Re: [PATCH 1/2] arch/ia64/kvm/kvm-ia64.c: Add local_irq_restore inerror handling code

From: Simon Holm Thøgersen
Date: Tue Jul 22 2008 - 15:10:41 EST


tir, 22 07 2008 kl. 18:44 +0200, skrev Julia Lawall:
> From: Julia Lawall <julia@xxxxxxx>
>
> 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 makes this change 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>
>
> ---
> arch/ia64/kvm/kvm-ia64.c | 9 +++++++--
> 1 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
> index 318b811..14e5c99 100644
> --- a/arch/ia64/kvm/kvm-ia64.c
> +++ b/arch/ia64/kvm/kvm-ia64.c
> @@ -125,8 +125,10 @@ 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);
> - if (slot < 0)
> + if (slot < 0) {
> + local_irq_restore(saved_psr);
> return;
> + }
> local_irq_restore(saved_psr);

If this change makes sense, how about merging the two local_irq_restore
calls and put them before the if? And shouldn't your checker be able to
figure this?

>
> spin_lock(&vp_lock);
> @@ -160,8 +162,10 @@ void kvm_arch_hardware_disable(void *garbage)
>
> local_irq_save(saved_psr);
> slot = ia64_itr_entry(0x3, KVM_VMM_BASE, pte, KVM_VMM_SHIFT);
> - if (slot < 0)
> + if (slot < 0) {
> + local_irq_restore(saved_psr);
> return;
> + }
> local_irq_restore(saved_psr);
>
Same as above.

> status = ia64_pal_vp_exit_env(host_iva);
> @@ -1258,6 +1262,7 @@ static int vti_vcpu_setup(struct kvm_vcpu *vcpu, int id)
> uninit:
> kvm_vcpu_uninit(vcpu);
> fail:
> + local_irq_restore(psr);
> return r;
> }
>
> --
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