Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752161AbaB1OXo (ORCPT ); Fri, 28 Feb 2014 09:23:44 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.228]:31411 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751532AbaB1OXn (ORCPT ); Fri, 28 Feb 2014 09:23:43 -0500 Date: Fri, 28 Feb 2014 09:23:41 -0500 From: Steven Rostedt To: Vince Weaver Cc: "H. Peter Anvin" , Peter Zijlstra , Linux Kernel , Ingo Molnar Subject: Re: perf_fuzzer compiled for x32 causes reboot Message-ID: <20140228092341.12a40f7c@gandalf.local.home> In-Reply-To: References: <530B90A5.3090302@zytor.com> <20140224141329.1cd3bb52@gandalf.local.home> <20140224193043.GP6835@laptop.programming.kicks-ass.net> <530C12CA.6070308@zytor.com> <20140225094352.73e0e28c@gandalf.local.home> <20140227173150.4e5ed747@gandalf.local.home> <530FC1C6.5040209@zytor.com> <20140227215726.7018c861@gandalf.local.home> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 28 Feb 2014 09:15:33 -0500 (EST) Vince Weaver wrote: > On Thu, 27 Feb 2014, Steven Rostedt wrote: > > > On Thu, 27 Feb 2014 20:34:34 -0500 (EST) > > Vince Weaver wrote: > > > > > > > > I would actually suggest we do the equivalent on i386 as well. > > > > > > > > Vince, could you try this patch as an experiment? > > > > > > OK with your patch applied it does not segfault. > > > > > > > Vince, Great! Can you remove Peter's patch, and try this one. It > > removes the crud to save the cr2 from entry_64.S and makes both i386 > > and x86_64 do the same thing in regards to cr2 handling. > > no, with only this patch applied it segfaults as per previous: > > [ 126.396049] perf_fuzzer[2904]: segfault at 17a0 ip 00000000004017fd sp 00000000ffaff3f0 error 6 in perf_fuzzer[400000+d1000] Interesting. Are you doing a perf function trace? And just in case, can you add this patch and make sure the copy is called by NMI. -- Steve diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index ddf9ecb..ca943cd 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -29,6 +29,7 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) */ pagefault_disable(); ret = __copy_from_user_inatomic(to, from, n); + trace_dump_stack(2) pagefault_enable(); return ret; -- 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/