feat(cpufeat): enable FEAT_PAuth to FEAT_STATE_CHECKED
FEAT_PAuth is the second to last feature to be a boolean choice - it's
either unconditionally compiled in and must be present in hardware or
it's not compiled in. FEAT_PAuth is architected to be backwards
compatible - a subset of the branch guarding instructions (pacia/autia)
execute as NOPs when PAuth is not present. That subset is used with
`-mbranch-protection=standard` and -march pre-8.3. This patch adds the
necessary logic to also check accesses of the non-backward compatible
registers and allow a fully checked implementation.
Note that a checked support requires -march to be pre 8.3, as otherwise
the compiler will include branch protection instructions that are not
NOPs without PAuth (eg retaa) which cannot be checked.
Change-Id: Id942c20cae9d15d25b3d72b8161333642574ddaa
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
diff --git a/plat/qemu/common/common.mk b/plat/qemu/common/common.mk
index da981e5..751511c 100644
--- a/plat/qemu/common/common.mk
+++ b/plat/qemu/common/common.mk
@@ -148,7 +148,7 @@
endif
# Pointer Authentication sources
-ifeq ($(BRANCH_PROTECTION),$(filter $(BRANCH_PROTECTION),1 2 3))
+ifeq ($(BRANCH_PROTECTION),$(filter $(BRANCH_PROTECTION),1 2 3 5))
PLAT_BL_COMMON_SOURCES += plat/arm/common/aarch64/arm_pauth.c
endif