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Re: [PATCH] x86-64: Use IFUNC strncat inside libc.so
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org
- Date: Wed, 16 May 2018 11:08:53 -0300
- Subject: Re: [PATCH] x86-64: Use IFUNC strncat inside libc.so
- References: <20180516121856.GA12678@gmail.com>
On 16/05/2018 09:18, H.J. Lu wrote:
> Unlike i386, we can call hidden IFUNC functions inside libc.so since
> x86-64 PLT is always PIC.
>
> Tested on x86-64.
>
> Any comments?
>
LGTM.
>
> H.J.
> ---
> * sysdeps/x86_64/multiarch/strncat-c.c (STRNCAT_PRIMARY): Removed.
> Include <string/strncat.c>.
> * sysdeps/x86_64/multiarch/strncat.c (__strncat): New strong
> alias.
> (__GI___strncat): New hidden alias.
> ---
> sysdeps/x86_64/multiarch/strncat-c.c | 3 +--
> sysdeps/x86_64/multiarch/strncat.c | 5 +++++
> 2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/sysdeps/x86_64/multiarch/strncat-c.c b/sysdeps/x86_64/multiarch/strncat-c.c
> index db8ad9917c..93a7fab7ea 100644
> --- a/sysdeps/x86_64/multiarch/strncat-c.c
> +++ b/sysdeps/x86_64/multiarch/strncat-c.c
> @@ -1,3 +1,2 @@
> #define STRNCAT __strncat_sse2
> -#define STRNCAT_PRIMARY
> -#include "string/strncat.c"
> +#include <string/strncat.c>
> diff --git a/sysdeps/x86_64/multiarch/strncat.c b/sysdeps/x86_64/multiarch/strncat.c
> index 1267eb4972..841c165565 100644
> --- a/sysdeps/x86_64/multiarch/strncat.c
> +++ b/sysdeps/x86_64/multiarch/strncat.c
> @@ -27,4 +27,9 @@
> # include "ifunc-unaligned-ssse3.h"
>
> libc_ifunc_redirected (__redirect_strncat, strncat, IFUNC_SELECTOR ());
> +strong_alias (strncat, __strncat);
> +# ifdef SHARED
> +__hidden_ver1 (strncat, __GI___strncat, __redirect_strncat)
> + __attribute__((visibility ("hidden")));
> +# endif
> #endif
>