semctl.c raw

   1  #include <sys/sem.h>
   2  #include <stdarg.h>
   3  #include <endian.h>
   4  #include "syscall.h"
   5  #include "ipc.h"
   6  
   7  #if __BYTE_ORDER != __BIG_ENDIAN
   8  #undef SYSCALL_IPC_BROKEN_MODE
   9  #endif
  10  
  11  union semun {
  12  	int val;
  13  	struct semid_ds *buf;
  14  	unsigned short *array;
  15  };
  16  
  17  int semctl(int id, int num, int cmd, ...)
  18  {
  19  	union semun arg = {0};
  20  	va_list ap;
  21  	switch (cmd & ~IPC_TIME64) {
  22  	case SETVAL: case GETALL: case SETALL: case IPC_SET:
  23  	case IPC_INFO: case SEM_INFO:
  24  	case IPC_STAT & ~IPC_TIME64:
  25  	case SEM_STAT & ~IPC_TIME64:
  26  	case SEM_STAT_ANY & ~IPC_TIME64:
  27  		va_start(ap, cmd);
  28  		arg = va_arg(ap, union semun);
  29  		va_end(ap);
  30  	}
  31  #if IPC_TIME64
  32  	struct semid_ds out, *orig;
  33  	if (cmd&IPC_TIME64) {
  34  		out = (struct semid_ds){0};
  35  		orig = arg.buf;
  36  		arg.buf = &out;
  37  	}
  38  #endif
  39  #ifdef SYSCALL_IPC_BROKEN_MODE
  40  	struct semid_ds tmp;
  41  	if (cmd == IPC_SET) {
  42  		tmp = *arg.buf;
  43  		tmp.sem_perm.mode *= 0x10000U;
  44  		arg.buf = &tmp;
  45  	}
  46  #endif
  47  #ifndef SYS_ipc
  48  	int r = __syscall(SYS_semctl, id, num, IPC_CMD(cmd), arg.buf);
  49  #else
  50  	int r = __syscall(SYS_ipc, IPCOP_semctl, id, num, IPC_CMD(cmd), &arg.buf);
  51  #endif
  52  #ifdef SYSCALL_IPC_BROKEN_MODE
  53  	if (r >= 0) switch (cmd | IPC_TIME64) {
  54  	case IPC_STAT:
  55  	case SEM_STAT:
  56  	case SEM_STAT_ANY:
  57  		arg.buf->sem_perm.mode >>= 16;
  58  	}
  59  #endif
  60  #if IPC_TIME64
  61  	if (r >= 0 && (cmd&IPC_TIME64)) {
  62  		arg.buf = orig;
  63  		*arg.buf = out;
  64  		IPC_HILO(arg.buf, sem_otime);
  65  		IPC_HILO(arg.buf, sem_ctime);
  66  	}
  67  #endif
  68  	return __syscall_ret(r);
  69  }
  70