6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Xi Ruoyao xry111@xry111.site
[ Upstream commit 120dd4118e58dbda2ddb1dcf55f3c56cdfe8cee0 ]
GAS <= 2.41 does not support generating R_LARCH_{32,64}_PCREL for "label - ." and it generates R_LARCH_{ADD,SUB}{32,64} pairs instead. Objtool cannot handle R_LARCH_{ADD,SUB}{32,64} pair in __jump_table (static key implementation) and etc. so it will produce some warnings. This is causing the kernel CI systems to complain everywhere.
For GAS we can check if -mthin-add-sub option is available to know if R_LARCH_{32,64}_PCREL are supported.
For Clang, we require Clang >= 18 and Clang >= 17 already supports R_LARCH_{32,64}_PCREL. But unfortunately Clang has some other issues, so we disable objtool for Clang at present.
Note that __jump_table here is not generated by the compiler, so -fno-jump-table is completely irrelevant for this issue.
Fixes: cb8a2ef0848c ("LoongArch: Add ORC stack unwinder support") Closes: https://lore.kernel.org/loongarch/Zl5m1ZlVmGKitAof@yujie-X299/ Closes: https://lore.kernel.org/loongarch/ZlY1gDDPi_mNrwJ1@slm.duckdns.org/ Closes: https://lore.kernel.org/loongarch/1717478006.038663-1-hengqi@linux.alibaba.c... Link: https://sourceware.org/git/?p=binutils-gdb.git%3Ba=commitdiff%3Bh=816029e067... Link: https://github.com/llvm/llvm-project/commit/42cb3c6346fc Signed-off-by: Xi Ruoyao xry111@xry111.site Signed-off-by: Huacai Chen chenhuacai@loongson.cn Signed-off-by: Sasha Levin sashal@kernel.org --- arch/loongarch/Kconfig | 5 ++++- arch/loongarch/Kconfig.debug | 1 + 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 54ad04dacdee9..d1b94ce58f793 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -138,7 +138,7 @@ config LOONGARCH select HAVE_LIVEPATCH select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI - select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS + select HAVE_OBJTOOL if AS_HAS_EXPLICIT_RELOCS && AS_HAS_THIN_ADD_SUB && !CC_IS_CLANG select HAVE_PCI select HAVE_PERF_EVENTS select HAVE_PERF_REGS @@ -257,6 +257,9 @@ config AS_HAS_EXPLICIT_RELOCS config AS_HAS_FCSR_CLASS def_bool $(as-instr,movfcsr2gr $t0$(comma)$fcsr0)
+config AS_HAS_THIN_ADD_SUB + def_bool $(cc-option,-Wa$(comma)-mthin-add-sub) + config AS_HAS_LSX_EXTENSION def_bool $(as-instr,vld $vr0$(comma)$a0$(comma)0)
diff --git a/arch/loongarch/Kconfig.debug b/arch/loongarch/Kconfig.debug index 98d60630c3d4b..8b2ce5b5d43e8 100644 --- a/arch/loongarch/Kconfig.debug +++ b/arch/loongarch/Kconfig.debug @@ -28,6 +28,7 @@ config UNWINDER_PROLOGUE
config UNWINDER_ORC bool "ORC unwinder" + depends on HAVE_OBJTOOL select OBJTOOL help This option enables the ORC (Oops Rewind Capability) unwinder for