blob: 3337745d81bd6947c6181bd9f2df3eaf013f0b04 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0-or-later */
* include/linux/eventpoll.h ( Efficient event polling implementation )
* Copyright (C) 2001,...,2006 Davide Libenzi
* Davide Libenzi <>
#include <uapi/linux/eventpoll.h>
#include <uapi/linux/kcmp.h>
/* Forward declarations to avoid compiler errors */
struct file;
struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, unsigned long toff);
/* Used to release the epoll bits inside the "struct file" */
void eventpoll_release_file(struct file *file);
* This is called from inside fs/file_table.c:__fput() to unlink files
* from the eventpoll interface. We need to have this facility to cleanup
* correctly files that are closed without being removed from the eventpoll
* interface.
static inline void eventpoll_release(struct file *file)
* Fast check to avoid the get/release of the semaphore. Since
* we're doing this outside the semaphore lock, it might return
* false negatives, but we don't care. It'll help in 99.99% of cases
* to avoid the semaphore lock. False positives simply cannot happen
* because the file in on the way to be removed and nobody ( but
* eventpoll ) has still a reference to this file.
if (likely(!file->f_ep))
* The file is being closed while it is still linked to an epoll
* descriptor. We need to handle this by correctly unlinking it
* from its containers.
int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds,
bool nonblock);
/* Tells if the epoll_ctl(2) operation needs an event copy from userspace */
static inline int ep_op_has_event(int op)
return op != EPOLL_CTL_DEL;
static inline void eventpoll_release(struct file *file) {}
#if defined(CONFIG_ARM) && defined(CONFIG_OABI_COMPAT)
/* ARM OABI has an incompatible struct layout and needs a special handler */
extern struct epoll_event __user *
epoll_put_uevent(__poll_t revents, __u64 data,
struct epoll_event __user *uevent);
static inline struct epoll_event __user *
epoll_put_uevent(__poll_t revents, __u64 data,
struct epoll_event __user *uevent)
if (__put_user(revents, &uevent->events) ||
__put_user(data, &uevent->data))
return NULL;
return uevent+1;
#endif /* #ifndef _LINUX_EVENTPOLL_H */