From: "Steven Rostedt (Red Hat)" <[email protected]> My tests found that if a task is running but not filtered when set_event_pid is modified, then it can still be traced.
Call on_each_cpu() to check if the current running task should be filtered and update the per cpu flags of tr->data appropriately. Signed-off-by: Steven Rostedt <[email protected]> --- kernel/trace/trace_events.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index ab07058e27c1..2b7fccd499c6 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1549,6 +1549,22 @@ static int max_pids(struct trace_pid_list *pid_list) return (PAGE_SIZE << pid_list->order) / sizeof(pid_t); } +static void ignore_task_cpu(void *data) +{ + struct trace_array *tr = data; + struct trace_pid_list *pid_list; + + /* + * This function is called by on_each_cpu() while the + * event_mutex is held. + */ + pid_list = rcu_dereference_protected(tr->filtered_pids, + mutex_is_locked(&event_mutex)); + + this_cpu_write(tr->trace_buffer.data->ignore_pid, + check_ignore_pid(pid_list, current)); +} + static ssize_t ftrace_event_pid_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) @@ -1711,6 +1727,12 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, tr, INT_MAX); register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr, 0); + + /* + * Ignoring of pids is done at task switch. But we have to + * check for those tasks that are currently running. + */ + on_each_cpu(ignore_task_cpu, tr, 1); } mutex_unlock(&event_mutex); -- 2.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
