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    Subject[PATCH 3.10 090/139] kvm: async_pf: fix rcu_irq_enter() with irqs enabled
    Date
    From: Paolo Bonzini <pbonzini@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.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>
    ---
    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
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