[PATCH] powerpc: fix idr locking in init_new_context

[Sonny Rao]

We always need to serialize accesses to mmu_context_idr.

I hit this bug when testing with a small number of mmu contexts.


Signed-off-by: Sonny Rao <sonny at burdell.org>

--- a/arch/powerpc/mm/mmu_context_64.c
+++ b/arch/powerpc/mm/mmu_context_64.c
@@ -44,7 +44,9 @@ again:
                return err;
 
        if (index > MAX_CONTEXT) {
+               spin_lock(&mmu_context_lock);
                idr_remove(&mmu_context_idr, index);
+               spin_unlock(&mmu_context_lock);
                return -ENOMEM;
        }