On 2018-09-12 08:49:01 [-0700], Andy Lutomirski wrote:
> Sure, but the first write is *before* this. So we can be preempted with the
> two copies of PKRU being out of sync.
so it took a while to understand this but now that I did, I will
consider this in the next version. Thank you.
Sebastian
> On Sep 12, 2018, at 8:30 AM, Rik van Riel wrote:
>
> On Wed, 2018-09-12 at 08:20 -0700, Andy Lutomirski wrote:
>>>
>>> --- a/arch/x86/mm/pkeys.c
>>> +++ b/arch/x86/mm/pkeys.c
>>> @@ -18,6 +18,20 @@
>>>
>>> #include /* boot_cpu_has,
>>> ...*/
>>> #include
On 12/09/2018 17:24, Andy Lutomirski wrote:
>> I think you can go a step further and exclude PKRU state from
>> copy_kernel_to_fpregs altogether; you just use RDPKRU/WRPKRU. This also
>> means you don't need to call __fpregs_* functions in write_pkru.
>>
>>
> Except that the signal ABI has PKRU in
On Wed, 2018-09-12 at 08:20 -0700, Andy Lutomirski wrote:
> >
> > --- a/arch/x86/mm/pkeys.c
> > +++ b/arch/x86/mm/pkeys.c
> > @@ -18,6 +18,20 @@
> >
> > #include /* boot_cpu_has,
> > ...*/
> > #include /*
> > vma_pkey() */
> > +#include
> >
> On Sep 12, 2018, at 7:18 AM, Paolo Bonzini wrote:
>
>> On 12/09/2018 15:33, Sebastian Andrzej Siewior wrote:
>> From: Rik van Riel
>>
>> While most of a task's FPU state is only needed in user space,
>> the protection keys need to be in place immediately after a
>> context switch.
>>
>>
> On Sep 12, 2018, at 6:33 AM, Sebastian Andrzej Siewior
> wrote:
>
> From: Rik van Riel
>
> While most of a task's FPU state is only needed in user space,
> the protection keys need to be in place immediately after a
> context switch.
>
> The reason is that any accesses to userspace memor
On 12/09/2018 15:33, Sebastian Andrzej Siewior wrote:
> From: Rik van Riel
>
> While most of a task's FPU state is only needed in user space,
> the protection keys need to be in place immediately after a
> context switch.
>
> The reason is that any accesses to userspace memory while running
> in
From: Rik van Riel
While most of a task's FPU state is only needed in user space,
the protection keys need to be in place immediately after a
context switch.
The reason is that any accesses to userspace memory while running
in kernel mode also need to abide by the memory permissions
specified in
8 matches
Mail list logo