Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757627Ab3EWOGL (ORCPT ); Thu, 23 May 2013 10:06:11 -0400 Received: from mail-vc0-f173.google.com ([209.85.220.173]:45828 "EHLO mail-vc0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757208Ab3EWOGJ (ORCPT ); Thu, 23 May 2013 10:06:09 -0400 Date: Thu, 23 May 2013 10:10:36 -0400 (EDT) From: Vince Weaver To: Peter Zijlstra cc: Al Viro , Vince Weaver , linux-kernel@vger.kernel.org, Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , trinity@vger.kernel.org Subject: Re: OOPS in perf_mmap_close() In-Reply-To: <20130523125218.GB23650@twins.programming.kicks-ass.net> Message-ID: References: <20130523044803.GA25399@ZenIV.linux.org.uk> <20130523125218.GB23650@twins.programming.kicks-ass.net> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 816 Lines: 25 I can confirm your patch avoids the oops on my machine. It does lead to interesting behavior if I run the sample program multiple times (with added printfs): vince@core2:~$ ./perf_mmap_close_bug mmap1=0x7f06a6e90000 mmap2=0x7f06a6e7f000 vince@core2:~$ ./perf_mmap_close_bug mmap1=0x7f878a138000 mmap2=0x7f878a127000 vince@core2:~$ ./perf_mmap_close_bug mmap1=0xffffffffffffffff Error opening fd2 Invalid argument and then it never successfully completes again. Is this unexpected behavior? Or just a normal mmap/perf interaction that I don't understand? Vince -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/