From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53956 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753128AbdGYAF1 (ORCPT ); Mon, 24 Jul 2017 20:05:27 -0400 Subject: Patch "xen/x86: fix cpu hotplug" has been added to the 4.12-stable tree To: jgross@suse.com, boris.ostrovsky@oracle.com, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 24 Jul 2017 17:05:20 -0700 Message-ID: <1500941120108161@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled xen/x86: fix cpu hotplug to the 4.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: xen-x86-fix-cpu-hotplug.patch and it can be found in the queue-4.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From c185ddec54657c145a0c2055e4b87918da24974f Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 5 Jul 2017 16:05:20 +0200 Subject: xen/x86: fix cpu hotplug From: Juergen Gross commit c185ddec54657c145a0c2055e4b87918da24974f upstream. Commit dc6416f1d711eb4c1726e845d653235dcaae12e1 ("xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()") introduced an error leading to a stack overflow of the idle task when a cpu was brought offline/online many times: by calling cpu_startup_entry() instead of returning at the end of xen_play_dead() do_idle() would be entered again and again. Don't use cpu_startup_entry(), but cpuhp_online_idle() instead allowing to return from xen_play_dead(). Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- arch/x86/xen/smp_pv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -417,7 +418,7 @@ static void xen_pv_play_dead(void) /* us */ tick_nohz_idle_enter(); - cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); + cpuhp_online_idle(CPUHP_AP_ONLINE_IDLE); } #else /* !CONFIG_HOTPLUG_CPU */ Patches currently in stable-queue which might be from jgross@suse.com are queue-4.12/xen-x86-fix-cpu-hotplug.patch queue-4.12/xen-scsiback-fix-a-tmr-related-use-after-free.patch