[v7,3/4] string: Enable __FORTIFY_LEVEL=3

  This change enhances fortified string functions to use
__builtin_dynamic_object_size under _FORTIFY_SOURCE=3 whenever the
compiler supports it.
---
 include/string.h                |  5 +++--
 string/bits/string_fortified.h  | 29 ++++++++++++++++++-----------
 string/bits/strings_fortified.h |  6 ++++--
 3 files changed, 25 insertions(+), 15 deletions(-)
  

On 30/12/2020 03:43, Siddhesh Poyarekar wrote:
> This change enhances fortified string functions to use
> __builtin_dynamic_object_size under _FORTIFY_SOURCE=3 whenever the
> compiler supports it.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  include/string.h                |  5 +++--
>  string/bits/string_fortified.h  | 29 ++++++++++++++++++-----------
>  string/bits/strings_fortified.h |  6 ++++--
>  3 files changed, 25 insertions(+), 15 deletions(-)
> 
> diff --git a/include/string.h b/include/string.h
> index 7d344d77d4..81dab39891 100644
> --- a/include/string.h
> +++ b/include/string.h
> @@ -123,10 +123,11 @@ libc_hidden_proto (__strerror_l)
>  void __explicit_bzero_chk_internal (void *, size_t, size_t)
>    __THROW __nonnull ((1)) attribute_hidden;
>  # define explicit_bzero(buf, len) \
> -  __explicit_bzero_chk_internal (buf, len, __bos0 (buf))
> +  __explicit_bzero_chk_internal (buf, len, __glibc_objsize0 (buf))
>  #elif !IS_IN (nonlib)
>  void __explicit_bzero_chk (void *, size_t, size_t) __THROW __nonnull ((1));
> -# define explicit_bzero(buf, len) __explicit_bzero_chk (buf, len, __bos0 (buf))
> +# define explicit_bzero(buf, len) __explicit_bzero_chk (buf, len,	      \
> +							__glibc_objsize0 (buf))
>  #endif
>  
>  libc_hidden_builtin_proto (memchr)
> diff --git a/string/bits/string_fortified.h b/string/bits/string_fortified.h
> index 4c1aeb45f1..92d75f10fa 100644
> --- a/string/bits/string_fortified.h
> +++ b/string/bits/string_fortified.h
> @@ -26,13 +26,15 @@ __fortify_function void *
>  __NTH (memcpy (void *__restrict __dest, const void *__restrict __src,
>  	       size_t __len))
>  {
> -  return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest));
> +  return __builtin___memcpy_chk (__dest, __src, __len,
> +				 __glibc_objsize0 (__dest));
>  }
>  
>  __fortify_function void *
>  __NTH (memmove (void *__dest, const void *__src, size_t __len))
>  {
> -  return __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest));
> +  return __builtin___memmove_chk (__dest, __src, __len,
> +				  __glibc_objsize0 (__dest));
>  }
>  
>  #ifdef __USE_GNU
> @@ -40,7 +42,8 @@ __fortify_function void *
>  __NTH (mempcpy (void *__restrict __dest, const void *__restrict __src,
>  		size_t __len))
>  {
> -  return __builtin___mempcpy_chk (__dest, __src, __len, __bos0 (__dest));
> +  return __builtin___mempcpy_chk (__dest, __src, __len,
> +				  __glibc_objsize0 (__dest));
>  }
>  #endif
>  
> @@ -53,7 +56,8 @@ __NTH (mempcpy (void *__restrict __dest, const void *__restrict __src,
>  __fortify_function void *
>  __NTH (memset (void *__dest, int __ch, size_t __len))
>  {
> -  return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
> +  return __builtin___memset_chk (__dest, __ch, __len,
> +				 __glibc_objsize0 (__dest));
>  }
>  
>  #ifdef __USE_MISC
> @@ -65,21 +69,21 @@ void __explicit_bzero_chk (void *__dest, size_t __len, size_t __destlen)
>  __fortify_function void
>  __NTH (explicit_bzero (void *__dest, size_t __len))
>  {
> -  __explicit_bzero_chk (__dest, __len, __bos0 (__dest));
> +  __explicit_bzero_chk (__dest, __len, __glibc_objsize0 (__dest));
>  }
>  #endif
>  
>  __fortify_function char *
>  __NTH (strcpy (char *__restrict __dest, const char *__restrict __src))
>  {
> -  return __builtin___strcpy_chk (__dest, __src, __bos (__dest));
> +  return __builtin___strcpy_chk (__dest, __src, __glibc_objsize (__dest));
>  }
>  
>  #ifdef __USE_GNU
>  __fortify_function char *
>  __NTH (stpcpy (char *__restrict __dest, const char *__restrict __src))
>  {
> -  return __builtin___stpcpy_chk (__dest, __src, __bos (__dest));
> +  return __builtin___stpcpy_chk (__dest, __src, __glibc_objsize (__dest));
>  }
>  #endif
>  
> @@ -88,14 +92,16 @@ __fortify_function char *
>  __NTH (strncpy (char *__restrict __dest, const char *__restrict __src,
>  		size_t __len))
>  {
> -  return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
> +  return __builtin___strncpy_chk (__dest, __src, __len,
> +				  __glibc_objsize (__dest));
>  }
>  
>  #if __GNUC_PREREQ (4, 7) || __glibc_clang_prereq (2, 6)
>  __fortify_function char *
>  __NTH (stpncpy (char *__dest, const char *__src, size_t __n))
>  {
> -  return __builtin___stpncpy_chk (__dest, __src, __n, __bos (__dest));
> +  return __builtin___stpncpy_chk (__dest, __src, __n,
> +				  __glibc_objsize (__dest));
>  }
>  #else
>  extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n,
> @@ -118,7 +124,7 @@ __NTH (stpncpy (char *__dest, const char *__src, size_t __n))
>  __fortify_function char *
>  __NTH (strcat (char *__restrict __dest, const char *__restrict __src))
>  {
> -  return __builtin___strcat_chk (__dest, __src, __bos (__dest));
> +  return __builtin___strcat_chk (__dest, __src, __glibc_objsize (__dest));
>  }
>  
>  
> @@ -126,7 +132,8 @@ __fortify_function char *
>  __NTH (strncat (char *__restrict __dest, const char *__restrict __src,
>  		size_t __len))
>  {
> -  return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
> +  return __builtin___strncat_chk (__dest, __src, __len,
> +				  __glibc_objsize (__dest));
>  }
>  
>  #endif /* bits/string_fortified.h */
> diff --git a/string/bits/strings_fortified.h b/string/bits/strings_fortified.h
> index d4091f4f69..7752faf4e3 100644
> --- a/string/bits/strings_fortified.h
> +++ b/string/bits/strings_fortified.h
> @@ -22,13 +22,15 @@
>  __fortify_function void
>  __NTH (bcopy (const void *__src, void *__dest, size_t __len))
>  {
> -  (void) __builtin___memmove_chk (__dest, __src, __len, __bos0 (__dest));
> +  (void) __builtin___memmove_chk (__dest, __src, __len,
> +				  __glibc_objsize0 (__dest));
>  }
>  
>  __fortify_function void
>  __NTH (bzero (void *__dest, size_t __len))
>  {
> -  (void) __builtin___memset_chk (__dest, '\0', __len, __bos0 (__dest));
> +  (void) __builtin___memset_chk (__dest, '\0', __len,
> +				 __glibc_objsize0 (__dest));
>  }
>  
>  #endif
>