Merge tag 'cgroup-for-6.0-rc2-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull another cgroup fix from Tejun Heo:
 "Commit 4f7e723643 ("cgroup: Fix threadgroup_rwsem <->
  cpus_read_lock() deadlock") required the cgroup
  core to grab cpus_read_lock() before invoking ->attach().

  Unfortunately, it missed adding cpus_read_lock() in
  cgroup_attach_task_all(). Fix it"

* tag 'cgroup-for-6.0-rc2-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Add missing cpus_read_lock() to cgroup_attach_task_all()
This commit is contained in:
Linus Torvalds
2022-08-25 10:52:16 -07:00

View File

@@ -59,6 +59,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
int retval = 0;
mutex_lock(&cgroup_mutex);
cpus_read_lock();
percpu_down_write(&cgroup_threadgroup_rwsem);
for_each_root(root) {
struct cgroup *from_cgrp;
@@ -72,6 +73,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
break;
}
percpu_up_write(&cgroup_threadgroup_rwsem);
cpus_read_unlock();
mutex_unlock(&cgroup_mutex);
return retval;