From 9d2be9287107695708e6aae5105a8a518a6cb4d0 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Sat, 8 Sep 2012 12:57:35 +0300
Subject: [PATCH] xen/privcmd: return -EFAULT on error

__copy_to_user() returns the number of bytes remaining to be copied but
we want to return a negative error code here.

Acked-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/xen/privcmd.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 3b162c656205c..ef6389580b8c7 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -389,8 +389,11 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version)
 		state.err      = err_array;
 		ret = traverse_pages(m.num, sizeof(xen_pfn_t),
 				     &pagelist, mmap_return_errors_v1, &state);
-	} else if (version == 2)
+	} else if (version == 2) {
 		ret = __copy_to_user(m.err, err_array, m.num * sizeof(int));
+		if (ret)
+			ret = -EFAULT;
+	}
 
 	/* If we have not had any EFAULT-like global errors then set the global
 	 * error to -ENOENT if necessary. */
-- 
2.39.5