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Diffstat (limited to 'kernel/hung_task.c')
-rw-r--r--kernel/hung_task.c76
1 files changed, 65 insertions, 11 deletions
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index dc898ec93463..8708a1205f82 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -22,6 +22,8 @@
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/sched/sysctl.h>
+#include <linux/hung_task.h>
+#include <linux/rwsem.h>
#include <trace/events/sched.h>
@@ -98,30 +100,82 @@ static struct notifier_block panic_block = {
static void debug_show_blocker(struct task_struct *task)
{
struct task_struct *g, *t;
- unsigned long owner;
- struct mutex *lock;
+ unsigned long owner, blocker, blocker_type;
+ const char *rwsem_blocked_by, *rwsem_blocked_as;
RCU_LOCKDEP_WARN(!rcu_read_lock_held(), "No rcu lock held");
- lock = READ_ONCE(task->blocker_mutex);
- if (!lock)
+ blocker = READ_ONCE(task->blocker);
+ if (!blocker)
return;
- owner = mutex_get_owner(lock);
+ blocker_type = hung_task_get_blocker_type(blocker);
+
+ switch (blocker_type) {
+ case BLOCKER_TYPE_MUTEX:
+ owner = mutex_get_owner(hung_task_blocker_to_lock(blocker));
+ break;
+ case BLOCKER_TYPE_SEM:
+ owner = sem_last_holder(hung_task_blocker_to_lock(blocker));
+ break;
+ case BLOCKER_TYPE_RWSEM_READER:
+ case BLOCKER_TYPE_RWSEM_WRITER:
+ owner = (unsigned long)rwsem_owner(
+ hung_task_blocker_to_lock(blocker));
+ rwsem_blocked_as = (blocker_type == BLOCKER_TYPE_RWSEM_READER) ?
+ "reader" : "writer";
+ rwsem_blocked_by = is_rwsem_reader_owned(
+ hung_task_blocker_to_lock(blocker)) ?
+ "reader" : "writer";
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
+
+
if (unlikely(!owner)) {
- pr_err("INFO: task %s:%d is blocked on a mutex, but the owner is not found.\n",
- task->comm, task->pid);
+ switch (blocker_type) {
+ case BLOCKER_TYPE_MUTEX:
+ pr_err("INFO: task %s:%d is blocked on a mutex, but the owner is not found.\n",
+ task->comm, task->pid);
+ break;
+ case BLOCKER_TYPE_SEM:
+ pr_err("INFO: task %s:%d is blocked on a semaphore, but the last holder is not found.\n",
+ task->comm, task->pid);
+ break;
+ case BLOCKER_TYPE_RWSEM_READER:
+ case BLOCKER_TYPE_RWSEM_WRITER:
+ pr_err("INFO: task %s:%d is blocked on an rw-semaphore, but the owner is not found.\n",
+ task->comm, task->pid);
+ break;
+ }
return;
}
/* Ensure the owner information is correct. */
for_each_process_thread(g, t) {
- if ((unsigned long)t == owner) {
+ if ((unsigned long)t != owner)
+ continue;
+
+ switch (blocker_type) {
+ case BLOCKER_TYPE_MUTEX:
pr_err("INFO: task %s:%d is blocked on a mutex likely owned by task %s:%d.\n",
- task->comm, task->pid, t->comm, t->pid);
- sched_show_task(t);
- return;
+ task->comm, task->pid, t->comm, t->pid);
+ break;
+ case BLOCKER_TYPE_SEM:
+ pr_err("INFO: task %s:%d blocked on a semaphore likely last held by task %s:%d\n",
+ task->comm, task->pid, t->comm, t->pid);
+ break;
+ case BLOCKER_TYPE_RWSEM_READER:
+ case BLOCKER_TYPE_RWSEM_WRITER:
+ pr_err("INFO: task %s:%d <%s> blocked on an rw-semaphore likely owned by task %s:%d <%s>\n",
+ task->comm, task->pid, rwsem_blocked_as, t->comm,
+ t->pid, rwsem_blocked_by);
+ break;
}
+ sched_show_task(t);
+ return;
}
}
#else