diff options
| -rw-r--r-- | arch/x86/kernel/apb_timer.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 21 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 4 |
3 files changed, 24 insertions, 3 deletions
diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c index ff469e47005..a35347501d3 100644 --- a/arch/x86/kernel/apb_timer.c +++ b/arch/x86/kernel/apb_timer.c @@ -429,7 +429,7 @@ static int apbt_cpuhp_notify(struct notifier_block *n, static __init int apbt_late_init(void) { - if (disable_apbt_percpu) + if (disable_apbt_percpu || !apb_timer_block_enabled) return 0; /* This notifier should be called after workqueue is ready */ hotcpu_notifier(apbt_cpuhp_notify, -20); diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 7e1cca13af3..1366c7cfd48 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -47,6 +47,27 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); + /* + * Atom erratum AAE44/AAF40/AAG38/AAH41: + * + * A race condition between speculative fetches and invalidating + * a large page. This is worked around in microcode, but we + * need the microcode to have already been loaded... so if it is + * not, recommend a BIOS update and disable large pages. + */ + if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2) { + u32 ucode, junk; + + wrmsr(MSR_IA32_UCODE_REV, 0, 0); + sync_core(); + rdmsr(MSR_IA32_UCODE_REV, junk, ucode); + + if (ucode < 0x20e) { + printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n"); + clear_cpu_cap(c, X86_FEATURE_PSE); + } + } + #ifdef CONFIG_X86_64 set_cpu_cap(c, X86_FEATURE_SYSENTER32); #else diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index dc9690b4c4c..17cb3295cbf 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -276,12 +276,12 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, set_tsk_thread_flag(p, TIF_FORK); - p->thread.fs = me->thread.fs; - p->thread.gs = me->thread.gs; p->thread.io_bitmap_ptr = NULL; savesegment(gs, p->thread.gsindex); + p->thread.gs = p->thread.gsindex ? 0 : me->thread.gs; savesegment(fs, p->thread.fsindex); + p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs; savesegment(es, p->thread.es); savesegment(ds, p->thread.ds); |