Use PRINTF_FORTIFY instead of _IO_FLAGS2_FORTIFY (bug 11319)

The _chk variants of all of the printf functions become much simpler.
This is the last thing that we needed _IO_acquire_lock_clear_flags2
for, so it can go as well.  I took the opportunity to make the headers
included and the names of all local variables consistent across all the
affected files.

Since we ultimately want to get rid of __no_long_double as well, it
must be possible to get all of the nontrivial effects of the _chk
functions by calling the _internal functions with appropriate flags.
For most of the __(v)xprintf_chk functions, this is covered by
PRINTF_FORTIFY plus some up-front argument checks that can be
duplicated.  However, __(v)sprintf_chk installs a custom jump table so
that it can crash instead of overflowing the output buffer.  This
functionality is moved to __vsprintf_internal, which now has a
'maxlen' argument like __vsnprintf_internal; to get the unsafe
behavior of ordinary (v)sprintf, pass -1 for that argument.

obstack_printf_chk and obstack_vprintf_chk are no longer in the same
file.

As a side-effect of the unification of both fortified and non-fortified
vdprintf initialization, this patch fixes bug 11319 for __dprintf_chk
and __vdprintf_chk, which was previously fixed only for dprintf and
vdprintf by the commit

commit 7ca890b88e6ab7624afb1742a9fffb37ad5b3fc3
Author: Ulrich Drepper <drepper@redhat.com>
Date:   Wed Feb 24 16:07:57 2010 -0800

    Fix reporting of I/O errors in *dprintf functions.

This patch adds a test case to avoid regressions.

Tested for powerpc and powerpc64le.

1 files changed, 6 insertions, 40 deletions

diff --git a/debug/vsnprintf_chk.c b/debug/vsnprintf_chk.c
index 95d286f416..666a83b701 100644
--- a/debug/vsnprintf_chk.c
+++ b/debug/vsnprintf_chk.c
@@ -15,56 +15,22 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <stdarg.h>
-#include <stdio.h>
-#include "../libio/libioP.h"
-#include "../libio/strfile.h"
+#include <libio/libioP.h>
 
-extern const struct _IO_jump_t _IO_strn_jumps libio_vtable attribute_hidden;
 
 /* Write formatted output into S, according to the format
    string FORMAT, writing no more than MAXLEN characters.  */
-/* VARARGS5 */
 int
-___vsnprintf_chk (char *s, size_t maxlen, int flags, size_t slen,
-		  const char *format, va_list args)
+___vsnprintf_chk (char *s, size_t maxlen, int flag, size_t slen,
+		  const char *format, va_list ap)
 {
-  /* XXX Maybe for less strict version do not fail immediately.
-     Though, maxlen is supposed to be the size of buffer pointed
-     to by s, so a conforming program can't pass such maxlen
-     to *snprintf.  */
   if (__glibc_unlikely (slen < maxlen))
     __chk_fail ();
 
-  _IO_strnfile sf;
-  int ret;
-#ifdef _IO_MTSAFE_IO
-  sf.f._sbf._f._lock = NULL;
-#endif
-
-  /* We need to handle the special case where MAXLEN is 0.  Use the
-     overflow buffer right from the start.  */
-  if (maxlen == 0)
-    {
-      s = sf.overflow_buf;
-      maxlen = sizeof (sf.overflow_buf);
-    }
-
-  _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, -1, NULL, NULL);
-  _IO_JUMPS (&sf.f._sbf) = &_IO_strn_jumps;
-  s[0] = '\0';
-
-  /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
+  /* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
      can only come from read-only format strings.  */
-  if (flags > 0)
-    sf.f._sbf._f._flags2 |= _IO_FLAGS2_FORTIFY;
-
-  _IO_str_init_static_internal (&sf.f, s, maxlen - 1, s);
-  ret = __vfprintf_internal (&sf.f._sbf._f, format, args, 0);
+  unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
 
-  if (sf.f._sbf._f._IO_buf_base != sf.overflow_buf)
-    *sf.f._sbf._f._IO_write_ptr = '\0';
-  return ret;
+  return __vsnprintf_internal (s, maxlen, format, ap, mode);
 }
-ldbl_hidden_def (___vsnprintf_chk, __vsnprintf_chk)
 ldbl_strong_alias (___vsnprintf_chk, __vsnprintf_chk)