Currently, building bpf samples will cause the following error.

    ./tools/lib/bpf/bpf.h:132:27: error: 'UINT32_MAX' undeclared here (not in a function) ..
     #define BPF_LOG_BUF_SIZE (UINT32_MAX >> 8) /* verifier maximum in kernels <= 5.1 */
                               ^
    ./samples/bpf/bpf_load.h:31:25: note: in expansion of macro 'BPF_LOG_BUF_SIZE'
     extern char bpf_log_buf[BPF_LOG_BUF_SIZE];
                             ^~~~~~~~~~~~~~~~

Due to commit 4519efa6 ("libbpf: fix BPF_LOG_BUF_SIZE off-by-one error")
hard-coded size of BPF_LOG_BUF_SIZE has been replaced with UINT32_MAX which is
defined in <stdint.h> header.

Even with this change, bpf selftests are running fine since these are built
with clang and it includes header(-idirafter) from clang/6.0.0/include.
(it has <stdint.h>)

    clang -I. -I./include/uapi -I../../../include/uapi -idirafter /usr/local/include -idirafter /usr/include \
    -idirafter /usr/lib/llvm-6.0/lib/clang/6.0.0/include -idirafter /usr/include/x86_64-linux-gnu \
    -Wno-compare-distinct-pointer-types -O2 -target bpf -emit-llvm -c progs/test_sysctl_prog.c -o - | \
    llc -march=bpf -mcpu=generic  -filetype=obj -o /linux/tools/testing/selftests/bpf/test_sysctl_prog.o

But bpf samples are compiled with GCC, and it only searches and includes
headers declared at the target file. As '#include <stdint.h>' hasn't been
declared in tools/lib/bpf/bpf.h, it causes build failure of bpf samples.

    gcc -Wp,-MD,./samples/bpf/.sockex3_user.o.d -Wall -Wmissing-prototypes -Wstrict-prototypes \
    -O2 -fomit-frame-pointer -std=gnu89 -I./usr/include -I./tools/lib/ -I./tools/testing/selftests/bpf/ \
    -I./tools/  lib/ -I./tools/include -I./tools/perf -c -o ./samples/bpf/sockex3_user.o ./samples/bpf/sockex3_user.c;

This commit add declaration of '#include <stdint.h>' to tools/lib/bpf/bpf.h
to fix this problem.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Daniel Borkmann says:

====================
Two small fixes in relation to global data handling. Thanks!
====================
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Ran into it while testing; in bpf_object__init_maps() data can be NULL
in the case where no map section is present. Therefore we simply cannot
access data->d_size before NULL test. Move the pr_debug() where it's
safe to access.

Fixes: d859900c ("bpf, libbpf: support global data/bss/rodata sections")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Andrii reported a corner case where e.g. global static data is present
in the BPF ELF file in form of .data/.bss/.rodata section, but without
any relocations to it. Such programs could be loaded before commit
d859900c ("bpf, libbpf: support global data/bss/rodata sections"),
whereas afterwards if kernel lacks support then loading would fail.

Add a probing mechanism which skips setting up libbpf internal maps
in case of missing kernel support. In presence of relocation entries,
we abort the load attempt.

Fixes: d859900c ("bpf, libbpf: support global data/bss/rodata sections")
Reported-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Willem de Bruijn says:

====================
Expand the tc tunnel encap support with protocols that convert the
network layer protocol, such as 6in4. This is analogous to existing
support in bpf_skb_proto_6_to_4.

Patch 1 implements the straightforward logic
Patch 2 tests it with a 6in4 tunnel

Changes v1->v2
  - improve documentation in test
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

So far, all BPF tc tunnel testcases encapsulate in the same network
protocol. Add an encap testcase that requires updating skb->protocol.

The 6in4 tunnel encapsulates an IPv6 packet inside an IPv4 tunnel.
Verify that bpf_skb_net_grow correctly updates skb->protocol to
select the right protocol handler in __netif_receive_skb_core.

The BPF program should also manually update the link layer header to
encode the right network protocol.

Changes v1->v2
  - improve documentation of non-obvious logic
Signed-off-by: Willem de Bruijn <willemb@google.com>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Some tunnels, like sit, change the network protocol of packet.
If so, update skb->protocol to match the new type.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Stanislav Fomichev says:

====================
Currently, when eth_get_headlen calls flow dissector, it doesn't pass any
skb. Because we use passed skb to lookup associated networking namespace
to find whether we have a BPF program attached or not, we always use
C-based flow dissector in this case.

The goal of this patch series is to add new networking namespace argument
to the eth_get_headlen and make BPF flow dissector programs be able to
work in the skb-less case.

The series goes like this:
* use new kernel context (struct bpf_flow_dissector) for flow dissector
  programs; this makes it easy to distinguish between skb and no-skb
  case and supports calling BPF flow dissector on a chunk of raw data
* convert BPF_PROG_TEST_RUN to use raw data
* plumb network namespace into __skb_flow_dissect from all callers
* handle no-skb case in __skb_flow_dissect
* update eth_get_headlen to include net namespace argument and
  convert all existing users
* add selftest to make sure bpf_skb_load_bytes is not allowed in
  the no-skb mode
* extend test_progs to exercise skb-less flow dissection as well
* stop adjusting nhoff/thoff by ETH_HLEN in BPF_PROG_TEST_RUN

v6:
* more suggestions by Alexei:
  * eth_get_headlen now takes net dev, not net namespace
  * test skb-less case via tun eth_get_headlen
* fix return errors in bpf_flow_load
* don't adjust nhoff/thoff by ETH_HLEN

v5:
* API changes have been submitted via bpf/stable tree

v4:
* prohibit access to vlan fields as well (otherwise, inconsistent
  between skb/skb-less cases)
* drop extra unneeded check for skb->vlan_present in bpf_flow.c

v3:
* new kernel xdp_buff-like context per Alexei suggestion
* drop skb_net helper
* properly clamp flow_keys->nhoff

v2:
* moved temporary skb from stack into percpu (avoids memset of ~200 bytes
  per packet)
* tightened down access to __sk_buff fields from flow dissector programs to
  avoid touching shinfo (whitelist only relevant fields)
* addressed suggestions from Willem
====================
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Now that we use skb-less flow dissector let's return true nhoff and
thoff. We used to adjust them by ETH_HLEN because that's how it was
done in the skb case. For VLAN tests that looks confusing: nhoff is
pointing to vlan parts :-\

Warning, this is an API change for BPF_PROG_TEST_RUN! Feel free to drop
if you think that it's too late at this point to fix it.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Right now we incorrectly return 'ret' which is always zero at that
point.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Export last_dissection map from flow dissector and use a known place in
tun driver to trigger BPF flow dissection.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

When flow dissector is called without skb, we want to make sure
bpf_skb_load_bytes invocations return error. Add small test which tries
to read single byte from a packet.

bpf_skb_load_bytes should always fail under BPF_PROG_TEST_RUN because
it was converted to the skb-less mode.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Update all users of eth_get_headlen to pass network device, fetch
network namespace from it and pass it down to the flow dissector.
This commit is a noop until administrator inserts BPF flow dissector
program.

Cc: Maxim Krasnyansky <maxk@qti.qualcomm.com>
Cc: Saeed Mahameed <saeedm@mellanox.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: intel-wired-lan@lists.osuosl.org
Cc: Yisen Zhuang <yisen.zhuang@huawei.com>
Cc: Salil Mehta <salil.mehta@huawei.com>
Cc: Michael Chan <michael.chan@broadcom.com>
Cc: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

When called without skb, gather all required data from the
__skb_flow_dissect's arguments and use recently introduces
no-skb mode of bpf flow dissector.

Note: WARN_ON_ONCE(!net) will now trigger for eth_get_headlen users.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

This new argument will be used in the next patches for the
eth_get_headlen use case. eth_get_headlen calls flow dissector
with only data (without skb) so there is currently no way to
pull attached BPF flow dissector program. With this new argument,
we can amend the callers to explicitly pass network namespace
so we can use attached BPF program.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Now that we have bpf_flow_dissect which can work on raw data,
use it when doing BPF_PROG_TEST_RUN for flow dissector.

Simplifies bpf_prog_test_run_flow_dissector and allows us to
test no-skb mode.

Note, that previously, with bpf_flow_dissect_skb we used to call
eth_type_trans which pulled L2 (ETH_HLEN) header and we explicitly called
skb_reset_network_header. That means flow_keys->nhoff would be
initialized to 0 (skb_network_offset) in init_flow_keys.
Now we call bpf_flow_dissect with nhoff set to ETH_HLEN and need
to undo it once the dissection is done to preserve the existing behavior.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

struct bpf_flow_dissector has a small subset of sk_buff fields that
flow dissector BPF program is allowed to access and an optional
pointer to real skb. Real skb is used only in bpf_skb_load_bytes
helper to read non-linear data.

The real motivation for this is to be able to call flow dissector
from eth_get_headlen context where we don't have an skb and need
to dissect raw bytes.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

All we do is write the length/status and address bits to a DMA
descriptor only to write its contents into on-chip registers right
after, eliminate this unnecessary step.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a bridge port is being deleted, do not dereference it later in
br_vlan_port_event() as it can result in a use-after-free [1] if the RCU
callback was executed before invoking the function.

[1]
[  129.638551] ==================================================================
[  129.646904] BUG: KASAN: use-after-free in br_vlan_port_event+0x53c/0x5fd
[  129.654406] Read of size 8 at addr ffff8881e4aa1ae8 by task ip/483
[  129.663008] CPU: 0 PID: 483 Comm: ip Not tainted 5.1.0-rc5-custom-02265-ga946bd73daac #1383
[  129.672359] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[  129.682484] Call Trace:
[  129.685242]  dump_stack+0xa9/0x10e
[  129.689068]  print_address_description.cold.2+0x9/0x25e
[  129.694930]  kasan_report.cold.3+0x78/0x9d
[  129.704420]  br_vlan_port_event+0x53c/0x5fd
[  129.728300]  br_device_event+0x2c7/0x7a0
[  129.741505]  notifier_call_chain+0xb5/0x1c0
[  129.746202]  rollback_registered_many+0x895/0xe90
[  129.793119]  unregister_netdevice_many+0x48/0x210
[  129.803384]  rtnl_delete_link+0xe1/0x140
[  129.815906]  rtnl_dellink+0x2a3/0x820
[  129.844166]  rtnetlink_rcv_msg+0x397/0x910
[  129.868517]  netlink_rcv_skb+0x137/0x3a0
[  129.882013]  netlink_unicast+0x49b/0x660
[  129.900019]  netlink_sendmsg+0x755/0xc90
[  129.915758]  ___sys_sendmsg+0x761/0x8e0
[  129.966315]  __sys_sendmsg+0xf0/0x1c0
[  129.988918]  do_syscall_64+0xa4/0x470
[  129.993032]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  129.998696] RIP: 0033:0x7ff578104b58
...
[  130.073811] Allocated by task 479:
[  130.077633]  __kasan_kmalloc.constprop.5+0xc1/0xd0
[  130.083008]  kmem_cache_alloc_trace+0x152/0x320
[  130.088090]  br_add_if+0x39c/0x1580
[  130.092005]  do_set_master+0x1aa/0x210
[  130.096211]  do_setlink+0x985/0x3100
[  130.100224]  __rtnl_newlink+0xc52/0x1380
[  130.104625]  rtnl_newlink+0x6b/0xa0
[  130.108541]  rtnetlink_rcv_msg+0x397/0x910
[  130.113136]  netlink_rcv_skb+0x137/0x3a0
[  130.117538]  netlink_unicast+0x49b/0x660
[  130.121939]  netlink_sendmsg+0x755/0xc90
[  130.126340]  ___sys_sendmsg+0x761/0x8e0
[  130.130645]  __sys_sendmsg+0xf0/0x1c0
[  130.134753]  do_syscall_64+0xa4/0x470
[  130.138864]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[  130.146195] Freed by task 0:
[  130.149421]  __kasan_slab_free+0x125/0x170
[  130.154016]  kfree+0xf3/0x310
[  130.157349]  kobject_put+0x1a8/0x4c0
[  130.161363]  rcu_core+0x859/0x19b0
[  130.165175]  __do_softirq+0x250/0xa26
[  130.170956] The buggy address belongs to the object at ffff8881e4aa1ae8
                which belongs to the cache kmalloc-1k of size 1024
[  130.184972] The buggy address is located 0 bytes inside of
                1024-byte region [ffff8881e4aa1ae8, ffff8881e4aa1ee8)

Fixes: 9c0ec2e7 ("bridge: support binding vlan dev link state to vlan member bridge ports")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Cc: Mike Manning <mmanning@vyatta.att-mail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Mike Manning <mmanning@vyatta.att-mail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Without this patch the socket address family sporadically gets wrong
value ends up the dev_set_mac_address() fails to set the desired MAC
address.

Fixes: 25766271 ("r8152: Refresh MAC address during USBDEVFS_RESET")
Signed-off-by: Crag.Wang <crag.wang@dell.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-By: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Shared buffer improvements

This patchset includes two improvements with regards to shared buffer
configuration in mlxsw.

The first part of this patchset forbids the user from performing illegal
shared buffer configuration that can result in unnecessary packet loss.
In order to better communicate these configuration failures to the user,
extack is propagated from devlink towards drivers. This is done in
patches #1-#8.

The second part of the patchset deals with the shared buffer
configuration of the CPU port. When a packet is trapped by the device,
it is sent across the PCI bus to the attached host CPU. From the
device's perspective, it is as if the packet is transmitted through the
CPU port.

While testing traffic directed at the CPU it became apparent that for
certain packet sizes and certain burst sizes, the current shared buffer
configuration of the CPU port is inadequate and results in packet drops.
The configuration is adjusted by patches #9-#14 that create two new pools
- ingress & egress - which are dedicated for CPU traffic.
====================
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Switch the CPU port to use the new dedicated egress pool instead the
previously used egress pool which was shared with normal front panel
ports.

Add per-port quotas for the amount of traffic that can be buffered for
the CPU port and also adjust the per-{port, TC} quotas.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The CPU port is used to transmit traffic that is trapped to the host
CPU. It is therefore irrelevant to define ingress quota for it.

Add a 'skip_ingress' argument to the function tasked with configuring
per-port quotas, so that ingress quotas could be skipped in case the
passed local port is the CPU port.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function is used to set the per-port shared buffer quotas.
Currently, these quotas are only set for front panel ports, but a
subsequent patch will configure these quotas for the CPU port as well.

The configuration required for the CPU port is a bit different than that
of the front panel ports, so split the business logic into a separate
function which will be called with different parameters for the CPU
port.

No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the new ingress pool that was added in the previous patch for
control packets (e.g., STP, LACP) that are trapped to the CPU.

The previous management pool is no longer necessary and therefore its
size is set to 0.

The maximum quota for traffic towards the CPU is increased to 50% of the
free space in the new ingress pool and therefore the reserved space is
reduced by half, to 10KB - in both the shared and headroom buffer. This
allows for more efficient utilization of the shared buffer as reserved
space cannot be used for other purposes.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Packets that are trapped to the CPU are transmitted through the CPU port
to the attached host. The CPU port is therefore like any other port and
needs to have shared buffer configuration.

The maximum quotas configured for the CPU are provided using dynamic
threshold and cannot be changed by the user. In order to make sure that
these thresholds are always valid, the configuration of the threshold
type of these pools is forbidden.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code currently assumes that ingress pools have lower indices than
egress pools. This makes it impossible to add more ingress pools
without breaking user configuration that relies on a certain pool index
to correspond to an egress pool.

Remove such assumptions from the code, so that more ingress pools could
be added by subsequent patches.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit e83c045e ("mlxsw: spectrum_buffers: Configure MC pool")
configured the threshold of the multicast TCs as infinite so that the
admission of multicast packets is only depended on per-switch priority
threshold.

Forbid the user from changing the thresholds of these multicast TCs and
their binding to a different pool.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Multicast packets have three egress quotas:
* Per egress port
* Per egress port and traffic class
* Per switch priority

The limits on the switch priority are not exposed to the user and
specified as dynamic threshold on the first egress pool.

Forbid changing the threshold type of the first egress pool so that
these limits are always valid.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit e83c045e ("mlxsw: spectrum_buffers: Configure MC pool") added
a dedicated pool for multicast traffic. The pool is visible to the user
so that it would be possible to monitor its occupancy, but its
configuration should be forbidden in order to maintain its intended
operation.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Subsequent patches are going to need to veto changes in certain TCs'
binding and threshold configurations.

Add fields to the TC's struct that indicate if the TC can be bound to a
different pool and whether its threshold can change and enforce that.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Subsequent patches are going to need to veto changes in certain pools'
size and / or threshold type (mode).

Add two fields to the pool's struct that indicate if either of these
attributes is allowed to change and enforce that.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The pool indices are currently hard coded throughout the code, which
makes the code hard to follow and extend.

Overcome this by using defines for the pool indices.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add extack messages to better communicate invalid configuration to the
user.

Example:

# devlink sb pool set pci/0000:01:00.0 pool 0 size 104857600 thtype dynamic
Error: mlxsw_spectrum: Exceeded shared buffer size.
devlink answers: Invalid argument
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add extack to shared buffer set operations, so that meaningful error
messages could be propagated to the user.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Paul Gortmaker says:

====================
clean up needless use of module infrastructure

People can embed modular includes and modular exit functions into code
that never use any of it, and they won't get any errors or warnings.

Using modular infrastructure in non-modules might seem harmless, but some
of the downfalls this leads to are:

 (1) it is easy to accidentally write unused module_exit removal code
 (2) it can be misleading when reading the source, thinking a driver can
     be modular when the Makefile and/or Kconfig prohibit it
 (3) an unused include of the module.h header file will in turn
     include nearly everything else; adding a lot to CPP overhead.
 (4) it gets copied/replicated into other drivers and spreads quickly.

As a data point for #3 above, an empty C file that just includes the
module.h header generates over 750kB of CPP output.  Repeating the same
experiment with init.h and the result is less than 12kB; with export.h
it is only about 1/2kB; with both it still is less than 12kB.  One driver
in this series gets the module.h ---> init.h+export.h conversion.

Worse, are headers in include/linux that in turn include <linux/module.h>
as they can impact a whole fleet of drivers, or a whole subsystem, so
special care should be used in order to avoid that.  Such headers should
only include what they need to be stand-alone; they should not be trying
to anticipate the various header needs of their possible end users.

In this series, four include/linux headers have module.h removed from
them because they don't strictly need it.  Then three chunks of net
related code have modular infrastructure that isn't used, removed.

There are no runtime changes, so the biggest risk is a genuine consumer
of module.h content relying on implicitly getting it from one of the
include/linux instances removed here - thus resulting in a build fail.

With that in mind, allmodconfig build testing was done on x86-64, arm64,
x86-32, arm. powerpc, and mips on linux-next (and hence net-next).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The Kconfig currently controlling compilation of this code is:

net/strparser/Kconfig:config STREAM_PARSER
net/strparser/Kconfig:  def_bool n

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.  For
clarity, we change the fcn name mod_init to dev_init at the same time.

We replace module.h with init.h and export.h ; the latter since this
file exports some syms.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Kconfig controlling this code is:

bpfilter/Kconfig:menuconfig BPFILTER
bpfilter/Kconfig:   bool "BPF based packet filtering framework (BPFILTER)"

Since it isn't a module, we shouldn't use module_init().  Instead we
use device_initcall() - which is exactly what module_init() defaults
to for non-modular code/builds.

We don't remove <linux/module.h> from the includes since this file does
a request_module() and hence is a valid user of that header file, even
though it is not modular itself.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Kconfig currently controlling compilation of this code is:

net/Kconfig:config CGROUP_NET_PRIO
net/Kconfig:    bool "Network priority cgroup"

...meaning that it currently is not being built as a module by anyone,
as module support was discontinued in 2014.

We delete the MODULE_LICENSE tag since all that information is already
contained at the top of the file in the comments.

We don't delete module.h from the includes since it was no longer there
to begin with.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rosen, Rami" <rami.rosen@intel.com>
Cc: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: netdev@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ideally, header files under include/linux shouldn't be adding
includes of other headers, in anticipation of their consumers,
but just the headers needed for the header itself to pass
parsing with CPP.

The module.h is particularly bad in this sense, as it itself does
include a whole bunch of other headers, due to the complexity of
module support.

Since tc_ife.h is not going into a module struct looking for
specific fields, we can just let it know that module is a struct,
just like about 60 other include/linux headers already do.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>