1 #ifndef _LINUX_SEM_H 2 #define _LINUX_SEM_H 3 4 #include <linux/ipc.h> 5 #include <asm/atomic.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 */ 24 struct 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; /* last change 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. */ 39 struct 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. */ 46 union 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 54 struct 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 #define SEMMNI 128 /* <= IPCMNI max # of semaphore identifiers */ 68 #define SEMMSL 250 /* <= 8 000 max num of semaphores per id */ 69 #define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */ 70 #define SEMOPM 32 /* <= 1 000 max num of ops per semop call */ 71 #define SEMVMX 32767 /* <= 32767 semaphore maximum value */ 72 #define SEMAEM SEMVMX /* adjust on exit max value */ 73 74 /* unused */ 75 #define SEMUME SEMOPM /* max num of undo entries per process */ 76 #define SEMMNU SEMMNS /* num of undo structures system wide */ 77 #define SEMMAP SEMMNS /* # of entries in semaphore map */ 78 #define SEMUSZ 20 /* sizeof struct sem_undo */ 79 80 #ifdef __KERNEL__ 81 82 /* One semaphore structure for each semaphore in the system. */ 83 struct sem { 84 int semval; /* current value */ 85 int sempid; /* pid of last operation */ 86 }; 87 88 /* One sem_array data structure for each set of semaphores in the system. */ 89 struct sem_array { 90 struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */ 91 time_t sem_otime; /* last semop time */ 92 time_t sem_ctime; /* last change time */ 93 struct sem *sem_base; /* ptr to first semaphore in array */ 94 struct sem_queue *sem_pending; /* pending operations to be processed */ 95 struct sem_queue **sem_pending_last; /* last pending operation */ 96 struct sem_undo *undo; /* undo requests on this array */ 97 unsigned long sem_nsems; /* no. of semaphores in array */ 98 }; 99 100 /* One queue for each sleeping process in the system. */ 101 struct sem_queue { 102 struct sem_queue * next; /* next entry in the queue */ 103 struct sem_queue ** prev; /* previous entry in the queue, *(q->prev) == q */ 104 struct task_struct* sleeper; /* this process */ 105 struct sem_undo * undo; /* undo structure */ 106 int pid; /* process id of requesting process */ 107 int status; /* completion status of operation */ 108 struct sem_array * sma; /* semaphore array for operations */ 109 int id; /* internal sem id */ 110 struct sembuf * sops; /* array of pending operations */ 111 int nsops; /* number of operations */ 112 int alter; /* does the operation alter the array? */ 113 }; 114 115 /* Each task has a list of undo requests. They are executed automatically 116 * when the process exits. 117 */ 118 struct sem_undo { 119 struct sem_undo * proc_next; /* next entry on this process */ 120 struct sem_undo * id_next; /* next entry on this semaphore set */ 121 int semid; /* semaphore set identifier */ 122 short * semadj; /* array of adjustments, one per semaphore */ 123 }; 124 125 /* sem_undo_list controls shared access to the list of sem_undo structures 126 * that may be shared among all a CLONE_SYSVSEM task group. 127 */ 128 struct sem_undo_list { 129 atomic_t refcnt; 130 spinlock_t lock; 131 struct sem_undo *proc_list; 132 }; 133 134 struct sysv_sem { 135 struct sem_undo_list *undo_list; 136 }; 137 138 #ifdef CONFIG_SYSVIPC 139 140 extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk); 141 extern void exit_sem(struct task_struct *tsk); 142 143 #else 144 static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) 145 { 146 return 0; 147 } 148 149 static inline void exit_sem(struct task_struct *tsk) 150 { 151 return; 152 } 153 #endif 154 155 #endif /* __KERNEL__ */ 156 157 #endif /* _LINUX_SEM_H */ 158