On Thu, May 12, 2022 at 01:01:07PM +0000, David Laight wrote:> > +static inline int64_t sign_extend64(uint64_t value, int index)> > +{> > + int shift = 63 - index;> > + return (int64_t)(value << shift) >> shift;> > +}> > Shift of signed integers are UB.The kernel uses -fno-strict-overflow, all the signed UB is gone.