00:42:10 +0100 (CET) Received: from samy by begin.home with local (Exim 4.96) (envelope-from ) id 1pB2XK-00CIdN-0k; Fri, 30 Dec 2022 00:42:10 +0100 From: Samuel Thibault To: libc-alpha@sourceware.org Cc: Samuel Thibault , commit-hurd@gnu.org Subject: [hurd,commited] htl: Fix sem_wait race between read and gsync_wait Date: Fri, 30 Dec 2022 00:42:10 +0100 Message-Id: <20221229234210.2931558-1-samuel.thibault@ens-lyon.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-Spam-Status: No, score=-13.2 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" If the value changes between sem_wait's read and the gsync_wait call, the kernel will return KERN_INVALID_ARGUMENT, which we have to interpret as the value having already changed. This fixes applications (e.g. libgo) seeing sem_wait erroneously return KERN_INVALID_ARGUMENT. --- sysdeps/htl/sem-timedwait.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sysdeps/htl/sem-timedwait.c b/sysdeps/htl/sem-timedwait.c index 1b1eec9f59..c610804b08 100644 --- a/sysdeps/htl/sem-timedwait.c +++ b/sysdeps/htl/sem-timedwait.c @@ -79,7 +79,7 @@ __sem_timedwait_internal (sem_t *restrict sem, ((unsigned int *) &sem->data) + SEM_VALUE_OFFSET, 0, flags); - if (err != 0) + if (err != 0 && err != KERN_INVALID_ARGUMENT) { /* Error, interruption or timeout, abort. */ if (err == KERN_TIMEDOUT) @@ -138,7 +138,7 @@ __sem_timedwait_internal (sem_t *restrict sem, err = __lll_wait_intr (&isem->value, SEM_NWAITERS_MASK, flags); - if (err != 0) + if (err != 0 && err != KERN_INVALID_ARGUMENT) { /* Error, interruption or timeout, abort. */ if (err == KERN_TIMEDOUT)