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Use PRINTF_FORTIFY instead of _IO_FLAGS2_FORTIFY (bug 11319)

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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 7ca890b88e
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.
This commit is contained in:
Zack Weinberg
2018-03-07 14:32:03 -05:00
committed by Gabriel F. T. Gomes
parent 124fc732c1
commit 4e2f43f842
35 changed files with 413 additions and 551 deletions
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27
debug/swprintf_chk.c
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@@ -16,20 +16,27 @@
<http://www.gnu.org/licenses/>. */
#include <stdarg.h>
#include <wchar.h>
#include <libio/libioP.h>
/* Write formatted output into S, according to the format string FORMAT. */
/* VARARGS5 */
/* Write formatted output into S, according to the format string FORMAT,
writing no more than MAXLEN characters. */
int
__swprintf_chk (wchar_t *s, size_t n, int flag, size_t s_len,
__swprintf_chk (wchar_t *s, size_t maxlen, int flag, size_t slen,
const wchar_t *format, ...)
{
va_list arg;
int done;
if (__glibc_unlikely (slen < maxlen))
__chk_fail ();
va_start (arg, format);
done = __vswprintf_chk (s, n, flag, s_len, format, arg);
va_end (arg);
/* 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 ret;
return done;
va_start (ap, format);
ret = __vswprintf_internal (s, maxlen, format, ap, mode);
va_end (ap);
return ret;
}