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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/vswprintf_chk.c
parentAdd __vsyslog_internal, with same flags as __v*printf_internal. (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/vswprintf_chk.c')
-rw-r--r--debug/vswprintf_chk.c51
1 files changed, 6 insertions, 45 deletions
diff --git a/debug/vswprintf_chk.c b/debug/vswprintf_chk.c
index 4d616f8835..2c6fadd463 100644
--- a/debug/vswprintf_chk.c
+++ b/debug/vswprintf_chk.c
@@ -15,60 +15,21 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <stdarg.h>
-#include <wchar.h>
-#include "../libio/libioP.h"
-#include "../libio/strfile.h"
+#include <libio/libioP.h>
/* Write formatted output into S, according to the format
string FORMAT, writing no more than MAXLEN characters. */
-/* VARARGS5 */
int
-__vswprintf_chk (wchar_t *s, size_t maxlen, int flags, size_t slen,
- const wchar_t *format, va_list args)
+__vswprintf_chk (wchar_t *s, size_t maxlen, int flag, size_t slen,
+ const wchar_t *format, va_list ap)
{
- /* XXX Maybe for less strict version do not fail immediately.
- Though, maxlen is supposed to be the size of buffer pointed
- to by s, so a conforming program can't pass such maxlen
- to *snprintf. */
if (__glibc_unlikely (slen < maxlen))
__chk_fail ();
- _IO_wstrnfile sf;
- struct _IO_wide_data wd;
- int ret;
-#ifdef _IO_MTSAFE_IO
- sf.f._sbf._f._lock = NULL;
-#endif
-
- /* We need to handle the special case where MAXLEN is 0. Use the
- overflow buffer right from the start. */
- if (__glibc_unlikely (maxlen == 0))
- /* Since we have to write at least the terminating L'\0' a buffer
- length of zero always makes the function fail. */
- return -1;
-
- _IO_no_init (&sf.f._sbf._f, _IO_USER_LOCK, 0, &wd, &_IO_wstrn_jumps);
- _IO_fwide (&sf.f._sbf._f, 1);
- s[0] = L'\0';
-
- /* 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)
- sf.f._sbf._f._flags2 |= _IO_FLAGS2_FORTIFY;
-
- _IO_wstr_init_static (&sf.f._sbf._f, s, maxlen - 1, s);
- ret = __vfwprintf_internal ((FILE *) &sf.f._sbf, format, args, 0);
-
- if (sf.f._sbf._f._wide_data->_IO_buf_base == sf.overflow_buf)
- /* ISO C99 requires swprintf/vswprintf to return an error if the
- output does not fit int he provided buffer. */
- return -1;
-
- /* Terminate the string. */
- *sf.f._sbf._f._wide_data->_IO_write_ptr = '\0';
+ unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0;
- return ret;
+ return __vswprintf_internal (s, maxlen, format, ap, mode);
}
-libc_hidden_def (__vswprintf_chk)