mirror of
https://github.com/torvalds/linux.git
synced 2024-11-27 14:41:39 +00:00
45531757b4
The ns_cgroup will be removed very soon. Let's warn, for this version, ns_cgroup is deprecated. Make ns_cgroup and clone_children exclusive. If the clone_children is set and the ns_cgroup is mounted, let's fail with EINVAL when the ns_cgroup subsys is created (a printk will help the user to understand why the creation fails). Update the feature remove schedule file with the deprecated ns_cgroup. Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
/*
|
|
* ns_cgroup.c - namespace cgroup subsystem
|
|
*
|
|
* Copyright 2006, 2007 IBM Corp
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/cgroup.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/nsproxy.h>
|
|
|
|
struct ns_cgroup {
|
|
struct cgroup_subsys_state css;
|
|
};
|
|
|
|
struct cgroup_subsys ns_subsys;
|
|
|
|
static inline struct ns_cgroup *cgroup_to_ns(
|
|
struct cgroup *cgroup)
|
|
{
|
|
return container_of(cgroup_subsys_state(cgroup, ns_subsys_id),
|
|
struct ns_cgroup, css);
|
|
}
|
|
|
|
int ns_cgroup_clone(struct task_struct *task, struct pid *pid)
|
|
{
|
|
char name[PROC_NUMBUF];
|
|
|
|
snprintf(name, PROC_NUMBUF, "%d", pid_vnr(pid));
|
|
return cgroup_clone(task, &ns_subsys, name);
|
|
}
|
|
|
|
/*
|
|
* Rules:
|
|
* 1. you can only enter a cgroup which is a descendant of your current
|
|
* cgroup
|
|
* 2. you can only place another process into a cgroup if
|
|
* a. you have CAP_SYS_ADMIN
|
|
* b. your cgroup is an ancestor of task's destination cgroup
|
|
* (hence either you are in the same cgroup as task, or in an
|
|
* ancestor cgroup thereof)
|
|
*/
|
|
static int ns_can_attach(struct cgroup_subsys *ss, struct cgroup *new_cgroup,
|
|
struct task_struct *task, bool threadgroup)
|
|
{
|
|
if (current != task) {
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (!cgroup_is_descendant(new_cgroup, current))
|
|
return -EPERM;
|
|
}
|
|
|
|
if (!cgroup_is_descendant(new_cgroup, task))
|
|
return -EPERM;
|
|
|
|
if (threadgroup) {
|
|
struct task_struct *c;
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
|
|
if (!cgroup_is_descendant(new_cgroup, c)) {
|
|
rcu_read_unlock();
|
|
return -EPERM;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Rules: you can only create a cgroup if
|
|
* 1. you are capable(CAP_SYS_ADMIN)
|
|
* 2. the target cgroup is a descendant of your own cgroup
|
|
*/
|
|
static struct cgroup_subsys_state *ns_create(struct cgroup_subsys *ss,
|
|
struct cgroup *cgroup)
|
|
{
|
|
struct ns_cgroup *ns_cgroup;
|
|
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return ERR_PTR(-EPERM);
|
|
if (!cgroup_is_descendant(cgroup, current))
|
|
return ERR_PTR(-EPERM);
|
|
if (test_bit(CGRP_CLONE_CHILDREN, &cgroup->flags)) {
|
|
printk("ns_cgroup can't be created with parent "
|
|
"'clone_children' set.\n");
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
printk_once("ns_cgroup deprecated: consider using the "
|
|
"'clone_children' flag without the ns_cgroup.\n");
|
|
|
|
ns_cgroup = kzalloc(sizeof(*ns_cgroup), GFP_KERNEL);
|
|
if (!ns_cgroup)
|
|
return ERR_PTR(-ENOMEM);
|
|
return &ns_cgroup->css;
|
|
}
|
|
|
|
static void ns_destroy(struct cgroup_subsys *ss,
|
|
struct cgroup *cgroup)
|
|
{
|
|
struct ns_cgroup *ns_cgroup;
|
|
|
|
ns_cgroup = cgroup_to_ns(cgroup);
|
|
kfree(ns_cgroup);
|
|
}
|
|
|
|
struct cgroup_subsys ns_subsys = {
|
|
.name = "ns",
|
|
.can_attach = ns_can_attach,
|
|
.create = ns_create,
|
|
.destroy = ns_destroy,
|
|
.subsys_id = ns_subsys_id,
|
|
};
|