/* Unix SMB/CIFS implementation. Samba utility functions Copyright (C) Martin Pool 2003 Copyright (C) Andrew Bartlett 2003 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "includes.h" #ifdef DEVELOPER const char *global_clobber_region_function; unsigned int global_clobber_region_line; #endif /** * In developer builds, clobber a region of memory. * * If we think a string buffer is longer than it really is, this ought * to make the failure obvious, by segfaulting (if in the heap) or by * killing the return address (on the stack), or by trapping under a * memory debugger. * * This is meant to catch possible string overflows, even if the * actual string copied is not big enough to cause an overflow. * * In addition, under Valgrind the buffer is marked as uninitialized. **/ void clobber_region(const char *fn, unsigned int line, char *dest, size_t len) { #ifdef DEVELOPER global_clobber_region_function = fn; global_clobber_region_line = line; /* F1 is odd and 0xf1f1f1f1 shouldn't be a valid pointer */ memset(dest, 0xF1, len); #ifdef VALGRIND /* Even though we just wrote to this, from the application's * point of view it is not initialized. * * (This is not redundant with the clobbering above. The * marking might not actually take effect if we're not running * under valgrind.) */ #if defined(VALGRIND_MAKE_MEM_UNDEFINED) VALGRIND_MAKE_MEM_UNDEFINED(dest, len); #elif defined(VALGRIND_MAKE_WRITABLE) VALGRIND_MAKE_WRITABLE(dest, len); #endif #endif /* VALGRIND */ #endif /* DEVELOPER */ }