Aspects of bit fields are 'implementation defined'. On some platforms
alignment will occur if two adjacent fields are of different types. This
occurs in spdk_nvme_feat_async_event_configutation after the crit_warn
member which is effectively an int8_t, followed by an int16_t. There
isn't a generic way of changing the compiler's behaviour, so the best
options are:
- Change crit_warn to a uint32_t bit field and copy the value to/from
a spdk_nvme_critical_warning_state variable to use it. This requires
changes to code using the field.
- Adjust the structure definition to use smaller types to avoid the
problem. This preserves existing semantics, but the field order will
need to be reviewed if big-endian support is ever added (other places
in nvme_spec.h will need similar attention). A second reserved field
is required.
Use smaller types which seems the most straightforward option. Adjust
the use of the spdk_nvme_feat_async_event_configuration reserved fields
in lib/nvmf/ctrlr.c.
The new structure is binary compatible and the fields behave in the same
way, with the exception of an additional reserved field, so updating
CHANGELOG.md probably isn't necessary.
Signed-off-by: Nick Connolly <nick.connolly@mayadata.io>
Change-Id: I7d8163c84b4f410fc95a5b7064506ad7b4b62c6c
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/6340
Community-CI: Broadcom CI
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>
68ff34bc66