Nathan reported that when building with GNU as and a version of clang that defaults to DWARF5: $ make -skj"$(nproc)" ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \ LLVM=1 LLVM_IAS=0 O=build \ mrproper allmodconfig mm/kfence/kfence_test.o /tmp/kfence_test-08a0a0.s: Assembler messages: /tmp/kfence_test-08a0a0.s:14627: Error: non-constant .uleb128 is not supported /tmp/kfence_test-08a0a0.s:14628: Error: non-constant .uleb128 is not supported /tmp/kfence_test-08a0a0.s:14632: Error: non-constant .uleb128 is not supported /tmp/kfence_test-08a0a0.s:14633: Error: non-constant .uleb128 is not supported /tmp/kfence_test-08a0a0.s:14639: Error: non-constant .uleb128 is not supported ... This is because `-g` defaults to the compiler debug info default. If the assembler does not support some of the directives used, the above errors occur. To fix, remove the explicit passing of `-g`. All these tests want is that stack traces print valid function names, and debug info is not required for that. I currently cannot recall why I added the explicit `-g`. Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx> Signed-off-by: Marco Elver <elver@xxxxxxxxxx> --- kernel/kcsan/Makefile | 2 +- mm/kfence/Makefile | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile index 8cf70f068d92..a45f3dfc8d14 100644 --- a/kernel/kcsan/Makefile +++ b/kernel/kcsan/Makefile @@ -16,6 +16,6 @@ obj-y := core.o debugfs.o report.o KCSAN_INSTRUMENT_BARRIERS_selftest.o := y obj-$(CONFIG_KCSAN_SELFTEST) += selftest.o -CFLAGS_kcsan_test.o := $(CFLAGS_KCSAN) -g -fno-omit-frame-pointer +CFLAGS_kcsan_test.o := $(CFLAGS_KCSAN) -fno-omit-frame-pointer CFLAGS_kcsan_test.o += $(DISABLE_STRUCTLEAK_PLUGIN) obj-$(CONFIG_KCSAN_KUNIT_TEST) += kcsan_test.o diff --git a/mm/kfence/Makefile b/mm/kfence/Makefile index 0bb95728a784..2de2a58d11a1 100644 --- a/mm/kfence/Makefile +++ b/mm/kfence/Makefile @@ -2,5 +2,5 @@ obj-y := core.o report.o -CFLAGS_kfence_test.o := -g -fno-omit-frame-pointer -fno-optimize-sibling-calls +CFLAGS_kfence_test.o := -fno-omit-frame-pointer -fno-optimize-sibling-calls obj-$(CONFIG_KFENCE_KUNIT_TEST) += kfence_test.o -- 2.40.0.rc1.284.g88254d51c5-goog