From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755422Ab0CCRzh (ORCPT ); Wed, 3 Mar 2010 12:55:37 -0500 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:45657 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755406Ab0CCRzf (ORCPT ); Wed, 3 Mar 2010 12:55:35 -0500 Date: Wed, 03 Mar 2010 09:55:53 -0800 (PST) Message-Id: <20100303.095553.105186917.davem@davemloft.net> To: eranian@google.com Cc: peterz@infradead.org, mingo@elte.hu, linux-kernel@vger.kernel.org, paulus@samba.org, robert.richter@amd.com, fweisbec@gmail.com Subject: Re: [RFC][PATCH 07/11] perf: Provide PERF_SAMPLE_REGS From: David Miller In-Reply-To: References: <1267637995.25158.96.camel@laptop> X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stephane Eranian Date: Wed, 3 Mar 2010 09:49:33 -0800 > On Wed, Mar 3, 2010 at 9:39 AM, Peter Zijlstra wrote: >> On Wed, 2010-03-03 at 09:30 -0800, Stephane Eranian wrote: >>> This assumes struct pt_regs is somehow exported to userland. >>> Is that the case? >> >> I seems to have understood they were, and asm/ptrace.h seems to agree >> with that, it has !__KERNEL__ definitions for struct pt_regs. >> > Seems to be the case, indeed. BTW, how are you going to cope with compat systems? If I build 'perf' on a sparc64 kernel build, it's going to get the 64-bit pt_regs. So I can't then use that binary on a sparc box running a 32-bit kernel. And vice versa. And more generally aren't we supposed to be able to eventually analyze perf dumps on any platform not just the one 'perf' was built under? We'll need to do something about the encoding of pt_regs, therefore.