[PATCH] aarch64: Don't define memchr/strlen when used in IFUNC [BZ #31777]

[H.J. Lu]

On Tue, May 21, 2024 at 10:23 AM Adhemerval Zanella Netto
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 21/05/24 11:37, H.J. Lu wrote:
> > Fix BZ #31777 by not defining memchr/strlen aliases when used in IFUNC.
> >
> > Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
> > ---
> >  sysdeps/aarch64/memchr.S | 3 +++
> >  sysdeps/aarch64/strlen.S | 3 +++
> >  2 files changed, 6 insertions(+)
> >
> > diff --git a/sysdeps/aarch64/memchr.S b/sysdeps/aarch64/memchr.S
> > index a9fa40519c..6aa93a344b 100644
> > --- a/sysdeps/aarch64/memchr.S
> > +++ b/sysdeps/aarch64/memchr.S
> > @@ -28,6 +28,7 @@
> >
> >  #ifndef MEMCHR
> >  # define MEMCHR __memchr
> > +# define NEED_memchr
> >  #endif
> >
> >  #define srcin                x0
> > @@ -124,5 +125,7 @@ L(nomatch):
> >       ret
> >
> >  END (MEMCHR)
> > +#ifdef NEED_memchr
> >  weak_alias (MEMCHR, memchr)
> > +#endif
> >  libc_hidden_builtin_def (memchr)
>
> The aarch64 memchr_generic.S already redefine libc_hidden_builtin_def to
> avoid a similar issue, so I think it would be better to fix it on the
> same place (and it is similar to how other ports do):

I am dropping my patch.

> diff --git a/sysdeps/aarch64/multiarch/memchr_generic.S b/sysdeps/aarch64/multiarch/memchr_generic.S
> index 0ed5811745..8d554275ba 100644
> --- a/sysdeps/aarch64/multiarch/memchr_generic.S
> +++ b/sysdeps/aarch64/multiarch/memchr_generic.S
> @@ -24,6 +24,9 @@
>  # undef libc_hidden_builtin_def
>  # define libc_hidden_builtin_def(name)
>
> +# undef weak_alias
> +# define weak_alias(a, b)
> +
>  /* Add a hidden definition for use within libc.so.  */
>  # ifdef SHARED
>         .globl __GI_memchr; __GI_memchr = __memchr_generic
>
> > diff --git a/sysdeps/aarch64/strlen.S b/sysdeps/aarch64/strlen.S
> > index ab2a576cdb..ef8db695e6 100644
> > --- a/sysdeps/aarch64/strlen.S
> > +++ b/sysdeps/aarch64/strlen.S
> > @@ -26,6 +26,7 @@
> >
> >  #ifndef STRLEN
> >  # define STRLEN __strlen
> > +# define NEED_strlen
> >  #endif
> >
> >  #define srcin                x0
> > @@ -89,5 +90,7 @@ L(loop_end):
> >       ret
> >
> >  END (STRLEN)
> > +#ifdef NEED_strlen
> >  weak_alias (STRLEN, strlen)
> > +#endif
> >  libc_hidden_builtin_def (strlen)



-- 
H.J.