Re: [PATCH] Add a text_poke syscall v2

H. Peter Anvin
2013-11-27T22:25:58Z

Actually the CPUID is superfluous on anything than the executing CPU since IRET is serializing.

Borislav Petkov <bp@alien8.de> wrote:
>On Wed, Nov 27, 2013 at 02:02:50PM -0800, H. Peter Anvin wrote:
>> For the record, this is the entire patch necessary to do the
>> sync_cores() system call -- and no potential interactions with
>security
>> frameworks or whatnot, simply because no security-sensitive
>operations
>> are performed of any kind.
>>
>> Comments/opinions appreciated.
>
>And we do this in the kernel not because userspace can't execute
>sync_core() aka CPUID but because for userspace it is hard to IPI all
>cores easily?

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