Re: Why the linux does not allow the access to a file in the devicedriver?

["Daniel (Youngwhan) Song" <breadncup@xxxxxxxxx>]

Thank you, guys,

Now, I could understand of it and learned it.

Best Regards,
Daniel (Youngwhan) Song

On Thu, Jan 14, 2010 at 6:57 PM, snoppy1314 <snoppy1314@xxxxxxx> wrote:

Dear Daniel：

 

I think the most important reason is: the file your said is in the user-space, while the driver code is running in the kernel-space.For the security reason, the direct acess between these two space is forbidden.

The solution to your problem:

1. use the /proc or /sys filesystem

2. printk

3. write a user-space program to read these data from driver and then save them to a file

 

 

2010-01-15

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snoppy1314

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发件人： Daniel (Youngwhan) Song

发送时间： 2010-01-15  09:53:44

收件人： kernelnewbies

抄送：

主题： Why the linux does not allow the access to a file in the devicedriver?

Hi,

Could somebody help me to understand the reason why the linux kernel does not allow the access to a file in the device driver? For example, for debugging purpose, if a device driver want to log some data in a file by using open/write/read method like in user application, how a driver can access to a file in a specific filesystem? Any comment or docs or web pages would be appreciated.

Thank you,

Dan.