include/uapi/linux/sem.h

   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 */