1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_POLL_H 2 #ifndef _LINUX_POLL_H
3 #define _LINUX_POLL_H 3 #define _LINUX_POLL_H
4 4
5 5
6 #include <linux/compiler.h> 6 #include <linux/compiler.h>
7 #include <linux/ktime.h> 7 #include <linux/ktime.h>
8 #include <linux/wait.h> 8 #include <linux/wait.h>
9 #include <linux/string.h> 9 #include <linux/string.h>
10 #include <linux/fs.h> 10 #include <linux/fs.h>
>> 11 #include <linux/sysctl.h>
11 #include <linux/uaccess.h> 12 #include <linux/uaccess.h>
12 #include <uapi/linux/poll.h> 13 #include <uapi/linux/poll.h>
13 #include <uapi/linux/eventpoll.h> 14 #include <uapi/linux/eventpoll.h>
14 15
>> 16 extern struct ctl_table epoll_table[]; /* for sysctl */
15 /* ~832 bytes of stack space used max in sys_s 17 /* ~832 bytes of stack space used max in sys_select/sys_poll before allocating
16 additional memory. */ 18 additional memory. */
17 #define MAX_STACK_ALLOC 832 19 #define MAX_STACK_ALLOC 832
18 #define FRONTEND_STACK_ALLOC 256 20 #define FRONTEND_STACK_ALLOC 256
19 #define SELECT_STACK_ALLOC FRONTEND_STACK 21 #define SELECT_STACK_ALLOC FRONTEND_STACK_ALLOC
20 #define POLL_STACK_ALLOC FRONTEND_STACK 22 #define POLL_STACK_ALLOC FRONTEND_STACK_ALLOC
21 #define WQUEUES_STACK_ALLOC (MAX_STACK_ALL 23 #define WQUEUES_STACK_ALLOC (MAX_STACK_ALLOC - FRONTEND_STACK_ALLOC)
22 #define N_INLINE_POLL_ENTRIES (WQUEUES_STACK 24 #define N_INLINE_POLL_ENTRIES (WQUEUES_STACK_ALLOC / sizeof(struct poll_table_entry))
23 25
24 #define DEFAULT_POLLMASK (EPOLLIN | EPOLLOUT | 26 #define DEFAULT_POLLMASK (EPOLLIN | EPOLLOUT | EPOLLRDNORM | EPOLLWRNORM)
25 27
26 struct poll_table_struct; 28 struct poll_table_struct;
27 29
28 /* 30 /*
29 * structures and helpers for f_op->poll imple 31 * structures and helpers for f_op->poll implementations
30 */ 32 */
31 typedef void (*poll_queue_proc)(struct file *, 33 typedef void (*poll_queue_proc)(struct file *, wait_queue_head_t *, struct poll_table_struct *);
32 34
33 /* 35 /*
34 * Do not touch the structure directly, use th 36 * Do not touch the structure directly, use the access functions
35 * poll_does_not_wait() and poll_requested_eve 37 * poll_does_not_wait() and poll_requested_events() instead.
36 */ 38 */
37 typedef struct poll_table_struct { 39 typedef struct poll_table_struct {
38 poll_queue_proc _qproc; 40 poll_queue_proc _qproc;
39 __poll_t _key; 41 __poll_t _key;
40 } poll_table; 42 } poll_table;
41 43
42 static inline void poll_wait(struct file * fil 44 static inline void poll_wait(struct file * filp, wait_queue_head_t * wait_address, poll_table *p)
43 { 45 {
44 if (p && p->_qproc && wait_address) 46 if (p && p->_qproc && wait_address)
45 p->_qproc(filp, wait_address, 47 p->_qproc(filp, wait_address, p);
46 } 48 }
47 49
48 /* 50 /*
49 * Return true if it is guaranteed that poll w 51 * Return true if it is guaranteed that poll will not wait. This is the case
50 * if the poll() of another file descriptor in 52 * if the poll() of another file descriptor in the set got an event, so there
51 * is no need for waiting. 53 * is no need for waiting.
52 */ 54 */
53 static inline bool poll_does_not_wait(const po 55 static inline bool poll_does_not_wait(const poll_table *p)
54 { 56 {
55 return p == NULL || p->_qproc == NULL; 57 return p == NULL || p->_qproc == NULL;
56 } 58 }
57 59
58 /* 60 /*
59 * Return the set of events that the applicati 61 * Return the set of events that the application wants to poll for.
60 * This is useful for drivers that need to kno 62 * This is useful for drivers that need to know whether a DMA transfer has
61 * to be started implicitly on poll(). You typ 63 * to be started implicitly on poll(). You typically only want to do that
62 * if the application is actually polling for 64 * if the application is actually polling for POLLIN and/or POLLOUT.
63 */ 65 */
64 static inline __poll_t poll_requested_events(c 66 static inline __poll_t poll_requested_events(const poll_table *p)
65 { 67 {
66 return p ? p->_key : ~(__poll_t)0; 68 return p ? p->_key : ~(__poll_t)0;
67 } 69 }
68 70
69 static inline void init_poll_funcptr(poll_tabl 71 static inline void init_poll_funcptr(poll_table *pt, poll_queue_proc qproc)
70 { 72 {
71 pt->_qproc = qproc; 73 pt->_qproc = qproc;
72 pt->_key = ~(__poll_t)0; /* all even 74 pt->_key = ~(__poll_t)0; /* all events enabled */
73 } 75 }
74 76
75 static inline bool file_can_poll(struct file * 77 static inline bool file_can_poll(struct file *file)
76 { 78 {
77 return file->f_op->poll; 79 return file->f_op->poll;
78 } 80 }
79 81
80 static inline __poll_t vfs_poll(struct file *f 82 static inline __poll_t vfs_poll(struct file *file, struct poll_table_struct *pt)
81 { 83 {
82 if (unlikely(!file->f_op->poll)) 84 if (unlikely(!file->f_op->poll))
83 return DEFAULT_POLLMASK; 85 return DEFAULT_POLLMASK;
84 return file->f_op->poll(file, pt); 86 return file->f_op->poll(file, pt);
85 } 87 }
86 88
87 struct poll_table_entry { 89 struct poll_table_entry {
88 struct file *filp; 90 struct file *filp;
89 __poll_t key; 91 __poll_t key;
90 wait_queue_entry_t wait; 92 wait_queue_entry_t wait;
91 wait_queue_head_t *wait_address; 93 wait_queue_head_t *wait_address;
92 }; 94 };
93 95
94 /* 96 /*
95 * Structures and helpers for select/poll sysc 97 * Structures and helpers for select/poll syscall
96 */ 98 */
97 struct poll_wqueues { 99 struct poll_wqueues {
98 poll_table pt; 100 poll_table pt;
99 struct poll_table_page *table; 101 struct poll_table_page *table;
100 struct task_struct *polling_task; 102 struct task_struct *polling_task;
101 int triggered; 103 int triggered;
102 int error; 104 int error;
103 int inline_index; 105 int inline_index;
104 struct poll_table_entry inline_entries 106 struct poll_table_entry inline_entries[N_INLINE_POLL_ENTRIES];
105 }; 107 };
106 108
107 extern void poll_initwait(struct poll_wqueues 109 extern void poll_initwait(struct poll_wqueues *pwq);
108 extern void poll_freewait(struct poll_wqueues 110 extern void poll_freewait(struct poll_wqueues *pwq);
109 extern u64 select_estimate_accuracy(struct tim 111 extern u64 select_estimate_accuracy(struct timespec64 *tv);
110 112
111 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1 113 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
112 114
113 extern int core_sys_select(int n, fd_set __use 115 extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
114 fd_set __user *exp, 116 fd_set __user *exp, struct timespec64 *end_time);
115 117
116 extern int poll_select_set_timeout(struct time 118 extern int poll_select_set_timeout(struct timespec64 *to, time64_t sec,
117 long nsec); 119 long nsec);
118 120
119 #define __MAP(v, from, to) \ 121 #define __MAP(v, from, to) \
120 (from < to ? (v & from) * (to/from) : 122 (from < to ? (v & from) * (to/from) : (v & from) / (from/to))
121 123
122 static inline __u16 mangle_poll(__poll_t val) 124 static inline __u16 mangle_poll(__poll_t val)
123 { 125 {
124 __u16 v = (__force __u16)val; 126 __u16 v = (__force __u16)val;
125 #define M(X) __MAP(v, (__force __u16)EPOLL##X, 127 #define M(X) __MAP(v, (__force __u16)EPOLL##X, POLL##X)
126 return M(IN) | M(OUT) | M(PRI) | M(ERR 128 return M(IN) | M(OUT) | M(PRI) | M(ERR) | M(NVAL) |
127 M(RDNORM) | M(RDBAND) | M(WRNO 129 M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
128 M(HUP) | M(RDHUP) | M(MSG); 130 M(HUP) | M(RDHUP) | M(MSG);
129 #undef M 131 #undef M
130 } 132 }
131 133
132 static inline __poll_t demangle_poll(u16 val) 134 static inline __poll_t demangle_poll(u16 val)
133 { 135 {
134 #define M(X) (__force __poll_t)__MAP(val, POLL 136 #define M(X) (__force __poll_t)__MAP(val, POLL##X, (__force __u16)EPOLL##X)
135 return M(IN) | M(OUT) | M(PRI) | M(ERR 137 return M(IN) | M(OUT) | M(PRI) | M(ERR) | M(NVAL) |
136 M(RDNORM) | M(RDBAND) | M(WRNO 138 M(RDNORM) | M(RDBAND) | M(WRNORM) | M(WRBAND) |
137 M(HUP) | M(RDHUP) | M(MSG); 139 M(HUP) | M(RDHUP) | M(MSG);
138 #undef M 140 #undef M
139 } 141 }
140 #undef __MAP 142 #undef __MAP
141 143
142 144
143 #endif /* _LINUX_POLL_H */ 145 #endif /* _LINUX_POLL_H */
144 146
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