[patch 35/60] KVM: ia64: Fix irq disabling leak in error handlingcode

[Greg KH]

2.6.26-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Julia Lawall <julia@xxxxxxx>

(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@xxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/ia64/kvm/kvm-ia64.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -125,9 +125,9 @@ void kvm_arch_hardware_enable(void *garb
 				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 *gar
 
 	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_vcp
 uninit:
 	kvm_vcpu_uninit(vcpu);
 fail:
+	local_irq_restore(psr);
 	return r;
 }
 

-- 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/