【已解决】erx任务出现PC指针为0的hard fault

发布于 2024-10-23 15:58:14 浏览：264 订阅该版

硬件：GD32和STM32都有同样问题
系统：RT-Thread V3.0
协议栈：lwip 1.4.1
问题现象：接入以太网络后，随机出现hard fault错误，不接入以太网没有问题，并且网络流量加大后概率变大
出现频率：1天~3个月随机出现
寄存器：

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20241023/982cb1f4e4464c7e50cb6435c3a0dd41.png.webp)

代码：

```c
rt_err_t rt_mb_recv(rt_mailbox_t mb, rt_uint32_t *value, rt_int32_t timeout)
{
    struct rt_thread *thread;
    register rt_ubase_t temp;
    rt_uint32_t tick_delta;

/* parameter check */
    RT_ASSERT(mb != RT_NULL);

/* initialize delta tick */
    tick_delta = 0;
    /* get current thread */
    thread = rt_thread_self();

RT_OBJECT_HOOK_CALL(rt_object_trytake_hook, (&(mb->parent.parent)));

/* disable interrupt */
    temp = rt_hw_interrupt_disable();

/* for non-blocking call */
    if (mb->entry == 0 && timeout == 0)
    {
        rt_hw_interrupt_enable(temp);

return -RT_ETIMEOUT;
    }

/* mailbox is empty */
    while (mb->entry == 0)
    {
        /* reset error number in thread */
        thread->error = RT_EOK;

/* no waiting, return timeout */
        if (timeout == 0)
        {
            /* enable interrupt */
            rt_hw_interrupt_enable(temp);

thread->error = -RT_ETIMEOUT;

return -RT_ETIMEOUT;
        }

RT_DEBUG_IN_THREAD_CONTEXT;
        /* suspend current thread */
        rt_ipc_list_suspend(&(mb->parent.suspend_thread),
                            thread,
                            mb->parent.parent.flag);

/* has waiting time, start thread timer */
        if (timeout > 0)
        {
            /* get the start tick of timer */
            tick_delta = rt_tick_get();

RT_DEBUG_LOG(RT_DEBUG_IPC, ("mb_recv: start timer of thread:%s\n",
                                        thread->name));

/* reset the timeout of thread timer and start it */
            rt_timer_control(&(thread->thread_timer),
                             RT_TIMER_CTRL_SET_TIME,
                             &timeout);
            rt_timer_start(&(thread->thread_timer));
        }

/* enable interrupt */
        rt_hw_interrupt_enable(temp);

/* re-schedule */
        rt_schedule();

/* resume from suspend state */
        if (thread->error != RT_EOK)
        {
            /* return error */
            return thread->error;
        }

/* disable interrupt */
        temp = rt_hw_interrupt_disable();

/* if it's not waiting forever and then re-calculate timeout tick */
        if (timeout > 0)
        {
            tick_delta = rt_tick_get() - tick_delta;
            timeout -= tick_delta;
            if (timeout < 0)
                timeout = 0;
        }
    }

/* fill ptr */
    *value = mb->msg_pool[mb->out_offset];

/* increase output offset */
    ++ mb->out_offset;
    if (mb->out_offset >= mb->size)
        mb->out_offset = 0;
    /* decrease message entry */
    mb->entry --;

/* resume suspended thread */
    if (!rt_list_isempty(&(mb->suspend_sender_thread)))
    {
        rt_ipc_list_resume(&(mb->suspend_sender_thread));

/* enable interrupt */
        rt_hw_interrupt_enable(temp);

RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mb->parent.parent)));

rt_schedule();

return RT_EOK;
    }

/* enable interrupt */
    rt_hw_interrupt_enable(temp);

/* LR指针： 0x0804fd9b 所在位置 */
    RT_OBJECT_HOOK_CALL(rt_object_take_hook, (&(mb->parent.parent)));

return RT_EOK;
}
```