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 E46EDCFD2F6 for ; Tue, 2 Dec 2025 08:33:16 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vQLon-0001Qr-Nv; Tue, 02 Dec 2025 03:33:05 -0500 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 1vQLon-0001PE-58 for qemu-devel@nongnu.org; Tue, 02 Dec 2025 03:33:05 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vQLol-0007PW-R7 for qemu-devel@nongnu.org; Tue, 02 Dec 2025 03:33:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764664382; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=I+nyeIgdjao7kmFECITLfLNQv0kuOpWPLNI5c0Bl9fQ=; b=dzBkXyl1PK9sn+9Z6/CbNEXTIf+DKv9WNeD8uqe8MJtHLqFTeg39de9yvzfYiyaJ8JR+46 glcKLTL9f+cVjwVu3Okn49CdAd3lGA/CLWbPYGpkvB8L3woct80UkE5LSshwR2vkdmOnR1 FY9IrJf2JbXrw5FCrn7SnEEvQMdaCCg= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-630-Fuj5WPnsNf69QYD5NAGJ2A-1; Tue, 02 Dec 2025 03:33:00 -0500 X-MC-Unique: Fuj5WPnsNf69QYD5NAGJ2A-1 X-Mimecast-MFC-AGG-ID: Fuj5WPnsNf69QYD5NAGJ2A_1764664379 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 50E4A1800451; Tue, 2 Dec 2025 08:32:59 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.7]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D50201800361; Tue, 2 Dec 2025 08:32:58 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 8C4E421E6A27; Tue, 02 Dec 2025 09:32:56 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Cc: pbonzini@redhat.com, kvm@vger.kernel.org, eesposit@redhat.com, philmd@linaro.org Subject: Re: [PATCH v2] kvm: Fix kvm_vm_ioctl() and kvm_device_ioctl() return value In-Reply-To: <20251128152050.3417834-1-armbru@redhat.com> (Markus Armbruster's message of "Fri, 28 Nov 2025 16:20:50 +0100") References: <20251128152050.3417834-1-armbru@redhat.com> Date: Tue, 02 Dec 2025 09:32:56 +0100 Message-ID: <871pldxozr.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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: > These functions wrap ioctl(). When ioctl() fails, it sets @errno. > The wrappers then return that @errno negated. > > Except they call accel_ioctl_end() between calling ioctl() and reading > @errno. accel_ioctl_end() can clobber @errno, e.g. when a futex() > system call fails. Seems unlikely, but it's a bug all the same. > > Fix by retrieving @errno before calling accel_ioctl_end(). > > Fixes: a27dd2de68f3 (KVM: keep track of running ioctls) > Signed-off-by: Markus Armbruster > Reviewed-by: Philippe Mathieu-Daud=C3=A9 Queued for 10.2.