Hook up an override for GCS, allowing it to be disabled from the command line by specifying arm64.nogcs in case there are problems.
Reviewed-by: Thiago Jung Bauermann thiago.bauermann@linaro.org Reviewed-by: Catalin Marinas catalin.marinas@arm.com Acked-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Mark Brown broonie@kernel.org --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ arch/arm64/kernel/pi/idreg-override.c | 2 ++ 2 files changed, 5 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1518343bbe22..c1b00f709734 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -446,6 +446,9 @@ 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
diff --git a/arch/arm64/kernel/pi/idreg-override.c b/arch/arm64/kernel/pi/idreg-override.c index 29d4b6244a6f..2bb709d78405 100644 --- a/arch/arm64/kernel/pi/idreg-override.c +++ b/arch/arm64/kernel/pi/idreg-override.c @@ -133,6 +133,7 @@ static const struct ftr_set_desc pfr1 __prel64_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), {} @@ -215,6 +216,7 @@ 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 "