LXR linux/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 */
  24struct 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. */
  39struct 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. */
  46union 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
  54struct  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