1 files changed, 34 insertions, 17 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 4cf30dee8161..84ba74820ad6 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -534,6 +534,36 @@ out_unlock:
         return 0;
 }
 
+static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr,
+                               int primary)
+{
+        /*
+         * Ignore all non primary paths.
+         */
+        if (!primary)
+                return 0;
+
+        /*
+         * Ignore the NULL PTE for kernel identity mapping, as it is expected
+         * to have holes.
+         * Also set numpages to '1' indicating that we processed cpa req for
+         * one virtual address page and its pfn. TBD: numpages can be set based
+         * on the initial value and the level returned by lookup_address().
+         */
+        if (within(vaddr, PAGE_OFFSET,
+                   PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) {
+                cpa->numpages = 1;
+                cpa->pfn = __pa(vaddr) >> PAGE_SHIFT;
+                return 0;
+        } else {
+                WARN(1, KERN_WARNING "CPA: called for zero pte. "
+                        "vaddr = %lx cpa->vaddr = %lx\n", vaddr,
+                        *cpa->vaddr);
+
+                return -EFAULT;
+        }
+}
+
 static int __change_page_attr(struct cpa_data *cpa, int primary)
 {
         unsigned long address;
@@ -549,19 +579,11 @@ static int __change_page_attr(struct cpa_data *cpa, int primary)
 repeat:
         kpte = lookup_address(address, &level);
         if (!kpte)
-                return 0;
+                return __cpa_process_fault(cpa, address, primary);
 
         old_pte = *kpte;
-        if (!pte_val(old_pte)) {
-                if (!primary)
-                        return 0;
-
-                /*
-                 *  Special error value returned, indicating that the mapping
-                 * did not exist at this address.
-                 */
-                return -EFAULT;
-        }
+        if (!pte_val(old_pte))
+                return __cpa_process_fault(cpa, address, primary);
 
         if (level == PG_LEVEL_4K) {
                 pte_t new_pte;
@@ -659,12 +681,7 @@ static int cpa_process_alias(struct cpa_data *cpa)
                 vaddr = *cpa->vaddr;
 
         if (!(within(vaddr, PAGE_OFFSET,
-                    PAGE_OFFSET + (max_low_pfn_mapped << PAGE_SHIFT))
-#ifdef CONFIG_X86_64
-                || within(vaddr, PAGE_OFFSET + (1UL<<32),
-                    PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))
-#endif
-        )) {
+                    PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)))) {
 
                 alias_cpa = *cpa;
                 temp_cpa_vaddr = (unsigned long) __va(cpa->pfn << PAGE_SHIFT);