[PATCH 6/7] x86/cpu: Set LASS as pinning sensitive CR4 bit

From: Yian Chen
Date: Tue Jan 10 2023 - 00:58:02 EST


Security protection features are pinning sensitive.
LASS comes with an effort for security concerns.
Therefore, add it to the set of pinning sensitive
bits

Signed-off-by: Yian Chen <yian.chen@xxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
arch/x86/kernel/cpu/common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index efc7c7623968..e224cbaf7866 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -432,7 +432,7 @@ static __always_inline void setup_lass(struct cpuinfo_x86 *c)
/* These bits should not change their value after CPU init is finished. */
static const unsigned long cr4_pinned_mask =
X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_UMIP |
- X86_CR4_FSGSBASE | X86_CR4_CET;
+ X86_CR4_FSGSBASE | X86_CR4_CET | X86_CR4_LASS;
static DEFINE_STATIC_KEY_FALSE_RO(cr_pinning);
static unsigned long cr4_pinned_bits __ro_after_init;

--
2.34.1