Re: [PATCH] staging: kpc2000: fix alloc_cast.cocci warnings

From: Greg Kroah-Hartman
Date: Wed May 15 2019 - 09:18:05 EST


On Wed, May 15, 2019 at 08:16:15PM +0800, kbuild test robot wrote:
> From: kbuild test robot <lkp@xxxxxxxxx>
>
> drivers/staging/kpc2000/kpc_dma/fileops.c:60:8-26: WARNING: casting value returned by memory allocation function to (struct aio_cb_data *) is useless.
>
> Remove casting the values returned by memory allocation functions
> like kmalloc, kzalloc, kmem_cache_alloc, kmem_cache_zalloc etc.
>
> Semantic patch information:
> This makes an effort to find cases of casting of values returned by
> kmalloc, kzalloc, kcalloc, kmem_cache_alloc, kmem_cache_zalloc,
> kmem_cache_alloc_node, kmalloc_node and kzalloc_node and removes
> the casting as it is not required. The result in the patch case may
> need some reformatting.
>
> Generated by: scripts/coccinelle/api/alloc/alloc_cast.cocci
>
> Fixes: 7df95299b94a ("staging: kpc2000: Add DMA driver")
> CC: Matt Sickler <Matt.Sickler@xxxxxxxxxxxxxx>
> Signed-off-by: kbuild test robot <lkp@xxxxxxxxx>
> ---
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 5ac94332248ee017964ba368cdda4ce647e3aba7
> commit: 7df95299b94a63ec67a6389fc02dc25019a80ee8 staging: kpc2000: Add DMA driver
>
> fileops.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/drivers/staging/kpc2000/kpc_dma/fileops.c
> +++ b/drivers/staging/kpc2000/kpc_dma/fileops.c
> @@ -57,7 +57,7 @@ int kpc_dma_transfer(struct dev_private
>
> dev_dbg(&priv->ldev->pldev->dev, "kpc_dma_transfer(priv = [%p], kcb = [%p], iov_base = [%p], iov_len = %ld) ldev = [%p]\n", priv, kcb, (void*)iov_base, iov_len, ldev);
>
> - acd = (struct aio_cb_data *) kzalloc(sizeof(struct aio_cb_data), GFP_KERNEL);
> + acd = kzalloc(sizeof(struct aio_cb_data), GFP_KERNEL);
> if (!acd){
> dev_err(&priv->ldev->pldev->dev, "Couldn't kmalloc space for for the aio data\n");
> return -ENOMEM;

Already fixed in my staging-testing branch, thanks.

greg k-h