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SubjectRe: [tip:x86/urgent] perf/x86/intel/uncore: Do not use hard coded physical package id 0
On 01/11/2017 05:33 AM, tip-bot for Prarit Bhargava wrote:
> Commit-ID: 42433049c51e326baa1f45c834af9572fdb65b35
> Gitweb: http://git.kernel.org/tip/42433049c51e326baa1f45c834af9572fdb65b35
> Author: Prarit Bhargava <prarit@redhat.com>
> AuthorDate: Tue, 3 Jan 2017 14:24:31 -0500
> Committer: Thomas Gleixner <tglx@linutronix.de>
> CommitDate: Wed, 11 Jan 2017 11:29:37 +0100
>
> perf/x86/intel/uncore: Do not use hard coded physical package id 0
>
> 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 physical package id of the boot cpu instead of hard coded 0.
>
> [ tglx: Rewrote changelog once more ]
>
> commit cf6d445f6897 ("perf/x86/uncore: Track packages, not per CPU data")
> Signed-off-by: Prarit Bhargava <prarit@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Kan Liang <kan.liang@intel.com>
> Cc: Harish Chegondi <harish.chegondi@intel.com>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: stable@vger.kernel.org
> Link: http://lkml.kernel.org/r/1483471471-14450-1-git-send-email-prarit@redhat.com
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> arch/x86/events/intel/uncore_snbep.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
> index e6832be..b5fbb59 100644
> --- 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_msr_uncores[] = {
>
> void hswep_uncore_cpu_init(void)
> {
> - int pkg = topology_phys_to_logical_pkg(0);
> + int pkg = topology_phys_to_logical_pkg(boot_cpu_data.phys_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;
>
>

Thomas, I self-nacked this and posted a v2. The v2 uses
boot_cpu_data.logical_proc_id instead. It was picked up here in tip by Ingo
yesterday.

http://git.kernel.org/tip/fa37361e291bfe528872b9aef5c8644a3fc7ff20

P.

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