From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754273AbdAROiL (ORCPT ); Wed, 18 Jan 2017 09:38:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:57178 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754236AbdAROiJ (ORCPT ); Wed, 18 Jan 2017 09:38:09 -0500 Message-ID: <587F7DCF.70800@redhat.com> Date: Wed, 18 Jan 2017 09:38:07 -0500 From: Prarit Bhargava User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Greg Kroah-Hartman , linux-kernel@vger.kernel.org CC: stable@vger.kernel.org, Alexander Shishkin , Arnaldo Carvalho de Melo , Borislav Petkov , "H. Peter Anvin" , Harish Chegondi , Jiri Olsa , Kan Liang , Linus Torvalds , Peter Zijlstra , Stephane Eranian , Thomas Gleixner , Vince Weaver , Ingo Molnar Subject: Re: [PATCH 4.9 033/120] perf/x86/intel/uncore: Fix hardcoded socket 0 assumption in the Haswell init code References: <20170118104648.120216880@linuxfoundation.org> <20170118104649.461809044@linuxfoundation.org> In-Reply-To: <20170118104649.461809044@linuxfoundation.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 18 Jan 2017 14:38:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/18/2017 05:45 AM, Greg Kroah-Hartman wrote: > 4.9-stable review patch. If anyone has any objections, please let me know. > Nack. The value of boot_cpu_data.logical_proc_id may be uninitialized and set to default -1 on systems that pick a random core as boot cpu. This was inadvertently fixed by 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust") which is in 4.10-rc1. Before 9d85eb9119f4: [ 3.971539] hswep_uncore_cpu_init: cpu 5 pkg 0 boot_cpu_data.logical_proc_id 65535 [ 3.976504] hswep_uncore_cpu_init: cpu 5 pkg 0 cpu_data(0).logical_proc_id 0 After 9d85eb9119f4: [ 3.919112] hswep_uncore_cpu_init: cpu 5 pkg 0 boot_cpu_data.logical_proc_id 0 [ 3.923391] hswep_uncore_cpu_init: cpu 5 pkg 0 cpu_data(0).logical_proc_id 0 This patch should not be applied to any stable branch. P. > ------------------ > > From: Prarit Bhargava > > commit 6d6daa20945f3f598e56e18d1f926c08754f5801 upstream. > > hswep_uncore_cpu_init() uses a hardcoded physical package id 0 for the boot > cpu. This works as long as the boot CPU is actually on the physical package > 0, which is normaly the case after power on / reboot. > > But it fails with a NULL pointer dereference when a kdump kernel is started > on a secondary socket which has a different physical package id because the > locigal package translation for physical package 0 does not exist. > > Use the logical package id of the boot cpu instead of hard coded 0. > > [ tglx: Rewrote changelog once more ] > > Fixes: cf6d445f6897 ("perf/x86/uncore: Track packages, not per CPU data") > Signed-off-by: Prarit Bhargava > Cc: Alexander Shishkin > Cc: Arnaldo Carvalho de Melo > Cc: Borislav Petkov > Cc: H. Peter Anvin > Cc: Harish Chegondi > Cc: Jiri Olsa > Cc: Kan Liang > Cc: Linus Torvalds > Cc: Peter Zijlstra > Cc: Stephane Eranian > Cc: Thomas Gleixner > Cc: Vince Weaver > Link: http://lkml.kernel.org/r/1483628965-2890-1-git-send-email-prarit@redhat.com > Signed-off-by: Ingo Molnar > Signed-off-by: Thomas Gleixner > Signed-off-by: Greg Kroah-Hartman > > --- > arch/x86/events/intel/uncore_snbep.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/arch/x86/events/intel/uncore_snbep.c > +++ b/arch/x86/events/intel/uncore_snbep.c > @@ -2686,7 +2686,7 @@ static struct intel_uncore_type *hswep_m > > void hswep_uncore_cpu_init(void) > { > - int pkg = topology_phys_to_logical_pkg(0); > + int pkg = boot_cpu_data.logical_proc_id; > > if (hswep_uncore_cbox.num_boxes > boot_cpu_data.x86_max_cores) > hswep_uncore_cbox.num_boxes = boot_cpu_data.x86_max_cores; > >