From d8f8f5564f4a5d2f075eb2c6554eebab52927fe7 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 5cb5c7101f413..66688a630839e 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 3ccdb1401e673..73dbbb4048e66 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)--; -- 2.39.5