On Fri, Jun 27, 2025 at 2:19 PM Ihor Solodrai <ihor.solodrai@xxxxxxxxx> wrote:
>
> On 6/27/25 12:12 PM, Song Liu wrote:
> > cgroup_xattr/read_cgroupfs_xattr has two issues:
> >
> > 1. cgroup_xattr/read_cgroupfs_xattr messes up lo without creating a netns
> > first. This causes issue with other tests.
> >
> > Fix this by using a different hook (lsm.s/file_open) and not messing
> > with lo.
> >
> > 2. cgroup_xattr/read_cgroupfs_xattr sets up cgroups without proper
> > mount namespaces.
> >
> > Fix this by using the existing cgroup helpers. A new helper
> > set_cgroup_xattr() is added to set xattr on cgroup files.
> >
> > Fixes: f4fba2d6d282 ("selftests/bpf: Add tests for bpf_cgroup_read_xattr")
> > Reported-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> > Closes: https://lore.kernel.org/bpf/CAADnVQ+iqMi2HEj_iH7hsx+XJAsqaMWqSDe4tzcGAnehFWA9Sw@xxxxxxxxxxxxxx/
> > Signed-off-by: Song Liu <song@xxxxxxxxxx>
> >
> > ---
> > Changes v1 => v2:
> > 1. Add the second fix above.
> >
> > v1: https://lore.kernel.org/bpf/20250627165831.2979022-1-song@xxxxxxxxxx/
> > ---
> > tools/testing/selftests/bpf/cgroup_helpers.c | 21 ++++
> > tools/testing/selftests/bpf/cgroup_helpers.h | 4 +
> > .../selftests/bpf/prog_tests/cgroup_xattr.c | 117 ++++--------------
> > .../selftests/bpf/progs/read_cgroupfs_xattr.c | 4 +-
> > 4 files changed, 49 insertions(+), 97 deletions(-)
>
> Hi Song.
>
> I tried this patch on BPF CI, and it appears it fixes the hanging
> failure we've been seeing today on bpf-next and netdev.
> I am going to add it to ci/diffs.
Applied to bpf-next already.
