[PPC64] Hugepage bugfix

[David Gibson]

Andrew, Linus, please apply:

Fix a stupid unbalanced lock bug in the ppc64 hugepage code.  Lead
rapidly to a crash if both CONFIG_HUGETLB_PAGE and CONFIG_PREEMPT were
enabled (even without actually using hugepages at all).

Signed-off-by: David Gibson <dwg at au1.ibm.com>

Index: working-2.6/arch/ppc64/mm/hugetlbpage.c
===================================================================
--- working-2.6.orig/arch/ppc64/mm/hugetlbpage.c	2005-01-06 10:47:48.000000000 +1100
+++ working-2.6/arch/ppc64/mm/hugetlbpage.c	2005-01-10 15:16:25.142319552 +1100
@@ -745,7 +745,7 @@
 
 	pgdir = mm->context.huge_pgdir;
 	if (! pgdir)
-		return;
+		goto out;
 
 	mm->context.huge_pgdir = NULL;
 
@@ -768,6 +768,7 @@
 	BUG_ON(memcmp(pgdir, empty_zero_page, PAGE_SIZE));
 	kmem_cache_free(zero_cache, pgdir);
 
+ out:
 	spin_unlock(&mm->page_table_lock);
 }
 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist.  NOT _the_ _other_ _way_
				| _around_!
http://www.ozlabs.org/people/dgibson