Don't operate with pid_t in rtmutex tester
The proper behavior to store task's pid and get this task later is to get the
struct pid pointer and get the task with the pid_task() call.
Make it for rt_mutex_waiter->deadlock_task_pid field.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/rtmutex-debug.c b/kernel/rtmutex-debug.c
index 56d73cb..5fcb4fe 100644
--- a/kernel/rtmutex-debug.c
+++ b/kernel/rtmutex-debug.c
@@ -130,7 +130,7 @@
task = rt_mutex_owner(act_waiter->lock);
if (task && task != current) {
- act_waiter->deadlock_task_pid = task->pid;
+ act_waiter->deadlock_task_pid = get_pid(task_pid(task));
act_waiter->deadlock_lock = lock;
}
}
@@ -142,9 +142,12 @@
if (!waiter->deadlock_lock || !rt_trace_on)
return;
- task = find_task_by_pid(waiter->deadlock_task_pid);
- if (!task)
+ rcu_read_lock();
+ task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID);
+ if (!task) {
+ rcu_read_unlock();
return;
+ }
TRACE_OFF_NOLOCK();
@@ -173,6 +176,7 @@
current->comm, task_pid_nr(current));
dump_stack();
debug_show_all_locks();
+ rcu_read_unlock();
printk("[ turning off deadlock detection."
"Please report this trace. ]\n\n");
@@ -203,10 +207,12 @@
memset(waiter, 0x11, sizeof(*waiter));
plist_node_init(&waiter->list_entry, MAX_PRIO);
plist_node_init(&waiter->pi_list_entry, MAX_PRIO);
+ waiter->deadlock_task_pid = NULL;
}
void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
{
+ put_pid(waiter->deadlock_task_pid);
TRACE_WARN_ON(!plist_node_empty(&waiter->list_entry));
TRACE_WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
TRACE_WARN_ON(waiter->task);
diff --git a/kernel/rtmutex_common.h b/kernel/rtmutex_common.h
index 2d3b835..e124bf5 100644
--- a/kernel/rtmutex_common.h
+++ b/kernel/rtmutex_common.h
@@ -51,7 +51,7 @@
struct rt_mutex *lock;
#ifdef CONFIG_DEBUG_RT_MUTEXES
unsigned long ip;
- pid_t deadlock_task_pid;
+ struct pid *deadlock_task_pid;
struct rt_mutex *deadlock_lock;
#endif
};