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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 37DEDC433E2 for ; Wed, 22 Jul 2020 18:07:44 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 8DC88207DD for ; Wed, 22 Jul 2020 18:07:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="VQOOnqg7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DC88207DD Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-19413-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 32700 invoked by uid 550); 22 Jul 2020 18:07:37 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 32678 invoked from network); 22 Jul 2020 18:07:37 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=FdyJ3zCjPfmLPOxt0EpbJoGI3z0Dst2ftnMjMBs721s=; b=VQOOnqg73U7x3eQrsDW5P6NHQpsRTrBV6mDqQ35Y7KbR5dxMVHVEhlOpBKgbC4YauI hKoPoQogS3yVaVz+cHKlmtCp41T1+KI57s1dNmREFvPgWO9LQa1Md2XUbvuoYp7xcDOD uJkxpr/ugST6O4YCQmPPrAz4f1LYvrnmu4TBkKKzuhd7zdw95+t6HeiJXKW9A6c8pPUy XRNlbkclQcCrxbPIAZrisC31UWn7W4GKg1hOvR+OFZqdAhucXRldSHGUkEO+NbUB9S9S XaVu2nmp3aY/+8g9/c/Kskh84nH4FtiosOyHuJCZKQY+DsufHyQlBrv/tBuyO6TpzdFa UM+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=FdyJ3zCjPfmLPOxt0EpbJoGI3z0Dst2ftnMjMBs721s=; b=s9DS7kXq/T+fZJnPLruoVEi3i/ZfCfNEl3HJ8X3vseY6SCC/06O4OG28XTUHTTXCJV HAbmt/FKvBHiPgsc1VqiO++GZr2/YuIPeq+JXgZm/PU12Cp//DzZsLAEgZAvw1Bw3iSA lley8pFl+8e0SwnwEDLZ/0yATbevh4tI5Mw2/8A2qBBFUxoJEZUPLZ6JRcBLowQIf9RB DzLyFi7CZwayXVV5s8hZzuPJ+LCIY4/pBxftmcD8kr/wsjlCoInOilt47Ys/jShVWI1H HiMBrd4WqG3wLlgbB3iCts6y9A3GnB/7KGENNppo0XjkrZYE7DoqxNaxLfazXkB3P/4/ VSJw== X-Gm-Message-State: AOAM5303xYsrGN6hDDUa27kpK6vnI73DQdP9CzsIQSlLGXBDDdOL98t/ UTFbMtLejHrnYR9YrgpkiQ0GaPZzzqt0sZTIxGf8ww== X-Google-Smtp-Source: ABdhPJwcnL9bpNsR0ioOLFXQ9M3j8q0lz48Fhhhje9z+wnEe4/R/foPMYkXV+6IoYiAKnIEt8CMey3jrAzyf6UdUmaI= X-Received: by 2002:a05:6402:542:: with SMTP id i2mr682149edx.318.1595441245286; Wed, 22 Jul 2020 11:07:25 -0700 (PDT) MIME-Version: 1.0 References: <20200624203200.78870-1-samitolvanen@google.com> <20200624203200.78870-5-samitolvanen@google.com> <20200624212737.GV4817@hirez.programming.kicks-ass.net> <20200624214530.GA120457@google.com> <20200625074530.GW4817@hirez.programming.kicks-ass.net> <20200625161503.GB173089@google.com> <20200625200235.GQ4781@hirez.programming.kicks-ass.net> <20200625224042.GA169781@google.com> <20200626112931.GF4817@hirez.programming.kicks-ass.net> <20200717133645.7816c0b6@oasis.local.home> <20200717140545.6f008208@oasis.local.home> <20200722135829.7ca6fbc5@oasis.local.home> In-Reply-To: <20200722135829.7ca6fbc5@oasis.local.home> From: Sami Tolvanen Date: Wed, 22 Jul 2020 11:07:13 -0700 Message-ID: Subject: Re: [RFC][PATCH] objtool,x86_64: Replace recordmcount with objtool To: Steven Rostedt Cc: Peter Zijlstra , Masahiro Yamada , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , clang-built-linux , Kernel Hardening , linux-arch , linux-arm-kernel , linux-kbuild , LKML , linux-pci@vger.kernel.org, X86 ML , Josh Poimboeuf Content-Type: text/plain; charset="UTF-8" On Wed, Jul 22, 2020 at 10:58 AM Steven Rostedt wrote: > > On Mon, 20 Jul 2020 09:52:37 -0700 > Sami Tolvanen wrote: > > > > Does x86 have a way to differentiate between the two that record mcount > > > can check? > > > > I'm not sure if looking at the relocation alone is sufficient on x86, > > we might also have to decode the instruction, which is what objtool > > does. Did you have any thoughts on Peter's patch, or my initial > > suggestion, which adds a __nomcount attribute to affected functions? > > There's a lot of code in this thread. Can you give me the message-id of > Peter's patch in question. Sure, I was referring to the objtool patch in this message: https://lore.kernel.org/lkml/20200625200235.GQ4781@hirez.programming.kicks-ass.net/ Sami