Re: [PATCH v2 7/7] blk-zoned: implement ioctls

[Christoph Hellwig <hch@infradead.org>]

> +	zones = kzalloc(sizeof(struct blk_zone) * rep.nr_zones,
> +			GFP_KERNEL);
> +	if (!zones)
> +		return -ENOMEM;

This should use kcalloc to get us underflow checking for the user
controlled allocation size.

> +	if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
> +		ret = -EFAULT;
> +		goto out;
> +	}
> +
> +	if (rep.nr_zones) {
> +		if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
> +				 sizeof(struct blk_zone) * rep.nr_zones))
> +			ret = -EFAULT;
> +	}

We could actually do this with a single big copy_to_user.  Not that
it really matters, though..

> -/*
> - * Zone type.
> - */
> -enum blk_zone_type {
> -	BLK_ZONE_TYPE_UNKNOWN,
> -	BLK_ZONE_TYPE_CONVENTIONAL,
> -	BLK_ZONE_TYPE_SEQWRITE_REQ,
> -	BLK_ZONE_TYPE_SEQWRITE_PREF,
> -};

Please don't move this code around after it was added just two
patches earlier.  I'd say just split adding the new blkzoned.h
uapi header into a patch of it's own and add that before the
core block code.