Re: [PATCH] KVM: arm64: timers: Fix resource leaks in kvm_timer_hyp_init()

[Oliver Upton <oliver.upton@linux.dev>]

Hi Dan,

Thanks for fixing this. Couple of small comments:

On Mon, Jun 12, 2023 at 10:07:46AM +0300, Dan Carpenter wrote:
> Smatch detected this bug:
>     arch/arm64/kvm/arch_timer.c:1425 kvm_timer_hyp_init()
>     warn: missing unwind goto?
> 
> There are a couple error paths which do not release their resources
> correctly.  Fix them.
> 
> Fixes: 9e01dc76be6a ("KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systems")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  arch/arm64/kvm/arch_timer.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
> index 05b022be885b..c2df8332d2bd 100644
> --- a/arch/arm64/kvm/arch_timer.c
> +++ b/arch/arm64/kvm/arch_timer.c
> @@ -1422,7 +1422,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
>  		if (err) {
>  			kvm_err("kvm_arch_timer: can't request ptimer interrupt %d (%d)\n",
>  				host_ptimer_irq, err);
> -			return err;
> +			goto out_free_irq;
>  		}
>  
>  		if (has_gic) {
> @@ -1430,7 +1430,7 @@ int __init kvm_timer_hyp_init(bool has_gic)
>  						    kvm_get_running_vcpus());
>  			if (err) {
>  				kvm_err("kvm_arch_timer: error setting vcpu affinity\n");
> -				goto out_free_irq;
> +				goto out_free_ptimer_irq;
>  			}
>  		}
>  
> @@ -1443,6 +1443,10 @@ int __init kvm_timer_hyp_init(bool has_gic)
>  	}
>  
>  	return 0;
> +
> +out_free_ptimer_irq:
> +	if (info->physical_irq > 0)
> +		free_percpu_irq(host_ptimer_irq, kvm_get_running_vcpus());

nit: we shouldn't even jump to this label in the first place if
there was no ptimer irq to set up... Maybe just drop the condition?

>  out_free_irq:

I'd prefer this label be renamed 'out_free_vtimer_irq' to make it
unambiguous.

>  	free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus());
>  	return err;
> -- 
> 2.39.2
> 

-- 
Thanks,
Oliver