Messages in this thread | | | Date | Tue, 7 Sep 2021 07:01:06 -1000 | From | Tejun Heo <> | Subject | Re: [PATCH] kernel/sched: Fix sched_fork() access an invalid sched_task_group |
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Hello,
On Thu, Sep 02, 2021 at 03:42:15PM +0800, Zhang Qiao wrote: > I checked the code again. > I don't quite understand what you said, if the child be moved between > cgroup_post_fork() and sched_post_sched(), what problems might it cause?
cgroup_post_fork() is where the child's creation is committed from cgroup's POV, so it'd be migrating cgroups before the initial creation is finished. From glancing, looks like it'll break css_set task counts to begin with. This violates the basic assumptions and can cause critical failures in subtle ways. The would replace one subtle race with a possibly worse one.
Thanks.
-- tejun
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