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Groups > linux.kernel > #1422289
| From | Nadav Amit <nadav.amit@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] Linux VM workaround for Knights Landing A/D leak |
| Date | 2016-06-14 22:20 +0200 |
| Message-ID | <rK2Yx-1dW-1@gated-at.bofh.it> (permalink) |
| References | <rJYUW-6QY-41@gated-at.bofh.it> <rJZHl-7nr-53@gated-at.bofh.it> <rK0am-7OM-21@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Dave Hansen <dave.hansen@linux.intel.com> wrote:
> On 06/14/2016 09:47 AM, Nadav Amit wrote:
>> Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> wrote:
>>
>>>> From: Andi Kleen <ak@linux.intel.com>
>>>> +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));
>>>> + }
>>>> +}
>
> Shouldn't that barrier be incorporated in the TLB flush code itself and
> not every single caller (like this code is)?
>
> It is insane to require individual TLB flushers to be concerned with the
> barriers.
IMHO it is best to use existing flushing interfaces instead of creating
new ones.
In theory, fix_pte_leak could have used flush_tlb_page. But the problem
is that flush_tlb_page requires the vm_area_struct as an argument, which
ptep_get_and_clear (and others) do not have.
I don’t know which architecture needs the vm_area_struct, since x86 and
some others I looked at (e.g., ARM) only need the mm_struct.
Nadav
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[PATCH] Linux VM workaround for Knights Landing A/D leak Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2016-06-14 18:00 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak kbuild test robot <lkp@intel.com> - 2016-06-14 18:40 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-14 18:50 +0200
RE: [PATCH] Linux VM workaround for Knights Landing A/D leak "Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com> - 2016-06-14 19:00 +0200
[PATCH v2] Linux VM workaround for Knights Landing A/D leak Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2016-06-14 19:10 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Dave Hansen <dave.hansen@linux.intel.com> - 2016-06-14 19:30 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2016-06-14 20:40 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Dave Hansen <dave.hansen@linux.intel.com> - 2016-06-14 21:00 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Borislav Petkov <bp@alien8.de> - 2016-06-14 21:20 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak "H. Peter Anvin" <hpa@zytor.com> - 2016-06-14 22:30 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Borislav Petkov <bp@alien8.de> - 2016-06-14 22:50 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak "H. Peter Anvin" <hpa@zytor.com> - 2016-06-14 23:00 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak "H. Peter Anvin" <hpa@zytor.com> - 2016-06-14 23:10 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Borislav Petkov <bp@alien8.de> - 2016-06-14 23:10 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak "H. Peter Anvin" <hpa@zytor.com> - 2016-06-14 23:20 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Borislav Petkov <bp@alien8.de> - 2016-06-14 20:20 +0200
RE: [PATCH v2] Linux VM workaround for Knights Landing A/D leak "Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com> - 2016-06-15 15:20 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-14 20:40 +0200
RE: [PATCH v2] Linux VM workaround for Knights Landing A/D leak "Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com> - 2016-06-15 15:20 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-15 22:10 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Dave Hansen <dave.hansen@linux.intel.com> - 2016-06-15 22:20 +0200
Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-15 22:30 +0200
[PATCH v3] Linux VM workaround for Knights Landing A/D leak Lukasz Anaczkowski <lukasz.anaczkowski@intel.com> - 2016-06-16 17:20 +0200
Re: [PATCH v3] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-16 18:50 +0200
Re: [PATCH v3] Linux VM workaround for Knights Landing A/D leak Dave Hansen <dave.hansen@linux.intel.com> - 2016-06-16 22:30 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Dave Hansen <dave.hansen@linux.intel.com> - 2016-06-14 19:20 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-14 22:20 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Dave Hansen <dave.hansen@linux.intel.com> - 2016-06-14 23:40 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Andy Lutomirski <luto@amacapital.net> - 2016-06-15 04:30 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-15 04:40 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Andy Lutomirski <luto@amacapital.net> - 2016-06-15 04:40 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-15 04:50 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Andy Lutomirski <luto@amacapital.net> - 2016-06-15 05:10 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Nadav Amit <nadav.amit@gmail.com> - 2016-06-15 05:30 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak kbuild test robot <lkp@intel.com> - 2016-06-14 19:00 +0200
Re: [PATCH] Linux VM workaround for Knights Landing A/D leak Dave Hansen <dave.hansen@linux.intel.com> - 2016-06-14 19:30 +0200
RE: [PATCH] Linux VM workaround for Knights Landing A/D leak "Anaczkowski, Lukasz" <lukasz.anaczkowski@intel.com> - 2016-06-15 15:10 +0200
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