Put the mdiodev after xpcs_create() so that the XPCS driver can manage
the lifetime of the mdiodev its using.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Maxime Chevallier says:

====================
net: add a regmap-based mdio driver and drop TSE PCS

This is the V4 of a series that follows-up on the work [1] aiming to drop the
altera TSE PCS driver, as it turns out to be a version of the Lynx PCS exposed
as a memory-mapped block, instead of living on an MDIO bus.

One step of this removal involved creating a regmap-based mdio driver
that translates MDIO accesses into the actual underlying bus that
exposes the register. The register layout must of course match the
standard MDIO layout, but we can now account for differences in stride
with recent work on the regmap subsystem [2].

Sorry for repeating this, but I didn't hear anything on this matter in previous
iterations, Mark, Net maintainers, this series depends on the patch
e12ff287 that was recently merged into the regmap tree [3].

For this series to be usable in net-next, this patch must be applied
beforehand. Should Mark create a tag that would then be merged into
net-next ? Or should we just wait for the next release to merge this
into net-next ?

This series introduces a new MDIO driver, and uses it to convert Altera
TSE from the actual TSE PCS driver to Lynx PCS.

Since it turns out dwmac_socfpga also uses a TSE PCS block, port that
driver to Lynx as well.

Changes in V4 :
 - Use new pcs_lynx_create/destroy helpers added by Russell
 - Rework the cleanup sequence to avoid leaking data
 - Rework a bit KConfig to properly select dependencies
 - Fix a few hiccups with misplaced hunks in 2 commits

Changes in V3 :
 - Use a dedicated struct for the mii bus's priv data, to avoid
   duplicating the whole struct mdio_regmap_config, from which 2 fields
   only are necessary after init, as suggested by Russell
 - Use ~0 instead of ~0UL for the no-scan bitmask, following Simon's
   review.

Changes in V2 :
 - Use phy_mask to avoid unnecessarily scanning the whole mdio bus
 - Go one step further and completely disable scanning if users
   set the .autoscan flag to false, in case the mdiodevice isn't an
   actual PHY (a PCS for example).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

dwmac_socfpga re-implements support for the TSE PCS, which is identical
to the already existing TSE PCS, which in turn is the same as the Lynx
PCS. Drop the existing TSE re-implemenation and use the Lynx PCS
instead, relying on the regmap-mdio driver to translate MDIO accesses
into mmio accesses.

Add a lynx_pcs reference in the stmmac's internal structure, and use
.mac_select_pcs() to return the relevant PCS to be used.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that we can easily create a mdio-device that represents a
memory-mapped device that exposes an MDIO-like register layout, we don't
need the Altera TSE PCS anymore, since we can use the Lynx PCS instead.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The newly introduced regmap-based MDIO driver allows for an easy mapping
of an mdiodevice onto the memory-mapped TSE PCS, which is actually a
Lynx PCS.

Convert Altera TSE to use this PCS instead of the pcs-altera-tse, which
is nothing more than a memory-mapped Lynx PCS.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There exists several examples today of devices that embed an ethernet
PHY or PCS directly inside an SoC. In this situation, either the device
is controlled through a vendor-specific register set, or sometimes
exposes the standard 802.3 registers that are typically accessed over
MDIO.

As phylib and phylink are designed to use mdiodevices, this driver
allows creating a virtual MDIO bus, that translates mdiodev register
accesses to regmap accesses.

The reason we use regmap is because there are at least 3 such devices
known today, 2 of them are Altera TSE PCS's, memory-mapped, exposed
with a 4-byte stride in stmmac's dwmac-socfpga variant, and a 2-byte
stride in altera-tse. The other one (nxp,sja1110-base-tx-mdio) is
exposed over SPI.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This following message is printed in the console each time a network
device configured with an IPv6 addresses is ready to be used:

  ADDRCONF(NETDEV_CHANGE): <iface>: link becomes ready

When netns are being extensively used -- e.g. by re-creating netns' with
veth to discuss with each others for testing purposes like mptcp_join.sh
selftest does -- it generates a lot of messages like that: more than 700
when executing mptcp_join.sh with the latest version.

It looks like this message is not that helpful after all: maybe it can
be used as a sign to know if there is something wrong, e.g. if a device
is being regularly reconfigured by accident? But even then, there are
better ways to monitor and diagnose such issues.

When looking at commit 3c21edbd ("[IPV6]: Defer IPv6 device
initialization until the link becomes ready.") which introduces this new
message, it seems it had been added to verify that the new feature was
working as expected. It could have then used a lower level than "info"
from the beginning but it was fine like that back then: 17 years ago.

It seems then OK today to simply lower its level, similar to commit
7c62b8dd ("net/ipv6: lower the level of "link is not ready" messages")
and as suggested by Mat [1], Stephen and David [2].

Link: https://lore.kernel.org/mptcp/614e76ac-184e-c553-af72-084f792e60b0@kernel.org/T/ [1]
Link: https://lore.kernel.org/netdev/68035bad-b53e-91cb-0e4a-007f27d62b05@tessares.net/T/ [2]
Suggested-by: Mat Martineau <martineau@kernel.org>
Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Suggested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dan Carpenter reported a signedness bug in genphy_loopback(). Andrew
reports that:

"It is common to get this wrong in general with PHY drivers. Dan
regularly posts fixes like this soon after a PHY driver patch it
merged. I really wish we could somehow get the compiler to warn when
the result from phy_read() is stored into a unsigned type. It would
save Dan a lot of work."

Let's make phy_read*_poll_timeout() immune to further issues when "val"
is an unsigned type by storing the read function's result in a signed
int as well as "val", and using the signed variable both to check for
an error and for propagating that error to the caller.

The advantage of this method is we don't change where the cast from
the signed return code to the user's variable occurs - so users will
see no change.

Previously Heiner changed phy_read_poll_timeout() to check for an error
before evaluating the user supplied condition, but didn't update
phy_read_mmd_poll_timeout(). Make that change there too.

Link: https://lore.kernel.org/r/d7bb312e-2428-45f6-b9b3-59ba544e8b94@kili.mountainSigned-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/E1q4kX6-00BNuM-Mx@rmk-PC.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Jakub Kicinski says:

====================
tools: ynl-gen: dust off the user space code

Every now and then I wish I finished the user space part of
the netlink specs, Python scripts kind of stole the show but
C is useful for selftests and stuff which needs to be fast.
Recently someone asked me how to access devlink and ethtool
from C++ which pushed me over the edge.

Fix things which bit rotted and finish notification handling.
This series contains code gen changes only. I'll follow up
with the fixed component, samples and docs as soon as it's
merged.
====================

Link: https://lore.kernel.org/r/20230602023548.463441-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Notifications may come in at any time. The family must be always
ready to parse a random incoming notification. Generate notification
table for parsing and tell YNL which request we're processing
to distinguish responses from notifications.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We'll want to store static info about the family soon.
Generate a struct. This changes creation from, e.g.:

	 ys = ynl_sock_create("netdev", &yerr);
to:
	 ys = ynl_sock_create(&ynl_netdev_family, &yerr);

on user's side.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We expect user to allocate requests with calloc(),
make things a bit more consistent and provide helpers.
Generate free calls, too.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We generate send() and recv() calls and all msg handling for
each operation. It's a lot of repeated code and will only grow
with notification handling. Call back to a helper YNL lib instead.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

It's sometimes useful to print the name of an enum value,
flag or name of the op. Python can do it, add C helper
code gen for getting names of things.

Example:

  static const char * const netdev_xdp_act_strmap[] = {
	[0] = "basic",
	[1] = "redirect",
	[2] = "ndo-xmit",
	[3] = "xsk-zerocopy",
	[4] = "hw-offload",
	[5] = "rx-sg",
	[6] = "ndo-xmit-sg",
  };

  const char *netdev_xdp_act_str(enum netdev_xdp_act value)
  {
	value = ffs(value) - 1;
	if (value < 0 || value >= (int)MNL_ARRAY_SIZE(netdev_xdp_act_strmap))
		return NULL;
	return netdev_xdp_act_strmap[value];
  }
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Parsing nested types may return an error, propagate it.
Not marking as a fix, because nothing uses YNL upstream.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Both event and notify types are always consistent. Rewrite
the condition checking if we can reuse reply types to be
less picky and let notify thru.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

For pure structs (parsed nested attributes) we track what
forms of the struct exist in request and reply directions.
Make sure we don't overwrite the recorded struct each time,
otherwise the information is lost.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Unused and Pad attributes don't carry information.
Unused should never exist, and be rejected.
Pad should be silently skipped.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Make sure all relevant headers are included, we allocate memory,
use memcpy() and Linux types without including the headers.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Callers of flowi4_update_output() never try to update ->flowi4_tos:

  * ip_route_connect() updates ->flowi4_tos with its own current
    value.

  * ip_route_newports() has two users: tcp_v4_connect() and
    dccp_v4_connect. Both initialise fl4 with ip_route_connect(), which
    in turn sets ->flowi4_tos with RT_TOS(inet_sk(sk)->tos) and
    ->flowi4_scope based on SOCK_LOCALROUTE.

    Then ip_route_newports() updates ->flowi4_tos with
    RT_CONN_FLAGS(sk), which is the same as RT_TOS(inet_sk(sk)->tos),
    unless SOCK_LOCALROUTE is set on the socket. In that case, the
    lowest order bit is set to 1, to eventually inform
    ip_route_output_key_hash() to restrict the scope to RT_SCOPE_LINK.
    This is equivalent to properly setting ->flowi4_scope as
    ip_route_connect() did.

  * ip_vs_xmit.c initialises ->flowi4_tos with memset(0), then calls
    flowi4_update_output() with tos=0.

  * sctp_v4_get_dst() uses the same RT_CONN_FLAGS_TOS() when
    initialising ->flowi4_tos and when calling flowi4_update_output().

In the end, ->flowi4_tos never changes. So let's just drop the tos
parameter. This will simplify the conversion of ->flowi4_tos from __u8
to dscp_t.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The gotos for cleanup aren't required, the function
might as well just return the actual error code.
Signed-off-by: Moritz Fischer <moritzf@google.com>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

No functional modification involved.

net/ipv4/ip_gre.c:192 ipgre_err() warn: inconsistent indenting.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5375Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make sure we don't generate premature POLLIN events.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

TLS does not override .poll() so TLS-enabled socket will generate
an event whenever data arrives at the TCP socket. This leads to
unnecessary wakeups on slow connections.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The test case shown in [1] triggers the kernel to access the null pointer.
Therefore, add related test cases to mq.
The test results are as follows:

./tdc.py -e 0531
1..1
ok 1 0531 - Replace mq with invalid parent ID

./tdc.py -c mq
1..8
ok 1 ce7d - Add mq Qdisc to multi-queue device (4 queues)
ok 2 2f82 - Add mq Qdisc to multi-queue device (256 queues)
ok 3 c525 - Add duplicate mq Qdisc
ok 4 128a - Delete nonexistent mq Qdisc
ok 5 03a9 - Delete mq Qdisc twice
ok 6 be0f - Add mq Qdisc to single-queue device
ok 7 1023 - Show mq class
ok 8 0531 - Replace mq with invalid parent ID

[1] https://lore.kernel.org/all/20230527093747.3583502-1-shaozhengchao@huawei.com/Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Link: https://lore.kernel.org/r/20230601012250.52738-1-shaozhengchao@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add the ability to read the PHY maintained LPI counter which is in the
Clause 45 vendor space, device address 7, offset 0x803F. The counter is
cleared on read.
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230531231729.1873932-1-florian.fainelli@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In addition to properly handling probe deferrals dev_err_probe()
conveniently combines printing an error message with returning
the errno. So let's use it for every error path in rtl_init_one()
to simplify the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/f0596a19-d517-e301-b649-304f9247b75a@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Oleksij Rempel says:

====================
Extend dt-bindings for PSE-PD controllers and update prtt1c dts

This patch set comes in response to issues identified while adding PoDL
PSE support to the stm32 prtt1c device tree. The existing pse-pd device
tree bindings did not allow node name patterns like "ethernet-pse-0" and
"ethernet-pse-1", leading to validation failures.

To address these false positives in validation, the device tree bindings
are extended to support these node name patterns. Alongside this, an
example node is added to aid in the improved validation process.
====================

Link: https://lore.kernel.org/r/20230531102113.3353065-1-o.rempel@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Extend the pattern matching for PSE-PD controller nodes to allow -N
suffixes. This enables the use of multiple "ethernet-pse" nodes without the
need for a "reg" property.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In the offending fixes commit I mistakenly removed the reply message of
the port new command. I was under impression it is a new port
notification, partly due to the "notify" in the name of the helper
function. Bring the code sending reply with new port message back, this
time putting it directly to devlink_nl_cmd_port_new_doit()

Fixes: c496daeb ("devlink: remove duplicate port notification")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230531142025.2605001-1-jiri@resnulli.usSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/sfc/tc.c
  622ab656 ("sfc: fix error unwinds in TC offload")
  b6583d5e ("sfc: support TC decap rules matching on enc_src_port")

net/mptcp/protocol.c
  5b825727 ("mptcp: add annotations around msk->subflow accesses")
  e76c8ef5 ("mptcp: refactor mptcp_stream_accept()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking fixes from Jakub Kicinski:
 "Happy Wear a Dress Day.

  Fairly standard-sized batch of fixes, accounting for the lack of
  sub-tree submissions this week. The mlx5 IRQ fixes are notable, people
  were complaining about that. No fires burning.

  Current release - regressions:

   - eth: mlx5e:
      - multiple fixes for dynamic IRQ allocation
      - prevent encap offload when neigh update is running

   - eth: mana: fix perf regression: remove rx_cqes, tx_cqes counters

  Current release - new code bugs:

   - eth: mlx5e: DR, add missing mutex init/destroy in pattern manager

  Previous releases - always broken:

   - tcp: deny tcp_disconnect() when threads are waiting

   - sched: prevent ingress Qdiscs from getting installed in random
     locations in the hierarchy and moving around

   - sched: flower: fix possible OOB write in fl_set_geneve_opt()

   - netlink: fix NETLINK_LIST_MEMBERSHIPS length report

   - udp6: fix race condition in udp6_sendmsg & connect

   - tcp: fix mishandling when the sack compression is deferred

   - rtnetlink: validate link attributes set at creation time

   - mptcp: fix connect timeout handling

   - eth: stmmac: fix call trace when stmmac_xdp_xmit() is invoked

   - eth: amd-xgbe: fix the false linkup in xgbe_phy_status

   - eth: mlx5e:
      - fix corner cases in internal buffer configuration
      - drain health before unregistering devlink

   - usb: qmi_wwan: set DTR quirk for BroadMobi BM818

  Misc:

   - tcp: return user_mss for TCP_MAXSEG in CLOSE/LISTEN state if
     user_mss set"

* tag 'net-6.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (71 commits)
  mptcp: fix active subflow finalization
  mptcp: add annotations around sk->sk_shutdown accesses
  mptcp: fix data race around msk->first access
  mptcp: consolidate passive msk socket initialization
  mptcp: add annotations around msk->subflow accesses
  mptcp: fix connect timeout handling
  rtnetlink: add the missing IFLA_GRO_ tb check in validate_linkmsg
  rtnetlink: move IFLA_GSO_ tb check to validate_linkmsg
  rtnetlink: call validate_linkmsg in rtnl_create_link
  ice: recycle/free all of the fragments from multi-buffer frame
  net: phy: mxl-gpy: extend interrupt fix to all impacted variants
  net: renesas: rswitch: Fix return value in error path of xmit
  net: dsa: mv88e6xxx: Increase wait after reset deactivation
  net: ipa: Use correct value for IPA_STATUS_SIZE
  tcp: fix mishandling when the sack compression is deferred.
  net/sched: flower: fix possible OOB write in fl_set_geneve_opt()
  sfc: fix error unwinds in TC offload
  net/mlx5: Read embedded cpu after init bit cleared
  net/mlx5e: Fix error handling in mlx5e_refresh_tirs
  net/mlx5: Ensure af_desc.mask is properly initialized
  ...

When switching from kthreads to vhost_tasks two bugs were added:
1. The vhost worker tasks's now show up as processes so scripts doing
ps or ps a would not incorrectly detect the vhost task as another
process.  2. kthreads disabled freeze by setting PF_NOFREEZE, but
vhost tasks's didn't disable or add support for them.

To fix both bugs, this switches the vhost task to be thread in the
process that does the VHOST_SET_OWNER ioctl, and has vhost_worker call
get_signal to support SIGKILL/SIGSTOP and freeze signals. Note that
SIGKILL/STOP support is required because CLONE_THREAD requires
CLONE_SIGHAND which requires those 2 signals to be supported.

This is a modified version of the patch written by Mike Christie
<michael.christie@oracle.com> which was a modified version of patch
originally written by Linus.

Much of what depended upon PF_IO_WORKER now depends on PF_USER_WORKER.
Including ignoring signals, setting up the register state, and having
get_signal return instead of calling do_group_exit.

Tidied up the vhost_task abstraction so that the definition of
vhost_task only needs to be visible inside of vhost_task.c.  Making
it easier to review the code and tell what needs to be done where.
As part of this the main loop has been moved from vhost_worker into
vhost_task_fn.  vhost_worker now returns true if work was done.

The main loop has been updated to call get_signal which handles
SIGSTOP, freezing, and collects the message that tells the thread to
exit as part of process exit.  This collection clears
__fatal_signal_pending.  This collection is not guaranteed to
clear signal_pending() so clear that explicitly so the schedule()
sleeps.

For now the vhost thread continues to exist and run work until the
last file descriptor is closed and the release function is called as
part of freeing struct file.  To avoid hangs in the coredump
rendezvous and when killing threads in a multi-threaded exec.  The
coredump code and de_thread have been modified to ignore vhost threads.

Remvoing the special case for exec appears to require teaching
vhost_dev_flush how to directly complete transactions in case
the vhost thread is no longer running.

Removing the special case for coredump rendezvous requires either the
above fix needed for exec or moving the coredump rendezvous into
get_signal.

Fixes: 6e890c5d ("vhost: use vhost_tasks for worker threads")
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Co-developed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Saeed Mahameed says:

====================
mlx5 fixes 2023-05-31

This series provides bug fixes to mlx5 driver.

* tag 'mlx5-fixes-2023-05-31' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
  net/mlx5: Read embedded cpu after init bit cleared
  net/mlx5e: Fix error handling in mlx5e_refresh_tirs
  net/mlx5: Ensure af_desc.mask is properly initialized
  net/mlx5: Fix setting of irq->map.index for static IRQ case
  net/mlx5: Remove rmap also in case dynamic MSIX not supported
====================

Link: https://lore.kernel.org/r/20230601031051.131529-1-saeed@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Mat Martineau says:

====================
mptcp: Fixes for connect timeout, access annotations, and subflow init

Patch 1 allows the SO_SNDTIMEO sockopt to correctly change the connect
timeout on MPTCP sockets.

Patches 2-5 add READ_ONCE()/WRITE_ONCE() annotations to fix KCSAN issues.

Patch 6 correctly initializes some subflow fields on outgoing connections.
====================

Link: https://lore.kernel.org/r/20230531-send-net-20230531-v1-0-47750c420571@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Active subflow are inserted into the connection list at creation time.
When the MPJ handshake completes successfully, a new subflow creation
netlink event is generated correctly, but the current code wrongly
avoid initializing a couple of subflow data.

The above will cause misbehavior on a few exceptional events: unneeded
mptcp-level retransmission on msk-level sequence wrap-around and infinite
mapping fallback even when a MPJ socket is present.

Address the issue factoring out the needed initialization in a new helper
and invoking the latter from __mptcp_finish_join() time for passive
subflow and from mptcp_finish_join() for active ones.

Fixes: 0530020a ("mptcp: track and update contiguous data status")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Christoph reported the mptcp variant of a recently addressed plain
TCP issue. Similar to commit e14cadfd ("tcp: add annotations around
sk->sk_shutdown accesses") add READ/WRITE ONCE annotations to silence
KCSAN reports around lockless sk_shutdown access.

Fixes: 71ba088c ("mptcp: cleanup accept and poll")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/401Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The first subflow socket is accessed outside the msk socket lock
by mptcp_subflow_fail(), we need to annotate each write access
with WRITE_ONCE, but a few spots still lacks it.

Fixes: 76a13b31 ("mptcp: invoke MP_FAIL response when needed")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When the msk socket is cloned at MPC handshake time, a few
fields are initialized in a racy way outside mptcp_sk_clone()
and the msk socket lock.

The above is due historical reasons: before commit a88d0092
("mptcp: simplify subflow_syn_recv_sock()") as the first subflow socket
carrying all the needed date was not available yet at msk creation
time

We can now refactor the code moving the missing initialization bit
under the socket lock, removing the init race and avoiding some
code duplication.

This will also simplify the next patch, as all msk->first write
access are now under the msk socket lock.

Fixes: 0397c6d8 ("mptcp: keep unaccepted MPC subflow into join list")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The MPTCP can access the first subflow socket in a few spots
outside the socket lock scope. That is actually safe, as MPTCP
will delete the socket itself only after the msk sock close().

Still the such accesses causes a few KCSAN splats, as reported
by Christoph. Silence the harmless warning adding a few annotation
around the relevant accesses.

Fixes: 71ba088c ("mptcp: cleanup accept and poll")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/402Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>