Ejemplo n.º 1
0
/*****************************************************************************
函数名称  : mlog_print
功能描述  :
输入参数  :
输出参数  :
返 回 值  : No
修改历史  :
*****************************************************************************/
asmlinkage void mlog_print(char *module, mlog_lv_eum loglv,const char *fmt,...)
{
    int printed_len = 0;
    unsigned long flags;
    char *p ;
    unsigned wake_up = 0;
    va_list args;
    struct timespec uptime;

    if((NULL == module) || ( NULL == fmt))
    {
        return;
    }
    /*PROC未创建成功,返回*/	
    if(FALSE == proc_init_ok)
    {
        return;
    }

    local_irq_save(flags);
    if (!raw_spin_trylock(&mlog_log_buf_lock))
    {
        local_irq_restore(flags);
        return;
    }
    do_posix_clock_monotonic_gettime(&uptime);
    monotonic_to_bootbased(&uptime);
    snprintf(print_buf, MLOG_MAX_HEAD_LEN , "[%011lu][%s][%s]:", 
        ((uptime.tv_sec * 1000) + (uptime.tv_nsec / 1000000)),/*将秒和纳秒转换成毫秒*/
        module,mlog_get_log_lv_string(loglv));
    printed_len = strlen(print_buf);
    va_start(args, fmt);
    vsnprintf(print_buf + printed_len , MLOG_MAX_LOG_LEN - 1, fmt, args);
    printed_len = strlen(print_buf);
    va_end(args);
    //若调用者log行尾未未增加换行,帮其增加
    if('\n' != print_buf[printed_len - 1])
    {
        print_buf[printed_len] = '\n';
        printed_len++;
        print_buf[printed_len] = '\0';
    }
    printed_len++;

    p = print_buf;
    for (; *p; p++) {
        mlog_log_write_char(*p);
    }

    wake_up = (log_wr_off == log_rd_off);
    if (!wake_up) {
         wake_up_interruptible(&mlog_log_wait);
    }

    raw_spin_unlock(&mlog_log_buf_lock);
    local_irq_restore(flags);

    return;
}
Ejemplo n.º 2
0
/* Check if this is a system NMI event */
static int uv_check_nmi(struct uv_hub_nmi_s *hub_nmi)
{
	int cpu = smp_processor_id();
	int nmi = 0;

	local64_inc(&uv_nmi_count);
	uv_cpu_nmi.queries++;

	do {
		nmi = atomic_read(&hub_nmi->in_nmi);
		if (nmi)
			break;

		if (raw_spin_trylock(&hub_nmi->nmi_lock)) {

			/* check hub MMR NMI flag */
			if (uv_nmi_test_mmr(hub_nmi)) {
				uv_set_in_nmi(cpu, hub_nmi);
				nmi = 1;
				break;
			}

			/* MMR NMI flag is clear */
			raw_spin_unlock(&hub_nmi->nmi_lock);

		} else {
			/* wait a moment for the hub nmi locker to set flag */
			cpu_relax();
			udelay(uv_nmi_slave_delay);

			/* re-check hub in_nmi flag */
			nmi = atomic_read(&hub_nmi->in_nmi);
			if (nmi)
				break;
		}

		/* check if this BMC missed setting the MMR NMI flag */
		if (!nmi) {
			nmi = atomic_read(&uv_in_nmi);
			if (nmi)
				uv_set_in_nmi(cpu, hub_nmi);
		}

	} while (0);

	if (!nmi)
		local64_inc(&uv_nmi_misses);

	return nmi;
}
Ejemplo n.º 3
0
/*
 * Adjust the priority chain. Also used for deadlock detection.
 * Decreases task's usage by one - may thus free the task.
 * Returns 0 or -EDEADLK.
 */
static int rt_mutex_adjust_prio_chain(struct task_struct *task,
				      int deadlock_detect,
				      struct rt_mutex *orig_lock,
				      struct rt_mutex_waiter *orig_waiter,
				      struct task_struct *top_task)
{
	struct rt_mutex *lock;
	struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter;
	int detect_deadlock, ret = 0, depth = 0;
	unsigned long flags;

	detect_deadlock = debug_rt_mutex_detect_deadlock(orig_waiter,
							 deadlock_detect);

	/*
	 * The (de)boosting is a step by step approach with a lot of
	 * pitfalls. We want this to be preemptible and we want hold a
	 * maximum of two locks per step. So we have to check
	 * carefully whether things change under us.
	 */
 again:
	if (++depth > max_lock_depth) {
		static int prev_max;

		/*
		 * Print this only once. If the admin changes the limit,
		 * print a new message when reaching the limit again.
		 */
		if (prev_max != max_lock_depth) {
			prev_max = max_lock_depth;
			printk(KERN_WARNING "Maximum lock depth %d reached "
			       "task: %s (%d)\n", max_lock_depth,
			       top_task->comm, task_pid_nr(top_task));
		}
		put_task_struct(task);

		return deadlock_detect ? -EDEADLK : 0;
	}
 retry:
	/*
	 * Task can not go away as we did a get_task() before !
	 */
	raw_spin_lock_irqsave(&task->pi_lock, flags);

	waiter = task->pi_blocked_on;
	/*
	 * Check whether the end of the boosting chain has been
	 * reached or the state of the chain has changed while we
	 * dropped the locks.
	 */
	if (!waiter)
		goto out_unlock_pi;

	/*
	 * Check the orig_waiter state. After we dropped the locks,
	 * the previous owner of the lock might have released the lock.
	 */
	if (orig_waiter && !rt_mutex_owner(orig_lock))
		goto out_unlock_pi;

	/*
	 * Drop out, when the task has no waiters. Note,
	 * top_waiter can be NULL, when we are in the deboosting
	 * mode!
	 */
	if (top_waiter && (!task_has_pi_waiters(task) ||
			   top_waiter != task_top_pi_waiter(task)))
		goto out_unlock_pi;

	/*
	 * When deadlock detection is off then we check, if further
	 * priority adjustment is necessary.
	 */
	if (!detect_deadlock && waiter->list_entry.prio == task->prio)
		goto out_unlock_pi;

	lock = waiter->lock;
	if (!raw_spin_trylock(&lock->wait_lock)) {
		raw_spin_unlock_irqrestore(&task->pi_lock, flags);
		cpu_relax();
		goto retry;
	}

	/* Deadlock detection */
	if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
		debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
		raw_spin_unlock(&lock->wait_lock);
		ret = deadlock_detect ? -EDEADLK : 0;
		goto out_unlock_pi;
	}

	top_waiter = rt_mutex_top_waiter(lock);

	/* Requeue the waiter */
	plist_del(&waiter->list_entry, &lock->wait_list);
	waiter->list_entry.prio = task->prio;
	plist_add(&waiter->list_entry, &lock->wait_list);

	/* Release the task */
	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
	if (!rt_mutex_owner(lock)) {
		/*
		 * If the requeue above changed the top waiter, then we need
		 * to wake the new top waiter up to try to get the lock.
		 */

		if (top_waiter != rt_mutex_top_waiter(lock))
			wake_up_process(rt_mutex_top_waiter(lock)->task);
		raw_spin_unlock(&lock->wait_lock);
		goto out_put_task;
	}
	put_task_struct(task);

	/* Grab the next task */
	task = rt_mutex_owner(lock);
	get_task_struct(task);
	raw_spin_lock_irqsave(&task->pi_lock, flags);

	if (waiter == rt_mutex_top_waiter(lock)) {
		/* Boost the owner */
		plist_del(&top_waiter->pi_list_entry, &task->pi_waiters);
		waiter->pi_list_entry.prio = waiter->list_entry.prio;
		plist_add(&waiter->pi_list_entry, &task->pi_waiters);
		__rt_mutex_adjust_prio(task);

	} else if (top_waiter == waiter) {
		/* Deboost the owner */
		plist_del(&waiter->pi_list_entry, &task->pi_waiters);
		waiter = rt_mutex_top_waiter(lock);
		waiter->pi_list_entry.prio = waiter->list_entry.prio;
		plist_add(&waiter->pi_list_entry, &task->pi_waiters);
		__rt_mutex_adjust_prio(task);
	}

	raw_spin_unlock_irqrestore(&task->pi_lock, flags);

	top_waiter = rt_mutex_top_waiter(lock);
	raw_spin_unlock(&lock->wait_lock);

	if (!detect_deadlock && waiter != top_waiter)
		goto out_put_task;

	goto again;

 out_unlock_pi:
	raw_spin_unlock_irqrestore(&task->pi_lock, flags);
 out_put_task:
	put_task_struct(task);

	return ret;
}
Ejemplo n.º 4
0
static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
		int exception_state)
{
	unsigned long flags;
	int sstep_tries = 100;
	int error;
	int cpu;
	int trace_on = 0;
	int online_cpus = num_online_cpus();

	#ifdef CONFIG_KGDB_KDB
	if (force_panic)	/* Force panic in previous KDB, so skip this time */
		return NOTIFY_DONE;
	#endif

	kgdb_info[ks->cpu].enter_kgdb++;
	kgdb_info[ks->cpu].exception_state |= exception_state;

	if (exception_state == DCPU_WANT_MASTER)
		atomic_inc(&masters_in_kgdb);
	else
		atomic_inc(&slaves_in_kgdb);

	if (arch_kgdb_ops.disable_hw_break)
		arch_kgdb_ops.disable_hw_break(regs);

acquirelock:
	/*
	 * Interrupts will be restored by the 'trap return' code, except when
	 * single stepping.
	 */
	local_irq_save(flags);

	cpu = ks->cpu;
	kgdb_info[cpu].debuggerinfo = regs;
	kgdb_info[cpu].task = current;
	kgdb_info[cpu].ret_state = 0;
	kgdb_info[cpu].irq_depth = hardirq_count() >> HARDIRQ_SHIFT;

	/* Make sure the above info reaches the primary CPU */
	smp_mb();

	if (exception_level == 1) {
		if (raw_spin_trylock(&dbg_master_lock))
			atomic_xchg(&kgdb_active, cpu);
		goto cpu_master_loop;
	}

	/*
	 * CPU will loop if it is a slave or request to become a kgdb
	 * master cpu and acquire the kgdb_active lock:
	 */
	while (1) {
cpu_loop:
		if (kgdb_info[cpu].exception_state & DCPU_NEXT_MASTER) {
			kgdb_info[cpu].exception_state &= ~DCPU_NEXT_MASTER;
			goto cpu_master_loop;
		} else if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) {
			if (raw_spin_trylock(&dbg_master_lock)) {
				atomic_xchg(&kgdb_active, cpu);
				break;
			}
		} else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
			if (!raw_spin_is_locked(&dbg_slave_lock))
				goto return_normal;
		} else {
return_normal:
			/* Return to normal operation by executing any
			 * hw breakpoint fixup.
			 */
			if (arch_kgdb_ops.correct_hw_break)
				arch_kgdb_ops.correct_hw_break();
			if (trace_on)
				tracing_on();
			kgdb_info[cpu].exception_state &=
				~(DCPU_WANT_MASTER | DCPU_IS_SLAVE);
			kgdb_info[cpu].enter_kgdb--;
			smp_mb__before_atomic_dec();
			atomic_dec(&slaves_in_kgdb);
			dbg_touch_watchdogs();
			local_irq_restore(flags);
			return 0;
		}
		cpu_relax();
	}

	/*
	 * For single stepping, try to only enter on the processor
	 * that was single stepping.  To guard against a deadlock, the
	 * kernel will only try for the value of sstep_tries before
	 * giving up and continuing on.
	 */
	if (atomic_read(&kgdb_cpu_doing_single_step) != -1 &&
	    (kgdb_info[cpu].task &&
	     kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) {
		atomic_set(&kgdb_active, -1);
		raw_spin_unlock(&dbg_master_lock);
		dbg_touch_watchdogs();
		local_irq_restore(flags);

		goto acquirelock;
	}

	if (!kgdb_io_ready(1)) {
		kgdb_info[cpu].ret_state = 1;
		goto kgdb_restore; /* No I/O connection, resume the system */
	}

	/*
	 * Don't enter if we have hit a removed breakpoint.
	 */
	if (kgdb_skipexception(ks->ex_vector, ks->linux_regs))
		goto kgdb_restore;

	/* Call the I/O driver's pre_exception routine */
	if (dbg_io_ops->pre_exception)
		dbg_io_ops->pre_exception();

	/*
	 * Get the passive CPU lock which will hold all the non-primary
	 * CPU in a spin state while the debugger is active
	 */
	if (!kgdb_single_step)
		raw_spin_lock(&dbg_slave_lock);

#ifdef CONFIG_SMP
	/* Signal the other CPUs to enter kgdb_wait() */
	if ((!kgdb_single_step) && kgdb_do_roundup)
		kgdb_roundup_cpus(flags);
#endif

	/*
	 * Wait for the other CPUs to be notified and be waiting for us:
	 */
	while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) +
				atomic_read(&slaves_in_kgdb)) != online_cpus)
		cpu_relax();

	/*
	 * At this point the primary processor is completely
	 * in the debugger and all secondary CPUs are quiescent
	 */
	dbg_deactivate_sw_breakpoints();
	kgdb_single_step = 0;
	kgdb_contthread = current;
	exception_level = 0;
	trace_on = tracing_is_on();
	if (trace_on)
		tracing_off();

	while (1) {
cpu_master_loop:
		if (dbg_kdb_mode) {
			kgdb_connected = 1;
			error = kdb_stub(ks);
			if (error == -1)
				continue;
			kgdb_connected = 0;
		} else {
			error = gdb_serial_stub(ks);
		}

		if (error == DBG_PASS_EVENT) {
			dbg_kdb_mode = !dbg_kdb_mode;
		} else if (error == DBG_SWITCH_CPU_EVENT) {
			kgdb_info[dbg_switch_cpu].exception_state |=
				DCPU_NEXT_MASTER;
			goto cpu_loop;
		} else {
			kgdb_info[cpu].ret_state = error;
			break;
		}
	}

	/* Call the I/O driver's post_exception routine */
	if (dbg_io_ops->post_exception)
		dbg_io_ops->post_exception();

	if (!kgdb_single_step) {
		raw_spin_unlock(&dbg_slave_lock);
		/* Wait till all the CPUs have quit from the debugger. */
		while (kgdb_do_roundup && atomic_read(&slaves_in_kgdb))
			cpu_relax();
	}

kgdb_restore:
	if (atomic_read(&kgdb_cpu_doing_single_step) != -1) {
		int sstep_cpu = atomic_read(&kgdb_cpu_doing_single_step);
		if (kgdb_info[sstep_cpu].task)
			kgdb_sstep_pid = kgdb_info[sstep_cpu].task->pid;
		else
			kgdb_sstep_pid = 0;
	}
	if (arch_kgdb_ops.correct_hw_break)
		arch_kgdb_ops.correct_hw_break();
	if (trace_on)
		tracing_on();

	kgdb_info[cpu].exception_state &=
		~(DCPU_WANT_MASTER | DCPU_IS_SLAVE);
	kgdb_info[cpu].enter_kgdb--;
	smp_mb__before_atomic_dec();
	atomic_dec(&masters_in_kgdb);
	/* Free kgdb_active */
	atomic_set(&kgdb_active, -1);
	raw_spin_unlock(&dbg_master_lock);
	dbg_touch_watchdogs();
	local_irq_restore(flags);

	#ifdef CONFIG_KGDB_KDB
	/* If no user input, force trigger kernel panic here */
	if (force_panic) {
		printk("KDB : Force Kernal Panic ! \n");
		do { *(volatile int *)0 = 0; } while (1);
	}
	#endif
		
	return kgdb_info[cpu].ret_state;
}