#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
+#include <linux/rculist.h>
#include <linux/bootmem.h>
#include <linux/hash.h>
#include <linux/pid_namespace.h>
static struct hlist_head *pid_hash;
static int pidhash_shift;
struct pid init_struct_pid = INIT_STRUCT_PID;
-static struct kmem_cache *pid_ns_cachep;
int pid_max = PID_MAX_DEFAULT;
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(pidmap_lock);
-static fastcall void free_pidmap(struct pid_namespace *pid_ns, int pid)
+static void free_pidmap(struct upid *upid)
{
- struct pidmap *map = pid_ns->pidmap + pid / BITS_PER_PAGE;
- int offset = pid & BITS_PER_PAGE_MASK;
+ int nr = upid->nr;
+ struct pidmap *map = upid->ns->pidmap + nr / BITS_PER_PAGE;
+ int offset = nr & BITS_PER_PAGE_MASK;
clear_bit(offset, map->page);
atomic_inc(&map->nr_free);
return -1;
}
-static int next_pidmap(struct pid_namespace *pid_ns, int last)
+int next_pidmap(struct pid_namespace *pid_ns, int last)
{
int offset;
struct pidmap *map, *end;
return -1;
}
-fastcall void put_pid(struct pid *pid)
+void put_pid(struct pid *pid)
{
struct pid_namespace *ns;
put_pid(pid);
}
-fastcall void free_pid(struct pid *pid)
+void free_pid(struct pid *pid)
{
/* We can be called with write_lock_irq(&tasklist_lock) held */
int i;
spin_unlock_irqrestore(&pidmap_lock, flags);
for (i = 0; i <= pid->level; i++)
- free_pidmap(pid->numbers[i].ns, pid->numbers[i].nr);
+ free_pidmap(pid->numbers + i);
call_rcu(&pid->rcu, delayed_put_pid);
}
get_pid_ns(ns);
pid->level = ns->level;
- pid->nr = pid->numbers[0].nr;
atomic_set(&pid->count, 1);
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);
return pid;
out_free:
- for (i++; i <= ns->level; i++)
- free_pidmap(pid->numbers[i].ns, pid->numbers[i].nr);
+ while (++i <= ns->level)
+ free_pidmap(pid->numbers + i);
kmem_cache_free(ns->pid_cachep, pid);
pid = NULL;
goto out;
}
-struct pid * fastcall find_pid_ns(int nr, struct pid_namespace *ns)
+struct pid *find_pid_ns(int nr, struct pid_namespace *ns)
{
struct hlist_node *elem;
struct upid *pnr;
}
EXPORT_SYMBOL_GPL(find_pid_ns);
+struct pid *find_vpid(int nr)
+{
+ return find_pid_ns(nr, current->nsproxy->pid_ns);
+}
+EXPORT_SYMBOL_GPL(find_vpid);
+
/*
* attach_pid() must be called with the tasklist_lock write-held.
*/
-int fastcall attach_pid(struct task_struct *task, enum pid_type type,
+void attach_pid(struct task_struct *task, enum pid_type type,
struct pid *pid)
{
struct pid_link *link;
link = &task->pids[type];
link->pid = pid;
hlist_add_head_rcu(&link->node, &pid->tasks[type]);
-
- return 0;
}
-void fastcall detach_pid(struct task_struct *task, enum pid_type type)
+static void __change_pid(struct task_struct *task, enum pid_type type,
+ struct pid *new)
{
struct pid_link *link;
struct pid *pid;
pid = link->pid;
hlist_del_rcu(&link->node);
- link->pid = NULL;
+ link->pid = new;
for (tmp = PIDTYPE_MAX; --tmp >= 0; )
if (!hlist_empty(&pid->tasks[tmp]))
free_pid(pid);
}
+void detach_pid(struct task_struct *task, enum pid_type type)
+{
+ __change_pid(task, type, NULL);
+}
+
+void change_pid(struct task_struct *task, enum pid_type type,
+ struct pid *pid)
+{
+ __change_pid(task, type, pid);
+ attach_pid(task, type, pid);
+}
+
/* transfer_pid is an optimization of attach_pid(new), detach_pid(old) */
-void fastcall transfer_pid(struct task_struct *old, struct task_struct *new,
+void transfer_pid(struct task_struct *old, struct task_struct *new,
enum pid_type type)
{
new->pids[type].pid = old->pids[type].pid;
hlist_replace_rcu(&old->pids[type].node, &new->pids[type].node);
- old->pids[type].pid = NULL;
}
-struct task_struct * fastcall pid_task(struct pid *pid, enum pid_type type)
+struct task_struct *pid_task(struct pid *pid, enum pid_type type)
{
struct task_struct *result = NULL;
if (pid) {
}
return result;
}
+EXPORT_SYMBOL(pid_task);
/*
* Must be called under rcu_read_lock() or with tasklist_lock read-held.
*/
-struct task_struct *find_task_by_pid_type_ns(int type, int nr,
- struct pid_namespace *ns)
-{
- return pid_task(find_pid_ns(nr, ns), type);
-}
-
-EXPORT_SYMBOL(find_task_by_pid_type_ns);
-
-struct task_struct *find_task_by_pid(pid_t nr)
+struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
{
- return find_task_by_pid_type_ns(PIDTYPE_PID, nr, &init_pid_ns);
+ return pid_task(find_pid_ns(nr, ns), PIDTYPE_PID);
}
-EXPORT_SYMBOL(find_task_by_pid);
struct task_struct *find_task_by_vpid(pid_t vnr)
{
- return find_task_by_pid_type_ns(PIDTYPE_PID, vnr,
- current->nsproxy->pid_ns);
+ return find_task_by_pid_ns(vnr, current->nsproxy->pid_ns);
}
-EXPORT_SYMBOL(find_task_by_vpid);
-
-struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
-{
- return find_task_by_pid_type_ns(PIDTYPE_PID, nr, ns);
-}
-EXPORT_SYMBOL(find_task_by_pid_ns);
struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
{
struct pid *pid;
rcu_read_lock();
+ if (type != PIDTYPE_PID)
+ task = task->group_leader;
pid = get_pid(task->pids[type].pid);
rcu_read_unlock();
return pid;
}
-struct task_struct *fastcall get_pid_task(struct pid *pid, enum pid_type type)
+struct task_struct *get_pid_task(struct pid *pid, enum pid_type type)
{
struct task_struct *result;
rcu_read_lock();
return pid;
}
+EXPORT_SYMBOL_GPL(find_get_pid);
pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns)
{
return nr;
}
-/*
- * Used by proc to find the first pid that is greater then or equal to nr.
- *
- * If there is a pid at nr this function is exactly the same as find_pid.
- */
-struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
+pid_t pid_vnr(struct pid *pid)
{
- struct pid *pid;
-
- do {
- pid = find_pid_ns(nr, ns);
- if (pid)
- break;
- nr = next_pidmap(ns, nr);
- } while (nr > 0);
-
- return pid;
+ return pid_nr_ns(pid, current->nsproxy->pid_ns);
}
-EXPORT_SYMBOL_GPL(find_get_pid);
-
-struct pid_cache {
- int nr_ids;
- char name[16];
- struct kmem_cache *cachep;
- struct list_head list;
-};
+EXPORT_SYMBOL_GPL(pid_vnr);
-static LIST_HEAD(pid_caches_lh);
-static DEFINE_MUTEX(pid_caches_mutex);
-
-/*
- * creates the kmem cache to allocate pids from.
- * @nr_ids: the number of numerical ids this pid will have to carry
- */
-
-static struct kmem_cache *create_pid_cachep(int nr_ids)
+pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
+ struct pid_namespace *ns)
{
- struct pid_cache *pcache;
- struct kmem_cache *cachep;
-
- mutex_lock(&pid_caches_mutex);
- list_for_each_entry (pcache, &pid_caches_lh, list)
- if (pcache->nr_ids == nr_ids)
- goto out;
-
- pcache = kmalloc(sizeof(struct pid_cache), GFP_KERNEL);
- if (pcache == NULL)
- goto err_alloc;
-
- snprintf(pcache->name, sizeof(pcache->name), "pid_%d", nr_ids);
- cachep = kmem_cache_create(pcache->name,
- sizeof(struct pid) + (nr_ids - 1) * sizeof(struct upid),
- 0, SLAB_HWCACHE_ALIGN, NULL);
- if (cachep == NULL)
- goto err_cachep;
-
- pcache->nr_ids = nr_ids;
- pcache->cachep = cachep;
- list_add(&pcache->list, &pid_caches_lh);
-out:
- mutex_unlock(&pid_caches_mutex);
- return pcache->cachep;
-
-err_cachep:
- kfree(pcache);
-err_alloc:
- mutex_unlock(&pid_caches_mutex);
- return NULL;
-}
-
-static struct pid_namespace *create_pid_namespace(int level)
-{
- struct pid_namespace *ns;
- int i;
-
- ns = kmem_cache_alloc(pid_ns_cachep, GFP_KERNEL);
- if (ns == NULL)
- goto out;
-
- ns->pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL);
- if (!ns->pidmap[0].page)
- goto out_free;
-
- ns->pid_cachep = create_pid_cachep(level + 1);
- if (ns->pid_cachep == NULL)
- goto out_free_map;
-
- kref_init(&ns->kref);
- ns->last_pid = 0;
- ns->child_reaper = NULL;
- ns->level = level;
-
- set_bit(0, ns->pidmap[0].page);
- atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1);
+ pid_t nr = 0;
- for (i = 1; i < PIDMAP_ENTRIES; i++) {
- ns->pidmap[i].page = 0;
- atomic_set(&ns->pidmap[i].nr_free, BITS_PER_PAGE);
+ rcu_read_lock();
+ if (!ns)
+ ns = current->nsproxy->pid_ns;
+ if (likely(pid_alive(task))) {
+ if (type != PIDTYPE_PID)
+ task = task->group_leader;
+ nr = pid_nr_ns(task->pids[type].pid, ns);
}
+ rcu_read_unlock();
- return ns;
-
-out_free_map:
- kfree(ns->pidmap[0].page);
-out_free:
- kmem_cache_free(pid_ns_cachep, ns);
-out:
- return ERR_PTR(-ENOMEM);
+ return nr;
}
+EXPORT_SYMBOL(__task_pid_nr_ns);
-static void destroy_pid_namespace(struct pid_namespace *ns)
+pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
{
- int i;
-
- for (i = 0; i < PIDMAP_ENTRIES; i++)
- kfree(ns->pidmap[i].page);
- kmem_cache_free(pid_ns_cachep, ns);
+ return pid_nr_ns(task_tgid(tsk), ns);
}
+EXPORT_SYMBOL(task_tgid_nr_ns);
-struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns)
+struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
{
- struct pid_namespace *new_ns;
-
- BUG_ON(!old_ns);
- new_ns = get_pid_ns(old_ns);
- if (!(flags & CLONE_NEWPID))
- goto out;
-
- new_ns = ERR_PTR(-EINVAL);
- if (flags & CLONE_THREAD)
- goto out_put;
-
- new_ns = create_pid_namespace(old_ns->level + 1);
- if (!IS_ERR(new_ns))
- new_ns->parent = get_pid_ns(old_ns);
-
-out_put:
- put_pid_ns(old_ns);
-out:
- return new_ns;
+ return ns_of_pid(task_pid(tsk));
}
+EXPORT_SYMBOL_GPL(task_active_pid_ns);
-void free_pid_ns(struct kref *kref)
-{
- struct pid_namespace *ns, *parent;
-
- ns = container_of(kref, struct pid_namespace, kref);
-
- parent = ns->parent;
- destroy_pid_namespace(ns);
-
- if (parent != NULL)
- put_pid_ns(parent);
-}
-
-void zap_pid_ns_processes(struct pid_namespace *pid_ns)
+/*
+ * Used by proc to find the first pid that is greater than or equal to nr.
+ *
+ * If there is a pid at nr this function is exactly the same as find_pid_ns.
+ */
+struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
{
- int nr;
- int rc;
-
- /*
- * The last thread in the cgroup-init thread group is terminating.
- * Find remaining pid_ts in the namespace, signal and wait for them
- * to exit.
- *
- * Note: This signals each threads in the namespace - even those that
- * belong to the same thread group, To avoid this, we would have
- * to walk the entire tasklist looking a processes in this
- * namespace, but that could be unnecessarily expensive if the
- * pid namespace has just a few processes. Or we need to
- * maintain a tasklist for each pid namespace.
- *
- */
- read_lock(&tasklist_lock);
- nr = next_pidmap(pid_ns, 1);
- while (nr > 0) {
- kill_proc_info(SIGKILL, SEND_SIG_PRIV, nr);
- nr = next_pidmap(pid_ns, nr);
- }
- read_unlock(&tasklist_lock);
+ struct pid *pid;
do {
- clear_thread_flag(TIF_SIGPENDING);
- rc = sys_wait4(-1, NULL, __WALL, NULL);
- } while (rc != -ECHILD);
-
+ pid = find_pid_ns(nr, ns);
+ if (pid)
+ break;
+ nr = next_pidmap(ns, nr);
+ } while (nr > 0);
- /* Child reaper for the pid namespace is going away */
- pid_ns->child_reaper = NULL;
- return;
+ return pid;
}
/*
set_bit(0, init_pid_ns.pidmap[0].page);
atomic_dec(&init_pid_ns.pidmap[0].nr_free);
- init_pid_ns.pid_cachep = create_pid_cachep(1);
- if (init_pid_ns.pid_cachep == NULL)
- panic("Can't create pid_1 cachep\n");
-
- pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC);
+ init_pid_ns.pid_cachep = KMEM_CACHE(pid,
+ SLAB_HWCACHE_ALIGN | SLAB_PANIC);
}
Code Review / linux-2.6.git / blobdiff