diff options
Diffstat (limited to 'kernel/pid_namespace.c')
| -rw-r--r-- | kernel/pid_namespace.c | 59 |
1 files changed, 26 insertions, 33 deletions
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 4918314893bc..0b53eef7d34b 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -21,6 +21,7 @@ #include <linux/export.h> #include <linux/sched/task.h> #include <linux/sched/signal.h> +#include <linux/idr.h> struct pid_cache { int nr_ids; @@ -98,7 +99,6 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns struct pid_namespace *ns; unsigned int level = parent_pid_ns->level + 1; struct ucounts *ucounts; - int i; int err; err = -EINVAL; @@ -117,17 +117,15 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns if (ns == NULL) goto out_dec; - ns->pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL); - if (!ns->pidmap[0].page) - goto out_free; + idr_init(&ns->idr); ns->pid_cachep = create_pid_cachep(level + 1); if (ns->pid_cachep == NULL) - goto out_free_map; + goto out_free_idr; err = ns_alloc_inum(&ns->ns); if (err) - goto out_free_map; + goto out_free_idr; ns->ns.ops = &pidns_operations; kref_init(&ns->kref); @@ -135,20 +133,13 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns ns->parent = get_pid_ns(parent_pid_ns); ns->user_ns = get_user_ns(user_ns); ns->ucounts = ucounts; - ns->nr_hashed = PIDNS_HASH_ADDING; + ns->pid_allocated = PIDNS_ADDING; INIT_WORK(&ns->proc_work, proc_cleanup_work); - set_bit(0, ns->pidmap[0].page); - atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1); - - for (i = 1; i < PIDMAP_ENTRIES; i++) - atomic_set(&ns->pidmap[i].nr_free, BITS_PER_PAGE); - return ns; -out_free_map: - kfree(ns->pidmap[0].page); -out_free: +out_free_idr: + idr_destroy(&ns->idr); kmem_cache_free(pid_ns_cachep, ns); out_dec: dec_pid_namespaces(ucounts); @@ -168,11 +159,9 @@ static void delayed_free_pidns(struct rcu_head *p) static void destroy_pid_namespace(struct pid_namespace *ns) { - int i; - ns_free_inum(&ns->ns); - for (i = 0; i < PIDMAP_ENTRIES; i++) - kfree(ns->pidmap[i].page); + + idr_destroy(&ns->idr); call_rcu(&ns->rcu, delayed_free_pidns); } @@ -213,6 +202,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) int rc; struct task_struct *task, *me = current; int init_pids = thread_group_leader(me) ? 1 : 2; + struct pid *pid; /* Don't allow any more processes into the pid namespace */ disable_pid_allocation(pid_ns); @@ -239,20 +229,16 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) * maintain a tasklist for each pid namespace. * */ + rcu_read_lock(); read_lock(&tasklist_lock); - nr = next_pidmap(pid_ns, 1); - while (nr > 0) { - rcu_read_lock(); - - task = pid_task(find_vpid(nr), PIDTYPE_PID); + nr = 2; + idr_for_each_entry_continue(&pid_ns->idr, pid, nr) { + task = pid_task(pid, PIDTYPE_PID); if (task && !__fatal_signal_pending(task)) send_sig_info(SIGKILL, SEND_SIG_FORCED, task); - - rcu_read_unlock(); - - nr = next_pidmap(pid_ns, nr); } read_unlock(&tasklist_lock); + rcu_read_unlock(); /* * Reap the EXIT_ZOMBIE children we had before we ignored SIGCHLD. @@ -268,7 +254,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) * sys_wait4() above can't reap the EXIT_DEAD children but we do not * really care, we could reparent them to the global init. We could * exit and reap ->child_reaper even if it is not the last thread in - * this pid_ns, free_pid(nr_hashed == 0) calls proc_cleanup_work(), + * this pid_ns, free_pid(pid_allocated == 0) calls proc_cleanup_work(), * pid_ns can not go away until proc_kill_sb() drops the reference. * * But this ns can also have other tasks injected by setns()+fork(). @@ -282,7 +268,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) */ for (;;) { set_current_state(TASK_INTERRUPTIBLE); - if (pid_ns->nr_hashed == init_pids) + if (pid_ns->pid_allocated == init_pids) break; schedule(); } @@ -301,6 +287,7 @@ static int pid_ns_ctl_handler(struct ctl_table *table, int write, { struct pid_namespace *pid_ns = task_active_pid_ns(current); struct ctl_table tmp = *table; + int ret, next; if (write && !ns_capable(pid_ns->user_ns, CAP_SYS_ADMIN)) return -EPERM; @@ -311,8 +298,14 @@ static int pid_ns_ctl_handler(struct ctl_table *table, int write, * it should synchronize its usage with external means. */ - tmp.data = &pid_ns->last_pid; - return proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + next = idr_get_cursor(&pid_ns->idr) - 1; + + tmp.data = &next; + ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); + if (!ret && write) + idr_set_cursor(&pid_ns->idr, next + 1); + + return ret; } extern int pid_max; |