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Commit 5e6b0bfe authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
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[PATCH] Use proper accessors to change PSE bits in change_page_attr() 



Use normal pte accessors in change_page_attr() to access the PSE
bits.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent df992848

arch/x86_64/mm/pageattr.c

+6 −10
Original line number Diff line number Diff line
@@ -108,8 +108,8 @@ static void revert_page(unsigned long address, pgprot_t ref_prot) 
	BUG_ON(pud_none(*pud));

	pmd = pmd_offset(pud, address);

	BUG_ON(pmd_val(*pmd) & _PAGE_PSE);

	pgprot_val(ref_prot) |= _PAGE_PSE;

	large_pte = mk_pte_phys(__pa(address) & LARGE_PAGE_MASK, ref_prot);

	large_pte = pte_mkhuge(large_pte);

	set_pte((pte_t *)pmd, large_pte);

}
@@ -119,24 +119,20 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, 
{ 

	pte_t *kpte; 

	struct page *kpte_page;

	unsigned kpte_flags;

	pgprot_t ref_prot2;

	kpte = lookup_address(address);

	if (!kpte) return 0;

	kpte_page = virt_to_page(((unsigned long)kpte) & PAGE_MASK);

	kpte_flags = pte_val(*kpte); 

	if (pgprot_val(prot) != pgprot_val(ref_prot)) { 

		if ((kpte_flags & _PAGE_PSE) == 0) { 

		if (!pte_huge(*kpte)) {

			set_pte(kpte, pfn_pte(pfn, prot));

		} else {

 			/*

			 * split_large_page will take the reference for this

			 * change_page_attr on the split page.

 			 */



			struct page *split;

			ref_prot2 = __pgprot(pgprot_val(pte_pgprot(*lookup_address(address))) & ~(1<<_PAGE_BIT_PSE));



			ref_prot2 = pte_pgprot(pte_clrhuge(*kpte));

			split = split_large_page(address, prot, ref_prot2);

			if (!split)

				return -ENOMEM;
@@ -144,7 +140,7 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, 
			kpte_page = split;

		}

		page_private(kpte_page)++;

	} else if ((kpte_flags & _PAGE_PSE) == 0) { 

	} else if (!pte_huge(*kpte)) {

		set_pte(kpte, pfn_pte(pfn, ref_prot));

		BUG_ON(page_private(kpte_page) == 0);

		page_private(kpte_page)--;

include/asm-x86_64/pgtable.h

+1 −0
Original line number Diff line number Diff line
@@ -283,6 +283,7 @@ static inline pte_t pte_mkdirty(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | 
static inline pte_t pte_mkyoung(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) | _PAGE_ACCESSED)); return pte; }

static inline pte_t pte_mkwrite(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) | _PAGE_RW)); return pte; }

static inline pte_t pte_mkhuge(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) | _PAGE_PSE)); return pte; }

static inline pte_t pte_clrhuge(pte_t pte)	{ set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_PSE)); return pte; }



struct vm_area_struct;