Re: [PATCH] x86/uaccess: Use pointer masking to limit uaccess speculation

From: Mark Rutland
Date: Tue Sep 01 2020 - 10:56:52 EST


On Tue, Sep 01, 2020 at 04:46:41PM +0200, Christoph Hellwig wrote:
> On Tue, Sep 01, 2020 at 03:02:08PM +0100, Mark Rutland wrote:
> > One thing to consider is whether you need a speculation barrier after
> > set_fs(). Otherwise for code like:
>
> FYI, at least for x86 and powerpc I have a pending series to kill
> set_fs(). I'd love to see someone help with the arm/arm64 side, otherwise
> I'll try to get to it eventually.

Is there anything in particular that's tricky, or do you just want
someone to look generally? From a quick grep arch/arm64/* looks clean, but
I suspect that's misleading.

Thanks,
Mark.