- Only the topmost parent prints pass messages. Any failed child can print fail message.
- Added testing of 16 forked threads doing file create/read/write/close and
16 forked x 4 cloned = 64 threads spawning/exiting
- Updated sleeping paths such that a task is atomically put into
a runqueue and made RUNNABLE, or removed from a runqueue and made SLEEPING.
- Modified vma dropping sources to handle both copy_on_write() and exit() cases
in a common function.
- Added the first infrastructure to have a pager to suspend a task and wait for
suspend completion from the scheduler.
fs0 used to receive open() requests and notify pager about them via a syscall ipc.
This caused deadlocks because normally request flow is mm0 -> fs0 on all other calls.
The solution was to have mm0 ask and validate file descriptors from fs0 on the first
request instance that involved that file descriptor. By this method we delay the
validation of the fd until its first use, and avoid deadlock. It also fits well with
the lazy request handling design philosophy.
Removed some commented out code.
Removed excessive printfs.
Fixed spid not initialising for mm0
Fixed some faults with fs0.
TODO:
- Need to store vfs files in a separate list.
- Need to define vnum as a vfs-file-specific data, i.e. in priv_data field of vm_file.
- Need to then fix vfs_receive_sys_open.
Headers 3 headers related to message registers and utcbs are now merged under
utcb.h in libl4. Some message register definitions used by the kernel are now
moved into kernel's glue/message.h. This avoids the duplication of same
definitions. Also the total number of mregs are now determined by arch-specific
kernel header, which is good.
Previously we had changed the method of setting the ipc tag from l4_ipc() call
argument to being passed as a message register.
- This change was not reflected in l4_ipc() signature as it still had a 3rd argument,
even though ignored.
- l4_set_sender and _set_tag had their arguments wrong way around.
- Previously 5 mrs were passed onto utcb instead of 6, relying on the fact that
l4_ipc tag argument was being passed in r3 directly, this wasnt true anymore
with new convention, but wasn't catered for.
TODO:
- MM0 shouldn't really allocate tids itself, but use ones supplied by C0.
- Sender tid shouldn't really passed by the sender task, but rather by C0. Otherwise
security can be easily breached by user tasks pretending to be other tasks. This
would also save us a message register.
Previously python hex() would put an extra 'L' after printing out the
value and this would be trimmed in readelf.py. Now it doesn't seem to
do that so the lsd of the number was trimmed. This patch fixes that.
