I wish that this could have been detected with static analysis...
On Tue, Oct 22, 2019 at 05:45:14PM +0200, Takashi Iwai wrote:
> diff --git a/sound/usb/validate.c b/sound/usb/validate.c
> index 3c8f73a0eb12..a5e584b60dcd 100644
> --- a/sound/usb/validate.c
> +++ b/sound/usb/validate.c
> @@ -75,7 +75,7 @@ static bool validate_processing_unit(const void *p,
>
> if (d->bLength < sizeof(*d))
^^^^^^^^^^^^^^^^^^^^^^^
So we know that d->bLength is >= 10.
> return false;
> - len = d->bLength < sizeof(*d) + d->bNrInPins;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Len is 1 or 0.
> + len = sizeof(*d) + d->bNrInPins;
> if (d->bLength < len)
^^^^^^^^^^^^^^^^
So this condition can't be false.
> return false;
But it just makes this return into dead code and we have a lot of dead
code paths in the kernel so it doesn't make sense to generate a warning.
... I don't know if I have a solution.
Maybe some day we will have a vim pluggin which will highlight all the
dead paths and someone would notice that it that way.
regards,
dan carpenter
