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 D1A16C63697 for ; Mon, 23 Nov 2020 18:54:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 763BE20729 for ; Mon, 23 Nov 2020 18:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730928AbgKWSyC (ORCPT ); Mon, 23 Nov 2020 13:54:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:47912 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729298AbgKWSyB (ORCPT ); Mon, 23 Nov 2020 13:54:01 -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 885B720657; Mon, 23 Nov 2020 18:53:58 +0000 (UTC) Date: Mon, 23 Nov 2020 18:53:55 +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: <20201123185355.GC2438@gaia> References: <13cf24d00ebdd8e1f55caf1821c7c29d54100191.1605904350.git.pcc@google.com> <87h7pj1ulp.fsf@x220.int.ebiederm.org> <20201123114935.GD17833@gaia> <87y2isysra.fsf@x220.int.ebiederm.org> <20201123155946.GA2438@gaia> <87sg90xd2n.fsf@x220.int.ebiederm.org> <20201123162329.GB2438@gaia> <87mtz8x9o5.fsf@x220.int.ebiederm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87mtz8x9o5.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 Mon, Nov 23, 2020 at 11:30:50AM -0600, Eric W. Biederman wrote: > Catalin Marinas writes: > > On Mon, Nov 23, 2020 at 10:17:20AM -0600, Eric W. Biederman wrote: > >> Catalin Marinas writes: > >> > On Mon, Nov 23, 2020 at 09:53:13AM -0600, Eric W. Biederman wrote: > >> >> Catalin Marinas writes: > >> >> > 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). > >> >> > >> >> No. I won't be rebasing it. Not unless something serious problem shows > >> >> up, and at that point I will be more likely to apply a corrective change > >> >> on top that you can also grab. > >> > > >> > Thanks Eric. During the merging window, I'll probably wait for you to > >> > send the pull request first just to keep the arm64 diffstat simpler. > >> > > >> > BTW, did you mean to base them on v5.10-rc3-391-g9cfd9c45994b or just > >> > v5.10-rc3? It doesn't matter much as I'll generate the diffstat manually > >> > anyway in my pull request as I have different bases in other branches. > >> > >> Crap. How did that happen? I thought for certain I had based them on > >> v5.10-rc3. Some random git commit is not a good base. I think the > >> better part of valor is to just admit I goofed and not rebase even now. > >> > >> It it would make your life easier I will be happy to rebase (onto > >> v5.10-rc3?). I just wanted to get these into my tree so that we could > >> incremetnally commit to the changes that makes sense and be certain not > >> to loose them. > > > > Please rebase onto -rc3 if there's not much hassle. > > Done. Thanks. -- Catalin