Norman Feske 20d8655a7f Linux: move process creation into core ... Genode used to create new processes by directly forking from the respective Genode parent using the process library. The forking process created a PD session at core merely for propagating the PID of the new process into core (for later destruction). This traditional mechanisms has the following disadvantages: First, the PID reported by the creating process to core cannot easily be validated by core. Therefore core has to trust the PD client to not specify a PID of an existing process, which would happen to be killed once the PD session gets destructed. This problem is documented by issue #318. Second, there is no way for a Genode process to detect the failure of its any grandchildren. The immediate parent of a faulting process could use the SIGCHLD-and-waitpid mechanism to observe its children but this mechanism does not work transitively. By performing the process creation exclusively within core, all Genode processes become immediate child processes of core. Hence, core can respond to failures of any of those processes and reflect such conditions via core's session interfaces. Furthermore, the PID associated to a PD session is locally known within core and cannot be forged anymore. In fact, there is actually no need at all to make processes aware of any PIDs of other processes. Please note that this patch breaks the 'chroot' mechanism that comes in the form of the 'os/src/app/chroot' program. Because all processes are forked from core, a chroot'ed process could sneak outside its chroot environment by just creating a new Genode process. To address this issue, the chroot mechanism must be added to core.		2012-11-05 17:31:04 +01:00
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client.h	Linux: move process creation into core	2012-11-05 17:31:04 +01:00
linux_pd_session.h	Linux: move process creation into core	2012-11-05 17:31:04 +01:00