diff options
Diffstat (limited to 'mmalloc/mmcheck.c')
| -rw-r--r-- | mmalloc/mmcheck.c | 196 |
1 files changed, 0 insertions, 196 deletions
diff --git a/mmalloc/mmcheck.c b/mmalloc/mmcheck.c deleted file mode 100644 index 2a4b09e..0000000 --- a/mmalloc/mmcheck.c +++ /dev/null @@ -1,196 +0,0 @@ -/* Standard debugging hooks for `mmalloc'. - Copyright 1990, 1991, 1992 Free Software Foundation - - Written May 1989 by Mike Haertel. - Heavily modified Mar 1992 by Fred Fish (fnf@cygnus.com) - -The GNU C Library is free software; you can redistribute it and/or -modify it under the terms of the GNU Library General Public License as -published by the Free Software Foundation; either version 2 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 -Library General Public License for more details. - -You should have received a copy of the GNU Library General Public -License along with the GNU C Library; see the file COPYING.LIB. If -not, write to the Free Software Foundation, Inc., 675 Mass Ave, -Cambridge, MA 02139, USA. - - The author may be reached (Email) at the address mike@ai.mit.edu, - or (US mail) as Mike Haertel c/o Free Software Foundation. */ - -#include "mmalloc.h" - -/* Default function to call when something awful happens. The application - can specify an alternate function to be called instead (and probably will - want to). */ - -extern void abort PARAMS ((void)); - -/* Arbitrary magical numbers. */ - -#define MAGICWORD 0xfedabeeb /* Magic word for active chunk */ -#define MAGICWORDFREE 0xdeadbeef /* Magic word for inactive chunk */ -#define MAGICBYTE ((char) 0xd7) - -/* Each memory allocation is bounded by a header structure and a trailer - byte. I.E. - - <size><magicword><user's allocation><magicbyte> - - The pointer returned to the user points to the first byte in the - user's allocation area. The magic word can be tested to detect - buffer underruns and the magic byte can be tested to detect overruns. */ - -struct hdr - { - size_t size; /* Exact size requested by user. */ - unsigned long int magic; /* Magic number to check header integrity. */ - }; - -/* Check the magicword and magicbyte, and if either is corrupted then - call the emergency abort function specified for the heap in use. */ - -static void -checkhdr (mdp, hdr) - struct mdesc *mdp; - CONST struct hdr *hdr; -{ - if (hdr -> magic != MAGICWORD || - ((char *) &hdr[1])[hdr -> size] != MAGICBYTE) - { - (*mdp -> abortfunc)(); - } -} - -static void -mfree_check (md, ptr) - PTR md; - PTR ptr; -{ - struct hdr *hdr = ((struct hdr *) ptr) - 1; - struct mdesc *mdp; - - mdp = MD_TO_MDP (md); - checkhdr (mdp, hdr); - hdr -> magic = MAGICWORDFREE; - mdp -> mfree_hook = NULL; - mfree (md, hdr); - mdp -> mfree_hook = mfree_check; -} - -static PTR -mmalloc_check (md, size) - PTR md; - size_t size; -{ - struct hdr *hdr; - struct mdesc *mdp; - size_t nbytes; - - mdp = MD_TO_MDP (md); - mdp -> mmalloc_hook = NULL; - nbytes = sizeof (struct hdr) + size + 1; - hdr = (struct hdr *) mmalloc (md, nbytes); - mdp -> mmalloc_hook = mmalloc_check; - if (hdr != NULL) - { - hdr -> size = size; - hdr -> magic = MAGICWORD; - hdr++; - *((char *) hdr + size) = MAGICBYTE; - } - return ((PTR) hdr); -} - -static PTR -mrealloc_check (md, ptr, size) - PTR md; - PTR ptr; - size_t size; -{ - struct hdr *hdr = ((struct hdr *) ptr) - 1; - struct mdesc *mdp; - size_t nbytes; - - mdp = MD_TO_MDP (md); - checkhdr (mdp, hdr); - mdp -> mfree_hook = NULL; - mdp -> mmalloc_hook = NULL; - mdp -> mrealloc_hook = NULL; - nbytes = sizeof (struct hdr) + size + 1; - hdr = (struct hdr *) mrealloc (md, (PTR) hdr, nbytes); - mdp -> mfree_hook = mfree_check; - mdp -> mmalloc_hook = mmalloc_check; - mdp -> mrealloc_hook = mrealloc_check; - if (hdr != NULL) - { - hdr -> size = size; - hdr++; - *((char *) hdr + size) = MAGICBYTE; - } - return ((PTR) hdr); -} - -/* Turn on default checking for mmalloc/mrealloc/mfree, for the heap specified - by MD. If FUNC is non-NULL, it is a pointer to the function to call - to abort whenever memory corruption is detected. By default, this is the - standard library function abort(). - - Note that we disallow installation of initial checking hooks if mmalloc - has been called at any time for this particular heap, since if any region - that is allocated prior to installation of the hooks is subsequently - reallocated or freed after installation of the hooks, it is guaranteed - to trigger a memory corruption error. We do this by checking the state - of the MMALLOC_INITIALIZED flag. - - However, we can call this function at any time after the initial call, - to update the function pointers to the checking routines and to the - user defined corruption handler routine, as long as these function pointers - have been previously extablished by the initial call. Note that we - do this automatically when remapping an previously used heap, to ensure - that the hooks get updated to the correct values, although the corruption - handler pointer gets set back to the default. The application can then - call mmcheck to use a different corruption handler if desired. - - Returns non-zero if checking is successfully enabled, zero otherwise. */ - -int -mmcheck (md, func) - PTR md; - void (*func) PARAMS ((void)); -{ - struct mdesc *mdp; - int rtnval; - - mdp = MD_TO_MDP (md); - - /* We can safely set or update the abort function at any time, regardless - of whether or not we successfully do anything else. */ - - mdp -> abortfunc = (func != NULL ? func : abort); - - /* If we haven't yet called mmalloc the first time for this heap, or if we - have hooks that were previously installed, then allow the hooks to be - initialized or updated. */ - - if (1 /* FIXME: Always allow installation for now. */ || - !(mdp -> flags & MMALLOC_INITIALIZED) || - (mdp -> mfree_hook != NULL)) - { - mdp -> mfree_hook = mfree_check; - mdp -> mmalloc_hook = mmalloc_check; - mdp -> mrealloc_hook = mrealloc_check; - mdp -> flags |= MMALLOC_MMCHECK_USED; - rtnval = 1; - } - else - { - rtnval = 0; - } - - return (rtnval); -} |