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 60BD9C636CC for ; Tue, 31 Jan 2023 12:52:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To: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=12CX0ANpKSwfrBNcPM36wXzdXTptqzVYKCuiHV1flqo=; b=2qFmRaZj+cleD+ m7KzC8E7IgLB0tTYHng/Ja4LoG4EJUqF94onOYrCtW0YeUsXOBNZCyetyFapm49htxSVkPHKDKgH4 2fBRL3+BJD6T56cekdZ722xhr5X3OcgPa3YQftKr3vn2Cw462hW+BY6ibrOrQCH+10SiiFJG5BBhF DAU0a7JzbdrloejkckWUnOXtiunknEO2PNtFLz58OBQfYtYNSQB1vMMRBxJw6O16e3yicIrBmCUkF 45ecUqv7p5iAxuiCJ7TzWfoQT/0J/MCX3jZM8M8LHHaHTBLoRsvrtXmCbPETLUmPjkWh1UNE7jT5x W02cuGoMyigi1X3JqqXw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMq70-007uuC-54; Tue, 31 Jan 2023 12:51:46 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pMq6t-007urI-2M for linux-arm-kernel@lists.infradead.org; Tue, 31 Jan 2023 12:51:43 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5D180614E5 for ; Tue, 31 Jan 2023 12:51:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC4B3C433D2; Tue, 31 Jan 2023 12:51:36 +0000 (UTC) Date: Tue, 31 Jan 2023 12:51:33 +0000 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/6] arm64/signal: Signal handling cleanups Message-ID: References: <20221212-arm64-signal-cleanup-v2-0-14a8f3e088b7@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221212-arm64-signal-cleanup-v2-0-14a8f3e088b7@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230131_045141_803495_5E5F703F X-CRM114-Status: GOOD ( 16.61 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Mark, On Tue, Jan 03, 2023 at 08:25:15PM +0000, Mark Brown wrote: > This series collects a number of small cleanups to the signal handling > code which removes redundant validation of size information and avoids > reading the same data from userspace twice. > > There are some overlaps with both the TPIDR2 signal handling and SME2 > serieses which are also in flight, applying this will require > adjustments in those serieses and vice versa. [...] > Mark Brown (6): > arm64/signal: Don't redundantly verify FPSIMD magic > arm64/signal: Remove redundant size validation from parse_user_sigframe() > arm64/signal: Make interface for restore_fpsimd_context() consistent I'm fine with the first three patches, they seem correct and make the frame checking more consistent. > arm64/signal: Avoid rereading context frame sizes > arm64/signal: Only read new data when parsing the SVE context > arm64/signal: Only read new data when parsing the ZA context I'm not sure these add much to the code readability (and the performance improvement I guess is negligible). We avoid some copy_from_user() into the context structures but rely on data read previously or some get_user() into local variables. Personally I'd make the restore_fpsimd_context() also do a copy_from_user() for consistency with the current sve and za frames restoring. Personal preference, not sure whether Will has the same view. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel