[PATCH 0/10] use safer test on the result of find_first_zero_bit

David Laight David.Laight at ACULAB.COM
Wed Jun 4 09:46:17 UTC 2014


From: Julia Lawall
> On Wed, 4 Jun 2014, Geert Uytterhoeven wrote:
> 
> > Hi Julia,
> >
> > On Wed, Jun 4, 2014 at 11:07 AM, Julia Lawall <Julia.Lawall at lip6.fr> wrote:
> > > Find_first_zero_bit considers BITS_PER_LONG bits at a time, and thus may
> > > return a larger number than the maximum position argument if that position
> > > is not a multiple of BITS_PER_LONG.
> >
> > Shouldn't this be fixed in find_first_zero_bit() instead?
> 
> OK, I could do that as well.  Most of the callers currently test with >=.
> Should they be left as is, or changed to use ==?

Do we want to add an extra test to find_first_zero_bit() and effectively
slow down all the calls - especially those where the length is a
multiple of 8 (probably the most common).

Maybe the documented return code should be changed to allow for the
existing behaviour.

	David





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