| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.9 001/105] Kbuild: do not emit debug info for assembly with LLVM_IAS=1 | Date | Mon, 14 Dec 2020 18:27:35 +0100 |
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From: Nick Desaulniers <ndesaulniers@google.com>
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@vger.kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/716 Reported-by: Dmitry Golovin <dima@golovin.in> Reported-by: Nathan Chancellor <natechancellor@gmail.com> Suggested-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Nathan Chancellor <natechancellor@gmail.com> Suggested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Fangrui Song <maskray@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> [nd: backport to avoid conflicts from: commit 695afd3d7d58 ("kbuild: Simplify DEBUG_INFO Kconfig handling")] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- Makefile | 3 +++ 1 file changed, 3 insertions(+)
--- a/Makefile +++ b/Makefile @@ -821,8 +821,11 @@ DEBUG_CFLAGS += -gsplit-dwarf else DEBUG_CFLAGS += -g endif +ifneq ($(LLVM_IAS),1) KBUILD_AFLAGS += -Wa,-gdwarf-2 endif +endif + ifdef CONFIG_DEBUG_INFO_DWARF4 DEBUG_CFLAGS += -gdwarf-4 endif
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