From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 499E2C46CA1 for ; Mon, 18 Sep 2023 18:58:02 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qiJRD-0007Tf-LB; Mon, 18 Sep 2023 14:57:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiJRB-0007TA-W6 for qemu-devel@nongnu.org; Mon, 18 Sep 2023 14:57:38 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qiJRA-0006qR-FG for qemu-devel@nongnu.org; Mon, 18 Sep 2023 14:57:37 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id CE83022060; Mon, 18 Sep 2023 18:57:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1695063454; h=from:from:reply-to: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=HSDWtE/9wGS9ZX+x+RMmDZiWUy7GnIJ0iBVWO4/YHXc=; b=XsU2/YMZqqP0jjy0GQyVBtzoFl+rdEyS/vYNjTu9kHj4vxP5A5kGprBzWHisWqnxyrQN4e pCc8KU6BnO8F2Y+lOR4aDS9Q4JVdkcEaG+mFiJi0uKOoa+WKj0IHV5D/6LsCu8HVh58Fm6 hxgTS6fEF4D/tJimE1kBxuHjeqmmefY= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1695063454; h=from:from:reply-to: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=HSDWtE/9wGS9ZX+x+RMmDZiWUy7GnIJ0iBVWO4/YHXc=; b=aR3oNJUzj0Kk954HpQ+uzuH368kg58cxFwkhwbS+Q+CNcqv4f3nmHg+bGwGNeRIhjkdzD4 KLbLVzzm/aEQXkAg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 56EFD13480; Mon, 18 Sep 2023 18:57:34 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id apL5CJ6dCGVTPgAAMHmgww (envelope-from ); Mon, 18 Sep 2023 18:57:34 +0000 From: Fabiano Rosas To: Markus Armbruster , qemu-devel@nongnu.org Cc: quintela@redhat.com, peterx@redhat.com, leobras@redhat.com Subject: Re: [PATCH 16/52] migration/rdma: Fix io_writev(), io_readv() methods to obey contract In-Reply-To: <20230918144206.560120-17-armbru@redhat.com> References: <20230918144206.560120-1-armbru@redhat.com> <20230918144206.560120-17-armbru@redhat.com> Date: Mon, 18 Sep 2023 15:57:31 -0300 Message-ID: <87wmwnxqas.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=195.135.220.28; envelope-from=farosas@suse.de; helo=smtp-out1.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Markus Armbruster writes: > QIOChannelClass methods qio_channel_rdma_readv() and > qio_channel_rdma_writev() violate their method contract when > rdma->error_state is non-zero: > > 1. They return whatever is in rdma->error_state then. Only -1 will be > fine. -2 will be misinterpreted as "would block". Anything less > than -2 isn't defined in the contract. A positive value would be > misinterpreted as success, but I believe that's not actually > possible. > > 2. They neglect to set an error then. If something up the call stack > dereferences the error when failure is returned, it will crash. If > it ignores the return value and checks the error instead, it will > miss the error. > > Crap like this happens when return statements hide in macros, > especially when their uses are far away from the definition. > > I elected not to investigate how callers are impacted. > > Expand the two bad macro uses, so we can set an error and return -1. > The next commit will then get rid of the macro altogether. > > Signed-off-by: Markus Armbruster Reviewed-by: Fabiano Rosas