dev_get_stats() can be called from RCU, there is no need
to acquire dev_base_lock.

Change dev_isalive() comment to reflect we no longer use
dev_base_lock from net/core/net-sysfs.c
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

operstate_show() can omit dev_base_lock acquisition only
to read dev->operstate.

Annotate accesses to dev->operstate.

Writers still acquire dev_base_lock for mutual exclusion.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using dev_base_lock is not preventing from reading garbage.

Use dev_addr_sem instead.

v4: place dev_addr_sem extern in net/core/dev.h (Jakub Kicinski)
 Link: https://lore.kernel.org/netdev/20240212175845.10f6680a@kernel.org/Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make clear dev_isalive() can be called with RCU protection.

Then convert netdev_show() to RCU, to remove dev_base_lock
dependency.

Also add RCU to broadcast_show().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Prepares things so that dev->reg_state reads can be lockless,
by adding WRITE_ONCE() on write side.

READ_ONCE()/WRITE_ONCE() do not support bitfields.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Following patch will read dev->link locklessly,
annotate the write from do_setlink().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

t->parms.link is read locklessly, annotate these reads
and opposite writes accordingly.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

name_assign_type_show() runs locklessly, we should annotate
accesses to dev->name_assign_type.

Alternative would be to grab devnet_rename_sem semaphore
from name_assign_type_show(), but this would not bring
more accuracy.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Joe Damato says:

====================
Per epoll context busy poll support

Greetings:

Welcome to v8.

TL;DR This builds on commit bf3b9f63 ("epoll: Add busy poll support to
epoll with socket fds.") by allowing user applications to enable
epoll-based busy polling, set a busy poll packet budget, and enable or
disable prefer busy poll on a per epoll context basis.

This makes epoll-based busy polling much more usable for user
applications than the current system-wide sysctl and hardcoded budget.

To allow for this, two ioctls have been added for epoll contexts for
getting and setting a new struct, struct epoll_params.

ioctl was chosen vs a new syscall after reviewing a suggestion by Willem
de Bruijn [1]. I am open to using a new syscall instead of an ioctl, but it
seemed that:
  - Busy poll affects all existing epoll_wait and epoll_pwait variants in
    the same way, so new verions of many syscalls might be needed. It
    seems much simpler for users to use the correct
    epoll_wait/epoll_pwait for their app and add a call to ioctl to enable
    or disable busy poll as needed. This also probably means less work to
    get an existing epoll app using busy poll.

  - previously added epoll_pwait2 helped to bring epoll closer to
    existing syscalls (like pselect and ppoll) and this busy poll change
    reflected as a new syscall would not have the same effect.

Note: patch 1/4 as of v4 uses an or (||) instead of an xor. I thought about
it some more and I realized that if the user enables both the per-epoll
context setting and the system wide sysctl, then busy poll should be
enabled and not disabled. Using xor doesn't seem to make much sense after
thinking through this a bit.

Longer explanation:

Presently epoll has support for a very useful form of busy poll based on
the incoming NAPI ID (see also: SO_INCOMING_NAPI_ID [2]).

This form of busy poll allows epoll_wait to drive NAPI packet processing
which allows for a few interesting user application designs which can
reduce latency and also potentially improve L2/L3 cache hit rates by
deferring NAPI until userland has finished its work.

The documentation available on this is, IMHO, a bit confusing so please
allow me to explain how one might use this:

1. Ensure each application thread has its own epoll instance mapping
1-to-1 with NIC RX queues. An n-tuple filter would likely be used to
direct connections with specific dest ports to these queues.

2. Optionally: Setup IRQ coalescing for the NIC RX queues where busy
polling will occur. This can help avoid the userland app from being
pre-empted by a hard IRQ while userland is running. Note this means that
userland must take care to call epoll_wait and not take too long in
userland since it now drives NAPI via epoll_wait.

3. Optionally: Consider using napi_defer_hard_irqs and gro_flush_timeout to
further restrict IRQ generation from the NIC. These settings are
system-wide so their impact must be carefully weighed against the running
applications.

4. Ensure that all incoming connections added to an epoll instance
have the same NAPI ID. This can be done with a BPF filter when
SO_REUSEPORT is used or getsockopt + SO_INCOMING_NAPI_ID when a single
accept thread is used which dispatches incoming connections to threads.

5. Lastly, busy poll must be enabled via a sysctl
(/proc/sys/net/core/busy_poll).

Please see Eric Dumazet's paper about busy polling [3] and a recent
academic paper about measured performance improvements of busy polling [4]
(albeit with a modification that is not currently present in the kernel)
for additional context.

The unfortunate part about step 5 above is that this enables busy poll
system-wide which affects all user applications on the system,
including epoll-based network applications which were not intended to
be used this way or applications where increased CPU usage for lower
latency network processing is unnecessary or not desirable.

If the user wants to run one low latency epoll-based server application
with epoll-based busy poll, but would like to run the rest of the
applications on the system (which may also use epoll) without busy poll,
this system-wide sysctl presents a significant problem.

This change preserves the system-wide sysctl, but adds a mechanism (via
ioctl) to enable or disable busy poll for epoll contexts as needed by
individual applications, making epoll-based busy poll more usable.

Note that this change includes an or (as of v4) instead of an xor. If the
user has enabled both the system-wide sysctl and also the per epoll-context
busy poll settings, then epoll should probably busy poll (vs being
disabled).

Thanks,
Joe

v7 -> v8:
   - Reviewed-by tag from Eric Dumazet applied to commit message of patch
     1/4.

   - patch 4/4:
     - EPIOCSPARAMS and EPIOCGPARAMS updated to use WRITE_ONCE and
       READ_ONCE, as requested by Eric Dumazet
     - Wrapped a long line (via netdev/checkpatch)

v6 -> v7:
   - Acked-by tags from Stanislav Fomichev applied to commit messages of
     all patches.
   - Reviewed-by tags from Jakub Kicinski, Eric Dumazet applied to commit
     messages of patches 2 and 3. Jiri Slaby's Reviewed-by applied to patch
     4.

   - patch 1/4:
     - busy_poll_usecs reduced from u64 to u32.
     - Unnecessary parens removed (via netdev/checkpatch)
     - Wrapped long line (via netdev/checkpatch)
     - Remove inline from busy_loop_ep_timeout as objdump suggests the
       function is already inlined
     - Moved struct eventpoll assignment to declaration
     - busy_loop_ep_timeout is moved within CONFIG_NET_RX_BUSY_POLL and the
       ifdefs internally have been removed as per Eric Dumazet's review
     - Removed ep_busy_loop_on from the !defined CONFIG_NET_RX_BUSY_POLL
       section as it is only called when CONFIG_NET_RX_BUSY_POLL is
       defined

   - patch 3/4:
     - Fix whitespace alignment issue (via netdev/checkpatch)

   - patch 4/4:
     - epoll_params.busy_poll_usecs has been reduced to u32
     - epoll_params.busy_poll_usecs is now checked to ensure it is <=
       S32_MAX
     - __pad has been reduced to a single u8
     - memchr_inv has been dropped and replaced with a simple check for the
       single __pad byte
     - Removed space after cast (via netdev/checkpatch)
     - Wrap long line (via netdev/checkpatch)
     - Move struct eventpoll *ep assignment to declaration as per Jiri
       Slaby's review
     - Remove unnecessary !! as per Jiri Slaby's review
     - Reorganized variables to be reverse christmas tree order

v5 -> v6:
  - patch 1/3 no functional change, but commit message corrected to explain
    that an or (||) is being used instead of xor.

  - patch 3/4 is a new patch which adds support for per epoll context
    prefer busy poll setting.

  - patch 4/4 updated to allow getting/setting per epoll context prefer
    busy poll setting; this setting is limited to either 0 or 1.

v4 -> v5:
  - patch 3/3 updated to use memchr_inv to ensure that __pad is zero for
    the EPIOCSPARAMS ioctl. Recommended by Greg K-H [5], Dave Chinner [6],
    and Jiri Slaby [7].

v3 -> v4:
  - patch 1/3 was updated to include an important functional change:
    ep_busy_loop_on was updated to use or (||) instead of xor (^). After
    thinking about it a bit more, I thought xor didn't make much sense.
    Enabling both the per-epoll context and the system-wide sysctl should
    probably enable busy poll, not disable it. So, or (||) makes more
    sense, I think.

  - patch 3/3 was updated:
    - to change the epoll_params fields to be __u64, __u16, and __u8 and
      to pad the struct to a multiple of 64bits. Suggested by Greg K-H [8]
      and Arnd Bergmann [9].
    - remove an unused pr_fmt, left over from the previous revision.
    - ioctl now returns -EINVAL when epoll_params.busy_poll_usecs >
      U32_MAX.

v2 -> v3:
  - cover letter updated to mention why ioctl seems (to me) like a better
    choice vs a new syscall.

  - patch 3/4 was modified in 3 ways:
    - when an unknown ioctl is received, -ENOIOCTLCMD is returned instead
      of -EINVAL as the ioctl documentation requires.
    - epoll_params.busy_poll_budget can only be set to a value larger than
      NAPI_POLL_WEIGHT if code is run by privileged (CAP_NET_ADMIN) users.
      Otherwise, -EPERM is returned.
    - busy poll specific ioctl code moved out to its own function. On
      kernels without busy poll support, -EOPNOTSUPP is returned. This also
      makes the kernel build robot happier without littering the code with
      more #ifdefs.

  - dropped patch 4/4 after Eric Dumazet's review of it when it was sent
    independently to the list [10].

v1 -> v2:
  - cover letter updated to make a mention of napi_defer_hard_irqs and
    gro_flush_timeout as an added step 3 and to cite both Eric Dumazet's
    busy polling paper and a paper from University of Waterloo for
    additional context. Specifically calling out the xor in patch 1/4
    incase it is missed by reviewers.

  - Patch 2/4 has its commit message updated, but no functional changes.
    Commit message now describes that allowing for a settable budget helps
    to improve throughput and is more consistent with other busy poll
    mechanisms that allow a settable budget via SO_BUSY_POLL_BUDGET.

  - Patch 3/4 was modified to check if the epoll_params.busy_poll_budget
    exceeds NAPI_POLL_WEIGHT. The larger value is allowed, but an error is
    printed. This was done for consistency with netif_napi_add_weight,
    which does the same.

  - Patch 3/4 the struct epoll_params was updated to fix the type of the
    data field; it was uint8_t and was changed to u8.

  - Patch 4/4 added to check if SO_BUSY_POLL_BUDGET exceeds
    NAPI_POLL_WEIGHT. The larger value is allowed, but an error is
    printed. This was done for consistency with netif_napi_add_weight,
    which does the same.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add an ioctl for getting and setting epoll_params. User programs can use
this ioctl to get and set the busy poll usec time, packet budget, and
prefer busy poll params for a specific epoll context.

Parameters are limited:
  - busy_poll_usecs is limited to <= s32_max
  - busy_poll_budget is limited to <= NAPI_POLL_WEIGHT by unprivileged
    users (!capable(CAP_NET_ADMIN))
  - prefer_busy_poll must be 0 or 1
  - __pad must be 0
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When using epoll-based busy poll, the prefer_busy_poll option is hardcoded
to false. Users may want to enable prefer_busy_poll to be used in
conjunction with gro_flush_timeout and defer_hard_irqs_count to keep device
IRQs masked.

Other busy poll methods allow enabling or disabling prefer busy poll via
SO_PREFER_BUSY_POLL, but epoll-based busy polling uses a hardcoded value.

Fix this edge case by adding support for a per-epoll context
prefer_busy_poll option. The default is false, as it was hardcoded before
this change.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When using epoll-based busy poll, the packet budget is hardcoded to
BUSY_POLL_BUDGET (8). Users may desire larger busy poll budgets, which
can potentially increase throughput when busy polling under high network
load.

Other busy poll methods allow setting the busy poll budget via
SO_BUSY_POLL_BUDGET, but epoll-based busy polling uses a hardcoded
value.

Fix this edge case by adding support for a per-epoll context busy poll
packet budget. If not specified, the default value (BUSY_POLL_BUDGET) is
used.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow busy polling on a per-epoll context basis. The per-epoll context
usec timeout value is preferred, but the pre-existing system wide sysctl
value is still supported if it specified.

busy_poll_usecs is a u32, but in a follow up patch the ioctl provided to
the user only allows setting a value from 0 to S32_MAX.
Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is no point in initializing an ndo to NULL, therefore the
assignment is redundant and can be removed.
Signed-off-by: Kamal Heib <kheib@redhat.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Acked-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Packet ingress and egress MAC/serdes channel numbers are configurable
on CN10K series of silicons. These channel numbers inturn used while
installing MCAM rules to match ingress/egress port. Fetch these channel
numbers from firmware at driver init time.
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tony Nguyen says:

====================
Intel Wired LAN Driver Updates 2024-02-12 (ice)

This series contains updates to ice driver only.

Grzegorz adds support for E825-C devices.

Wojciech reworks devlink reload to fulfill expected conditions (remove
and readd).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'linux-can-next-for-6.9-20240213' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
linux-can-next-for-6.9-20240213

this is a pull request of 23 patches for net-next/master.

The first patch is by Nicolas Maier and targets the CAN Broadcast
Manager (bcm), it adds message flags to distinguish between own local
and remote traffic.

Oliver Hartkopp contributes a patch for the CAN ISOTP protocol that
adds dynamic flow control parameters.

Stefan Mätje's patch series add support for the esd PCIe/402 CAN
interface family.

Markus Schneider-Pargmann contributes 14 patches for the m_can to
optimize for the SPI attached tcan4x5x controller.

A patch by Vincent Mailhol replaces Wolfgang Grandegger by Vincent
Mailhol as the CAN drivers Co-Maintainer.

Jimmy Assarsson's patch add support for the Kvaser M.2 PCIe 4xCAN
adapter.

A patch by Daniil Dulov removed a redundant NULL check in the softing
driver.

Oliver Hartkopp contributes a patch to add CANXL virtual CAN network
identifier support.

A patch by myself removes Naga Sureshkumar Relli as the maintainer of
the xilinx_can driver, as their email bounces.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Lorenzo Bianconi says:

====================
add multi-buff support for xdp running in generic mode

Introduce multi-buffer support for xdp running in generic mode not always
linearizing the skb in netif_receive_generic_xdp routine.
Introduce generic percpu page_pools allocator.
====================

Link: https://lore.kernel.org/r/cover.1707729884.git.lorenzo@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Rely on skb_pp_cow_data utility routine and remove duplicated code.
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/029cc14cce41cb242ee7efdcf32acc81f1ce4e9f.1707729884.git.lorenzo@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Similar to native xdp, do not always linearize the skb in
netif_receive_generic_xdp routine but create a non-linear xdp_buff to be
processed by the eBPF program. This allow to add multi-buffer support
for xdp running in generic mode.
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/1044d6412b1c3e95b40d34993fd5f37cd2f319fd.1707729884.git.lorenzo@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Rely on skb pointer reference instead of the skb pointer in do_xdp_generic
and netif_receive_generic_xdp routine signatures.
This is a preliminary patch to add multi-buff support for xdp running in
generic mode where we will need to reallocate the skb to avoid
linearization and we will need to make it visible to do_xdp_generic()
caller.
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/c09415b1f48c8620ef4d76deed35050a7bddf7c2.1707729884.git.lorenzo@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Introduce generic percpu page_pools allocator.
Moreover add page_pool_create_percpu() and cpuid filed in page_pool struct
in order to recycle the page in the page_pool "hot" cache if
napi_pp_put_page() is running on the same cpu.
This is a preliminary patch to add xdp multi-buff support for xdp running
in generic mode.
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/80bc4285228b6f4220cd03de1999d86e46e3fcbd.1707729884.git.lorenzo@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

While no supported devices currently utilize EXT0, the register reserves
the bits for an EXT0. EXT0 is utilized by devices from the generation
prior to rtl8365mb, such as those supported by the driver library
rtl8367b.
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240212-realtek-fix_ext0-v1-1-f3d2536d191a@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Heiner Kallweit says:

====================
r8169: extend EEE tx idle timer support

This series extends EEE tx idle timer support, and exposes the timer
value to userspace.
====================

Link: https://lore.kernel.org/r/89a5fef5-a4b7-4d5d-9c35-764248be5a19@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add support for returning the tx_lpi_timer value to userspace.
This is supported by few chip versions only: RTL8168h/RTL8125/RTL8126
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/4eee9c34-c5d6-4c96-9b05-455896dea59a@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Support setting the EEE tx idle timer also on RTL8168h.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/cfb69ec9-24c4-4aad-9909-fdae3088add4@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add a generic setter for the EEE tx idle timer and use it with all
RTL8125/RTL8126 chip versions, in line with the vendor driver.
This prepares for adding EEE tx idle timer support for additional
chip versions.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/39beed72-0dc4-4c45-8899-b72c43ab62a7@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This adds LED support for RTL8125/RTL8126.

Note: Due to missing datasheets changing the 5Gbps link mode isn't
supported for RTL8126.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/f982602c-9de3-4ca6-85a3-2c1d118dcb15@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Convert the Qualcomm Atheros AR9331 built-in switch bindings to DT
schema.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20240212182911.233819-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

FEC_ENET_FCE is the Flow Control Enable bit (bit 5) of the RCR.
This is now defined as FEC_RCR_FLOWCTL.
Signed-off-by: Csókás Bence <csokas.bence@prolan.hu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240212153717.10023-2-csokas.bence@prolan.huSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add defines for bits of ECR, RCR control registers, TX watermark etc.
Signed-off-by: Csókás Bence <csokas.bence@prolan.hu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240212153717.10023-1-csokas.bence@prolan.huSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Eric Dumazet says:

====================
net: adopt netdev_lockdep_set_classes()

Instead of waiting for syzbot to discover lockdep false positives,
make sure we use netdev_lockdep_set_classes() a bit more.
====================

Link: https://lore.kernel.org/r/20240212140700.2795436-1-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Based on a syzbot report, it appears many virtual
drivers do not yet use netdev_lockdep_set_classes(),
triggerring lockdep false positives.

WARNING: possible recursive locking detected
6.8.0-rc4-next-20240212-syzkaller #0 Not tainted

syz-executor.0/19016 is trying to acquire lock:
 ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline]
 ffff8880162cb298 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340

but task is already holding lock:
 ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline]
 ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
  lock(_xmit_ETHER#2);
  lock(_xmit_ETHER#2);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

9 locks held by syz-executor.0/19016:
  #0: ffffffff8f385208 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
  #0: ffffffff8f385208 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6603
  #1: ffffc90000a08c00 ((&in_dev->mr_ifc_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1697
  #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
  #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
  #2: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1360 net/ipv4/ip_output.c:228
  #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
  #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
  #3: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4284
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline]
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:195 [inline]
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3771 [inline]
  #4: ffff8880416e3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3b10 net/core/dev.c:4325
  #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
  #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4452 [inline]
  #5: ffff8880223db4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340
  #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
  #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
  #6: ffffffff8e131520 (rcu_read_lock){....}-{1:2}, at: ip_finish_output2+0x45f/0x1360 net/ipv4/ip_output.c:228
  #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
  #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline]
  #7: ffffffff8e131580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4284
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:361 [inline]
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:195 [inline]
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3771 [inline]
  #8: ffff888014d9d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3b10 net/core/dev.c:4325

stack backtrace:
CPU: 1 PID: 19016 Comm: syz-executor.0 Not tainted 6.8.0-rc4-next-20240212-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <IRQ>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
  check_deadlock kernel/locking/lockdep.c:3062 [inline]
  validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
  __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
  lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
  __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
  _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:351 [inline]
  __netif_tx_lock include/linux/netdevice.h:4452 [inline]
  sch_direct_xmit+0x1c4/0x5f0 net/sched/sch_generic.c:340
  __dev_xmit_skb net/core/dev.c:3784 [inline]
  __dev_queue_xmit+0x1912/0x3b10 net/core/dev.c:4325
  neigh_output include/net/neighbour.h:542 [inline]
  ip_finish_output2+0xe66/0x1360 net/ipv4/ip_output.c:235
  iptunnel_xmit+0x540/0x9b0 net/ipv4/ip_tunnel_core.c:82
  ip_tunnel_xmit+0x20ee/0x2960 net/ipv4/ip_tunnel.c:831
  erspan_xmit+0x9de/0x1460 net/ipv4/ip_gre.c:720
  __netdev_start_xmit include/linux/netdevice.h:4989 [inline]
  netdev_start_xmit include/linux/netdevice.h:5003 [inline]
  xmit_one net/core/dev.c:3555 [inline]
  dev_hard_start_xmit+0x242/0x770 net/core/dev.c:3571
  sch_direct_xmit+0x2b6/0x5f0 net/sched/sch_generic.c:342
  __dev_xmit_skb net/core/dev.c:3784 [inline]
  __dev_queue_xmit+0x1912/0x3b10 net/core/dev.c:4325
  neigh_output include/net/neighbour.h:542 [inline]
  ip_finish_output2+0xe66/0x1360 net/ipv4/ip_output.c:235
  igmpv3_send_cr net/ipv4/igmp.c:723 [inline]
  igmp_ifc_timer_expire+0xb71/0xd90 net/ipv4/igmp.c:813
  call_timer_fn+0x17e/0x600 kernel/time/timer.c:1700
  expire_timers kernel/time/timer.c:1751 [inline]
  __run_timers+0x621/0x830 kernel/time/timer.c:2038
  run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2051
  __do_softirq+0x2bc/0x943 kernel/softirq.c:554
  invoke_softirq kernel/softirq.c:428 [inline]
  __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
  irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1076 [inline]
  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1076
 </IRQ>
 <TASK>
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 RIP: 0010:resched_offsets_ok kernel/sched/core.c:10127 [inline]
 RIP: 0010:__might_resched+0x16f/0x780 kernel/sched/core.c:10142
Code: 00 4c 89 e8 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df 48 89 44 24 38 0f b6 04 10 84 c0 0f 85 87 04 00 00 41 8b 45 00 c1 e0 08 <01> d8 44 39 e0 0f 85 d6 00 00 00 44 89 64 24 1c 48 8d bc 24 a0 00
RSP: 0018:ffffc9000ee069e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8880296a9e00
RDX: dffffc0000000000 RSI: ffff8880296a9e00 RDI: ffffffff8bfe8fa0
RBP: ffffc9000ee06b00 R08: ffffffff82326877 R09: 1ffff11002b5ad1b
R10: dffffc0000000000 R11: ffffed1002b5ad1c R12: 0000000000000000
R13: ffff8880296aa23c R14: 000000000000062a R15: 1ffff92001dc0d44
  down_write+0x19/0x50 kernel/locking/rwsem.c:1578
  kernfs_activate fs/kernfs/dir.c:1403 [inline]
  kernfs_add_one+0x4af/0x8b0 fs/kernfs/dir.c:819
  __kernfs_create_file+0x22e/0x2e0 fs/kernfs/file.c:1056
  sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:307
  create_files fs/sysfs/group.c:64 [inline]
  internal_create_group+0x4f4/0xf20 fs/sysfs/group.c:152
  internal_create_groups fs/sysfs/group.c:192 [inline]
  sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:218
  create_dir lib/kobject.c:78 [inline]
  kobject_add_internal+0x472/0x8d0 lib/kobject.c:240
  kobject_add_varg lib/kobject.c:374 [inline]
  kobject_init_and_add+0x124/0x190 lib/kobject.c:457
  netdev_queue_add_kobject net/core/net-sysfs.c:1706 [inline]
  netdev_queue_update_kobjects+0x1f3/0x480 net/core/net-sysfs.c:1758
  register_queue_kobjects net/core/net-sysfs.c:1819 [inline]
  netdev_register_kobject+0x265/0x310 net/core/net-sysfs.c:2059
  register_netdevice+0x1191/0x19c0 net/core/dev.c:10298
  bond_newlink+0x3b/0x90 drivers/net/bonding/bond_netlink.c:576
  rtnl_newlink_create net/core/rtnetlink.c:3506 [inline]
  __rtnl_newlink net/core/rtnetlink.c:3726 [inline]
  rtnl_newlink+0x158f/0x20a0 net/core/rtnetlink.c:3739
  rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6606
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
  netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367
  netlink_sendmsg+0xa3c/0xd70 net/netlink/af_netlink.c:1908
  sock_sendmsg_nosec net/socket.c:730 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:745
  __sys_sendto+0x3a4/0x4f0 net/socket.c:2191
  __do_sys_sendto net/socket.c:2203 [inline]
  __se_sys_sendto net/socket.c:2199 [inline]
  __x64_sys_sendto+0xde/0x100 net/socket.c:2199
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc3fa87fa9c
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240212140700.2795436-4-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

br_set_lockdep_class() is missing many details.
Use generic netdev_lockdep_set_classes() to not worry anymore.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240212140700.2795436-3-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

vlan uses vlan_dev_set_lockdep_class() which lacks qdisc_tx_busylock
initialization.

Use generic netdev_lockdep_set_classes() to not worry anymore.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240212140700.2795436-2-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Eric Dumazet says:

====================
net: use net->dev_by_index in two places

Bring "ip link" ordering to /proc/net/dev one (by ifindexes).

Do the same for /proc/net/vlan/config

v2: https://lore.kernel.org/all/20240209142441.6c56435b@kernel.org/
====================

Link: https://lore.kernel.org/r/20240211214404.1882191-1-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Adopt net->dev_by_index as I did in commit 0e0939c0
("net-procfs: use xarray iterator to implement /proc/net/dev")

This makes sure an existing device is always visible in the dump,
regardless of concurrent insertions/deletions.

v2: added suggestions from Jakub Kicinski and Ido Schimmel,
    thanks for the help !

Link: https://lore.kernel.org/all/20240209142441.6c56435b@kernel.org/
Link: https://lore.kernel.org/all/ZckR-XOsULLI9EHc@shredder/Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20240211214404.1882191-3-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Adopt net->dev_by_index as I did in commit 0e0939c0
("net-procfs: use xarray iterator to implement /proc/net/dev")

Not only this removes quadratic behavior, it also makes sure
an existing vlan device is always visible in the dump,
regardless of concurrent net->dev_base_head changes.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20240211214404.1882191-2-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

PMD Global Transmit Disable bit should be cleared for normal operation.
This should be HW default, however I found that on Asus RT-AX89X that uses
AQR113C PHY and firmware 5.4 this bit is set by default.

With this bit set the AQR cannot achieve a link with its link-partner and
it took me multiple hours of digging through the vendor GPL source to find
this out, so lets always clear this bit during .config_init() to avoid a
situation like this in the future.
Signed-off-by: Robert Marko <robimarko@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240211181732.646311-1-robimarko@gmail.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

The prologue to codel is using BSD-3 clause and GPL-2 boiler plate
language. Replace it by using SPDX. The automated treewide scan in
commit d2912cb1 ("treewide: Replace GPLv2 boilerplate/reference with
SPDX - rule 500") did not pickup dual licensed code.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Dave Taht <dave.taht@gmail.com>
Link: https://lore.kernel.org/r/20240211172532.6568-1-stephen@networkplumber.orgSigned-off-by: Paolo Abeni <pabeni@redhat.com>