Merge tag 'cgroup-for-7.0-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:

 - Fix circular locking dependency in cpuset partition code by
   deferring housekeeping_update() calls to a workqueue instead
   of calling them directly under cpus_read_lock

 - Fix null-ptr-deref in rebuild_sched_domains_cpuslocked() when
   generate_sched_domains() returns NULL due to kmalloc failure

 - Fix incorrect cpuset behavior for effective_xcpus in
   partition_xcpus_del() and cpuset_update_tasks_cpumask()
   in update_cpumasks_hier()

 - Fix race between task migration and cgroup iteration

* tag 'cgroup-for-7.0-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: fix null-ptr-deref in rebuild_sched_domains_cpuslocked
  cgroup/cpuset: Call housekeeping_update() without holding cpus_read_lock
  cgroup/cpuset: Defer housekeeping_update() calls from CPU hotplug to workqueue
  cgroup/cpuset: Move housekeeping_update()/rebuild_sched_domains() together
  kselftest/cgroup: Simplify test_cpuset_prs.sh by removing "S+" command
  cgroup/cpuset: Set isolated_cpus_updating only if isolated_cpus is changed
  cgroup/cpuset: Clarify exclusion rules for cpuset internal variables
  cgroup/cpuset: Fix incorrect use of cpuset_update_tasks_cpumask() in update_cpumasks_hier()
  cgroup/cpuset: Fix incorrect change to effective_xcpus in partition_xcpus_del()
  cgroup: fix race between task migration and iteration

1 files changed, 1 insertions, 3 deletions

diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c
index c1ed0d5e8de6..155eeaea4113 100644
--- a/kernel/time/timer_migration.c
+++ b/kernel/time/timer_migration.c
@@ -1559,8 +1559,6 @@ int tmigr_isolated_exclude_cpumask(struct cpumask *exclude_cpumask)
 	cpumask_var_t cpumask __free(free_cpumask_var) = CPUMASK_VAR_NULL;
 	int cpu;
 
-	lockdep_assert_cpus_held();
-
 	if (!works)
 		return -ENOMEM;
 	if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
@@ -1570,6 +1568,7 @@ int tmigr_isolated_exclude_cpumask(struct cpumask *exclude_cpumask)
 	 * First set previously isolated CPUs as available (unisolate).
 	 * This cpumask contains only CPUs that switched to available now.
 	 */
+	guard(cpus_read_lock)();
 	cpumask_andnot(cpumask, cpu_online_mask, exclude_cpumask);
 	cpumask_andnot(cpumask, cpumask, tmigr_available_cpumask);
 
@@ -1626,7 +1625,6 @@ static int __init tmigr_init_isolation(void)
 	cpumask_andnot(cpumask, cpu_possible_mask, housekeeping_cpumask(HK_TYPE_DOMAIN));
 
 	/* Protect against RCU torture hotplug testing */
-	guard(cpus_read_lock)();
 	return tmigr_isolated_exclude_cpumask(cpumask);
 }
 late_initcall(tmigr_init_isolation);