lib/clobber.c

説明を見る。
00001 /* 
00002    Unix SMB/CIFS implementation.
00003    Samba utility functions
00004    Copyright (C) Martin Pool     2003
00005    Copyright (C) Andrew Bartlett 2003
00006    
00007    This program is free software; you can redistribute it and/or modify
00008    it under the terms of the GNU General Public License as published by
00009    the Free Software Foundation; either version 2 of the License, or
00010    (at your option) any later version.
00011    
00012    This program is distributed in the hope that it will be useful,
00013    but WITHOUT ANY WARRANTY; without even the implied warranty of
00014    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015    GNU General Public License for more details.
00016    
00017    You should have received a copy of the GNU General Public License
00018    along with this program; if not, write to the Free Software
00019    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00020 */
00021 
00022 #include "includes.h"
00023 
00024 #ifdef DEVELOPER
00025 const char *global_clobber_region_function;
00026 unsigned int global_clobber_region_line;
00027 #endif
00028 
00029 /**
00030  * In developer builds, clobber a region of memory.
00031  *
00032  * If we think a string buffer is longer than it really is, this ought
00033  * to make the failure obvious, by segfaulting (if in the heap) or by
00034  * killing the return address (on the stack), or by trapping under a
00035  * memory debugger.
00036  *
00037  * This is meant to catch possible string overflows, even if the
00038  * actual string copied is not big enough to cause an overflow.
00039  *
00040  * In addition, under Valgrind the buffer is marked as uninitialized.
00041  **/
00042 void clobber_region(const char *fn, unsigned int line, char *dest, size_t len)
00043 {
00044 #ifdef DEVELOPER
00045         global_clobber_region_function = fn;
00046         global_clobber_region_line = line;
00047 
00048         /* F1 is odd and 0xf1f1f1f1 shouldn't be a valid pointer */
00049         memset(dest, 0xF1, len);
00050 #ifdef VALGRIND
00051         /* Even though we just wrote to this, from the application's
00052          * point of view it is not initialized.
00053          *
00054          * (This is not redundant with the clobbering above.  The
00055          * marking might not actually take effect if we're not running
00056          * under valgrind.) */
00057 #if defined(VALGRIND_MAKE_MEM_UNDEFINED)
00058         VALGRIND_MAKE_MEM_UNDEFINED(dest, len);
00059 #elif defined(VALGRIND_MAKE_WRITABLE)
00060         VALGRIND_MAKE_WRITABLE(dest, len);
00061 #endif
00062 #endif /* VALGRIND */
00063 #endif /* DEVELOPER */
00064 }

Sambaに対してSat Aug 29 21:22:58 2009に生成されました。  doxygen 1.4.7