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Subject[PATCH 1/3] mm/gup: Use huge_ptep_get() in gup_hugepte()
Date
gup_hugepte() reads hugepage table entries, it can't read
them directly, huge_ptep_get() must be used.

Fixes: 2ab3a0a02905 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
mm/gup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/gup.c b/mm/gup.c
index de9e36262ccb..761df4944ef5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2425,7 +2425,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
if (pte_end < end)
end = pte_end;

- pte = READ_ONCE(*ptep);
+ pte = huge_ptep_get(ptep);

if (!pte_access_permitted(pte, flags & FOLL_WRITE))
return 0;
--
2.25.0
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