From patchwork Thu Sep 30 12:06:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 45603 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 11AD23857C4F for ; Thu, 30 Sep 2021 12:08:15 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 11AD23857C4F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1633003695; bh=XhcevgxjMkAidbm1GIAA6uxb3hUqQiqodKVibKuUqjA=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=txTEKoD+w1B71guM8ahOo2dEIicVV3lNtENceMGLZ3VX9ge5hIqKUW+0SGbu5eyzP beX/waA0R0D+qymM4ATDFD7glN1JurV/ZTx7aEy01vym2PQqWxjPz6QpFTSX0oFnKD VBGQGkb1BrAhDmIo21Vp4ZLCjE6GyGsIHztEdrng= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTP id 1A1F43858415 for ; Thu, 30 Sep 2021 12:06:57 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1A1F43858415 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-1-tmWboXvlN3eATDPWtccGrQ-1; Thu, 30 Sep 2021 08:06:55 -0400 X-MC-Unique: tmWboXvlN3eATDPWtccGrQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 65329801B3D for ; Thu, 30 Sep 2021 12:06:54 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.176]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B891A60657 for ; Thu, 30 Sep 2021 12:06:53 +0000 (UTC) To: libc-alpha@sourceware.org Subject: [PATCH] support: Add check for TID zero in support_wait_for_thread_exit Date: Thu, 30 Sep 2021 14:06:51 +0200 Message-ID: <878rze4690.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) 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: , X-Patchwork-Original-From: Florian Weimer via Libc-alpha From: Florian Weimer Reply-To: Florian Weimer Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Some kernel versions (observed with kernel 5.14 and earlier) can list "0" entries in /proc/self/task. This happens when a thread exits while the task list is being constructed. Treat this entry as not present, like the proposed kernel patch does: [PATCH] procfs: Do not list TID 0 in /proc//task Reviewed-by: Carlos O'Donell Tested-by: Carlos O'Donell --- support/support_wait_for_thread_exit.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/support/support_wait_for_thread_exit.c b/support/support_wait_for_thread_exit.c index 658a813810..5e3be421a7 100644 --- a/support/support_wait_for_thread_exit.c +++ b/support/support_wait_for_thread_exit.c @@ -43,7 +43,10 @@ support_wait_for_thread_exit (void) return; } - if (strcmp (e->d_name, ".") == 0 || strcmp (e->d_name, "..") == 0) + /* In some kernels, "0" entries denote a thread that has just + exited. */ + if (strcmp (e->d_name, ".") == 0 || strcmp (e->d_name, "..") == 0 + || strcmp (e->d_name, "0") == 0) continue; int task_tid = atoi (e->d_name);