The sys_mem_pool implementation has a subtle error case where it
detected a simultaneous allocation after having released the lock, in
which case exactly one of the racing allocators will return with
-EAGAIN (the other one suceeds of course).
I documented this condition at the lower level, but forgot to actually
handle it at the k_mem_pool level where we want to retry once before
going to sleep, as it doesn't generally represent an empty heap. It
got caught by code auditing in:
https://github.com/zephyrproject-rtos/zephyr/issues/6757
(Full disclosure: I tested this by whiteboxing the first failure. I
wasn't able to put together a rig to reliably exercise the actual
race.)
This patch also fixes a noop thinko in the return logic in the same
function, which contained:
(ret == -EAGAIN) || (ret && ret != -ENOMEM)
The first term is needless and implied by the second.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
75398d2c38