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#define SEM_STAT_ANY 20
  23
  24/* Obsolete, used only for backwards compatibility and libc5 compiles */
  25struct semid_ds {
  26        struct ipc_perm sem_perm;               /* permissions .. see ipc.h */
  27        __kernel_old_time_t sem_otime;          /* last semop time */
  28        __kernel_old_time_t sem_ctime;          /* create/last semctl() time */
  29        struct sem      *sem_base;              /* ptr to first semaphore in array */
  30        struct sem_queue *sem_pending;          /* pending operations to be processed */
  31        struct sem_queue **sem_pending_last;    /* last pending operation */
  32        struct sem_undo *undo;                  /* undo requests on this array */
  33        unsigned short  sem_nsems;              /* no. of semaphores in array */
  34};
  35
  36/* Include the definition of semid64_ds */
  37#include <asm/sembuf.h>
  38
  39/* semop system calls takes an array of these. */
  40struct sembuf {
  41        unsigned short  sem_num;        /* semaphore index in array */
  42        short           sem_op;         /* semaphore operation */
  43        short           sem_flg;        /* operation flags */
  44};
  45
  46/* arg for semctl system calls. */
  47union semun {
  48        int val;                        /* value for SETVAL */
  49        struct semid_ds __user *buf;    /* buffer for IPC_STAT & IPC_SET */
  50        unsigned short __user *array;   /* array for GETALL & SETALL */
  51        struct seminfo __user *__buf;   /* buffer for IPC_INFO */
  52        void __user *__pad;
  53};
  54
  55struct  seminfo {
  56        int semmap;
  57        int semmni;
  58        int semmns;
  59        int semmnu;
  60        int semmsl;
  61        int semopm;
  62        int semume;
  63        int semusz;
  64        int semvmx;
  65        int semaem;
  66};
  67
  68/*
  69 * SEMMNI, SEMMSL and SEMMNS are default values which can be
  70 * modified by sysctl.
  71 * The values has been chosen to be larger than necessary for any
  72 * known configuration.
  73 *
  74 * SEMOPM should not be increased beyond 1000, otherwise there is the
  75 * risk that semop()/semtimedop() fails due to kernel memory fragmentation when
  76 * allocating the sop array.
  77 */
  78
  79
  80#define SEMMNI  32000           /* <= IPCMNI  max # of semaphore identifiers */
  81#define SEMMSL  32000           /* <= INT_MAX max num of semaphores per id */
  82#define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
  83#define SEMOPM  500             /* <= 1 000 max num of ops per semop call */
  84#define SEMVMX  32767           /* <= 32767 semaphore maximum value */
  85#define SEMAEM  SEMVMX          /* adjust on exit max value */
  86
  87/* unused */
  88#define SEMUME  SEMOPM          /* max num of undo entries per process */
  89#define SEMMNU  SEMMNS          /* num of undo structures system wide */
  90#define SEMMAP  SEMMNS          /* # of entries in semaphore map */
  91#define SEMUSZ  20              /* sizeof struct sem_undo */
  92
  93
  94#endif /* _UAPI_LINUX_SEM_H */
  95