On Mon, Nov 27, 2017 at 11:49:09AM +0100, Ingo Molnar wrote: > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 7b348cc33e2d..f4f4ab8525bd 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1515,7 +1515,7 @@ EXPORT_PER_CPU_SYMBOL(__preempt_count); > * the top of the kernel stack. Use an extra percpu variable to track the > * top of the kernel stack directly. > */ > -DEFINE_PER_CPU(unsigned long, cpu_current_top_of_stack) = > +DEFINE_PER_CPU_USER_MAPPED(unsigned long, cpu_current_top_of_stack) = > (unsigned long)&init_thread_union + THREAD_SIZE; > EXPORT_PER_CPU_SYMBOL(cpu_current_top_of_stack);
I can't find where we would access this one without already having switched to kernel CR3. A kernel with this entire patch reverted seems to boot for me.
