Re: Wine/Cedega and fedora 3

[Brian Gerst <bgerst didntduck org>]

Alan Cox wrote:

> On Mon, Dec 06, 2004 at 12:15:54PM +0100, Kjetil Nygård wrote:
>
> > 1. Removed prelinking 
> >   (Think it should have been enough to remove "exec-shield")
> > 2. echo 1>/proc/sys/vm/legacy_va_layout
>
>
> Or to put it another way "disabled security to make buggy application
> software work"
>
>
> > Is it possible to change these in fedora so that users doesn't have to
> > do this themselves?
>
>
> When put differently it sounds a bad idea to me. Perhaps Transgaming could
> lookg into why their software is making memory layout and exec assumptions
> (assuming they haven't already of course) ? If it is tripping a real bug it
> would be useful to know
>
> Alan

Wine (and derivatives) is sensitive to the VM layout because Windows 
binaries demand a specific virtual address range.  Many of these 
binaries are stripped and therefore non-relocatable.  The problem is 
that the new VM layout puts the libraries there, and Wine has no 
opportunity to tell the ELF loader that it needs that virtual address 
range free for its own use.  "setarch i386 -L wine ..." should work to 
disable exec-shield and legacy VM layout for just Wine, but the 
prelinked libraries will still load at the exec-shield address because 
there is no address range conflict at startup.  There needs to be a way 
to disable prelinked libraries for specific processes at execve time, so 
the libraries load at the "legacy" address range for that process.

Alternately, there needs to be a way for the ELF format to declare an 
address range as off-limits to the ELF loader.

--
				Brian Gerst