[PATCH v1 12/23] x86: Fix fallback for wcsncmp_avx2 in strcmp-avx2.S [BZ #28896]

[Noah Goldstein]

On Thu, Mar 24, 2022 at 2:00 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Wed, Mar 23, 2022 at 3:01 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
> >
> > Overflow case for __wcsncmp_avx2_rtm should be __wcscmp_avx2_rtm not
> > __wcscmp_avx2.
> >
> > All string/memory tests pass.
> > ---
> >  sysdeps/x86_64/multiarch/strcmp-avx2.S | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > index 52ff5ad724..86a86b68e3 100644
> > --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S
> > @@ -122,7 +122,7 @@ ENTRY(STRCMP)
> >            are cases where length is large enough that it can never be a
> >            bound on valid memory so just use wcscmp.  */
> >         shrq    $56, %rcx
> > -       jnz     __wcscmp_avx2
> > +       jnz     OVERFLOW_STRCMP
> >
> >         leaq    (, %rdx, 4), %rdx
> >  #  endif
> > --
> > 2.25.1
> >
>
> Isn't it a bug?  Is there a glibc bug? Should this also be fixed on release
> branches?

It is bug but no need for backport.
>
> --
> H.J.