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 37C7EC87FC9 for ; Tue, 29 Jul 2025 12:17:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ugjFu-00058M-Fe; Tue, 29 Jul 2025 08:16:31 -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 1ugjFn-0004yp-3W for qemu-devel@nongnu.org; Tue, 29 Jul 2025 08:16:23 -0400 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 1ugjFh-0000Z3-U3 for qemu-devel@nongnu.org; Tue, 29 Jul 2025 08:16:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753791373; 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=qYQNJTCIjaqgIf0WG029oeIURdgJtQpqR14Z9B6FwXo=; b=hq8vh497qESMM3FIMMy8WAZj/Z10jZJ592iWfKSZNqgjr+6DgLCrk4V0pbrc+xEJ6KwSAl KhlXlq2BqFdrmjzjtek3m1ElMZ1l+kKvFfnd3+KIwLRgBLeaR7b346GdI7OiPatk/M9vQI 4WFIBPbkpr32tIbthVbO5xHLlT1uxtU= Received: from mx-prod-mc-06.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-214-Y5_RWBEgNdiWutH50DJmuw-1; Tue, 29 Jul 2025 08:16:07 -0400 X-MC-Unique: Y5_RWBEgNdiWutH50DJmuw-1 X-Mimecast-MFC-AGG-ID: Y5_RWBEgNdiWutH50DJmuw_1753791366 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8F82918002B2; Tue, 29 Jul 2025 12:16:05 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.14]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C2A3E18003FC; Tue, 29 Jul 2025 12:16:04 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1971221E6A27; Tue, 29 Jul 2025 14:16:02 +0200 (CEST) From: Markus Armbruster To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Cc: qemu-devel@nongnu.org, sstabellini@kernel.org, anthony@xenproject.org, paul@xen.org, edgar.iglesias@gmail.com, xen-devel@lists.xenproject.org, qemu-trivial@nongnu.org Subject: Re: [PATCH] hw/display/xenfb: Replace unreachable code by abort() In-Reply-To: <14fff91b-7434-4d90-adb1-ebbe3f51d605@linaro.org> ("Philippe =?utf-8?Q?Mathieu-Daud=C3=A9=22's?= message of "Tue, 29 Jul 2025 13:26:02 +0200") References: <20250729111226.3627499-1-armbru@redhat.com> <14fff91b-7434-4d90-adb1-ebbe3f51d605@linaro.org> Date: Tue, 29 Jul 2025 14:16:02 +0200 Message-ID: <87v7nbdwfx.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 10.30.177.93 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable 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 Philippe Mathieu-Daud=C3=A9 writes: > On 29/7/25 13:12, Markus Armbruster wrote: >> xenfb_mouse_event() has a switch statement whose controlling >> expression move->axis is an enum InputAxis. The enum values are >> INPUT_AXIS_X and INPUT_AXIS_Y, encoded as 0 and 1. The switch has a >> case for both axes. In addition, it has an unreachable default label. >> This convinces Coverity that move->axis can be greater than 1. It >> duly reports a buffer overrun when it is used to subscript an array >> with two elements. >> Replace the unreachable code by abort(). >> Resolves: Coverity CID 1613906 >> Signed-off-by: Markus Armbruster >> --- >> hw/display/xenfb.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c >> index 22822fecea..5e6c691779 100644 >> --- a/hw/display/xenfb.c >> +++ b/hw/display/xenfb.c >> @@ -283,8 +283,7 @@ static void xenfb_mouse_event(DeviceState *dev, Qemu= Console *src, >> scale =3D surface_height(surface) - 1; >> break; >> default: >> - scale =3D 0x8000; >> - break; >> + abort(); > > We prefer GLib g_assert_not_reached() over abort() because it displays > the file, line number & function before aborting. The purpose of this line is to tell the compiler we can't get there, with the least amount of ceremony. We have ~600 calls of abort(). Whoever merges this: feel free to replace by g_assert_not_reached(). >> } >> xenfb->axis[move->axis] =3D move->value * scale / 0x7fff; >> }