Commit 77b0bf55bc67 ("kbuild/Makefile: Prepare for using macros in
inline assembly code to work around asm() related GCC inlining bugs")
added this flag to KBUILD_CFLAGS, where it works perfectly fine with
GCC. However, when building with Clang, all of the object files compile
fine but the build hangs indefinitely at init/main.o, right before the
linking stage. Don't include this flag when building with Clang.The kernel builds and boots to a shell in QEMU with both GCC and Clang with this patch applied. Link: https://github.com/ClangBuiltLinux/linux/issues/213 Signed-off-by: Nathan Chancellor <natechancel...@gmail.com> --- The reason this patch is labeled RFC is while I can verify that this fixes the issue, I'm not entirely sure why the '-Wa,-' works for GCC and not Clang. I looked into what the flag means and I couldn't really find anything so I just assume it's taking input from stdin? The issue could stem from how GCC forks gas versus how Clang does it. If this isn't of concern and the maintainers are happy with this patch as is, feel free to take it. arch/x86/Makefile | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 5b562e464009..4736dcc1caec 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -239,7 +239,10 @@ archheaders: archmacros: $(Q)$(MAKE) $(build)=arch/x86/kernel arch/x86/kernel/macros.s -ASM_MACRO_FLAGS = -Wa,arch/x86/kernel/macros.s -Wa,- +ASM_MACRO_FLAGS = -Wa,arch/x86/kernel/macros.s +ifneq ($(cc-name),clang) +ASM_MACRO_FLAGS += -Wa,- +endif export ASM_MACRO_FLAGS KBUILD_CFLAGS += $(ASM_MACRO_FLAGS) -- 2.19.1
