Re: [PATCH v2] RDMA: Directly cast the sockaddr union to sockaddr

[Simon Horman]

On Mon, May 13, 2019 at 09:55:21PM -0300, Jason Gunthorpe wrote:
> gcc 9 now does allocation size tracking and thinks that passing the member
> of a union and then accessing beyond that member's bounds is an overflow.
> 
> Instead of using the union member, use the entire union with a cast to
> get to the sockaddr. gcc will now know that the memory extends the full
> size of the union.
> 
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> ---
>  drivers/infiniband/core/addr.c           | 16 ++++++++--------
>  drivers/infiniband/hw/ocrdma/ocrdma_ah.c |  5 ++---
>  drivers/infiniband/hw/ocrdma/ocrdma_hw.c |  5 ++---
>  3 files changed, 12 insertions(+), 14 deletions(-)
> 
> I missed the ocrdma files in the v1
> 
> We can revisit what to do with that repetitive union after the merge
> window, but this simple patch will eliminate the warnings for now.
> 
> Linus, I'll send this as a PR tomorrow - there is also a bug fix for
> the rdma-netlink changes posted that should go too.

<2c>
I would be very happy to see this revisited in such a way
that some use is made of the C type system (instead of casts).
</2c>