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, 49 insertions, 0 deletions

diff --git a/stdio-common/tst-bz11319.c b/stdio-common/tst-bz11319.c
new file mode 100644
index 0000000000..f986c39a66
--- /dev/null
+++ b/stdio-common/tst-bz11319.c
@@ -0,0 +1,49 @@
+/* Regression test for bug 11319.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE 1
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <support/check.h>
+#include <support/temp_file.h>
+#include <support/xunistd.h>
+
+static int
+do_test (void)
+{
+  char *tempfile;
+  int fd;
+
+  /* Create a temporary file and open it in read-only mode.  */
+  TEST_VERIFY_EXIT (create_temp_file ("tst-bz11319", &tempfile));
+  fd = xopen (tempfile, O_RDONLY, 0660);
+
+  /* Try and write to the temporary file to intentionally fail, then
+     check that dprintf (or __dprintf_chk) return EOF.  */
+  TEST_COMPARE (dprintf (fd, "%d", 0), EOF);
+
+  xclose (fd);
+  free (tempfile);
+
+  return 0;
+}
+
+#include <support/test-driver.c>