From: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> commit b8a9092330da2030496ff357272f342eb970d51b upstream. Clang's integrated assembler produces the warning for assembly files: warning: DWARF2 only supports one section per compilation unit If -Wa,-gdwarf-* is unspecified, then debug info is not emitted for assembly sources (it is still emitted for C sources). This will be re-enabled for newer DWARF versions in a follow up patch. Enables defconfig+CONFIG_DEBUG_INFO to build cleanly with LLVM=1 LLVM_IAS=1 for x86_64 and arm64. Cc: <stable@xxxxxxxxxxxxxxx> Link: https://github.com/ClangBuiltLinux/linux/issues/716 Reported-by: Dmitry Golovin <dima@xxxxxxxxxx> Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Suggested-by: Dmitry Golovin <dima@xxxxxxxxxx> Suggested-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Suggested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> Reviewed-by: Fangrui Song <maskray@xxxxxxxxxx> Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> [nd: backport to avoid conflicts from: commit 10e68b02c861 ("Makefile: support compressed debug info") commit 7b16994437c7 ("Makefile: Improve compressed debug info support detection") commit 695afd3d7d58 ("kbuild: Simplify DEBUG_INFO Kconfig handling")] Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- Makefile | 3 +++ 1 file changed, 3 insertions(+) --- a/Makefile +++ b/Makefile @@ -745,8 +745,11 @@ KBUILD_CFLAGS += $(call cc-option, -gs else KBUILD_CFLAGS += -g endif +ifneq ($(LLVM_IAS),1) KBUILD_AFLAGS += -Wa,-gdwarf-2 endif +endif + ifdef CONFIG_DEBUG_INFO_DWARF4 KBUILD_CFLAGS += $(call cc-option, -gdwarf-4,) endif
