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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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37
debug/vdprintf_chk.c
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@ -24,41 +24,14 @@
This exception applies to code released by its copyright holders
in files containing the exception. */
#include <libioP.h>
#include <stdio_ext.h>
#include <libio/libioP.h>
int
__vdprintf_chk (int d, int flags, const char *format, va_list arg)
__vdprintf_chk (int d, int flag, const char *format, va_list ap)
{
struct _IO_FILE_plus tmpfil;
struct _IO_wide_data wd;
int done;
#ifdef _IO_MTSAFE_IO
tmpfil.file._lock = NULL;
#endif
_IO_no_init (&tmpfil.file, _IO_USER_LOCK, 0, &wd, &_IO_wfile_jumps);
_IO_JUMPS (&tmpfil) = &_IO_file_jumps;
_IO_new_file_init_internal (&tmpfil);
if (_IO_file_attach (&tmpfil.file, d) == NULL)
{
_IO_un_link (&tmpfil);
return EOF;
}
tmpfil.file._flags |= _IO_DELETE_DONT_CLOSE;
_IO_mask_flags (&tmpfil.file, _IO_NO_READS,
_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
/* 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)
tmpfil.file._flags2 |= _IO_FLAGS2_FORTIFY;
unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
done = __vfprintf_internal (&tmpfil.file, format, arg, 0);
_IO_FINISH (&tmpfil.file);
return done;
return __vdprintf_internal (d, format, ap, mode);
}
libc_hidden_def (__vdprintf_chk)