The upcoming module hashes functionality will build the modules in
between the generation of the BTF data and the final link of vmlinux.
Having a dependency from the modules on vmlinux would make this
impossible as it would mean having a cyclic dependency.
Break this cyclic dependency by introducing a new target.
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
scripts/Makefile.modfinal | 4 ++--
scripts/link-vmlinux.sh | 6 ++++++
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 542ba462ed3ec9607e0df10e26613a4c7ac318e8..5d01b553ec9a4565c8e5a6edd05665c409003bc1 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -52,8 +52,8 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \
printf '%s\n' 'savedcmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
# 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),$(objtree)/vmlinux) FORCE
- +$(call if_changed_except,ld_ko_o,$(objtree)/vmlinux)
+%.ko: %.o %.mod.o .module-common.o $(objtree)/scripts/module.lds $(and $(CONFIG_DEBUG_INFO_BTF_MODULES),$(KBUILD_BUILTIN),$(objtree)/.tmp_vmlinux_btf.stamp) FORCE
+ +$(call if_changed_except,ld_ko_o,$(objtree)/.tmp_vmlinux_btf.stamp)
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
+$(if $(newer-prereqs),$(call cmd,btf_ko))
endif
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index d853ddb3b28c1238ec9079ebbbe77df26980a0a1..803c8d6f35a7f29fb68b29afa8546f4dde0bd4cb 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -112,6 +112,7 @@ vmlinux_link()
gen_btf()
{
local btf_data=${1}.btf.o
+ local btf_stamp=.tmp_vmlinux_btf.stamp
info BTF "${btf_data}"
LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
@@ -132,6 +133,11 @@ gen_btf()
fi
printf "${et_rel}" | dd of="${btf_data}" conv=notrunc bs=1 seek=16 status=none
+ info STAMP $btf_stamp
+ if ! cmp --silent $btf_data $btf_stamp; then
+ cp $btf_data $btf_stamp
+ fi
+
btf_vmlinux_bin_o=${btf_data}
}
--
2.47.1
