Commit 408894ee authored by Ingo Molnar's avatar Ingo Molnar Committed by Ingo Molnar

[PATCH] mutex subsystem, debugging code

mutex implementation - add debugging code.
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarArjan van de Ven <arjan@infradead.org>
parent f3f54ffa
#ifndef __LINUX_MUTEX_DEBUG_H
#define __LINUX_MUTEX_DEBUG_H
/*
* Mutexes - debugging helpers:
*/
#define __DEBUG_MUTEX_INITIALIZER(lockname) \
, .held_list = LIST_HEAD_INIT(lockname.held_list), \
.name = #lockname , .magic = &lockname
#define mutex_init(sem) __mutex_init(sem, __FUNCTION__)
extern void FASTCALL(mutex_destroy(struct mutex *lock));
extern void mutex_debug_show_all_locks(void);
extern void mutex_debug_show_held_locks(struct task_struct *filter);
extern void mutex_debug_check_no_locks_held(struct task_struct *task);
extern void mutex_debug_check_no_locks_freed(const void *from, const void *to);
#endif
......@@ -817,6 +817,11 @@ struct task_struct {
/* Protection of proc_dentry: nesting proc_lock, dcache_lock, write_lock_irq(&tasklist_lock); */
spinlock_t proc_lock;
#ifdef CONFIG_DEBUG_MUTEXES
/* mutex deadlock detection */
struct mutex_waiter *blocked_on;
#endif
/* journalling filesystem info */
void *journal_info;
......
......@@ -9,6 +9,7 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
rcupdate.o intermodule.o extable.o params.o posix-timers.o \
kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o
obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o
obj-$(CONFIG_FUTEX) += futex.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += cpu.o spinlock.o
......
......@@ -979,6 +979,10 @@ static task_t *copy_process(unsigned long clone_flags,
}
#endif
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif
p->tgid = p->pid;
if (clone_flags & CLONE_THREAD)
p->tgid = current->tgid;
......
This diff is collapsed.
/*
* Mutexes: blocking mutual exclusion locks
*
* started by Ingo Molnar:
*
* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*
* This file contains mutex debugging related internal declarations,
* prototypes and inline functions, for the CONFIG_DEBUG_MUTEXES case.
* More details are in kernel/mutex-debug.c.
*/
extern spinlock_t debug_mutex_lock;
extern struct list_head debug_mutex_held_locks;
extern int debug_mutex_on;
/*
* In the debug case we carry the caller's instruction pointer into
* other functions, but we dont want the function argument overhead
* in the nondebug case - hence these macros:
*/
#define __IP_DECL__ , unsigned long ip
#define __IP__ , ip
#define __RET_IP__ , (unsigned long)__builtin_return_address(0)
/*
* This must be called with lock->wait_lock held.
*/
extern void debug_mutex_set_owner(struct mutex *lock,
struct thread_info *new_owner __IP_DECL__);
static inline void debug_mutex_clear_owner(struct mutex *lock)
{
lock->owner = NULL;
}
extern void debug_mutex_init_waiter(struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
struct mutex_waiter *waiter);
extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
extern void debug_mutex_add_waiter(struct mutex *lock,
struct mutex_waiter *waiter,
struct thread_info *ti __IP_DECL__);
extern void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct thread_info *ti);
extern void debug_mutex_unlock(struct mutex *lock);
extern void debug_mutex_init(struct mutex *lock, const char *name);
#define debug_spin_lock(lock) \
do { \
local_irq_disable(); \
if (debug_mutex_on) \
spin_lock(lock); \
} while (0)
#define debug_spin_unlock(lock) \
do { \
if (debug_mutex_on) \
spin_unlock(lock); \
local_irq_enable(); \
preempt_check_resched(); \
} while (0)
#define debug_spin_lock_save(lock, flags) \
do { \
local_irq_save(flags); \
if (debug_mutex_on) \
spin_lock(lock); \
} while (0)
#define debug_spin_lock_restore(lock, flags) \
do { \
if (debug_mutex_on) \
spin_unlock(lock); \
local_irq_restore(flags); \
preempt_check_resched(); \
} while (0)
#define spin_lock_mutex(lock) \
do { \
struct mutex *l = container_of(lock, struct mutex, wait_lock); \
\
DEBUG_WARN_ON(in_interrupt()); \
debug_spin_lock(&debug_mutex_lock); \
spin_lock(lock); \
DEBUG_WARN_ON(l->magic != l); \
} while (0)
#define spin_unlock_mutex(lock) \
do { \
spin_unlock(lock); \
debug_spin_unlock(&debug_mutex_lock); \
} while (0)
#define DEBUG_OFF() \
do { \
if (debug_mutex_on) { \
debug_mutex_on = 0; \
console_verbose(); \
if (spin_is_locked(&debug_mutex_lock)) \
spin_unlock(&debug_mutex_lock); \
} \
} while (0)
#define DEBUG_BUG() \
do { \
if (debug_mutex_on) { \
DEBUG_OFF(); \
BUG(); \
} \
} while (0)
#define DEBUG_WARN_ON(c) \
do { \
if (unlikely(c && debug_mutex_on)) { \
DEBUG_OFF(); \
WARN_ON(1); \
} \
} while (0)
# define DEBUG_BUG_ON(c) \
do { \
if (unlikely(c)) \
DEBUG_BUG(); \
} while (0)
#ifdef CONFIG_SMP
# define SMP_DEBUG_WARN_ON(c) DEBUG_WARN_ON(c)
# define SMP_DEBUG_BUG_ON(c) DEBUG_BUG_ON(c)
#else
# define SMP_DEBUG_WARN_ON(c) do { } while (0)
# define SMP_DEBUG_BUG_ON(c) do { } while (0)
#endif
......@@ -95,6 +95,14 @@ config DEBUG_PREEMPT
if kernel code uses it in a preemption-unsafe way. Also, the kernel
will detect preemption count underflows.
config DEBUG_MUTEXES
bool "Mutex debugging, deadlock detection"
default y
depends on DEBUG_KERNEL
help
This allows mutex semantics violations and mutex related deadlocks
(lockups) to be detected and reported automatically.
config DEBUG_SPINLOCK
bool "Spinlock debugging"
depends on DEBUG_KERNEL
......
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