kernel/spinlock: Augment runtime validation

There was an existing validation layer in the spinlock implementation,
but it was only enabled when both SMP and CONFIG_DEBUG were enabled,
which meant that nothing was using it.  Replace it with a more
elaborate framework that ensures that every lock taken is not already
taken by the current CPU and is released on the same CPU by the same
thread.

This catches the much more common goof of locking a spinlock
recursively, which would "work" on uniprocessor setups but have the
side effect of releasing the lock prematurely at the end of the inner
lock.  We've done that in two spots already.

Note that this patch causes k_spinlock_t to have non-zero size on
builds with CONFIG_ASSERT, so expect a little data and code size
increase.  Worth it IMHO.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
1 file changed