1 files changed, 104 insertions, 68 deletions

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 11281d5..c8231fb 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -175,22 +175,8 @@ static void send_cpu_listeners(struct sk_buff *skb,
 	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
@@ -209,17 +195,27 @@ static int fill_pid(pid_t pid, struct task_struct *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_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;
 
@@ -228,8 +224,7 @@ static int fill_tgid(pid_t tgid, struct task_struct *first,
 	 * 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;
@@ -268,7 +263,6 @@ out:
 	return rc;
 }
 
-
 static void fill_tgid_exit(struct task_struct *tsk)
 {
 	unsigned long flags;
@@ -360,6 +354,12 @@ static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
 	struct nlattr *na, *ret;
 	int aggr;
 
+	/* If we don't pad, we end up with alignment on a 4 byte boundary.
+	 * This causes lots of runtime warnings on systems requiring 8 byte
+	 * alignment */
+	u32 pids[2] = { pid, 0 };
+	int pid_size = ALIGN(sizeof(pid), sizeof(long));
+
 	aggr = (type == TASKSTATS_TYPE_PID)
 			? TASKSTATS_TYPE_AGGR_PID
 			: TASKSTATS_TYPE_AGGR_TGID;
@@ -367,7 +367,7 @@ static struct taskstats *mk_reply(struct sk_buff *skb, int type, u32 pid)
 	na = nla_nest_start(skb, aggr);
 	if (!na)
 		goto err;
-	if (nla_put(skb, type, sizeof(pid), &pid) < 0)
+	if (nla_put(skb, type, pid_size, pids) < 0)
 		goto err;
 	ret = nla_reserve(skb, TASKSTATS_TYPE_STATS, sizeof(struct taskstats));
 	if (!ret)
@@ -424,39 +424,46 @@ err:
 	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 int cmd_attr_pid(struct genl_info *info)
+{
+	struct taskstats *stats;
+	struct sk_buff *rep_skb;
+	size_t size;
+	u32 pid;
+	int rc;
 
-	/*
-	 * Size includes space for nested attributes
-	 */
 	size = nla_total_size(sizeof(u32)) +
 		nla_total_size(sizeof(struct taskstats)) + nla_total_size(0);
 
@@ -465,33 +472,64 @@ free_return_rc:
 		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 = 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;
+	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;
@@ -555,9 +593,7 @@ void taskstats_exit(struct task_struct *tsk, int group_dead)
 	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