1 files changed, 70 insertions, 8 deletions

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index ae4f7b5d7104..34c1bfb64f1c 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -1,3 +1,4 @@
+#include <linux/initrd.h>
 #include <linux/ioport.h>
 #include <linux/swap.h>
 
@@ -10,6 +11,9 @@
 #include <asm/setup.h>
 #include <asm/system.h>
 #include <asm/tlbflush.h>
+#include <asm/tlb.h>
+
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 
 unsigned long __initdata e820_table_start;
 unsigned long __meminitdata e820_table_end;
@@ -23,6 +27,69 @@ int direct_gbpages
 #endif
 ;
 
+int nx_enabled;
+
+#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
+static int disable_nx __cpuinitdata;
+
+/*
+ * noexec = on|off
+ *
+ * Control non-executable mappings for processes.
+ *
+ * on      Enable
+ * off     Disable
+ */
+static int __init noexec_setup(char *str)
+{
+        if (!str)
+                return -EINVAL;
+        if (!strncmp(str, "on", 2)) {
+                __supported_pte_mask |= _PAGE_NX;
+                disable_nx = 0;
+        } else if (!strncmp(str, "off", 3)) {
+                disable_nx = 1;
+                __supported_pte_mask &= ~_PAGE_NX;
+        }
+        return 0;
+}
+early_param("noexec", noexec_setup);
+#endif
+
+#ifdef CONFIG_X86_PAE
+static void __init set_nx(void)
+{
+        unsigned int v[4], l, h;
+
+        if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
+                cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
+
+                if ((v[3] & (1 << 20)) && !disable_nx) {
+                        rdmsr(MSR_EFER, l, h);
+                        l |= EFER_NX;
+                        wrmsr(MSR_EFER, l, h);
+                        nx_enabled = 1;
+                        __supported_pte_mask |= _PAGE_NX;
+                }
+        }
+}
+#else
+static inline void set_nx(void)
+{
+}
+#endif
+
+#ifdef CONFIG_X86_64
+void __cpuinit check_efer(void)
+{
+        unsigned long efer;
+
+        rdmsrl(MSR_EFER, efer);
+        if (!(efer & EFER_NX) || disable_nx)
+                __supported_pte_mask &= ~_PAGE_NX;
+}
+#endif
+
 static void __init find_early_table_space(unsigned long end, int use_pse,
                                           int use_gbpages)
 {
@@ -66,12 +133,11 @@ static void __init find_early_table_space(unsigned long end, int use_pse,
          */
 #ifdef CONFIG_X86_32
         start = 0x7000;
-        e820_table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
-                                        tables, PAGE_SIZE);
-#else /* CONFIG_X86_64 */
+#else
         start = 0x8000;
-        e820_table_start = find_e820_area(start, end, tables, PAGE_SIZE);
 #endif
+        e820_table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
+                                        tables, PAGE_SIZE);
         if (e820_table_start == -1UL)
                 panic("Cannot find space for the kernel page tables");
 
@@ -159,12 +225,9 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
         use_gbpages = direct_gbpages;
 #endif
 
-#ifdef CONFIG_X86_32
-#ifdef CONFIG_X86_PAE
         set_nx();
         if (nx_enabled)
                 printk(KERN_INFO "NX (Execute Disable) protection: active\n");
-#endif
 
         /* Enable PSE if available */
         if (cpu_has_pse)
@@ -175,7 +238,6 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
                 set_in_cr4(X86_CR4_PGE);
                 __supported_pte_mask |= _PAGE_GLOBAL;
         }
-#endif
 
         if (use_gbpages)
                 page_size_mask |= 1 << PG_LEVEL_1G;