From df992848f5aa803fcacd2c5e7d67034bb89e3fa3 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 26 Sep 2006 10:52:37 +0200 Subject: [PATCH] Fix pte_exec/mkexec and use it in change_page_attr() Fix the pte_exec/mkexec page table accessor functions to really use the NX bit. Previously they only checked the USER bit, but weren't actually used for anything. Then use them in change_page_attr() to manipulate the NX bit properly. Signed-off-by: Andi Kleen --- arch/x86_64/mm/pageattr.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/x86_64/mm/pageattr.c') diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c index 2685b1f3671c..01591b649f4e 100644 --- a/arch/x86_64/mm/pageattr.c +++ b/arch/x86_64/mm/pageattr.c @@ -190,10 +190,12 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) * lowmem */ if (__pa(address) < KERNEL_TEXT_SIZE) { unsigned long addr2; - pgprot_t prot2 = prot; + pgprot_t prot2; addr2 = __START_KERNEL_map + __pa(address); - pgprot_val(prot2) &= ~_PAGE_NX; - err = __change_page_attr(addr2, pfn, prot2, PAGE_KERNEL_EXEC); + /* Make sure the kernel mappings stay executable */ + prot2 = pte_pgprot(pte_mkexec(pfn_pte(0, prot))); + err = __change_page_attr(addr2, pfn, prot2, + PAGE_KERNEL_EXEC); } } up_write(&init_mm.mmap_sem); -- cgit v1.2.3-59-g8ed1b From 5e6b0bfe5b452957b7be4b6ef181cd41880f8359 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 26 Sep 2006 10:52:37 +0200 Subject: [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: Andi Kleen --- arch/x86_64/mm/pageattr.c | 16 ++++++---------- include/asm-x86_64/pgtable.h | 1 + 2 files changed, 7 insertions(+), 10 deletions(-) (limited to 'arch/x86_64/mm/pageattr.c') diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c index 01591b649f4e..3e231d762aaa 100644 --- a/arch/x86_64/mm/pageattr.c +++ b/arch/x86_64/mm/pageattr.c @@ -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); } @@ -119,32 +119,28 @@ __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; - set_pte(kpte,mk_pte(split, ref_prot2)); + set_pte(kpte, mk_pte(split, ref_prot2)); 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)--; diff --git a/include/asm-x86_64/pgtable.h b/include/asm-x86_64/pgtable.h index f7614670c655..b34f43acdef1 100644 --- a/include/asm-x86_64/pgtable.h +++ b/include/asm-x86_64/pgtable.h @@ -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; -- cgit v1.2.3-59-g8ed1b