6d41c675a5
The rtmutex specific deadlock detector predates lockdep coverage of rtmutex
and since commit f5694788ad ("rt_mutex: Add lockdep annotations") it
contains a lot of redundant functionality:
- lockdep will detect an potential deadlock before rtmutex-debug
has a chance to do so
- the deadlock debugging is restricted to rtmutexes which are not
associated to futexes and have an active waiter, which is covered by
lockdep already
Remove the redundant functionality and move actual deadlock WARN() into the
deadlock code path. The latter needs a seperate cleanup.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210326153943.320398604@linutronix.de
81 lines
2.0 KiB
C
81 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* RT-Mutexes: blocking mutual exclusion locks with PI support
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*
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* started by Ingo Molnar and Thomas Gleixner:
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*
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* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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* Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
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*
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* This code is based on the rt.c implementation in the preempt-rt tree.
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* Portions of said code are
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*
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* Copyright (C) 2004 LynuxWorks, Inc., Igor Manyilov, Bill Huey
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* Copyright (C) 2006 Esben Nielsen
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* Copyright (C) 2006 Kihon Technologies Inc.,
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* Steven Rostedt <rostedt@goodmis.org>
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*
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* See rt.c in preempt-rt for proper credits and further information
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*/
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#include <linux/sched.h>
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#include <linux/sched/rt.h>
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#include <linux/sched/debug.h>
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#include <linux/delay.h>
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#include <linux/export.h>
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#include <linux/spinlock.h>
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#include <linux/kallsyms.h>
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#include <linux/syscalls.h>
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#include <linux/interrupt.h>
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#include <linux/rbtree.h>
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#include <linux/fs.h>
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#include <linux/debug_locks.h>
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#include "rtmutex_common.h"
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void rt_mutex_debug_task_free(struct task_struct *task)
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{
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DEBUG_LOCKS_WARN_ON(!RB_EMPTY_ROOT(&task->pi_waiters.rb_root));
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DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
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}
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void debug_rt_mutex_lock(struct rt_mutex *lock)
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{
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}
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void debug_rt_mutex_unlock(struct rt_mutex *lock)
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{
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DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
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}
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void
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debug_rt_mutex_proxy_lock(struct rt_mutex *lock, struct task_struct *powner)
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{
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}
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void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
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{
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DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
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}
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void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
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{
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memset(waiter, 0x11, sizeof(*waiter));
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}
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void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
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{
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memset(waiter, 0x22, sizeof(*waiter));
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}
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void debug_rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key)
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{
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/*
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* Make sure we are not reinitializing a held lock:
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*/
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debug_check_no_locks_freed((void *)lock, sizeof(*lock));
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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lockdep_init_map(&lock->dep_map, name, key, 0);
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#endif
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}
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