Re: [PATCH 09/10] selftests/damon/sysfs_memcg_path_leak: fail only for real DAMON leak

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] selftests/damon: test falsely passes on minimal grep due to --quiet flag
--

commit 3a025795f6efb7b8edc7858f005049159a83efbe
Author: SJ Park <sj@kernel.org>

selftests/damon/sysfs_memcg_path_leak: fail only for real DAMON leak

This commit updates the DAMON sysfs_memcg_path_leak selftest to explicitly
check the kmemleak report for "memcg_path_store". It exits with success if the
leak doesn't appear to be related to DAMON, reducing false positive failures.

> diff --git a/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh b/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh
> --- a/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh
> +++ b/tools/testing/selftests/damon/sysfs_memcg_path_leak.sh
> @@ -41,5 +41,12 @@ if [ "$kmemleak_report" = "" ]
>  then
>  	exit 0
>  fi
> +if ! echo "$kmemleak_report" | grep "memcg_path_store" --quiet

[Severity: Medium]
Will this script falsely pass in environments with a minimal grep
implementation?

If this selftest is executed in an environment (like some BusyBox builds or
Alpine Linux) where grep does not support the GNU --quiet extension, grep
will exit with an error code. 

The ! operator will negate this non-zero exit code, causing the condition
to evaluate to true. The script will then enter the then block and exit
successfully (exit 0), potentially masking real kernel memory leaks.

Could this use -q instead of --quiet to be more portable?

> +then
> +	echo "[WARN] memleak found; apparently not from DAMON, though"
> +	echo "$kmemleak_report"
> +	exit 0
> +fi
> +
>  echo "$kmemleak_report"
>  exit 1

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Sashiko AI review · https://sashiko.dev/#/patchset/20260917142210.90829-1-sj@kernel.org?part=9