[PATCH 3.13 017/187] sparc64: Fix bugs in get_user_pages_fast() wrt. THP.

Kamal Mostafa
2014-09-15T22:10:40Z

From: "David S. Miller" <davem@davemloft.net>

[ Upstream commit 04df419de34104d8818b8c5cffaa062fa36d20ea ]

The large PMD path needs to check _PAGE_VALID not _PAGE_PRESENT, to
decide if it needs to bail and return 0.

pmd_large() should therefore just check _PAGE_PMD_HUGE.

Calls to gup_huge_pmd() are guarded with a check of pmd_large(), so we
just need to add a valid bit check.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
arch/sparc/include/asm/pgtable_64.h | 2 +-
arch/sparc/mm/gup.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index e3db4b8..1f28103 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -633,7 +633,7 @@ static inline unsigned long pmd_large(pmd_t pmd)
{
pte_t pte = __pte(pmd_val(pmd));

- return (pte_val(pte) & _PAGE_PMD_HUGE) && pte_present(pte);
+ return pte_val(pte) & _PAGE_PMD_HUGE;
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/arch/sparc/mm/gup.c b/arch/sparc/mm/gup.c
index c4d3da6..1aed043 100644
--- a/arch/sparc/mm/gup.c
+++ b/arch/sparc/mm/gup.c
@@ -73,7 +73,7 @@ static int gup_huge_pmd(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
struct page *head, *page, *tail;
int refs;

- if (!pmd_large(pmd))
+ if (!(pmd_val(pmd) & _PAGE_VALID))
return 0;

if (write && !pmd_write(pmd))
--
1.9.1