From 895bdc29956e5c9e9e101b2b1c2f0ed34130f945 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 30 Jan 2008 13:33:52 +0100 Subject: [PATCH] x86: c_p_a() make it more robust against use of PAT bits Use the page table level instead of the PSE bit to check if the PTE is for a 4K page or not. This makes the code more robust when the PAT bit is changed because the PAT bit on 4K pages is in the same position as the PSE bit. Signed-off-by: Andi Kleen Acked-by: Jan Beulich Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/pageattr_32.c | 4 ++-- arch/x86/mm/pageattr_64.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/pageattr_32.c b/arch/x86/mm/pageattr_32.c index 5cb5c71..66688a6 100644 --- a/arch/x86/mm/pageattr_32.c +++ b/arch/x86/mm/pageattr_32.c @@ -172,7 +172,7 @@ static int __change_page_attr(struct page *page, pgprot_t prot) BUG_ON(PageCompound(kpte_page)); if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) { - if (!pte_huge(*kpte)) { + if (level == 3) { set_pte_atomic(kpte, mk_pte(page, prot)); } else { struct page *split; @@ -190,7 +190,7 @@ static int __change_page_attr(struct page *page, pgprot_t prot) } page_private(kpte_page)++; } else { - if (!pte_huge(*kpte)) { + if (level == 3) { set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL)); BUG_ON(page_private(kpte_page) == 0); page_private(kpte_page)--; diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c index 3ccdb14..73dbbb4 100644 --- a/arch/x86/mm/pageattr_64.c +++ b/arch/x86/mm/pageattr_64.c @@ -153,7 +153,7 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, BUG_ON(PageLRU(kpte_page)); BUG_ON(PageCompound(kpte_page)); if (pgprot_val(prot) != pgprot_val(ref_prot)) { - if (!pte_huge(*kpte)) { + if (level == 4) { set_pte(kpte, pfn_pte(pfn, prot)); } else { /* @@ -172,7 +172,7 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, } page_private(kpte_page)++; } else { - if (!pte_huge(*kpte)) { + if (level == 4) { set_pte(kpte, pfn_pte(pfn, ref_prot)); BUG_ON(page_private(kpte_page) == 0); page_private(kpte_page)--; -- 2.7.4