x86: fix some bugs about EFI runtime code mapping

This patch fixes some bugs of making EFI runtime code executable.

- Use change_page_attr in i386 too. Because the runtime code may be
  mapped not through ioremap.

- If there is no _PAGE_NX in __supported_pte_mask, the change_page_attr
  is not called.

- Make efi_ioremap map pages as PAGE_KERNEL_EXEC_NOCACHE, because EFI runtime
  code may be mapped through efi_ioremap.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 30 insertions, 5 deletions

diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c
index 5d492f99d967..834ecfb41e97 100644
--- a/arch/x86/kernel/efi.c
+++ b/arch/x86/kernel/efi.c
@@ -40,6 +40,8 @@
 #include <asm/setup.h>
 #include <asm/efi.h>
 #include <asm/time.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
 
 #define EFI_DEBUG       1
 #define PFX             "EFI: "
@@ -379,6 +381,32 @@ void __init efi_init(void)
 #endif
 }
 
+#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
+static void __init runtime_code_page_mkexec(void)
+{
+        efi_memory_desc_t *md;
+        unsigned long end;
+        void *p;
+
+        if (!(__supported_pte_mask & _PAGE_NX))
+                return;
+
+        /* Make EFI runtime service code area executable */
+        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+                md = p;
+                end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
+                if (md->type == EFI_RUNTIME_SERVICES_CODE &&
+                    (end >> PAGE_SHIFT) <= end_pfn_map)
+                        change_page_attr_addr(md->virt_addr,
+                                              md->num_pages,
+                                              PAGE_KERNEL_EXEC_NOCACHE);
+        }
+        __flush_tlb_all();
+}
+#else
+static inline void __init runtime_code_page_mkexec(void) { }
+#endif
+
 /*
  * This function will switch the EFI runtime services to virtual mode.
  * Essentially, look through the EFI memmap and map every region that
@@ -399,9 +427,9 @@ void __init efi_enter_virtual_mode(void)
                 md = p;
                 if (!(md->attribute & EFI_MEMORY_RUNTIME))
                         continue;
+                end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
                 if ((md->attribute & EFI_MEMORY_WB) &&
-                    (((md->phys_addr + (md->num_pages<<EFI_PAGE_SHIFT)) >>
-                      PAGE_SHIFT) < end_pfn_map))
+                    ((end >> PAGE_SHIFT) <= end_pfn_map))
                         md->virt_addr = (unsigned long)__va(md->phys_addr);
                 else
                         md->virt_addr = (unsigned long)
@@ -410,7 +438,6 @@ void __init efi_enter_virtual_mode(void)
                 if (!md->virt_addr)
                         printk(KERN_ERR PFX "ioremap of 0x%llX failed!\n",
                                (unsigned long long)md->phys_addr);
-                end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
                 if ((md->phys_addr <= (unsigned long)efi_phys.systab) &&
                     ((unsigned long)efi_phys.systab < end))
                         efi.systab = (efi_system_table_t *)(unsigned long)
@@ -448,9 +475,7 @@ void __init efi_enter_virtual_mode(void)
         efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
         efi.reset_system = virt_efi_reset_system;
         efi.set_virtual_address_map = virt_efi_set_virtual_address_map;
-#ifdef CONFIG_X86_64
         runtime_code_page_mkexec();
-#endif
 }
 
 /*