Re: [PATCH] usb/gadget: function fs req_match endpoint address fix

[Greg KH <greg@kroah.com>]

On Tue, Oct 03, 2023 at 03:11:03PM -0700, linux-dev@sensoray.com wrote:
> From: Dean Anderson <linux-dev@sensoray.com>
> 
> Fixes f_fs.c handling USB_RECIP_ENDPOINT request types incorrectly for
> endpoints not belonging to it. f_fs.c needs to distinguish between IN
> and OUT endpoints, not just the endpoint number. Otherwise, f_fs may
> handle endpoints belonging to other functions. This occurs in the
> gadget/composite.c composite_setup function in the req_match callback.
> 
> Signed-off-by: Dean Anderson <linux-dev@sensoray.com>

What commit id does this fix?

> ---
>  drivers/usb/gadget/function/f_fs.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
> index c727cb5de871..fb95ca4aa025 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -71,7 +71,7 @@ struct ffs_function {
>  	struct ffs_data			*ffs;
>  
>  	struct ffs_ep			*eps;
> -	u8				eps_revmap[16];
> +	u8				eps_revmap[32]; /* 16 in endpoints, 16 out endpoints*/

Can't this be two separate arrays so you don't have to do fun masks to
pick out which is an in and which is an out?

>  	short				*interfaces_nums;
>  
>  	struct usb_function		function;
> @@ -2847,6 +2847,7 @@ static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
>  		struct usb_ep *ep;
>  		u8 bEndpointAddress;
>  		u16 wMaxPacketSize;
> +		u8 addr;
>  
>  		/*
>  		 * We back up bEndpointAddress because autoconfig overwrites
> @@ -2870,8 +2871,9 @@ static int __ffs_func_bind_do_descs(enum ffs_entity_type type, u8 *valuep,
>  
>  		ffs_ep->ep  = ep;
>  		ffs_ep->req = req;
> -		func->eps_revmap[ds->bEndpointAddress &
> -				 USB_ENDPOINT_NUMBER_MASK] = idx + 1;
> +		addr = ((ds->bEndpointAddress & USB_ENDPOINT_DIR_MASK) >> 3)
> +			| (ds->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
> +		func->eps_revmap[addr] = idx + 1;
>  		/*
>  		 * If we use virtual address mapping, we restore
>  		 * original bEndpointAddress value.
> @@ -3403,7 +3405,9 @@ static void ffs_func_resume(struct usb_function *f)
>  
>  static int ffs_func_revmap_ep(struct ffs_function *func, u8 num)
>  {
> -	num = func->eps_revmap[num & USB_ENDPOINT_NUMBER_MASK];
> +	u8 addr = ((num & USB_ENDPOINT_DIR_MASK) >> 3)
> +		| (num & USB_ENDPOINT_NUMBER_MASK);
> +	num = func->eps_revmap[addr];

That's messy, again, 2 arrays would make this much simpler I think?

thanks,

greg k-h