[PATCH v2 08/11] arm64: Convert CONFIG_ARM64_MTE to FTR_CONFIG()

Marc Zyngier maz at kernel.org
Mon Mar 2 03:56:49 PST 2026


While CONFIG_ARM64_MTE=n prevents userspace from using MTE,
the sanitised ID registers still advertise the feature.

Make it clear that nothing in the kernel should rely on this by
marking the feature as hidden for all when CONFIG_ARM64_MTE=n.

This is functionnaly equivalent to using arm64.nomte on the kernel
command-line.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kernel/cpufeature.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index ab0a7d72608d4..a56d242fe1489 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -315,7 +315,7 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_SME_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_MPAM_frac_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_RAS_frac_SHIFT, 4, 0),
-	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_MTE),
+	ARM64_FTR_BITS(FTR_CONFIG(CONFIG_ARM64_MTE, VISIBLE, ALL_HIDDEN),
 		       FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_MTE_SHIFT, 4, ID_AA64PFR1_EL1_MTE_NI),
 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_EL1_SSBS_SHIFT, 4, ID_AA64PFR1_EL1_SSBS_NI),
 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
-- 
2.47.3




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