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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F8FEC4332F for ; Tue, 2 Nov 2021 17:50:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A68B61058 for ; Tue, 2 Nov 2021 17:50:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232855AbhKBRxS (ORCPT ); Tue, 2 Nov 2021 13:53:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231137AbhKBRxQ (ORCPT ); Tue, 2 Nov 2021 13:53:16 -0400 Received: from mail-lf1-x129.google.com (mail-lf1-x129.google.com [IPv6:2a00:1450:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6142C061714 for ; Tue, 2 Nov 2021 10:50:41 -0700 (PDT) Received: by mail-lf1-x129.google.com with SMTP id bq11so168954lfb.10 for ; Tue, 02 Nov 2021 10:50:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Evjqo5x9nTSOUDyDFPn5FDtubzC/QO/xYkyrR/MU7Oc=; b=Kwy1ytoYq54MS/sS+JM7LrEQZYxzXLwsTaOhT+yG6ODxpfxYJvJDjPZJQxggwhvQjs 6o25zhDLZzQIsBnztTL4lbh9mOPtPVaFamnTA87r9F1w8GD8QJAKQn0NvrCT9Wfx9tu0 UdE7RcIwDlCsl6LAUFmlYSAPFKEFpQbbObMfs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Evjqo5x9nTSOUDyDFPn5FDtubzC/QO/xYkyrR/MU7Oc=; b=43LRMuJzPXjkIFrBNIOgTr1JajEhVimO6yv31qot/b5lm2VE7HjRuQVhMT/cepjvG7 Gct0OPQ7iqCXqabaI1oDeiowZr7nBye+MK1yaIaRUlqRmWYKeCOqCQB8uPdTudOqC+Bw Z080fRufIo6RlMqrw8mTCmrxm/GIL/iyJSmgBDArAYNSXj5p4kr9bdKNBSHfsKP88vDK 3xx74u8ruM/cMp4SdxAgfFMSxvgyff8ZEXwzv4vxc42Lm0GgF5HMjWSkm7ixesF2KDRS BkTQBvxPpa8OvekThQGe2weu6rP91QjfWw66Sq5rr+/olf2zjmTz9VCgJN2w77DnQWvt 5zAg== X-Gm-Message-State: AOAM532UiSptAnna+Gho+aBY7gMixSZY9l6qyQZRc3WRaKjoUHcYuj7w SrG/7fkYDQ1QBJkDEUrwrHJuCotT6owgyZuH X-Google-Smtp-Source: ABdhPJzIYVexB23FYasiGgRAV/9UsNpWUbH+NHDgOuuxGAS14J4m1XpcBuQIM/SzcoRrIB11A4TRVA== X-Received: by 2002:a19:384b:: with SMTP id d11mr6843853lfj.312.1635875439812; Tue, 02 Nov 2021 10:50:39 -0700 (PDT) Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com. [209.85.167.44]) by smtp.gmail.com with ESMTPSA id c15sm1739426lft.244.2021.11.02.10.50.38 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 02 Nov 2021 10:50:38 -0700 (PDT) Received: by mail-lf1-f44.google.com with SMTP id i3so231656lfu.4 for ; Tue, 02 Nov 2021 10:50:38 -0700 (PDT) X-Received: by 2002:a05:6512:3993:: with SMTP id j19mr33110123lfu.402.1635875438251; Tue, 02 Nov 2021 10:50:38 -0700 (PDT) MIME-Version: 1.0 References: <163572864256.3357115.931779940195622047.tglx@xen13> <163572864563.3357115.8793939214537874196.tglx@xen13> In-Reply-To: From: Linus Torvalds Date: Tue, 2 Nov 2021 10:50:06 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Stackleak vs noinstr (Was: [GIT pull] objtool/core for v5.16-rc1) To: Peter Zijlstra Cc: Thomas Gleixner , Josh Poimboeuf , Linux Kernel Mailing List , "the arch/x86 maintainers" , Alexander Popov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 2, 2021 at 3:05 AM Peter Zijlstra wrote: > > Having the plugin gate on section name seems a lot hacky, but given it's > already doing that, one more doesn't hurt. Looks sane to me. Some of the other warnings are just odd. Why is mce_setup() 'noinst'? I'm not seeing any reason for it, but maybe I'm just blind. That one complains about the memcpy() call. Of course, I suspect memcpy/memset might be better off noinstr anyway, exactly because they can happen for very regular C code (struct assignments etc). But mce_setup() doesn't really seem to have much reason to not be instrumented. Linus