Re: Organization and symbol lookup for shared libraries

[Bryce McKinlay <mckinlay at redhat dot com>]

Andrew Haley wrote:

> James Damour writes:
> > Bryce McKinlay writes:
> >  > Perhaps this step (running gcj-dbtool) could be avoided altogether: if 
> >  > the cache is found to be out-of-date at runtime, because someone added 
> >  > or changed a shared library without re-running dbtool, then we'll need 
> >  > to open those modified shared libraries at runtime anyway. Since we have 
> >  > to open them, the runtime could simply update the cache file on-the-fly?
> > 
> > The problem with that is permissions.
>  
What should happen in this situation is for libgcj to fall back to 
loading the shared libraries without the cache, and print a warning that 
the cache file needs to be updated by running gcj-dbtool.

One thing we do need to consider carefully, though, is security - we 
don't want a suid root gcj application blindly opening shared libraries 
from user-writable directories!

> Also, there's a potential issue with shared access.  I'm not
> sure it's wothwhile.
>  
I don't see what the problem is with sharing. Surely, provided the cache 
file is updated atomically, it will never be seen in an inconsistent state?

Regards

Bryce