diff options
Diffstat (limited to 'debug/vasprintf_chk.c')
-rw-r--r-- | debug/vasprintf_chk.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/debug/vasprintf_chk.c b/debug/vasprintf_chk.c new file mode 100644 index 0000000000..6105516d59 --- /dev/null +++ b/debug/vasprintf_chk.c @@ -0,0 +1,97 @@ +/* Copyright (C) 1995,1997,1999-2002,2004,2006,2008 + Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. + + As a special exception, if you link the code in this file with + files compiled with a GNU compiler to produce an executable, + that does not cause the resulting executable to be covered by + the GNU Lesser General Public License. This exception does not + however invalidate any other reasons why the executable file + might be covered by the GNU Lesser General Public License. + This exception applies to code released by its copyright holders + in files containing the exception. */ + +#include <malloc.h> +#include <string.h> +#include <stdio.h> +#include <stdio_ext.h> +#include "../libio/libioP.h" +#include "../libio/strfile.h" + +int +__vasprintf_chk (char **result_ptr, int flags, const char *format, + va_list args) +{ + /* Initial size of the buffer to be used. Will be doubled each time an + overflow occurs. */ + const _IO_size_t init_string_size = 100; + char *string; + _IO_strfile sf; + int ret; + _IO_size_t needed; + _IO_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 ((_IO_FILE *) &sf._sbf, _IO_USER_LOCK, -1, NULL, NULL); + _IO_JUMPS ((struct _IO_FILE_plus *) &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 = (_IO_alloc_type) malloc; + sf._s._free_buffer = (_IO_free_type) free; + + /* For flags > 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; + + ret = INTUSE(_IO_vfprintf) (&sf._sbf._f, format, args); + 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; +} +libc_hidden_def (__vasprintf_chk) |