mm/gup: Use huge_ptep_get() in gup_hugepte()

gup_hugepte() reads hugepage table entries, it can't read them directly, huge_ptep_get() must be used. Fixes: 9e343b4 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses") Signed-off-by: Christophe Leroy <[email protected]> Acked-by: Will Deacon <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/ffc3714334c3bfaca6f13788ad039e8759ae413f.1592225558.git.christophe.leroy@csgroup.eu
kawasaki · Jun 20, 2020 · 55ca226 · 55ca226
1 parent 1497eea
commit 55ca226
Showing 1 changed file with 1 addition and 1 deletion.
diff --git 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;