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dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55850 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lFJdI-0007Oy-5e for qemu-devel@archiver.kernel.org; Thu, 25 Feb 2021 11:36:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:37040) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lFJaw-0005c5-Hy for qemu-devel@nongnu.org; Thu, 25 Feb 2021 11:34:30 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:60354) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lFJam-0003EB-0c for qemu-devel@nongnu.org; Thu, 25 Feb 2021 11:34:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614270855; 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=TDBtJAKM1hfJ0ZC5sq+ZLKQyEG0Bd3zlsgkwaHiNwHM=; b=Xdabr5jDi09TkUSi2Dl9reV5rFgW4fLIiD7B/HqTmRpz52seylNuA1WV9qrqe7IRxOOmF2 vd9rst75PnS6RfPi/bGUKUKckXnVxyZZqKVOo+O5XaVGzIlad8NEaWAlJCSxikWvj10/Z+ fNngdF9rgz2HJ/kDQNPEvqV7d+SIg3g= 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-499-LaDyMwwMNoumiUDW88VYgw-1; Thu, 25 Feb 2021 11:34:13 -0500 X-MC-Unique: LaDyMwwMNoumiUDW88VYgw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0EA10835E23; Thu, 25 Feb 2021 16:34:11 +0000 (UTC) Received: from [10.36.112.150] (ovpn-112-150.ams2.redhat.com [10.36.112.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1418A60855; Thu, 25 Feb 2021 16:34:00 +0000 (UTC) Subject: Re: [PATCH v2 1/7] intel_iommu: Fix mask may be uninitialized in vtd_context_device_invalidate To: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , eric.auger.pro@gmail.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, jean-philippe@linaro.org, peterx@redhat.com, jasowang@redhat.com, pbonzini@redhat.com References: <20210225091435.644762-1-eric.auger@redhat.com> <20210225091435.644762-2-eric.auger@redhat.com> <2e75abf8-55e4-b5db-7ca2-6e0408bf81e6@redhat.com> From: Auger Eric Message-ID: <420d0048-e2a9-2571-9f4c-45341c7a3355@redhat.com> Date: Thu, 25 Feb 2021 17:33:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <2e75abf8-55e4-b5db-7ca2-6e0408bf81e6@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eric.auger@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=eric.auger@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 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, NICE_REPLY_A=-0.435, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: vivek.gautam@arm.com, shameerali.kolothum.thodi@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi Philippe, On 2/25/21 11:08 AM, Philippe Mathieu-Daudé wrote: > On 2/25/21 10:14 AM, Eric Auger wrote: >> With -Werror=maybe-uninitialized configuration we get >> ../hw/i386/intel_iommu.c: In function ‘vtd_context_device_invalidate’: >> ../hw/i386/intel_iommu.c:1888:10: error: ‘mask’ may be used >> uninitialized in this function [-Werror=maybe-uninitialized] >> 1888 | mask = ~mask; >> | ~~~~~^~~~~~~ >> >> Add a g_assert_not_reached() to avoid the error. >> >> Signed-off-by: Eric Auger >> --- >> hw/i386/intel_iommu.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c >> index b4f5094259..3206f379f8 100644 >> --- a/hw/i386/intel_iommu.c >> +++ b/hw/i386/intel_iommu.c >> @@ -1884,6 +1884,8 @@ static void vtd_context_device_invalidate(IntelIOMMUState *s, >> case 3: >> mask = 7; /* Mask bit 2:0 in the SID field */ >> break; >> + default: >> + g_assert_not_reached(); >> } >> mask = ~mask; > > Unrelated to this patch, but I wonder why we don't directly assign the > correct value of the mask in the switch cases... After reading the vtd spec again, I think this is aligned with the spec description. FM = function mask encodes the bits to mask. Then you actually compute the mask by ~mask. > > Reviewed-by: Philippe Mathieu-Daudé Thanks! Eric > > set the mask > diuse the >> >> >