On 07/31/2018 11:09 PM, Kees Cook wrote: > From: Jason Gunthorpe <j...@mellanox.com> > > Add shift_overflow() helper to assist driver authors in ensuring that > shift operations don't cause overflows or other odd conditions. > > Signed-off-by: Jason Gunthorpe <j...@mellanox.com> > Signed-off-by: Leon Romanovsky <leo...@mellanox.com> > [kees: tweaked comments and commit log, dropped unneeded assignment] > Signed-off-by: Kees Cook <keesc...@chromium.org> > --- > include/linux/overflow.h | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/include/linux/overflow.h b/include/linux/overflow.h > index 8712ff70995f..69fc366ce865 100644 > --- a/include/linux/overflow.h > +++ b/include/linux/overflow.h > @@ -202,6 +202,37 @@ > > #endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */ > > +/** check_shift_overflow() - Calculate a left-shifted value and check > overflow > + * > + * @a: Value to be shifted > + * @b: How many bits left to shift > + * @d: Pointer to where to store the result > + * > + * Computes *@d = (@a << @s) > + *
missed @b [again] -- ~Randy
