Commit fea9d175 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

ITIMER_REAL: convert to use struct pid 



signal_struct->tsk points to the ->group_leader and thus we have the nasty
code in de_thread() which has to change it and restart ->real_timer if the
leader is changed.

Use "struct pid *leader_pid" instead.  This also allows us to kill now
unneeded send_group_sig_info().

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Acked-by: default avatarRoland McGrath <roland@redhat.com>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 46f382d2

fs/exec.c

+2 −20
Original line number Diff line number Diff line
@@ -782,26 +782,8 @@ static int de_thread(struct task_struct *tsk) 
	zap_other_threads(tsk);

	read_unlock(&tasklist_lock);



	/*

	 * Account for the thread group leader hanging around:

	 */

	count = 1;

	if (!thread_group_leader(tsk)) {

		count = 2;

		/*

		 * The SIGALRM timer survives the exec, but needs to point

		 * at us as the new group leader now.  We have a race with

		 * a timer firing now getting the old leader, so we need to

		 * synchronize with any firing (by calling del_timer_sync)

		 * before we can safely let the old group leader die.

		 */

		sig->tsk = tsk;

		spin_unlock_irq(lock);

		if (hrtimer_cancel(&sig->real_timer))

			hrtimer_restart(&sig->real_timer);

		spin_lock_irq(lock);

	}



	/* Account for the thread group leader hanging around: */

	count = thread_group_leader(tsk) ? 1 : 2;

	sig->notify_count = count;

	while (atomic_read(&sig->count) > count) {

		__set_current_state(TASK_UNINTERRUPTIBLE);

include/linux/sched.h

+1 −2
Original line number Diff line number Diff line
@@ -460,7 +460,7 @@ struct signal_struct { 


	/* ITIMER_REAL timer for the process */

	struct hrtimer real_timer;

	struct task_struct *tsk;

	struct pid *leader_pid;

	ktime_t it_real_incr;



	/* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
@@ -1686,7 +1686,6 @@ extern void block_all_signals(int (*notifier)(void *priv), void *priv, 
extern void unblock_all_signals(void);

extern void release_task(struct task_struct * p);

extern int send_sig_info(int, struct siginfo *, struct task_struct *);

extern int send_group_sig_info(int, struct siginfo *, struct task_struct *);

extern int force_sigsegv(int, struct task_struct *);

extern int force_sig_info(int, struct siginfo *, struct task_struct *);

extern int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp);

kernel/fork.c

+1 −1
Original line number Diff line number Diff line
@@ -909,7 +909,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) 
	hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

	sig->it_real_incr.tv64 = 0;

	sig->real_timer.function = it_real_fn;

	sig->tsk = tsk;



	sig->it_virt_expires = cputime_zero;

	sig->it_virt_incr = cputime_zero;
@@ -1338,6 +1337,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, 
			if (clone_flags & CLONE_NEWPID)

				p->nsproxy->pid_ns->child_reaper = p;



			p->signal->leader_pid = pid;

			p->signal->tty = current->signal->tty;

			set_task_pgrp(p, task_pgrp_nr(current));

			set_task_session(p, task_session_nr(current));

kernel/itimer.c

+1 −1
Original line number Diff line number Diff line
@@ -132,7 +132,7 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) 
	struct signal_struct *sig =

		container_of(timer, struct signal_struct, real_timer);



	send_group_sig_info(SIGALRM, SEND_SIG_PRIV, sig->tsk);

	kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid);



	return HRTIMER_NORESTART;

}

kernel/signal.c

+0 −14
Original line number Diff line number Diff line
@@ -1205,20 +1205,6 @@ send_sig(int sig, struct task_struct *p, int priv) 
	return send_sig_info(sig, __si_special(priv), p);

}



/*

 * This is the entry point for "process-wide" signals.

 * They will go to an appropriate thread in the thread group.

 */

int

send_group_sig_info(int sig, struct siginfo *info, struct task_struct *p)

{

	int ret;

	read_lock(&tasklist_lock);

	ret = group_send_sig_info(sig, info, p);

	read_unlock(&tasklist_lock);

	return ret;

}



void

force_sig(int sig, struct task_struct *p)

{

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