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authorAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>2018-09-20 21:09:45 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2018-10-03 08:39:59 +0300
commit75646c480fdeffbc246e9d45f29721ab5569f921 (patch)
treeed26173ab5f73c56889d0f61a70715e52acd679c
parentae28f17b5eeb6702427ccb59e32e32a0c7e02f6b (diff)
downloadlinux-75646c480fdeffbc246e9d45f29721ab5569f921.tar.xz
arch/powerpc/mm/hash: validate the pte entries before handling the hash fault
Make sure we are operating on THP and hugetlb entries in the respective hash fault handling routines. No functional change in this patch. If we walked the table wrongly before, we will retry the access. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/mm/hugepage-hash64.c6
-rw-r--r--arch/powerpc/mm/hugetlbpage-hash64.c4
2 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c
index 01f213d2bcb9..dfbc3b32f09b 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -51,6 +51,12 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
new_pmd |= _PAGE_DIRTY;
} while (!pmd_xchg(pmdp, __pmd(old_pmd), __pmd(new_pmd)));
+ /*
+ * Make sure this is thp or devmap entry
+ */
+ if (!(old_pmd & (H_PAGE_THP_HUGE | _PAGE_DEVMAP)))
+ return 0;
+
rflags = htab_convert_pte_flags(new_pmd);
#if 0
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index b320f5097a06..2e6a8f9345d3 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -62,6 +62,10 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
new_pte |= _PAGE_DIRTY;
} while(!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
+ /* Make sure this is a hugetlb entry */
+ if (old_pte & (H_PAGE_THP_HUGE | _PAGE_DEVMAP))
+ return 0;
+
rflags = htab_convert_pte_flags(new_pte);
if (unlikely(mmu_psize == MMU_PAGE_16G))
offset = PTRS_PER_PUD;