1#ifndef _LINUX_SEM_H 2#define _LINUX_SEM_H 3 4#include <linux/ipc.h> 5 6/* semop flags */ 7#define SEM_UNDO 0x1000 /* undo the operation on exit */ 8 9/* semctl Command Definitions. */ 10#define GETPID 11 /* get sempid */ 11#define GETVAL 12 /* get semval */ 12#define GETALL 13 /* get all semval's */ 13#define GETNCNT 14 /* get semncnt */ 14#define GETZCNT 15 /* get semzcnt */ 15#define SETVAL 16 /* set semval */ 16#define SETALL 17 /* set all semval's */ 17 18/* ipcs ctl cmds */ 19#define SEM_STAT 18 20#define SEM_INFO 19 21 22/* Obsolete, used only for backwards compatibility and libc5 compiles */ 23struct semid_ds { 24 struct ipc_perm sem_perm; /* permissions .. see ipc.h */ 25 __kernel_time_t sem_otime; /* last semop time */ 26 __kernel_time_t sem_ctime; /* last change time */ 27 struct sem *sem_base; /* ptr to first semaphore in array */ 28 struct sem_queue *sem_pending; /* pending operations to be processed */ 29 struct sem_queue **sem_pending_last; /* last pending operation */ 30 struct sem_undo *undo; /* undo requests on this array */ 31 unsigned short sem_nsems; /* no. of semaphores in array */ 32}; 33 34/* Include the definition of semid64_ds */ 35#include <asm/sembuf.h> 36 37/* semop system calls takes an array of these. */ 38struct sembuf { 39 unsigned short sem_num; /* semaphore index in array */ 40 short sem_op; /* semaphore operation */ 41 short sem_flg; /* operation flags */ 42}; 43 44/* arg for semctl system calls. */ 45union semun { 46 int val; /* value for SETVAL */ 47 struct semid_ds __user *buf; /* buffer for IPC_STAT & IPC_SET */ 48 unsigned short __user *array; /* array for GETALL & SETALL */ 49 struct seminfo __user *__buf; /* buffer for IPC_INFO */ 50 void __user *__pad; 51}; 52 53struct seminfo { 54 int semmap; 55 int semmni; 56 int semmns; 57 int semmnu; 58 int semmsl; 59 int semopm; 60 int semume; 61 int semusz; 62 int semvmx; 63 int semaem; 64}; 65 66#define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */ 67#define SEMMSL 250 /* <= 8 000 max num of semaphores per id */ 68#define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */ 69#define SEMOPM 32 /* <= 1 000 max num of ops per semop call */ 70#define SEMVMX 32767 /* <= 32767 semaphore maximum value */ 71#define SEMAEM SEMVMX /* adjust on exit max value */ 72 73/* unused */ 74#define SEMUME SEMOPM /* max num of undo entries per process */ 75#define SEMMNU SEMMNS /* num of undo structures system wide */ 76#define SEMMAP SEMMNS /* # of entries in semaphore map */ 77#define SEMUSZ 20 /* sizeof struct sem_undo */ 78 79#ifdef __KERNEL__ 80#include <asm/atomic.h> 81#include <linux/rcupdate.h> 82 83struct task_struct; 84 85/* One semaphore structure for each semaphore in the system. */ 86struct sem { 87 int semval; /* current value */ 88 int sempid; /* pid of last operation */ 89}; 90 91/* One sem_array data structure for each set of semaphores in the system. */ 92struct sem_array { 93 struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */ 94 time_t sem_otime; /* last semop time */ 95 time_t sem_ctime; /* last change time */ 96 struct sem *sem_base; /* ptr to first semaphore in array */ 97 struct list_head sem_pending; /* pending operations to be processed */ 98 struct list_head list_id; /* undo requests on this array */ 99 unsigned long sem_nsems; /* no. of semaphores in array */ 100}; 101 102/* One queue for each sleeping process in the system. */ 103struct sem_queue { 104 struct list_head list; /* queue of pending operations */ 105 struct task_struct *sleeper; /* this process */ 106 struct sem_undo *undo; /* undo structure */ 107 int pid; /* process id of requesting process */ 108 int status; /* completion status of operation */ 109 struct sembuf *sops; /* array of pending operations */ 110 int nsops; /* number of operations */ 111 int alter; /* does the operation alter the array? */ 112}; 113 114/* Each task has a list of undo requests. They are executed automatically 115 * when the process exits. 116 */ 117struct sem_undo { 118 struct list_head list_proc; /* per-process list: all undos from one process. */ 119 /* rcu protected */ 120 struct rcu_head rcu; /* rcu struct for sem_undo() */ 121 struct sem_undo_list *ulp; /* sem_undo_list for the process */ 122 struct list_head list_id; /* per semaphore array list: all undos for one array */ 123 int semid; /* semaphore set identifier */ 124 short * semadj; /* array of adjustments, one per semaphore */ 125}; 126 127/* sem_undo_list controls shared access to the list of sem_undo structures 128 * that may be shared among all a CLONE_SYSVSEM task group. 129 */ 130struct sem_undo_list { 131 atomic_t refcnt; 132 spinlock_t lock; 133 struct list_head list_proc; 134}; 135 136struct sysv_sem { 137 struct sem_undo_list *undo_list; 138}; 139 140#ifdef CONFIG_SYSVIPC 141 142extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk); 143extern void exit_sem(struct task_struct *tsk); 144 145#else 146static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) 147{ 148 return 0; 149} 150 151static inline void exit_sem(struct task_struct *tsk) 152{ 153 return; 154} 155#endif 156 157#endif /* __KERNEL__ */ 158 159#endif /* _LINUX_SEM_H */ 160