From 018b05e0f05bf010d82bb0e379165ecce537b2aa Mon Sep 17 00:00:00 2001 From: Nick Desaulniers Date: Mon, 9 Nov 2020 10:35:28 -0800 Subject: [PATCH] Kbuild: do not emit debug info for assembly with LLVM_IAS=1 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: Link: https://github.com/ClangBuiltLinux/linux/issues/716 Reported-by: Dmitry Golovin Reported-by: Nathan Chancellor Suggested-by: Dmitry Golovin Suggested-by: Nathan Chancellor Suggested-by: Sedat Dilek Reviewed-by: Fangrui Song Reviewed-by: Nathan Chancellor Signed-off-by: Nick Desaulniers Signed-off-by: Masahiro Yamada [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 --- Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Makefile b/Makefile index eee1aa092ede..de8b464aa1a3 100644 --- a/Makefile +++ b/Makefile @@ -802,8 +802,11 @@ 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