From 3a19109efbfa7d887996a74257556a46e00525c2 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 17 Sep 2015 12:24:22 -0600 Subject: [PATCH] x86/mm: Fix try_preserve_large_page() to handle large PAT bit try_preserve_large_page() is called from __change_page_attr() to change the mapping attribute of a given large page. This function uses pte_pfn() and pte_pgprot() for PUD/PMD, which do not handle the large PAT bit properly. Fix try_preserve_large_page() by using the corresponding pud/pmd prot/pfn interfaces. Also remove '#ifdef CONFIG_X86_64', which is not necessary. Signed-off-by: Toshi Kani Cc: Andrew Morton Cc: Juergen Gross Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Borislav Petkov Cc: Konrad Wilk Cc: Robert Elliot Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1442514264-12475-10-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner --- arch/x86/mm/pageattr.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 1441368a7931..3f612713159a 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -468,7 +468,7 @@ static int try_preserve_large_page(pte_t *kpte, unsigned long address, struct cpa_data *cpa) { - unsigned long nextpage_addr, numpages, pmask, psize, addr, pfn; + unsigned long nextpage_addr, numpages, pmask, psize, addr, pfn, old_pfn; pte_t new_pte, old_pte, *tmp; pgprot_t old_prot, new_prot, req_prot; int i, do_split = 1; @@ -488,17 +488,21 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, switch (level) { case PG_LEVEL_2M: -#ifdef CONFIG_X86_64 + old_prot = pmd_pgprot(*(pmd_t *)kpte); + old_pfn = pmd_pfn(*(pmd_t *)kpte); + break; case PG_LEVEL_1G: -#endif - psize = page_level_size(level); - pmask = page_level_mask(level); + old_prot = pud_pgprot(*(pud_t *)kpte); + old_pfn = pud_pfn(*(pud_t *)kpte); break; default: do_split = -EINVAL; goto out_unlock; } + psize = page_level_size(level); + pmask = page_level_mask(level); + /* * Calculate the number of pages, which fit into this large * page starting at address: @@ -514,7 +518,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, * up accordingly. */ old_pte = *kpte; - old_prot = req_prot = pgprot_large_2_4k(pte_pgprot(old_pte)); + old_prot = req_prot = pgprot_large_2_4k(old_prot); pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr); pgprot_val(req_prot) |= pgprot_val(cpa->mask_set); @@ -540,10 +544,10 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, req_prot = canon_pgprot(req_prot); /* - * old_pte points to the large page base address. So we need + * old_pfn points to the large page base pfn. So we need * to add the offset of the virtual address: */ - pfn = pte_pfn(old_pte) + ((address & (psize - 1)) >> PAGE_SHIFT); + pfn = old_pfn + ((address & (psize - 1)) >> PAGE_SHIFT); cpa->pfn = pfn; new_prot = static_protections(req_prot, address, pfn); @@ -554,7 +558,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, * the pages in the range we try to preserve: */ addr = address & pmask; - pfn = pte_pfn(old_pte); + pfn = old_pfn; for (i = 0; i < (psize >> PAGE_SHIFT); i++, addr += PAGE_SIZE, pfn++) { pgprot_t chk_prot = static_protections(req_prot, addr, pfn); @@ -584,7 +588,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, * The address is aligned and the number of pages * covers the full page. */ - new_pte = pfn_pte(pte_pfn(old_pte), new_prot); + new_pte = pfn_pte(old_pfn, new_prot); __set_pmd_pte(kpte, address, new_pte); cpa->flags |= CPA_FLUSHTLB; do_split = 0; -- 2.45.2