This patch eliminates the "no attachment at..." warnings, which
were caused by a use-after-free problem of dataspaces. When a
dataspace was destroyed, the users of the dataspace were not
informed and therefore could not revert possible attachments to
RM sessions. The fix introduces a callback mechanism that allows
dataspace users (i.e., RM regions) to register for the event that
a dataspace vanishes.
The following types of dataspaces are handled:
* RAM dataspaces
* ROM dataspaces
* The process binary
* The binary of the dynamic linker
* Args dataspace
* Sysio dataspace
* Env dataspace
* managed RM dataspaces
The handling of ROM dataspaces is still not complete. When forking,
the ROM dataspace of the parent process gets just reused without
creating proper meta data ('Dataspace_info') for the forked process.
Similar issues might arise from other special dataspaces (e.g.,
args, env, sysio).
This patch removes all "no attachment at..." warnings except for
one (an attachment at 0).
Issue #485
With this patch the destruction of Noux 'Child' objects gets delayed
further until the exit signal has been dispatched. This prevents the
self-destruction of the signal dispatcher, which is a member of the
'Child' object.
Fixes#603.
With this patch, when a child exits, all of its open file descriptors get
closed immediately. This is necessary to unblock the parent if it is
trying to read from a pipe (connected to the child) before calling
'wait4()'.
Fixes#357.
Alexander Boettcher
Norman Feske
Christian Prochaska