[RFC PATCH 2/3] powerpc/mm/hugetlb: Fix kernel crash if we fail to allocate page table caches

[Aneesh Kumar K.V]

We only check for hugetlb allocations, because with hugetlb we do conditional
registration. For PGD/PUD/PMD levels we register them always in
pgtable_cache_init.
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
 arch/powerpc/mm/hugetlbpage.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index ae9d71da5219..ee16a3fb788a 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -61,12 +61,17 @@ static int __hugepte_alloc(struct mm_struct *mm, hugepd_t 
*hpdp,
                num_hugepd = 1;
        }
 
+       if (!cachep) {
+               WARN_ONCE(1, "No page table cache created for hugetlb tables");
+               return -ENOMEM;
+       }
+
        new = kmem_cache_alloc(cachep, pgtable_gfp_flags(mm, GFP_KERNEL));
 
        BUG_ON(pshift > HUGEPD_SHIFT_MASK);
        BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK);
 
-       if (! new)
+       if (!new)
                return -ENOMEM;
 
        /*
-- 
2.21.0