Re: [cocci] [PATCH 46/61] vfio: Prefer IS_ERR_OR_NULL over manual NULL check

Alex Williamson <[email protected]> Mon, 16 Mar 2026 16:10:50 -0600
Newsgroups fr.inria.cocci,dev.linux.lists.dm-devel,dev.linux.lists.gfs2,dev.linux.lists.iommu,dev.linux.lists.ntfs3,dev.linux.lists.sched-ext,dev.linux.lists.v9fs,org.freedesktop.lists.amd-gfx,org.freedesktop.lists.dri-devel,org.freedesktop.lists.intel-gfx,org.infradead.lists.linux-mtd,org.infradead.lists.linux-phy,org.infradead.lists.linux-rockchip,org.kernel.vger.bpf,org.kernel.vger.ceph-devel,org.kernel.vger.kvm,org.kernel.vger.linux-block,org.kernel.vger.linux-bluetooth,org.kernel.vger.linux-btrfs,org.kernel.vger.linux-cifs,org.kernel.vger.linux-clk,org.kernel.vger.linux-ext4,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-gpio,org.kernel.vger.linux-hyperv,org.kernel.vger.linux-input,org.kernel.vger.linux-kernel,org.kernel.vger.linux-leds,org.kernel.vger.linux-media,org.kernel.vger.linux-mips,org.kernel.vger.linux-modules,org.kernel.vger.linux-nfs,org.kernel.vger.linux-omap,org.kernel.vger.linux-pm,org.kernel.vger.linux-s390,org.kernel.vger.linux-scsi,org.kernel.vger.linux-sctp,org.kernel.vger.linux-security-module,org.kernel.vger.linux-sh,org.kernel.vger.linux-sound,org.kernel.vger.linux-trace-kernel,org.kernel.vger.linux-usb,org.kernel.vger.linux-wireless,org.kernel.vger.netdev,org.kernel.vger.target-devel,org.kvack.linux-mm,org.osuosl.intel-wired-lan,org.ozlabs.lists.linux-erofs
Message-ID <[email protected]> 
On Tue, 10 Mar 2026 12:49:12 +0100
Philipp Hahn <[email protected]> wrote:

> Prefer using IS_ERR_OR_NULL() over using IS_ERR() and a manual NULL
> check.
> 
> Change generated with coccinelle.
> 
> To: Alex Williamson <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Philipp Hahn <[email protected]>
> ---
>  drivers/vfio/vfio_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 742477546b15d4dbaf9ebcfb2e67627db71521e0..d71922dfde5885967398deddec3e9e04b05adfec 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -923,7 +923,7 @@ vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device,
>  
>  	/* Handle the VFIO_DEVICE_FEATURE_SET */
>  	filp = device->mig_ops->migration_set_state(device, mig.device_state);
> -	if (IS_ERR(filp) || !filp)
> +	if (IS_ERR_OR_NULL(filp))
>  		goto out_copy;
>  
>  	return vfio_ioct_mig_return_fd(filp, arg, &mig);
> 

As others have expressed in general, this doesn't seem to be cleaner
and tends to mask that we consider IS_ERR() and NULL as separate cases
in the goto.  This code looks like it could use some refactoring, and
likely that refactoring should handle the IS_ERR() and NULL cases
separately, but conflating them here is not an improvement.  Thanks,

Alex