[PATCH 14/14] klp-build: Support cross-compilation

[Josh Poimboeuf <jpoimboe@kernel.org>]

Add support for cross-compilation.  The user must export ARCH, and
either CROSS_COMPILE or LLVM.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 scripts/livepatch/klp-build | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/scripts/livepatch/klp-build b/scripts/livepatch/klp-build
index 809e198a561d..b6c057e2120f 100755
--- a/scripts/livepatch/klp-build
+++ b/scripts/livepatch/klp-build
@@ -404,6 +404,14 @@ validate_patches() {
 	revert_patches
 }
 
+cross_compile_init() {
+	if [[ -v LLVM ]]; then
+		OBJCOPY=llvm-objcopy
+	else
+		OBJCOPY="${CROSS_COMPILE:-}objcopy"
+	fi
+}
+
 do_init() {
 	# We're not yet smart enough to handle anything other than in-tree
 	# builds in pwd.
@@ -420,6 +428,7 @@ do_init() {
 	validate_config
 	set_module_name
 	set_kernelversion
+	cross_compile_init
 }
 
 # Refresh the patch hunk headers, specifically the line numbers and counts.
@@ -783,7 +792,7 @@ build_patch_module() {
 	cp -f "$kmod_file" "$kmod_file.orig"
 
 	# Work around issue where slight .config change makes corrupt BTF
-	objcopy --remove-section=.BTF "$kmod_file"
+	"$OBJCOPY" --remove-section=.BTF "$kmod_file"
 
 	# Fix (and work around) linker wreckage for klp syms / relocs
 	"$SRC/tools/objtool/objtool" klp post-link "$kmod_file" || die "objtool klp post-link failed"
-- 
2.53.0