powerpc/64e: Fix wrong test in __ptep_test_and_clear_young()

[ Upstream commit 5ea0bbaa32e8f54e9a57cfee4a3b8769b80be0d2 ]

Commit 45201c879469 ("powerpc/nohash: Remove hash related code from
nohash headers.") replaced:

  if ((pte_val(*ptep) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
	return 0;

By:

  if (pte_young(*ptep))
	return 0;

But it should be:

  if (!pte_young(*ptep))
	return 0;

Fix it.

Fixes: 45201c879469 ("powerpc/nohash: Remove hash related code from nohash headers.")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/8bb7f06494e21adada724ede47a4c3d97e879d40.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index 879e9a6e5a870a49c1dbd5f8c37ac5086f359b22..00a003d36752346bf4b1d17de50384a5e2a3213c 100644 (file)
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -197,7 +197,7 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
 {
        unsigned long old;
 
-       if (pte_young(*ptep))
+       if (!pte_young(*ptep))
                return 0;
        old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0);
        return (old & _PAGE_ACCESSED) != 0;