kvm: async_pf: fix rcu_irq_enter() with irqs enabled

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.zwisler@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index c4ff2a9161399b92bce9a148263b79bdfb862338..c95ece93f359cecd3ad85af03aaf21f9ad6d5d09 100644 (file)
--- 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)