shmid_ds
long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
struct shmid_ds;
asmlinkage long sys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
static long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf, int version)
SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
struct shmid_ds out;
struct shmid_ds tbuf_old;
(struct shmid_ds __user *) ptr);