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| author | Michal Koutný <mkoutny@suse.com> | 2020-01-24 14:40:15 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-20 12:54:14 +0300 |
| commit | 713f26696c8c8f7121cabe1a5a44353ffccda06e (patch) | |
| tree | 4d33290aeb58f7e691be143fd007d6e3d3ba9f5d /include/linux/cgroup.h | |
| parent | b58120a61b256e3c24b957fe36617bdc738efc9c (diff) | |
| download | linux-713f26696c8c8f7121cabe1a5a44353ffccda06e.tar.xz | |
cgroup: Iterate tasks that did not finish do_exit()
commit 9c974c77246460fa6a92c18554c3311c8c83c160 upstream.
PF_EXITING is set earlier than actual removal from css_set when a task
is exitting. This can confuse cgroup.procs readers who see no PF_EXITING
tasks, however, rmdir is checking against css_set membership so it can
transitionally fail with EBUSY.
Fix this by listing tasks that weren't unlinked from css_set active
lists.
It may happen that other users of the task iterator (without
CSS_TASK_ITER_PROCS) spot a PF_EXITING task before cgroup_exit(). This
is equal to the state before commit c03cd7738a83 ("cgroup: Include dying
leaders with live threads in PROCS iterations") but it may be reviewed
later.
Reported-by: Suren Baghdasaryan <surenb@google.com>
Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 0e21619f1c03..61ab21c34866 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -61,6 +61,7 @@ struct css_task_iter { struct list_head *mg_tasks_head; struct list_head *dying_tasks_head; + struct list_head *cur_tasks_head; struct css_set *cur_cset; struct css_set *cur_dcset; struct task_struct *cur_task; |