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 X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 838AAC56202 for ; Mon, 23 Nov 2020 11:50:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3598F20756 for ; Mon, 23 Nov 2020 11:50:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729140AbgKWLtm (ORCPT ); Mon, 23 Nov 2020 06:49:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:54550 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728976AbgKWLtl (ORCPT ); Mon, 23 Nov 2020 06:49:41 -0500 Received: from gaia (unknown [95.146.230.165]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D018D20756; Mon, 23 Nov 2020 11:49:38 +0000 (UTC) Date: Mon, 23 Nov 2020 11:49:36 +0000 From: Catalin Marinas To: "Eric W. Biederman" Cc: Peter Collingbourne , Evgenii Stepanov , Kostya Serebryany , Vincenzo Frascino , Dave Martin , Will Deacon , Oleg Nesterov , "James E.J. Bottomley" , Linux ARM , Kevin Brodsky , Andrey Konovalov , linux-api@vger.kernel.org, Helge Deller , David Spickett Subject: Re: [PATCH v21 1/2] signal: define the SA_EXPOSE_TAGBITS bit in sa_flags Message-ID: <20201123114935.GD17833@gaia> References: <13cf24d00ebdd8e1f55caf1821c7c29d54100191.1605904350.git.pcc@google.com> <87h7pj1ulp.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87h7pj1ulp.fsf@x220.int.ebiederm.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Fri, Nov 20, 2020 at 05:22:58PM -0600, Eric W. Biederman wrote: > Peter Collingbourne writes: > > > Architectures that support address tagging, such as arm64, may want to > > expose fault address tag bits to the signal handler to help diagnose > > memory errors. However, these bits have not been previously set, > > and their presence may confuse unaware user applications. Therefore, > > introduce a SA_EXPOSE_TAGBITS flag bit in sa_flags that a signal > > handler may use to explicitly request that the bits are set. > > > > The generic signal handler APIs expect to receive tagged addresses. > > Architectures may specify how to untag addresses in the case where > > SA_EXPOSE_TAGBITS is clear by defining the arch_untagged_si_addr > > function. > > > > Signed-off-by: Peter Collingbourne > > Acked-by: "Eric W. Biederman" > > Link: https://linux-review.googlesource.com/id/I16dd0ed2081f091fce97be0190cb8caa874c26cb > > --- > > To be applied on top of: > > https://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git signal-for-v5.11 > > I have merged this first patch into signal-for-v5.11 and pushed > everything out to linux-next. Thank you Eric. Assuming this branch won't be rebased, I'll apply the arm64 changes on top (well, if you rebase it, just let me know so that we don't end up with duplicate commits in mainline). -- Catalin