aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/mm
diff options
context:
space:
mode:
authorJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2009-09-21 16:40:42 -0400
committerJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>2009-09-21 16:56:58 -0400
commitc44c9ec0f38b939b3200436e3aa95c1aa83c41c7 (patch)
tree8a61331dddd6fc5b8d3b1bef1ab7955b96036cba /arch/x86/mm
parentb75fe4e5b869f8dbebd36df64a7fcda0c5b318ed (diff)
x86: split NX setup into separate file to limit unstack-protected code
Move the NX setup into a separate file so that it can be compiled without stack-protection while leaving the rest of the mm/init code protected. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Diffstat (limited to 'arch/x86/mm')
-rw-r--r--arch/x86/mm/Makefile4
-rw-r--r--arch/x86/mm/init.c63
-rw-r--r--arch/x86/mm/setup_nx.c69
3 files changed, 71 insertions, 65 deletions
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index dd313d035de7..06630d26e56d 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -1,10 +1,10 @@
1obj-y := init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \ 1obj-y := init.o init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
2 pat.o pgtable.o physaddr.o gup.o 2 pat.o pgtable.o physaddr.o gup.o setup_nx.o
3 3
4# Make sure __phys_addr has no stackprotector 4# Make sure __phys_addr has no stackprotector
5nostackp := $(call cc-option, -fno-stack-protector) 5nostackp := $(call cc-option, -fno-stack-protector)
6CFLAGS_physaddr.o := $(nostackp) 6CFLAGS_physaddr.o := $(nostackp)
7CFLAGS_init.o := $(nostackp) 7CFLAGS_setup_nx.o := $(nostackp)
8 8
9obj-$(CONFIG_SMP) += tlb.o 9obj-$(CONFIG_SMP) += tlb.o
10 10
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 0607119cef94..73ffd5536f62 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -28,69 +28,6 @@ int direct_gbpages
28#endif 28#endif
29; 29;
30 30
31int nx_enabled;
32
33#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
34static int disable_nx __cpuinitdata;
35
36/*
37 * noexec = on|off
38 *
39 * Control non-executable mappings for processes.
40 *
41 * on Enable
42 * off Disable
43 */
44static int __init noexec_setup(char *str)
45{
46 if (!str)
47 return -EINVAL;
48 if (!strncmp(str, "on", 2)) {
49 __supported_pte_mask |= _PAGE_NX;
50 disable_nx = 0;
51 } else if (!strncmp(str, "off", 3)) {
52 disable_nx = 1;
53 __supported_pte_mask &= ~_PAGE_NX;
54 }
55 return 0;
56}
57early_param("noexec", noexec_setup);
58#endif
59
60#ifdef CONFIG_X86_PAE
61static void __init set_nx(void)
62{
63 unsigned int v[4], l, h;
64
65 if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) {
66 cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]);
67
68 if ((v[3] & (1 << 20)) && !disable_nx) {
69 rdmsr(MSR_EFER, l, h);
70 l |= EFER_NX;
71 wrmsr(MSR_EFER, l, h);
72 nx_enabled = 1;
73 __supported_pte_mask |= _PAGE_NX;
74 }
75 }
76}
77#else
78static inline void set_nx(void)
79{
80}
81#endif
82
83#ifdef CONFIG_X86_64
84void __cpuinit check_efer(void)
85{
86 unsigned long efer;
87
88 rdmsrl(MSR_EFER, efer);
89 if (!(efer & EFER_NX) || disable_nx)
90 __supported_pte_mask &= ~_PAGE_NX;
91}
92#endif
93
94static void __init find_early_table_space(unsigned long end, int use_pse, 31static void __init find_early_table_space(unsigned long end, int use_pse,
95 int use_gbpages) 32 int use_gbpages)
96{ 33{
diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c
new file mode 100644
index 000000000000..513d8ed5d2ec
--- /dev/null
+++ b/arch/x86/mm/setup_nx.c
@@ -0,0 +1,69 @@
1#include <linux/spinlock.h>
2#include <linux/errno.h>
3#include <linux/init.h>
4
5#include <asm/pgtable.h>
6
7int nx_enabled;
8
9#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
10static int disable_nx __cpuinitdata;
11
12/*
13 * noexec = on|off
14 *
15 * Control non-executable mappings for processes.
16 *
17 * on Enable
18 * off Disable
19 */
20static int __init noexec_setup(char *str)
21{
22 if (!str)
23 return -EINVAL;
24 if (!strncmp(str, "on", 2)) {
25 __supported_pte_mask |= _PAGE_NX;
26 disable_nx = 0;
27 } else if (!strncmp(str, "off", 3)) {
28 disable_nx = 1;
29 __supported_pte_mask &= ~_PAGE_NX;
30 }
31 return 0;
32}
33early_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
59#ifdef CONFIG_X86_64
60void __cpuinit check_efer(void)
61{
62 unsigned long efer;
63
64 rdmsrl(MSR_EFER, efer);
65 if (!(efer & EFER_NX) || disable_nx)
66 __supported_pte_mask &= ~_PAGE_NX;
67}
68#endif
69