[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>

arch/x86_64/ia32/ia32entry.S

@@ -695,4 +695,5 @@ ia32_sys_call_table:
 	.quad sys_splice
 	.quad sys_sync_file_range
 	.quad sys_tee
+	.quad compat_sys_vmsplice
 ia32_syscall_end:		

fs/compat.c

@@ -1317,6 +1317,26 @@ compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec, unsig
 	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.