projects / deliverable / linux.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> | |
| 6 | ||
| 7 | int nx_enabled; | |
| 8 | ||
| 9 | #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) | |
| 10 | static 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 | */ | |
| 20 | static 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 | } | |
| 33 | early_param("noexec", noexec_setup); | |
| 34 | #endif | |
| 35 | ||
| 36 | #ifdef CONFIG_X86_PAE | |
| 37 | void __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 | |
| 54 | void set_nx(void) | |
| 55 | { | |
| 56 | } | |
| 57 | #endif | |
| 58 | ||
| 59 | #ifdef CONFIG_X86_64 | |
| 60 | void __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 |