发现 "rt-thread\components\drivers\src\waitqueue.c" 中的一个bug

发布于 2018-08-16 13:02:24 浏览：2507 订阅该版

本帖最后由 lugang_2920213 于 2018-8-16 20:54 编辑

我在板子上面跑了一个TCP服务，一个UDP服务。（启用了SAL模块）
板子可以正常发送udp数据给调试工具，但是调试工具给板子UDP服务发送数据时，板子会进入硬件错误。
出错时lwip调试信息（调试工具发送的数据为"rtthread\r\n"）

```
udp_input: received datagram of length 18
UDP header:
+-------------------------------+
|      2150     |      2150     | (src port, dest port)
+-------------------------------+
|        18     |     0xa533    | (len, chksum)
+-------------------------------+
udp (192.168.0.100, 2150) <-- (192.168.0.101, 2150)
pcb (0.0.0.0, 2150) --- (0.0.0.0, 0)
pcb (0.0.0.0, 68) --- (0.0.0.0, 67)
pcb (0.0.0.0, 49153) --- (0.0.0.0, 0)
udp_input: calculating checksum

```

执行“rt-thread\components\drivers\src\waitqueue.c”文件中的65行（下面代码21行）时，出现硬件错误。

```
void rt_wqueue_wakeup(rt_wqueue_t *queue, void *key)
{
    rt_base_t level;
    register int need_schedule = 0;

rt_list_t *queue_list;
    struct rt_list_node *node;
    struct rt_wqueue_node *entry;

queue_list = &(queue->waiting_list);

level = rt_hw_interrupt_disable();
    /* set wakeup flag in the queue */
    queue->flag = RT_WQ_FLAG_WAKEUP;

if (!(rt_list_isempty(queue_list)))
    {
        for (node = queue_list->next; node != queue_list; node = node->next)
        {
            entry = rt_list_entry(node, struct rt_wqueue_node, list);
            if (entry->wakeup(entry, key) == 0)
            {
                rt_thread_resume(entry->polling_thread);
                need_schedule = 1;

rt_wqueue_remove(entry);
                break;
            }
        }
    }
    rt_hw_interrupt_enable(level);

if (need_schedule)
        rt_schedule();
}
```

硬件错误前的状态为：

![](http://www.ihomeonline.net/status.png)

出错的原因是传入了一个空的链表。我没有研究过rtt的内核，不知道是否在其它地方有对参数有效性的判断。所以简单的在这里进行了判断，现在程序能正常运行。

我修改后的代码
我添加了（11-14行）

```
void rt_wqueue_wakeup(rt_wqueue_t *queue, void *key)
{
    rt_base_t level;
    register int need_schedule = 0;

rt_list_t *queue_list;
    struct rt_list_node *node;
    struct rt_wqueue_node *entry;

queue_list = &(queue->waiting_list);
   if ((queue_list->next == NULL) &&
        (queue_list->prev == NULL)) {
        return;
    }

level = rt_hw_interrupt_disable();
    /* set wakeup flag in the queue */
    queue->flag = RT_WQ_FLAG_WAKEUP;

if (!(rt_list_isempty(queue_list)))
    {
        for (node = queue_list->next; node != queue_list; node = node->next)
        {
            entry = rt_list_entry(node, struct rt_wqueue_node, list);
            if (entry->wakeup(entry, key) == 0)
            {
                rt_thread_resume(entry->polling_thread);
                need_schedule = 1;

rt_wqueue_remove(entry);
                break;
            }
        }
    }
    rt_hw_interrupt_enable(level);

if (need_schedule)
        rt_schedule();
}
```

我的运行环境：

1. 硬件信息

```
CPU: STM32F103VC
网卡: enc28j60

```

2. rtt版本

```
\ | /    - RT -     Thread Operating System
 / | \     3.1.0 build Aug 16 2018
 2006 - 2018 Copyright by rt-thread team
```

3. rtconfig.h

```
#ifndef RT_CONFIG_H__
#define RT_CONFIG_H__

/* Automatically generated file; DO NOT EDIT. */
/* RT-Thread Project Configuration */

#define SOC_STM32F1

/* RT-Thread Kernel */

#define RT_NAME_MAX 8
#define RT_ALIGN_SIZE 4
#define RT_THREAD_PRIORITY_32
#define RT_THREAD_PRIORITY_MAX 32
#define RT_TICK_PER_SECOND 100
#define RT_USING_OVERFLOW_CHECK
#define RT_USING_HOOK
#define RT_IDEL_HOOK_LIST_SIZE 4
#define IDLE_THREAD_STACK_SIZE 256
#define RT_DEBUG

/* Inter-Thread communication */

#define RT_USING_SEMAPHORE
#define RT_USING_MUTEX
#define RT_USING_EVENT
#define RT_USING_MAILBOX
#define RT_USING_MESSAGEQUEUE

/* Memory Management */

#define RT_USING_MEMPOOL
#define RT_USING_SMALL_MEM
#define RT_USING_HEAP

/* Kernel Device Object */

#define RT_USING_DEVICE
#define RT_USING_CONSOLE
#define RT_CONSOLEBUF_SIZE 128
#define RT_CONSOLE_DEVICE_NAME "uart1"
#define ARCH_ARM
#define ARCH_ARM_CORTEX_M
#define ARCH_ARM_CORTEX_M3

/* RT-Thread Components */

#define RT_USING_COMPONENTS_INIT

/* C++ features */

/* Command shell */

#define RT_USING_FINSH
#define FINSH_THREAD_NAME "tshell"
#define FINSH_USING_HISTORY
#define FINSH_HISTORY_LINES 5
#define FINSH_USING_SYMTAB
#define FINSH_USING_DESCRIPTION
#define FINSH_THREAD_PRIORITY 20
#define FINSH_THREAD_STACK_SIZE 2048
#define FINSH_CMD_SIZE 80
#define FINSH_USING_MSH
#define FINSH_USING_MSH_DEFAULT
#define FINSH_USING_MSH_ONLY
#define FINSH_ARG_MAX 6

/* Device virtual file system */

#define RT_USING_DFS
#define DFS_USING_WORKDIR
#define DFS_FILESYSTEMS_MAX 2
#define DFS_FILESYSTEM_TYPES_MAX 2
#define DFS_FD_MAX 32
#define RT_USING_DFS_ELMFAT

/* elm-chan's FatFs, Generic FAT Filesystem Module */

#define RT_DFS_ELM_CODE_PAGE 437
#define RT_DFS_ELM_WORD_ACCESS
#define RT_DFS_ELM_USE_LFN_0
#define RT_DFS_ELM_USE_LFN 0
#define RT_DFS_ELM_MAX_LFN 255
#define RT_DFS_ELM_DRIVES 2
#define RT_DFS_ELM_MAX_SECTOR_SIZE 4096
#define RT_DFS_ELM_USE_ERASE
#define RT_DFS_ELM_REENTRANT
#define RT_USING_DFS_DEVFS

/* Device Drivers */

#define RT_USING_DEVICE_IPC
#define RT_PIPE_BUFSZ 512
#define RT_USING_SERIAL

/* Using USB */

/* POSIX layer and C standard library */

#define RT_USING_LIBC
#define RT_USING_PTHREADS
#define RT_USING_POSIX

/* Network */

/* Socket abstraction layer */

#define RT_USING_SAL

/* protocol stack implement */

#define SAL_USING_LWIP
#define SAL_USING_POSIX
#define SAL_PROTO_FAMILIES_NUM 4

/* light weight TCP/IP stack */

#define RT_USING_LWIP
#define RT_USING_LWIP141
#define RT_LWIP_IGMP
#define RT_LWIP_ICMP
#define RT_LWIP_DNS
#define RT_LWIP_DHCP
#define IP_SOF_BROADCAST 1
#define IP_SOF_BROADCAST_RECV 1

/* Static IPv4 Address */

#define RT_LWIP_IPADDR "192.168.1.30"
#define RT_LWIP_GWADDR "192.168.1.1"
#define RT_LWIP_MSKADDR "255.255.255.0"
#define RT_LWIP_UDP
#define RT_LWIP_TCP
#define RT_MEMP_NUM_NETCONN 8
#define RT_LWIP_PBUF_NUM 16
#define RT_LWIP_RAW_PCB_NUM 4
#define RT_LWIP_UDP_PCB_NUM 6
#define RT_LWIP_TCP_PCB_NUM 4
#define RT_LWIP_TCP_SEG_NUM 40
#define RT_LWIP_TCP_SND_BUF 8196
#define RT_LWIP_TCP_WND 8196
#define RT_LWIP_TCPTHREAD_PRIORITY 10
#define RT_LWIP_TCPTHREAD_MBOX_SIZE 8
#define RT_LWIP_TCPTHREAD_STACKSIZE 1024
#define RT_LWIP_ETHTHREAD_PRIORITY 12
#define RT_LWIP_ETHTHREAD_STACKSIZE 1024
#define RT_LWIP_ETHTHREAD_MBOX_SIZE 8
#define LWIP_NETIF_STATUS_CALLBACK 1
#define SO_REUSE 1
#define LWIP_SO_RCVTIMEO 1
#define LWIP_SO_SNDTIMEO 1
#define LWIP_SO_RCVBUF 1
#define LWIP_NETIF_LOOPBACK 0
#define RT_LWIP_DEBUG
#define RT_LWIP_UDP_DEBUG
#define RT_LWIP_TCP_DEBUG

/* Modbus master and slave stack */

/* AT commands */

/* VBUS(Virtual Software BUS) */

/* Utilities */

/* ARM CMSIS */

#define RT_USING_RTT_CMSIS

/* Configure Uart */

#define RT_USING_UART1
#define RT_USING_UART2
#define RT_USING_UART3

/* STM32 Librarys Configuration */

#endif

```