[PATCH] x86/uaccess: Avoid barrier_nospec() in copy_from_user()

[Borislav Petkov]

On Sun, Oct 20, 2024 at 04:35:21PM -0700, Linus Torvalds wrote:
> So I think this time we push back on the hardware people and tell them
>  it's *THEIR* damn problem, and if they can't even be bothered to say
> yay-or-nay, we just sit tight.

So I was able to get some info: CLAC/STAC in everything Zen4 and older is
serializing so there's no issue there.

Zen5 is a different story and AC is being renamed there and thus,
non-serializing. So we'd need to do something there, perhaps something
like Josh's patch...

But the good thing is we can alternative it out only for those machines, apart
from the rest.

Thx.

-- 
Regards/Gruss,
    Boris.

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