On Wed, Jan 24, 2024, at 19:03, Elizabeth Figura wrote:

On Wednesday, 24 January 2024 01:42:19 CST Arnd Bergmann wrote:

quoted

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

quoted

@@ -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.

Hm, but there is a put_user() at the end of the function, or am I 
missing something?

No, I was just looking at the wrong thing, your version is good.

     Arnd