Re: [stable:PATCH v5.4.184 00/22] arm64: Mitigate spectre style branch history side channels

James Morse
2022-03-18T12:16:30Z

Hi Greg,

On 3/17/22 10:00 AM, Greg KH wrote:
> On Wed, Mar 16, 2022 at 11:41:07AM -0400, Sasha Levin wrote:
>> On Tue, Mar 15, 2022 at 06:23:53PM +0000, James Morse wrote:
>>> Hi Greg,
>>>
>>> Here is the state of the current v5.4 backport. Now that the 32bit
>>> code has been merged, it doesn't conflict when KVM's shared 32bit/64bit
>>> code needs to use these constants.
>>>
>>> I've fixed the two issues that were reported against the v5.10 backport.
>>>
>>> I had a go at bringing all the pre-requisites in to add proton-pack.c
>>> to v5.4. Its currently 39 patches:
>>> https://git.gitlab.arm.com/linux-arm/linux-jm.git /bhb/alternative_backport/UNTESTED/v5.4.183
>>> (or for web browsers:
>>> https://gitlab.arm.com/linux-arm/linux-jm/-/commits/bhb/alternative_backport/UNTESTED/v5.4.183/
>>> )
>>
>> I've queued it up.
>
> Thanks for merging these, and James, thanks for the backports! I agree,
> this way is a bit "simpler", but thanks for trying the other way as
> well.

> Does this mean that the 4.19 and older backports will be easier?

It means they'll be based on the versions I posted on before. But: the last review comment that
needs addressing is the A76 ID macros that came in with an errata workaround, but the workaround
wasn't backported. I need to work out how easy that is to do.

Thanks,

James