[PATCH] ARM: update __swp_entry_to_pte() to use PTE_TYPE_FAULT

From: Russell King
Date: Thu May 13 2021 - 07:27:53 EST


Swap entries use a faulting PTE which have the least two significant
bits as zero. Due to this, the use of PTE_TYPE_FAULT was overlooked,
but really should have been included in __swp_entry_to_pte().

Convert this macro to use PTE_TYPE_FAULT to properly document what is
going on here, and use __pte() to convert the swp_entry_t to a pte_t.

This results in no change to the resulting kernel text.

Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
---
arch/arm/include/asm/pgtable.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index c02f24400369..c43e07d6046d 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -303,7 +303,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })

#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
-#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
+#define __swp_entry_to_pte(swp) __pte((swp).val | PTE_TYPE_FAULT)

/*
* It is an error for the kernel to have more swap files than we can
--
2.20.1