Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754173AbaDXIyA (ORCPT ); Thu, 24 Apr 2014 04:54:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:46642 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754088AbaDXIx4 (ORCPT ); Thu, 24 Apr 2014 04:53:56 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Eric W. Biederman" , Richard Guy Briggs , Luis Henriques Subject: [PATCH 3.11 083/182] pid: get pid_t ppid of task in init_pid_ns Date: Thu, 24 Apr 2014 09:50:08 +0100 Message-Id: <1398329507-5911-84-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1398329507-5911-1-git-send-email-luis.henriques@canonical.com> References: <1398329507-5911-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Richard Guy Briggs commit ad36d28293936b03d6b7996e9d6aadfd73c0eb08 upstream. Added the functions task_ppid_nr_ns() and task_ppid_nr() to abstract the lookup of the PPID (real_parent's pid_t) of a process, including rcu locking, in the arbitrary and init_pid_ns. This provides an alternative to sys_getppid(), which is relative to the child process' pid namespace. (informed by ebiederman's 6c621b7e) Cc: Eric W. Biederman Signed-off-by: Richard Guy Briggs Signed-off-by: Luis Henriques --- include/linux/sched.h | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index e057ea0..f184046 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1500,6 +1500,24 @@ static inline pid_t task_tgid_vnr(struct task_struct *tsk) } +static int pid_alive(const struct task_struct *p); +static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns) +{ + pid_t pid = 0; + + rcu_read_lock(); + if (pid_alive(tsk)) + pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns); + rcu_read_unlock(); + + return pid; +} + +static inline pid_t task_ppid_nr(const struct task_struct *tsk) +{ + return task_ppid_nr_ns(tsk, &init_pid_ns); +} + static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) { @@ -1539,7 +1557,7 @@ static inline pid_t task_pgrp_nr(struct task_struct *tsk) * * Return: 1 if the process is alive. 0 otherwise. */ -static inline int pid_alive(struct task_struct *p) +static inline int pid_alive(const struct task_struct *p) { return p->pids[PIDTYPE_PID].pid != NULL; } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/