1 files changed, 330 insertions, 0 deletions
diff --git a/private/crt32/heap/heapchk.c b/private/crt32/heap/heapchk.c
new file mode 100644
index 000000000..872b124d5
--- /dev/null
+++ b/private/crt32/heap/heapchk.c
@@ -0,0 +1,330 @@
+/***
+*heapchk.c - perform a consistency check on the heap
+*
+*	Copyright (c) 1989-1991, Microsoft Corporation. All rights reserved.
+*
+*Purpose:
+*	Defines the _heapchk() and _heapset() functions
+*
+*Revision History:
+*	06-30-89   JCR	Module created.
+*	07-28-89   GJF	Added check for free block preceding the rover
+*	11-13-89   GJF	Added MTHREAD support, also fixed copyright
+*	12-13-89   GJF	Added check for descriptor order, did some tuning,
+*			changed header file name to heap.h
+*	12-15-89   GJF	Purged DEBUG286 stuff. Also added explicit _cdecl to
+*			function definitions.
+*	12-19-89   GJF	Got rid of checks involving plastdesc (revised check
+*			of proverdesc and DEBUG errors accordingly)
+*	03-09-90   GJF	Replaced _cdecl with _CALLTYPE1, added #include
+*			<cruntime.h> and removed #include <register.h>.
+*	03-29-90   GJF	Made _heap_checkset() _CALLTYPE4.
+*	09-27-90   GJF	New-style function declarators.
+*	03-05-91   GJF	Changed strategy for rover - old version available
+*			by #define-ing _OLDROVER_.
+*
+*******************************************************************************/
+
+#include <cruntime.h>
+#include <heap.h>
+#include <malloc.h>
+#include <os2dll.h>
+#include <stddef.h>
+#include <string.h>
+#ifdef DEBUG
+#include <stdio.h>
+#endif
+
+static int _CALLTYPE4 _heap_checkset(unsigned int _fill);
+
+/* Debug error values */
+#define _EMPTYHEAP   0
+#define _BADROVER    1
+#define _BADRANGE    2
+#define _BADSENTINEL 3
+#define _BADEMPTY    4
+#define _EMPTYLOOP   5
+#define _BADFREE     6
+#define _BADORDER    7
+
+#ifdef DEBUG
+
+static char *errmsgs[] = {
+	"_heap_desc.pfirstdesc == NULL",
+	"_heap_desc.proverdesc not found in desc list",
+	"address is outside the heap",
+	"sentinel descriptor corrupted",
+	"empty desc pblock != NULL (debug version)",
+	"header ptr found twice in emptylist",
+	"free block precedes rover",
+	"adjacent descriptors in reverse order from heap blocks"
+	};
+
+#define _PRINTERR(msg) \
+	printf("\n*** HEAP ERROR: %s ***\n", errmsgs[(msg)]);  \
+	fflush(stdout);
+
+#else	/* !DEBUG */
+
+#define _PRINTERR(msg)
+
+#endif	/* DEBUG */
+
+
+/***
+*int _heapchk()      - Validate the heap
+*int _heapset(_fill) - Validate the heap and fill in free entries
+*
+*Purpose:
+*	Performs a consistency check on the heap.
+*
+*Entry:
+*	For heapchk()
+*		No arguments
+*	For heapset()
+*		int _fill - value to be used as filler in free entries
+*
+*Exit:
+*	Returns one of the following values:
+*
+*		_HEAPOK 	 - completed okay
+*		_HEAPEMPTY	 - heap not initialized
+*		_HEAPBADBEGIN	 - can't find initial header info
+*		_HEAPBADNODE	 - malformed node somewhere
+*
+*	Debug version prints out a diagnostic message if an error is found
+*	(see errmsg[] above).
+*
+*	NOTE:  Add code to support memory regions.
+*
+*Uses:
+*
+*Exceptions:
+*
+*******************************************************************************/
+
+int _CALLTYPE1 _heapchk(void)
+{
+	return(_heap_checkset((unsigned int)_HEAP_NOFILL));
+}
+
+/******************************************************************************/
+
+int _CALLTYPE1 _heapset (
+	unsigned int _fill
+	)
+{
+	return(_heap_checkset(_fill));
+}
+
+
+/***
+*static int _heap_checkset(_fill) - check the heap and fill in the
+*	free entries
+*
+*Purpose:
+*	Workhorse routine for both _heapchk() and _heapset().
+*
+*Entry:
+*	int _fill - either _HEAP_NOFILL or a value to be used as filler in
+*		    free entries
+*
+*Exit:
+*	See description of _heapchk()/_heapset()
+*
+*******************************************************************************/
+
+static int _CALLTYPE4 _heap_checkset (
+	unsigned int _fill
+	)
+{
+	REG1 _PBLKDESC pdesc;
+	REG2 _PBLKDESC pnext;
+	int roverfound=0;
+	int retval = _HEAPOK;
+
+	/*
+	 * lock the heap
+	 */
+
+	_mlock(_HEAP_LOCK);
+
+	/*
+	 * Validate the sentinel
+	 */
+
+	if (_heap_desc.sentinel.pnextdesc != NULL) {
+		_PRINTERR(_BADSENTINEL);
+		retval = _HEAPBADNODE;
+		goto done;
+	}
+
+	/*
+	 * Test for an empty heap
+	 */
+
+	if ( (_heap_desc.pfirstdesc == &_heap_desc.sentinel) &&
+	     (_heap_desc.proverdesc == &_heap_desc.sentinel) ) {
+		retval = _HEAPEMPTY;
+		goto done;
+	}
+
+	/*
+	 * Get and validate the first descriptor
+	 */
+
+	if ((pdesc = _heap_desc.pfirstdesc) == NULL) {
+		_PRINTERR(_EMPTYHEAP);
+		retval = _HEAPBADBEGIN;
+		goto done;
+	}
+
+	/*
+	 * Walk the heap descriptor list
+	 */
+
+	while (pdesc != &_heap_desc.sentinel) {
+
+		/*
+		 * Make sure address for this entry is in range.
+		 */
+
+		if ( (_ADDRESS(pdesc) < _ADDRESS(_heap_desc.pfirstdesc)) ||
+		     (_ADDRESS(pdesc) > _heap_desc.sentinel.pblock) ) {
+			_PRINTERR(_BADRANGE);
+			retval = _HEAPBADNODE;
+			goto done;
+		}
+
+		pnext = pdesc->pnextdesc;
+
+		/*
+		 * Make sure the blocks corresponding to pdesc and pnext are
+		 * in proper order.
+		 */
+
+		if ( _ADDRESS(pdesc) >= _ADDRESS(pnext) ) {
+			_PRINTERR(_BADORDER);
+			retval = _HEAPBADNODE;
+			goto done;
+		}
+
+		/*
+		 * Check the backpointer.
+		 */
+
+		if (_IS_INUSE(pdesc) || _IS_FREE(pdesc)) {
+
+			if (!_CHECK_PDESC(pdesc)) {
+				retval = _HEAPBADPTR;
+				goto done;
+			}
+		}
+
+		/*
+		 * Check for proverdesc
+		 */
+
+		if (pdesc == _heap_desc.proverdesc)
+			roverfound++;
+
+#ifdef	_OLDROVER_
+
+		/*
+		 * If it is free, make sure it doesn't precede the rover
+		 * block and fill it in if appropriate
+		 */
+
+		if ( _IS_FREE(pdesc) ) {
+
+			if ( roverfound == 0 ) {
+				_PRINTERR(_BADFREE);
+				retval = _HEAPBADNODE;
+				goto done;
+			}
+
+			if ( _fill != _HEAP_NOFILL )
+				memset( (void *)((unsigned)_ADDRESS(pdesc)+_HDRSIZE),
+				_fill, _BLKSIZE(pdesc) );
+		}
+
+#else	/* ndef _OLDROVER_ */
+
+		/*
+		 * If it is free, fill it in if appropriate
+		 */
+
+		if ( _IS_FREE(pdesc) && (_fill != _HEAP_NOFILL) )
+			memset( (void *)((unsigned)_ADDRESS(pdesc)+_HDRSIZE),
+			_fill, _BLKSIZE(pdesc) );
+
+#endif	/* _OLDROVER_ */
+
+		/*
+		 * Onto the next block
+		 */
+
+		pdesc = pnext;
+	}
+
+	/*
+	 * Make sure we found 1 and only 1 rover
+	 */
+
+	if (_heap_desc.proverdesc == &_heap_desc.sentinel)
+		roverfound++;
+
+	if (roverfound != 1) {
+		_PRINTERR(_BADROVER);
+		retval = _HEAPBADBEGIN;
+		goto done;
+	}
+
+	/*
+	 * Walk the empty list.  We can't really compare values against
+	 * anything but we may loop forever or may cause a fault.
+	 */
+
+	pdesc = _heap_desc.emptylist;
+
+	while (pdesc != NULL) {
+
+#ifdef DEBUG
+		if (pdesc->pblock != NULL) {
+			_PRINTERR(_BADEMPTY)
+			retval = _HEAPBADPTR;
+			goto done;
+		}
+#endif
+
+		pnext = pdesc->pnextdesc;
+
+		/*
+		 * Header should only appear once
+		 */
+
+		if (pnext == _heap_desc.emptylist) {
+			_PRINTERR(_EMPTYLOOP)
+			retval = _HEAPBADPTR;
+			goto done;
+		}
+
+		pdesc = pnext;
+
+	}
+
+
+	/*
+	 * Common return
+	 */
+
+done:
+	/*
+	 * release the heap lock
+	 */
+
+	_munlock(_HEAP_LOCK);
+
+	return(retval);
+
+}