From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt
---
kernel/kernel/locking/rtmutex-debug.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 102 insertions(+), 0 deletions(-)
diff --git a/kernel/kernel/locking/rtmutex-debug.c b/kernel/kernel/locking/rtmutex-debug.c
index fb15010..36e6910 100644
--- a/kernel/kernel/locking/rtmutex-debug.c
+++ b/kernel/kernel/locking/rtmutex-debug.c
@@ -32,10 +32,108 @@
#include "rtmutex_common.h"
+static void printk_task(struct task_struct *p)
+{
+ if (p)
+ printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), p, p->prio);
+ else
+ printk("<none>");
+}
+
+static void printk_lock(struct rt_mutex *lock, int print_owner)
+{
+ if (lock->name)
+ printk(" [%p] {%s}\n",
+ lock, lock->name);
+ else
+ printk(" [%p] {%s:%d}\n",
+ lock, lock->file, lock->line);
+
+ if (print_owner && rt_mutex_owner(lock)) {
+ printk(".. ->owner: %p\n", lock->owner);
+ printk(".. held by: ");
+ printk_task(rt_mutex_owner(lock));
+ printk("\n");
+ }
+}
+
void rt_mutex_debug_task_free(struct task_struct *task)
{
DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root));
DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
+}
+
+/*
+ * We fill out the fields in the waiter to store the information about
+ * the deadlock. We print when we return. act_waiter can be NULL in
+ * case of a remove waiter operation.
+ */
+void debug_rt_mutex_deadlock(enum rtmutex_chainwalk chwalk,
+ struct rt_mutex_waiter *act_waiter,
+ struct rt_mutex *lock)
+{
+ struct task_struct *task;
+
+ if (!debug_locks || chwalk == RT_MUTEX_FULL_CHAINWALK || !act_waiter)
+ return;
+
+ task = rt_mutex_owner(act_waiter->lock);
+ if (task && task != current) {
+ act_waiter->deadlock_task_pid = get_pid(task_pid(task));
+ act_waiter->deadlock_lock = lock;
+ }
+}
+
+void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
+{
+ struct task_struct *task;
+
+ if (!waiter->deadlock_lock || !debug_locks)
+ return;
+
+ rcu_read_lock();
+ task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID);
+ if (!task) {
+ rcu_read_unlock();
+ return;
+ }
+
+ if (!debug_locks_off()) {
+ rcu_read_unlock();
+ return;
+ }
+
+ pr_warn("\n");
+ pr_warn("============================================\n");
+ pr_warn("WARNING: circular locking deadlock detected!\n");
+ pr_warn("%s\n", print_tainted());
+ pr_warn("--------------------------------------------\n");
+ printk("%s/%d is deadlocking current task %s/%d\n\n",
+ task->comm, task_pid_nr(task),
+ current->comm, task_pid_nr(current));
+
+ printk("\n1) %s/%d is trying to acquire this lock:\n",
+ current->comm, task_pid_nr(current));
+ printk_lock(waiter->lock, 1);
+
+ printk("\n2) %s/%d is blocked on this lock:\n",
+ task->comm, task_pid_nr(task));
+ printk_lock(waiter->deadlock_lock, 1);
+
+ debug_show_held_locks(current);
+ debug_show_held_locks(task);
+
+ printk("\n%s/%d's [blocked] stackdump:\n\n",
+ task->comm, task_pid_nr(task));
+ show_stack(task, NULL, KERN_DEFAULT);
+ printk("\n%s/%d's [current] stackdump:\n\n",
+ 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");
}
void debug_rt_mutex_lock(struct rt_mutex *lock)
@@ -60,10 +158,12 @@
void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
{
memset(waiter, 0x11, sizeof(*waiter));
+ waiter->deadlock_task_pid = NULL;
}
void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
{
+ put_pid(waiter->deadlock_task_pid);
memset(waiter, 0x22, sizeof(*waiter));
}
@@ -73,8 +173,10 @@
* Make sure we are not reinitializing a held lock:
*/
debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+ lock->name = name;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
lockdep_init_map(&lock->dep_map, name, key, 0);
#endif
}
+
--
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