Re: [PATCH] Linux VM workaround for Knights Landing A/D leak

From: Nadav Amit
Date: Tue Jun 14 2016 - 12:47:49 EST



Lukasz Anaczkowski <lukasz.anaczkowski@xxxxxxxxx> wrote:

> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> +void fix_pte_leak(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
> +{
Here there should be a call to smp_mb__after_atomic() to synchronize with
switch_mm. I submitted a similar patch, which is still pending (hint).

> + if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids) {
> + trace_tlb_flush(TLB_LOCAL_SHOOTDOWN, TLB_FLUSH_ALL);
> + flush_tlb_others(mm_cpumask(mm), mm, addr,
> + addr + PAGE_SIZE);
> + mb();
> + set_pte(ptep, __pte(0));
> + }
> +}

Regards,
Nadav