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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4CCCEC02198 for ; Wed, 12 Feb 2025 17:18:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A7ABF6B0082; Wed, 12 Feb 2025 12:18:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A2AD86B0083; Wed, 12 Feb 2025 12:18:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8F2836B0085; Wed, 12 Feb 2025 12:18:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 724AF6B0082 for ; Wed, 12 Feb 2025 12:18:32 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 16F6E8011A for ; Wed, 12 Feb 2025 17:18:32 +0000 (UTC) X-FDA: 83111951664.08.555A9FD Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf01.hostedemail.com (Postfix) with ESMTP id 75F4840010 for ; Wed, 12 Feb 2025 17:18:30 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of cmarinas@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1739380710; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Rlgz5seG82Ux+fkG2i/legtN8SP4dQp1hc1HwNMZJ+Y=; b=R7xoVZjpGdll0WR3HthHGAI0XJa/UzBzLN4ux4HwkO1kRswdPVilhAvUlyKDprRh0f/4rt kB0DDbZ7YBir1mSdCuh9ELiCsYnJ6lOnG2J1BVK61Mdv+CdvDDk7CFDgqFoqNghEtcjYea NADMM5FzxBgjbDFwbE9JxegUcRuG7UA= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of cmarinas@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1739380710; a=rsa-sha256; cv=none; b=SoUd4OFH6JMMT5HG7qWw9aF2SNQjhnbCCNFwXw6XFmM/+FF6BYkAqXwrEIQ1uJVi/Hx1fX 7pjTMk6NLISpeC2SilnAWY29kc91VuIwgCBDUw6QU4Ctca++Zj5xs3t++dxQwqytHLGbz9 pA7opN9C4Hdol8AiM4Sg0SgkEJeTBg4= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id A6A1D5C5FFC; Wed, 12 Feb 2025 17:17:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D15C2C4CEDF; Wed, 12 Feb 2025 17:18:23 +0000 (UTC) Date: Wed, 12 Feb 2025 17:18:21 +0000 From: Catalin Marinas To: Tong Tiangen Cc: Mark Rutland , Jonathan Cameron , Mauro Carvalho Chehab , Will Deacon , Andrew Morton , James Morse , Robin Murphy , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Michael Ellerman , Nicholas Piggin , Andrey Ryabinin , Alexander Potapenko , Christophe Leroy , "Aneesh Kumar K.V" , "Naveen N. Rao" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Madhavan Srinivasan , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, wangkefeng.wang@huawei.com, Guohanjun Subject: Re: [PATCH v13 5/5] arm64: introduce copy_mc_to_kernel() implementation Message-ID: References: <20241209024257.3618492-1-tongtiangen@huawei.com> <20241209024257.3618492-6-tongtiangen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241209024257.3618492-6-tongtiangen@huawei.com> X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 75F4840010 X-Stat-Signature: mtwjjy6kudojh34zrma9xx7kpuyrd45f X-HE-Tag: 1739380710-915468 X-HE-Meta: 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 Ak2ysEMU 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Dec 09, 2024 at 10:42:57AM +0800, Tong Tiangen wrote: > The copy_mc_to_kernel() helper is memory copy implementation that handles > source exceptions. It can be used in memory copy scenarios that tolerate > hardware memory errors(e.g: pmem_read/dax_copy_to_iter). > > Currently, only x86 and ppc support this helper, Add this for ARM64 as > well, if ARCH_HAS_COPY_MC is defined, by implementing copy_mc_to_kernel() > and memcpy_mc() functions. > > Because there is no caller-saved GPR is available for saving "bytes not > copied" in memcpy(), the memcpy_mc() is referenced to the implementation > of copy_from_user(). In addition, the fixup of MOPS insn is not considered > at present. Same question as on the previous patch, can we not avoid the memcpy() duplication if the only difference is entries in the exception table? IIUC in patch 2 fixup_exception() even ignores the new type. The error must come on the do_sea() path. -- Catalin