Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip:
x86: Disable large pages on CPUs with Atom erratum AAE44
x86-64: Clear a 64-bit FS/GS base on fork if selector is nonzero
x86, mrst: Conditionally register cpu hotplug notifier for apbt
diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c
index ff469e4..a353475 100644
--- a/arch/x86/kernel/apb_timer.c
+++ b/arch/x86/kernel/apb_timer.c
@@ -429,7 +429,7 @@
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 7e1cca1..1366c7c 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -47,6 +47,27 @@
(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 dc9690b..17cb329 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -276,12 +276,12 @@
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);