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/obprintf_chk.c | 96 ++++++---------------------------------------------- 1 file changed, 10 insertions(+), 86 deletions(-) (limited to 'debug/obprintf_chk.c') diff --git a/debug/obprintf_chk.c b/debug/obprintf_chk.c index 41dd481c34..c1a8f9e9a9 100644 --- a/debug/obprintf_chk.c +++ b/debug/obprintf_chk.c @@ -17,99 +17,23 @@ License along with the GNU C Library; if not, see . */ - -#include -#include -#include "../libio/strfile.h" -#include -#include -#include -#include +#include #include -#include - - -struct _IO_obstack_file -{ - struct _IO_FILE_plus file; - struct obstack *obstack; -}; - -extern const struct _IO_jump_t _IO_obstack_jumps libio_vtable attribute_hidden; - -int -__obstack_vprintf_chk (struct obstack *obstack, int flags, const char *format, - va_list args) -{ - struct obstack_FILE - { - struct _IO_obstack_file ofile; - } new_f; - int result; - int size; - int room; - -#ifdef _IO_MTSAFE_IO - new_f.ofile.file.file._lock = NULL; -#endif - - _IO_no_init (&new_f.ofile.file.file, _IO_USER_LOCK, -1, NULL, NULL); - _IO_JUMPS (&new_f.ofile.file) = &_IO_obstack_jumps; - room = obstack_room (obstack); - size = obstack_object_size (obstack) + room; - if (size == 0) - { - /* We have to handle the allocation a bit different since the - `_IO_str_init_static' function would handle a size of zero - different from what we expect. */ - - /* Get more memory. */ - obstack_make_room (obstack, 64); - - /* Recompute how much room we have. */ - room = obstack_room (obstack); - size = room; - - assert (size != 0); - } - - _IO_str_init_static_internal ((struct _IO_strfile_ *) &new_f.ofile, - obstack_base (obstack), - size, obstack_next_free (obstack)); - /* Now allocate the rest of the current chunk. */ - assert (size == (new_f.ofile.file.file._IO_write_end - - new_f.ofile.file.file._IO_write_base)); - assert (new_f.ofile.file.file._IO_write_ptr - == (new_f.ofile.file.file._IO_write_base - + obstack_object_size (obstack))); - obstack_blank_fast (obstack, room); - - new_f.ofile.obstack = obstack; - - /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n - can only come from read-only format strings. */ - if (flags > 0) - new_f.ofile.file.file._flags2 |= _IO_FLAGS2_FORTIFY; - - result = __vfprintf_internal (&new_f.ofile.file.file, format, args, 0); - - /* Shrink the buffer to the space we really currently need. */ - obstack_blank_fast (obstack, (new_f.ofile.file.file._IO_write_ptr - - new_f.ofile.file.file._IO_write_end)); - - return result; -} -libc_hidden_def (__obstack_vprintf_chk) int -__obstack_printf_chk (struct obstack *obstack, int flags, const char *format, +__obstack_printf_chk (struct obstack *obstack, int flag, const char *format, ...) { - int result; + /* 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; va_list ap; + int ret; + va_start (ap, format); - result = __obstack_vprintf_chk (obstack, flags, format, ap); + ret = __obstack_vprintf_internal (obstack, format, ap, mode); va_end (ap); - return result; + + return ret; } -- cgit v1.2.3