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 */ 23 struct 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. */ 38 struct 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. */ 45 union 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 53 struct 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 83 struct task_struct; 84 85 /* One semaphore structure for each semaphore in the system. */ 86 struct sem { 87 int semval; /* current value */ 88 int sempid; /* pid of last operation */ 89 struct list_head sem_pending; /* pending single-sop operations */ 90 }; 91 92 /* One sem_array data structure for each set of semaphores in the system. */ 93 struct sem_array { 94 struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */ 95 time_t sem_otime; /* last semop time */ 96 time_t sem_ctime; /* last change time */ 97 struct sem *sem_base; /* ptr to first semaphore in array */ 98 struct list_head sem_pending; /* pending operations to be processed */ 99 struct list_head list_id; /* undo requests on this array */ 100 int sem_nsems; /* no. of semaphores in array */ 101 int complex_count; /* pending complex operations */ 102 }; 103 104 /* One queue for each sleeping process in the system. */ 105 struct sem_queue { 106 struct list_head simple_list; /* queue of pending operations */ 107 struct list_head list; /* queue of pending operations */ 108 struct task_struct *sleeper; /* this process */ 109 struct sem_undo *undo; /* undo structure */ 110 int pid; /* process id of requesting process */ 111 int status; /* completion status of operation */ 112 struct sembuf *sops; /* array of pending operations */ 113 int nsops; /* number of operations */ 114 int alter; /* does the operation alter the array? */ 115 }; 116 117 /* Each task has a list of undo requests. They are executed automatically 118 * when the process exits. 119 */ 120 struct sem_undo { 121 struct list_head list_proc; /* per-process list: all undos from one process. */ 122 /* rcu protected */ 123 struct rcu_head rcu; /* rcu struct for sem_undo() */ 124 struct sem_undo_list *ulp; /* sem_undo_list for the process */ 125 struct list_head list_id; /* per semaphore array list: all undos for one array */ 126 int semid; /* semaphore set identifier */ 127 short * semadj; /* array of adjustments, one per semaphore */ 128 }; 129 130 /* sem_undo_list controls shared access to the list of sem_undo structures 131 * that may be shared among all a CLONE_SYSVSEM task group. 132 */ 133 struct sem_undo_list { 134 atomic_t refcnt; 135 spinlock_t lock; 136 struct list_head list_proc; 137 }; 138 139 struct sysv_sem { 140 struct sem_undo_list *undo_list; 141 }; 142 143 #ifdef CONFIG_SYSVIPC 144 145 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk); 146 extern void exit_sem(struct task_struct *tsk); 147 148 #else 149 static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) 150 { 151 return 0; 152 } 153 154 static inline void exit_sem(struct task_struct *tsk) 155 { 156 return; 157 } 158 #endif 159 160 #endif /* __KERNEL__ */ 161 162 #endif /* _LINUX_SEM_H */ 163