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From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Mon, 27 Mar 2023 01:34:09 +0900
Message-ID: <CAK7LNARyn3R3BRxJ0Wdd_djTNQQR3Qh56jXAhR+gzgTsPY7Xew@mail.gmail.com>
Subject: Re: [PATCH] purgatory: fix disabling debug info
To:     Alyssa Ross <hi@alyssa.is>
Cc:     Nick Cao <nickcao@nichi.co>, linux-kbuild@vger.kernel.org,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nathan Chancellor <nathan@kernel.org>,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        linux-riscv@lists.infradead.org, Tom Rix <trix@redhat.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        stable@vger.kernel.org
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On Mon, Mar 27, 2023 at 12:35=E2=80=AFAM Alyssa Ross <hi@alyssa.is> wrote:
>
> Since 32ef9e5054ec, -Wa,-gdwarf-2 is no longer used in KBUILD_AFLAGS.
> Instead, it includes -g, the appropriate -gdwarf-* flag, and also the
> -Wa versions of both of those if building with Clang and GNU as.  As a
> result, debug info was being generated for the purgatory objects, even
> though the intention was that it not be.
>
> Fixes: 32ef9e5054ec ("Makefile.debug: re-enable debug info for .S files")
> Signed-off-by: Alyssa Ross <hi@alyssa.is>
> Cc: stable@vger.kernel.org
> ---
>  arch/riscv/purgatory/Makefile | 12 ++++++------
>  arch/x86/purgatory/Makefile   |  4 ++--
>  2 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/arch/riscv/purgatory/Makefile b/arch/riscv/purgatory/Makefil=
e
> index d16bf715a586..97001798fa19 100644
> --- a/arch/riscv/purgatory/Makefile
> +++ b/arch/riscv/purgatory/Makefile
> @@ -84,12 +84,12 @@ CFLAGS_string.o                     +=3D $(PURGATORY_=
CFLAGS)
>  CFLAGS_REMOVE_ctype.o          +=3D $(PURGATORY_CFLAGS_REMOVE)
>  CFLAGS_ctype.o                 +=3D $(PURGATORY_CFLAGS)
>
> -AFLAGS_REMOVE_entry.o          +=3D -Wa,-gdwarf-2
> -AFLAGS_REMOVE_memcpy.o         +=3D -Wa,-gdwarf-2
> -AFLAGS_REMOVE_memset.o         +=3D -Wa,-gdwarf-2
> -AFLAGS_REMOVE_strcmp.o         +=3D -Wa,-gdwarf-2
> -AFLAGS_REMOVE_strlen.o         +=3D -Wa,-gdwarf-2
> -AFLAGS_REMOVE_strncmp.o                +=3D -Wa,-gdwarf-2
> +AFLAGS_REMOVE_entry.o          +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-g=
dwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_memcpy.o         +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-g=
dwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_memset.o         +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-g=
dwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_strcmp.o         +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-g=
dwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_strlen.o         +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-g=
dwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_strncmp.o                +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-=
g -Wa,-gdwarf4 -Wa,-gdwarf-5


You can merge these into a single line:

 asflags-remove-y +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwa=
rf-5


Or, a slightly shorter but tricky way is:

 asflags-remove-y +=3D $(foreach x, -g -gdwarf-4 -gdwarf-5, $(x) -Wa,$(x))


>  $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
>                 $(call if_changed,ld)
> diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
> index 17f09dc26381..f1b1ef6c4cbf 100644
> --- a/arch/x86/purgatory/Makefile
> +++ b/arch/x86/purgatory/Makefile
> @@ -69,8 +69,8 @@ CFLAGS_sha256.o                       +=3D $(PURGATORY_=
CFLAGS)
>  CFLAGS_REMOVE_string.o         +=3D $(PURGATORY_CFLAGS_REMOVE)
>  CFLAGS_string.o                        +=3D $(PURGATORY_CFLAGS)
>
> -AFLAGS_REMOVE_setup-x86_$(BITS).o      +=3D -Wa,-gdwarf-2
> -AFLAGS_REMOVE_entry64.o                        +=3D -Wa,-gdwarf-2
> +AFLAGS_REMOVE_setup-x86_$(BITS).o      +=3D -g -gdwarf-4 -gdwarf-5 -Wa,-=
g -Wa,-gdwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_entry64.o                        +=3D -g -gdwarf-4 -gdwarf=
-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5


Ditto.


Thanks.


>  $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
>                 $(call if_changed,ld)
>
> base-commit: da8e7da11e4ba758caf4c149cc8d8cd555aefe5f
> --
> 2.37.1
>


--=20
Best Regards
Masahiro Yamada