mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
![Adrian Bunk](/assets/img/avatar_default.png)
We'd better not nlmsg_free on a pointer containing an undefined value (and without having anything allocated). Spotted by the Coverity checker. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Balbir Singh <balbir@linux.vnet.ibm> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
627 lines
14 KiB
C
627 lines
14 KiB
C
/*
|
|
* taskstats.c - Export per-task statistics to userland
|
|
*
|
|
* Copyright (C) Shailabh Nagar, IBM Corp. 2006
|
|
* (C) Balbir Singh, IBM Corp. 2006
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/taskstats_kern.h>
|
|
#include <linux/tsacct_kern.h>
|
|
#include <linux/delayacct.h>
|
|
#include <linux/cpumask.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/cgroupstats.h>
|
|
#include <linux/cgroup.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/file.h>
|
|
#include <net/genetlink.h>
|
|
#include <asm/atomic.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) = { 0 };
|
|
static int family_registered;
|
|
struct kmem_cache *taskstats_cache;
|
|
|
|
static struct genl_family family = {
|
|
.id = GENL_ID_GENERATE,
|
|
.name = TASKSTATS_GENL_NAME,
|
|
.version = TASKSTATS_GENL_VERSION,
|
|
.maxattr = TASKSTATS_CMD_ATTR_MAX,
|
|
};
|
|
|
|
static struct nla_policy taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1]
|
|
__read_mostly = {
|
|
[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 struct nla_policy
|
|
cgroupstats_cmd_get_policy[CGROUPSTATS_CMD_ATTR_MAX+1] __read_mostly = {
|
|
[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 = get_cpu_var(taskstats_seqnum)++;
|
|
put_cpu_var(taskstats_seqnum);
|
|
|
|
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, pid_t pid)
|
|
{
|
|
struct genlmsghdr *genlhdr = nlmsg_data(nlmsg_hdr(skb));
|
|
void *reply = genlmsg_data(genlhdr);
|
|
int rc;
|
|
|
|
rc = genlmsg_end(skb, reply);
|
|
if (rc < 0) {
|
|
nlmsg_free(skb);
|
|
return rc;
|
|
}
|
|
|
|
return genlmsg_unicast(skb, pid);
|
|
}
|
|
|
|
/*
|
|
* 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 rc, delcount = 0;
|
|
|
|
rc = genlmsg_end(skb, reply);
|
|
if (rc < 0) {
|
|
nlmsg_free(skb);
|
|
return;
|
|
}
|
|
|
|
rc = 0;
|
|
down_read(&listeners->sem);
|
|
list_for_each_entry(s, &listeners->list, list) {
|
|
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(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 int fill_pid(pid_t pid, struct task_struct *tsk,
|
|
struct taskstats *stats)
|
|
{
|
|
int rc = 0;
|
|
|
|
if (!tsk) {
|
|
rcu_read_lock();
|
|
tsk = find_task_by_pid(pid);
|
|
if (tsk)
|
|
get_task_struct(tsk);
|
|
rcu_read_unlock();
|
|
if (!tsk)
|
|
return -ESRCH;
|
|
} else
|
|
get_task_struct(tsk);
|
|
|
|
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(stats, tsk);
|
|
|
|
/* fill in extended acct fields */
|
|
xacct_add_tsk(stats, tsk);
|
|
|
|
/* Define err: label here if needed */
|
|
put_task_struct(tsk);
|
|
return rc;
|
|
|
|
}
|
|
|
|
static int fill_tgid(pid_t tgid, struct task_struct *first,
|
|
struct taskstats *stats)
|
|
{
|
|
struct task_struct *tsk;
|
|
unsigned long flags;
|
|
int rc = -ESRCH;
|
|
|
|
/*
|
|
* Add additional stats from live tasks except zombie thread group
|
|
* leaders who are already counted with the dead tasks
|
|
*/
|
|
rcu_read_lock();
|
|
if (!first)
|
|
first = find_task_by_pid(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));
|
|
|
|
tsk = first;
|
|
do {
|
|
if (tsk->exit_state)
|
|
continue;
|
|
/*
|
|
* Accounting subsystem can call its functions here to
|
|
* fill in relevant parts of struct taskstsats as follows
|
|
*
|
|
* per-task-foo(stats, tsk);
|
|
*/
|
|
delayacct_add_tsk(stats, tsk);
|
|
|
|
stats->nvcsw += tsk->nvcsw;
|
|
stats->nivcsw += tsk->nivcsw;
|
|
} while_each_thread(first, tsk);
|
|
|
|
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;
|
|
|
|
spin_lock_irqsave(&tsk->sighand->siglock, flags);
|
|
if (!tsk->signal->stats)
|
|
goto ret;
|
|
|
|
/*
|
|
* Each accounting subsystem calls its functions here to
|
|
* accumalate its per-task stats for tsk, into the per-tgid structure
|
|
*
|
|
* per-task-foo(tsk->signal->stats, tsk);
|
|
*/
|
|
delayacct_add_tsk(tsk->signal->stats, tsk);
|
|
ret:
|
|
spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
|
|
return;
|
|
}
|
|
|
|
static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd)
|
|
{
|
|
struct listener_list *listeners;
|
|
struct listener *s, *tmp;
|
|
unsigned int cpu;
|
|
cpumask_t mask = *maskp;
|
|
|
|
if (!cpus_subset(mask, cpu_possible_map))
|
|
return -EINVAL;
|
|
|
|
if (isadd == REGISTER) {
|
|
for_each_cpu_mask(cpu, mask) {
|
|
s = kmalloc_node(sizeof(struct listener), GFP_KERNEL,
|
|
cpu_to_node(cpu));
|
|
if (!s)
|
|
goto cleanup;
|
|
s->pid = pid;
|
|
INIT_LIST_HEAD(&s->list);
|
|
s->valid = 1;
|
|
|
|
listeners = &per_cpu(listener_array, cpu);
|
|
down_write(&listeners->sem);
|
|
list_add(&s->list, &listeners->list);
|
|
up_write(&listeners->sem);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Deregister or cleanup */
|
|
cleanup:
|
|
for_each_cpu_mask(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 0;
|
|
}
|
|
|
|
static int parse(struct nlattr *na, cpumask_t *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_strlcpy(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(skb, aggr);
|
|
if (!na)
|
|
goto err;
|
|
if (nla_put(skb, type, sizeof(pid), &pid) < 0)
|
|
goto err;
|
|
ret = nla_reserve(skb, TASKSTATS_TYPE_STATS, sizeof(struct taskstats));
|
|
if (!ret)
|
|
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;
|
|
struct file *file;
|
|
int fput_needed;
|
|
|
|
na = info->attrs[CGROUPSTATS_CMD_ATTR_FD];
|
|
if (!na)
|
|
return -EINVAL;
|
|
|
|
fd = nla_get_u32(info->attrs[CGROUPSTATS_CMD_ATTR_FD]);
|
|
file = fget_light(fd, &fput_needed);
|
|
if (!file)
|
|
return 0;
|
|
|
|
size = nla_total_size(sizeof(struct cgroupstats));
|
|
|
|
rc = prepare_reply(info, CGROUPSTATS_CMD_NEW, &rep_skb,
|
|
size);
|
|
if (rc < 0)
|
|
goto err;
|
|
|
|
na = nla_reserve(rep_skb, CGROUPSTATS_TYPE_CGROUP_STATS,
|
|
sizeof(struct cgroupstats));
|
|
stats = nla_data(na);
|
|
memset(stats, 0, sizeof(*stats));
|
|
|
|
rc = cgroupstats_build(stats, file->f_dentry);
|
|
if (rc < 0) {
|
|
nlmsg_free(rep_skb);
|
|
goto err;
|
|
}
|
|
|
|
rc = send_reply(rep_skb, info->snd_pid);
|
|
|
|
err:
|
|
fput_light(file, fput_needed);
|
|
return rc;
|
|
}
|
|
|
|
static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
|
|
{
|
|
int rc = 0;
|
|
struct sk_buff *rep_skb;
|
|
struct taskstats *stats;
|
|
size_t size;
|
|
cpumask_t mask;
|
|
|
|
rc = parse(info->attrs[TASKSTATS_CMD_ATTR_REGISTER_CPUMASK], &mask);
|
|
if (rc < 0)
|
|
return rc;
|
|
if (rc == 0)
|
|
return add_del_listener(info->snd_pid, &mask, REGISTER);
|
|
|
|
rc = parse(info->attrs[TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK], &mask);
|
|
if (rc < 0)
|
|
return rc;
|
|
if (rc == 0)
|
|
return add_del_listener(info->snd_pid, &mask, DEREGISTER);
|
|
|
|
/*
|
|
* Size includes space for nested attributes
|
|
*/
|
|
size = nla_total_size(sizeof(u32)) +
|
|
nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
|
|
|
|
rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
rc = -EINVAL;
|
|
if (info->attrs[TASKSTATS_CMD_ATTR_PID]) {
|
|
u32 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_pid(pid, NULL, stats);
|
|
if (rc < 0)
|
|
goto err;
|
|
} else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) {
|
|
u32 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_tgid(tgid, NULL, stats);
|
|
if (rc < 0)
|
|
goto err;
|
|
} else
|
|
goto err;
|
|
|
|
return send_reply(rep_skb, info->snd_pid);
|
|
err:
|
|
nlmsg_free(rep_skb);
|
|
return rc;
|
|
}
|
|
|
|
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 = nla_total_size(sizeof(u32)) +
|
|
nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
|
|
|
|
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_get_cpu_var(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;
|
|
|
|
rc = fill_pid(tsk->pid, tsk, stats);
|
|
if (rc < 0)
|
|
goto err;
|
|
|
|
/*
|
|
* 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,
|
|
};
|
|
|
|
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;
|
|
printk("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);
|