Re: [PATCH 4/8] selftests: livepatch: functions: Introduce check_sysfs_exists

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

On Fri, Mar 13, 2026 at 05:58:35PM -0300, Marcos Paulo de Souza wrote:
> Return 0 if the livepatch sysfs attribute don't exists, and 1 otherwise.
> This new function will be used in the next patches.
> 
> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
> ---
>  tools/testing/selftests/livepatch/functions.sh | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
> index 8ec0cb64ad94a..781346d6e94e0 100644
> --- a/tools/testing/selftests/livepatch/functions.sh
> +++ b/tools/testing/selftests/livepatch/functions.sh
> @@ -339,6 +339,20 @@ function check_result {
>  	fi
>  }
>  
> +# check_sysfs_exists(modname, attr) - check sysfs attribute existence
> +#	modname - livepatch module creating the sysfs interface
> +#	attr - attribute name to be checked
> +function check_sysfs_exists() {
> +	local mod="$1"; shift
> +	local attr="$1"; shift
> +
> +	if [[ ! -f "$SYSFS_KLP_DIR/$mod/$attr" ]]; then
> +		return 0
> +	fi
> +
> +	return 1
> +}
> +

I don't have my shell coding hat on, but a few questions:

1. I thought shell functions usually returned 1 for a failed result and
   0 on success?

2. Could this be reduced to (assuming inverting the return as well):

  function check_sysfs_exists() {
  	local mod="$1"; shift
  	local attr="$1"; shift
  
  	[[ -f "$SYSFS_KLP_DIR/$mod/$attr" ]]
  }

3. A higher level question, but the other check_* functions will die
   "reason" on failure.  Would it be better to name this one with
   does_sysfs_exist() to indicate that subtle difference?  (Or "has" or
   some other kind of prefix.)

Regards,
--
Joe