| Message ID | 20241028160917.1380714-17-alexander.shishkin@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | Enable Linear Address Space Separation support | expand |
"Kirill A. Shutemov" <kirill@shutemov.name> 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@linux.intel.com> >> CC: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> > > 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
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0bdb7a394f59..192d5145f54e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2257,7 +2257,6 @@ config RANDOMIZE_MEMORY_PHYSICAL_PADDING config ADDRESS_MASKING bool "Linear Address Masking support" depends on X86_64 - depends on COMPILE_TEST || !CPU_MITIGATIONS # wait for LASS help Linear Address Masking (LAM) modifies the checking that is applied to 64-bit linear addresses, allowing software to use of the
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@linux.intel.com> CC: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> --- arch/x86/Kconfig | 1 - 1 file changed, 1 deletion(-)