Commit 55ca2263 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

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: 9e343b46 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: default avatarWill Deacon <will@kernel.org>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ffc3714334c3bfaca6f13788ad039e8759ae413f.1592225558.git.christophe.leroy@csgroup.eu
parent 1497eea6

mm/gup.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

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