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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/kernel.h>#include <linux/taskstats_kern.h>#include <linux/tsacct_kern.h>#include <linux/acct.h>#include <linux/delayacct.h>#include <linux/cpumask.h>#include <linux/percpu.h>#include <linux/slab.h>#include <linux/cgroupstats.h>#include <linux/cgroup.h>#include <linux/fs.h>#include <linux/file.h>#include <linux/pid_namespace.h>#include <net/genetlink.h>#include <linux/atomic.h>#include <linux/sched/cputime.h>
/* * Maximum length of a cpumask that can be specified in * the TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK attribute */#define TASKSTATS_CPUMASK_MAXLEN (100+6*NR_CPUS)
static DEFINE_PER_CPU(__u32, taskstats_seqnum);static int family_registered;struct kmem_cache *taskstats_cache;
static struct genl_family family;
static const struct nla_policy taskstats_cmd_get_policy[] = { [TASKSTATS_CMD_ATTR_PID] = { .type = NLA_U32 }, [TASKSTATS_CMD_ATTR_TGID] = { .type = NLA_U32 }, [TASKSTATS_CMD_ATTR_REGISTER_CPUMASK] = { .type = NLA_STRING }, [TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK] = { .type = NLA_STRING },};
static const struct nla_policy cgroupstats_cmd_get_policy[] = { [CGROUPSTATS_CMD_ATTR_FD] = { .type = NLA_U32 },};
struct listener { struct list_head list; pid_t pid; char valid;};
struct listener_list { struct rw_semaphore sem; struct list_head list;};static DEFINE_PER_CPU(struct listener_list, listener_array);
enum actions { REGISTER, DEREGISTER, CPU_DONT_CARE};
static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, size_t size){ struct sk_buff *skb; void *reply;
/* * If new attributes are added, please revisit this allocation */ skb = genlmsg_new(size, GFP_KERNEL); if (!skb) return -ENOMEM;
if (!info) { int seq = this_cpu_inc_return(taskstats_seqnum) - 1;
reply = genlmsg_put(skb, 0, seq, &family, 0, cmd); } else reply = genlmsg_put_reply(skb, info, &family, 0, cmd); if (reply == NULL) { nlmsg_free(skb); return -EINVAL; }
*skbp = skb; return 0;}
/* * Send taskstats data in @skb to listener with nl_pid @pid */static int send_reply(struct sk_buff *skb, struct genl_info *info){ struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); void *reply = genlmsg_data(genlhdr);
genlmsg_end(skb, reply);
return genlmsg_reply(skb, info);}
/* * Send taskstats data in @skb to listeners registered for @cpu's exit data */static void send_cpu_listeners(struct sk_buff *skb, struct listener_list *listeners){ struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb)); struct listener *s, *tmp; struct sk_buff *skb_next, *skb_cur = skb; void *reply = genlmsg_data(genlhdr); int delcount = 0;
genlmsg_end(skb, reply);
down_read(&listeners->sem); list_for_each_entry(s, &listeners->list, list) { int rc;
skb_next = NULL; if (!list_is_last(&s->list, &listeners->list)) { skb_next = skb_clone(skb_cur, GFP_KERNEL); if (!skb_next) break; } rc = genlmsg_unicast(&init_net, skb_cur, s->pid); if (rc == -ECONNREFUSED) { s->valid = 0; delcount++; } skb_cur = skb_next; } up_read(&listeners->sem);
if (skb_cur) nlmsg_free(skb_cur);
if (!delcount) return;
/* Delete invalidated entries */ down_write(&listeners->sem); list_for_each_entry_safe(s, tmp, &listeners->list, list) { if (!s->valid) { list_del(&s->list); kfree(s); } } up_write(&listeners->sem);}
static void exe_add_tsk(struct taskstats *stats, struct task_struct *tsk){ /* No idea if I'm allowed to access that here, now. */ struct file *exe_file = get_task_exe_file(tsk);
if (exe_file) { /* Following cp_new_stat64() in stat.c . */ stats->ac_exe_dev = huge_encode_dev(exe_file->f_inode->i_sb->s_dev); stats->ac_exe_inode = exe_file->f_inode->i_ino; fput(exe_file); } else { stats->ac_exe_dev = 0; stats->ac_exe_inode = 0; }}
static void fill_stats(struct user_namespace *user_ns, struct pid_namespace *pid_ns, struct task_struct *tsk, struct taskstats *stats){ memset(stats, 0, sizeof(*stats)); /* * Each accounting subsystem adds calls to its functions to * fill in relevant parts of struct taskstsats as follows * * per-task-foo(stats, tsk); */
delayacct_add_tsk(stats, tsk);
/* fill in basic acct fields */ stats->version = TASKSTATS_VERSION; stats->nvcsw = tsk->nvcsw; stats->nivcsw = tsk->nivcsw; bacct_add_tsk(user_ns, pid_ns, stats, tsk);
/* fill in extended acct fields */ xacct_add_tsk(stats, tsk);
/* add executable info */ exe_add_tsk(stats, tsk);}
static int fill_stats_for_pid(pid_t pid, struct taskstats *stats){ struct task_struct *tsk;
tsk = find_get_task_by_vpid(pid); if (!tsk) return -ESRCH; fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats); put_task_struct(tsk); return 0;}
static void tgid_stats_add_task(struct taskstats *stats, struct task_struct *tsk, u64 now_ns){ u64 delta, utime, stime;
/* * Each accounting subsystem calls its functions here to * accumulate its per-task stats for tsk, into the per-tgid structure * * per-task-foo(stats, tsk); */ delayacct_add_tsk(stats, tsk);
/* calculate task elapsed time in nsec */ delta = now_ns - tsk->start_time; /* Convert to micro seconds */ do_div(delta, NSEC_PER_USEC); stats->ac_etime += delta;
task_cputime(tsk, &utime, &stime); stats->ac_utime += div_u64(utime, NSEC_PER_USEC); stats->ac_stime += div_u64(stime, NSEC_PER_USEC);
stats->nvcsw += tsk->nvcsw; stats->nivcsw += tsk->nivcsw;}
static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats){ struct task_struct *tsk, *first; unsigned long flags; int rc = -ESRCH; u64 now_ns;
/* * Add additional stats from live tasks except zombie thread group * leaders who are already counted with the dead tasks */ rcu_read_lock(); first = find_task_by_vpid(tgid);
if (!first || !lock_task_sighand(first, &flags)) goto out;
if (first->signal->stats) memcpy(stats, first->signal->stats, sizeof(*stats)); else memset(stats, 0, sizeof(*stats));
now_ns = ktime_get_ns(); for_each_thread(first, tsk) { if (tsk->exit_state) continue;
tgid_stats_add_task(stats, tsk, now_ns); }
unlock_task_sighand(first, &flags); rc = 0;out: rcu_read_unlock();
stats->version = TASKSTATS_VERSION; /* * Accounting subsystems can also add calls here to modify * fields of taskstats. */ return rc;}
static void fill_tgid_exit(struct task_struct *tsk){ unsigned long flags; u64 now_ns;
spin_lock_irqsave(&tsk->sighand->siglock, flags); if (!tsk->signal->stats) goto ret;
now_ns = ktime_get_ns(); tgid_stats_add_task(tsk->signal->stats, tsk, now_ns);ret: spin_unlock_irqrestore(&tsk->sighand->siglock, flags); return;}
static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd){ struct listener_list *listeners; struct listener *s, *tmp, *s2; unsigned int cpu; int ret = 0;
if (!cpumask_subset(mask, cpu_possible_mask)) return -EINVAL;
if (current_user_ns() != &init_user_ns) return -EINVAL;
if (task_active_pid_ns(current) != &init_pid_ns) return -EINVAL;
if (isadd == REGISTER) { for_each_cpu(cpu, mask) { s = kmalloc_node(sizeof(struct listener), GFP_KERNEL, cpu_to_node(cpu)); if (!s) { ret = -ENOMEM; goto cleanup; } s->pid = pid; s->valid = 1;
listeners = &per_cpu(listener_array, cpu); down_write(&listeners->sem); list_for_each_entry(s2, &listeners->list, list) { if (s2->pid == pid && s2->valid) goto exists; } list_add(&s->list, &listeners->list); s = NULL;exists: up_write(&listeners->sem); kfree(s); /* nop if NULL */ } return 0; }
/* Deregister or cleanup */cleanup: for_each_cpu(cpu, mask) { listeners = &per_cpu(listener_array, cpu); down_write(&listeners->sem); list_for_each_entry_safe(s, tmp, &listeners->list, list) { if (s->pid == pid) { list_del(&s->list); kfree(s); break; } } up_write(&listeners->sem); } return ret;}
static int parse(struct nlattr *na, struct cpumask *mask){ char *data; int len; int ret;
if (na == NULL) return 1; len = nla_len(na); if (len > TASKSTATS_CPUMASK_MAXLEN) return -E2BIG; if (len < 1) return -EINVAL; data = kmalloc(len, GFP_KERNEL); if (!data) return -ENOMEM; nla_strscpy(data, na, len); ret = cpulist_parse(data, mask); kfree(data); return ret;}
static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid){ struct nlattr *na, *ret; int aggr;
aggr = (type == TASKSTATS_TYPE_PID) ? TASKSTATS_TYPE_AGGR_PID : TASKSTATS_TYPE_AGGR_TGID;
na = nla_nest_start_noflag(skb, aggr); if (!na) goto err;
if (nla_put(skb, type, sizeof(pid), &pid) < 0) { nla_nest_cancel(skb, na); goto err; } ret = nla_reserve_64bit(skb, TASKSTATS_TYPE_STATS, sizeof(struct taskstats), TASKSTATS_TYPE_NULL); if (!ret) { nla_nest_cancel(skb, na); goto err; } nla_nest_end(skb, na);
return nla_data(ret);err: return NULL;}
static int cgroupstats_user_cmd(struct sk_buff *skb, struct genl_info *info){ int rc = 0; struct sk_buff *rep_skb; struct cgroupstats *stats; struct nlattr *na; size_t size; u32 fd;
na = info->attrs[CGROUPSTATS_CMD_ATTR_FD]; if (!na) return -EINVAL;
fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]); CLASS(fd, f)(fd); if (fd_empty(f)) return 0;
size = nla_total_size(sizeof(struct cgroupstats));
rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb, size); if (rc < 0) return rc;
na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS, sizeof(struct cgroupstats)); if (na == NULL) { nlmsg_free(rep_skb); return -EMSGSIZE; }
stats = nla_data(na); memset(stats, 0, sizeof(*stats));
rc = cgroupstats_build(stats, fd_file(f)->f_path.dentry); if (rc < 0) { nlmsg_free(rep_skb); return rc; }
return send_reply(rep_skb, info);}
static int cmd_attr_register_cpumask(struct genl_info *info){ cpumask_var_t mask; int rc;
if (!alloc_cpumask_var(&mask, GFP_KERNEL)) return -ENOMEM; rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], mask); if (rc < 0) goto out; rc = add_del_listener(info->snd_portid, mask, REGISTER);out: free_cpumask_var(mask); return rc;}
static int cmd_attr_deregister_cpumask(struct genl_info *info){ cpumask_var_t mask; int rc;
if (!alloc_cpumask_var(&mask, GFP_KERNEL)) return -ENOMEM; rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], mask); if (rc < 0) goto out; rc = add_del_listener(info->snd_portid, mask, DEREGISTER);out: free_cpumask_var(mask); return rc;}
static size_t taskstats_packet_size(void){ size_t size;
size = nla_total_size(sizeof(u32)) + nla_total_size_64bit(sizeof(struct taskstats)) + nla_total_size(0);
return size;}
static int cmd_attr_pid(struct genl_info *info){ 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_new, *stats;
/* Pairs with smp_store_release() below. */ stats = smp_load_acquire(&sig->stats); if (stats || thread_group_empty(tsk)) return stats;
/* No problem if kmem_cache_zalloc() fails */ stats_new = kmem_cache_zalloc(taskstats_cache, GFP_KERNEL);
spin_lock_irq(&tsk->sighand->siglock); stats = sig->stats; if (!stats) { /* * Pairs with smp_store_release() above and order the * kmem_cache_zalloc(). */ smp_store_release(&sig->stats, stats_new); stats = stats_new; stats_new = NULL; } spin_unlock_irq(&tsk->sighand->siglock);
if (stats_new) kmem_cache_free(taskstats_cache, stats_new);
return 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 = raw_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, task_pid_nr_ns(tsk, &init_pid_ns)); if (!stats) goto err;
fill_stats(&init_user_ns, &init_pid_ns, tsk, stats); if (group_dead) stats->ac_flag |= AGROUP;
/* * 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, task_tgid_nr_ns(tsk, &init_pid_ns)); if (!stats) goto err;
memcpy(stats, tsk->signal->stats, sizeof(*stats)); stats->version = TASKSTATS_VERSION;
send: send_cpu_listeners(rep_skb, listeners); return;err: nlmsg_free(rep_skb);}
static const struct genl_ops taskstats_ops[] = { { .cmd = TASKSTATS_CMD_GET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .doit = taskstats_user_cmd, .policy = taskstats_cmd_get_policy, .maxattr = ARRAY_SIZE(taskstats_cmd_get_policy) - 1, .flags = GENL_ADMIN_PERM, }, { .cmd = CGROUPSTATS_CMD_GET, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .doit = cgroupstats_user_cmd, .policy = cgroupstats_cmd_get_policy, .maxattr = ARRAY_SIZE(cgroupstats_cmd_get_policy) - 1, },};
static struct genl_family family __ro_after_init = { .name = TASKSTATS_GENL_NAME, .version = TASKSTATS_GENL_VERSION, .module = THIS_MODULE, .ops = taskstats_ops, .n_ops = ARRAY_SIZE(taskstats_ops), .resv_start_op = CGROUPSTATS_CMD_GET + 1, .netnsok = true,};
/* 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;
family_registered = 1; pr_info("registered taskstats version %d\n", TASKSTATS_GENL_VERSION); return 0;}
/* * late initcall ensures initialization of statistics collection * mechanisms precedes initialization of the taskstats interface */late_initcall(taskstats_init);