4.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Catalin Marinas <[email protected]>

commit 5bb1cc0ff9a6b68871970737e6c4c16919928d8b upstream.

Currently, pmd_present() only checks for a non-zero value, returning
true even after pmd_mknotpresent() (which only clears the type bits).
This patch converts pmd_present() to using pte_present(), similar to the
other pmd_*() checks. As a side effect, it will return true for
PROT_NONE mappings, though they are not yet used by the kernel with
transparent huge pages.

For consistency, also change pmd_mknotpresent() to only clear the
PMD_SECT_VALID bit, even though the PMD_TABLE_BIT is already 0 for block
mappings (no functional change). The unused PMD_SECT_PROT_NONE
definition is removed as transparent huge pages use the pte page prot
values.

Fixes: 9c7e535fcc17 ("arm64: mm: Route pmd thp functions through pte 
equivalents")
Reviewed-by: Will Deacon <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/arm64/include/asm/pgtable-hwdef.h |    1 -
 arch/arm64/include/asm/pgtable.h       |    4 ++--
 2 files changed, 2 insertions(+), 3 deletions(-)

--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -133,7 +133,6 @@
  * Section
  */
 #define PMD_SECT_VALID         (_AT(pmdval_t, 1) << 0)
-#define PMD_SECT_PROT_NONE     (_AT(pmdval_t, 1) << 58)
 #define PMD_SECT_USER          (_AT(pmdval_t, 1) << 6)         /* AP[1] */
 #define PMD_SECT_RDONLY                (_AT(pmdval_t, 1) << 7)         /* 
AP[2] */
 #define PMD_SECT_S             (_AT(pmdval_t, 3) << 8)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -356,6 +356,7 @@ static inline pgprot_t mk_sect_prot(pgpr
 #define pmd_trans_huge(pmd)    (pmd_val(pmd) && !(pmd_val(pmd) & 
PMD_TABLE_BIT))
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+#define pmd_present(pmd)       pte_present(pmd_pte(pmd))
 #define pmd_dirty(pmd)         pte_dirty(pmd_pte(pmd))
 #define pmd_young(pmd)         pte_young(pmd_pte(pmd))
 #define pmd_wrprotect(pmd)     pte_pmd(pte_wrprotect(pmd_pte(pmd)))
@@ -364,7 +365,7 @@ static inline pgprot_t mk_sect_prot(pgpr
 #define pmd_mkclean(pmd)       pte_pmd(pte_mkclean(pmd_pte(pmd)))
 #define pmd_mkdirty(pmd)       pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 #define pmd_mkyoung(pmd)       pte_pmd(pte_mkyoung(pmd_pte(pmd)))
-#define pmd_mknotpresent(pmd)  (__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
+#define pmd_mknotpresent(pmd)  (__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
 
 #define __HAVE_ARCH_PMD_WRITE
 #define pmd_write(pmd)         pte_write(pmd_pte(pmd))
@@ -403,7 +404,6 @@ extern pgprot_t phys_mem_access_prot(str
                                     unsigned long size, pgprot_t vma_prot);
 
 #define pmd_none(pmd)          (!pmd_val(pmd))
-#define pmd_present(pmd)       (pmd_val(pmd))
 
 #define pmd_bad(pmd)           (!(pmd_val(pmd) & 2))
 


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