blob: f1ed2fe76c6575b9fc7ad28fdc215f87e6a73b3e [file] [log] [blame]
/* Function to determine if a thread group is single threaded or not
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (
* - Derived from security/selinux/hooks.c
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
#include <linux/sched.h>
* is_single_threaded - Determine if a thread group is single-threaded or not
* @p: A task in the thread group in question
* This returns true if the thread group to which a task belongs is single
* threaded, false if it is not.
bool is_single_threaded(struct task_struct *p)
struct task_struct *g, *t;
struct mm_struct *mm = p->mm;
if (atomic_read(&p->signal->count) != 1)
goto no;
if (atomic_read(&p->mm->mm_users) != 1) {
do_each_thread(g, t) {
if (t->mm == mm && t != p)
goto no_unlock;
} while_each_thread(g, t);
return true;
return false;