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

[dean@sensoray.com]

On 2023-10-05 02:20, Greg KH wrote:
> 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?

It's out of date. I'll resubmit with the suggested changes.

> 
>> ---
>>  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?

It's similar to the approach in composite.c. v6.6-rc4, line 1013, but 
yes 2 arrays would be simpler.

BTW, should composite.c at least get rid of the magic numbers?

composite.c commit 8a749fd1a8720d4619c91c8b6e7528c0a355c0aa
line: 1013

addr = ((ep->bEndpointAddress & 0x80) >> 3)
      |  (ep->bEndpointAddress & 0x0f);

> 
> thanks,
> 
> greg k-h

Thanks,

Dean A