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 B9DBFCAC5A0 for ; Wed, 17 Sep 2025 17:14:38 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3ZnzYSDutUgh7o+CZnN+NC1YHS/1qR4hhMnn1z+BEVU=; b=2t9ANFioovpOH7QnKQLPbEgMOk eY6VEIENU+bJtf6ge0WalYc8TTyXY8NGz5d+67js866vnmFQ6n0Agy4K6COlo+sMoWJ+xVpsfWNua hRI86+yBWSSEH2DLIVTVT218Sw3fUcIx6zTQGXZh8Qh+W+dRChybljlmHQ9rBVwjacY45WMpf4HW6 djzDrMyWvEA4oOxQwPbODXGmrd4s44dOSUY6kzAX9Saf9E5P95plOdpDy/RSDfOJ6jpqi1xEPrnSM SI1zls6mqZENdLd/7Vd8nD3Bd+02XrWCuoaDCdcPTaH+SwWA9pByBO4PjfjSmB6nYCbWNZTq15kpF Kp8Ow/AQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uyvjk-0000000DTLE-3OtY; Wed, 17 Sep 2025 17:14:32 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uyvji-0000000DTJj-3rBB for linux-arm-kernel@lists.infradead.org; Wed, 17 Sep 2025 17:14:31 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 3391F40A54; Wed, 17 Sep 2025 17:14:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E28E4C4CEE7; Wed, 17 Sep 2025 17:14:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758129270; bh=tmdsQ+Xu5/oIWo6bRP1Mnp6X483CCjaQbZUxpCmtk14=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Z8mTjvDTIvoAMnydYGhJ7895qPxNZclTPIRFnuKmk7B9Sszb3v9rKYQ6nv1m3Ph8L HWydvAOhH4p0yh5ZfRbEcv/oVIRFdYrBKP1+0fUgyFRmC3qy1dAEvSisNGR4Wmmv+M 9yzivsDxdgXgurH8vgZjCSu+BZLIDP7lkFzRjjxICViHMqV/U2UBrweXvisOPHXsDg om3vG1FeYTiM3Y7FSF2z+KktBvNXABNqdNfObsAA7DcUlDQ3yQXYrK8pWQphTxKSbb M6goTtaWKHdh3QZPrsdcBFRPRI1D+Pnba4aZkXbeTnmtoO9aTyGfY+/Prr01xVdo/+ guQjLec6nE7Rg== Date: Wed, 17 Sep 2025 10:14:24 -0700 From: Nathan Chancellor To: "Russell King (Oracle)" Cc: Thomas Gleixner , LKML , Linus Torvalds , Peter Zijlstra , kernel test robot , linux-arm-kernel@lists.infradead.org, Christophe Leroy , Darren Hart , Davidlohr Bueso , =?iso-8859-1?Q?Andr=E9?= Almeida , x86@kernel.org, Alexander Viro , Christian Brauner , Jan Kara , linux-fsdevel@vger.kernel.org Subject: Re: [patch V2 1/6] ARM: uaccess: Implement missing __get_user_asm_dword() Message-ID: <20250917171424.GB1457869@ax162> References: <875xdhaaun.ffs@tglx> <87y0qd89q9.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250917_101430_976668_D40632C6 X-CRM114-Status: GOOD ( 10.03 ) 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 Wed, Sep 17, 2025 at 04:17:38PM +0100, Russell King (Oracle) wrote: > For me, this produces: > > get-user-test.c:41:16: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] > 41 | (x) = *(__force __typeof__(*(ptr)) *) &__gu_val; \ > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > with arm-linux-gnueabihf-gcc (Debian 14.2.0-19) 14.2.0 > > Maybe you're using a different compiler that doesn't issue that warning? Maybe because the kernel uses -fno-strict-aliasing, which presumably turns off -Wstrict-aliasing? Cheers, Nathan