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 [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id 3729F3AA9C55 for ; Thu, 24 Jun 2021 11:19:38 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3729F3AA9C55 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-189-K8VpwsniMxaK6AldgI-oAw-1; Thu, 24 Jun 2021 07:19:35 -0400 X-MC-Unique: K8VpwsniMxaK6AldgI-oAw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C87E41019985; Thu, 24 Jun 2021 11:19:34 +0000 (UTC) Received: from oldenburg.str.redhat.com (ovpn-112-228.ams2.redhat.com [10.36.112.228]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EE4191A26A; Thu, 24 Jun 2021 11:19:33 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: Adhemerval Zanella via Libc-alpha Subject: Re: [PATCH v4 2/4] posix: Do not clobber errno by atfork handlers References: <20210623184354.395316-1-adhemerval.zanella@linaro.org> <20210623184354.395316-3-adhemerval.zanella@linaro.org> <877dijn097.fsf@oldenburg.str.redhat.com> <30080b5b-33ae-27a8-3031-2785022a17c9@linaro.org> Date: Thu, 24 Jun 2021 13:19:32 +0200 In-Reply-To: <30080b5b-33ae-27a8-3031-2785022a17c9@linaro.org> (Adhemerval Zanella's message of "Thu, 24 Jun 2021 08:05:54 -0300") Message-ID: <87zgvfjyrf.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 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-12.7 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_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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-List-Received-Date: Thu, 24 Jun 2021 11:19:40 -0000 * Adhemerval Zanella: > On 24/06/2021 05:19, Florian Weimer wrote: >> * Adhemerval Zanella via Libc-alpha: >> >>> Checked on x86_64-linux-gnu. >>> --- >>> posix/fork.c | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/posix/fork.c b/posix/fork.c >>> index 44caf8d166..9340511198 100644 >>> --- a/posix/fork.c >>> +++ b/posix/fork.c >>> @@ -103,6 +103,9 @@ __libc_fork (void) >>> } >>> else >>> { >>> + /* If _Fork failed, preserve its errno value. */ >>> + int save_errno = errno; >>> + >>> /* Release acquired locks in the multi-threaded case. */ >>> if (multiple_threads) >>> { >>> @@ -115,6 +118,8 @@ __libc_fork (void) >>> >>> /* Run the handlers registered for the parent. */ >>> __run_fork_handlers (atfork_run_parent, multiple_threads); >>> + >>> + __set_errno (save_errno); >> >> I think you should restrict the __set_errno call to pid < 0, so that >> errno is not 0 after a different value has been observed by the fork >> handlers. > > OK, I can change it back. From the previous review iteration I understood > you were ok with making it unconditional [1]. > > [1] https://sourceware.org/pipermail/libc-alpha/2021-March/123729.html Sorry, I meant making the saving unconditional, not the restoring. Florian