创建设备驱动程序，但是当调用函数ioctl时，它说"ioctl(*，0x *" [英] Create a device driver, but when call the function ioctl , it say "ioctl(*, 0x* "

问题描述

大家好，

谢谢你的帮助.

我尝试构建设备驱动程序并成功构建它.

当我调用ioctl系统调用时，它提示杀死".

然后我用strace命令运行，它说" ioctl(3，0x22< unfinished ... ="> +++被SIGKILL杀死+++被杀死". >
相关的驱动程序代码为:

Hi All,

Thank you for help.

I try to build a device driver and have build it Successfully.

When I call the ioctl system call, it prompts "Killed".

Then I run with strace command, it say "ioctl(3, 0x22 <unfinished ...=""> +++ killed by SIGKILL +++ Killed".

The related driver code is:

#define TEST_IOC_MAGIC 0x00
//Documentation/ioctl-number.txt say 0x00~0x1F are been used.
#define TEST_IOCRESET _IO(TEST_IOC_MAGIC, 0x22)
....
static const struct file_operations globalfifo_fops =
{
       .unlocked_ioctl = globalfifo_ioctl,

};
...
static int globalfifo_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long arg)
{
      ...
      case TEST_IOCRESET:
      ....
}

相关程序代码为:

The related program code is:

int main()
{
      //  /dev/globalfifopoll is the device file.
      fd = open("/dev/globalfifopoll", O_CREAT|O_RDWR|O_NONBLOCK);
      ioctl(fd, TEST_IOCRESET, 0);
}

设备驱动程序和程序均已成功构建.同时，当您向其写入缓冲区数据或从中读取缓冲区数据时，设备驱动程序可以正常工作.

我不知道哪里出了问题.在程序中，函数open()将值3返回给fd.但是在运行代码ioctl()时，它会显示" ioctl(3，0x22< unfinished ... ="> ".

如果删除代码ioctl(fd, TEST_IOCRESET, 0)，该程序可以正常运行.

谢谢您的帮助.

The device driver and the program are both build Successfully. Meanwhile, the device driver can work well when you write buffer data to it or read buffer data from it.

I don''t know where is wrong. In the program, the function open() return value 3 to fd. But when run the code ioctl(), it says "ioctl(3, 0x22 <unfinished ...=""> ".

If I delete the code ioctl(fd, TEST_IOCRESET, 0), the program can run well.

Thank you for your help.

推荐答案

对不起，错误的结果说是ioctl(3，0x22(未完成....).

我在globalfifo_ioctl()函数中编写了日志，但是日志不是print(使用dmesg命令查看).我确定这个设备驱动程序可以正常工作，因为我可以在驱动程序的其他界面中打印其他日志.

Sorry, the wrong result say ioctl(3, 0x22 (unfinished ....).

I write the log in the function of globalfifo_ioctl(), but the log is not print( use the command dmesg to see). I''m sure this device driver can work well, because I can print other log in other interfaces of the driver.

哦，我解决了.谢谢您的通知.

原因是:

在Linux版本2.6.32之前，ioctl驱动程序方法是:
静态int(* ioctl)(struct inode * inode，结构文件* filp，unsigned int cmd，unsigned long arg);
我的linux版本是2.6.38，ioctl驱动程序方法是:
静态长整数(* ioctl)(结构文件* filp，unsigned int cmd，unsigned long arg)

在我的设备驱动程序中，我使用了第一个ioctl驱动程序方法.当我使用第二个ioctl驱动程序方法时，一切正常.

Oh, I resolve it. Thank you for your notice.

The reason is that:

Before the linux version 2.6.32, the ioctl driver method is :
static int (*ioctl)(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long arg);
My linux version is 2.6.38, the ioctl driver method is :
static long (*ioctl)(struct file *filp, unsigned int cmd, unsigned long arg)

In my device driver, I use the first ioctl driver method, that is abandon. When I use the second ioctl driver method, everything is OK.

这篇关于创建设备驱动程序，但是当调用函数ioctl时，它说"ioctl(*，0x *"的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！