Re: [PATCH 03/11] libio: Add fortify wrapper for internal __snprintf

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 09/02/24 12:25, Florian Weimer wrote:
> ---
>  debug/snprintf_chk.c  | 1 +
>  include/bits/stdio2.h | 9 +++++++++
>  include/stdio.h       | 1 +
>  3 files changed, 11 insertions(+)
> 
> diff --git a/debug/snprintf_chk.c b/debug/snprintf_chk.c
> index 995d805f5d..ea02efec3e 100644
> --- a/debug/snprintf_chk.c
> +++ b/debug/snprintf_chk.c
> @@ -40,4 +40,5 @@ ___snprintf_chk (char *s, size_t maxlen, int flag, size_t slen,
>  
>    return ret;
>  }
> +ldbl_hidden_def (___snprintf_chk, __snprintf_chk)
>  ldbl_strong_alias (___snprintf_chk, __snprintf_chk)

I am seeing a build failure on powerpc64le with config options 
--enable-stack-protector=all --enable-tunables=yes --enable-bind-now=yes 
--enable-profile=yes --enable-fortify-source=2 --enable-hardcoded-path-in-tests:

powerpc64le-glibc-linux-gnu-gcc gconv_conf.c -c -std=gnu11 -fgnu89-inline  -g -O2 -Wall -Wwrite-strings -Wundef -Werror -fmerge-all-constants -frounding-math -fstack-protector-all -fno-common -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=2 -Wstrict-prototypes -Wold-style-definition -fmath-errno  -mabi=ieeelongdouble -Wno-psabi -mno-gnu-attribute -mlong-double-128  -fPIE [....]
In file included from gconv_conf.c:26:
../include/stdio.h:65:1: error: ‘asm’ declaration ignored due to conflict with previous rename [-Werror=pragmas]
   65 | stdio_hidden_ldbl_proto (__, snprintf_chk)
      | ^~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

All other ABIs build fine.

> diff --git a/include/bits/stdio2.h b/include/bits/stdio2.h
> index 6d7cf4306f..fb909c21ee 100644
> --- a/include/bits/stdio2.h
> +++ b/include/bits/stdio2.h
> @@ -1 +1,10 @@
>  #include <libio/bits/stdio2.h>
> +
> +__fortify_function int
> +__NTH (__snprintf (char *__restrict __s, size_t __n,
> +                   const char *__restrict __fmt, ...))
> +{
> +  return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
> +				   __glibc_objsize (__s), __fmt,
> +				   __va_arg_pack ());
> +}
> diff --git a/include/stdio.h b/include/stdio.h
> index 24f1652f19..364f4d22a1 100644
> --- a/include/stdio.h
> +++ b/include/stdio.h
> @@ -62,6 +62,7 @@ extern int __vsscanf (const char *__restrict __s,
>  extern int __sprintf_chk (char *, int, size_t, const char *, ...) __THROW;
>  extern int __snprintf_chk (char *, size_t, int, size_t, const char *, ...)
>       __THROW;
> +stdio_hidden_ldbl_proto (__, snprintf_chk)
>  extern int __vsprintf_chk (char *, int, size_t, const char *,
>  			   __gnuc_va_list) __THROW;
>  extern int __vsnprintf_chk (char *, size_t, int, size_t, const char *,