From 4e2f43f842ef5e253cc23383645adbaa03cedb86 Mon Sep 17 00:00:00 2001 From: Zack Weinberg Date: Wed, 7 Mar 2018 14:32:03 -0500 Subject: 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 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. --- debug/vswprintf_chk.c | 51 ++++++--------------------------------------------- 1 file changed, 6 insertions(+), 45 deletions(-) (limited to 'debug/vswprintf_chk.c') 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 . */ -#include -#include -#include "../libio/libioP.h" -#include "../libio/strfile.h" +#include /* 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) -- cgit v1.2.3