[PATCH] purgatory: fix disabling debug info

[Nick Cao]

With this patch applied on top of 
https://github.com/NickCao/linux/tree/f258de7fdb1e69492f8962da5d34646da49685db, 
the built kernel image no longer contains reference to the source 
directory (which is not allowed in the Nixpkgs kernel building 
infrastructure).

Tested-by: Nick Cao <nickcao at nichi.co>

On 3/26/23 23:34, Alyssa Ross 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 at alyssa.is>
> Cc: stable at 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/Makefile
> index d16bf715a586..97001798fa19 100644
> --- a/arch/riscv/purgatory/Makefile
> +++ b/arch/riscv/purgatory/Makefile
> @@ -84,12 +84,12 @@ CFLAGS_string.o			+= $(PURGATORY_CFLAGS)
>   CFLAGS_REMOVE_ctype.o		+= $(PURGATORY_CFLAGS_REMOVE)
>   CFLAGS_ctype.o			+= $(PURGATORY_CFLAGS)
>   
> -AFLAGS_REMOVE_entry.o		+= -Wa,-gdwarf-2
> -AFLAGS_REMOVE_memcpy.o		+= -Wa,-gdwarf-2
> -AFLAGS_REMOVE_memset.o		+= -Wa,-gdwarf-2
> -AFLAGS_REMOVE_strcmp.o		+= -Wa,-gdwarf-2
> -AFLAGS_REMOVE_strlen.o		+= -Wa,-gdwarf-2
> -AFLAGS_REMOVE_strncmp.o		+= -Wa,-gdwarf-2
> +AFLAGS_REMOVE_entry.o		+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_memcpy.o		+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_memset.o		+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_strcmp.o		+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_strlen.o		+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_strncmp.o		+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
>   
>   $(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			+= $(PURGATORY_CFLAGS)
>   CFLAGS_REMOVE_string.o		+= $(PURGATORY_CFLAGS_REMOVE)
>   CFLAGS_string.o			+= $(PURGATORY_CFLAGS)
>   
> -AFLAGS_REMOVE_setup-x86_$(BITS).o	+= -Wa,-gdwarf-2
> -AFLAGS_REMOVE_entry64.o			+= -Wa,-gdwarf-2
> +AFLAGS_REMOVE_setup-x86_$(BITS).o	+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
> +AFLAGS_REMOVE_entry64.o			+= -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5
>   
>   $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
>   		$(call if_changed,ld)
> 
> base-commit: da8e7da11e4ba758caf4c149cc8d8cd555aefe5f