[ELDK] function equivalent to the "system" in kernel space

[Ana Cláudia]

Hi,

I need to do this in my kernel module:
system("cd /ptin/install_dir/");
system("chmod 777 software_image.tar");
system("tar xzf software_image.tar");
system("cd /ptin/");
system("./swap");// swap is a shell script that I need to run

Somebody knows if exists a function equivalent to "system" (function to user space) for kernel space?
Thank you.

Cláudia