From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49EouKYfmt22tUMUsn8u/naHheH3hZuA/5j8i5eo69KLN75oSTgAEdtSNrCL3wLPnGoDTff ARC-Seal: i=1; a=rsa-sha256; t=1523279659; cv=none; d=google.com; s=arc-20160816; b=IoqjU70+6qWkyowKkHc9PQm0olHk1YJdQFAe/pMKp3WoUyM5UDuY8McmYh+gJe99AI Snks81j2guLJ0qMX5f5OGRessN/aD9LsJQAdYzaHNxlnTKp7RJ3vRMuWqo7wVGNPZzHa 8XlsbBbO9E/TKgFFMmqX/xgdAbjD2orTXFKIbR38gPLO87tyJ3+ZkIS+cCWvFahQZcgj D3ffOmAgXltt0st9MqSRG4g0Sys/uLdLjVj5CB8YDqLVzeM7vw2WFWCwfECup0rPswa8 lGPd4TNgRMzzNiUOsYy6f77n8kV3gZ8fMTqHYlLxVdgeBT+pWJ7H2QDLmQFgolxlw/4K /hfQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:content-transfer-encoding:content-language :accept-language:in-reply-to:references:message-id:date:thread-index :thread-topic:subject:cc:to:from:delivered-to:list-id:list-subscribe :list-unsubscribe:list-help:list-post:precedence:mailing-list :arc-authentication-results; bh=2AUdWCIXsaanpDpWSP0+0Fy0EGXFfrEKCgM0GvXwSDo=; b=sTQ1Tw0fDRPJXIiJOJn5LNMGugd1SZaYyg+06KUezMxcUmn1Dq1t7J4WXqwc3duHLX 47Mij7oAcP2Tyeh4Kf9h41b5TJJTKqJ+ZIr70wOozzmzKpALWFQBsMeVBcu4uYCpdlPj ZU1ow6Gyru5DDipwo8/CoRlHO5ih/27lTkNMYyvYc/v75f4BNTPMIV8BbgOZyWiZmA6D BYeq4VaPYDwlFYbO9j4tQdj8GfgO5tE/HHN6DfuwjfaI6seBLljEoZT6vemvhy8zR6XD oMCfjU+c2+RW+UJqHpmfDKS8if3K9aF7MdUDiMqVPK9tcqQBxm5LW3DZnn97p8UTLeNi pL+g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12916-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12916-gregkh=linuxfoundation.org@lists.openwall.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12916-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12916-gregkh=linuxfoundation.org@lists.openwall.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: From: David Laight To: "'kpark3469@gmail.com'" , "kernel-hardening@lists.openwall.com" CC: "catalin.marinas@arm.com" , "keescook@chromium.org" , "will.deacon@arm.com" , "mark.rutland@arm.com" , "james.morse@arm.com" , "panand@redhat.com" , "keun-o.park@darkmatter.ae" , "psodagud@codeaurora.org" , "jpoimboe@redhat.com" , "mingo@kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH v3 3/3] x86: usercopy: reimplement arch_within_stack_frames with unwinder Thread-Topic: [PATCH v3 3/3] x86: usercopy: reimplement arch_within_stack_frames with unwinder Thread-Index: AQHTz/sSAuKS/MpI00yCw1px+eBQn6P4ZtyQ Date: Mon, 9 Apr 2018 13:14:58 +0000 Message-ID: References: <1523275156-29087-1-git-send-email-kpark3469@gmail.com> <1523275156-29087-2-git-send-email-kpark3469@gmail.com> <1523275156-29087-3-git-send-email-kpark3469@gmail.com> <1523275156-29087-4-git-send-email-kpark3469@gmail.com> In-Reply-To: <1523275156-29087-4-git-send-email-kpark3469@gmail.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.33] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-Outbound-IP: 156.67.243.126 X-Env-From: David.Laight@ACULAB.COM X-Proto: esmtps X-Revdns: X-HELO: AcuMS.aculab.com X-TLS: TLSv1.2:ECDHE-RSA-AES256-SHA384:256 X-Authenticated_ID: X-PolicySMART: 3396946, 3397078 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593731067679840173?= X-GMAIL-MSGID: =?utf-8?q?1597274492326962702?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: kpark3469@gmail.com > Sent: 09 April 2018 12:59 > > The old arch_within_stack_frames which used the frame pointer is > now reimplemented to use frame pointer unwinder apis. So the main > functionality is same as before. How much slower does this make the code? Following stack frames using %bp is reasonably quick. I can't imagine some of the other unwinder APIs being any where near that fast. While fine for fault tracebacks, using them during usercopy is likely to have measurable performance impact. David