Re: [PATCH v3 08/16] wchar: Avoid PLT entries with _FORTIFY_SOURCE

[Frederic Berat <fberat@redhat.com>]

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On Fri, Jun 30, 2023 at 5:17 PM Siddhesh Poyarekar <siddhesh@gotplt.org>
wrote:

>
>
> On 2023-06-28 04:42, Frédéric Bérat wrote:
> > The change is meant to avoid unwanted PLT entries for the wmemset and
> > wcrtomb routines when _FORTIFY_SOURCE is set.
> >
> > On top of that, ensure that *_chk routines have their hidden builtin
> > definitions available.
> > ---
>
> Looks mostly OK except for a question below.
>
> >   debug/wcrtomb_chk.c                               |  1 +
> >   debug/wmemset_chk.c                               |  1 +
> >   include/wchar.h                                   | 15 +++++++++++++++
> >   .../ldbl-128ibm-compat/ieee128-fwprintf_chk.c     |  1 +
> >   sysdeps/x86_64/multiarch/wmemset_chk.c            |  4 ++++
> >   wcsmbs/bits/wchar2-decl.h                         |  4 ++--
> >   6 files changed, 24 insertions(+), 2 deletions(-)
> >
> > diff --git a/debug/wcrtomb_chk.c b/debug/wcrtomb_chk.c
> > index 657be7471d..c156fe09c1 100644
> > --- a/debug/wcrtomb_chk.c
> > +++ b/debug/wcrtomb_chk.c
> > @@ -28,3 +28,4 @@ __wcrtomb_chk (char *s, wchar_t wchar, mbstate_t *ps,
> size_t buflen)
> >   {
> >     return __wcrtomb_internal (s, wchar, ps, buflen);
> >   }
> > +libc_hidden_def (__wcrtomb_chk)
> > diff --git a/debug/wmemset_chk.c b/debug/wmemset_chk.c
> > index e11a92815e..1e7fc4fdea 100644
> > --- a/debug/wmemset_chk.c
> > +++ b/debug/wmemset_chk.c
> > @@ -26,3 +26,4 @@ __wmemset_chk (wchar_t *s, wchar_t c, size_t n, size_t
> dstlen)
> >
> >     return wmemset (s, c, n);
> >   }
> > +libc_hidden_builtin_def (__wmemset_chk)
> > diff --git a/include/wchar.h b/include/wchar.h
> > index 7b763bc24f..484e6b3fef 100644
> > --- a/include/wchar.h
> > +++ b/include/wchar.h
> > @@ -166,6 +166,8 @@ libc_hidden_proto (putwc)
> >
> >   libc_hidden_proto (mbrtowc)
> >   libc_hidden_proto (wcrtomb)
> > +libc_hidden_proto (__wcrtomb_chk)
> > +
> >   extern int __wcscmp (const wchar_t *__s1, const wchar_t *__s2)
> >        __THROW __attribute_pure__;
> >   libc_hidden_proto (__wcscmp)
> > @@ -260,16 +262,25 @@ extern wchar_t *__wcschrnul (const wchar_t *__s,
> wchar_t __wc)
> >
> >   extern wchar_t *__wmemset_chk (wchar_t *__s, wchar_t __c, size_t __n,
> >                              size_t __ns) __THROW;
> > +libc_hidden_builtin_proto (__wmemset_chk)
> >
> >   extern int __vfwscanf (__FILE *__restrict __s,
> >                      const wchar_t *__restrict __format,
> >                      __gnuc_va_list __arg)
> >        attribute_hidden
> >        /* __attribute__ ((__format__ (__wscanf__, 2, 0)) */;
> > +
> > +extern int __swprintf_chk (wchar_t *__restrict __s, size_t __n,
> > +                        int __flag, size_t __s_len,
> > +                        const wchar_t *__restrict __format, ...)
> > +     __THROW /* __attribute__ ((__format__ (__wprintf__, 5, 6))) */;
> > +
> >   extern int __fwprintf (__FILE *__restrict __s,
> >                      const wchar_t *__restrict __format, ...)
> >        attribute_hidden
> >        /* __attribute__ ((__format__ (__wprintf__, 2, 3))) */;
> > +extern int __wprintf_chk (int __flag, const wchar_t *__restrict
> __format,
> > +                       ...);
> >   extern int __vfwprintf_chk (FILE *__restrict __s, int __flag,
> >                           const wchar_t *__restrict __format,
> >                           __gnuc_va_list __arg)
> > @@ -279,6 +290,10 @@ extern int __vswprintf_chk (wchar_t *__restrict
> __s, size_t __n,
> >                           const wchar_t *__restrict __format,
> >                           __gnuc_va_list __arg)
> >        /* __attribute__ ((__format__ (__wprintf__, 5, 0))) */;
> > +extern int __fwprintf_chk (__FILE *__restrict __stream, int __flag,
> > +                        const wchar_t *__restrict __format, ...);
> > +extern int __vwprintf_chk (int __flag, const wchar_t *__restrict
> __format,
> > +                        __gnuc_va_list __ap);
> >
> >   extern int __isoc99_fwscanf (__FILE *__restrict __stream,
> >                            const wchar_t *__restrict __format, ...);
> > diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c
> b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c
> > index 5b6cc3e768..10658ab125 100644
> > --- a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c
> > +++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c
> > @@ -17,6 +17,7 @@
> >      <https://www.gnu.org/licenses/>.  */
> >
> >   #include <stdarg.h>
> > +#include <wchar.h>
> >   #include <libio/libioP.h>
>
> Why do you need this?
>

Probably a leftover from my investigation. I'll double check.

>
> >   extern int
> > diff --git a/sysdeps/x86_64/multiarch/wmemset_chk.c
> b/sysdeps/x86_64/multiarch/wmemset_chk.c
> > index ac93a1f376..00edf44918 100644
> > --- a/sysdeps/x86_64/multiarch/wmemset_chk.c
> > +++ b/sysdeps/x86_64/multiarch/wmemset_chk.c
> > @@ -28,4 +28,8 @@
> >
> >   libc_ifunc_redirected (__redirect_wmemset_chk, __wmemset_chk,
> >                      IFUNC_SELECTOR ());
> > +# ifdef SHARED
> > +__hidden_ver1 (__wmemset_chk, __GI___wmemset_chk,
> __redirect_wmemset_chk)
> > +  __attribute__ ((visibility ("hidden"))) __attribute_copy__
> (__wmemset_chk);
> > +# endif
> >   #endif
> > diff --git a/wcsmbs/bits/wchar2-decl.h b/wcsmbs/bits/wchar2-decl.h
> > index f3a2fd3c99..08c8ebd0e8 100644
> > --- a/wcsmbs/bits/wchar2-decl.h
> > +++ b/wcsmbs/bits/wchar2-decl.h
> > @@ -71,7 +71,7 @@ extern wchar_t *__REDIRECT_NTH (__wmempcpy_chk_warn,
> >
> >   extern wchar_t *__wmemset_chk (wchar_t *__s, wchar_t __c, size_t __n,
> >                              size_t __ns) __THROW;
> > -extern wchar_t *__REDIRECT_NTH (__wmemset_alias, (wchar_t *__s, wchar_t
> __c,
> > +extern wchar_t *__REDIRECT_FORTIFY_NTH (__wmemset_alias, (wchar_t *__s,
> wchar_t __c,
> >                                                         size_t __n),
> wmemset);
> >   extern wchar_t *__REDIRECT_NTH (__wmemset_chk_warn,
> >                               (wchar_t *__s, wchar_t __c, size_t __n,
> > @@ -203,7 +203,7 @@ extern wchar_t *__REDIRECT
> (__fgetws_unlocked_chk_warn,
> >   extern size_t __wcrtomb_chk (char *__restrict __s, wchar_t __wchar,
> >                            mbstate_t *__restrict __p,
> >                            size_t __buflen) __THROW __wur;
> > -extern size_t __REDIRECT_NTH (__wcrtomb_alias,
> > +extern size_t __REDIRECT_FORTIFY_NTH (__wcrtomb_alias,
> >                                     (char *__restrict __s, wchar_t
> __wchar,
> >                                     mbstate_t *__restrict __ps),
> wcrtomb) __wur;
> >
>
>