Re: [PATCH 1/8] selftests: livepatch: test-syscall: Check for ARCH_HAS_SYSCALL_WRAPPER

[Joe Lawrence <joe.lawrence@redhat.com>]

On Fri, Mar 13, 2026 at 05:58:32PM -0300, Marcos Paulo de Souza wrote:
> Instead of checking if the architecture running the test was powerpc,
> check if CONF_ARCH_HAS_SYSCALL_WRAPPER is defined or not.
> 
> No functional changes.
> 
> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
> ---
>  tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c b/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c
> index dd802783ea849..c01a586866304 100644
> --- a/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c
> +++ b/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c
> @@ -12,15 +12,14 @@
>  #include <linux/slab.h>
>  #include <linux/livepatch.h>
>  
> -#if defined(__x86_64__)
> +#if !defined(CONFIG_ARCH_HAS_SYSCALL_WRAPPER)
> +#define FN_PREFIX
> +#elif defined(__x86_64__)
>  #define FN_PREFIX __x64_
>  #elif defined(__s390x__)
>  #define FN_PREFIX __s390x_
>  #elif defined(__aarch64__)
>  #define FN_PREFIX __arm64_
> -#else
> -/* powerpc does not select ARCH_HAS_SYSCALL_WRAPPER */
> -#define FN_PREFIX

The patch does maintain the previous behavior, but I'm wondering if the
original assertion about ARCH_HAS_SYSCALL_WRAPPER on Power was correct:

  $ grep ARCH_HAS_SYSCALL_WRAPPER arch/powerpc/Kconfig
          select ARCH_HAS_SYSCALL_WRAPPER         if !SPU_BASE && !COMPAT
          depends on PPC64 && ARCH_HAS_SYSCALL_WRAPPER

Perhaps I just forgot what that additional piece of information that
explains the comment (highly probable these days), and if so, might be
nice to add to this commit since I don't see it in 6a71770442b5
("selftests: livepatch: Test livepatching a heavily called syscall").

Thanks,
--
Joe