[PATCH] x86: Improve handling of kernel mappings in change_page_attr

Fix various broken corner cases in i386 and x86-64 change_page_attr.

AK: split off from tighten kernel image access rights

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index 412ebbd8adb0..ea6b6d4a0a2a 100644
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -142,7 +142,7 @@ __change_page_attr(struct page *page, pgprot_t prot)
                 return -EINVAL;
         kpte_page = virt_to_page(kpte);
         if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) { 
-                if ((pte_val(*kpte) & _PAGE_PSE) == 0) { 
+                if (!pte_huge(*kpte)) {
                         set_pte_atomic(kpte, mk_pte(page, prot)); 
                 } else {
                         pgprot_t ref_prot;
@@ -158,7 +158,7 @@ __change_page_attr(struct page *page, pgprot_t prot)
                         kpte_page = split;
                 }
                 page_private(kpte_page)++;
-        } else if ((pte_val(*kpte) & _PAGE_PSE) == 0) { 
+        } else if (!pte_huge(*kpte)) {
                 set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL));
                 BUG_ON(page_private(kpte_page) == 0);
                 page_private(kpte_page)--;