Wine kernel acceleration module?

Gavriel State gav at
Thu Jan 23 00:58:22 CST 2003

Francois Gouget wrote:
> But of course that's true only if the kernel module has a bug.
> With the shared memory server any Windows application can crash all the
> others (but not the machine).
> To sum up, here's a table of what crashes based on the source of the
> bug:
>                   | Current       | Kernel         | Shm
> ------------------+---------------+----------------+--------------------
> Bug in the server | Wine          | Machine        | Wine
> ------------------+---------------+----------------+--------------------
> Bug in a Windows  | Process       | Process        | Wine
> application       |               |                |
> So you're better of with the kernel module if the bug is in the
> application, and you're better of with shm if the bug is in the server.
> Then it's a matter of which one is more likely. It's also a good
> argument for having the option to keep using the current server so that
> you can make the trade-off between speed and stability yourself.

The ShmServer is designed with that in mind.  The server code has
been moved into a shared library, and the wineserver process still
exists in the ShmServer model.  While it's not actually available in the
current code, it would be trivial to restrict access to the shm area
to specific trusted processes and force other processes to go through
the normal wineserver route.

Additionally, the ShmServer is designed so that the actual shared
memory area can be write-locked until a server call is made.  Thus it
becomes very difficult, though not completely impossible, for an
individual process to scribble over the server memory by accident.
So the bottom right entry in your table should perhaps be changed
to read '99% Process / 1% Wine'

What it does *not* prevent is a deliberately malicious app scribbling
over server memory - certainly a problem, but for many uses of Wine,
not a significant one.

Another key factor in favour of the ShmServer is that we've got
a working prototype available right now that runs several real-world
apps. 8-)

Take care,

Gavriel State, CEO & CTO
TransGaming Technologies Inc.
gav at

Let the games begin

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