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

[Borislav Petkov]

On Mon, Oct 14, 2024 at 04:39:26PM +0100, Andrew Cooper wrote:
> But, I expect it will malfunction on newer hardware when
> CONFIG_X86_5LEVEL=n, because it causes Linux to explicitly ignore the
> LA57 bit.  That can be fixed by changing how CONFIG_X86_5LEVEL works.

https://lore.kernel.org/all/80734605-1926-4ac7-9c63-006fe3ea6b6a@amd.com/

But there was some lmbench regression...

-- 
Regards/Gruss,
    Boris.

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