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, 7 insertions, 13 deletions

diff --git a/debug/fprintf_chk.c b/debug/fprintf_chk.c
index cff4438..14afc07 100644
--- a/debug/fprintf_chk.c
+++ b/debug/fprintf_chk.c
@@ -16,29 +16,23 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stdarg.h>
-#include <stdio.h>
-#include "../libio/libioP.h"
+#include <libio/libioP.h>
 
 
 /* Write formatted output to FP from the format string FORMAT.  */
 int
 ___fprintf_chk (FILE *fp, int flag, const char *format, ...)
 {
+  /* For flag > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n
+     can only come from read-only format strings.  */
+  unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
   va_list ap;
-  int done;
-
-  _IO_acquire_lock_clear_flags2 (fp);
-  if (flag > 0)
-    fp->_flags2 |= _IO_FLAGS2_FORTIFY;
+  int ret;
 
   va_start (ap, format);
-  done = vfprintf (fp, format, ap);
+  ret = __vfprintf_internal (fp, format, ap, mode);
   va_end (ap);
 
-  if (flag > 0)
-    fp->_flags2 &= ~_IO_FLAGS2_FORTIFY;
-  _IO_release_lock (fp);
-
-  return done;
+  return ret;
 }
 ldbl_strong_alias (___fprintf_chk, __fprintf_chk)