github.com/afumu/libc@v0.0.6/musl/src/ipc/shmctl.c (about)

     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  }