/* 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 (dhowells@redhat.com) * - 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> /* * Returns true if the task does not share ->mm with another thread/process. */
bool current_is_single_threaded(void) { struct task_struct *task = current; struct mm_struct *mm = task->mm; struct task_struct *p, *t; bool ret; if (atomic_read(&task->signal->live) != 1) return false; if (atomic_read(&mm->mm_users) == 1) return true; ret = false; rcu_read_lock(); for_each_process(p) { if (unlikely(p->flags & PF_KTHREAD)) continue; if (unlikely(p == task->group_leader)) continue; for_each_thread(p, t) { if (unlikely(t->mm == mm)) goto found; if (likely(t->mm)) break; /* * t->mm == NULL. Make sure next_thread/next_task * will see other CLONE_VM tasks which might be * forked before exiting. */ smp_rmb(); } } ret = true; found: rcu_read_unlock(); return ret; }Contributors
Person | Tokens | Prop | Commits | CommitProp | |
oleg nesterov | oleg nesterov | 94 | 62.25% | 4 | 80.00% |
david howells | david howells | 57 | 37.75% | 1 | 20.00% |
Total | 151 | 100.00% | 5 | 100.00% |
Person | Tokens | Prop | Commits | CommitProp | |
oleg nesterov | oleg nesterov | 95 | 60.90% | 4 | 80.00% |
david howells | david howells | 61 | 39.10% | 1 | 20.00% |
Total | 156 | 100.00% | 5 | 100.00% |