From 34eff1d75b26eac5c04f9c5b52ba9e3bf1dd8877 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 30 Jan 2008 13:34:01 +0100 Subject: [PATCH] x86: simplify __change_page_attr() Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/mm/pageattr_64.c | 47 +++++++++++++++------------------------ 1 file changed, 18 insertions(+), 29 deletions(-) diff --git a/arch/x86/mm/pageattr_64.c b/arch/x86/mm/pageattr_64.c index cbded8300e36..5eff244c16db 100644 --- a/arch/x86/mm/pageattr_64.c +++ b/arch/x86/mm/pageattr_64.c @@ -67,8 +67,7 @@ split_large_page(unsigned long address, pgprot_t ref_prot) } static int -__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot, - pgprot_t ref_prot) +__change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot) { struct page *kpte_page; pte_t *kpte; @@ -84,32 +83,24 @@ repeat: oldprot = pte_pgprot(*kpte); BUG_ON(PageLRU(kpte_page)); BUG_ON(PageCompound(kpte_page)); - ref_prot = canon_pgprot(ref_prot); prot = canon_pgprot(prot); - if (pgprot_val(prot) != pgprot_val(ref_prot)) { - if (level == 4) { - 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 = pte_pgprot(pte_clrhuge(*kpte)); - split = split_large_page(address, ref_prot2); - if (!split) - return -ENOMEM; - pgprot_val(ref_prot2) &= ~_PAGE_NX; - set_pte(kpte, mk_pte(split, ref_prot2)); - goto repeat; - } + if (level == 4) { + set_pte(kpte, pfn_pte(pfn, prot)); } else { - if (level == 4) { - set_pte(kpte, pfn_pte(pfn, ref_prot)); - } else - BUG(); + /* + * split_large_page will take the reference for this + * change_page_attr on the split page. + */ + struct page *split; + + ref_prot2 = pte_pgprot(pte_clrhuge(*kpte)); + split = split_large_page(address, ref_prot2); + if (!split) + return -ENOMEM; + pgprot_val(ref_prot2) &= ~_PAGE_NX; + set_pte(kpte, mk_pte(split, ref_prot2)); + goto repeat; } return 0; @@ -144,8 +135,7 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) unsigned long pfn = __pa(address) >> PAGE_SHIFT; if (!kernel_map || pte_present(pfn_pte(0, prot))) { - err = __change_page_attr(address, pfn, prot, - PAGE_KERNEL); + err = __change_page_attr(address, pfn, prot); if (err) break; } @@ -158,8 +148,7 @@ int change_page_attr_addr(unsigned long address, int numpages, pgprot_t prot) addr2 = __START_KERNEL_map + __pa(address); /* 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); + err = __change_page_attr(addr2, pfn, prot2); } } up_write(&init_mm.mmap_sem); -- 2.20.1