On Wed, Jan 24, 2024, at 01:40, Elizabeth Figura wrote: > @@ -738,6 +803,8 @@ static long ntsync_char_ioctl(struct file *file, > diff --git a/include/uapi/linux/ntsync.h b/include/uapi/linux/ntsync.h > index 26d1b3d4847f..2e44e7e77776 100644 > --- a/include/uapi/linux/ntsync.h > +++ b/include/uapi/linux/ntsync.h > @@ -46,5 +46,7 @@ struct ntsync_wait_args { > struct ntsync_wait_args) > #define NTSYNC_IOC_CREATE_MUTEX _IOWR(NTSYNC_IOC_BASE, 5, \ > struct ntsync_mutex_args) > +#define NTSYNC_IOC_PUT_MUTEX _IOWR(NTSYNC_IOC_BASE, 6, \ > + struct ntsync_mutex_args) > In your implementation, this argument is not written back to user space, so I think this should be _IOW rather than than _IORW. Again, no practical difference here. Arnd