diff options
| author | Waiman Long <longman@redhat.com> | 2023-03-17 18:15:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-04-20 13:35:13 +0300 |
| commit | f06c9b01540c3bf7340d8bb80ce852056933006a (patch) | |
| tree | 4b20b8ffb02cb60d886cb8f4e9cd95756ea6b03e /kernel/cgroup | |
| parent | 53244494bfcb9612b660f84c8c4f9b2282a766cd (diff) | |
| download | linux-f06c9b01540c3bf7340d8bb80ce852056933006a.tar.xz | |
cgroup/cpuset: Fix partition root's cpuset.cpus update bug
commit 292fd843de26c551856e66faf134512c52dd78b4 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 fac426036620..3f23b747cc1e 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1509,7 +1509,7 @@ 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. @@ -1766,10 +1766,13 @@ 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); @@ -1834,6 +1837,11 @@ 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); |