From: Bibo Mao <maobibo@loongson.cn>
Date: Wed, 27 May 2020 02:25:20 +0000 (+0800)
Subject: MIPS: mm: add page valid judgement in function pte_modify
X-Git-Tag: v5.8-rc1~173^2~12
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=273b5fa00fadabd587fac858ea61a17b3653892d;p=thirdparty%2Fkernel%2Flinux.git

MIPS: mm: add page valid judgement in function pte_modify

If original PTE has _PAGE_ACCESSED bit set, and new pte has no
_PAGE_NO_READ bit set, we can add _PAGE_SILENT_READ bit to enable
page valid bit.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
---

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index d9772aff2f02e..85b39c9fd09ec 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -532,8 +532,11 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 #else
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
-	return __pte((pte_val(pte) & _PAGE_CHG_MASK) |
-		     (pgprot_val(newprot) & ~_PAGE_CHG_MASK));
+	pte_val(pte) &= _PAGE_CHG_MASK;
+	pte_val(pte) |= pgprot_val(newprot) & ~_PAGE_CHG_MASK;
+	if ((pte_val(pte) & _PAGE_ACCESSED) && !(pte_val(pte) & _PAGE_NO_READ))
+		pte_val(pte) |= _PAGE_SILENT_READ;
+	return pte;
 }
 #endif