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From: Kip Macy <kmacy@FreeBSD.org>
To: Perforce Change Reviews <perforce@freebsd.org>
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Subject: PERFORCE change 132284 for review
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http://perforce.freebsd.org/chv.cgi?CH=132284

Change 132284 by kmacy@pandemonium:kmacy:xen31 on 2008/01/02 04:12:09

	add sanity checks in initialization sequence

Affected files ...

.. //depot/projects/xen31/sys/dev/xen/blkfront/blkfront.c#7 edit

Differences ...

==== //depot/projects/xen31/sys/dev/xen/blkfront/blkfront.c#7 (text+ko) ====

@@ -236,6 +236,7 @@
 {
 	int err, vdevice, i;
 	struct blkfront_info *info;
+	
 
 	/* FIXME: Use dynamic device id if this is not set. */
 	err = xenbus_scanf(XBT_NIL, dev->nodename,
@@ -250,6 +251,15 @@
 		xenbus_dev_fatal(dev, ENOMEM, "allocating info structure");
 		return ENOMEM;
 	}
+	
+	/*
+	 * XXX debug only
+	 */
+	for (i = 0; i < sizeof(*info); i++)
+			if (((uint8_t *)info)[i] != 0)
+					panic("non-null memory");
+
+	info->shadow_free = 0;
 	info->xbdev = dev;
 	info->vdevice = vdevice;
 	info->connected = BLKIF_STATE_DISCONNECTED;
@@ -518,11 +528,12 @@
 static inline int 
 GET_ID_FROM_FREELIST(struct blkfront_info *info)
 {
-	unsigned long free = info->shadow_free;
-	KASSERT(free <= BLK_RING_SIZE, ("free %lu > RING_SIZE", free));
-	info->shadow_free = info->shadow[free].req.id;
-	info->shadow[free].req.id = 0x0fffffee; /* debug */
-	return free;
+	unsigned long nfree = info->shadow_free;
+	
+	KASSERT(nfree <= BLK_RING_SIZE, ("free %lu > RING_SIZE", nfree));
+	info->shadow_free = info->shadow[nfree].req.id;
+	info->shadow[nfree].req.id = 0x0fffffee; /* debug */
+	return nfree;
 }
 
 static inline void