From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Sat, 19 Mar 2011 05:44:34 +0000 Subject: [patch 1/2] xen-gntdev: return -EFAULT on copy_to_user failure Message-Id: <20110319054434.GD2008@bicker> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jeremy Fitzhardinge Cc: kernel-janitors@vger.kernel.org, xen-devel@lists.xensource.com, virtualization@lists.linux-foundation.org, Konrad Rzeszutek Wilk copy_to_user() returns the amount of data remaining to be copied. We want to return a negative error code here. The upper layers just call WARN_ON() if we return non-zero so this doesn't change the behavior. But returning -EFAULT is still cleaner. Signed-off-by: Dan Carpenter diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 017ce60..b0f9e8f 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -273,7 +273,7 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages) map->vma->vm_start + map->notify.addr; err = copy_to_user(tmp, &err, 1); if (err) - return err; + return -EFAULT; map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE; } else if (pgno >= offset && pgno < offset + pages) { uint8_t *tmp = kmap(map->pages[pgno]);