Re: Benchmarks (was Re: Hooking into Linux using the LTT)

From: Greg KH (gregat_private)
Date: Sat Apr 21 2001 - 09:57:38 PDT

  • Next message: jmjonesat_private: "Re: Benchmarks (was Re: Hooking into Linux using the LTT)"

    On Sat, Apr 21, 2001 at 01:38:43AM +0000, David Wagner wrote:
    > Greg KH  wrote:
    > >Not hard, consider the following code:
    > >	lock_kernel();
    > >	security_ops = &dummy_security_ops;
    > >	unlock_kernel();
    > 
    > That looks great as an *implementation*, but let me suggest that this
    > code be hidden behind a register_hook() / unregister_hook() interface.
    > In particular, I think it would be a good idea to ensure that policy
    > modules don't go modify the security_ops structure theirselves, but
    > go through some API -- this way the implementation of what's behind
    > the API can change to accomodate, e.g., locking or loading multiple
    > poilcy modules.
    > 
    > What do you think?  Do you agree?
    
    I agree about hiding the registration and unregistering behind a
    function call that handles it.  I did just that in the patch I posted.
    
    As for hiding access to the security_ops structure itself?  That's a
    much tricker thing to do.  Remember the LSM lives in kernel space along
    with the rest of the kernel, so it can touch any part of kernel memory
    that it wants to, even if we "hide" it.  Also any thing that implements
    this would cause the way to call the hooks to slow down.
    
    thanks,
    
    greg k-h
    
    _______________________________________________
    linux-security-module mailing list
    linux-security-moduleat_private
    http://mail.wirex.com/mailman/listinfo/linux-security-module
    



    This archive was generated by hypermail 2b30 : Sat Apr 21 2001 - 09:58:56 PDT