Re: [PATCH v5 16/16] Revert "x86/lam: Disable ADDRESS_MASKING in most cases"

[Alexander Shishkin]

"Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> writes:

> On Mon, Oct 28, 2024 at 06:08:04PM +0200, Alexander Shishkin wrote:
>> This reverts commit 3267cb6d3a174ff83d6287dcd5b0047bbd912452.
>> 
>> LASS mitigates the Spectre based on LAM (SLAM) [1] and an earlier
>> commit made LAM depend on LASS, so we no longer need to disable LAM at
>> compile time, so revert the commit that disables LAM.
>> 
>> [1] https://download.vusec.net/papers/slam_sp24.pdf
>> 
>> Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
>> CC: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
>
> Before re-enabling LAM, you need to uncomment X86_FEATURE_LAM check in
> arch/x86/kernel/cpu/common.c introduced in recent 86e6b1547b3d ("x86: fix
> user address masking non-canonical speculation issue").

Forgot about that one. Thanks!

Regards,
--
Alex