/ dev文件夹中的open（）设备

Question

I am writing a kernel module. I have a utility provided by the course staff, which is ran by web2py at the browser windows. The utility tries to access character devices at /dev folder, by calling open function (the utility is written in python)and gets "permission is denied" error.

I read that it is possible to run browser as a root but is depricated. Is there a way to set permissions for the devices thru the code?

Or I have to do it manualy each time

Answer 1

There are several ways to set permissions:

1) have a boot script (or the script that loads the module) set the permissions

2) write a udev rule that sets the owner/permissions when the device is created. The author of the kernel module can tell you how to setup the udev rules.

It's more secure to use chown to set the owner to your web user, than to use chmod and open the file up to anybody.