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
