[RFC 2/3] kbuild: modules: Build and trigger BTI scanner for arm64

[Jeremy Linton]

Now that we have a utility which can detect and correct missing
landing pads, build it and hook it up to scan during module
finalization.

Signed-off-by: Jeremy Linton <jeremy.linton at arm.com>
---
 scripts/Makefile          |  3 +++
 scripts/Makefile.modfinal | 12 +++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/scripts/Makefile b/scripts/Makefile
index 3434a82a119f..10042d5d1251 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -8,6 +8,7 @@ hostprogs-always-$(BUILD_C_RECORDMCOUNT)		+= recordmcount
 hostprogs-always-$(CONFIG_BUILDTIME_TABLE_SORT)		+= sorttable
 hostprogs-always-$(CONFIG_ASN1)				+= asn1_compiler
 hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT)		+= sign-file
+hostprogs-always-$(CONFIG_ARM64_BTI_KERNEL)		+= module-bti-check
 hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE)	+= insert-sys-cert
 hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS)		+= rustdoc_test_builder
 hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS)		+= rustdoc_test_gen
@@ -32,6 +33,8 @@ rustdoc_test_gen-rust := y
 HOSTCFLAGS_tracepoint-update.o = -I$(srctree)/tools/include
 HOSTCFLAGS_elf-parse.o = -I$(srctree)/tools/include
 HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
+HOSTCFLAGS_module-bti-check.o = -I$(srctree)/tools/include
+HOSTLDLIBS_module-bti-check = -lelf
 HOSTLDLIBS_sorttable = -lpthread
 HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
 HOSTCFLAGS_sign-file.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null)
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 01a37ec872b9..973adfa72a7d 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -32,6 +32,12 @@ ifneq ($(WARN_ON_UNUSED_TRACEPOINTS),)
 cmd_check_tracepoint = $(objtree)/scripts/tracepoint-update --module $<;
 endif
 
+ifdef CONFIG_ARM64_BTI_KERNEL
+quiet_cmd_bti_check = BTICHECK [M] $@
+      cmd_bti_check = $(objtree)/scripts/module-bti-check --fix $(KBUILD_MODULE_BTI_CHECK_FLAGS) $@
+bti_check_dep = $(objtree)/scripts/module-bti-check
+endif
+
 quiet_cmd_ld_ko_o = LD [M]  $@
       cmd_ld_ko_o =							\
 	$(LD) -r $(KBUILD_LDFLAGS)					\
@@ -47,8 +53,12 @@ quiet_cmd_btf_ko = BTF [M] $@
 	fi;
 
 # Re-generate module BTFs if either module's .ko or vmlinux changed
-%.ko: %.o %.mod.o .module-common.o $(objtree)/scripts/module.lds $(and $(CONFIG_DEBUG_INFO_BTF_MODULES),$(KBUILD_BUILTIN),$(objtree)/vmlinux) FORCE
+%.ko: %.o %.mod.o .module-common.o $(objtree)/scripts/module.lds $(bti_check_dep) $(and $(CONFIG_DEBUG_INFO_BTF_MODULES),$(KBUILD_BUILTIN),$(objtree)/vmlinux) FORCE
 	+$(call if_changed,ld_ko_o)
+ifdef CONFIG_ARM64_BTI_KERNEL
+	+$(call cmd,bti_check)
+endif
+
 ifdef CONFIG_DEBUG_INFO_BTF_MODULES
 	+$(if $(newer-prereqs),$(call cmd,btf_ko))
 endif
-- 
2.55.0