1 #ifndef _LINUX_SEM_H
2 #define _LINUX_SEM_H
3
4 #include <linux/ipc.h>
5 #include <asm/atomic.h>
6
7 /* semop flags */
8 #define SEM_UNDO 0x1000 /* undo the operation on exit */
9
10 /* semctl Command Definitions. */
11 #define GETPID 11 /* get sempid */
12 #define GETVAL 12 /* get semval */
13 #define GETALL 13 /* get all semval's */
14 #define GETNCNT 14 /* get semncnt */
15 #define GETZCNT 15 /* get semzcnt */
16 #define SETVAL 16 /* set semval */
17 #define SETALL 17 /* set all semval's */
18
19 /* ipcs ctl cmds */
20 #define SEM_STAT 18
21 #define SEM_INFO 19
22
23 /* Obsolete, used only for backwards compatibility and libc5 compiles */
24 struct semid_ds {
25 struct ipc_perm sem_perm; /* permissions .. see ipc.h */
26 __kernel_time_t sem_otime; /* last semop time */
27 __kernel_time_t sem_ctime; /* last change time */
28 struct sem *sem_base; /* ptr to first semaphore in array */
29 struct sem_queue *sem_pending; /* pending operations to be processed */
30 struct sem_queue **sem_pending_last; /* last pending operation */
31 struct sem_undo *undo; /* undo requests on this array */
32 unsigned short sem_nsems; /* no. of semaphores in array */
33 };
34
35 /* Include the definition of semid64_ds */
36 #include <asm/sembuf.h>
37
38 /* semop system calls takes an array of these. */
39 struct sembuf {
40 unsigned short sem_num; /* semaphore index in array */
41 short sem_op; /* semaphore operation */
42 short sem_flg; /* operation flags */
43 };
44
45 /* arg for semctl system calls. */
46 union semun {
47 int val; /* value for SETVAL */
48 struct semid_ds __user *buf; /* buffer for IPC_STAT & IPC_SET */
49 unsigned short __user *array; /* array for GETALL & SETALL */
50 struct seminfo __user *__buf; /* buffer for IPC_INFO */
51 void __user *__pad;
52 };
53
54 struct seminfo {
55 int semmap;
56 int semmni;
57 int semmns;
58 int semmnu;
59 int semmsl;
60 int semopm;
61 int semume;
62 int semusz;
63 int semvmx;
64 int semaem;
65 };
66
67 #define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */
68 #define SEMMSL 250 /* <= 8 000 max num of semaphores per id */
69 #define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
70 #define SEMOPM 32 /* <= 1 000 max num of ops per semop call */
71 #define SEMVMX 32767 /* <= 32767 semaphore maximum value */
72 #define SEMAEM SEMVMX /* adjust on exit max value */
73
74 /* unused */
75 #define SEMUME SEMOPM /* max num of undo entries per process */
76 #define SEMMNU SEMMNS /* num of undo structures system wide */
77 #define SEMMAP SEMMNS /* # of entries in semaphore map */
78 #define SEMUSZ 20 /* sizeof struct sem_undo */
79
80 #ifdef __KERNEL__
81
82 /* One semaphore structure for each semaphore in the system. */
83 struct sem {
84 int semval; /* current value */
85 int sempid; /* pid of last operation */
86 };
87
88 /* One sem_array data structure for each set of semaphores in the system. */
89 struct sem_array {
90 struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */
91 time_t sem_otime; /* last semop time */
92 time_t sem_ctime; /* last change time */
93 struct sem *sem_base; /* ptr to first semaphore in array */
94 struct sem_queue *sem_pending; /* pending operations to be processed */
95 struct sem_queue **sem_pending_last; /* last pending operation */
96 struct sem_undo *undo; /* undo requests on this array */
97 unsigned long sem_nsems; /* no. of semaphores in array */
98 };
99
100 /* One queue for each sleeping process in the system. */
101 struct sem_queue {
102 struct sem_queue * next; /* next entry in the queue */
103 struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */
104 struct task_struct* sleeper; /* this process */
105 struct sem_undo * undo; /* undo structure */
106 int pid; /* process id of requesting process */
107 int status; /* completion status of operation */
108 struct sem_array * sma; /* semaphore array for operations */
109 int id; /* internal sem id */
110 struct sembuf * sops; /* array of pending operations */
111 int nsops; /* number of operations */
112 int alter; /* does the operation alter the array? */
113 };
114
115 /* Each task has a list of undo requests. They are executed automatically
116 * when the process exits.
117 */
118 struct sem_undo {
119 struct sem_undo * proc_next; /* next entry on this process */
120 struct sem_undo * id_next; /* next entry on this semaphore set */
121 int semid; /* semaphore set identifier */
122 short * semadj; /* array of adjustments, one per semaphore */
123 };
124
125 /* sem_undo_list controls shared access to the list of sem_undo structures
126 * that may be shared among all a CLONE_SYSVSEM task group.
127 */
128 struct sem_undo_list {
129 atomic_t refcnt;
130 spinlock_t lock;
131 struct sem_undo *proc_list;
132 };
133
134 struct sysv_sem {
135 struct sem_undo_list *undo_list;
136 };
137
138 #ifdef CONFIG_SYSVIPC
139
140 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
141 extern void exit_sem(struct task_struct *tsk);
142
143 #else
144 static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
145 {
146 return 0;
147 }
148
149 static inline void exit_sem(struct task_struct *tsk)
150 {
151 return;
152 }
153 #endif
154
155 #endif /* __KERNEL__ */
156
157 #endif /* _LINUX_SEM_H */
158
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