Re: [Dazuko-devel] 2.1.0-pre4 posted

[John Ogness]

Sami Tikka wrote:
> Could you remind me (in case it has been discussed and I have forgotten) what 
> was the reason to base the Linux 2.6 version on LSM instead of system call 
> hooking? 
>
> I have done some experimenting and it seems I can hook system calls under 
> Linux 2.6 just the same way as it is done in Linux 2.4. The sys_call_table is 
> not exported but the code in dazuko_linux.c seems to be able to locate it.

Hi,

The reason is because the Linux kernel developers don't want people hooking 
the system call table. Using LSM is preferred. Using a stackable filesystem 
would be even better.

By using LSM, we are at least making an effort to "cooperate". One of our 
main goals is acceptance. We won't achieve this until we can get DazukoFS 
out the door. But until then, we are trying to be as "nice" as we can.

Would hooking the system call table under Linux 2.6 work? Yup, perfectly. 
But it isn't what we *should* do. If we start hooking the system call table, 
then we may once again run into the "cat 'n mouse" situation we had with 
RedHat and the Linux 2.4 kernel.

John Ogness

--
Dazuko Maintainer