1 files changed, 27 insertions, 0 deletions
diff --git a/sys/memdbg/mgtfwa.x b/sys/memdbg/mgtfwa.x
new file mode 100644
index 00000000..9b39f6eb
--- /dev/null
+++ b/sys/memdbg/mgtfwa.x
@@ -0,0 +1,27 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<syserr.h>
+include	<config.h>
+include	<mach.h>
+
+# MGTFWA -- Given a user buffer pointer, retrieve physical address of buffer.
+# If physical address of buffer does not seem reasonable, memory has probably
+# been overwritten, a fatal error.
+
+int procedure mgtfwa (ptr, dtype)
+
+pointer	ptr, bufptr
+int	dtype
+int	locbuf, fwa
+int	coerce()
+
+begin
+	bufptr = coerce (ptr, dtype, TY_INT)
+	fwa = Memi[bufptr-1]
+	call zlocva (Memi[bufptr-1], locbuf)
+
+	if (abs (locbuf - fwa) > SZ_VMEMALIGN)
+	    call sys_panic (SYS_MCORRUPTED, "Memory has been corrupted")
+
+	return (fwa)
+end