[RFC PATCH 4/4] LoongArch: Remove -fno-jump-tables for objtool

From: Tiezhu Yang
Date: Fri Jul 12 2024 - 05:15:35 EST


Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
arch/loongarch/Kconfig | 8 +++++++-
arch/loongarch/Makefile | 6 ++----
2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index ddc042895d01..57f28450a2ed 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -143,7 +143,7 @@ config LOONGARCH
select HAVE_LIVEPATCH
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_NMI
- select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB && !CC_IS_CLANG
+ select HAVE_OBJTOOL if TOOLCHAIN_SUPPORTS_OBJTOOL && !CC_IS_CLANG
select HAVE_PCI
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
@@ -276,6 +276,12 @@ config AS_HAS_LBT_EXTENSION
config AS_HAS_LVZ_EXTENSION
def_bool $(as-instr,hvcl 0)

+config CC_HAS_ANNOTATE_TABLEJUMP
+ def_bool $(cc-option,-mannotate-tablejump)
+
+config TOOLCHAIN_SUPPORTS_OBJTOOL
+ def_bool AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB && CC_HAS_ANNOTATE_TABLEJUMP
+
menu "Kernel type and options"

source "kernel/Kconfig.hz"
diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
index 8674e7e24c4a..186c75c80daa 100644
--- a/arch/loongarch/Makefile
+++ b/arch/loongarch/Makefile
@@ -99,10 +99,8 @@ KBUILD_AFLAGS += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno
KBUILD_CFLAGS += $(call cc-option,-mno-relax) $(call cc-option,-Wa$(comma)-mno-relax)
KBUILD_AFLAGS += $(call cc-option,-mthin-add-sub) $(call cc-option,-Wa$(comma)-mthin-add-sub)
KBUILD_CFLAGS += $(call cc-option,-mthin-add-sub) $(call cc-option,-Wa$(comma)-mthin-add-sub)
-
-ifdef CONFIG_OBJTOOL
-KBUILD_CFLAGS += -fno-jump-tables
-endif
+KBUILD_AFLAGS += $(call cc-option,-mannotate-tablejump) $(call cc-option,-Wa$(comma)-mannotate-tablejump)
+KBUILD_CFLAGS += $(call cc-option,-mannotate-tablejump) $(call cc-option,-Wa$(comma)-mannotate-tablejump)

KBUILD_RUSTFLAGS += --target=loongarch64-unknown-none-softfloat
KBUILD_RUSTFLAGS_MODULE += -Crelocation-model=pic
--
2.42.0