[PATCH] usb: gadgetfs: return number of bytes on ep0 read request

[PATCH] usb: gadgetfs: return number of bytes on ep0 read request

[Thomas Faber]

A read from GadgetFS endpoint 0 during the data stage of a control
request would always return 0 on success (as returned by
wait_event_interruptible) despite having written data into the user
buffer.
This patch makes it correctly set the return value to the number of
bytes read.

Signed-off-by: Thomas Faber <thfabba@gmx.de>
---
 drivers/usb/gadget/inode.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index ae04266..4f18a0e 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -1043,6 +1043,8 @@ ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
 // FIXME don't call this with the spinlock held ...
 				if (copy_to_user (buf, dev->req->buf, len))
 					retval = -EFAULT;
+				else
+					retval = len;
 				clean_req (dev->gadget->ep0, dev->req);
 				/* NOTE userspace can't yet choose to stall */
 			}
-- 
1.7.3.4

Re: [PATCH] usb: gadgetfs: return number of bytes on ep0 read request

[Michal Nazarewicz]

On Fri, 02 Mar 2012 09:41:50 +0100, Thomas Faber <thfabba@gmx.de> wrote:
> A read from GadgetFS endpoint 0 during the data stage of a control
> request would always return 0 on success (as returned by
> wait_event_interruptible) despite having written data into the user
> buffer.
> This patch makes it correctly set the return value to the number of
> bytes read.
>
> Signed-off-by: Thomas Faber <thfabba@gmx.de>

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: stable@vger.kernel.org

> ---
>  drivers/usb/gadget/inode.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
> index ae04266..4f18a0e 100644
> --- a/drivers/usb/gadget/inode.c
> +++ b/drivers/usb/gadget/inode.c
> @@ -1043,6 +1043,8 @@ ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
>  // FIXME don't call this with the spinlock held ...
>  				if (copy_to_user (buf, dev->req->buf, len))
>  					retval = -EFAULT;
> +				else
> +					retval = len;
>  				clean_req (dev->gadget->ep0, dev->req);
>  				/* NOTE userspace can't yet choose to stall */
>  			}


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.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
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