Calling a system call in a kernel module

linuxdoniv · 08-08-2008, 03:03 AM

Hi,

an application can call a system call on a file, and based on the file type, proper implementation of the system call is chosen (using struct file_operations definition of a file ) and system call is executed.

Can a system call be called in a kernel module itself. Say a daemon running in kernel mode has to write something to the memory often, Then would not it be making system calls..?

Thanks....

linuxdoniv · 08-08-2008, 03:06 AM

also I think system calls are always made with file as one of the arguments...

are there any system calls made without specifying the file as argument. (as there is a need to switch to the kernel mode only when there is some hardware operation and all things are files in linux .. )

alex1983-0112 · 08-08-2008, 03:22 AM

int 0x80 ?

alex1983-0112 · 08-08-2008, 03:28 AM

Quote:

Originally Posted by linuxdoniv

are there any system calls made without specifying the file as argument.

Yes, but instead name of file in argument you must to point a file descriptor.