- Fixed do_mmap() so that it returns mapped address, and various bugs.
- A child seems to fork with new setup, but with incorrect return value.
Need to use and test exregs() for fork + clone.
- Shmat searches an unmapped area if input arg is invalid, do_mmap()
should do this.
- Added mutex_trylock()
- Implemented most of exchange_registers()
- thread_control() now needs a lock for operations that can modify thread context.
- thread_start() does not initialise scheduler flags, now done in thread_create.
TODO:
- Fork/clone'ed threads should retain their context in tcb, not syscall stack.
- exchange_registers() calls in userspace need cleaning up.
sys_timer accumulates timer ticks into seconds, minutes, hours and days.
It's left to the user to calculate from days into a date. It is not yet
known if the calculation is even roughly correct.
Reduced 2 kmem_reclaim/grant calls into one kmem_control call.
Modified ipc handling so that from now on the kernel inspects and sets
the sender id if the receiver is receiving from L4_ANYTHREAD. This posed
a security problem since the receiver could not trust the sender for
sender information.
ipc_sendrecv() replaces ipc_sendwait() which was flawed. See ipc_sendrecv() for
how client/server communication works. Tested with page faults where the kernel
does an ipc_sendrecv() to faulty thread's pager and the pager successfully handles
the request, and returns back the result, which effectively restarts the faulty
thread.
