[PATCH 3.10 090/139] kvm: async_pf: fix rcu_irq_enter() with irqs enabled

[Willy Tarreau]

From: Paolo Bonzini <pbonz...@redhat.com>

commit bbaf0e2b1c1b4f88abd6ef49576f0efb1734eae5 upstream.

native_safe_halt enables interrupts, and you just shouldn't
call rcu_irq_enter() with interrupts enabled.  Reorder the
call with the following local_irq_disable() to respect the
invariant.

Reported-by: Ross Zwisler <ross.zwis...@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
Acked-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Tested-by: Wanpeng Li <wanpeng...@hotmail.com>
Signed-off-by: Radim Krčmář <rkrc...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

Signed-off-by: Willy Tarreau <w...@1wt.eu>
---
 arch/x86/kernel/kvm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index c4ff2a9..c95ece9 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -159,8 +159,8 @@ void kvm_async_pf_task_wait(u32 token)
                         */
                        rcu_irq_exit();
                        native_safe_halt();
-                       rcu_irq_enter();
                        local_irq_disable();
+                       rcu_irq_enter();
                }
        }
        if (!n.halted)
-- 
2.8.0.rc2.1.gbe9624a