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1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _UAPI_LINUX_SEM_H
3 #define _UAPI_LINUX_SEM_H
4 
5 #include <linux/ipc.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;		/* create/last semctl() 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 /*
68  * SEMMNI, SEMMSL and SEMMNS are default values which can be
69  * modified by sysctl.
70  * The values has been chosen to be larger than necessary for any
71  * known configuration.
72  *
73  * SEMOPM should not be increased beyond 1000, otherwise there is the
74  * risk that semop()/semtimedop() fails due to kernel memory fragmentation when
75  * allocating the sop array.
76  */
77 
78 
79 #define SEMMNI  32000           /* <= IPCMNI  max # of semaphore identifiers */
80 #define SEMMSL  32000           /* <= INT_MAX max num of semaphores per id */
81 #define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
82 #define SEMOPM  500	        /* <= 1 000 max num of ops per semop call */
83 #define SEMVMX  32767           /* <= 32767 semaphore maximum value */
84 #define SEMAEM  SEMVMX          /* adjust on exit max value */
85 
86 /* unused */
87 #define SEMUME  SEMOPM          /* max num of undo entries per process */
88 #define SEMMNU  SEMMNS          /* num of undo structures system wide */
89 #define SEMMAP  SEMMNS          /* # of entries in semaphore map */
90 #define SEMUSZ  20		/* sizeof struct sem_undo */
91 
92 
93 #endif /* _UAPI_LINUX_SEM_H */
94