- KIP's pointer to UTCB seems to work with existing l4lib ipc functions.
- Works up to clone()
- In clone we mmap() the same UTCB on each new thread - excessive.
- Generally during page fault handling, cloned threads may fault on the same page
multiple times even though a single handling would be enough for all of them.
Need to detect and handle this.
Added setting of utcb address to l4_thread_control.
This is going to be moved to exchange_registers() since we need to pass
both the utcb physical and virtual address and exregs fits such context
modification better than thread_control.
Previously a so-called utcb shared page was used for transfering
data between posix services. This was a special shmat/get/dt case
allocating from its own virtual pool. Now the term utcb is renamed
as a shared page and integrated with the shm* handling routines.
Generic l4 threads will use long-ipc and not this method. Posix
services will continue to communicate on a shared page for now.
modified: tasks/libl4/include/l4lib/ipcdefs.h
modified: tasks/libl4/src/init.c
new file: tasks/libposix/init.c
modified: tasks/mm0/include/shm.h
modified: tasks/mm0/include/task.h
deleted: tasks/mm0/include/utcb.h
modified: tasks/mm0/main.c
modified: tasks/mm0/src/boot.c
modified: tasks/mm0/src/clone.c
modified: tasks/mm0/src/execve.c
modified: tasks/mm0/src/exit.c
modified: tasks/mm0/src/init.c
modified: tasks/mm0/src/shm.c
modified: tasks/mm0/src/task.c
deleted: tasks/mm0/src/utcb.c
deleted: tools/l4-qemu
It turned out we used one version of kmalloc for malloc() and another for kfree()!
Now fixed.
Added parent-child relationship to tasks. Need to polish handling CLONE_PARENT and THREAD.
- Fixed an important bug with shadow object handling.
When a shadow is dropped, if there are references left
to it, both the object in front and dropped object becomes
a shadow of the original object underneath. We had thought
of this case but had not increase the shadow count.
- Added a test mechanism that tests the number of objects,
vmfiles, shadows etc. by first counting them and trying to
reach the same number by other means, i.e. per-object-shadow counts.
It discovered a plethora of bugs.
- Added new set of functions to register objects, files and tasks
globally with the pager, these functions introduce a refcount as
well as adding structures to linked lists.
- fork/exit now seems to work stably i.e. no negative shadow counts etc.
- Added cleaner allocation of shm addresses by moving the allocation to do_mmap().
- Added deletion routine for all objects: shadow, vm_file of type vfs_file, shm_file, etc.
- Need to make sure objects get deleted properly after exit().
- Currently we allow a single, unique virtual address for each shm segment.
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.
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.
Environment is backed by a special per-task file maintained by mm0 for each task.
This file is filled in by the env pager, by simple copying of env data into the
faulty page upon a fault. UTCB and all anon regions (stack) could use the same
scheme.
Fixed IS_ERR(x) to accept negative values that are above -1000 for errors. This
protects against false positives for pointers such as 0xE0000000.
modified: include/l4/generic/scheduler.h
modified: include/l4/macros.h
modified: src/arch/arm/exception.c
modified: tasks/fs0/include/linker.lds
modified: tasks/libl4/src/init.c
modified: tasks/libposix/shm.c
new file: tasks/mm0/include/env.h
modified: tasks/mm0/include/file.h
new file: tasks/mm0/include/lib/addr.h
deleted: tasks/mm0/include/lib/vaddr.h
modified: tasks/mm0/include/task.h
new file: tasks/mm0/include/utcb.h
new file: tasks/mm0/src/env.c
modified: tasks/mm0/src/fault.c
modified: tasks/mm0/src/file.c
modified: tasks/mm0/src/init.c
new file: tasks/mm0/src/lib/addr.c
modified: tasks/mm0/src/lib/idpool.c
deleted: tasks/mm0/src/lib/vaddr.c
modified: tasks/mm0/src/mmap.c
modified: tasks/mm0/src/shm.c
modified: tasks/mm0/src/task.c
new file: tasks/mm0/src/utcb.c
modified: tasks/test0/include/linker.lds
This will help when syscalls have long arguments individual
utcbs can be mapped to server tasks and kept mapped in until the
tasks die, as opposed to map requests every time a server task maps
a different utcb at the same virtual address.
The changes have preparation code to also passing the utcb info
through the stack as part of the environment.
To sum up env and arg regions have also been added above the stack and
env region is to be used to pass on the utcb address information at
task startup.
This implements the infrastructure for read/write system calls where
file content is first searched in mm0's page cache and then read-in
or written via the vfs read/write functions.
modified: tasks/fs0/src/syscalls.c
modified: tasks/mm0/include/lib/bit.h
modified: tasks/mm0/include/lib/idpool.h
modified: tasks/mm0/include/task.h
modified: tasks/mm0/include/vm_area.h
modified: tasks/mm0/main.c
modified: tasks/mm0/src/devzero.c
modified: tasks/mm0/src/fault.c
new file: tasks/mm0/src/file.c
modified: tasks/mm0/src/init.c
modified: tasks/mm0/src/lib/bit.c
modified: tasks/mm0/src/lib/idpool.c
modified: tasks/mm0/src/task.c
Boot files and tasks are now initialised together. Theads can ask for particular
space and thread ids, if they're unused. This enables us to get predefined ids for
known tasks such as the VFS task.
Fixes to README
Other minor fixes.
Changed l4id_t type to integer to recognise negative id values like L4_ANYTHREAD.
Added an extremely simple script that cleans and builds everything in right order.
Increased boot pmds by one:
This is due to the fact that if the 1MB initial allocation area of the kernel is
not 1MB-aligned, it is ought to be mapped from the middle of one MB to next,
which requires 2 pmds.
modified: .gdbinit
modified: README
new file: buildall.sh
modified: include/l4/arch/arm/types.h
modified: include/l4/generic/scheduler.h
modified: loader/kernel.S
modified: loader/main.c
modified: loader/mylink.lds
modified: loader/start.axf.S
modified: src/glue/arm/init.c
modified: src/glue/arm/memory.c
modified: tasks/fs0/src/bdev.c
modified: tasks/mm0/include/kdata.h
modified: tasks/mm0/include/vm_area.h
modified: tasks/mm0/src/init.c
modified: tasks/mm0/src/task.c
modified: tools/ksym_to_lds.py
modified: tools/l4-qemu
