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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS 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 345D3C43381 for ; Thu, 28 Feb 2019 01:54:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F07E0218A2 for ; Thu, 28 Feb 2019 01:54:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551318878; bh=TbFE+6dMBZm1rzfX4E4Fz9qBFi4AtNbRwsBU+BvlPh8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=Y7RvIsO8IbzLhLmu/6++0MNMgUtlHKPG+dz6VjbEL/kf4H847t+ueiluQxz4J3MBK A5vbnM6eMGznaD0Xiayw8xHIlyctb6jY27Fh3bVii0HamBnANfKgHxdy3+veRCsbmP ZG/h5M60b77J7dxx3MWN+pYv9o50xWQimfMaEbFA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730704AbfB1Byg (ORCPT ); Wed, 27 Feb 2019 20:54:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:44156 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730240AbfB1Byg (ORCPT ); Wed, 27 Feb 2019 20:54:36 -0500 Received: from devbox (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 8FC6620863; Thu, 28 Feb 2019 01:54:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551318875; bh=TbFE+6dMBZm1rzfX4E4Fz9qBFi4AtNbRwsBU+BvlPh8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=E6q/bCVnTO6a1EbhEIbnhBZ3r00VMmN0WOhYFTE1RxKNsOVM/I8c1aoaux93CoE2q vp5g3vu9uYaDLWtJseOe3OB27wTUAmBg/gae0Vs34CKoa2yip3fhjUl6ey0uzyPisz 8zKr/Jlae1GDyBg30GO1ZY0KUJODm1sfzRqakFmQ= Date: Thu, 28 Feb 2019 10:54:31 +0900 From: Masami Hiramatsu To: Alexei Starovoitov Cc: Steven Rostedt , Linus Torvalds , linux-kernel@vger.kernel.org, Andy Lutomirski , Ingo Molnar , Andrew Morton , Changbin Du , Jann Horn , Kees Cook , Andy Lutomirski , Nadav Amit , Peter Zijlstra Subject: Re: [PATCH v3 0/5] tracing/probes: uaccess: Add support user-space access Message-Id: <20190228105431.ca1fbf6ae6fca15de2f17c22@kernel.org> In-Reply-To: <20190227223239.x42tnefzwpbpkq3t@ast-mbp> References: <155127853496.32576.3705994926675037747.stgit@devbox> <20190227223239.x42tnefzwpbpkq3t@ast-mbp> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 27 Feb 2019 14:32:41 -0800 Alexei Starovoitov wrote: > On Wed, Feb 27, 2019 at 11:42:15PM +0900, Masami Hiramatsu wrote: > > > > For perf-probe, we can add some attribute for each argument > > which indicate that the variable in user space. But still > > we can not decide it automatically by DWARF since __user attribute > > is not transrated to DWARF attribute. > > clang has partial support for __attribute__((noderef, address_space(1))) > We'll work on patches to make it complete and pass __user attribute > all the way to debug info. Great! That's what I need. Could you point where (or who) I should check the implementation? I guess it will add DW_AT_segment to variable instance, if so it is easy to support it in perf probe. > > If somebody can work with gcc folks to do the same that would be awesome. > Thank you, -- Masami Hiramatsu