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authorZack Weinberg <zackw@panix.com>2018-03-07 14:32:03 -0500
committerGabriel F. T. Gomes <gabriel@inconstante.eti.br>2018-12-05 18:15:43 -0200
commit4e2f43f842ef5e253cc23383645adbaa03cedb86 (patch)
treeca359423ba6ed4bb4d5ec247905a6ee13d456864 /debug/vfprintf_chk.c
parent124fc732c15ef37b7ee9db25b1e9f9b20c799623 (diff)
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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.
Diffstat (limited to 'debug/vfprintf_chk.c')
-rw-r--r--debug/vfprintf_chk.c21
1 files changed, 5 insertions, 16 deletions
diff --git a/debug/vfprintf_chk.c b/debug/vfprintf_chk.c
index 5babbf611e..44426e14fd 100644
--- a/debug/vfprintf_chk.c
+++ b/debug/vfprintf_chk.c
@@ -15,28 +15,17 @@
License along with the GNU C Library; if not, see
<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
___vfprintf_chk (FILE *fp, int flag, const char *format, va_list ap)
{
- int done;
+ /* 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;
- _IO_acquire_lock_clear_flags2 (fp);
- if (flag > 0)
- fp->_flags2 |= _IO_FLAGS2_FORTIFY;
-
- done = vfprintf (fp, format, ap);
-
- if (flag > 0)
- fp->_flags2 &= ~_IO_FLAGS2_FORTIFY;
- _IO_release_lock (fp);
-
- return done;
+ return __vfprintf_internal (fp, format, ap, mode);
}
-ldbl_hidden_def (___vfprintf_chk, __vfprintf_chk)
ldbl_strong_alias (___vfprintf_chk, __vfprintf_chk)