1 files changed, 28 insertions, 22 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 32c58f7433a..5d30019ff95 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -115,32 +115,33 @@ static void __exit_signal(struct task_struct *tsk)
 
 		if (tsk == sig->curr_target)
 			sig->curr_target = next_thread(tsk);
-		/*
-		 * Accumulate here the counters for all threads but the
-		 * group leader as they die, so they can be added into
-		 * the process-wide totals when those are taken.
-		 * The group leader stays around as a zombie as long
-		 * as there are other threads.  When it gets reaped,
-		 * the exit.c code will add its counts into these totals.
-		 * We won't ever get here for the group leader, since it
-		 * will have been the last reference on the signal_struct.
-		 */
-		task_cputime(tsk, &utime, &stime);
-		sig->utime += utime;
-		sig->stime += stime;
-		sig->gtime += task_gtime(tsk);
-		sig->min_flt += tsk->min_flt;
-		sig->maj_flt += tsk->maj_flt;
-		sig->nvcsw += tsk->nvcsw;
-		sig->nivcsw += tsk->nivcsw;
-		sig->inblock += task_io_get_inblock(tsk);
-		sig->oublock += task_io_get_oublock(tsk);
-		task_io_accounting_add(&sig->ioac, &tsk->ioac);
-		sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
 	}
 
+	/*
+	 * Accumulate here the counters for all threads but the group leader
+	 * as they die, so they can be added into the process-wide totals
+	 * when those are taken.  The group leader stays around as a zombie as
+	 * long as there are other threads.  When it gets reaped, the exit.c
+	 * code will add its counts into these totals.  We won't ever get here
+	 * for the group leader, since it will have been the last reference on
+	 * the signal_struct.
+	 */
+	task_cputime(tsk, &utime, &stime);
+	write_seqlock(&sig->stats_lock);
+	sig->utime += utime;
+	sig->stime += stime;
+	sig->gtime += task_gtime(tsk);
+	sig->min_flt += tsk->min_flt;
+	sig->maj_flt += tsk->maj_flt;
+	sig->nvcsw += tsk->nvcsw;
+	sig->nivcsw += tsk->nivcsw;
+	sig->inblock += task_io_get_inblock(tsk);
+	sig->oublock += task_io_get_oublock(tsk);
+	task_io_accounting_add(&sig->ioac, &tsk->ioac);
+	sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
 	sig->nr_threads--;
 	__unhash_process(tsk, group_dead);
+	write_sequnlock(&sig->stats_lock);
 
 	/*
 	 * Do this under ->siglock, we can race with another thread
@@ -667,6 +668,7 @@ void do_exit(long code)
 {
 	struct task_struct *tsk = current;
 	int group_dead;
+	TASKS_RCU(int tasks_rcu_i);
 
 	profile_task_exit(tsk);
 
@@ -775,6 +777,7 @@ void do_exit(long code)
 	 */
 	flush_ptrace_hw_breakpoint(tsk);
 
+	TASKS_RCU(tasks_rcu_i = __srcu_read_lock(&tasks_rcu_exit_srcu));
 	exit_notify(tsk, group_dead);
 	proc_exit_connector(tsk);
 #ifdef CONFIG_NUMA
@@ -814,6 +817,7 @@ void do_exit(long code)
 	if (tsk->nr_dirtied)
 		__this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
 	exit_rcu();
+	TASKS_RCU(__srcu_read_unlock(&tasks_rcu_exit_srcu, tasks_rcu_i));
 
 	/*
 	 * The setting of TASK_RUNNING by try_to_wake_up() may be delayed
@@ -1043,6 +1047,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 		spin_lock_irq(&p->real_parent->sighand->siglock);
 		psig = p->real_parent->signal;
 		sig = p->signal;
+		write_seqlock(&psig->stats_lock);
 		psig->cutime += tgutime + sig->cutime;
 		psig->cstime += tgstime + sig->cstime;
 		psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime;
@@ -1065,6 +1070,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 			psig->cmaxrss = maxrss;
 		task_io_accounting_add(&psig->ioac, &p->ioac);
 		task_io_accounting_add(&psig->ioac, &sig->ioac);
+		write_sequnlock(&psig->stats_lock);
 		spin_unlock_irq(&p->real_parent->sighand->siglock);
 	}