[PATCH] kbuild: use objtool-args-y to clean up objtool arguments

From: Masahiro Yamada
Date: Fri Sep 02 2022 - 10:12:19 EST


Based on Linus' patch.

Link: https://lore.kernel.org/lkml/CAHk-=wgjTMQgiKzBZTmb=uWGDEQxDdyF1+qxBkODYciuNsmwnw@xxxxxxxxxxxxxx/
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

scripts/Makefile.lib | 31 ++++++++++++++++---------------
scripts/Makefile.vmlinux_o | 17 ++++++++---------
2 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index b594705d571a..731f735240f8 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -229,25 +229,26 @@ ifdef CONFIG_OBJTOOL

objtool := $(objtree)/tools/objtool/objtool

-objtool_args = \
- $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
- $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
- $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
- $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
- $(if $(CONFIG_UNWINDER_ORC), --orc) \
- $(if $(CONFIG_RETPOLINE), --retpoline) \
- $(if $(CONFIG_RETHUNK), --rethunk) \
- $(if $(CONFIG_SLS), --sls) \
- $(if $(CONFIG_STACK_VALIDATION), --stackval) \
- $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \
- $(if $(CONFIG_HAVE_UACCESS_VALIDATION), --uaccess) \
+objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label
+objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr
+objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt
+objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount
+objtool-args-$(CONFIG_UNWINDER_ORC) += --orc
+objtool-args-$(CONFIG_RETPOLINE) += --retpoline
+objtool-args-$(CONFIG_RETHUNK) += --rethunk
+objtool-args-$(CONFIG_SLS) += --sls
+objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval
+objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call
+objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess
+objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable
+
+objtool-args = $(objtool-args-y) \
$(if $(delay-objtool), --link) \
- $(if $(part-of-module), --module) \
- $(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
+ $(if $(part-of-module), --module)

delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))

-cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
+cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)

endif # CONFIG_OBJTOOL
diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o
index 81a4e0484457..df928a6717a1 100644
--- a/scripts/Makefile.vmlinux_o
+++ b/scripts/Makefile.vmlinux_o
@@ -35,18 +35,17 @@ endif

objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION))

-# Reuse objtool_args defined in scripts/Makefile.lib if LTO or IBT is enabled.
+# Reuse objtool-args-y defined in scripts/Makefile.lib if LTO or IBT is enabled.
+# (Expand objtool-args-y to a simple variable to avoid circular reference)
#
# Add some more flags as needed.
-# --no-unreachable and --link might be added twice, but it is fine.
-#
-# Expand objtool_args to a simple variable to avoid circular reference.
+# --no-unreachable might be added twice, but it is fine.
+
+objtool-args-$(delay-objtool) := $(objtool-args-y)
+objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable
+objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr $(if $(CONFIG_CPU_UNRET_ENTRY), --unret))

-objtool_args := \
- $(if $(delay-objtool),$(objtool_args)) \
- $(if $(CONFIG_NOINSTR_VALIDATION), --noinstr $(if $(CONFIG_CPU_UNRET_ENTRY), --unret)) \
- $(if $(CONFIG_GCOV_KERNEL), --no-unreachable) \
- --link
+objtool-args = $(objtool-args-y) --link

# Link of vmlinux.o used for section mismatch analysis
# ---------------------------------------------------------------------------
--
2.34.1