aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/mm/setup_nx.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/mm/setup_nx.c')
-rw-r--r--arch/x86/mm/setup_nx.c59
1 files changed, 25 insertions, 34 deletions
diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c
index 513d8ed5d2e..a3250aa3408 100644
--- a/arch/x86/mm/setup_nx.c
+++ b/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 +20,41 @@ 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)
+void __cpuinit x86_configure_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 (cpu_has_nx && !disable_nx)
+ __supported_pte_mask |= _PAGE_NX;
+ else
+ __supported_pte_mask &= ~_PAGE_NX;
+}
- 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;
+void __init x86_report_nx(void)
+{
+ if (!cpu_has_nx) {
+ printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
+ "missing in CPU or disabled in BIOS!\n");
+ } else {
+#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
+ if (disable_nx) {
+ printk(KERN_INFO "NX (Execute Disable) protection: "
+ "disabled by kernel command line option\n");
+ } else {
+ printk(KERN_INFO "NX (Execute Disable) protection: "
+ "active\n");
}
- }
-}
#else
-void set_nx(void)
-{
-}
+ /* 32bit non-PAE kernel, NX cannot be used */
+ printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
+ "cannot be enabled: non-PAE kernel!\n");
#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
-