x86: unify noexec handling

This patch unifies noexec handling on 32-bit and 64-bit.

[ Impact: cleanup ]

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[ mingo@elte.hu: build fix ]
LKML-Reference: <1240303167.771.69.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

4 files changed, 63 insertions, 90 deletions

diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index b8238dc8786d..4d258ad76a0f 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -273,7 +273,6 @@ typedef struct page *pgtable_t;
 
 extern pteval_t __supported_pte_mask;
 extern int nx_enabled;
-extern void set_nx(void);
 
 #define pgprot_writecombine     pgprot_writecombine
 extern pgprot_t pgprot_writecombine(pgprot_t prot);
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index fd3da1dda1c9..fedde5359a04 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -22,6 +22,69 @@ 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)
 {
@@ -158,12 +221,9 @@ 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)
@@ -174,7 +234,6 @@ 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;
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 749559ed80f5..2b27120665b3 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -587,61 +587,9 @@ void zap_low_mappings(void)
         flush_tlb_all();
 }
 
-int nx_enabled;
-
 pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL | _PAGE_IOMAP);
 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 
-#ifdef CONFIG_X86_PAE
-
-static int disable_nx __initdata;
-
-/*
- * noexec = on|off
- *
- * Control non executable mappings.
- *
- * on      Enable
- * off     Disable
- */
-static int __init noexec_setup(char *str)
-{
-        if (!str || !strcmp(str, "on")) {
-                if (cpu_has_nx) {
-                        __supported_pte_mask |= _PAGE_NX;
-                        disable_nx = 0;
-                }
-        } else {
-                if (!strcmp(str, "off")) {
-                        disable_nx = 1;
-                        __supported_pte_mask &= ~_PAGE_NX;
-                } else {
-                        return -EINVAL;
-                }
-        }
-
-        return 0;
-}
-early_param("noexec", noexec_setup);
-
-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;
-                }
-        }
-}
-#endif
-
 /* user-defined highmem size */
 static unsigned int highmem_pages = -1;
 
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 1753e8020df6..a4e7846efb1a 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -85,39 +85,6 @@ early_param("gbpages", parse_direct_gbpages_on);
 pteval_t __supported_pte_mask __read_mostly = ~_PAGE_IOMAP;
 EXPORT_SYMBOL_GPL(__supported_pte_mask);
 
-static int disable_nx __cpuinitdata;
-
-/*
- * noexec=on|off
- * Control non-executable mappings for 64-bit processes.
- *
- * on   Enable (default)
- * off  Disable
- */
-static int __init nonx_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", nonx_setup);
-
-void __cpuinit check_efer(void)
-{
-        unsigned long efer;
-
-        rdmsrl(MSR_EFER, efer);
-        if (!(efer & EFER_NX) || disable_nx)
-                __supported_pte_mask &= ~_PAGE_NX;
-}
-
 int force_personality32;
 
 /*