From: Tang Yizhou <tangyizhou@huawei.com> ascend inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4EUVI CVE: NA ------------------------------------------------- The procedure of finding task_struct and increasing its refcount is duplicate. Extract function get_task to eliminate redundant code. Signed-off-by: Tang Yizhou <tangyizhou@huawei.com> Reviewed-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com> Reviewed-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- mm/share_pool.c | 36 ++++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/mm/share_pool.c b/mm/share_pool.c index 4dde5f8582cb8..1cc2d3eba264e 100644 --- a/mm/share_pool.c +++ b/mm/share_pool.c @@ -729,6 +729,24 @@ static void sp_group_drop(struct sp_group *spg) free_sp_group(spg); } +/* use with put_task_struct(task) */ +static int get_task(int pid, struct task_struct **task) +{ + struct task_struct *tsk; + + rcu_read_lock(); + tsk = find_task_by_vpid(pid); + if (!tsk || (tsk->flags & PF_EXITING)) { + rcu_read_unlock(); + return -ESRCH; + } + get_task_struct(tsk); + rcu_read_unlock(); + + *task = tsk; + return 0; +} + static struct sp_group *get_first_group(struct mm_struct *mm) { struct sp_group *spg = NULL; @@ -757,13 +775,7 @@ static struct sp_group *__sp_find_spg_locked(int pid, int spg_id) int ret = 0; if (spg_id == SPG_ID_DEFAULT) { - rcu_read_lock(); - tsk = find_task_by_vpid(pid); - if (!tsk || (tsk->flags & PF_EXITING)) - ret = -ESRCH; - else - get_task_struct(tsk); - rcu_read_unlock(); + ret = get_task(pid, &tsk); if (ret) return NULL; @@ -1121,15 +1133,7 @@ int sp_group_add_task(int pid, unsigned long prot, int spg_id) down_write(&sp_group_sem); - rcu_read_lock(); - - tsk = find_task_by_vpid(pid); - if (!tsk || (tsk->flags & PF_EXITING)) - ret = -ESRCH; - else - get_task_struct(tsk); - - rcu_read_unlock(); + ret = get_task(pid, &tsk); if (ret) { up_write(&sp_group_sem); free_new_spg_id(id_newly_generated, spg_id); -- 2.25.1