diff options
Diffstat (limited to 'include/linux/sched/signal.h')
| -rw-r--r-- | include/linux/sched/signal.h | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index b95a272c1ab5..2dcded16eb1e 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -146,7 +146,9 @@ struct signal_struct { #endif + /* PID/PID hash table linkage. */ struct pid *leader_pid; + struct pid *pids[PIDTYPE_MAX]; #ifdef CONFIG_NO_HZ_FULL atomic_t tick_dep_mask; @@ -559,9 +561,12 @@ void walk_process_tree(struct task_struct *top, proc_visitor, void *); static inline struct pid *task_pid_type(struct task_struct *task, enum pid_type type) { - if (type != PIDTYPE_PID) - task = task->group_leader; - return task->pids[type].pid; + struct pid *pid; + if (type == PIDTYPE_PID) + pid = task_pid(task); + else + pid = task->signal->pids[type]; + return pid; } static inline struct pid *task_tgid(struct task_struct *task) @@ -569,6 +574,21 @@ static inline struct pid *task_tgid(struct task_struct *task) return task->signal->leader_pid; } +/* + * Without tasklist or RCU lock it is not safe to dereference + * the result of task_pgrp/task_session even if task == current, + * we can race with another thread doing sys_setsid/sys_setpgid. + */ +static inline struct pid *task_pgrp(struct task_struct *task) +{ + return task->signal->pids[PIDTYPE_PGID]; +} + +static inline struct pid *task_session(struct task_struct *task) +{ + return task->signal->pids[PIDTYPE_SID]; +} + static inline int get_nr_threads(struct task_struct *tsk) { return tsk->signal->nr_threads; |