Commit | Line | Data |
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2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
1da177e4 | 2 | /* |
25985edc | 3 | * include/linux/eventpoll.h ( Efficient event polling implementation ) |
3419b23a | 4 | * Copyright (C) 2001,...,2006 Davide Libenzi |
1da177e4 | 5 | * |
1da177e4 | 6 | * Davide Libenzi <davidel@xmailserver.org> |
1da177e4 | 7 | */ |
1da177e4 LT |
8 | #ifndef _LINUX_EVENTPOLL_H |
9 | #define _LINUX_EVENTPOLL_H | |
10 | ||
607ca46e | 11 | #include <uapi/linux/eventpoll.h> |
0791e364 | 12 | #include <uapi/linux/kcmp.h> |
1da177e4 | 13 | |
1da177e4 LT |
14 | |
15 | /* Forward declarations to avoid compiler errors */ | |
16 | struct file; | |
17 | ||
18 | ||
19 | #ifdef CONFIG_EPOLL | |
20 | ||
bfe3911a | 21 | #ifdef CONFIG_KCMP |
0791e364 | 22 | struct file *get_epoll_tfile_raw_ptr(struct file *file, int tfd, unsigned long toff); |
92ef6da3 | 23 | #endif |
0791e364 | 24 | |
1da177e4 LT |
25 | /* Used to release the epoll bits inside the "struct file" */ |
26 | void eventpoll_release_file(struct file *file); | |
27 | ||
28 | /* | |
29 | * This is called from inside fs/file_table.c:__fput() to unlink files | |
30 | * from the eventpoll interface. We need to have this facility to cleanup | |
31 | * correctly files that are closed without being removed from the eventpoll | |
32 | * interface. | |
33 | */ | |
34 | static inline void eventpoll_release(struct file *file) | |
35 | { | |
36 | ||
37 | /* | |
38 | * Fast check to avoid the get/release of the semaphore. Since | |
39 | * we're doing this outside the semaphore lock, it might return | |
40 | * false negatives, but we don't care. It'll help in 99.99% of cases | |
41 | * to avoid the semaphore lock. False positives simply cannot happen | |
42 | * because the file in on the way to be removed and nobody ( but | |
43 | * eventpoll ) has still a reference to this file. | |
44 | */ | |
319c1517 | 45 | if (likely(!file->f_ep)) |
1da177e4 LT |
46 | return; |
47 | ||
48 | /* | |
49 | * The file is being closed while it is still linked to an epoll | |
50 | * descriptor. We need to handle this by correctly unlinking it | |
51 | * from its containers. | |
52 | */ | |
53 | eventpoll_release_file(file); | |
54 | } | |
55 | ||
39220e8d JA |
56 | int do_epoll_ctl(int epfd, int op, int fd, struct epoll_event *epds, |
57 | bool nonblock); | |
58 | ||
59 | /* Tells if the epoll_ctl(2) operation needs an event copy from userspace */ | |
60 | static inline int ep_op_has_event(int op) | |
61 | { | |
62 | return op != EPOLL_CTL_DEL; | |
63 | } | |
64 | ||
1da177e4 LT |
65 | #else |
66 | ||
1da177e4 LT |
67 | static inline void eventpoll_release(struct file *file) {} |
68 | ||
69 | #endif | |
70 | ||
249dbe74 AB |
71 | #if defined(CONFIG_ARM) && defined(CONFIG_OABI_COMPAT) |
72 | /* ARM OABI has an incompatible struct layout and needs a special handler */ | |
73 | extern struct epoll_event __user * | |
74 | epoll_put_uevent(__poll_t revents, __u64 data, | |
75 | struct epoll_event __user *uevent); | |
76 | #else | |
77 | static inline struct epoll_event __user * | |
78 | epoll_put_uevent(__poll_t revents, __u64 data, | |
79 | struct epoll_event __user *uevent) | |
80 | { | |
81 | if (__put_user(revents, &uevent->events) || | |
82 | __put_user(data, &uevent->data)) | |
83 | return NULL; | |
84 | ||
85 | return uevent+1; | |
86 | } | |
87 | #endif | |
88 | ||
1da177e4 | 89 | #endif /* #ifndef _LINUX_EVENTPOLL_H */ |