From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757126AbaE2J4M (ORCPT ); Thu, 29 May 2014 05:56:12 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:50783 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757006AbaE2J4L (ORCPT ); Thu, 29 May 2014 05:56:11 -0400 Message-ID: <53870433.8090606@hitachi.com> Date: Thu, 29 May 2014 18:56:03 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Arnaldo Carvalho de Melo Cc: Ingo Molnar , Paul Mackerras , Peter Zijlstra , Jiri Olsa , Linux Kernel Mailing List Subject: Re: [BUG] perf probe segfaulting when asked for variable it doesn't find References: <20140528214406.GE2764@kernel.org> In-Reply-To: <20140528214406.GE2764@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2014/05/29 6:44), Arnaldo Carvalho de Melo wrote: > Masami-san, > > While trying: > > [root@zoo ~]# perf probe 'vfs_getname=getname_flags:65 pathname=result->name:string' > Failed to find the location of result at this address. > Perhaps, it has been optimized out. > Failed to find 'result' in this function. > Error: Failed to add events. (-2) > [root@zoo ~]# perf probe 'vfs_getname=getname_flags:65 pathname=result->name:string' > Added new event: > Segmentation fault (core dumped) > > I got segfaulted while in the past I would get the much nicer: > > [root@zoo ~]# perf probe 'vfs_getname=getname_flags:65 pathname=result->name:string' > Failed to find the location of result at this address. > Perhaps, it has been optimized out. > Failed to find 'result' in this function. > Error: Failed to add events. (-2) > [root@zoo ~]# Oops, I got that. Bad SEGV was reproduced here too. And I've found an error-handling miss in the convert_variable(), I'll send a patch for fixing it. Thank you very much for bisecting and finding my fault. -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com