On Fri, Sep 23, 2022 at 7:12 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > This patch still misses the debug info for *.S files > for the combination of LLVM_IAS=0 and > CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y > because, as the comment says, Clang does not pass -g down to GAS. > > > With "[v4] Makefile.debug: set -g unconditional on CONFIG_DEBUG_INFO_SPLIT" > and this one applied, > > > > $ grep CONFIG_DEBUG_INFO_DWARF .config > CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y > # CONFIG_DEBUG_INFO_DWARF4 is not set > # CONFIG_DEBUG_INFO_DWARF5 is not set > $ make LLVM=1 LLVM_IAS=0 arch/x86/kernel/irqflags.o > SYNC include/config/auto.conf.cmd > SYSHDR arch/x86/include/generated/asm/unistd_32_ia32.h > SYSHDR arch/x86/include/generated/asm/unistd_64_x32.h > SYSTBL arch/x86/include/generated/asm/syscalls_64.h > HOSTCC arch/x86/tools/relocs_32.o > [snip] > AS arch/x86/kernel/irqflags.o > $ objdump -h arch/x86/kernel/irqflags.o | grep debug > $ > > > > > > > > > I think the following fix-up is needed on top. > > > > > diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug > index d6aecd78b942..8cf1cb22dd93 100644 > --- a/scripts/Makefile.debug > +++ b/scripts/Makefile.debug > @@ -1,4 +1,5 @@ > -DEBUG_CFLAGS := -g > +DEBUG_CFLAGS := > +debug-flags-y := -g > > ifdef CONFIG_DEBUG_INFO_SPLIT > DEBUG_CFLAGS += -gsplit-dwarf > > > > > Then, I can see the debug sections. > > > > $ make LLVM=1 LLVM_IAS=0 arch/x86/kernel/irqflags.o > CALL scripts/checksyscalls.sh > DESCEND objtool > AS arch/x86/kernel/irqflags.o > $ objdump -h arch/x86/kernel/irqflags.o | grep debug > 6 .debug_line 00000050 0000000000000000 0000000000000000 0000008f 2**0 > 7 .debug_info 0000002e 0000000000000000 0000000000000000 000000f8 2**0 > 8 .debug_abbrev 00000014 0000000000000000 0000000000000000 000001d0 2**0 > 9 .debug_aranges 00000030 0000000000000000 0000000000000000 000001f0 2**4 > 10 .debug_str 0000004d 0000000000000000 0000000000000000 00000250 2**0 > > > > > > If you agree, I can locally fix it up as such. Ah, sorry I missed testing that combination. Thanks for your thoroughness. Yes please apply that diff on top. -- Thanks, ~Nick Desaulniers
