netdev-afxdp: Disable -Wfree-nonheap-object on receive.

GCC 11+ generates a warning:

  In file included from lib/netdev-linux-private.h:30,
                   from lib/netdev-afxdp.c:19:
  In function 'dp_packet_delete',
      inlined from 'dp_packet_delete' at lib/dp-packet.h:246:1,
      inlined from 'dp_packet_batch_add__' at lib/dp-packet.h:775:9,
      inlined from 'dp_packet_batch_add' at lib/dp-packet.h:783:5,
      inlined from 'netdev_afxdp_rxq_recv' at lib/netdev-afxdp.c:898:9:
  lib/dp-packet.h:260:9: warning: 'free' called on pointer
    '*umem.xpool.array' with nonzero offset [8, 2558044588346441168]
    [-Wfree-nonheap-object]
    260 |         free(b);
        |         ^~~~~~~

But it is a false positive since the code path is not possible.
In this call chain the packet will always have source DPBUF_AFXDP
and the free() will never be called.  GCC doesn't see that, because
initialization function dp_packet_use_afxdp() is part of a different
translation unit.

Disabling a warning in this particular place to avoid build failures.

Older versions of clang do not have the -Wfree-nonheap-object, so we
need to additionally guard the pragmas.  Clang is using GCC pragmas
and complains about unknown ones.

Reported-at: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108187
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

0 files changed, 0 insertions, 0 deletions