From 7f55236a565b54efa09c6f2484206724ad5ce6a9 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Fri, 13 Nov 2009 15:28:16 -0800
Subject: [PATCH] --- yaml --- r: 173049 b: refs/heads/master c:
 4763ed4d45522b876c97e1f7f4b659d211f75571 h: refs/heads/master i:   173047:
 7be4fa90ae40b3a23cc9a24dc6ca4da5cad67078 v: v3

---
 [refs]                             |  2 +-
 trunk/arch/x86/include/asm/proto.h |  2 +-
 trunk/arch/x86/kernel/cpu/common.c |  2 +-
 trunk/arch/x86/kernel/setup.c      |  8 ++----
 trunk/arch/x86/mm/init.c           |  4 +--
 trunk/arch/x86/mm/setup_nx.c       | 43 +++++-------------------------
 trunk/arch/x86/xen/enlighten.c     |  4 +--
 7 files changed, 14 insertions(+), 51 deletions(-)

diff --git a/[refs] b/[refs]
index 81c284c8e845..dad8ac572eca 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 583140afb989f24d115e80be5c91e503b58ccfc0
+refs/heads/master: 4763ed4d45522b876c97e1f7f4b659d211f75571
diff --git a/trunk/arch/x86/include/asm/proto.h b/trunk/arch/x86/include/asm/proto.h
index 621f56d73121..add7f18f17a7 100644
--- a/trunk/arch/x86/include/asm/proto.h
+++ b/trunk/arch/x86/include/asm/proto.h
@@ -16,7 +16,7 @@ extern void ia32_sysenter_target(void);
 
 extern void syscall32_cpu_init(void);
 
-extern void check_efer(void);
+extern void x86_configure_nx(void);
 
 extern int reboot_force;
 
diff --git a/trunk/arch/x86/kernel/cpu/common.c b/trunk/arch/x86/kernel/cpu/common.c
index cc25c2b4a567..18346da8c594 100644
--- a/trunk/arch/x86/kernel/cpu/common.c
+++ b/trunk/arch/x86/kernel/cpu/common.c
@@ -1136,7 +1136,7 @@ void __cpuinit cpu_init(void)
 	wrmsrl(MSR_KERNEL_GS_BASE, 0);
 	barrier();
 
-	check_efer();
+	x86_configure_nx();
 	if (cpu != 0)
 		enable_x2apic();
 
diff --git a/trunk/arch/x86/kernel/setup.c b/trunk/arch/x86/kernel/setup.c
index 0a6e94ab8339..23b7f46bf843 100644
--- a/trunk/arch/x86/kernel/setup.c
+++ b/trunk/arch/x86/kernel/setup.c
@@ -787,21 +787,17 @@ void __init setup_arch(char **cmdline_p)
 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = command_line;
 
-#ifdef CONFIG_X86_64
 	/*
 	 * Must call this twice: Once just to detect whether hardware doesn't
 	 * support NX (so that the early EHCI debug console setup can safely
 	 * call set_fixmap(), and then again after parsing early parameters to
 	 * honor the respective command line option.
 	 */
-	check_efer();
-#endif
+	x86_configure_nx();
 
 	parse_early_param();
 
-#ifdef CONFIG_X86_64
-	check_efer();
-#endif
+	x86_configure_nx();
 
 	/* Must be before kernel pagetables are setup */
 	vmi_activate();
diff --git a/trunk/arch/x86/mm/init.c b/trunk/arch/x86/mm/init.c
index 73ffd5536f62..27ec2c23fd47 100644
--- a/trunk/arch/x86/mm/init.c
+++ b/trunk/arch/x86/mm/init.c
@@ -146,8 +146,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 	use_gbpages = direct_gbpages;
 #endif
 
-	set_nx();
-	if (nx_enabled)
+	/* XXX: replace this with Kees' improved messages */
+	if (__supported_pte_mask & _PAGE_NX)
 		printk(KERN_INFO "NX (Execute Disable) protection: active\n");
 
 	/* Enable PSE if available */
diff --git a/trunk/arch/x86/mm/setup_nx.c b/trunk/arch/x86/mm/setup_nx.c
index 513d8ed5d2ec..355818b087b5 100644
--- a/trunk/arch/x86/mm/setup_nx.c
+++ b/trunk/arch/x86/mm/setup_nx.c
@@ -3,10 +3,8 @@
 #include <linux/init.h>
 
 #include <asm/pgtable.h>
+#include <asm/proto.h>
 
-int nx_enabled;
-
-#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
 static int disable_nx __cpuinitdata;
 
 /*
@@ -22,48 +20,19 @@ 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;
 	}
+	x86_configure_nx();
 	return 0;
 }
 early_param("noexec", noexec_setup);
-#endif
-
-#ifdef CONFIG_X86_PAE
-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
-void set_nx(void)
-{
-}
-#endif
 
-#ifdef CONFIG_X86_64
-void __cpuinit check_efer(void)
+void __cpuinit x86_configure_nx(void)
 {
-	unsigned long efer;
-
-	rdmsrl(MSR_EFER, efer);
-	if (!(efer & EFER_NX) || disable_nx)
+	if (cpu_has_nx && !disable_nx)
+		__supported_pte_mask |= _PAGE_NX;
+	else
 		__supported_pte_mask &= ~_PAGE_NX;
 }
-#endif
-
diff --git a/trunk/arch/x86/xen/enlighten.c b/trunk/arch/x86/xen/enlighten.c
index 3439616d69f1..c5e805d4a788 100644
--- a/trunk/arch/x86/xen/enlighten.c
+++ b/trunk/arch/x86/xen/enlighten.c
@@ -1082,10 +1082,8 @@ asmlinkage void __init xen_start_kernel(void)
 
 	__supported_pte_mask |= _PAGE_IOMAP;
 
-#ifdef CONFIG_X86_64
 	/* Work out if we support NX */
-	check_efer();
-#endif
+	x86_configure_nx();
 
 	xen_setup_features();