Beispiel #1
0
static inline void __lock_kernel(void)
{
	preempt_disable();
	if (unlikely(!__raw_spin_trylock(&kernel_flag))) {
		/*
		 * If preemption was disabled even before this
		 * was called, there's nothing we can be polite
		 * about - just spin.
		 */
		if (preempt_count() > 1) {
			__raw_spin_lock(&kernel_flag);
			return;
		}

		/*
		 * Otherwise, let's wait for the kernel lock
		 * with preemption enabled..
		 */
		do {
			preempt_enable();
			while (spin_is_locked(&kernel_flag))
				cpu_relax();
			preempt_disable();
		} while (!__raw_spin_trylock(&kernel_flag));
	}
}
Beispiel #2
0
void _raw_spin_lock(spinlock_t *lock)
{
	debug_spin_lock_before(lock);
	if (unlikely(!__raw_spin_trylock(&lock->raw_lock)))
		__spin_lock_debug(lock);
	debug_spin_lock_after(lock);
}
Beispiel #3
0
static void __spin_lock_debug(spinlock_t *lock)
{
	u64 i;
	u64 loops = loops_per_jiffy * HZ;
	int print_once = 1;

	for (;;) {
		for (i = 0; i < loops; i++) {
			if (__raw_spin_trylock(&lock->raw_lock))
				return;
			__delay(1);
		}
		/* lockup suspected: */
		if (print_once) {
			print_once = 0;
			printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, "
					"%s/%d, %p\n",
				raw_smp_processor_id(), current->comm,
				task_pid_nr(current), lock);
			dump_stack();
#ifdef CONFIG_SMP
			trigger_all_cpu_backtrace();
#endif
		}
	}
}
Beispiel #4
0
unsigned __kprobes long oops_begin(void)
{
	int cpu;
	unsigned long flags;

	
	trace_hw_branch_oops();

	oops_enter();

	
	raw_local_irq_save(flags);
	cpu = smp_processor_id();
	if (!__raw_spin_trylock(&die_lock)) {
		if (cpu == die_owner)
			;
		else
			__raw_spin_lock(&die_lock);
	}
	die_nest_count++;
	die_owner = cpu;
	console_verbose();
	bust_spinlocks(1);
	return flags;
}
Beispiel #5
0
unsigned __kprobes long oops_begin(void)
{
	int cpu;
	unsigned long flags;

	/* notify the hw-branch tracer so it may disable tracing and
	   add the last trace to the trace buffer -
	   the earlier this happens, the more useful the trace. */
	trace_hw_branch_oops();

	oops_enter();

	/* racy, but better than risking deadlock. */
	raw_local_irq_save(flags);
	cpu = smp_processor_id();
	if (!__raw_spin_trylock(&die_lock)) {
		if (cpu == die_owner)
			/* nested oops. should stop eventually */;
		else
			__raw_spin_lock(&die_lock);
	}
	die_nest_count++;
	die_owner = cpu;
	console_verbose();
	bust_spinlocks(1);
	return flags;
}
Beispiel #6
0
/*
 * Acquire/release the underlying lock from the scheduler.
 *
 * This is called with preemption disabled, and should
 * return an error value if it cannot get the lock and
 * TIF_NEED_RESCHED gets set.
 *
 * If it successfully gets the lock, it should increment
 * the preemption count like any spinlock does.
 *
 * (This works on UP too - _raw_spin_trylock will never
 * return false in that case)
 */
int __lockfunc __reacquire_kernel_lock(void)
{
	local_irq_enable();
	while (!__raw_spin_trylock(&kernel_flag)) {
		if (test_thread_flag(TIF_NEED_RESCHED))
			return -EAGAIN;
		cpu_relax();
	}
	local_irq_disable();
	preempt_disable();
	return 0;
}
Beispiel #7
0
int _raw_spin_trylock(spinlock_t *lock)
{
	int ret = __raw_spin_trylock(&lock->raw_lock);

	if (ret)
		debug_spin_lock_after(lock);
#ifndef CONFIG_SMP
	/*
	 * Must not happen on UP:
	 */
	SPIN_BUG_ON(!ret, lock, "trylock failure on UP");
#endif
	return ret;
}
Beispiel #8
0
static void __spin_lock_debug(spinlock_t *lock)
{
	int print_once = 1;
	u64 i;

	for (;;) {
		for (i = 0; i < loops_per_jiffy * HZ; i++) {
			if (__raw_spin_trylock(&lock->raw_lock))
				return;
		}
		/* lockup suspected: */
		if (print_once) {
			print_once = 0;
			printk(KERN_EMERG "BUG: spinlock lockup on CPU#%d, "
					"%s/%d, %p (%s)\n",
				raw_smp_processor_id(), current->comm,
				current->pid, lock, print_tainted());
			dump_stack();
		}
	}
}
Beispiel #9
0
unsigned __kprobes long oops_begin(void)
{
	int cpu;
	unsigned long flags;

	oops_enter();

	/* racy, but better than risking deadlock. */
	raw_local_irq_save(flags);
	cpu = smp_processor_id();
	if (!__raw_spin_trylock(&die_lock)) {
		if (cpu == die_owner)
			/* nested oops. should stop eventually */;
		else
			__raw_spin_lock(&die_lock);
	}
	die_nest_count++;
	die_owner = cpu;
	console_verbose();
	bust_spinlocks(1);
	return flags;
}
Beispiel #10
0
int __lockfunc _raw_spin_trylock(raw_spinlock_t *lock)
{
	return __raw_spin_trylock(lock);
}