Re: [RFC PATCH 5/9] ntsync: Introduce NTSYNC_IOC_WAIT_ANY.

[Arnd Bergmann]

On Wed, Jan 24, 2024, at 01:40, Elizabeth Figura wrote:

> +	if (args->timeout) {
> +		struct timespec64 to;
> +
> +		if (get_timespec64(&to, u64_to_user_ptr(args->timeout)))
> +			return -EFAULT;
> +		if (!timespec64_valid(&to))
> +			return -EINVAL;
> +
> +		timeout = timespec64_to_ns(&to);
> +	}

Have you considered just passing the nanosecond value here?
Since you do not appear to write it back, that would avoid
the complexities of dealing with timespec layout differences
and indirection.

> +	ids = kmalloc_array(count, sizeof(*ids), GFP_KERNEL);
> +	if (!ids)
> +		return -ENOMEM;
> +	if (copy_from_user(ids, u64_to_user_ptr(args->objs),
> +			   array_size(count, sizeof(*ids)))) {
> +		kfree(ids);
> +		return -EFAULT;
> +	}

This looks like memdup_user() would be slightly simpler.

      Arnd