libffi prevents p11-kit from being usable with selinux

[Nikos Mavrogiannopoulos]

On Mon, 2015-09-21 at 15:12 +0200, Stef Walter wrote:

> Several functions (such as CloseAllSessions()) in PKCS#11 act
> globally.
> By returning a different closure for those function pointers to each
> caller, we can scope those effects. We don't do this only in the
> proxy
> module, but throughout the PKCS#11 API.
> 
> The following functions are routinely wrapped in a closure:
> 
> C_Initialize
> C_Finalize
> C_CloseAllSessions
> C_CloseSession
> C_OpenSession
> 
> In addition, if things like remoting or logging are enabled, then all
> functions are wrapped ... so their arguments can be remoted or logged
> respectively.
[...]
>  2. We could precompile NNNN closures into the executable, and these
>     would be consumed as necessary. This is how p11-kit used to 
> perform 
>     this task. It's really horrible code ... but could be done as a
> last
>     resort ... and the code is in the git history.

I've tried with avoiding the tmpdir in libffi, and have the same issue
with executable memory. So I think we are at this point...