[PATCH] powerpc: remove unused *_syscall_64.o variables in Makefile

[PATCH] powerpc: remove unused *_syscall_64.o variables in Makefile

[Masahiro Yamada]

Commit ab1a517d55b0 ("powerpc/syscall: Rename syscall_64.c into
interrupt.c") missed to update these three lines:

  GCOV_PROFILE_syscall_64.o := n
  KCOV_INSTRUMENT_syscall_64.o := n
  UBSAN_SANITIZE_syscall_64.o := n

To restore the original behavior, we could replace them with:

  GCOV_PROFILE_interrupt.o := n
  KCOV_INSTRUMENT_interrupt.o := n
  UBSAN_SANITIZE_interrupt.o := n

However, nobody has noticed the functional change in the past three
years, so they were unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 arch/powerpc/kernel/Makefile | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2919433be355..72d1cd6443bc 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -191,9 +191,6 @@ GCOV_PROFILE_kprobes-ftrace.o := n
 KCOV_INSTRUMENT_kprobes-ftrace.o := n
 KCSAN_SANITIZE_kprobes-ftrace.o := n
 UBSAN_SANITIZE_kprobes-ftrace.o := n
-GCOV_PROFILE_syscall_64.o := n
-KCOV_INSTRUMENT_syscall_64.o := n
-UBSAN_SANITIZE_syscall_64.o := n
 UBSAN_SANITIZE_vdso.o := n
 
 # Necessary for booting with kcov enabled on book3e machines
-- 
2.40.1

Re: [PATCH] powerpc: remove unused *_syscall_64.o variables in Makefile

[Masahiro Yamada]

+To: Daniel Axtens



Maybe, we should check if the issue fixed by
2f26ed1764b42a8c40d9c48441c73a70d805decf
came back.





On Fri, Feb 16, 2024 at 10:55 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> Commit ab1a517d55b0 ("powerpc/syscall: Rename syscall_64.c into
> interrupt.c") missed to update these three lines:
>
>   GCOV_PROFILE_syscall_64.o := n
>   KCOV_INSTRUMENT_syscall_64.o := n
>   UBSAN_SANITIZE_syscall_64.o := n
>
> To restore the original behavior, we could replace them with:
>
>   GCOV_PROFILE_interrupt.o := n
>   KCOV_INSTRUMENT_interrupt.o := n
>   UBSAN_SANITIZE_interrupt.o := n
>
> However, nobody has noticed the functional change in the past three
> years, so they were unneeded.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
>
>  arch/powerpc/kernel/Makefile | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index 2919433be355..72d1cd6443bc 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -191,9 +191,6 @@ GCOV_PROFILE_kprobes-ftrace.o := n
>  KCOV_INSTRUMENT_kprobes-ftrace.o := n
>  KCSAN_SANITIZE_kprobes-ftrace.o := n
>  UBSAN_SANITIZE_kprobes-ftrace.o := n
> -GCOV_PROFILE_syscall_64.o := n
> -KCOV_INSTRUMENT_syscall_64.o := n
> -UBSAN_SANITIZE_syscall_64.o := n
>  UBSAN_SANITIZE_vdso.o := n
>
>  # Necessary for booting with kcov enabled on book3e machines
> --
> 2.40.1
>


-- 
Best Regards
Masahiro Yamada

Re: [PATCH] powerpc: remove unused *_syscall_64.o variables in Makefile

[Michael Ellerman]

Masahiro Yamada <masahiroy@kernel.org> writes:
> +To: Daniel Axtens

Unfortunately dja doesn't work on the kernel anymore.

> Maybe, we should check if the issue fixed by
> 2f26ed1764b42a8c40d9c48441c73a70d805decf
> came back.

That crash is specific to Power8, which probably no one is running
syzkaller on anymore.

If I enable KCOV and boot with 1T segments disabled (to make it easier
to trigger the bug) it crashes similarly to the report in that commit.

> On Fri, Feb 16, 2024 at 10:55 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
...
>> To restore the original behavior, we could replace them with:
>>
>>   GCOV_PROFILE_interrupt.o := n
>>   KCOV_INSTRUMENT_interrupt.o := n
>>   UBSAN_SANITIZE_interrupt.o := n

But just putting those back isn't actually enough to fix it, the code
has changed and there are other places that need KCOV disabled on P8.

So I'm not sure how to handle this one. I guess I might just take it and
then make a todo to fix the KCOV problems later.

cheers

Re: [PATCH] powerpc: remove unused *_syscall_64.o variables in Makefile

[Michael Ellerman]

On Fri, 16 Feb 2024 22:55:17 +0900, Masahiro Yamada wrote:
> Commit ab1a517d55b0 ("powerpc/syscall: Rename syscall_64.c into
> interrupt.c") missed to update these three lines:
> 
>   GCOV_PROFILE_syscall_64.o := n
>   KCOV_INSTRUMENT_syscall_64.o := n
>   UBSAN_SANITIZE_syscall_64.o := n
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc: remove unused *_syscall_64.o variables in Makefile
      https://git.kernel.org/powerpc/c/4f1dad618587fa2fa903235301111c8c382b6f3e

cheers