eventpoll: add epoll_sendevents() helper

Basic helper that copies ready events to the specified userspace
address. The event checking is quick and racy, it's up to the caller
to ensure it retries appropriately in case 0 events are copied.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20250219172552.1565603-4-axboe@kernel.dk
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Jens Axboe
2025-02-19 10:22:26 -07:00
committed by Christian Brauner
parent 38d2035601
commit ae3a4f1fdc
2 changed files with 24 additions and 0 deletions

View File

@@ -2474,6 +2474,26 @@ static int ep_check_params(struct file *file, struct epoll_event __user *evs,
return 0;
}
int epoll_sendevents(struct file *file, struct epoll_event __user *events,
int maxevents)
{
struct eventpoll *ep;
int ret;
ret = ep_check_params(file, events, maxevents);
if (unlikely(ret))
return ret;
ep = file->private_data;
/*
* Racy call, but that's ok - it should get retried based on
* poll readiness anyway.
*/
if (ep_events_available(ep))
return ep_try_send_events(ep, events, maxevents);
return 0;
}
/*
* Implement the event wait interface for the eventpoll file. It is the kernel
* part of the user space epoll_wait(2).