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-rw-r--r--arch/x86/mm/init.c78
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;
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