mirror of
https://github.com/Fishwaldo/Star64_linux.git
synced 2025-03-16 12:14:06 +00:00
sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed
[ Upstream commitb6e8d40d43
] With cgroup v2, the cpuset's cpus_allowed mask can be empty indicating that the cpuset will just use the effective CPUs of its parent. So cpuset_can_attach() can call task_can_attach() with an empty mask. This can lead to cpumask_any_and() returns nr_cpu_ids causing the call to dl_bw_of() to crash due to percpu value access of an out of bound CPU value. For example: [80468.182258] BUG: unable to handle page fault for address: ffffffff8b6648b0 : [80468.191019] RIP: 0010:dl_cpu_busy+0x30/0x2b0 : [80468.207946] Call Trace: [80468.208947] cpuset_can_attach+0xa0/0x140 [80468.209953] cgroup_migrate_execute+0x8c/0x490 [80468.210931] cgroup_update_dfl_csses+0x254/0x270 [80468.211898] cgroup_subtree_control_write+0x322/0x400 [80468.212854] kernfs_fop_write_iter+0x11c/0x1b0 [80468.213777] new_sync_write+0x11f/0x1b0 [80468.214689] vfs_write+0x1eb/0x280 [80468.215592] ksys_write+0x5f/0xe0 [80468.216463] do_syscall_64+0x5c/0x80 [80468.224287] entry_SYSCALL_64_after_hwframe+0x44/0xae Fix that by using effective_cpus instead. For cgroup v1, effective_cpus is the same as cpus_allowed. For v2, effective_cpus is the real cpumask to be used by tasks within the cpuset anyway. Also update task_can_attach()'s 2nd argument name to cs_effective_cpus to reflect the change. In addition, a check is added to task_can_attach() to guard against the possibility that cpumask_any_and() may return a value >= nr_cpu_ids. Fixes:7f51412a41
("sched/deadline: Fix bandwidth check/update when migrating tasks between exclusive cpusets") Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20220803015451.2219567-1-longman@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
parent
206faaec47
commit
3cb5953071
3 changed files with 7 additions and 5 deletions
|
@ -1797,7 +1797,7 @@ current_restore_flags(unsigned long orig_flags, unsigned long flags)
|
|||
}
|
||||
|
||||
extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
|
||||
extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
|
||||
extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus);
|
||||
#ifdef CONFIG_SMP
|
||||
extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
|
||||
extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
|
||||
|
|
|
@ -2199,7 +2199,7 @@ static int cpuset_can_attach(struct cgroup_taskset *tset)
|
|||
goto out_unlock;
|
||||
|
||||
cgroup_taskset_for_each(task, css, tset) {
|
||||
ret = task_can_attach(task, cs->cpus_allowed);
|
||||
ret = task_can_attach(task, cs->effective_cpus);
|
||||
if (ret)
|
||||
goto out_unlock;
|
||||
ret = security_task_setscheduler(task);
|
||||
|
|
|
@ -8741,7 +8741,7 @@ int cpuset_cpumask_can_shrink(const struct cpumask *cur,
|
|||
}
|
||||
|
||||
int task_can_attach(struct task_struct *p,
|
||||
const struct cpumask *cs_cpus_allowed)
|
||||
const struct cpumask *cs_effective_cpus)
|
||||
{
|
||||
int ret = 0;
|
||||
|
||||
|
@ -8760,9 +8760,11 @@ int task_can_attach(struct task_struct *p,
|
|||
}
|
||||
|
||||
if (dl_task(p) && !cpumask_intersects(task_rq(p)->rd->span,
|
||||
cs_cpus_allowed)) {
|
||||
int cpu = cpumask_any_and(cpu_active_mask, cs_cpus_allowed);
|
||||
cs_effective_cpus)) {
|
||||
int cpu = cpumask_any_and(cpu_active_mask, cs_effective_cpus);
|
||||
|
||||
if (unlikely(cpu >= nr_cpu_ids))
|
||||
return -EINVAL;
|
||||
ret = dl_cpu_busy(cpu, p);
|
||||
}
|
||||
|
||||
|
|
Loading…
Add table
Reference in a new issue