[PATCH 1/9] scripts/link-vmlinux.sh: Delay orphan handling warnings until final link

[Kees Cook]

Right now, powerpc adds "--orphan-handling=warn" to LD_FLAGS_vmlinux
to detect when there are unexpected sections getting added to the kernel
image. There is no need to report these warnings more than once, so it
can be removed until the final link stage.

This helps pave the way for other architectures to enable this, with the
end goal of enabling this warning by default for vmlinux for all
architectures.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 scripts/link-vmlinux.sh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 1919c311c149..416968fea685 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -255,6 +255,11 @@ info GEN modules.builtin
 tr '\0' '\n' < modules.builtin.modinfo | sed -n 's/^[[:alnum:]:_]*\.file=//p' |
 	tr ' ' '\n' | uniq | sed -e 's:^:kernel/:' -e 's/$/.ko/' > modules.builtin
 
+
+# Do not warn about orphan sections until the final link stage.
+saved_LDFLAGS_vmlinux="${LDFLAGS_vmlinux}"
+LDFLAGS_vmlinux="$(echo "${LDFLAGS_vmlinux}" | sed -E 's/ --orphan-handling=warn( |$)/ /g')"
+
 btf_vmlinux_bin_o=""
 if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
 	if gen_btf .tmp_vmlinux.btf .btf.vmlinux.bin.o ; then
@@ -306,6 +311,7 @@ if [ -n "${CONFIG_KALLSYMS}" ]; then
 	fi
 fi
 
+LDFLAGS_vmlinux="${saved_LDFLAGS_vmlinux}"
 vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
 
 if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
-- 
2.20.1