2023-03-26 15:55:02

by Alyssa Ross

Subject: [PATCH] purgatory: fix disabling debug info

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 <[email protected]>
Cc: [email protected]
---
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
--
2.37.1

2023-03-26 16:40:39

by Masahiro Yamada

Subject: Re: [PATCH] purgatory: fix disabling debug info

On Mon, Mar 27, 2023 at 12:35 AM Alyssa Ross <[email protected]> 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 <[email protected]>
> Cc: [email protected]
> ---
> 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


You can merge these into a single line:

asflags-remove-y += -g -gdwarf-4 -gdwarf-5 -Wa,-g -Wa,-gdwarf4 -Wa,-gdwarf-5


Or, a slightly shorter but tricky way is:

asflags-remove-y += $(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 += $(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


Ditto.


Thanks.



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


--
Best Regards
Masahiro Yamada

2023-03-26 16:57:45

by Nick Cao

Subject: Re: [PATCH] purgatory: fix disabling debug info

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 <[email protected]>

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 <[email protected]>
> Cc: [email protected]
> ---
> 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