[v5,2/2] debug: Synchronize feature guards in fortified functions [BZ #28746]

  Some functions (e.g. stpcpy, pread64, etc.) had moved to POSIX in the
main headers as they got incorporated into the standard, but their
fortified variants remained under __USE_GNU.  As a result, these
functions did not get fortified when _GNU_SOURCE was not defined.

Add test wrappers that check all functions tested in tst-chk0 at all
levels with _GNU_SOURCE undefined and then use the failures to (1)
exclude checks for _GNU_SOURCE functions in these tests and (2) Fix
feature macro guards in the fortified function headers so that they're
the same as the ones in the main headers.

This fixes BZ #28746.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
---
 debug/Makefile                 | 10 +++++--
 debug/tst-fortify.c            | 49 ++++++++++++++++++++++++++++------
 posix/bits/unistd.h            |  2 +-
 string/bits/string_fortified.h |  8 +++---
 support/xsignal.h              |  2 ++
 wcsmbs/bits/wchar2.h           |  2 +-
 6 files changed, 58 insertions(+), 15 deletions(-)
  

On 12/01/2022 02:51, Siddhesh Poyarekar wrote:
> Some functions (e.g. stpcpy, pread64, etc.) had moved to POSIX in the
> main headers as they got incorporated into the standard, but their
> fortified variants remained under __USE_GNU.  As a result, these
> functions did not get fortified when _GNU_SOURCE was not defined.
> 
> Add test wrappers that check all functions tested in tst-chk0 at all
> levels with _GNU_SOURCE undefined and then use the failures to (1)
> exclude checks for _GNU_SOURCE functions in these tests and (2) Fix
> feature macro guards in the fortified function headers so that they're
> the same as the ones in the main headers.
> 
> This fixes BZ #28746.
> 
> Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

LGTM, thanks.

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

> ---
>  debug/Makefile                 | 10 +++++--
>  debug/tst-fortify.c            | 49 ++++++++++++++++++++++++++++------
>  posix/bits/unistd.h            |  2 +-
>  string/bits/string_fortified.h |  8 +++---
>  support/xsignal.h              |  2 ++
>  wcsmbs/bits/wchar2.h           |  2 +-
>  6 files changed, 58 insertions(+), 15 deletions(-)
> 
> diff --git a/debug/Makefile b/debug/Makefile
> index 880477632e..96029f32ee 100644
> --- a/debug/Makefile
> +++ b/debug/Makefile
> @@ -132,6 +132,12 @@ define cflags-lfs
>  CFLAGS-tst-fortify-$(1)-lfs-$(2).$(1) += -D_FILE_OFFSET_BITS=64
>  endef
>  
> +define cflags-nongnu
> +CFLAGS-tst-fortify-$(1)-nongnu-$(2).$(1) += -D_LARGEFILE64_SOURCE=1
> +endef
> +
> +src-chk-nongnu = \#undef _GNU_SOURCE
> +
>  # We know these tests have problems with format strings, this is what
>  # we are testing.  Disable that warning.  They are also testing
>  # deprecated functions (notably gets) so disable that warning as well.
> @@ -145,13 +151,13 @@ CFLAGS-tst-fortify-$(1)-$(2)-$(3).$(1) += -D_FORTIFY_SOURCE=$(3) -Wno-format \
>  $(eval $(call cflags-$(2),$(1),$(3)))
>  $(objpfx)tst-fortify-$(1)-$(2)-$(3).$(1): tst-fortify.c Makefile
>  	( echo "/* Autogenerated from Makefile.  */"; \
> -	  echo ""; \
> +	  echo "$(src-chk-$(2))"; \
>  	  echo "#include \"tst-fortify.c\"" ) > $$@.tmp
>  	mv $$@.tmp $$@
>  endef
>  
>  chk-extensions = c cc
> -chk-types = default lfs
> +chk-types = default lfs nongnu
>  chk-levels = 1 2 3
>  
>  $(foreach e,$(chk-extensions), \
> diff --git a/debug/tst-fortify.c b/debug/tst-fortify.c
> index 9288610fe6..d65a2fe6e1 100644
> --- a/debug/tst-fortify.c
> +++ b/debug/tst-fortify.c
> @@ -1,4 +1,5 @@
>  /* Copyright (C) 2004-2022 Free Software Foundation, Inc.
> +   Copyright The GNU Toolchain Authors.
>     This file is part of the GNU C Library.
>  
>     The GNU C Library is free software; you can redistribute it and/or
> @@ -36,6 +37,17 @@
>  #include <sys/socket.h>
>  #include <sys/un.h>
>  
> +#ifndef _GNU_SOURCE
> +# define MEMPCPY memcpy
> +# define WMEMPCPY wmemcpy
> +# define MEMPCPY_RET(x) 0
> +# define WMEMPCPY_RET(x) 0
> +#else
> +# define MEMPCPY mempcpy
> +# define WMEMPCPY wmempcpy
> +# define MEMPCPY_RET(x) __builtin_strlen (x)
> +# define WMEMPCPY_RET(x) wcslen (x)
> +#endif
>  
>  #define obstack_chunk_alloc malloc
>  #define obstack_chunk_free free
> @@ -162,7 +174,7 @@ do_test (void)
>    if (memcmp (buf, "aabcdefghi", 10))
>      FAIL ();
>  
> -  if (mempcpy (buf + 5, "abcde", 5) != buf + 10
> +  if (MEMPCPY (buf + 5, "abcde", 5) != buf + 5 + MEMPCPY_RET ("abcde")
>        || memcmp (buf, "aabcdabcde", 10))
>      FAIL ();
>  
> @@ -207,7 +219,7 @@ do_test (void)
>    if (memcmp (buf, "aabcdefghi", 10))
>      FAIL ();
>  
> -  if (mempcpy (buf + 5, "abcde", l0 + 5) != buf + 10
> +  if (MEMPCPY (buf + 5, "abcde", l0 + 5) != buf + 5 + MEMPCPY_RET ("abcde")
>        || memcmp (buf, "aabcdabcde", 10))
>      FAIL ();
>  
> @@ -266,7 +278,8 @@ do_test (void)
>    if (memcmp (a.buf1, "aabcdefghi", 10))
>      FAIL ();
>  
> -  if (mempcpy (a.buf1 + 5, "abcde", l0 + 5) != a.buf1 + 10
> +  if (MEMPCPY (a.buf1 + 5, "abcde", l0 + 5)
> +      != a.buf1 + 5 + MEMPCPY_RET ("abcde")
>        || memcmp (a.buf1, "aabcdabcde", 10))
>      FAIL ();
>  
> @@ -347,6 +360,7 @@ do_test (void)
>    bcopy (buf + 1, buf + 2, l0 + 9);
>    CHK_FAIL_END
>  
> +#ifdef _GNU_SOURCE
>    CHK_FAIL_START
>    p = (char *) mempcpy (buf + 6, "abcde", 5);
>    CHK_FAIL_END
> @@ -354,6 +368,7 @@ do_test (void)
>    CHK_FAIL_START
>    p = (char *) mempcpy (buf + 6, "abcde", l0 + 5);
>    CHK_FAIL_END
> +#endif
>  
>    CHK_FAIL_START
>    memset (buf + 9, 'j', 2);
> @@ -464,6 +479,7 @@ do_test (void)
>    bcopy (a.buf1 + 1, a.buf1 + 2, l0 + 9);
>    CHK_FAIL_END
>  
> +#ifdef _GNU_SOURCE
>    CHK_FAIL_START
>    p = (char *) mempcpy (a.buf1 + 6, "abcde", 5);
>    CHK_FAIL_END
> @@ -471,6 +487,7 @@ do_test (void)
>    CHK_FAIL_START
>    p = (char *) mempcpy (a.buf1 + 6, "abcde", l0 + 5);
>    CHK_FAIL_END
> +#endif
>  
>    CHK_FAIL_START
>    memset (a.buf1 + 9, 'j', 2);
> @@ -550,7 +567,7 @@ do_test (void)
>    if (wmemcmp (wbuf, L"aabcdefghi", 10))
>      FAIL ();
>  
> -  if (wmempcpy (wbuf + 5, L"abcde", 5) != wbuf + 10
> +  if (WMEMPCPY (wbuf + 5, L"abcde", 5) != wbuf + 5 + WMEMPCPY_RET (L"abcde")
>        || wmemcmp (wbuf, L"aabcdabcde", 10))
>      FAIL ();
>  
> @@ -583,7 +600,8 @@ do_test (void)
>    if (wmemcmp (wbuf, L"aabcdefghi", 10))
>      FAIL ();
>  
> -  if (wmempcpy (wbuf + 5, L"abcde", l0 + 5) != wbuf + 10
> +  if (WMEMPCPY (wbuf + 5, L"abcde", l0 + 5)
> +      != wbuf + 5 + WMEMPCPY_RET (L"abcde")
>        || wmemcmp (wbuf, L"aabcdabcde", 10))
>      FAIL ();
>  
> @@ -625,7 +643,8 @@ do_test (void)
>    if (wmemcmp (wa.buf1, L"aabcdefghi", 10))
>      FAIL ();
>  
> -  if (wmempcpy (wa.buf1 + 5, L"abcde", l0 + 5) != wa.buf1 + 10
> +  if (WMEMPCPY (wa.buf1 + 5, L"abcde", l0 + 5)
> +      != wa.buf1 + 5 + WMEMPCPY_RET (L"abcde")
>        || wmemcmp (wa.buf1, L"aabcdabcde", 10))
>      FAIL ();
>  
> @@ -694,6 +713,7 @@ do_test (void)
>    wmemmove (wbuf + 2, wbuf + 1, l0 + 9);
>    CHK_FAIL_END
>  
> +#ifdef _GNU_SOURCE
>    CHK_FAIL_START
>    wp = wmempcpy (wbuf + 6, L"abcde", 5);
>    CHK_FAIL_END
> @@ -701,6 +721,7 @@ do_test (void)
>    CHK_FAIL_START
>    wp = wmempcpy (wbuf + 6, L"abcde", l0 + 5);
>    CHK_FAIL_END
> +#endif
>  
>    CHK_FAIL_START
>    wmemset (wbuf + 9, L'j', 2);
> @@ -768,6 +789,7 @@ do_test (void)
>    wmemmove (wa.buf1 + 2, wa.buf1 + 1, l0 + 9);
>    CHK_FAIL_END
>  
> +#ifdef _GNU_SOURCE
>    CHK_FAIL_START
>    wp = wmempcpy (wa.buf1 + 6, L"abcde", 5);
>    CHK_FAIL_END
> @@ -775,6 +797,7 @@ do_test (void)
>    CHK_FAIL_START
>    wp = wmempcpy (wa.buf1 + 6, L"abcde", l0 + 5);
>    CHK_FAIL_END
> +#endif
>  
>    CHK_FAIL_START
>    wmemset (wa.buf1 + 9, L'j', 2);
> @@ -906,6 +929,7 @@ do_test (void)
>    if (fprintf (fp, buf2 + 4, str5) != 7)
>      FAIL ();
>  
> +#ifdef _GNU_SOURCE
>    char *my_ptr = NULL;
>    strcpy (buf2 + 2, "%n%s%n");
>    /* When the format string is writable and contains %n,
> @@ -935,6 +959,7 @@ do_test (void)
>    if (obstack_printf (&obs, "%s%n%s%n", str4, &n1, str5, &n1) != 14)
>      FAIL ();
>    obstack_free (&obs, NULL);
> +#endif
>  
>    if (freopen (temp_filename, "r", stdin) == NULL)
>      {
> @@ -982,6 +1007,7 @@ do_test (void)
>  
>    rewind (stdin);
>  
> +#ifdef _GNU_SOURCE
>    if (fgets_unlocked (buf, buf_size, stdin) != buf
>        || memcmp (buf, "abcdefgh\n", 10))
>      FAIL ();
> @@ -1008,6 +1034,7 @@ do_test (void)
>  #endif
>  
>    rewind (stdin);
> +#endif
>  
>    if (fread (buf, 1, buf_size, stdin) != buf_size
>        || memcmp (buf, "abcdefgh\nA", 10))
> @@ -1578,7 +1605,10 @@ do_test (void)
>        ret = 1;
>      }
>  
> -  int fd = posix_openpt (O_RDWR);
> +  int fd;
> +
> +#ifdef _GNU_SOURCE
> +  fd = posix_openpt (O_RDWR);
>    if (fd != -1)
>      {
>        char enough[1000];
> @@ -1594,6 +1624,7 @@ do_test (void)
>  #endif
>        close (fd);
>      }
> +#endif
>  
>  #if PATH_MAX > 0
>    confstr (_CS_GNU_LIBC_VERSION, largebuf, sizeof (largebuf));
> @@ -1711,8 +1742,9 @@ do_test (void)
>    poll (fds, l0 + 2, 0);
>    CHK_FAIL_END
>  #endif
> +#ifdef _GNU_SOURCE
>    ppoll (fds, 1, NULL, NULL);
> -#if __USE_FORTIFY_LEVEL >= 1
> +# if __USE_FORTIFY_LEVEL >= 1
>    CHK_FAIL_START
>    ppoll (fds, 2, NULL, NULL);
>    CHK_FAIL_END
> @@ -1720,6 +1752,7 @@ do_test (void)
>    CHK_FAIL_START
>    ppoll (fds, l0 + 2, NULL, NULL);
>    CHK_FAIL_END
> +# endif
>  #endif
>  
>    return ret;
> diff --git a/posix/bits/unistd.h b/posix/bits/unistd.h
> index 01df84b5f9..f53a7a06eb 100644
> --- a/posix/bits/unistd.h
> +++ b/posix/bits/unistd.h
> @@ -40,7 +40,7 @@ read (int __fd, void *__buf, size_t __nbytes)
>  			  __fd, __buf, __nbytes);
>  }
>  
> -#ifdef __USE_UNIX98
> +#if defined __USE_UNIX98 || defined __USE_XOPEN2K8
>  extern ssize_t __pread_chk (int __fd, void *__buf, size_t __nbytes,
>  			    __off_t __offset, size_t __bufsize)
>    __wur __attr_access ((__write_only__, 2, 3));
> diff --git a/string/bits/string_fortified.h b/string/bits/string_fortified.h
> index 51ad480401..f4a5dfc2e5 100644
> --- a/string/bits/string_fortified.h
> +++ b/string/bits/string_fortified.h
> @@ -79,7 +79,7 @@ __NTH (strcpy (char *__restrict __dest, const char *__restrict __src))
>    return __builtin___strcpy_chk (__dest, __src, __glibc_objsize (__dest));
>  }
>  
> -#ifdef __USE_GNU
> +#ifdef __USE_XOPEN2K8
>  __fortify_function char *
>  __NTH (stpcpy (char *__restrict __dest, const char *__restrict __src))
>  {
> @@ -96,14 +96,15 @@ __NTH (strncpy (char *__restrict __dest, const char *__restrict __src,
>  				  __glibc_objsize (__dest));
>  }
>  
> -#if __GNUC_PREREQ (4, 7) || __glibc_clang_prereq (2, 6)
> +#ifdef __USE_XOPEN2K8
> +# 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,
>  				  __glibc_objsize (__dest));
>  }
> -#else
> +# else
>  extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n,
>  			    size_t __destlen) __THROW
>    __fortified_attr_access ((__write_only__, 1, 3))
> @@ -119,6 +120,7 @@ __NTH (stpncpy (char *__dest, const char *__src, size_t __n))
>      return __stpncpy_chk (__dest, __src, __n, __bos (__dest));
>    return __stpncpy_alias (__dest, __src, __n);
>  }
> +# endif
>  #endif
>  
>  
> diff --git a/support/xsignal.h b/support/xsignal.h
> index 973f532495..d868bb336c 100644
> --- a/support/xsignal.h
> +++ b/support/xsignal.h
> @@ -28,7 +28,9 @@ __BEGIN_DECLS
>     terminate the process on error.  */
>  
>  void xraise (int sig);
> +#ifdef _GNU_SOURCE
>  sighandler_t xsignal (int sig, sighandler_t handler);
> +#endif
>  void xsigaction (int sig, const struct sigaction *newact,
>                   struct sigaction *oldact);
>  
> diff --git a/wcsmbs/bits/wchar2.h b/wcsmbs/bits/wchar2.h
> index 25d06d433f..0e017f458b 100644
> --- a/wcsmbs/bits/wchar2.h
> +++ b/wcsmbs/bits/wchar2.h
> @@ -457,7 +457,7 @@ __NTH (wcsrtombs (char *__restrict __dst, const wchar_t **__restrict __src,
>  }
>  
>  
> -#ifdef __USE_GNU
> +#ifdef	__USE_XOPEN2K8
>  extern size_t __mbsnrtowcs_chk (wchar_t *__restrict __dst,
>  				const char **__restrict __src, size_t __nmc,
>  				size_t __len, mbstate_t *__restrict __ps,