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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 28BE1C43381 for ; Mon, 8 Feb 2021 20:12:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDE2564E5D for ; Mon, 8 Feb 2021 20:12:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236730AbhBHUMs (ORCPT ); Mon, 8 Feb 2021 15:12:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235716AbhBHSkW (ORCPT ); Mon, 8 Feb 2021 13:40:22 -0500 Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1806C061788; Mon, 8 Feb 2021 10:39:40 -0800 (PST) Received: by mail-pg1-x52a.google.com with SMTP id c132so10804387pga.3; Mon, 08 Feb 2021 10:39:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=OXsP7etvkquZcgLN+0ZBxKek7pWgCF6Ku7uGUtKs97I=; b=icFUkUZSlauoM1BcKvcJzDZLoo8oo1wZ+HtBsaFkgDhDjF9+P3Oezy9+bt52sdLtV1 Zoz79tnmx+uRhxgw8ZGE3QqFsRiXTpcQkpN8Av/i+gUOsw8fBVMiiZ0WamTWJbPC4LwA wiT4CInCqo+OtLbwbAx4SnBXuSY12diFilkpepCOac5aUXh+tpgxnMl15asmx4j/nrNN SihUmP3RhZpWUzQHA873Vm3QvvP9oz2bb8+sNXNITu7+X2qFDFRDmV3xjiMTPnFAJ/7D Ui3M/Wbjv2XdZRTzHNqh90b0A3E2sq/EZ+UmIm48/9cH+MAXXRtVw87EI+UbAKQbwNYG /kKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=OXsP7etvkquZcgLN+0ZBxKek7pWgCF6Ku7uGUtKs97I=; b=V1VZgxjc5x+dfMDV2lfM9zZiCfOztIeUhK9AfQOYgvl6htb1+SDwWNvwpoaLby27AG A2uhe5K3otVWd9tjkIQhBdbcQz5S+fHWDE4V7IWZzFp2HJGkQadGpYipE7rR2YeHDK+o nNX2W+fE8LVdDx55v9KA9rZ40nLBl9LUxOiXmZK3QvT+hFvAALVA351UrX3UJKaTcW5u CSkaQkSINUAdMaJqjbSALX00nQ2HWpCNp9piF21Ks4JYiheNtvEgKh8feO4IjVNKvmhf lmaXShwxywBN3sDUC5BNGAsz9s+YHZ+97cheFM8AAzXbr4wuC7V+2QFCgmIgvPgkeNn2 gQmg== X-Gm-Message-State: AOAM533QcyxpmHWtRUzC1mAw7JHAHwdpTHJY8XrK3zFgP5CNXBxoR6wK ZHNXMUGaSeVsLYvktkHAuXE= X-Google-Smtp-Source: ABdhPJzZJmkotHvueFLxVOfrROL778amS3T+8zb8OezYdn81GGHSUROAUWugiwoa3hMKn176NcODwg== X-Received: by 2002:a65:44c5:: with SMTP id g5mr18523114pgs.295.1612809580033; Mon, 08 Feb 2021 10:39:40 -0800 (PST) Received: from gmail.com ([2601:600:9b7f:872e:a655:30fb:7373:c762]) by smtp.gmail.com with ESMTPSA id c23sm9222470pfi.47.2021.02.08.10.39.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Feb 2021 10:39:39 -0800 (PST) Date: Mon, 8 Feb 2021 10:37:52 -0800 From: Andrei Vagin To: Keno Fischer Cc: Will Deacon , Catalin Marinas , Oleg Nesterov , linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List , linux-api@vger.kernel.org, Anthony Steinhauser , Dave Martin , Kyle Huey , Robert O'Callahan Subject: Re: [PATCH 0/3 v2] arm64/ptrace: allow to get all registers on syscall traps Message-ID: <20210208183752.GB559391@gmail.com> References: <20210201194012.524831-1-avagin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 01, 2021 at 07:11:12PM -0500, Keno Fischer wrote: > Hi Andrei, > > > This series introduces the PTRACE_O_ARM64_RAW_REGS option. If it is set, > > PTRACE_GETREGSET returns values of all registers, and PTRACE_SETREGSET > > allows to change any of them. > > thanks for picking this up. I meant to work on this, but unfortunately ran out > of time to be able to push it through, so I'm glad you're working on > it, since it > does absolutely need to get fixed. Besides this issue, the other problem we > ran into when trying to port our ptracer to aarch64 is that orig_x0 is not > accessible through the ptrace interface on aarch64, which can cause tricky > behavior around restarts. Could you describe the problem in more details? I wonder whether we have the same thing in CRIU... > We managed to work around that in the end, > but it's painful. If we're fixing the kernel here anyway, I'm wondering if > we might want to address that as well while we're at it. Sure let think how to do this properly. In this case, I think the ptrace option isn't a good choise. I don't think that it is a good idea to change the layout of regset depending on options... Thanks, Andrei > > Keno