[PATCH v2 08/22] iommufd: Abstract iopt_pin_pages and iopt_unpin_pages helpers

[Jason Gunthorpe]

On Mon, Apr 28, 2025 at 10:41:45AM -0700, Nicolin Chen wrote:
> > I'm uncertain, but perhaps pr_warn_ratelimited() would be a better
> > alternative to WARN_ON() here? WARN_ON_ONCE() generates warning messages
> > with kernel call traces in the kernel messages, which might lead users
> > to believe that something serious has happened in the kernel.
> 
> We already have similar practice, e.g. iommufd_hwpt_nested_alloc.
> 
> In my review, a WARN_ON/WARN_ON_ONCE means there is a kernel bug,
> which shouldn't occur in the first place and isn't something that

Right, so it should never happen from any ioctl path and syzkaller
should never trigger it based on system call randomization

Is that what this achieves?

Jason