diff options
| author | Waiman Long <longman@redhat.com> | 2023-03-17 11:15:05 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2023-03-29 08:37:07 -1000 |
| commit | 292fd843de26c551856e66faf134512c52dd78b4 (patch) | |
| tree | c64dd23e8acc0f98aef4bf91310c321ec18390ee /kernel/cgroup | |
| parent | fcdb1eda5302599045bb366e679cccb4216f3873 (diff) | |
| download | linux-292fd843de26c551856e66faf134512c52dd78b4.tar.gz | |
cgroup/cpuset: Fix partition root's cpuset.cpus update bug
It was found that commit 7a2127e66a00 ("cpuset: Call
set_cpus_allowed_ptr() with appropriate mask for task") introduced a bug
that corrupted "cpuset.cpus" of a partition root when it was updated.
It is because the tmp->new_cpus field of the passed tmp parameter
of update_parent_subparts_cpumask() should not be used at all as
it contains important cpumask data that should not be overwritten.
Fix it by using tmp->addmask instead.
Also update update_cpumask() to make sure that trialcs->cpu_allowed
will not be corrupted until it is no longer needed.
Fixes: 7a2127e66a00 ("cpuset: Call set_cpus_allowed_ptr() with appropriate mask for task")
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: stable@vger.kernel.org # v6.2+
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cpuset.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 636f1c682ac07..f310915d12575 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1513,7 +1513,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cs, int cmd, spin_unlock_irq(&callback_lock); if (adding || deleting) - update_tasks_cpumask(parent, tmp->new_cpus); + update_tasks_cpumask(parent, tmp->addmask); /* * Set or clear CS_SCHED_LOAD_BALANCE when partcmd_update, if necessary. @@ -1770,10 +1770,13 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, /* * Use the cpumasks in trialcs for tmpmasks when they are pointers * to allocated cpumasks. + * + * Note that update_parent_subparts_cpumask() uses only addmask & + * delmask, but not new_cpus. */ tmp.addmask = trialcs->subparts_cpus; tmp.delmask = trialcs->effective_cpus; - tmp.new_cpus = trialcs->cpus_allowed; + tmp.new_cpus = NULL; #endif retval = validate_change(cs, trialcs); @@ -1838,6 +1841,11 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, } spin_unlock_irq(&callback_lock); +#ifdef CONFIG_CPUMASK_OFFSTACK + /* Now trialcs->cpus_allowed is available */ + tmp.new_cpus = trialcs->cpus_allowed; +#endif + /* effective_cpus will be updated here */ update_cpumasks_hier(cs, &tmp, false); |