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| author | Yafang Shao <laoar.shao@gmail.com> | 2023-10-29 06:14:31 +0000 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2023-11-09 13:25:47 -1000 |
| commit | 0008454e8fd30ed0017a9a35b8dd708f168931b8 (patch) | |
| tree | e1b0837749fe5823497f5206df8ebac983d1fe0d /tools/testing/selftests/bpf/prog_tests/async_stack_depth.c | |
| parent | 9067d90006df089b9a1da0d74f0cad232a5d726a (diff) | |
cgroup: Add annotation for holding namespace_sem in current_cgns_cgroup_from_root()
When I initially examined the function current_cgns_cgroup_from_root(), I
was perplexed by its lack of holding cgroup_mutex. However, after Michal
explained the reason[0] to me, I realized that it already holds the
namespace_sem. I believe this intricacy could also confuse others, so it
would be advisable to include an annotation for clarification.
After we replace the cgroup_mutex with RCU read lock, if current doesn't
hold the namespace_sem, the root cgroup will be NULL. So let's add a
WARN_ON_ONCE() for it.
[0]. https://lore.kernel.org/bpf/afdnpo3jz2ic2ampud7swd6so5carkilts2mkygcaw67vbw6yh@5b5mncf7qyet
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Michal Koutny <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/async_stack_depth.c')
0 files changed, 0 insertions, 0 deletions