Re: [PATCH for-8.1] hw/rdma/vmw/pvrdma_cmd: Use correct struct in query_port()

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 25/7/23 13:36, Peter Maydell wrote:
> In query_port() we pass the address of a local pvrdma_port_attr
> struct to the rdma_query_backend_port() function.  Unfortunately,
> rdma_backend_query_port() wants a pointer to a struct ibv_port_attr,
> and the two are not the same length.
> 
> Coverity spotted this (CID 1507146): pvrdma_port_attr is 48 bytes
> long, and ibv_port_attr is 52 bytes, because it has a few extra
> fields at the end.
> 
> Fortunately, all we do with the attrs struct after the call is to
> read a few specific fields out of it which are all at the same
> offsets in both structs, so we can simply make the local variable the
> correct type.  This also lets us drop the cast (which should have
> been a bit of a warning flag that we were doing something wrong
> here).

Fortunate but also kind of amusing :)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> Cc: qemu-stable@nongnu.org
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> I don't know anything about the rdma code so this fix is based
> purely on looking at the code, and is untested beyond just
> make check/make check-avocado.
> ---
>   hw/rdma/vmw/pvrdma_cmd.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)