Hook up an override for GCS, allowing it to be disabled from the command
line by specifying arm64.nogcs in case there are problems.
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 6 ++++++
arch/arm64/kernel/idreg-override.c | 2 ++
2 files changed, 8 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 0a1731a0f0ef..7afea5f41ce0 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -418,9 +418,15 @@
arm64.nobti [ARM64] Unconditionally disable Branch Target
Identification support
+ arm64.nogcs [ARM64] Unconditionally disable Guarded Control Stack
+ support
+
arm64.nomops [ARM64] Unconditionally disable Memory Copy and Memory
Set instructions support
+ arm64.nopauth [ARM64] Unconditionally disable Pointer Authentication
+ support
+
arm64.nomte [ARM64] Unconditionally disable Memory Tagging Extension
support
diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index 3addc09f8746..cc059ba39d58 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -99,6 +99,7 @@ static const struct ftr_set_desc pfr1 __initconst = {
.override = &id_aa64pfr1_override,
.fields = {
FIELD("bt", ID_AA64PFR1_EL1_BT_SHIFT, NULL ),
+ FIELD("gcs", ID_AA64PFR1_EL1_GCS_SHIFT, NULL),
FIELD("mte", ID_AA64PFR1_EL1_MTE_SHIFT, NULL),
FIELD("sme", ID_AA64PFR1_EL1_SME_SHIFT, pfr1_sme_filter),
{}
@@ -178,6 +179,7 @@ static const struct {
{ "arm64.nosve", "id_aa64pfr0.sve=0" },
{ "arm64.nosme", "id_aa64pfr1.sme=0" },
{ "arm64.nobti", "id_aa64pfr1.bt=0" },
+ { "arm64.nogcs", "id_aa64pfr1.gcs=0" },
{ "arm64.nopauth",
"id_aa64isar1.gpi=0 id_aa64isar1.gpa=0 "
"id_aa64isar1.api=0 id_aa64isar1.apa=0 "
--
2.30.2
