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: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2008-02-08 04:19:19 -08:00 committed by Linus Torvalds
parent 46f382d2b6
commit fea9d17554
5 changed files with 5 additions and 38 deletions

View File

@ -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);

View File

@ -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);

View File

@ -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));

View File

@ -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;
}

View File

@ -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)
{