xen/x86: fix cpu hotplug
authorJuergen Gross <jgross@suse.com>
Wed, 5 Jul 2017 14:05:20 +0000 (16:05 +0200)
committerJuergen Gross <jgross@suse.com>
Sun, 23 Jul 2017 06:13:11 +0000 (08:13 +0200)
commitc185ddec54657c145a0c2055e4b87918da24974f
tree534b075a9ed9871aed3983cfaa86c7111310b69d
parent29d11cfd8698038b87458ba4d1329b9da81150a5
xen/x86: fix cpu hotplug

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().

Cc: <stable@vger.kernel.org> # 4.12
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
arch/x86/xen/smp_pv.c