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/vasprintf_chk.c | 68 ++++----------------------------------------------- 1 file changed, 5 insertions(+), 63 deletions(-) (limited to 'debug/vasprintf_chk.c') diff --git a/debug/vasprintf_chk.c b/debug/vasprintf_chk.c index dbfebff83f..f5975ea02a 100644 --- a/debug/vasprintf_chk.c +++ b/debug/vasprintf_chk.c @@ -24,72 +24,14 @@ This exception applies to code released by its copyright holders in files containing the exception. */ -#include -#include -#include -#include -#include "../libio/libioP.h" -#include "../libio/strfile.h" +#include int -__vasprintf_chk (char **result_ptr, int flags, const char *format, - va_list args) +__vasprintf_chk (char **result_ptr, int flag, const char *format, va_list ap) { - /* Initial size of the buffer to be used. Will be doubled each time an - overflow occurs. */ - const size_t init_string_size = 100; - char *string; - _IO_strfile sf; - int ret; - size_t needed; - size_t allocated; - /* No need to clear the memory here (unlike for open_memstream) since - we know we will never seek on the stream. */ - string = (char *) malloc (init_string_size); - if (string == NULL) - return -1; -#ifdef _IO_MTSAFE_IO - sf._sbf._f._lock = NULL; -#endif - _IO_no_init (&sf._sbf._f, _IO_USER_LOCK, -1, NULL, NULL); - _IO_JUMPS (&sf._sbf) = &_IO_str_jumps; - _IO_str_init_static_internal (&sf, string, init_string_size, string); - sf._sbf._f._flags &= ~_IO_USER_BUF; - sf._s._allocate_buffer_unused = (_IO_alloc_type) malloc; - sf._s._free_buffer_unused = (_IO_free_type) free; - - /* 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._sbf._f._flags2 |= _IO_FLAGS2_FORTIFY; + unsigned int mode = (flag > 0) ? PRINTF_FORTIFY : 0; - ret = __vfprintf_internal (&sf._sbf._f, format, args, 0); - if (ret < 0) - { - free (sf._sbf._f._IO_buf_base); - return ret; - } - /* Only use realloc if the size we need is of the same (binary) - order of magnitude then the memory we allocated. */ - needed = sf._sbf._f._IO_write_ptr - sf._sbf._f._IO_write_base + 1; - allocated = sf._sbf._f._IO_write_end - sf._sbf._f._IO_write_base; - if ((allocated >> 1) <= needed) - *result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed); - else - { - *result_ptr = (char *) malloc (needed); - if (*result_ptr != NULL) - { - memcpy (*result_ptr, sf._sbf._f._IO_buf_base, needed - 1); - free (sf._sbf._f._IO_buf_base); - } - else - /* We have no choice, use the buffer we already have. */ - *result_ptr = (char *) realloc (sf._sbf._f._IO_buf_base, needed); - } - if (*result_ptr == NULL) - *result_ptr = sf._sbf._f._IO_buf_base; - (*result_ptr)[needed - 1] = '\0'; - return ret; + return __vasprintf_internal (result_ptr, format, ap, mode); } -libc_hidden_def (__vasprintf_chk) -- cgit 1.4.1