diff options
| -rw-r--r-- | kernel/taskstats.c | 59 |
1 files changed, 24 insertions, 35 deletions
diff --git a/kernel/taskstats.c b/kernel/taskstats.c index b2efda94615..b724aeea544 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -174,21 +174,19 @@ static void send_cpu_listeners(struct sk_buff *skb, unsigned int cpu) up_write(&listeners->sem); } -static int fill_pid(pid_t pid, struct task_struct *pidtsk, +static int fill_pid(pid_t pid, struct task_struct *tsk, struct taskstats *stats) { int rc = 0; - struct task_struct *tsk = pidtsk; - if (!pidtsk) { - read_lock(&tasklist_lock); + if (!tsk) { + rcu_read_lock(); tsk = find_task_by_pid(pid); - if (!tsk) { - read_unlock(&tasklist_lock); + if (tsk) + get_task_struct(tsk); + rcu_read_unlock(); + if (!tsk) return -ESRCH; - } - get_task_struct(tsk); - read_unlock(&tasklist_lock); } else get_task_struct(tsk); @@ -214,40 +212,28 @@ static int fill_pid(pid_t pid, struct task_struct *pidtsk, } -static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, +static int fill_tgid(pid_t tgid, struct task_struct *first, struct taskstats *stats) { - struct task_struct *tsk, *first; + 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 */ - first = tgidtsk; - if (!first) { - read_lock(&tasklist_lock); + rcu_read_lock(); + if (!first) first = find_task_by_pid(tgid); - if (!first) { - read_unlock(&tasklist_lock); - return -ESRCH; - } - get_task_struct(first); - read_unlock(&tasklist_lock); - } else - get_task_struct(first); + if (!first || !lock_task_sighand(first, &flags)) + goto out; - tsk = first; - read_lock(&tasklist_lock); - /* Start with stats from dead tasks */ - if (first->sighand) { - spin_lock_irqsave(&first->sighand->siglock, flags); - if (first->signal->stats) - memcpy(stats, first->signal->stats, sizeof(*stats)); - spin_unlock_irqrestore(&first->sighand->siglock, flags); - } + if (first->signal->stats) + memcpy(stats, first->signal->stats, sizeof(*stats)); + tsk = first; do { if (tsk->exit_state == EXIT_ZOMBIE && thread_group_leader(tsk)) continue; @@ -260,15 +246,18 @@ static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, delayacct_add_tsk(stats, tsk); } while_each_thread(first, tsk); - read_unlock(&tasklist_lock); - stats->version = TASKSTATS_VERSION; + unlock_task_sighand(first, &flags); + rc = 0; +out: + rcu_read_unlock(); + + stats->version = TASKSTATS_VERSION; /* * Accounting subsytems can also add calls here to modify * fields of taskstats. */ - put_task_struct(first); - return 0; + return rc; } |