Date: Fri, 1 Dec 2017 09:00:49 +0100
From: Christoffer Dall <cdall@linaro.org>
To: Vasyl Gomonovych <gomonovych@gmail.com>
Cc: christoffer.dall@linaro.org, marc.zyngier@arm.com,
        eric.auger@redhat.com, andre.przywara@arm.com,
        wanghaibin.wang@huawei.com, linux-arm-kernel@lists.infradead.org,
        kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: arm: Use PTR_ERR_OR_ZERO()
Message-ID: <20171201080049.GB4218@cbox>
References: <1511909297-8585-1-git-send-email-gomonovych@gmail.com>
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Hi Vasyl,

On Tue, Nov 28, 2017 at 11:48:17PM +0100, Vasyl Gomonovych wrote:
> Fix ptr_ret.cocci warnings:
> virt/kvm/arm/vgic/vgic-its.c:971:1-3: WARNING: PTR_ERR_OR_ZERO can be used
> 
> Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
> 
> Generated by: scripts/coccinelle/api/ptr_ret.cocci

For new code, sure it would make sense to use this.

But why is it worth changing existing code to use PTR_ERR_OR_ZERO?

Thanks,
-Christoffer

> 
> Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 1f761a9991e7..28d85754320b 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1032,10 +1032,8 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its,
>  
>  	device = vgic_its_alloc_device(its, device_id, itt_addr,
>  				       num_eventid_bits);
> -	if (IS_ERR(device))
> -		return PTR_ERR(device);
>  
> -	return 0;
> +	return PTR_ERR_OR_ZERO(device);
>  }
>  
>  /*
> -- 
> 1.9.1
>