From: Kirill Tkhai <ktkhai@virtuozzo.com>
To: viro@zeniv.linux.org.uk, adobriyan@gmail.com,
davem@davemloft.net, ebiederm@xmission.com,
akpm@linux-foundation.org, christian.brauner@ubuntu.com,
areber@redhat.com, serge@hallyn.com,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
ktkhai@virtuozzo.com
Subject: [PATCH 15/23] pid: Eextract child_reaper check from pidns_for_children_get()
Date: Thu, 30 Jul 2020 15:00:41 +0300 [thread overview]
Message-ID: <159611044115.535980.10236831314879436296.stgit@localhost.localdomain> (raw)
In-Reply-To: <159611007271.535980.15362304262237658692.stgit@localhost.localdomain>
This check if for prohibiting access to /proc/[pid]/ns/pid_for_children
before first task of the pid namespace is created.
/proc/namespaces/ code will use this check too, so we move it into
a separate function.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
---
kernel/pid_namespace.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index d02dc1696edf..4a01328e8763 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -343,6 +343,21 @@ static struct ns_common *pidns_get(struct task_struct *task)
return ns ? &ns->ns : NULL;
}
+static bool pidns_can_get(struct ns_common *ns)
+{
+ struct pid_namespace *pid_ns;
+ bool ret = true;
+
+ pid_ns = container_of(ns, struct pid_namespace, ns);
+
+ read_lock(&tasklist_lock);
+ if (!pid_ns->child_reaper)
+ ret = false;
+ read_unlock(&tasklist_lock);
+
+ return ret;
+}
+
static struct ns_common *pidns_for_children_get(struct task_struct *task)
{
struct pid_namespace *ns = NULL;
@@ -354,13 +369,9 @@ static struct ns_common *pidns_for_children_get(struct task_struct *task)
}
task_unlock(task);
- if (ns) {
- read_lock(&tasklist_lock);
- if (!ns->child_reaper) {
- put_pid_ns(ns);
- ns = NULL;
- }
- read_unlock(&tasklist_lock);
+ if (ns && !pidns_can_get(&ns->ns)) {
+ put_pid_ns(ns);
+ ns = NULL;
}
return ns ? &ns->ns : NULL;
next prev parent reply other threads:[~2020-07-30 12:00 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 11:59 [PATCH 00/23] proc: Introduce /proc/namespaces/ directory to expose namespaces lineary Kirill Tkhai
2020-07-30 11:59 ` [PATCH 01/23] ns: Add common refcount into ns_common add use it as counter for net_ns Kirill Tkhai
2020-07-30 13:35 ` Christian Brauner
2020-07-30 14:07 ` Kirill Tkhai
2020-07-30 15:59 ` Christian Brauner
2020-07-30 14:30 ` Christian Brauner
2020-07-30 14:34 ` Kirill Tkhai
2020-07-30 14:39 ` Christian Brauner
2020-07-30 11:59 ` [PATCH 02/23] uts: Use generic ns_common::count Kirill Tkhai
2020-07-30 14:30 ` Christian Brauner
2020-07-30 11:59 ` [PATCH 03/23] ipc: " Kirill Tkhai
2020-07-30 14:32 ` Christian Brauner
2020-07-30 11:59 ` [PATCH 04/23] pid: " Kirill Tkhai
2020-07-30 14:37 ` Christian Brauner
2020-07-30 11:59 ` [PATCH 05/23] user: " Kirill Tkhai
2020-07-30 14:46 ` Christian Brauner
2020-07-30 11:59 ` [PATCH 06/23] mnt: " Kirill Tkhai
2020-07-30 14:49 ` Christian Brauner
2020-07-30 11:59 ` [PATCH 07/23] cgroup: " Kirill Tkhai
2020-07-30 14:50 ` Christian Brauner
2020-07-30 12:00 ` [PATCH 08/23] time: " Kirill Tkhai
2020-07-30 14:52 ` Christian Brauner
2020-07-30 12:00 ` [PATCH 09/23] ns: Introduce ns_idr to be able to iterate all allocated namespaces in the system Kirill Tkhai
2020-07-30 12:23 ` Matthew Wilcox
2020-07-30 13:32 ` Kirill Tkhai
2020-07-30 13:56 ` Matthew Wilcox
2020-07-30 14:12 ` Kirill Tkhai
2020-07-30 14:15 ` Matthew Wilcox
2020-07-30 14:20 ` Kirill Tkhai
2020-07-30 12:00 ` [PATCH 10/23] fs: Rename fs/proc/namespaces.c into fs/proc/task_namespaces.c Kirill Tkhai
2020-07-30 12:00 ` [PATCH 11/23] fs: Add /proc/namespaces/ directory Kirill Tkhai
2020-07-30 12:18 ` Alexey Dobriyan
2020-07-30 13:22 ` Kirill Tkhai
2020-07-30 13:26 ` Christian Brauner
2020-07-30 14:30 ` Kirill Tkhai
2020-07-30 20:47 ` kernel test robot
2020-07-30 22:20 ` kernel test robot
2020-08-05 8:17 ` kernel test robot
2020-08-05 8:17 ` [RFC PATCH] fs: namespaces_dentry_operations can be static kernel test robot
2020-07-30 12:00 ` [PATCH 12/23] user: Free user_ns one RCU grace period after final counter put Kirill Tkhai
2020-07-30 12:00 ` [PATCH 13/23] user: Add user namespaces into ns_idr Kirill Tkhai
2020-07-30 12:00 ` [PATCH 14/23] net: Add net " Kirill Tkhai
2020-07-30 12:00 ` Kirill Tkhai [this message]
2020-07-30 12:00 ` [PATCH 16/23] proc_ns_operations: Add can_get method Kirill Tkhai
2020-07-30 12:00 ` [PATCH 17/23] pid: Add pid namespaces into ns_idr Kirill Tkhai
2020-07-30 12:00 ` [PATCH 18/23] uts: Free uts namespace one RCU grace period after final counter put Kirill Tkhai
2020-07-30 12:01 ` [PATCH 19/23] uts: Add uts namespaces into ns_idr Kirill Tkhai
2020-07-30 12:01 ` [PATCH 20/23] ipc: Add ipc " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 21/23] mnt: Add mount " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 22/23] cgroup: Add cgroup " Kirill Tkhai
2020-07-30 12:01 ` [PATCH 23/23] time: Add time " Kirill Tkhai
2020-07-30 13:08 ` [PATCH 00/23] proc: Introduce /proc/namespaces/ directory to expose namespaces lineary Christian Brauner
2020-07-30 13:38 ` Christian Brauner
2020-07-30 14:34 ` Eric W. Biederman
2020-07-30 14:42 ` Christian Brauner
2020-07-30 15:01 ` Kirill Tkhai
2020-07-30 22:13 ` Eric W. Biederman
2020-07-31 8:48 ` Pavel Tikhomirov
2020-08-03 10:03 ` Kirill Tkhai
2020-08-03 10:51 ` Alexey Dobriyan
2020-08-06 8:05 ` Andrei Vagin
2020-08-07 8:47 ` Kirill Tkhai
2020-08-10 17:34 ` Andrei Vagin
2020-08-11 10:23 ` Kirill Tkhai
2020-08-12 17:53 ` Andrei Vagin
2020-08-13 8:12 ` Kirill Tkhai
2020-08-14 1:16 ` Andrei Vagin
2020-08-14 15:11 ` Kirill Tkhai
2020-08-14 19:21 ` Andrei Vagin
2020-08-17 14:05 ` Kirill Tkhai
2020-08-17 15:48 ` Eric W. Biederman
2020-08-17 17:47 ` Christian Brauner
2020-08-17 18:53 ` Eric W. Biederman
2020-08-04 5:43 ` Andrei Vagin
2020-08-04 12:11 ` Pavel Tikhomirov
2020-08-04 14:47 ` Kirill Tkhai
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