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 82 struct task_struct; 83 84 /* One semaphore structure for each semaphore in the system. */ 85 struct sem { 86 int semval; /* current value */ 87 int sempid; /* pid of last operation */ 88 }; 89 90 /* One sem_array data structure for each set of semaphores in the system. */ 91 struct sem_array { 92 struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */ 93 int sem_id; 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 sem_queue *sem_pending; /* pending operations to be processed */ 98 struct sem_queue **sem_pending_last; /* last pending operation */ 99 struct sem_undo *undo; /* undo requests on this array */ 100 unsigned long sem_nsems; /* no. of semaphores in array */ 101 }; 102 103 /* One queue for each sleeping process in the system. */ 104 struct sem_queue { 105 struct sem_queue * next; /* next entry in the queue */ 106 struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */ 107 struct task_struct* sleeper; /* this process */ 108 struct sem_undo * undo; /* undo structure */ 109 int pid; /* process id of requesting process */ 110 int status; /* completion status of operation */ 111 struct sem_array * sma; /* semaphore array for operations */ 112 int id; /* internal sem id */ 113 struct sembuf * sops; /* array of pending operations */ 114 int nsops; /* number of operations */ 115 int alter; /* does the operation alter the array? */ 116 }; 117 118 /* Each task has a list of undo requests. They are executed automatically 119 * when the process exits. 120 */ 121 struct sem_undo { 122 struct sem_undo * proc_next; /* next entry on this process */ 123 struct sem_undo * id_next; /* next entry on this semaphore set */ 124 int semid; /* semaphore set identifier */ 125 short * semadj; /* array of adjustments, one per semaphore */ 126 }; 127 128 /* sem_undo_list controls shared access to the list of sem_undo structures 129 * that may be shared among all a CLONE_SYSVSEM task group. 130 */ 131 struct sem_undo_list { 132 atomic_t refcnt; 133 spinlock_t lock; 134 struct sem_undo *proc_list; 135 }; 136 137 struct sysv_sem { 138 struct sem_undo_list *undo_list; 139 }; 140 141 #ifdef CONFIG_SYSVIPC 142 143 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk); 144 extern void exit_sem(struct task_struct *tsk); 145 146 #else 147 static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) 148 { 149 return 0; 150 } 151 152 static inline void exit_sem(struct task_struct *tsk) 153 { 154 return; 155 } 156 #endif 157 158 #endif /* __KERNEL__ */ 159 160 #endif /* _LINUX_SEM_H */ 161
