Re: [PATCH 0/1] Slightly relax the type checking done by min() and max().

From: Andy Shevchenko
Date: Fri Nov 25 2022 - 10:20:49 EST


On Fri, Nov 25, 2022 at 03:00:40PM +0000, David Laight wrote:
> The min() and max() defines include a type check to avoid the unexpected
> behaviour when a negative value is compared against and unsigned value.
> However a lot of code hits this check and uses min_t() to avoid the error.
> Many of these are just plain wrong.
>
> Those casting to u8 or u16 are particularly suspect, eg:
> drivers/usb/misc/usb251xb.c:528:
> hub->max_current_sp = min_t(u8, property_u32 / 2000, 50);

I don't buy this. What's exactly wrong with this code?

--
With Best Regards,
Andy Shevchenko