Suggestions on process integrity checking

[Jose Luis Marchetti <joseluismarchetti@yahoo.com.br>]

Hi,

I need to implement a process integrity check, this is to make sure that a process that is running at the time of checking was not corrupted since it was first loaded in memory.
I would appreciate suggestions on where I should implement this in the Linux kernel, my first outline of this work is:

1) Add a field to task_struct that would hold some sort of process digital signature, it could be a CRC32 of process code space, this is not defined yet.
2) For simplicity let us assume an elf file is being executed, in binfmt_elf.c I see the elf file program segments are mmap to the virtual addresses and no read is actually done there ( or am I wrong ?). Where the reading of program segments is actually being done.
3) When the program segments are read in memory I need to update the process digital signature.
4) Then there is the checking part, if the kernel have to perform this checking periodically, how/where do you suggest it to be implemented ?

I was not successful in finding any similar implementation on the Internet that I could base my work on, if you know of any, please let me know.

Thanks in advance for any suggestion.

José Luís Marchetti