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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
libio/libioP.h
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@ -677,9 +677,16 @@ extern int __obstack_vprintf_internal (struct obstack *ob, const char *fmt,
va_list ap, unsigned int mode_flags)
attribute_hidden;
extern int __vsprintf_internal (char *string, const char *format, va_list ap,
/* Note: __vsprintf_internal, unlike vsprintf, does take a maxlen argument,
because it's called by both vsprintf and vsprintf_chk. If maxlen is
not set to -1, overrunning the buffer will cause a prompt crash.
This is the behavior of ordinary (v)sprintf functions, thus they call
__vsprintf_internal with that argument set to -1. */
extern int __vsprintf_internal (char *string, size_t maxlen,
const char *format, va_list ap,
unsigned int mode_flags)
attribute_hidden;
extern int __vsnprintf_internal (char *string, size_t maxlen,
const char *format, va_list ap,
unsigned int mode_flags)
@ -818,26 +825,10 @@ _IO_acquire_lock_fct (FILE **p)
_IO_funlockfile (fp);
}
static inline void
__attribute__ ((__always_inline__))
_IO_acquire_lock_clear_flags2_fct (FILE **p)
{
FILE *fp = *p;
fp->_flags2 &= ~(_IO_FLAGS2_FORTIFY);
if ((fp->_flags & _IO_USER_LOCK) == 0)
_IO_funlockfile (fp);
}
#if !defined _IO_MTSAFE_IO && IS_IN (libc)
# define _IO_acquire_lock(_fp) \
do { \
FILE *_IO_acquire_lock_file = NULL
# define _IO_acquire_lock_clear_flags2(_fp) \
do { \
FILE *_IO_acquire_lock_file = (_fp)
do {
# define _IO_release_lock(_fp) \
if (_IO_acquire_lock_file != NULL) \
_IO_acquire_lock_file->_flags2 &= ~(_IO_FLAGS2_FORTIFY); \
} while (0)
#endif