From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751764AbaKCMvt (ORCPT ); Mon, 3 Nov 2014 07:51:49 -0500 Received: from terminus.zytor.com ([198.137.202.10]:49033 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751130AbaKCMvq (ORCPT ); Mon, 3 Nov 2014 07:51:46 -0500 Date: Mon, 3 Nov 2014 04:51:33 -0800 From: tip-bot for James Custer Message-ID: Cc: hpa@zytor.com, jcuster@sgi.com, tglx@linutronix.de, rja@sgi.com, mingo@kernel.org, linux-kernel@vger.kernel.org Reply-To: linux-kernel@vger.kernel.org, rja@sgi.com, mingo@kernel.org, tglx@linutronix.de, jcuster@sgi.com, hpa@zytor.com In-Reply-To: <1414952199-185319-2-git-send-email-jcuster@sgi.com> References: <1414952199-185319-2-git-send-email-jcuster@sgi.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/uv] x86: UV BAU: Avoid NULL pointer reference in ptc_seq_show Git-Commit-ID: fa2a79ce6aef5de35a4d50487da35deb6b634944 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: fa2a79ce6aef5de35a4d50487da35deb6b634944 Gitweb: http://git.kernel.org/tip/fa2a79ce6aef5de35a4d50487da35deb6b634944 Author: James Custer AuthorDate: Sun, 2 Nov 2014 12:16:39 -0600 Committer: Thomas Gleixner CommitDate: Mon, 3 Nov 2014 13:49:24 +0100 x86: UV BAU: Avoid NULL pointer reference in ptc_seq_show In init_per_cpu(), when get_cpu_topology() fails, init_per_cpu_tunables() is not called afterwards. This means that bau_control->statp is NULL. If a user then reads /proc/sgi_uv/ptc_statistics ptc_seq_show() references a NULL pointer. Therefore, since uv_bau_init calls set_bau_off when init_per_cpu() fails, we add code that detects when the bau is off in ptc_seq_show() to avoid referencing a NULL pointer. Signed-off-by: James Custer Cc: Russ Anderson Link: http://lkml.kernel.org/r/1414952199-185319-2-git-send-email-jcuster@sgi.com Signed-off-by: Thomas Gleixner --- arch/x86/platform/uv/tlb_uv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index 3968d67..570b1b1 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -1384,6 +1384,10 @@ static int ptc_seq_show(struct seq_file *file, void *data) } if (cpu < num_possible_cpus() && cpu_online(cpu)) { bcp = &per_cpu(bau_control, cpu); + if (bcp->nobau) { + seq_printf(file, "cpu %d bau disabled\n", cpu); + return 0; + } stat = bcp->statp; /* source side statistics */ seq_printf(file,