From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 1EE4C3857C4C for ; Wed, 19 Oct 2022 13:27:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1EE4C3857C4C Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666186077; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=6Kiy2j17FlWkknWv7MwRjoaiKZ2ANEE2NJhHDN4fQ3o=; b=UwjpNoeN42IjkE0DSbwNytJLH7fFcyXdEHMsmyxLpWYBEvG/6K1KHbHFi3C9oOeFkvoCns Zm/3UpJfCfUaUIBSLCLl+HDH6hPvFE8TIP+Ws6ALjoEzERrKrtCEDi4dm/mz/u0lgEBh5v GEl0GRPz8jgqTpAORZPAOBwYDSulDck= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-352-ezjgUPHyNaiAL9H7oSjNsQ-1; Wed, 19 Oct 2022 09:27:56 -0400 X-MC-Unique: ezjgUPHyNaiAL9H7oSjNsQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6604B803D48; Wed, 19 Oct 2022 13:27:56 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.193.252]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 267C4C15BA5; Wed, 19 Oct 2022 13:27:55 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 29JDRrsm3957809 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 19 Oct 2022 15:27:53 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 29JDRqKc3957808; Wed, 19 Oct 2022 15:27:52 +0200 Date: Wed, 19 Oct 2022 15:27:52 +0200 From: Jakub Jelinek To: Andrew Stubbs Cc: "gcc-patches@gcc.gnu.org" Subject: Re: [PATCH] libgomp: fix hang on fatal error Message-ID: Reply-To: Jakub Jelinek References: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-9.8 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_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,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 List-Id: On Fri, Oct 14, 2022 at 06:04:06PM +0100, Andrew Stubbs wrote: > This patch fixes a problem in which fatal errors inside mutex-locked regions > (i.e. basically anything in the plugin) will cause it to hang up trying to > take the lock to clean everything up. > > Using abort() instead of exit(1) bypasses the atexit handlers and solves the > problem. > > OK for mainline? > > Andrew > libgomp: fix hang on fatal error > > Don't try to clean up if a fatal error occurs in libgomp. Typically the > cleanup is not reentrant so we end up hung on a lock. > > libgomp/ChangeLog: > > * error.c (gomp_vfatal): Use abort instead of exit. > > diff --git a/libgomp/error.c b/libgomp/error.c > index 50ed85eedb1..25548c14a82 100644 > --- a/libgomp/error.c > +++ b/libgomp/error.c > @@ -77,7 +77,7 @@ void > gomp_vfatal (const char *fmt, va_list list) > { > gomp_verror (fmt, list); > - exit (EXIT_FAILURE); > + abort (); > } > > void I don't like this, abort has quite different user visible behavior from exit, e.g. the former often dumps core. I believe in most places libgomp handles this by releasing locks before calling gomp_{,v}fatal: gomp_mutex_unlock (®ister_lock); gomp_fatal ("Out of memory allocating %lu bytes", (unsigned long) size); gomp_mutex_unlock (&devicep->lock); gomp_fatal ("Copying of %s object [%p..%p) to %s object [%p..%p) failed", src, srcaddr, srcaddr + size, dst, dstaddr, dstaddr + size); etc. I could live with a gomp_fatal/gomp_vfatal alternative that would use _exit/_Exit (but not sure if it is supported on all targets where libgomp is) for uses where releasing locks is for whatever reason not an option. Jakub