Basically, dev_ifsioc() operates on the passed single netns (except
for netdev notifier chains with lower/upper devices for which we will
need more changes).

Let's hold rtnl_net_lock() for dev_ifsioc().

Now that NETDEV_CHANGENAME is always triggered under rtnl_net_lock()
of the device's netns. (do_setlink() and dev_ifsioc())

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250115095545.52709-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

kernel test robot reported section mismatch in rtnl_net_debug_exit().

  WARNING: modpost: vmlinux: section mismatch in reference: rtnl_net_debug_exit+0x20 (section: .exit.text) -> rtnl_net_debug_net_ops (section: .init.data)

rtnl_net_debug_exit() uses rtnl_net_debug_net_ops() that is annotated
as __net_initdata, but this file is always built-in.

Let's remove rtnl_net_debug_exit().

Fixes: 03fa53485659 ("rtnetlink: Add ASSERT_RTNL_NET() placeholder for netdev notifier.")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410101854.i0vQCaDz-lkp@intel.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241010172433.67694-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

The global and per-netns netdev notifier depend on RTNL, and its
dependency is not so clear due to nested calls.

Let's add a placeholder to place ASSERT_RTNL_NET() for each event.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>