ERROR:root:In file included from ../net/ethtool/common.c:8:
../include/linux/phy_link_topology.h:110:1: error: return type defaults to ‘int’ [-Wimplicit-int]
  110 | phy_link_topo_get_port(struct net_device *dev, u32 port_id)
      | ^~~~~~~~~~~~~~~~~~~~~~
../include/linux/phy_link_topology.h:110:1: warning: no previous prototype for ‘phy_link_topo_get_port’ [-Wmissing-prototypes]
In file included from ../include/uapi/linux/posix_types.h:5,
                 from ../include/uapi/linux/types.h:14,
                 from ../include/linux/types.h:6,
                 from ../include/linux/kasan-checks.h:5,
                 from ../include/asm-generic/rwonce.h:26,
                 from ./arch/x86/include/generated/asm/rwonce.h:1,
                 from ../include/linux/compiler.h:380,
                 from ../include/linux/build_bug.h:5,
                 from ../include/linux/bits.h:30,
                 from ../include/linux/bitops.h:6,
                 from ../include/linux/bitmap.h:8,
                 from ../include/linux/ethtool.h:16,
                 from ../include/uapi/linux/ethtool_netlink.h:12,
                 from ../include/linux/ethtool_netlink.h:6,
                 from ../net/ethtool/common.c:3:
../include/linux/phy_link_topology.h: In function ‘phy_link_topo_get_port’:
../include/linux/stddef.h:8:14: error: returning ‘void *’ from a function with return type ‘int’ makes integer from pointer without a cast [-Wint-conversion]
    8 | #define NULL ((void *)0)
      |              ^
../include/linux/phy_link_topology.h:112:16: note: in expansion of macro ‘NULL’
  112 |         return NULL;
      |                ^~~~
make[5]: *** [../scripts/Makefile.build:287: net/ethtool/common.o] Error 1
make[5]: *** Waiting for unfinished jobs....
In file included from ../net/ethtool/netlink.c:7:
../include/linux/phy_link_topology.h:110:1: error: return type defaults to ‘int’ [-Wimplicit-int]
  110 | phy_link_topo_get_port(struct net_device *dev, u32 port_id)
      | ^~~~~~~~~~~~~~~~~~~~~~
../include/linux/phy_link_topology.h:110:1: warning: no previous prototype for ‘phy_link_topo_get_port’ [-Wmissing-prototypes]
In file included from ../include/uapi/linux/posix_types.h:5,
                 from ../include/uapi/linux/types.h:14,
                 from ../include/linux/types.h:6,
                 from ../include/linux/lockdep_types.h:13,
                 from ../include/linux/lockdep.h:13,
                 from ../include/net/netdev_lock.h:6,
                 from ../net/ethtool/netlink.c:3:
../include/linux/phy_link_topology.h: In function ‘phy_link_topo_get_port’:
../include/linux/stddef.h:8:14: error: returning ‘void *’ from a function with return type ‘int’ makes integer from pointer without a cast [-Wint-conversion]
    8 | #define NULL ((void *)0)
      |              ^
../include/linux/phy_link_topology.h:112:16: note: in expansion of macro ‘NULL’
  112 |         return NULL;
      |                ^~~~
make[5]: *** [../scripts/Makefile.build:287: net/ethtool/netlink.o] Error 1
make[4]: *** [../scripts/Makefile.build:544: net/ethtool] Error 2
make[4]: *** Waiting for unfinished jobs....
In file included from ../net/core/dev.c:165:
../include/linux/phy_link_topology.h:110:1: error: return type defaults to ‘int’ [-Wimplicit-int]
  110 | phy_link_topo_get_port(struct net_device *dev, u32 port_id)
      | ^~~~~~~~~~~~~~~~~~~~~~
../include/linux/phy_link_topology.h:110:1: warning: no previous prototype for ‘phy_link_topo_get_port’ [-Wmissing-prototypes]
In file included from ../include/uapi/linux/posix_types.h:5,
                 from ../include/uapi/linux/types.h:14,
                 from ../include/linux/types.h:6,
                 from ../include/linux/kasan-checks.h:5,
                 from ../include/asm-generic/rwonce.h:26,
                 from ./arch/x86/include/generated/asm/rwonce.h:1,
                 from ../include/linux/compiler.h:380,
                 from ../include/linux/cleanup.h:5,
                 from ../include/linux/uaccess.h:5,
                 from ../net/core/dev.c:71:
../include/linux/phy_link_topology.h: In function ‘phy_link_topo_get_port’:
../include/linux/stddef.h:8:14: error: returning ‘void *’ from a function with return type ‘int’ makes integer from pointer without a cast [-Wint-conversion]
    8 | #define NULL ((void *)0)
      |              ^
../include/linux/phy_link_topology.h:112:16: note: in expansion of macro ‘NULL’
  112 |         return NULL;
      |                ^~~~
make[5]: *** [../scripts/Makefile.build:287: net/core/dev.o] Error 1
make[5]: *** Waiting for unfinished jobs....
make[4]: *** [../scripts/Makefile.build:544: net/core] Error 2
make[3]: *** [../scripts/Makefile.build:544: net] Error 2
make[3]: *** Waiting for unfinished jobs....
make[2]: *** [/srv/nipa-kunit/testing/Makefile:2054: .] Error 2
make[1]: *** [/srv/nipa-kunit/testing/Makefile:248: __sub-make] Error 2
make: *** [Makefile:248: __sub-make] Error 2