[Lguest] [PATCH 0/5] Boot protocol changes

[Rusty Russell]

On Thu, 2007-10-04 at 10:47 +0100, Chris Malley wrote:
> Hi guys
> 
> I gave these patches a try (on top of 2.6.23-rc9 plus the previously
> submitted 2.6.24 patch set).
> 
> The last two seem to cause Badness on my system, whereby if I start a
> guest (using the same bzImage as the host, as before) it seems to boot
> OK, and the host system still superficially looks stable (my X session
> is OK and I can interact with existing processes) but if I attempt to
> launch any new process on the host (even typing "ls" into a terminal
> window) I get a Segmentation fault.

I think this might actually be caused by a nasty bug in one of the
previous patches (patch 27).  I found it because every second time I
launched a guest it failed.  Strange, huh?

These lines in drivers/lguest/page_tables.c:

+               pte_t ro_gpte = gpte;
+               pte_wrprotect(ro_gpte);

Should be:

+               pte_t ro_gpte = pte_wrprotct(gpte);

That's the only "break the host" issue I know of...

Thanks!
Rusty.