PERFORCE change 219901 for review

[Brooks Davis]

http://p4web.freebsd.org/@@219901?ac=10

Change 219901 by brooks at brooks_zenith on 2012/12/13 16:38:36

	Prefault the stack and heap by zeroing them.  This signficantly
	reduces the runtime of the first invocation of libmagic sandboxes.

Affected files ...

.. //depot/projects/ctsrd/cheribsd/src/lib/libcheri/sandbox.c#3 edit

Differences ...

==== //depot/projects/ctsrd/cheribsd/src/lib/libcheri/sandbox.c#3 (text+ko) ====

@@ -174,6 +174,7 @@
 		warn("%s: mmap heap", __func__);
 		goto error;
 	}
+	memset(base, 0, sb->sb_heaplen);
 	base += sb->sb_heaplen;
 	length -= sb->sb_heaplen;
 
@@ -192,6 +193,7 @@
 		warn("%s: mmap stack", __func__);
 		goto error;
 	}
+	memset(base, 0, length);
 	base += STACK_SIZE;
 	length -= STACK_SIZE;