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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 5FC9DC433EF for ; Sat, 28 May 2022 11:52:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=eLXg99WvnABchxi11tgFELumIp1UOWMWiZW498DP+K4=; b=GS439O7jJDEJEp LqBLbkehCbi1bgLrcYyAcRX2EiIWhKT0DTezs393hDznwt1U5HTEKg0exhVVJpTauhwecgVxOjqMu fhb2WEiyCO5ew5cx3Zbj7VzEI8SSmbCEZ/Nl6RxJq8popuYym7+LQd3W3USs8EC3CXzyzrwCon/sk ITxs5B4MSudeEb6Pwxb1KHU21dtyqUSZipPWuTIv3htnk9uQ/juFHkmuvN75Gi8wUGfbIV2IXHxHN xCPaW0yTgsKBxNayPb88U4GdTGvuEinm2LW8jJ8UHQYp5w1Qe4+TD/edJqHIz5dkvVdRnn70Phuwa HB+fXc3pUKG1ajh1y9Wg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nuuy0-00247d-7k; Sat, 28 May 2022 11:50:48 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nuuxG-0023rH-IM for linux-arm-kernel@lists.infradead.org; Sat, 28 May 2022 11:50:03 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B951160E8E; Sat, 28 May 2022 11:50:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BB4EC34118; Sat, 28 May 2022 11:50:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653738601; bh=yyB4hR+igLzaHP7EAyqgeD9ghacZPHl0R9Sq6ANIVOE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d3vYl542YFv3IJ9osmVM4WSi2218X2VpMsUOjpQIk6V//UZCY3OyLyTE89mS2HWij xjQEi4/vXRFLY0Uzc4kquuaK9PHcgPcQd235V5DlQ1zsPBKJBOjQyCGN2r++BZQ4Hy vv/k+M1zNA9cWp7lQBDOYcjkAnH2oUk/zR2EERAKCmL1q7S3vrlSyY8gUns3KDYcKL wygZU3xYRzy2Qdej5T/fM/NuiA42DLJJUdVlfxnjLR5HraWuGUB8bCEgf/9kWZJWUb aavW18bnw9JXPyqYa3o0sKOGwM2kcy54nWICEH6tPKFUyvIQHxFYpma3Qp3LDnUEbJ yVHW8JysbIuLA== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nuumD-00EEGh-DD; Sat, 28 May 2022 12:38:37 +0100 From: Marc Zyngier To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: James Morse , Suzuki K Poulose , Alexandru Elisei , Oliver Upton , Will Deacon , Fuad Tabba , Quentin Perret , Mark Brown , kernel-team@android.com Subject: [PATCH 16/18] KVM: arm64: Add build-time sanity checks for flags Date: Sat, 28 May 2022 12:38:26 +0100 Message-Id: <20220528113829.1043361-17-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220528113829.1043361-1-maz@kernel.org> References: <20220528113829.1043361-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, oupton@google.com, will@kernel.org, tabba@google.com, qperret@google.com, broonie@kernel.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220528_045002_771044_DC0B7C51 X-CRM114-Status: GOOD ( 14.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Flags are great, but flags can also be dangerous: it is easy to encode a flag that is bigger than its container (unless the container is a u64), and it is easy to construct a flag value that doesn't fit in the mask that is associated with it. Add a couple of build-time sanity checks that ensure we catch these two cases. Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_host.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 4073a33af17c..70931231f0cb 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -420,8 +420,20 @@ struct kvm_vcpu_arch { } steal; }; +#define __build_check_flag(v, flagset, f, m) \ + do { \ + typeof(v->arch.flagset) *_fset; \ + \ + /* Check that the flags fit in the mask */ \ + BUILD_BUG_ON(HWEIGHT(m) != HWEIGHT((f) | (m))); \ + /* Check that the flags fit in the type */ \ + BUILD_BUG_ON((sizeof(*_fset) * 8) <= __fls(m)); \ + } while (0) + #define __vcpu_get_flag(v, flagset, f, m) \ ({ \ + __build_check_flag(v, flagset, f, m); \ + \ v->arch.flagset & (m); \ }) @@ -429,6 +441,8 @@ struct kvm_vcpu_arch { do { \ typeof(v->arch.flagset) *fset; \ \ + __build_check_flag(v, flagset, f, m); \ + \ fset = &v->arch.flagset; \ if (HWEIGHT(m) > 1) \ *fset &= ~(m); \ @@ -439,6 +453,8 @@ struct kvm_vcpu_arch { do { \ typeof(v->arch.flagset) *fset; \ \ + __build_check_flag(v, flagset, f, m); \ + \ fset = &v->arch.flagset; \ *fset &= ~(m); \ } while (0) -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel