[RFC PATCH 2/3] powerpc/mm/hugetlb: Fix kernel crash if we fail to allocate page table caches
From: Aneesh Kumar K.V <hidden>
Date: 2019-05-14 14:53:38
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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 <redacted> --- 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