Re: [PATCH RESEND] HID: fix error message in hid_open_report()

[Jiri Kosina <jikos@kernel.org>]

On Mon, 22 Jul 2019, Michał Mirosław wrote:

> On HID report descriptor parsing error the code displays bogus
> pointer instead of error offset (subtracts start=NULL from end).
> Make the message more useful by displaying correct error offset
> and include total buffer size for reference.
> 
> This was carried over from ancient times - "Fixed" commit just
> promoted the message from DEBUG to ERROR.
> 
> Cc: stable@vger.kernel.org
> Fixes: 8c3d52fc393b ("HID: make parser more verbose about parsing errors by default")
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
[ ... snip ... ]
> @@ -1230,7 +1232,8 @@ int hid_open_report(struct hid_device *device)
>  		}
>  	}
>  
> -	hid_err(device, "item fetching failed at offset %d\n", (int)(end - start));
> +	hid_err(device, "item fetching failed at offset %zu/%zu\n",
> +		size - (end - start), size);

Hi Michal,

thanks for the fix.

This causes:

drivers/hid/hid-core.c: In function ‘hid_open_report’:
drivers/hid/hid-core.c:1235:2: warning: format ‘%zu’ expects argument of type ‘size_t’, but argument 4 has type ‘unsigned int’ [-Wformat=]
  hid_err(device, "item fetching failed at offset %zu/%zu\n",
  ^

could you please fix that up and resubmit?

Thanks,

-- 
Jiri Kosina
SUSE Labs