Commit b0101ccb authored by Liang Jie's avatar Liang Jie Committed by Tejun Heo
Browse files

sched_ext: fix uninitialized ret on alloc_percpu() failure 



Smatch reported:

  kernel/sched/ext.c:5332 scx_alloc_and_add_sched() warn: passing zero to 'ERR_PTR'

In scx_alloc_and_add_sched(), the alloc_percpu() failure path jumps to
err_free_gdsqs without initializing @ret. That can lead to returning
ERR_PTR(0), which violates the ERR_PTR() convention and confuses
callers.

Set @ret to -ENOMEM before jumping to the error path when
alloc_percpu() fails.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202512141601.yAXDAeA9-lkp@intel.com/


Reported-by: default avatarDan Carpenter <error27@gmail.com>
Fixes: c201ea15 ("sched_ext: Move event_stats_cpu into scx_sched")
Signed-off-by: default avatarLiang Jie <liangjie@lixiang.com>
Reviewed-by: default avatarEmil Tsalapatis <emil@etsalapatis.com>
Reviewed-by: default avatarAndrea Righi <arighi@nvidia.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent bb27226f

kernel/sched/ext.c

+3 −1
Original line number Diff line number Diff line
@@ -4783,8 +4783,10 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops) 
	}



	sch->pcpu = alloc_percpu(struct scx_sched_pcpu);

	if (!sch->pcpu)

	if (!sch->pcpu) {

		ret = -ENOMEM;

		goto err_free_gdsqs;

	}



	sch->helper = kthread_run_worker(0, "sched_ext_helper");

	if (IS_ERR(sch->helper)) {