do_notify_parent_cldstop

/**

* do_notify_parent_cldstop - notify parent of stopped/continued state change

* @tsk: task reporting the state change

* @for_ptracer: the notification is for ptracer

* @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report

*

* Notify @tsk's parent that the stopped/continued state has changed. If

* @for_ptracer is %false, @tsk's group leader notifies to its real parent.

* If %true, @tsk reports to @tsk->parent which should be the ptracer.

*

* CONTEXT:

* Must be called with tasklist_lock at least read locked.

*/

static void do_notify_parent_cldstop(struct task_struct *tsk,

bool for_ptracer, int why)

{

struct kernel_siginfo info;

unsigned long flags;

struct task_struct *parent;

struct sighand_struct *sighand;

u64 utime, stime;

if (for_ptracer) {

parent = tsk->parent;

} else {

tsk = tsk->group_leader;

parent = tsk->real_parent;

}

clear_siginfo(&info);

info.si_signo = SIGCHLD;

info.si_errno = 0;

/*

* see comment in do_notify_parent() about the following 4 lines

*/

rcu_read_lock();

info.si_pid = task_pid_nr_ns(tsk, task_active_pid_ns(parent));

info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));

rcu_read_unlock();

task_cputime(tsk, &utime, &stime);

info.si_utime = nsec_to_clock_t(utime);

info.si_stime = nsec_to_clock_t(stime);

info.si_code = why;

switch (why) {

case CLD_CONTINUED:

info.si_status = SIGCONT;

break;

case CLD_STOPPED:

info.si_status = tsk->signal->group_exit_code & 0x7f;

break;

case CLD_TRAPPED:

info.si_status = tsk->exit_code & 0x7f;

break;

default:

BUG();

}

sighand = parent->sighand;

spin_lock_irqsave(&sighand->siglock, flags);

if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN &&

!(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP))

send_signal_locked(SIGCHLD, &info, parent, PIDTYPE_TGID);

/*

* Even if SIGCHLD is not generated, we must wake up wait4 calls.

*/

__wake_up_parent(tsk, parent);

spin_unlock_irqrestore(&sighand->siglock, flags);

}