summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/cpu/common.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
-rw-r--r--arch/x86/kernel/cpu/common.c33
1 files changed, 27 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4b68bda3093..c8b41623377 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -254,6 +254,25 @@ static inline void squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
}
#endif
+static int disable_smep __cpuinitdata;
+static __init int setup_disable_smep(char *arg)
+{
+ disable_smep = 1;
+ return 1;
+}
+__setup("nosmep", setup_disable_smep);
+
+static __cpuinit void setup_smep(struct cpuinfo_x86 *c)
+{
+ if (cpu_has(c, X86_FEATURE_SMEP)) {
+ if (unlikely(disable_smep)) {
+ setup_clear_cpu_cap(X86_FEATURE_SMEP);
+ clear_in_cr4(X86_CR4_SMEP);
+ } else
+ set_in_cr4(X86_CR4_SMEP);
+ }
+}
+
/*
* Some CPU features depend on higher CPUID levels, which may not always
* be available due to CPUID level capping or broken virtualization
@@ -565,8 +584,7 @@ void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c)
cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
- if (eax > 0)
- c->x86_capability[9] = ebx;
+ c->x86_capability[9] = ebx;
}
/* AMD-defined flags: level 0x80000001 */
@@ -668,6 +686,8 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
c->cpu_index = 0;
#endif
filter_cpuid_features(c, false);
+
+ setup_smep(c);
}
void __init early_cpu_init(void)
@@ -675,7 +695,7 @@ void __init early_cpu_init(void)
const struct cpu_dev *const *cdev;
int count = 0;
-#ifdef PROCESSOR_SELECT
+#ifdef CONFIG_PROCESSOR_SELECT
printk(KERN_INFO "KERNEL supported cpus:\n");
#endif
@@ -687,7 +707,7 @@ void __init early_cpu_init(void)
cpu_devs[count] = cpudev;
count++;
-#ifdef PROCESSOR_SELECT
+#ifdef CONFIG_PROCESSOR_SELECT
{
unsigned int j;
@@ -753,6 +773,8 @@ static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
#endif
}
+ setup_smep(c);
+
get_model_name(c); /* Default name */
detect_nopl(c);
@@ -869,7 +891,7 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
select_idle_routine(c);
-#if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
+#ifdef CONFIG_NUMA
numa_add_cpu(smp_processor_id());
#endif
}
@@ -894,7 +916,6 @@ void __init identify_boot_cpu(void)
#else
vgetcpu_set_mode();
#endif
- init_hw_perf_events();
}
void __cpuinit identify_secondary_cpu(struct cpuinfo_x86 *c)