Re: [PATCH] USB: serial: ti_usb_3410_5052: Replace zero-length array with flexible-array member

From: Gustavo A. R. Silva
Date: Wed Feb 12 2020 - 14:25:06 EST




On 2/12/20 01:59, Johan Hovold wrote:
> On Tue, Feb 11, 2020 at 05:24:20PM -0600, Gustavo A. R. Silva wrote:
>> The current codebase makes use of the zero-length array language
>> extension to the C90 standard, but the preferred mechanism to declare
>> variable-length types such as these ones is a flexible array member[1][2],
>> introduced in C99:
>>
>> struct foo {
>> int stuff;
>> struct boo array[];
>> };
>>
>> By making use of the mechanism above, we will get a compiler warning
>> in case the flexible array does not occur last in the structure, which
>> will help us prevent some kind of undefined behavior bugs from being
>> inadvertenly introduced[3] to the codebase from now on.
>>
>> This issue was found with the help of Coccinelle.
>
> Same here, the scripts may need to be updated as you missed a couple of
> instances:
>
> $ git grep '\[0\];' drivers/usb/serial
> ...
> drivers/usb/serial/io_usbvend.h: __u8 Data[0]; // Data starts here
> drivers/usb/serial/io_usbvend.h: __u8 Data[0]; // Download starts here
> ...
>
> Could you replace these as well so that is done in one patch per
> subsystem?
>

Sure thing. I'll do that.

Thanks for the feedback.
--
Gustavo