Commit 69dde4c5 authored Feb 18, 2013 by Catalin Marinas Committed by Russell King Feb 21, 2013

ARM: 7654/1: Preserve L_PTE_VALID in pte_modify()



Following commit 26ffd0d4 (ARM: mm: introduce present, faulting entries
for PAGE_NONE), if a page has been mapped as PROT_NONE, the L_PTE_VALID
bit is cleared by the set_pte_ext() code. With LPAE the software and
hardware pte share the same location and subsequent modifications of pte
range (change_protection()) will leave the L_PTE_VALID bit cleared.

This patch adds the L_PTE_VALID bit to the newprot mask in pte_modify().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Subash Patel <subash.rp@samsung.com>
Tested-by: Subash Patel <subash.rp@samsung.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org> # 3.8.x
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 70264367

arch/arm/include/asm/pgtable.h

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -240,7 +240,8 @@ static inline pte_t pte_mkspecial(pte_t pte) { return pte; }

	static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)		static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
	{		{
	const pteval_t mask = L_PTE_XN \| L_PTE_RDONLY \| L_PTE_USER \| L_PTE_NONE;		const pteval_t mask = L_PTE_XN \| L_PTE_RDONLY \| L_PTE_USER \|
			L_PTE_NONE \| L_PTE_VALID;
	pte_val(pte) = (pte_val(pte) & ~mask) \| (pgprot_val(newprot) & mask);		pte_val(pte) = (pte_val(pte) & ~mask) \| (pgprot_val(newprot) & mask);
	return pte;		return pte;
	}		}