[OE-core] [PATCH 4/4] kernel: add objtool to shared workdir when CONFIG_UNWINDER_ORC is set

[bruce.ashfield at gmail.com]

From: Justin Bronder <jsbronder at cold-front.org>

Based on: https://patchwork.openembedded.org/patch/148047/

When x86_64 enables CONFIG_UNWINDER_ORC [ORC (Oops Rewind Capability)
unwinder for unwinding kernel stack traces], objtool is required to
generate the required information.

If we don't copy objtool to the shared workdir, out-of-tree modules
cannot generate object files.

For instance, meta-skeleton/hello-mod fails with:
    | make[3]: *** No rule to make target 'tools/objtool/objtool', needed by ...

Signed-off-by: Bruce Ashfield <bruce.ashfield at gmail.com>
---
 meta/classes/kernel.bbclass | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index a5b1df1b0d..9da9818962 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -487,6 +487,15 @@ do_shared_workdir () {
 		mkdir -p $kerneldir/arch/${ARCH}/include/generated/
 		cp -fR arch/${ARCH}/include/generated/* $kerneldir/arch/${ARCH}/include/generated/
 	fi
+
+	if (grep -q -i -e '^CONFIG_UNWINDER_ORC=y$' $kerneldir/.config); then
+		# With CONFIG_UNWINDER_ORC (the default in 4.14), objtool is required for
+		# out-of-tree modules to be able to generate object files.
+		if [ -x tools/objtool/objtool ]; then
+			mkdir -p ${kerneldir}/tools/objtool
+			cp tools/objtool/objtool ${kerneldir}/tools/objtool/
+		fi
+	fi
 }
 
 # We don't need to stage anything, not the modules/firmware since those would clash with linux-firmware
-- 
2.19.1