linux-stable/kernel/cgroup
Michal Koutný 1ca0b60515 cgroup: Remove duplicates in cgroup v1 tasks file
One PID may appear multiple times in a preloaded pidlist.
(Possibly due to PID recycling but we have reports of the same
task_struct appearing with different PIDs, thus possibly involving
transfer of PID via de_thread().)

Because v1 seq_file iterator uses PIDs as position, it leads to
a message:
> seq_file: buggy .next function kernfs_seq_next did not update position index

Conservative and quick fix consists of removing duplicates from `tasks`
file (as opposed to removing pidlists altogether). It doesn't affect
correctness (it's sufficient to show a PID once), performance impact
would be hidden by unconditional sorting of the pidlist already in place
(asymptotically).

Link: https://lore.kernel.org/r/20230823174804.23632-1-mkoutny@suse.com/
Suggested-by: Firo Yang <firo.yang@suse.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
2023-10-09 06:42:05 -10:00
..
cgroup-internal.h cgroup: make cgroup_is_threaded() and cgroup_is_thread_root() static 2023-06-05 10:31:41 -10:00
cgroup-v1.c cgroup: Remove duplicates in cgroup v1 tasks file 2023-10-09 06:42:05 -10:00
cgroup.c cgroup: fix build when CGROUP_SCHED is not enabled 2023-09-02 08:27:17 -07:00
cpuset.c cgroup/cpuset: fix kernel-doc 2023-08-02 09:37:03 -10:00
debug.c kernel: cgroup: fix misuse of %x 2019-05-06 08:47:48 -07:00
freezer.c cgroup: cleanup comments 2022-03-13 19:19:27 -10:00
legacy_freezer.c cgroup,freezer: hold cpu_hotplug_lock before freezer_mutex in freezer_css_{online,offline}() 2023-06-12 06:39:48 -10:00
Makefile cgroup: Add misc cgroup controller 2021-04-04 13:34:46 -04:00
misc.c cgroup/misc: Store atomic64_t reads to u64 2023-07-21 08:10:06 -10:00
namespace.c cgroup:namespace: Remove unused cgroup_namespaces_init() 2023-08-14 14:29:47 -10:00
pids.c cgroup: add pids.peak interface for pids controller 2022-09-04 09:26:51 -10:00
rdma.c rdmacg: fix kernel-doc warnings in rdmacg 2023-06-05 09:45:14 -10:00
rstat.c cgroup/rstat: Record the cumulative per-cpu time of cgroup and its descendants 2023-08-07 08:41:25 -10:00