xen/arm: missing put_cpu in xen_percpu_init

commit 0d7febe58413884f6428143221971618fbf3a47d upstream.

When CONFIG_PREEMPT is enabled, Linux will not be able to boot and warn:
[    4.127825] ------------[ cut here ]------------
[    4.133376] WARNING: at init/main.c:699 do_one_initcall+0x150/0x158()
[    4.140738] initcall xen_init_events+0x0/0x10c returned with preemption imbalance

This is because xen_percpu_init uses get_cpu but doesn't have the corresponding
put_cpu.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 13609e0..05db95d 100644 (file)
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -170,6 +170,7 @@ static void __init xen_percpu_init(void *unused)
        per_cpu(xen_vcpu, cpu) = vcpup;
 
        enable_percpu_irq(xen_events_irq, 0);
+       put_cpu();
 }
 
 static void xen_restart(char str, const char *cmd)