From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [patch 1/2] xen-gntdev: return -EFAULT on copy_to_user failure Date: Fri, 25 Mar 2011 11:04:38 -0400 Message-ID: <20110325150438.GG27651@dumpdata.com> References: <20110319054434.GD2008@bicker> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20110319054434.GD2008@bicker> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Dan Carpenter Cc: Jeremy Fitzhardinge , kernel-janitors@vger.kernel.org, xen-devel@lists.xensource.com, virtualization@lists.linux-foundation.org List-Id: xen-devel@lists.xenproject.org On Sat, Mar 19, 2011 at 08:44:34AM +0300, Dan Carpenter wrote: > 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. Thank you. Will put it on rc1 train. > > 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]); > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel