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Diffstat (limited to 'arch/x86/mm/setup_nx.c')
-rw-r--r--arch/x86/mm/setup_nx.c43
1 files changed, 6 insertions, 37 deletions
diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c
index 513d8ed5d2ec..355818b087b5 100644
--- a/arch/x86/mm/setup_nx.c
+++ b/arch/x86/mm/setup_nx.c
@@ -3,10 +3,8 @@
3#include <linux/init.h> 3#include <linux/init.h>
4 4
5#include <asm/pgtable.h> 5#include <asm/pgtable.h>
6#include <asm/proto.h>
6 7
7int nx_enabled;
8
9#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
10static int disable_nx __cpuinitdata; 8static int disable_nx __cpuinitdata;
11 9
12/* 10/*
@@ -22,48 +20,19 @@ static int __init noexec_setup(char *str)
22 if (!str) 20 if (!str)
23 return -EINVAL; 21 return -EINVAL;
24 if (!strncmp(str, "on", 2)) { 22 if (!strncmp(str, "on", 2)) {
25 __supported_pte_mask |= _PAGE_NX;
26 disable_nx = 0; 23 disable_nx = 0;
27 } else if (!strncmp(str, "off", 3)) { 24 } else if (!strncmp(str, "off", 3)) {
28 disable_nx = 1; 25 disable_nx = 1;
29 __supported_pte_mask &= ~_PAGE_NX;
30 } 26 }
27 x86_configure_nx();
31 return 0; 28 return 0;
32} 29}
33early_param("noexec", noexec_setup); 30early_param("noexec", noexec_setup);
34#endif
35
36#ifdef CONFIG_X86_PAE
37void __init set_nx(void)
38{
39 unsigned int v[4], l, h;
40
41 if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
42 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
43
44 if ((v[3] & (1 << 20)) && !disable_nx) {
45 rdmsr(MSR_EFER, l, h);
46 l |= EFER_NX;
47 wrmsr(MSR_EFER, l, h);
48 nx_enabled = 1;
49 __supported_pte_mask |= _PAGE_NX;
50 }
51 }
52}
53#else
54void set_nx(void)
55{
56}
57#endif
58 31
59#ifdef CONFIG_X86_64 32void __cpuinit x86_configure_nx(void)
60void __cpuinit check_efer(void)
61{ 33{
62 unsigned long efer; 34 if (cpu_has_nx && !disable_nx)
63 35 __supported_pte_mask |= _PAGE_NX;
64 rdmsrl(MSR_EFER, efer); 36 else
65 if (!(efer & EFER_NX) || disable_nx)
66 __supported_pte_mask &= ~_PAGE_NX; 37 __supported_pte_mask &= ~_PAGE_NX;
67} 38}
68#endif
69