struct taskstats *stats; struct sk_buff *rep_skb; size_t size; u32 pid; int rc; size = taskstats_packet_size(); rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); if (rc < 0) return rc; rc = -EINVAL; pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid); if (!stats) goto err; rc = fill_stats_for_pid(pid, stats); if (rc < 0) goto err; return send_reply(rep_skb, info);err: nlmsg_free(rep_skb); return rc;} static int cmd_attr_tgid(struct genl_info *info){ struct taskstats *stats; struct sk_buff *rep_skb; size_t size; u32 tgid; int rc; size = taskstats_packet_size(); rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); if (rc < 0) return rc; rc = -EINVAL; tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid); if (!stats) goto err; rc = fill_stats_for_tgid(tgid, stats); if (rc < 0) goto err; return send_reply(rep_skb, info);err: nlmsg_free(rep_skb); return rc;} static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info){ if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK]) return cmd_attr_register_cpumask(info); else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK]) return cmd_attr_deregister_cpumask(info); else if (info->attrs[TASKSTATS_CMD_ATTR_PID]) return cmd_attr_pid(info); else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) return cmd_attr_tgid(info); else return -EINVAL;} static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk){ struct signal_struct *sig = tsk->signal; struct taskstats *stats; if (sig->stats || thread_group_empty(tsk)) goto ret; /* No problem if kmem_cache_zalloc() fails */ stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL); spin_lock_irq(&tsk->sighand->siglock); if (!sig->stats) { sig->stats = stats; stats = NULL; } spin_unlock_irq(&tsk->sighand->siglock); if (stats) kmem_cache_free(taskstats_cache, stats);ret: return sig->stats;} /* Send pid data out on exit */void taskstats_exit(struct task_struct *tsk, int group_dead){ int rc; struct listener_list *listeners; struct taskstats *stats; struct sk_buff *rep_skb; size_t size; int is_thread_group; if (!family_registered) return; /* * Size includes space for nested attributes */ size = taskstats_packet_size(); is_thread_group = !!taskstats_tgid_alloc(tsk); if (is_thread_group) { /* PID + STATS + TGID + STATS */ size = 2 * size; /* fill the tsk->signal->stats structure */ fill_tgid_exit(tsk); } listeners = __this_cpu_ptr(&listener_array); if (list_empty(&listeners->list)) return; rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size); if (rc < 0) return; stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid); if (!stats) goto err; fill_stats(tsk, stats); /* * Doesn't matter if tsk is the leader or the last group member leaving */ if (!is_thread_group || !group_dead) goto send; stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid); if (!stats) goto err; memcpy(stats, tsk->signal->stats, sizeof(*stats)); send: send_cpu_listeners(rep_skb, listeners); return;err: nlmsg_free(rep_skb);} static struct genl_ops taskstats_ops = { .cmd = TASKSTATS_CMD_GET, .doit = taskstats_user_cmd, .policy = taskstats_cmd_get_policy, .flags = GENL_ADMIN_PERM,}; static struct genl_ops cgroupstats_ops = { .cmd = CGROUPSTATS_CMD_GET, .doit = cgroupstats_user_cmd, .policy = cgroupstats_cmd_get_policy,}; /* Needed early in initialization */void __init taskstats_init_early(void){ unsigned int i; taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC); for_each_possible_cpu(i) { INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); init_rwsem(&(per_cpu(listener_array, i).sem)); }} static int __init taskstats_init(void){ int rc; rc = genl_register_family(&family); if (rc) return rc; rc = genl_register_ops(&family, &taskstats_ops); if (rc < 0) goto err; rc = genl_register_ops(&family, &cgroupstats_ops); if (rc < 0) goto err_cgroup_ops; family_registered = 1; pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION); return 0;err_cgroup_ops: genl_unregister_ops(&family, &taskstats_ops);err: genl_unregister_family(&family); return rc;} /* * late initcall ensures initialization of statistics collection * mechanisms precedes initialization of the taskstats interface */late_initcall(taskstats_init);Lines 501–709 of 709. Previous lines
struct taskstats *stats; struct sk_buff *rep_skb; size_t size; u32 pid; int rc; size = taskstats_packet_size(); rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); if (rc < 0) return rc; rc = -EINVAL; pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid); if (!stats) goto err; rc = fill_stats_for_pid(pid, stats); if (rc < 0) goto err; return send_reply(rep_skb, info); err: nlmsg_free(rep_skb); return rc; } static int cmd_attr_tgid(struct genl_info *info) { struct taskstats *stats; struct sk_buff *rep_skb; size_t size; u32 tgid; int rc; size = taskstats_packet_size(); rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); if (rc < 0) return rc; rc = -EINVAL; tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid); if (!stats) goto err; rc = fill_stats_for_tgid(tgid, stats); if (rc < 0) goto err; return send_reply(rep_skb, info); err: nlmsg_free(rep_skb); return rc; } static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) { if (info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK]) return cmd_attr_register_cpumask(info); else if (info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK]) return cmd_attr_deregister_cpumask(info); else if (info->attrs[TASKSTATS_CMD_ATTR_PID]) return cmd_attr_pid(info); else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) return cmd_attr_tgid(info); else return -EINVAL; } static struct taskstats *taskstats_tgid_alloc(struct task_struct *tsk) { struct signal_struct *sig = tsk->signal; struct taskstats *stats; if (sig->stats || thread_group_empty(tsk)) goto ret; /* No problem if kmem_cache_zalloc() fails */ stats = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL); spin_lock_irq(&tsk->sighand->siglock); if (!sig->stats) { sig->stats = stats; stats = NULL; } spin_unlock_irq(&tsk->sighand->siglock); if (stats) kmem_cache_free(taskstats_cache, stats); ret: return sig->stats; } /* Send pid data out on exit */ void taskstats_exit(struct task_struct *tsk, int group_dead) { int rc; struct listener_list *listeners; struct taskstats *stats; struct sk_buff *rep_skb; size_t size; int is_thread_group; if (!family_registered) return; /* * Size includes space for nested attributes */ size = taskstats_packet_size(); is_thread_group = !!taskstats_tgid_alloc(tsk); if (is_thread_group) { /* PID + STATS + TGID + STATS */ size = 2 * size; /* fill the tsk->signal->stats structure */ fill_tgid_exit(tsk); } listeners = __this_cpu_ptr(&listener_array); if (list_empty(&listeners->list)) return; rc = prepare_reply(NULL, TASKSTATS_CMD_NEW, &rep_skb, size); if (rc < 0) return; stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, tsk->pid); if (!stats) goto err; fill_stats(tsk, stats); /* * Doesn't matter if tsk is the leader or the last group member leaving */ if (!is_thread_group || !group_dead) goto send; stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tsk->tgid); if (!stats) goto err; memcpy(stats, tsk->signal->stats, sizeof(*stats)); send: send_cpu_listeners(rep_skb, listeners); return; err: nlmsg_free(rep_skb); } static struct genl_ops taskstats_ops = { .cmd = TASKSTATS_CMD_GET, .doit = taskstats_user_cmd, .policy = taskstats_cmd_get_policy, .flags = GENL_ADMIN_PERM, }; static struct genl_ops cgroupstats_ops = { .cmd = CGROUPSTATS_CMD_GET, .doit = cgroupstats_user_cmd, .policy = cgroupstats_cmd_get_policy, }; /* Needed early in initialization */ void __init taskstats_init_early(void) { unsigned int i; taskstats_cache = KMEM_CACHE(taskstats, SLAB_PANIC); for_each_possible_cpu(i) { INIT_LIST_HEAD(&(per_cpu(listener_array, i).list)); init_rwsem(&(per_cpu(listener_array, i).sem)); } } static int __init taskstats_init(void) { int rc; rc = genl_register_family(&family); if (rc) return rc; rc = genl_register_ops(&family, &taskstats_ops); if (rc < 0) goto err; rc = genl_register_ops(&family, &cgroupstats_ops); if (rc < 0) goto err_cgroup_ops; family_registered = 1; pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION); return 0; err_cgroup_ops: genl_unregister_ops(&family, &taskstats_ops); err: genl_unregister_family(&family); return rc; } /* * late initcall ensures initialization of statistics collection * mechanisms precedes initialization of the taskstats interface */ late_initcall(taskstats_init);