Re: [PATCH 1/2] migration: Assert that migrate_multifd_compression() returns an in-range value

[Juan Quintela]

Peter Maydell <peter.maydell@linaro.org> wrote:
> Coverity complains that when we use the return value from
> migrate_multifd_compression() as an array index:
>   multifd_recv_state->ops = multifd_ops[migrate_multifd_compression()];
>
> that this might overrun the array (which is declared to have size
> MULTIFD_COMPRESSION__MAX).  This is because the function return type
> is MultiFDCompression, which is an autogenerated enum.  The code
> generator includes the "one greater than the maximum possible value"
> MULTIFD_COMPRESSION__MAX in the enum, even though this is not
> actually a valid value for the enum, and this makes Coverity think
> that migrate_multifd_compression() could return that __MAX value and
> index off the end of the array.
>
> Suppress the Coverity error by asserting that the value we're going
> to return is within range.
>
> Resolves: Coverity CID 1487239, 1487254
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Juan Quintela <quintela@redhat.com>