twx-linux/kernel/cgroup
Tim Van Patten cff5f49d43 cgroup_freezer: cgroup_freezing: Check if not frozen
__thaw_task() was recently updated to warn if the task being thawed was
part of a freezer cgroup that is still currently freezing:

	void __thaw_task(struct task_struct *p)
	{
	...
		if (WARN_ON_ONCE(freezing(p)))
			goto unlock;

This has exposed a bug in cgroup1 freezing where when CGROUP_FROZEN is
asserted, the CGROUP_FREEZING bits are not also cleared at the same
time. Meaning, when a cgroup is marked FROZEN it continues to be marked
FREEZING as well. This causes the WARNING to trigger, because
cgroup_freezing() thinks the cgroup is still freezing.

There are two ways to fix this:

1. Whenever FROZEN is set, clear FREEZING for the cgroup and all
children cgroups.
2. Update cgroup_freezing() to also verify that FROZEN is not set.

This patch implements option (2), since it's smaller and more
straightforward.

Signed-off-by: Tim Van Patten <timvp@google.com>
Tested-by: Mark Hasemeyer <markhas@chromium.org>
Fixes: f5d39b020809 ("freezer,sched: Rewrite core freezer logic")
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-11-28 08:04:03 -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 Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
cpuset.c cgroup/cpuset: Cleanup signedness issue in cpu_exclusive_check() 2023-10-04 08:58:33 -10:00
debug.c
freezer.c cgroup: cleanup comments 2022-03-13 19:19:27 -10:00
legacy_freezer.c cgroup_freezer: cgroup_freezing: Check if not frozen 2023-11-28 08:04:03 -10:00
Makefile
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 bpf: Add __bpf_hook_{start,end} macros 2023-11-01 22:33:53 -07:00