Fixes races where threads on another CPU are joining the
exiting thread, since it could still be running when
the joiners wake up on a different CPU.
Fixes problems where the thread object is still being
used by the kernel when the fn_abort() function is called,
preventing the thread object from being recycled or
freed back to a slab pool.
Fixes a race where a thread is aborted from one CPU while
it self-aborts on another CPU, that was currently worked
around with a busy-wait.
Precedent for doing this comes from FreeRTOS, which also
performs final thread cleanup in the idle thread.
Some logic in z_thread_single_abort() rearranged such that
when we release sched_spinlock, the thread object pointer
is never dereferenced by the kernel again; join waiters
or fn_abort() logic may free it immediately.
An assertion added to z_thread_single_abort() to ensure
it never gets called with thread == _current outside of an ISR.
Some logic has been added to ensure z_thread_single_abort()
tasks don't run more than once.
Fixes: #26486
Related to: #23063#23062
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
f5a7e1a108