proc_fs was used, in af_packet, without a surrounding #ifdef,
although there is no hard dependency on proc_fs.
That caused the initialization of the af_packet module to fail
when CONFIG_PROC_FS=n.
Specifically, proc_create_net() was used in af_packet.c,
and when it fails, packet_net_init() returns -ENOMEM.
It will always fail when the kernel is compiled without proc_fs,
because, proc_create_net() for example always returns NULL.
The calling order that starts in af_packet.c is as follows:
packet_init()
register_pernet_subsys()
register_pernet_operations()
__register_pernet_operations()
ops_init()
ops->init() (packet_net_ops.init=packet_net_init())
proc_create_net()
It worked in the past because register_pernet_subsys()'s return value
wasn't checked before this Commit 36096f2f4f ("packet: Fix error path in
packet_init.").
It always returned an error, but was not checked before, so everything
was working even when CONFIG_PROC_FS=n.
The fix here is simply to add the necessary #ifdef.
This also fixes a similar error in tls_proc.c, that was found by Jakub
Kicinski.
Fixes: d26b698dd3 ("net/tls: add skeleton of MIB statistics")
Fixes: 36096f2f4f ("packet: Fix error path in packet_init")
Signed-off-by: Yonatan Linik <yonatanlinik@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
a268e0f245