Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
c44c9ec0 JF |
2 | #include <linux/spinlock.h> |
3 | #include <linux/errno.h> | |
4 | #include <linux/init.h> | |
5 | ||
6 | #include <asm/pgtable.h> | |
4763ed4d | 7 | #include <asm/proto.h> |
cd4d09ec | 8 | #include <asm/cpufeature.h> |
c44c9ec0 | 9 | |
148f9bb8 | 10 | static int disable_nx; |
c44c9ec0 JF |
11 | |
12 | /* | |
13 | * noexec = on|off | |
14 | * | |
15 | * Control non-executable mappings for processes. | |
16 | * | |
17 | * on Enable | |
18 | * off Disable | |
19 | */ | |
20 | static int __init noexec_setup(char *str) | |
21 | { | |
22 | if (!str) | |
23 | return -EINVAL; | |
24 | if (!strncmp(str, "on", 2)) { | |
c44c9ec0 JF |
25 | disable_nx = 0; |
26 | } else if (!strncmp(str, "off", 3)) { | |
27 | disable_nx = 1; | |
c44c9ec0 | 28 | } |
4763ed4d | 29 | x86_configure_nx(); |
c44c9ec0 JF |
30 | return 0; |
31 | } | |
32 | early_param("noexec", noexec_setup); | |
c44c9ec0 | 33 | |
148f9bb8 | 34 | void x86_configure_nx(void) |
c44c9ec0 | 35 | { |
e16d8a6c AL |
36 | if (boot_cpu_has(X86_FEATURE_NX) && !disable_nx) |
37 | __supported_pte_mask |= _PAGE_NX; | |
38 | else | |
c44c9ec0 JF |
39 | __supported_pte_mask &= ~_PAGE_NX; |
40 | } | |
4b0f3b81 KC |
41 | |
42 | void __init x86_report_nx(void) | |
43 | { | |
362f924b | 44 | if (!boot_cpu_has(X86_FEATURE_NX)) { |
4b0f3b81 | 45 | printk(KERN_NOTICE "Notice: NX (Execute Disable) protection " |
6036f373 | 46 | "missing in CPU!\n"); |
4b0f3b81 KC |
47 | } else { |
48 | #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) | |
49 | if (disable_nx) { | |
50 | printk(KERN_INFO "NX (Execute Disable) protection: " | |
51 | "disabled by kernel command line option\n"); | |
52 | } else { | |
53 | printk(KERN_INFO "NX (Execute Disable) protection: " | |
54 | "active\n"); | |
55 | } | |
56 | #else | |
57 | /* 32bit non-PAE kernel, NX cannot be used */ | |
58 | printk(KERN_NOTICE "Notice: NX (Execute Disable) protection " | |
59 | "cannot be enabled: non-PAE kernel!\n"); | |
60 | #endif | |
61 | } | |
62 | } |