klish/lub/heap/heap_tainted_memory.c

#include "string.h"

#include "private.h"
#include "context.h"

/* flag to indicate whether to taint memory or not */
static bool_t tainted = BOOL_FALSE;

/*--------------------------------------------------------- */
bool_t lub_heap_taint(bool_t enable)
{
	bool_t result = tainted;

	tainted = enable;

	return result;
}

/*--------------------------------------------------------- */
bool_t lub_heap_is_tainting(void)
{
	return tainted;
}

/*--------------------------------------------------------- */
void lub_heap_taint_memory(char *ptr, lub_heap_taint_t type, size_t size)
{
	if (BOOL_TRUE == tainted) {
#ifdef __vxworks
		extern function_t taskDestroy;	/* fiddle a reference to the function ... */
		extern function_t taskSuspend;	/* ...and the next function in the library */
		/* 
		 * VxWorks taskDestroy() relies on being able to access
		 * free memory.
		 * It calls objFree() followed by objTerminate() !!!!
		 * So we have to perform a crufty hack to avoid this
		 * mistake blowing us out of the water...
		 */
		if (LUB_HEAP_TAINT_FREE == type) {
			int i;
			/* obtain the backtrace of the stack */
			stackframe_t frame;
			lub_heap__get_stackframe(&frame, 10);
			for (i = 0; i < 10; i++) {
				function_t *address = frame.backtrace[i];
				if ((address > &taskDestroy)
				    && (address < &taskSuspend)) {
					return;
				}
			}
		}
#endif				/* __vxworks */
		/* taint the memory */
		memset(ptr, type, size);
	}
}

/*--------------------------------------------------------- */