diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 173 | ||||
| -rw-r--r-- | kernel/cpuset.c | 8 | ||||
| -rw-r--r-- | kernel/fork.c | 2 | ||||
| -rw-r--r-- | kernel/nsproxy.c | 19 |
4 files changed, 192 insertions, 10 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7ad6191..b001c5d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -59,6 +59,9 @@ #include <linux/delay.h> #include <linux/atomic.h> #include <linux/cpuset.h> +#include <linux/proc_ns.h> +#include <linux/nsproxy.h> +#include <linux/proc_ns.h> #include <net/sock.h> /* @@ -212,6 +215,15 @@ static unsigned long have_fork_callback __read_mostly; static unsigned long have_exit_callback __read_mostly; static unsigned long have_free_callback __read_mostly; +/* cgroup namespace for init task */ +struct cgroup_namespace init_cgroup_ns = { + .count = { .counter = 2, }, + .user_ns = &init_user_ns, + .ns.ops = &cgroupns_operations, + .ns.inum = PROC_CGROUP_INIT_INO, + .root_cset = &init_css_set, +}; + /* Ditto for the can_fork callback. */ static unsigned long have_canfork_callback __read_mostly; @@ -2177,6 +2189,35 @@ static struct file_system_type cgroup2_fs_type = { .kill_sb = cgroup_kill_sb, }; +static char *cgroup_path_ns_locked(struct cgroup *cgrp, char *buf, size_t buflen, + struct cgroup_namespace *ns) +{ + struct cgroup *root = cset_cgroup_from_root(ns->root_cset, cgrp->root); + int ret; + + ret = kernfs_path_from_node(cgrp->kn, root->kn, buf, buflen); + if (ret < 0 || ret >= buflen) + return NULL; + return buf; +} + +char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, + struct cgroup_namespace *ns) +{ + char *ret; + + mutex_lock(&cgroup_mutex); + spin_lock_bh(&css_set_lock); + + ret = cgroup_path_ns_locked(cgrp, buf, buflen, ns); + + spin_unlock_bh(&css_set_lock); + mutex_unlock(&cgroup_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(cgroup_path_ns); + /** * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy * @task: target task @@ -2204,7 +2245,7 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen) if (root) { cgrp = task_cgroup_from_root(task, root); - path = cgroup_path(cgrp, buf, buflen); + path = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns); } else { /* if no hierarchy exists, everyone is in "/" */ if (strlcpy(buf, "/", buflen) < buflen) @@ -5297,6 +5338,8 @@ int __init cgroup_init(void) BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files)); BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files)); + get_user_ns(init_cgroup_ns.user_ns); + mutex_lock(&cgroup_mutex); /* Add init_css_set to the hash table */ @@ -5438,7 +5481,8 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, * " (deleted)" is appended to the cgroup path. */ if (cgroup_on_dfl(cgrp) || !(tsk->flags & PF_EXITING)) { - path = cgroup_path(cgrp, buf, PATH_MAX); + path = cgroup_path_ns_locked(cgrp, buf, PATH_MAX, + current->nsproxy->cgroup_ns); if (!path) { retval = -ENAMETOOLONG; goto out_unlock; @@ -5720,7 +5764,9 @@ static void cgroup_release_agent(struct work_struct *work) if (!pathbuf || !agentbuf) goto out; - path = cgroup_path(cgrp, pathbuf, PATH_MAX); + spin_lock_bh(&css_set_lock); + path = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns); + spin_unlock_bh(&css_set_lock); if (!path) goto out; @@ -5931,6 +5977,127 @@ void cgroup_sk_free(struct sock_cgroup_data *skcd) #endif /* CONFIG_SOCK_CGROUP_DATA */ +/* cgroup namespaces */ + +static struct cgroup_namespace *alloc_cgroup_ns(void) +{ + struct cgroup_namespace *new_ns; + int ret; + + new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL); + if (!new_ns) + return ERR_PTR(-ENOMEM); + ret = ns_alloc_inum(&new_ns->ns); + if (ret) { + kfree(new_ns); + return ERR_PTR(ret); + } + atomic_set(&new_ns->count, 1); + new_ns->ns.ops = &cgroupns_operations; + return new_ns; +} + +void free_cgroup_ns(struct cgroup_namespace *ns) +{ + put_css_set(ns->root_cset); + put_user_ns(ns->user_ns); + ns_free_inum(&ns->ns); + kfree(ns); +} +EXPORT_SYMBOL(free_cgroup_ns); + +struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, + struct user_namespace *user_ns, + struct cgroup_namespace *old_ns) +{ + struct cgroup_namespace *new_ns = NULL; + struct css_set *cset = NULL; + int err; + + BUG_ON(!old_ns); + + if (!(flags & CLONE_NEWCGROUP)) { + get_cgroup_ns(old_ns); + return old_ns; + } + + /* Allow only sysadmin to create cgroup namespace. */ + err = -EPERM; + if (!ns_capable(user_ns, CAP_SYS_ADMIN)) + goto err_out; + + mutex_lock(&cgroup_mutex); + spin_lock_bh(&css_set_lock); + + cset = task_css_set(current); + get_css_set(cset); + + spin_unlock_bh(&css_set_lock); + mutex_unlock(&cgroup_mutex); + + err = -ENOMEM; + new_ns = alloc_cgroup_ns(); + if (!new_ns) + goto err_out; + + new_ns->user_ns = get_user_ns(user_ns); + new_ns->root_cset = cset; + + return new_ns; + +err_out: + if (cset) + put_css_set(cset); + kfree(new_ns); + return ERR_PTR(err); +} + +static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) +{ + return container_of(ns, struct cgroup_namespace, ns); +} + +static int cgroupns_install(struct nsproxy *nsproxy, void *ns) +{ + pr_info("setns not supported for cgroup namespace"); + return -EINVAL; +} + +static struct ns_common *cgroupns_get(struct task_struct *task) +{ + struct cgroup_namespace *ns = NULL; + struct nsproxy *nsproxy; + + task_lock(task); + nsproxy = task->nsproxy; + if (nsproxy) { + ns = nsproxy->cgroup_ns; + get_cgroup_ns(ns); + } + task_unlock(task); + + return ns ? &ns->ns : NULL; +} + +static void cgroupns_put(struct ns_common *ns) +{ + put_cgroup_ns(to_cg_ns(ns)); +} + +const struct proc_ns_operations cgroupns_operations = { + .name = "cgroup", + .type = CLONE_NEWCGROUP, + .get = cgroupns_get, + .put = cgroupns_put, + .install = cgroupns_install, +}; + +static __init int cgroup_namespaces_init(void) +{ + return 0; +} +subsys_initcall(cgroup_namespaces_init); + #ifdef CONFIG_CGROUP_DEBUG static struct cgroup_subsys_state * debug_css_alloc(struct cgroup_subsys_state *parent_css) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 41989ab..d393125 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2714,10 +2714,10 @@ int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns, goto out; retval = -ENAMETOOLONG; - rcu_read_lock(); - css = task_css(tsk, cpuset_cgrp_id); - p = cgroup_path(css->cgroup, buf, PATH_MAX); - rcu_read_unlock(); + css = task_get_css(tsk, cpuset_cgrp_id); + p = cgroup_path_ns(css->cgroup, buf, PATH_MAX, + current->nsproxy->cgroup_ns); + css_put(css); if (!p) goto out_free; seq_puts(m, p); diff --git a/kernel/fork.c b/kernel/fork.c index 2e391c7..6611a62 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1884,7 +1884,7 @@ static int check_unshare_flags(unsigned long unshare_flags) if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND| CLONE_VM|CLONE_FILES|CLONE_SYSVSEM| CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET| - CLONE_NEWUSER|CLONE_NEWPID)) + CLONE_NEWUSER|CLONE_NEWPID|CLONE_NEWCGROUP)) return -EINVAL; /* * Not implemented, but pretend it works if there is nothing diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 49746c8..782102e 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -25,6 +25,7 @@ #include <linux/proc_ns.h> #include <linux/file.h> #include <linux/syscalls.h> +#include <linux/cgroup.h> static struct kmem_cache *nsproxy_cachep; @@ -39,6 +40,9 @@ struct nsproxy init_nsproxy = { #ifdef CONFIG_NET .net_ns = &init_net, #endif +#ifdef CONFIG_CGROUPS + .cgroup_ns = &init_cgroup_ns, +#endif }; static inline struct nsproxy *create_nsproxy(void) @@ -92,6 +96,13 @@ static struct nsproxy *create_new_namespaces(unsigned long flags, goto out_pid; } + new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns, + tsk->nsproxy->cgroup_ns); + if (IS_ERR(new_nsp->cgroup_ns)) { + err = PTR_ERR(new_nsp->cgroup_ns); + goto out_cgroup; + } + new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns); if (IS_ERR(new_nsp->net_ns)) { err = PTR_ERR(new_nsp->net_ns); @@ -101,6 +112,8 @@ static struct nsproxy *create_new_namespaces(unsigned long flags, return new_nsp; out_net: + put_cgroup_ns(new_nsp->cgroup_ns); +out_cgroup: if (new_nsp->pid_ns_for_children) put_pid_ns(new_nsp->pid_ns_for_children); out_pid: @@ -128,7 +141,8 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk) struct nsproxy *new_ns; if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | - CLONE_NEWPID | CLONE_NEWNET)))) { + CLONE_NEWPID | CLONE_NEWNET | + CLONE_NEWCGROUP)))) { get_nsproxy(old_ns); return 0; } @@ -165,6 +179,7 @@ void free_nsproxy(struct nsproxy *ns) put_ipc_ns(ns->ipc_ns); if (ns->pid_ns_for_children) put_pid_ns(ns->pid_ns_for_children); + put_cgroup_ns(ns->cgroup_ns); put_net(ns->net_ns); kmem_cache_free(nsproxy_cachep, ns); } @@ -180,7 +195,7 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags, int err = 0; if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | - CLONE_NEWNET | CLONE_NEWPID))) + CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP))) return 0; user_ns = new_cred ? new_cred->user_ns : current_user_ns(); |
