From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755381Ab1DZNJv (ORCPT ); Tue, 26 Apr 2011 09:09:51 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:36387 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753604Ab1DZNJt (ORCPT ); Tue, 26 Apr 2011 09:09:49 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=F2c5JFoJpEBg+frAxXOih49JrUtkUImAfPZoC5yCWmC007Yr97RAaDIcHNWfdhzkXn J+9jOOvu7ZFCoP5uzz/0W3zKLuqmUh+uf4neyeBYY0XIlUP9OfY9qEBo9oJue8DqiE8W Yc00F8G6u9ZqTaSt2KvRgmIej+u8ldxKDoS4s= Subject: Re: [BUG] perf and kmemcheck : fatal combination From: Eric Dumazet To: Peter Zijlstra Cc: Pekka Enberg , Ingo Molnar , Arnaldo Carvalho de Melo , Paul Mackerras , Vegard Nossum , linux-kernel , Mathieu Desnoyers In-Reply-To: <1303822603.3358.51.camel@edumazet-laptop> References: <1303747731.2747.182.camel@edumazet-laptop> <1303803525.20212.20.camel@twins> <20110426080443.GA806@elte.hu> <1303808257.3012.3.camel@edumazet-laptop> <1303811635.3358.21.camel@edumazet-laptop> <1303813668.3358.22.camel@edumazet-laptop> <1303820855.3358.49.camel@edumazet-laptop> <1303821188.20212.264.camel@twins> <1303822603.3358.51.camel@edumazet-laptop> Content-Type: text/plain; charset="UTF-8" Date: Tue, 26 Apr 2011 15:09:44 +0200 Message-ID: <1303823384.3358.53.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le mardi 26 avril 2011 à 14:56 +0200, Eric Dumazet a écrit : > Le mardi 26 avril 2011 à 14:33 +0200, Peter Zijlstra a écrit : > > On Tue, 2011-04-26 at 14:27 +0200, Eric Dumazet wrote: > > > Thats far from trivial, maybe because we dont have NOTRACK api for > > > percpu allocations ? > > > > We can't use per-cpu allocations from NMI context because of the same > > problem, per-cpu uses vmalloc and vmalloc needs faults. Hence that > > shouldn't be a problem. > > > > It looks like you covered most of it though, the buffer and the > > callchain stuff, aside from that it should only use some static data. > > > > Pekka, what does kmemcheck do for .data and .bss things? > > Hmm, maybe I have a problem because of the WARN_ON in kmemcheck and my > boot had "log_buf_len=32M", so kmemcheck was called again > > > I am now trying to remve the line 634 from > arch/x86/mm/kmemcheck/kmemcheck.c Yes, its making some progress [ 328.696312] BUG: unable to handle kernel [ 328.697078] kernel tried to execute NX-protected page - exploit attempt? (uid: 0) [ 328.698284] BUG: unable to handle kernel paging request at ffff88011fc07b58 [ 328.699569] IP: [] 0xffff88011fc07967 [ 328.700488] PGD 1a94063 PUD 11f6f9067 PMD 11f7f8067 PTE 800000011fc07163 [ 328.702327] Oops: 0011 [#1] PREEMPT SMP [ 328.703693] last sysfs file: /sys/devices/system/cpu/online [ 328.704361] CPU 0 [ 328.704777] Modules linked in: nfsd lockd auth_rpcgss sunrpc tg3 libphy sg [last unloaded: x_tables] [ 328.708693] [ 328.709075] Pid: 4019, comm: perf Not tainted 2.6.39-rc4-00369-g23cf772-dirty #562 HP ProLiant BL460c G6 [ 328.710581] RIP: 3c4c:[] [] 0xffff88011fc07967 [ 328.711692] RSP: 0000:ffff88011b3cbfd8 EFLAGS: ffff88011fc0793c [ 328.712388] RAX: ffff88011b3ca000 RBX: ffff88011fc07ff8 RCX: ffff88011fc07158 [ 328.713180] RDX: ffff88011fc03fc0 RSI: ffff88011fc00000 RDI: ffff88011fc07158 [ 328.713959] RBP: ffff88011fc07888 R08: ffffffff81601680 R09: ffff880114278400 [ 328.714738] R10: ffffffff81004ed3 R11: ffff88011fc078d8 R12: ffffffff8105eb99 [ 328.715516] R13: ffff88011fc07888 R14: 0000000000000018 R15: ffff880112638238 [ 328.716294] FS: 0000000000000000(0000) GS:ffff88011fc00000(0063) knlGS:00000000f77176c0