Linux-libre 4.4-gnupck-4.4-gnu

1 files changed, 35 insertions, 5 deletions

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 06c14523b..9833fee49 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -89,6 +89,25 @@ int pgd_huge(pgd_t pgd)
 	 */
 	return ((pgd_val(pgd) & 0x3) != 0x0);
 }
+
+#if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_DEBUG_VM)
+/*
+ * This enables us to catch the wrong page directory format
+ * Moved here so that we can use WARN() in the call.
+ */
+int hugepd_ok(hugepd_t hpd)
+{
+	bool is_hugepd;
+
+	/*
+	 * We should not find this format in page directory, warn otherwise.
+	 */
+	is_hugepd = (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
+	WARN(is_hugepd, "Found wrong page directory format\n");
+	return 0;
+}
+#endif
+
 #else
 int pmd_huge(pmd_t pmd)
 {
@@ -109,7 +128,7 @@ int pgd_huge(pgd_t pgd)
 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
 {
 	/* Only called for hugetlbfs pages, hence can ignore THP */
-	return __find_linux_pte_or_hugepte(mm->pgd, addr, NULL);
+	return __find_linux_pte_or_hugepte(mm->pgd, addr, NULL, NULL);
 }
 
 static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
@@ -684,13 +703,14 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 struct page *
 follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
 {
+	bool is_thp;
 	pte_t *ptep, pte;
 	unsigned shift;
 	unsigned long mask, flags;
 	struct page *page = ERR_PTR(-EINVAL);
 
 	local_irq_save(flags);
-	ptep = find_linux_pte_or_hugepte(mm->pgd, address, &shift);
+	ptep = find_linux_pte_or_hugepte(mm->pgd, address, &is_thp, &shift);
 	if (!ptep)
 		goto no_page;
 	pte = READ_ONCE(*ptep);
@@ -699,7 +719,7 @@ follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
 	 * Transparent hugepages are handled by generic code. We can skip them
 	 * here.
 	 */
-	if (!shift || pmd_trans_huge(__pmd(pte_val(pte))))
+	if (!shift || is_thp)
 		goto no_page;
 
 	if (!pte_present(pte)) {
@@ -956,7 +976,7 @@ void flush_dcache_icache_hugepage(struct page *page)
  */
 
 pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
-				   unsigned *shift)
+				   bool *is_thp, unsigned *shift)
 {
 	pgd_t pgd, *pgdp;
 	pud_t pud, *pudp;
@@ -968,6 +988,9 @@ pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
 	if (shift)
 		*shift = 0;
 
+	if (is_thp)
+		*is_thp = false;
+
 	pgdp = pgdir + pgd_index(ea);
 	pgd  = READ_ONCE(*pgdp);
 	/*
@@ -1015,7 +1038,14 @@ pte_t *__find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
 			if (pmd_none(pmd))
 				return NULL;
 
-			if (pmd_huge(pmd) || pmd_large(pmd)) {
+			if (pmd_trans_huge(pmd)) {
+				if (is_thp)
+					*is_thp = true;
+				ret_pte = (pte_t *) pmdp;
+				goto out;
+			}
+
+			if (pmd_huge(pmd)) {
 				ret_pte = (pte_t *) pmdp;
 				goto out;
 			} else if (is_hugepd(__hugepd(pmd_val(pmd))))