Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH] [23/36] CPA: Make change_page_attr() more robust against use of PAT bits | Date | Wed, 16 Jan 2008 23:15:22 +0100 (CET) |
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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 <ak@suse.de> Acked-by: Jan Beulich <jbeulich@novell.com>
--- arch/x86/mm/pageattr_32.c | 4 ++-- arch/x86/mm/pageattr_64.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-)
Index: linux/arch/x86/mm/pageattr_32.c =================================================================== --- linux.orig/arch/x86/mm/pageattr_32.c +++ linux/arch/x86/mm/pageattr_32.c @@ -209,7 +209,7 @@ __change_page_attr(struct page *page, pg set_tlb_flush(address); if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) { - if (!pte_huge(*kpte)) { + if (level == 3) { set_pte_atomic(kpte, mk_pte(page, prot)); } else { pgprot_t ref_prot; @@ -225,7 +225,7 @@ __change_page_attr(struct page *page, pg kpte_page = split; } page_private(kpte_page)++; - } else if (!pte_huge(*kpte)) { + } else if (level == 3) { set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL)); BUG_ON(page_private(kpte_page) == 0); page_private(kpte_page)--; Index: linux/arch/x86/mm/pageattr_64.c =================================================================== --- linux.orig/arch/x86/mm/pageattr_64.c +++ linux/arch/x86/mm/pageattr_64.c @@ -184,7 +184,7 @@ __change_page_attr(unsigned long address set_tlb_flush(address); if (pgprot_val(prot) != pgprot_val(ref_prot)) { - if (!pte_huge(*kpte)) { + if (level == 4) { set_pte(kpte, pfn_pte(pfn, prot)); } else { /* @@ -201,7 +201,7 @@ __change_page_attr(unsigned long address kpte_page = split; } page_private(kpte_page)++; - } else if (!pte_huge(*kpte)) { + } else if (level == 4) { set_pte(kpte, pfn_pte(pfn, ref_prot)); BUG_ON(page_private(kpte_page) == 0); page_private(kpte_page)--;
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