selftests: Use optional USERCFLAGS and USERLDFLAGS

commit 24ff563c88c5dc36ab88e6ff8da6360c1a7e1c57 upstream.

This change enables to extend CFLAGS and LDFLAGS from command line, e.g.
to extend compiler checks: make USERCFLAGS=-Werror USERLDFLAGS=-static

USERCFLAGS and USERLDFLAGS are documented in
Documentation/kbuild/makefiles.rst and Documentation/kbuild/kbuild.rst

This should be backported (down to 5.10) to improve previous kernel
versions testing as well.

Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20220909103901.1503436-1-mic@digikod.net
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 8794ce382bf5aa925264b4a0b7f28815713d604b..59479442faa67240a5c3f97df1ea4f224c5083fe 100644 (file)
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -130,6 +130,11 @@ endef
 clean:
        $(CLEAN)
 
+# Enables to extend CFLAGS and LDFLAGS from command line, e.g.
+# make USERCFLAGS=-Werror USERLDFLAGS=-static
+CFLAGS += $(USERCFLAGS)
+LDFLAGS += $(USERLDFLAGS)
+
 # When make O= with kselftest target from main level
 # the following aren't defined.
 #