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=-10.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 7B8ECC34047 for ; Tue, 18 Feb 2020 20:07:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4841722B48 for ; Tue, 18 Feb 2020 20:07:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qdFjDSdP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728281AbgBRT6q (ORCPT ); Tue, 18 Feb 2020 14:58:46 -0500 Received: from mail-ot1-f68.google.com ([209.85.210.68]:45543 "EHLO mail-ot1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726751AbgBRT6l (ORCPT ); Tue, 18 Feb 2020 14:58:41 -0500 Received: by mail-ot1-f68.google.com with SMTP id 59so20767945otp.12 for ; Tue, 18 Feb 2020 11:58:40 -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:user-agent; bh=UOjwYHMvf6TltZqdhvtIaC6UvMCiDEeSqOQKVNxR6Jw=; b=qdFjDSdPBN7d8V4wjLswZbCZ8j6D+/gzu7dsqRJj8R62FEIeH3CROCJtzhhme6sB8u CHGTzfOe+ZKEJELX/mWqA3iSFHkYKHCVOTRQz0X6CGiEelH0Zt/xuZLjHJTM6t6b0XL1 RJ41UEk5BtQVNBsUsOfqg6wndpZvhf4ZfZyXKN6oDPRvo5HIX8XSFLIN0B4m/JFhuo/6 i1kbC6P1sVaJVWepPrVOST7eGdLyyd8KUHic0KuA2Z304/N97cypZX+BqUcAyrT2Jd4j BNzE8o/FzkhOdoE4u2lvq1yINp5QOGqQKHWES5C+nlFQ4LkUxqaINpOzCF+fF4NKwFBD FuGA== 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:user-agent; bh=UOjwYHMvf6TltZqdhvtIaC6UvMCiDEeSqOQKVNxR6Jw=; b=CjO2WeZlCt0sXPhTC2lGi0mXUMwGlNglhQfb6A+X7RopTSjPSAGnPhe2z7VqxsIjX4 iYZQr9zEyK9OQg5eiRvBlc10wHCjXgzFpqeNsLxal3kri3TWkx3JbfTDzKbepbLoYVbv tTGjNK0NI2sgQ5j1IdjdWRFv7QdDkcoJCnzBqxKwB7nRZwplT6/NfW+IL9LQ+BK/RTny tDVfOFnqGnDZwdAp9hcKWmG8qXZ9DyNcGQOjqgYdUm/8+iFRXpFBjX4jagUCXFmeVMha Tw28CPQYmdaON1aZbV35Q16JF88jB/vH5XyM9a6TovehAbwJGCFZrOgbjE7BL0or3DkJ rKhQ== X-Gm-Message-State: APjAAAVaCNMOQBl+s5hD1JNiv7Ju6zv1zCeadsAEFrd1MK5GQTXOOIp0 91RgjGT2yalKRBBsRcmgGjM= X-Google-Smtp-Source: APXvYqzj1NAurGmfJwU5eZJRKQXu+5B/l1iUa0sbt6uTBSlPHsFQEhwNlpnYX38qDv9GVqEzftm84w== X-Received: by 2002:a05:6830:1d8b:: with SMTP id y11mr17774948oti.4.1582055920527; Tue, 18 Feb 2020 11:58:40 -0800 (PST) Received: from ubuntu-m2-xlarge-x86 ([2604:1380:4111:8b00::1]) by smtp.gmail.com with ESMTPSA id i20sm1687995otp.14.2020.02.18.11.58.39 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 18 Feb 2020 11:58:40 -0800 (PST) Date: Tue, 18 Feb 2020 12:58:38 -0700 From: Nathan Chancellor To: Josh Poimboeuf Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Nick Desaulniers Subject: Re: [PATCH 2/2] objtool: Improve call destination function detection Message-ID: <20200218195838.GA8061@ubuntu-m2-xlarge-x86> References: <0a7ee320bc0ea4469bd3dc450a7b4725669e0ea9.1581997059.git.jpoimboe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0a7ee320bc0ea4469bd3dc450a7b4725669e0ea9.1581997059.git.jpoimboe@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 17, 2020 at 09:41:54PM -0600, Josh Poimboeuf wrote: > A recent clang change, combined with a binutils bug, can trigger a > situation where a ".Lprintk$local" STT_NOTYPE symbol gets created at the > same offset as the "printk" STT_FUNC symbol. This confuses objtool: > > kernel/printk/printk.o: warning: objtool: ignore_loglevel_setup()+0x10: can't find call dest symbol at .text+0xc67 > > Improve the call destination detection by looking specifically for an > STT_FUNC symbol. > > Link: https://github.com/ClangBuiltLinux/linux/issues/872 > Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25551 > Reported-by: Nick Desaulniers > Signed-off-by: Josh Poimboeuf Tested with clang-11 and binutils 2.34, a combo that was previously broken and I no longer see these warnings on either defconfig or allyesconfig. Tested-by: Nathan Chancellor