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 60A95EC0463 for ; Tue, 3 Mar 2026 09:12:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4hy9xICo1EPoOGuMUjTJL88qGfqc1hJzlCloLKGWnZI=; b=1Q41htR6k+B3/W1Vz6Pnrwp3xO CMZrmKOGN+1+nz/JOsqBwCQHnCvEZ1OHHF4CrQ20lj4qQKNcFhXKjy8t3ubI1MMbvRFdVP3qde7by SVfBYASDksM0yGrXNeayAMDl8wMIvMtuPhsH6PhXCdPHR4lPygu0kv2wP9NBmqW7Go6Z3rni7++Mp /TWDgm44QvULK8upM+3pYHVLkmgRN5lpIQFA1WdC77Z2QqkopJHRyfq6v6VqiXcNPuID3BfKwEc2A icHiHRo4xc5YBfD0E+JI58sxS7B/mizHiLuj8w0ZFK76rfenEQfRqnHJazgugLo4ADPqO/o+a5zZy +u5SWjng==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxLng-0000000EqO3-3mkK; Tue, 03 Mar 2026 09:12:20 +0000 Received: from mail-wm1-x334.google.com ([2a00:1450:4864:20::334]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vxLnd-0000000EqN9-2Gf5 for linux-arm-kernel@lists.infradead.org; Tue, 03 Mar 2026 09:12:19 +0000 Received: by mail-wm1-x334.google.com with SMTP id 5b1f17b1804b1-4837f27cf2dso48066055e9.2 for ; Tue, 03 Mar 2026 01:12:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1772529135; x=1773133935; darn=lists.infradead.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=4hy9xICo1EPoOGuMUjTJL88qGfqc1hJzlCloLKGWnZI=; b=d9Q2s3elOXsLJT/Y0sreTUJd9SijpueosTJalBQuZVgKf6rQrsEDGQi6s7CWE7K1XS MA+J/x9lFfxnw2HDPKtB3UyKkRV9V1/8+x6gSH3qVOvCAHKxZNaFf7fxsKghN2ti30AQ O4OZrbgJh+eQAMK4EEIb5JTVNU68QOy9rOAS4eulrxBCSudsFcwG4mCT/QSmg81V5Mm5 8MOgRkNBm7MFuS2zFkgWY4JrICrXd0SKGxBdkTpvrXt8Ugx57jqaP/yajRhCBpr0BYZZ 3kKY8XxjEe4gG2j+B79j3tftkiYqxd5vwonwXQBhHUUwSLFD9W/ydGbblrEacIDQ5kep 4sTQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772529135; x=1773133935; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=4hy9xICo1EPoOGuMUjTJL88qGfqc1hJzlCloLKGWnZI=; b=gsFLuCstLIo3c5WSTzaQd83BrNnumCzAVxfK9bQDT62BeorI3IJ/6Hz60D8TALsrnd EWLjWJWkjgj3aST1iygMGguHhFrAeiRBluMiGkOxmm0IYDCRgwnDqiLNRTNC/fGBjUWu 0AZuoSN+SCQoMhlQRjOQdhZvgm4uaY+ZfmAHbYb7op4lrW1Aa4uyB7EKfm//YdPB+pCW DaGC/1WxARl15JaaCsv38Wyqs4PyikJ4XDnX7NLZumV53LKfIvsUgYq3Y3wOGf/Om/Pf HxUIVFporDu1yCC4KSNh0mu1ORm3Ke2aY00z3Gau+QxHdJp57Gxp4pHp4CuivCcH+48Z jR7A== X-Forwarded-Encrypted: i=1; AJvYcCUIHna0geQxi+VoYcEFIE0c5LSXv+Sq/PEqUcR2R5F3hWSHPwM0oWOLMAlavSJisrcfVpXjwgBxCPBODZi4/JwO@lists.infradead.org X-Gm-Message-State: AOJu0YzV/Z/JhIgx1B9WXxnoAEkJhmBIcF4WD3nYqjtrRb/m9qPQy8N7 03x9jh4mOZQ566Ep+re/cB1dT5kUFn/OKuh5U8TCAXMqes652NfTz5Rd X-Gm-Gg: ATEYQzxoZe6Wi5YtNn5nPg31RagCDLaE9QQYImHKX7xoSkjgzoF44cC6JjEbQD4KnIu a8rFLPkX+J1v/i764UCUOgocdsoHwuNRiYWIRJTcHj3vVMjN0VgtkyfnnC3lNNH7LLEo+Jpx8Kx fjlkGZpM2w0cy6Fz+Z8hR2Xwdos/HTx9yBa+eFsMi5bbYAdWHAo+rlyRjxvC/qLt8kf3oglSHeI YjJJyn0sY0JANweqhMs3RHU529AAY2jMFlIDfHTowATDwjbA7lRZwHgj2OD2FNvjnJRjNmci6lt hBRtUPEa0yky7FEc8bJiq3R7RM0CuSSUL23nz1ERjrCdCl4CCPc3JN8ankOBCm55NJgEmixjUXC 3MI4JCDl9km6ysxlH49+31LiSLMElvkOLVr6NZ8IM2uSH/TOKadpt8NUPE6l/zItFgJi0ekiusY I3lzfB7n8EONsiSb/dgtZmcLf0qibE8+bRGUJOUuNE1OvZEZKCw32c0yD7r2u+4ElS X-Received: by 2002:a05:600c:3542:b0:480:1e8f:d15f with SMTP id 5b1f17b1804b1-483c9bc5596mr280473755e9.2.1772529134880; Tue, 03 Mar 2026 01:12:14 -0800 (PST) Received: from pumpkin (82-69-66-36.dsl.in-addr.zen.co.uk. [82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-48512692c14sm13045615e9.7.2026.03.03.01.12.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Mar 2026 01:12:14 -0800 (PST) Date: Tue, 3 Mar 2026 09:12:12 +0000 From: David Laight To: "Christophe Leroy (CS GROUP)" Cc: Alexander Viro , Andre Almeida , Andrew Cooper , Christian Borntraeger , Christian Brauner , Darren Hart , Davidlohr Bueso , Heiko Carstens , Jan Kara , Julia Lawall , Linus Torvalds , linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, LKML , Madhavan Srinivasan , Mathieu Desnoyers , Michael Ellerman , Nicholas Piggin , Nicolas Palix , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , Russell King , Sven Schnelle , Thomas Gleixner , x86@kernel.org, Kees Cook , akpm@linux-foundation.org Subject: Re: [PATCH v2 4/5] uaccess: Disable -Wshadow in __scoped_user_access() Message-ID: <20260303091212.620241c8@pumpkin> In-Reply-To: References: <20260302132755.1475451-1-david.laight.linux@gmail.com> <20260302132755.1475451-5-david.laight.linux@gmail.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260303_011217_595225_B68A3724 X-CRM114-Status: GOOD ( 14.87 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 2 Mar 2026 16:00:26 +0100 "Christophe Leroy (CS GROUP)" wrote: > Le 02/03/2026 =C3=A0 14:27, david.laight.linux@gmail.com a =C3=A9crit=C2= =A0: > > From: David Laight > >=20 > > -Wshadow is enabled by W=3D2 builds and __scoped_user_access() quite > > deliberately creates a 'const' shadow of the 'user' address that > > references a 'guard page' when the application passes a kernel pointer. > >=20 > > Signed-off-by: David Laight =20 >=20 > There is a problem with this patch: (badly line-wrapped errors deleted) It seems to need gcc 12. (So Linus is in luck.) Prior to gcc 12 the #pragma generated by _Pragma() act as the controlled statement of the for () loop. Trying to put the _Pragma() inside the for statement doesn't work at all. David