tree c4d5f50d4cc7f2685b9029a397942e260be7e7e4
parent 21b297bee9b1354b718c4701f6bebc4521742396
author Philipp Maier <pmaier@sysmocom.de> 1701688817 +0100
committer Philipp Maier <pmaier@sysmocom.de> 1704372931 +0100

ecu: fix alignment of fr_ecu_state

The member data[0] in struct osmo_ecu_state is used as an anchor to
attach private structs for a concrete ECU implementation. This works by
allocating more memory then struct osmo_ecu_state actually needs and
then using the excess memory to store the private struct of the concrete
ECU implementation.

However, this poses a problem since data[0] is at the end of the struct
it may land in an unaligned position. This also means that the struct we
store there is also unaligned.

We should fix this enclosing the public struct osmo_ecu_state into our
private struct fr_ecu_state. Then we can use container_of to cast from
osmo_ecu_state to fr_ecu_state and correct alignment is ensured as well.

Related: OS#6286
Change-Id: I28672856e8e8f47e04ffe09ee3e07b577108cdc7