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 1475CCA5FB1 for ; Wed, 30 Sep 2026 11:58:38 +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:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=2cSTnnYtXnI4f0/RxiMP0j8RqZugNSFCAZhfvF0LPeU=; b=ejH4uytkM0uYpNNSgL/azq5zH5 VWoKE/Hm5j9UhWpQc0ZHT5aC3g5V8vlypYRCM2jkBEygIErlVxdbh078SvIr1AQLyqpD2BO+MUXXD z93E+MugVCWoo+pxfLUnrfSydhiTijJ91Dc3OlbfLzO0LoOVYbUYc1eyD86SGaJM1H3ZoAe82xZrO ubifiOTxQd92/woM9pS8rB2Ksjai79UWZpi9Xgb8IyJVKvJDcQU6LOsYXZjdOGlQu+muGW4eab6W8 nanC1MBslWRf/aNwn8crzEfYE/GDgJwnw6C7+Z9bHVmc1cLIS5gDveCQQF9d/6pgzcAUkHyfDtJJP dQiYaLEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBrZD-00000005lJ8-3xb7; Wed, 30 Sep 2026 10:29:39 +0000 Received: from fanzine2.igalia.com ([213.97.179.56]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xBrZA-00000005lIh-3erX for linux-arm-kernel@lists.infradead.org; Wed, 30 Sep 2026 10:29:38 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:From:Cc:To:Subject: MIME-Version:Date:Message-ID:From:Reply-To; bh=2cSTnnYtXnI4f0/RxiMP0j8RqZugNSFCAZhfvF0LPeU=; b=LDRnzcOTu7sQkXXxx/hW/Rgdsl MB8t7ZeZwYpOBXW1ZNlD7sE/E57HSv6hJ+FiFEB+EBDwoO2slvsBLkeHMeODUMRBifvjI2o92O5hf HboYLErQKlUTsEIiYG4Hoa1pLqgJJzBcpTBlzWyQmr39NlZDmxrSWMGQ5/YYmeZ4ir12PqyqrC0Ug X3Cnan2BytuIQGCbwfp4FRHNA3p6wtgCL56FyrrNAGboZbdi7N74ob1+CB05Us6Pcdxu7fMgkDBSx frN0C71zzGRDG+JX27+44ZF74nE4DjLafWj+fDZgRkBFwTcWOOsIkNj2Tn2E43CfWxwtO0A4M2SIQ rVhDA0pg==; Received: from [177.172.123.214] (helo=[192.168.15.100]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1xBrZ1-009Nib-Mz; Wed, 30 Sep 2026 12:29:27 +0200 Message-ID: <00227dc1-e01c-4de8-b3e3-3cd8de74cba9@igalia.com> Date: Wed, 30 Sep 2026 07:29:22 -0300 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH v3 1/1] arch: arm64: Implement unaligned atomic emulation To: Will Deacon 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 References: <20260930020138.2377090-1-andrealmeid@igalia.com> <20260930020138.2377090-2-andrealmeid@igalia.com> Content-Language: en-US From: =?UTF-8?Q?Andr=C3=A9_Almeida?= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260930_032937_223801_534161C4 X-CRM114-Status: GOOD ( 12.08 ) 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 Hi Will, thanks for the quickly reply, Em 30/09/2026 04:48, Will Deacon escreveu: > 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 Indeed, last time you raised some points, and then Ryan replied them. Is there any specific point that doesn't work? I couldn't find a reply for Ryan's answers: https://lore.kernel.org/all/CABnRqDf5EQUoXu=pJ6mj4-JfwAzEfcAE2cYrNzJANFycx7cMUA@mail.gmail.com/ > > Will