[PATCH] powerpc: pseries_remove_lmb() should validate pfn

[Nathan Fontenot]

The pfn of the memory to be removed should be validated prior to
attempting to remove the memory.  In cases where the probe of a
memory section fails during hotplug add, the pfn for the lmb may
not be valid.

Signed-off-by: Badari Pulavarty <pbadari at us.ibm.com>
Signed-off-by: Nathan Fontenot <nfont at austin.ibm.com>

---

--- linux-2.6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c	2008-10-01 14:20:08.000000000 -0500
+++ linux-2.6/arch/powerpc/platforms/pseries/hotplug-memory.c	2008-10-13 13:19:49.000000000 -0500
@@ -22,6 +22,12 @@
 	int ret;
 
 	start_pfn = base >> PAGE_SHIFT;
+
+	if (!pfn_valid(start_pfn)) {
+		lmb_remove(base, lmb_size);
+		return 0;
+	}
+
 	zone = page_zone(pfn_to_page(start_pfn));
 
 	/*