On Wed, Feb 07, 2024 at 09:37:14AM +0100, Jiri Slaby wrote:

On 05. 02. 24, 22:04, Joe Damato wrote:

quoted

Add an ioctl for getting and setting epoll_params. User programs can use
this ioctl to get and set the busy poll usec time, packet budget, and
prefer busy poll params for a specific epoll context.

Parameters are limited:
  - busy_poll_usecs is limited to <= u32_max
  - busy_poll_budget is limited to <= NAPI_POLL_WEIGHT by unprivileged
    users (!capable(CAP_NET_ADMIN))
  - prefer_busy_poll must be 0 or 1
  - __pad must be 0

Signed-off-by: Joe Damato <redacted>

...

quoted

--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c

...

quoted

@@ -497,6 +498,50 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi)
 	ep->napi_id = napi_id;
 }
+static long ep_eventpoll_bp_ioctl(struct file *file, unsigned int cmd,
+				  unsigned long arg)
+{
+	struct eventpoll *ep;
+	struct epoll_params epoll_params;
+	void __user *uarg = (void __user *) arg;
+
+	ep = file->private_data;

This might have been on the ep declaration line.

quoted

+	switch (cmd) {
+	case EPIOCSPARAMS:
+		if (copy_from_user(&epoll_params, uarg, sizeof(epoll_params)))
+			return -EFAULT;
+
+		if (memchr_inv(epoll_params.__pad, 0, sizeof(epoll_params.__pad)))
+			return -EINVAL;
+
+		if (epoll_params.busy_poll_usecs > U32_MAX)
+			return -EINVAL;
+
+		if (epoll_params.prefer_busy_poll > 1)
+			return -EINVAL;
+
+		if (epoll_params.busy_poll_budget > NAPI_POLL_WEIGHT &&
+		    !capable(CAP_NET_ADMIN))
+			return -EPERM;
+
+		ep->busy_poll_usecs = epoll_params.busy_poll_usecs;
+		ep->busy_poll_budget = epoll_params.busy_poll_budget;
+		ep->prefer_busy_poll = !!epoll_params.prefer_busy_poll;

This !! is unnecessary. Nonzero values shall be "converted" to true.

But FWIW, the above is nothing which should be blocking, so:

"> 

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>

netdev maintainers: Jiri marked this with Reviewed-by, but was this review
what caused "Changes Requested" to be the status set for this patch set in
patchwork?

If needed, I'll send a v7 with the changes Jiri suggested and add the
"Reviewed-by" since the changes are cosmetic, but I wanted to make sure
this was the reason.

Thanks.