return -ENOMEM;
if (!info) {
- int seq = get_cpu_var(taskstats_seqnum)++;
- put_cpu_var(taskstats_seqnum);
+ int seq = this_cpu_inc_return(taskstats_seqnum) - 1;
reply = genlmsg_put(skb, 0, seq, &family, 0, cmd);
} else
up_write(&listeners->sem);
}
-static int fill_pid(pid_t pid, struct task_struct *tsk,
- struct taskstats *stats)
+static void fill_stats(struct task_struct *tsk, struct taskstats *stats)
{
- int rc = 0;
-
- if (!tsk) {
- rcu_read_lock();
- tsk = find_task_by_vpid(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 extended acct fields */
xacct_add_tsk(stats, tsk);
+}
- /* Define err: label here if needed */
- put_task_struct(tsk);
- return rc;
+static int fill_stats_for_pid(pid_t pid, struct taskstats *stats)
+{
+ struct task_struct *tsk;
+ rcu_read_lock();
+ tsk = find_task_by_vpid(pid);
+ if (tsk)
+ get_task_struct(tsk);
+ rcu_read_unlock();
+ if (!tsk)
+ return -ESRCH;
+ fill_stats(tsk, stats);
+ put_task_struct(tsk);
+ return 0;
}
-static int fill_tgid(pid_t tgid, struct task_struct *first,
- struct taskstats *stats)
+static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
{
- struct task_struct *tsk;
+ struct task_struct *tsk, *first;
unsigned long flags;
int rc = -ESRCH;
* leaders who are already counted with the dead tasks
*/
rcu_read_lock();
- if (!first)
- first = find_task_by_vpid(tgid);
+ first = find_task_by_vpid(tgid);
if (!first || !lock_task_sighand(first, &flags))
goto out;
return rc;
}
-
static void fill_tgid_exit(struct task_struct *tsk)
{
unsigned long flags;
static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
{
struct listener_list *listeners;
- struct listener *s, *tmp;
+ struct listener *s, *tmp, *s2;
unsigned int cpu;
if (!cpumask_subset(mask, cpu_possible_mask))
return -EINVAL;
+ s = NULL;
if (isadd == REGISTER) {
for_each_cpu(cpu, mask) {
- s = kmalloc_node(sizeof(struct listener), GFP_KERNEL,
- cpu_to_node(cpu));
+ if (!s)
+ s = kmalloc_node(sizeof(struct listener),
+ GFP_KERNEL, cpu_to_node(cpu));
if (!s)
goto cleanup;
s->pid = pid;
listeners = &per_cpu(listener_array, cpu);
down_write(&listeners->sem);
+ list_for_each_entry_safe(s2, tmp, &listeners->list, list) {
+ if (s2->pid == pid)
+ goto next_cpu;
+ }
list_add(&s->list, &listeners->list);
+ s = NULL;
+next_cpu:
up_write(&listeners->sem);
}
+ kfree(s);
return 0;
}
return ret;
}
+#if defined(CONFIG_64BIT) && !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+#define TASKSTATS_NEEDS_PADDING 1
+#endif
+
static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
{
struct nlattr *na, *ret;
? TASKSTATS_TYPE_AGGR_PID
: TASKSTATS_TYPE_AGGR_TGID;
+ /*
+ * The taskstats structure is internally aligned on 8 byte
+ * boundaries but the layout of the aggregrate reply, with
+ * two NLA headers and the pid (each 4 bytes), actually
+ * force the entire structure to be unaligned. This causes
+ * the kernel to issue unaligned access warnings on some
+ * architectures like ia64. Unfortunately, some software out there
+ * doesn't properly unroll the NLA packet and assumes that the start
+ * of the taskstats structure will always be 20 bytes from the start
+ * of the netlink payload. Aligning the start of the taskstats
+ * structure breaks this software, which we don't want. So, for now
+ * the alignment only happens on architectures that require it
+ * and those users will have to update to fixed versions of those
+ * packages. Space is reserved in the packet only when needed.
+ * This ifdef should be removed in several years e.g. 2012 once
+ * we can be confident that fixed versions are installed on most
+ * systems. We add the padding before the aggregate since the
+ * aggregate is already a defined type.
+ */
+#ifdef TASKSTATS_NEEDS_PADDING
+ if (nla_put(skb, TASKSTATS_TYPE_NULL, 0, NULL) < 0)
+ goto err;
+#endif
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));
return rc;
}
-static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info)
+static int cmd_attr_register_cpumask(struct genl_info *info)
{
- int rc;
- struct sk_buff *rep_skb;
- struct taskstats *stats;
- size_t size;
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 free_return_rc;
- if (rc == 0) {
- rc = add_del_listener(info->snd_pid, mask, REGISTER);
- goto free_return_rc;
- }
+ goto out;
+ rc = add_del_listener(info->snd_pid, 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 free_return_rc;
- if (rc == 0) {
- rc = add_del_listener(info->snd_pid, mask, DEREGISTER);
-free_return_rc:
- free_cpumask_var(mask);
- return rc;
- }
+ goto out;
+ rc = add_del_listener(info->snd_pid, mask, DEREGISTER);
+out:
free_cpumask_var(mask);
+ return rc;
+}
+
+static size_t taskstats_packet_size(void)
+{
+ size_t size;
- /*
- * Size includes space for nested attributes
- */
size = nla_total_size(sizeof(u32)) +
nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
+#ifdef TASKSTATS_NEEDS_PADDING
+ size += nla_total_size(0); /* Padding for alignment */
+#endif
+ 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;
- 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
+ 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;
/*
* Size includes space for nested attributes
*/
- size = nla_total_size(sizeof(u32)) +
- nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
+ size = taskstats_packet_size();
is_thread_group = !!taskstats_tgid_alloc(tsk);
if (is_thread_group) {
fill_tgid_exit(tsk);
}
- listeners = &__raw_get_cpu_var(listener_array);
+ listeners = __this_cpu_ptr(&listener_array);
if (list_empty(&listeners->list))
return;
if (!stats)
goto err;
- rc = fill_pid(-1, tsk, stats);
- if (rc < 0)
- goto err;
+ fill_stats(tsk, stats);
/*
* Doesn't matter if tsk is the leader or the last group member leaving
projects / linux-flexiantxendom0-natty.git / blobdiff