libc-top-half/musl/src/ipc/shmctl.c

   1 #include <sys/shm.h>
   2 #include <endian.h>
   3 #include "syscall.h"
   4 #include "ipc.h"
   5
   6 #if __BYTE_ORDER != __BIG_ENDIAN
   7 #undef SYSCALL_IPC_BROKEN_MODE
   8 #endif
   9
  10 int shmctl(int id, int cmd, struct shmid_ds *buf)
  11 {
  12 #if IPC_TIME64
  13         struct shmid_ds out, *orig;
  14         if (cmd&IPC_TIME64) {
  15                 out = (struct shmid_ds){0};
  16                 orig = buf;
  17                 buf = &out;
  18         }
  19 #endif
  20 #ifdef SYSCALL_IPC_BROKEN_MODE
  21         struct shmid_ds tmp;
  22         if (cmd == IPC_SET) {
  23                 tmp = *buf;
  24                 tmp.shm_perm.mode *= 0x10000U;
  25                 buf = &tmp;
  26         }
  27 #endif
  28 #ifndef SYS_ipc
  29         int r = __syscall(SYS_shmctl, id, IPC_CMD(cmd), buf);
  30 #else
  31         int r = __syscall(SYS_ipc, IPCOP_shmctl, id, IPC_CMD(cmd), 0, buf, 0);
  32 #endif
  33 #ifdef SYSCALL_IPC_BROKEN_MODE
  34         if (r >= 0) switch (cmd | IPC_TIME64) {
  35         case IPC_STAT:
  36         case SHM_STAT:
  37         case SHM_STAT_ANY:
  38                 buf->shm_perm.mode >>= 16;
  39         }
  40 #endif
  41 #if IPC_TIME64
  42         if (r >= 0 && (cmd&IPC_TIME64)) {
  43                 buf = orig;
  44                 *buf = out;
  45                 IPC_HILO(buf, shm_atime);
  46                 IPC_HILO(buf, shm_dtime);
  47                 IPC_HILO(buf, shm_ctime);
  48         }
  49 #endif
  50         return __syscall_ret(r);
  51 }