diff options
| -rw-r--r-- | fs/proc/base.c | 2 | ||||
| -rw-r--r-- | include/linux/pid.h | 16 | ||||
| -rw-r--r-- | include/linux/sched.h | 31 | ||||
| -rw-r--r-- | kernel/pid.c | 43 |
4 files changed, 70 insertions, 22 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 36983e7..50e149e 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2333,7 +2333,7 @@ static struct task_struct *next_tgid(unsigned int tgid) rcu_read_lock(); retry: task = NULL; - pid = find_ge_pid(tgid); + pid = find_ge_pid(tgid, &init_pid_ns); if (pid) { tgid = pid->nr + 1; task = pid_task(pid, PIDTYPE_PID); diff --git a/include/linux/pid.h b/include/linux/pid.h index c5fee61..0dc940f 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -99,17 +99,29 @@ extern void FASTCALL(detach_pid(struct task_struct *task, enum pid_type)); extern void FASTCALL(transfer_pid(struct task_struct *old, struct task_struct *new, enum pid_type)); +struct pid_namespace; +extern struct pid_namespace init_pid_ns; + /* * look up a PID in the hash table. Must be called with the tasklist_lock * or rcu_read_lock() held. + * + * find_pid_ns() finds the pid in the namespace specified + * find_pid() find the pid by its global id, i.e. in the init namespace + * find_vpid() finr the pid by its virtual id, i.e. in the current namespace + * + * see also find_task_by_pid() set in include/linux/sched.h */ -extern struct pid *FASTCALL(find_pid(int nr)); +extern struct pid *FASTCALL(find_pid_ns(int nr, struct pid_namespace *ns)); + +#define find_vpid(pid) find_pid_ns(pid, current->nsproxy->pid_ns) +#define find_pid(pid) find_pid_ns(pid, &init_pid_ns) /* * Lookup a PID in the hash table, and return with it's count elevated. */ extern struct pid *find_get_pid(int nr); -extern struct pid *find_ge_pid(int nr); +extern struct pid *find_ge_pid(int nr, struct pid_namespace *); extern struct pid *alloc_pid(struct pid_namespace *ns); extern void FASTCALL(free_pid(struct pid *pid)); diff --git a/include/linux/sched.h b/include/linux/sched.h index 77e8cad..511cc45 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1514,8 +1514,35 @@ extern struct task_struct init_task; extern struct mm_struct init_mm; -#define find_task_by_pid(nr) find_task_by_pid_type(PIDTYPE_PID, nr) -extern struct task_struct *find_task_by_pid_type(int type, int pid); +extern struct pid_namespace init_pid_ns; + +/* + * find a task by one of its numerical ids + * + * find_task_by_pid_type_ns(): + * it is the most generic call - it finds a task by all id, + * type and namespace specified + * find_task_by_pid_ns(): + * finds a task by its pid in the specified namespace + * find_task_by_pid_type(): + * finds a task by its global id with the specified type, e.g. + * by global session id + * find_task_by_pid(): + * finds a task by its global pid + * + * see also find_pid() etc in include/linux/pid.h + */ + +extern struct task_struct *find_task_by_pid_type_ns(int type, int pid, + struct pid_namespace *ns); + +#define find_task_by_pid_ns(nr, ns) \ + find_task_by_pid_type_ns(PIDTYPE_PID, nr, ns) +#define find_task_by_pid_type(type, nr) \ + find_task_by_pid_type_ns(type, nr, &init_pid_ns) +#define find_task_by_pid(nr) \ + find_task_by_pid_type(PIDTYPE_PID, nr) + extern void __set_special_pids(pid_t session, pid_t pgrp); /* per-UID process charging. */ diff --git a/kernel/pid.c b/kernel/pid.c index 6eb1484..a2b4cbb 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -71,6 +71,7 @@ struct pid_namespace init_pid_ns = { .level = 0, .child_reaper = &init_task, }; +EXPORT_SYMBOL_GPL(init_pid_ns); int is_global_init(struct task_struct *tsk) { @@ -210,7 +211,8 @@ fastcall void free_pid(struct pid *pid) unsigned long flags; spin_lock_irqsave(&pidmap_lock, flags); - hlist_del_rcu(&pid->pid_chain); + for (i = 0; i <= pid->level; i++) + hlist_del_rcu(&pid->numbers[i].pid_chain); spin_unlock_irqrestore(&pidmap_lock, flags); for (i = 0; i <= pid->level; i++) @@ -225,6 +227,7 @@ struct pid *alloc_pid(struct pid_namespace *ns) enum pid_type type; int i, nr; struct pid_namespace *tmp; + struct upid *upid; pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL); if (!pid) @@ -251,7 +254,11 @@ struct pid *alloc_pid(struct pid_namespace *ns) INIT_HLIST_HEAD(&pid->tasks[type]); spin_lock_irq(&pidmap_lock); - hlist_add_head_rcu(&pid->pid_chain, &pid_hash[pid_hashfn(pid->nr, ns)]); + for (i = ns->level; i >= 0; i--) { + upid = &pid->numbers[i]; + hlist_add_head_rcu(&upid->pid_chain, + &pid_hash[pid_hashfn(upid->nr, upid->ns)]); + } spin_unlock_irq(&pidmap_lock); out: @@ -266,19 +273,20 @@ out_free: goto out; } -struct pid * fastcall find_pid(int nr) +struct pid * fastcall find_pid_ns(int nr, struct pid_namespace *ns) { struct hlist_node *elem; - struct pid *pid; + struct upid *pnr; + + hlist_for_each_entry_rcu(pnr, elem, + &pid_hash[pid_hashfn(nr, ns)], pid_chain) + if (pnr->nr == nr && pnr->ns == ns) + return container_of(pnr, struct pid, + numbers[ns->level]); - hlist_for_each_entry_rcu(pid, elem, - &pid_hash[pid_hashfn(nr, &init_pid_ns)], pid_chain) { - if (pid->nr == nr) - return pid; - } return NULL; } -EXPORT_SYMBOL_GPL(find_pid); +EXPORT_SYMBOL_GPL(find_pid_ns); /* * attach_pid() must be called with the tasklist_lock write-held. @@ -338,12 +346,13 @@ struct task_struct * fastcall pid_task(struct pid *pid, enum pid_type type) /* * Must be called under rcu_read_lock() or with tasklist_lock read-held. */ -struct task_struct *find_task_by_pid_type(int type, int nr) +struct task_struct *find_task_by_pid_type_ns(int type, int nr, + struct pid_namespace *ns) { - return pid_task(find_pid(nr), type); + return pid_task(find_pid_ns(nr, ns), type); } -EXPORT_SYMBOL(find_task_by_pid_type); +EXPORT_SYMBOL(find_task_by_pid_type_ns); struct pid *get_task_pid(struct task_struct *task, enum pid_type type) { @@ -370,7 +379,7 @@ struct pid *find_get_pid(pid_t nr) struct pid *pid; rcu_read_lock(); - pid = get_pid(find_pid(nr)); + pid = get_pid(find_vpid(nr)); rcu_read_unlock(); return pid; @@ -394,15 +403,15 @@ pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns) * * 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 *find_ge_pid(int nr, struct pid_namespace *ns) { struct pid *pid; do { - pid = find_pid(nr); + pid = find_pid_ns(nr, ns); if (pid) break; - nr = next_pidmap(task_active_pid_ns(current), nr); + nr = next_pidmap(ns, nr); } while (nr > 0); return pid; |
