[PATCH] x86_64: Add compat_sys_vmsplice and use it in x86-64

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/compat.c b/fs/compat.c
index 2e32bd3..3f3e8f4 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1317,6 +1317,26 @@
 	return ret;
 }
 
+asmlinkage long
+compat_sys_vmsplice(int fd, const struct compat_iovec __user *iov32,
+		    unsigned int nr_segs, unsigned int flags)
+{
+	unsigned i;
+	struct iovec *iov;
+	if (nr_segs >= UIO_MAXIOV)
+		return -EINVAL;
+	iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec));
+	for (i = 0; i < nr_segs; i++) {
+		struct compat_iovec v;
+		if (get_user(v.iov_base, &iov32[i].iov_base) ||
+		    get_user(v.iov_len, &iov32[i].iov_len) ||
+		    put_user(compat_ptr(v.iov_base), &iov[i].iov_base) ||
+		    put_user(v.iov_len, &iov[i].iov_len))
+			return -EFAULT;
+	}
+	return sys_vmsplice(fd, iov, nr_segs, flags);
+}
+
 /*
  * Exactly like fs/open.c:sys_open(), except that it doesn't set the
  * O_LARGEFILE flag.