linux-kernel - [PATCH v5 16/16] Revert "x86/lam: Disable ADDRESS

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Message-ID: <20241028160917.1380714-17-alexander.shishkin@linux.intel.com>
Date: Mon, 28 Oct 2024 18:08:04 +0200
From: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
To: Andy Lutomirski <luto@...nel.org>,
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Subject: [PATCH v5 16/16] Revert "x86/lam: Disable ADDRESS_MASKING in most cases"

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@...ux.intel.com>
CC: Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
---
 arch/x86/Kconfig | 1 -
 1 file changed, 1 deletion(-)

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
-- 
2.45.2