On Mon, 28 Oct 2019 15:34:06 +0100, Dan Carpenter wrote:
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.
That'd be awesome :) Of even a simple checker code that can run in the git commit hook should suffice for careless maintainers like me.
thanks,
Takashi