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 7B3C4C433FE for ; Wed, 20 Apr 2022 07:33:37 +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:MIME-Version:In-Reply-To:References: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=oai5mnpZ7gSlNuO5ywJslAeIyG1yYqKx7QTe5ffpq88=; b=h18Tpp0b816+x6 Bd8QLKgo18KXbNZke0aagMT3J1Ez0twxLqPuZZ2Mb9mFOHOHW4HyJRpR+CcRxZX5bqriBEz8cQaf4 xVGF8EpgFty9Dj3lIWDEl2jqRki6DVBpUEEeGoM0EK5lMxZTepYOrZ3kU03WcileboG1rpf8SUGh6 rVbgPZPp6SrVZ1s+94lpk8Cob3ktS12E0ybQbYs19P2iR4gcEi89ckVZU3YMN3prY5uoW/lIXbBuy J4cAPkJL5qd1gQA3gOk8DhbVukjm+N6sZSx1cKluQ9wqatWHHqgvQh+jZzbSZBeVwinuGwMLhvzPm 8ichUryPhWo1r0tOmZGw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nh4pM-007msd-Ds; Wed, 20 Apr 2022 07:32:40 +0000 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nh4os-007mcJ-Gf for linux-arm-kernel@lists.infradead.org; Wed, 20 Apr 2022 07:32:12 +0000 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-165-jcx-0iaIPGatONrL5yGJ_Q-1; Wed, 20 Apr 2022 08:32:04 +0100 X-MC-Unique: jcx-0iaIPGatONrL5yGJ_Q-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.32; Wed, 20 Apr 2022 08:32:02 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.033; Wed, 20 Apr 2022 08:32:02 +0100 From: David Laight To: 'He Zhe' , Kees Cook CC: "catalin.marinas@arm.com" , "will@kernel.org" , "mark.rutland@arm.com" , "tglx@linutronix.de" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "alexander.shishkin@linux.intel.com" , "jolsa@kernel.org" , "namhyung@kernel.org" , "benh@kernel.crashing.org" , "paulus@samba.org" , "borntraeger@linux.ibm.com" , "svens@linux.ibm.com" , "hpa@zytor.com" , "x86@kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-riscv@lists.infradead.org" , "linux-s390@vger.kernel.org" , "linux-perf-users@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH RFC 2/8] arm64: stacktrace: Add arch_within_stack_frames Thread-Topic: [PATCH RFC 2/8] arm64: stacktrace: Add arch_within_stack_frames Thread-Index: AQHYU/YpuaYuTiSSXEqj2VkDLnuG5qz4aD5A Date: Wed, 20 Apr 2022 07:32:01 +0000 Message-ID: <9e5c394e82ec44e1887ebebe777a97f2@AcuMS.aculab.com> References: <20220418132217.1573072-1-zhe.he@windriver.com> <20220418132217.1573072-3-zhe.he@windriver.com> <202204181457.9DE190CE@keescook> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220420_003210_875597_E47C011E X-CRM114-Status: UNSURE ( 9.11 ) X-CRM114-Notice: Please train this message. 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 > > Thanks for doing this implementation! One reason usercopy hardening > > didn't persue doing a "full" stacktrace was because it seemed relatively > > expensive. Did you do any usercopy-heavily workload testing to see if > > there was a noticeable performance impact? Look at anything that uses sendmsg(). It is noticeably more expensive than sendto(). All the extra copy_from_user() cause measurable slow slowdowns. Using __copy_from_user()(to avoid 'hardending') in the socket code and when reading the iov[] gives a measurable improvement. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel