src/ipc/semctl.c

   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 }