Re: ARM kernel module supported reloc types

[Richard Earnshaw <richard.earnshaw%buzzard.freeserve.co.uk@localhost>]

On Fri, 2008-12-19 at 01:44 -0500, Rafal Boni wrote:
> On Thu, Dec 18, 2008 at 09:35:02PM -0800, Matt Thomas wrote:
> > Yes.  PC24 is not appropriate in dynamic shared library loading but  
> > since kernel modules are simple .o files, it is appropriate.
> 
> Ok, so the next hole I fall into is symbols being too far for the PC24
> reloc to resolve (printf in the example modules), and a crash related
> to the auto-loading of the compat module.
> 
> The second one I haven't dug into very much (it gave me a reason to give
> up for the night), but the first is interesting -- in the old LKM frame-
> work, the lkmtramp.awk scripts generated trampoline code for all targets
> of PC24 relocs... do we have an equivalent for the new modules?  Where is
> this supposed to happen in the new world order?
> 
> Thanks,
> --rafal
> 

It might be appropriate to compile kernel modules with -mlong-calls.
That way all the relocations to functions are turned into DATA relocs.
Doing that will simplify cache synchronization issues as well.

R.