KVM: ia64: Fix irq disabling leak in error handling code

(cherry picked from commit cab7a1eeeb007be309cd99cf14407261a72d2418)

There is a call to local_irq_restore in the normal exit case, so it would
seem that there should be one on an error return as well.

The semantic patch that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression l;
expression E,E1,E2;
@@

local_irq_save(l);
... when != local_irq_restore(l)
    when != spin_unlock_irqrestore(E,l)
    when any
    when strict
(
if (...) { ... when != local_irq_restore(l)
               when != spin_unlock_irqrestore(E1,l)
+   local_irq_restore(l);
    return ...;
}
|
if (...)
+   {local_irq_restore(l);
    return ...;
+   }
|
spin_unlock_irqrestore(E2,l);
|
local_irq_restore(l);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 5152ba043abe5ebea0e853a9d0f637243d9eec29..778de8dabef4405a7999fe7898272785bd96ba58 100644 (file)
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -125,9 +125,9 @@ void kvm_arch_hardware_enable(void *garbage)
                                PAGE_KERNEL));
        local_irq_save(saved_psr);
        slot = ia64_itr_entry(0x3, KVM_VMM_BASE, pte, KVM_VMM_SHIFT);
+       local_irq_restore(saved_psr);
        if (slot < 0)
                return;
-       local_irq_restore(saved_psr);
 
        spin_lock(&vp_lock);
        status = ia64_pal_vp_init_env(kvm_vsa_base ?
@@ -160,9 +160,9 @@ void kvm_arch_hardware_disable(void *garbage)
 
        local_irq_save(saved_psr);
        slot = ia64_itr_entry(0x3, KVM_VMM_BASE, pte, KVM_VMM_SHIFT);
+       local_irq_restore(saved_psr);
        if (slot < 0)
                return;
-       local_irq_restore(saved_psr);
 
        status = ia64_pal_vp_exit_env(host_iva);
        if (status)
@@ -1258,6 +1258,7 @@ static int vti_vcpu_setup(struct kvm_vcpu *vcpu, int id)
 uninit:
        kvm_vcpu_uninit(vcpu);
 fail:
+       local_irq_restore(psr);
        return r;
 }