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 4814BCA5FBE for ; Wed, 30 Sep 2026 07:48:58 +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-Transfer-Encoding:Content-Type:MIME-Version:References: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=W8oH1Fi/Ld5hAhuB1dTiEaQRtEACoBcCrfBpjFkiric=; b=eoE8mI18BnGB6L1uASqcpsl1Wx YaKCXVj6as3SgyfSfYE2V5XCWK9HwvPkQ+UTxa22qHeveITWPXmpzUJfWVhh/xNdJvHW4G2RcXCgq QQHB8S4uHCnKbfuSKDIKBR9GP4GX8tXacpIOnS8fk6JVoHFzGnOGehkJICTOa/WC59nEGCOup6Evg OY8QXna5j6JvV0Xw9go3h9DWqNR313TcCwalb8MGVzfnf4tj37r1T7PSc3C2wGNJ1Bn+qLK8nkbEF oEW7SiLAGtPu6bAQtidAILZ24Xe8ICyIE/2nxr/GekPwIv8I7YjBnGKgLbWY5yU0yw/KYM9RhcyFY A8qm4wrw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBp3b-00000005Kfc-2Mdr; Wed, 30 Sep 2026 07:48:51 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBp3Z-00000005Ket-1dWZ for linux-arm-kernel@lists.infradead.org; Wed, 30 Sep 2026 07:48:49 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id C03CA60236; Wed, 30 Sep 2026 07:48:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4E571F00893; Wed, 30 Sep 2026 07:48:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790754528; bh=W8oH1Fi/Ld5hAhuB1dTiEaQRtEACoBcCrfBpjFkiric=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=YuOJKYJq22XVYvSATU7UyMhkbwLBasyBFeHMOjwtF4d6iiPCiQohQwEXa4287dvTE /LsLoJNZT6G4y0MEFW2wCFiLd+hmFAZCYywN3p1MQnlATCPhgfLRK6SK1WZoUy6JgE k/uLTWT3sGu36vNsoy9IFpuUJmXD/6PqE6zKK7LPno/LxxuPN5kK9FugikBP/Q4z1Q hSOmzrNNlY2TMFGXNb1af8wK1hUDtpUFvoOKTakkunvcTXesBLjBY4GIaKBx4ZQlAx al4pFuQA9JBuTzanSrs/VFUO0gBJYVyrA1YYUvnNRi/M/nVgD1d+RaUr0dHqj5F5sd 31T/8Yfsu/P/A== Date: Wed, 30 Sep 2026 08:48:42 +0100 From: Will Deacon To: =?iso-8859-1?Q?Andr=E9?= Almeida Cc: Catalin Marinas , Billy Laws , Mark Rutland , Mark Brown , Ryan Houdek , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel-dev@igalia.com Subject: Re: [RFC PATCH v3 1/1] arch: arm64: Implement unaligned atomic emulation Message-ID: References: <20260930020138.2377090-1-andrealmeid@igalia.com> <20260930020138.2377090-2-andrealmeid@igalia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260930020138.2377090-2-andrealmeid@igalia.com> 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 Tue, Sep 29, 2026 at 11:01:38PM -0300, André Almeida wrote: > Implement support for emulating unaligned atomic operations on arm64. > User applications that wish to enable support for this should use the > pctrl() flag `PR_ARM64_UNALIGN_ATOMIC_EMULATE`. > > Signed-off-by: André Almeida > --- > arch/arm64/Kconfig | 6 + > arch/arm64/include/asm/exception.h | 1 + > arch/arm64/include/asm/processor.h | 5 + > arch/arm64/include/asm/rwonce.h | 14 +- > arch/arm64/include/asm/thread_info.h | 1 + > arch/arm64/kernel/Makefile | 3 +- > arch/arm64/kernel/process.c | 15 + > arch/arm64/kernel/unaligned_atomic.c | 521 +++++++++++++++++++++++++++ > arch/arm64/mm/fault.c | 10 + > include/uapi/linux/prctl.h | 5 + > kernel/sys.c | 7 +- > 11 files changed, 579 insertions(+), 9 deletions(-) > create mode 100644 arch/arm64/kernel/unaligned_atomic.c No. I already explained to you why this doesn't work: https://lore.kernel.org/r/aV1YnOetDHhKe4hz@willie-the-truck Will