From: sashiko-bot@kernel.org
To: "Qiliang Yuan" <odys.yuan@gmail.com>
Cc: bpf@vger.kernel.org
Subject: Re: [PATCH bpf-next v2 2/2] selftests/bpf: Unmount the bpffs that cgroup_hierarchical_stats mounted
Date: Fri, 09 Oct 2026 02:14:16 +0000 [thread overview]
Message-ID: <sashiko-outbox-164722@kernel.org> (raw)
In-Reply-To: <20261009-selftests-bpf-cgroup-stats-bpffs-v2-2-f93a111da992@gmail.com>
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] bpf: unconditional rmdir in cleanup_bpffs triggers spurious assertion failures
--
commit 34f23b53e236bfae8b2ad74d5d89f8806c601dbb
Author: Qiliang Yuan <odys.yuan@gmail.com>
selftests/bpf: Unmount the bpffs that cgroup_hierarchical_stats mounted
This commit fixes a logic error in cleanup_bpffs() where a locally mounted
bpffs was not correctly unmounted. By inverting the check on mounted_bpffs,
the test ensures it cleans up its own mounts rather than leaking them.
> diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c b/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
> index ad19d6d41918a..cc6ab2c263da1 100644
> --- a/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
> +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c
> @@ -110,7 +110,7 @@ static void cleanup_bpffs(void)
> ASSERT_OK(rmdir(BPFFS_ATTACH_COUNTERS), "rmdir "BPFFS_ATTACH_COUNTERS);
[Severity: Low]
In cleanup_bpffs() within
tools/testing/selftests/bpf/prog_tests/cgroup_hierarchical_stats.c, does this
unconditional rmdir() trigger spurious assertion failures during early setup
error paths?
When setup fails (e.g., in setup_cgroups() or the initial mount() call), the
BPFFS_ATTACH_COUNTERS directory is never created. During the teardown path
(hierarchy_cleanup() -> destroy_hierarchy() -> cleanup_bpffs()), rmdir() is
unconditionally called and wrapped in ASSERT_OK().
If the directory does not exist, rmdir() returns -ENOENT, triggering a
secondary assertion failure. This clutters the test output and masks the
original setup failure.
>
> /* Unmount bpffs, if it wasn't already mounted when we started */
> - if (mounted_bpffs)
> + if (!mounted_bpffs)
> return;
>
> ASSERT_OK(umount(BPFFS_ROOT), "unmount bpffs");
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261009-selftests-bpf-cgroup-stats-bpffs-v2-0-f93a111da992@gmail.com?part=2
prev parent reply other threads:[~2026-10-09 2:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-09 2:04 [PATCH bpf-next v2 0/2] selftests/bpf: Fix the bpffs handling of cgroup_hierarchical_stats Qiliang Yuan
2026-10-09 2:04 ` [PATCH bpf-next v2 1/2] selftests/bpf: Keep the bpffs of cgroup_hierarchical_stats private Qiliang Yuan
2026-10-09 2:12 ` sashiko-bot
2026-10-09 2:04 ` [PATCH bpf-next v2 2/2] selftests/bpf: Unmount the bpffs that cgroup_hierarchical_stats mounted Qiliang Yuan
2026-10-09 2:14 ` sashiko-bot [this message]
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