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