1 files changed, 30 insertions, 26 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 532a40bc0e7e..ec07c1873d65 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -305,49 +305,53 @@ repeat:
  * Modules and drivers should use the set_memory_* APIs instead.
  */
 
+#define HIGH_MAP_START  __START_KERNEL_map
+#define HIGH_MAP_END    (__START_KERNEL_map + KERNEL_TEXT_SIZE)
+
 static int
 change_page_attr_addr(unsigned long address, pgprot_t mask_set,
-                                                        pgprot_t mask_clr)
+                      pgprot_t mask_clr)
 {
-        int err = 0, kernel_map = 0;
-        unsigned long pfn;
+        unsigned long phys_addr = __pa(address);
+        unsigned long pfn = phys_addr >> PAGE_SHIFT;
+        int err;
 
 #ifdef CONFIG_X86_64
-        if (address >= __START_KERNEL_map &&
-                        address < __START_KERNEL_map + KERNEL_TEXT_SIZE) {
-
-                address = (unsigned long)__va(__pa((void *)address));
-                kernel_map = 1;
-        }
+        /*
+         * If we are inside the high mapped kernel range, then we
+         * fixup the low mapping first. __va() returns the virtual
+         * address in the linear mapping:
+         */
+        if (within(address, HIGH_MAP_START, HIGH_MAP_END))
+                address = (unsigned long) __va(phys_addr);
 #endif
 
-        pfn = __pa(address) >> PAGE_SHIFT;
-
-        if (!kernel_map || 1) {
-                err = __change_page_attr(address, pfn, mask_set, mask_clr);
-                if (err)
-                        return err;
-        }
+        err = __change_page_attr(address, pfn, mask_set, mask_clr);
+        if (err)
+                return err;
 
 #ifdef CONFIG_X86_64
         /*
-         * Handle kernel mapping too which aliases part of
-         * lowmem:
+         * If the physical address is inside the kernel map, we need
+         * to touch the high mapped kernel as well:
          */
-        if (__pa(address) < KERNEL_TEXT_SIZE) {
-                unsigned long addr2;
-
-                addr2 = __pa(address) + __START_KERNEL_map - phys_base;
+        if (within(phys_addr, 0, KERNEL_TEXT_SIZE)) {
+                /*
+                 * Calc the high mapping address. See __phys_addr()
+                 * for the non obvious details.
+                 */
+                address = phys_addr + HIGH_MAP_START - phys_base;
                 /* Make sure the kernel mappings stay executable */
                 pgprot_val(mask_clr) |= _PAGE_NX;
+
                 /*
-                 * Our high aliases are imprecise, so do not propagate
-                 * failures back to users:
+                 * Our high aliases are imprecise, because we check
+                 * everything between 0 and KERNEL_TEXT_SIZE, so do
+                 * not propagate lookup failures back to users:
                  */
-                __change_page_attr(addr2, pfn, mask_set, mask_clr);
+                __change_page_attr(address, pfn, mask_set, mask_clr);
         }
 #endif
-
         return err;
 }