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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-12-09 17:14:38 +1100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-12-09 17:14:38 +1100 |
| commit | bcd6acd51f3d4d1ada201e9bc5c40a31d6d80c71 (patch) | |
| tree | 2f6dffd2d3e4dd67355a224de7e7a960335a92fd /arch/x86/mm/setup_nx.c | |
| parent | 11c34c7deaeeebcee342cbc35e1bb2a6711b2431 (diff) | |
| parent | 3ff6a468b45b5dfeb0e903e56f4eb27d34b2437c (diff) | |
Merge commit 'origin/master' into next
Conflicts:
include/linux/kvm.h
Diffstat (limited to 'arch/x86/mm/setup_nx.c')
| -rw-r--r-- | arch/x86/mm/setup_nx.c | 59 |
1 files changed, 25 insertions, 34 deletions
diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c index 513d8ed5d2e..a3250aa3408 100644 --- a/arch/x86/mm/setup_nx.c +++ b/arch/x86/mm/setup_nx.c @@ -3,10 +3,8 @@ #include <linux/init.h> #include <asm/pgtable.h> +#include <asm/proto.h> -int nx_enabled; - -#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) static int disable_nx __cpuinitdata; /* @@ -22,48 +20,41 @@ static int __init noexec_setup(char *str) if (!str) return -EINVAL; if (!strncmp(str, "on", 2)) { - __supported_pte_mask |= _PAGE_NX; disable_nx = 0; } else if (!strncmp(str, "off", 3)) { disable_nx = 1; - __supported_pte_mask &= ~_PAGE_NX; } + x86_configure_nx(); return 0; } early_param("noexec", noexec_setup); -#endif -#ifdef CONFIG_X86_PAE -void __init set_nx(void) +void __cpuinit x86_configure_nx(void) { - unsigned int v[4], l, h; - - if (cpu_has_pae && (cpuid_eax(0x80000000) > 0x80000001)) { - cpuid(0x80000001, &v[0], &v[1], &v[2], &v[3]); + if (cpu_has_nx && !disable_nx) + __supported_pte_mask |= _PAGE_NX; + else + __supported_pte_mask &= ~_PAGE_NX; +} - if ((v[3] & (1 << 20)) && !disable_nx) { - rdmsr(MSR_EFER, l, h); - l |= EFER_NX; - wrmsr(MSR_EFER, l, h); - nx_enabled = 1; - __supported_pte_mask |= _PAGE_NX; +void __init x86_report_nx(void) +{ + if (!cpu_has_nx) { + printk(KERN_NOTICE "Notice: NX (Execute Disable) protection " + "missing in CPU or disabled in BIOS!\n"); + } else { +#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) + if (disable_nx) { + printk(KERN_INFO "NX (Execute Disable) protection: " + "disabled by kernel command line option\n"); + } else { + printk(KERN_INFO "NX (Execute Disable) protection: " + "active\n"); } - } -} #else -void set_nx(void) -{ -} + /* 32bit non-PAE kernel, NX cannot be used */ + printk(KERN_NOTICE "Notice: NX (Execute Disable) protection " + "cannot be enabled: non-PAE kernel!\n"); #endif - -#ifdef CONFIG_X86_64 -void __cpuinit check_efer(void) -{ - unsigned long efer; - - rdmsrl(MSR_EFER, efer); - if (!(efer & EFER_NX) || disable_nx) - __supported_pte_mask &= ~_PAGE_NX; + } } -#endif - |