--- /dev/null
+++ xnu/xnu-792.22.5/libkern/gen/OSDebug.cpp
@@ -0,0 +1,195 @@
+/*
+ * Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+// NOTE:  This file is only c++ so I can get static initialisers going
+#include <libkern/OSDebug.h>
+
+#include <sys/cdefs.h>
+
+#include <stdarg.h>
+#include <mach/mach_types.h>
+#include <mach/kmod.h>
+#include <kern/lock.h>
+
+#include <libkern/libkern.h>	// From bsd's libkern directory
+#include <mach/vm_param.h>
+
+__BEGIN_DECLS
+// From osmfk/kern/thread.h but considered to be private
+extern vm_offset_t min_valid_stack_address(void);
+extern vm_offset_t max_valid_stack_address(void);
+
+// From osfmk/kmod.c
+extern void kmod_dump_log(vm_offset_t *addr, unsigned int cnt);
+
+extern addr64_t kvtophys(vm_offset_t va);
+__END_DECLS
+
+static mutex_t *sOSReportLock = mutex_alloc(0);
+
+/* Report a message with a 4 entry backtrace - very slow */
+void
+OSReportWithBacktrace(const char *str, ...)
+{
+    char buf[128];
+    void *bt[9];
+    const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
+    va_list listp;
+
+    // Ignore the our and our callers stackframes, skipping frames 0 & 1
+    (void) OSBacktrace(bt, cnt);
+
+    va_start(listp, str);
+    vsnprintf(buf, sizeof(buf), str, listp);
+    va_end(listp);
+
+    mutex_lock(sOSReportLock);
+    {
+	printf("%s\nBacktrace %p %p %p %p %p %p %p\n",
+		buf, bt[2], bt[3], bt[4], bt[5], bt[6], bt[7], bt[8]);
+	kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2);
+    }
+    mutex_unlock(sOSReportLock);
+}
+
+static vm_offset_t minstackaddr = min_valid_stack_address();
+static vm_offset_t maxstackaddr = max_valid_stack_address();
+
+#if __i386__
+#define i386_RETURN_OFFSET 4
+
+static unsigned int
+i386_validate_stackptr(vm_offset_t stackptr)
+{
+	/* Existence and alignment check
+	 */
+	if (!stackptr || (stackptr & 0x3))
+		return 0;
+  
+	/* Is a virtual->physical translation present?
+	 */
+	if (!kvtophys(stackptr))
+		return 0;
+  
+	/* Check if the return address lies on the same page;
+	 * If not, verify that a translation exists.
+	 */
+	if (((PAGE_SIZE - (stackptr & PAGE_MASK)) < i386_RETURN_OFFSET) &&
+	    !kvtophys(stackptr + i386_RETURN_OFFSET))
+		return 0;
+	return 1;
+}
+
+static unsigned int
+i386_validate_raddr(vm_offset_t raddr)
+{
+	return ((raddr > VM_MIN_KERNEL_ADDRESS) &&
+	    (raddr < VM_MAX_KERNEL_ADDRESS));
+}
+#endif
+
+unsigned OSBacktrace(void **bt, unsigned maxAddrs)
+{
+    unsigned frame;
+
+#if __ppc__
+    vm_offset_t stackptr, stackptr_prev;
+    const vm_offset_t * const mem = (vm_offset_t *) 0;
+    unsigned i = 0;
+
+    __asm__ volatile("mflr %0" : "=r" (stackptr)); 
+    bt[i++] = (void *) stackptr;
+
+    __asm__ volatile("mr %0,r1" : "=r" (stackptr)); 
+    for ( ; i < maxAddrs; i++) {
+	// Validate we have a reasonable stackptr
+	if ( !(minstackaddr <= stackptr && stackptr < maxstackaddr)
+	|| (stackptr & 3))
+	    break;
+
+	stackptr_prev = stackptr;
+	stackptr = mem[stackptr_prev >> 2];
+	if ((stackptr_prev ^ stackptr) > 8 * 1024)	// Sanity check
+	    break;
+
+	vm_offset_t addr = mem[(stackptr >> 2) + 2]; 
+	if ((addr & 3) || (addr < 0x8000))	// More sanity checks
+	    break;
+	bt[i] = (void *) addr;
+    }
+    frame = i;
+
+    for ( ; i < maxAddrs; i++)
+	    bt[i] = (void *) 0;
+#elif __i386__
+#define SANE_i386_FRAME_SIZE 8*1024
+    vm_offset_t stackptr, stackptr_prev, raddr;
+    unsigned frame_index = 0;
+/* Obtain current frame pointer */
+    __asm__ volatile("movl %%ebp, %0" : "=m" (stackptr)); 
+
+    if (!i386_validate_stackptr(stackptr))
+	    goto pad;
+
+    raddr = *((vm_offset_t *) (stackptr + i386_RETURN_OFFSET));
+
+    if (!i386_validate_raddr(raddr))
+	    goto pad;
+
+    bt[frame_index++] = (void *) raddr;
+
+    for ( ; frame_index < maxAddrs; frame_index++) {
+	    stackptr_prev = stackptr;
+	    stackptr = *((vm_offset_t *) stackptr_prev);
+
+	    if (!i386_validate_stackptr(stackptr))
+		    break;
+	/* Stack grows downwards */
+	    if (stackptr < stackptr_prev)
+		    break;
+
+	    if ((stackptr_prev ^ stackptr) > SANE_i386_FRAME_SIZE)
+		    break;
+
+	    raddr = *((vm_offset_t *) (stackptr + i386_RETURN_OFFSET));
+
+	    if (!i386_validate_raddr(raddr))
+		    break;
+
+	    bt[frame_index] = (void *) raddr;
+    }
+pad:
+    frame = frame_index;
+
+    for ( ; frame_index < maxAddrs; frame_index++)
+	    bt[frame_index] = (void *) 0;
+#else
+#error arch
+#endif
+    return frame;
+}