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

[Elizabeth Figura]

On Wednesday, 24 January 2024 01:56:52 CST Arnd Bergmann wrote:
> 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.

That'd be nicer in general. I think there was some documentation that advised
using timespec64 for new ioctl interfaces but it may have been outdated or
misread.
> > - 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.

That's useful, thanks.