ETHTOOL_A_RSS_HFUNC and ETHTOOL_A_RSS_INPUT_XFRM are NLA_U32 attributes,
but ethnl_rss_set() and ethnl_rss_create_doit() parse them with
ethnl_update_u8(), which reads a single byte.
On little endian this happens to read the least significant byte and
works as long as the value fits in a byte. On big endian it reads the
most significant byte, so the requested value is parsed incorrectly.
The destination fields in struct ethtool_rxfh_param are u8, so the
attribute can't be read directly with ethnl_update_u32().
Cap the hfunc policy at U8_MAX so an out of range value is rejected
instead of being silently truncated into the u8 field, and add
ethnl_update_u8_u32() to read the full u32 and narrow it into the u8
destination.
Fixes: 82ae67cbc4 ("ethtool: rss: support setting hfunc via Netlink")
Fixes: d3e2c7bab1 ("ethtool: rss: support setting input-xfrm via Netlink")
Fixes: a166ab7816 ("ethtool: rss: support creating contexts via Netlink")
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20260706055017.3355806-1-gal@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Breno reports following splats on mlx5:
RTNL: assertion failed at net/core/dev.c (2241)
WARNING: net/core/dev.c:2241 at netif_state_change+0xed/0x130, CPU#5: ethtool/1335
RIP: 0010:netif_state_change+0xf9/0x130
Call Trace:
<TASK>
__linkwatch_sync_dev+0xea/0x120
ethtool_op_get_link+0xe/0x20
__ethtool_get_link+0x26/0x40
linkstate_prepare_data+0x51/0x200
ethnl_default_doit+0x213/0x470
genl_family_rcv_msg_doit+0xdd/0x110
Looks like I missed ethtool_op_get_link() trying to sync linkwatch,
which needs rtnl_lock. Not all drivers do this - bnxt doesn't,
it just returns the link state, so add an opt-in bit.
Reported-by: Breno Leitao <leitao@debian.org>
Fixes: 45079e0013 ("net: ethtool: optionally skip rtnl_lock on Netlink path for GET ops")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Breno Leitao <leitao@debian.org>
Acked-by: Harshitha Ramamurthy <hramamurthy@google.com>
Link: https://patch.msgid.link/20260624190439.2521219-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mlx5 throws ASSERT_RTNL() warnings on timestamp config, because
it tries to update features. mlx5e_hwtstamp_set() calls
netdev_update_features().
I missed this while grepping the drivers because tsconfig goes
through ndo_hwtstamp_set/get, not ethtool ops, even tho the new
uAPI is in ethtool Netlink. We could add a dedicated opt out bit
for mlx5, but NDOs were not supposed to be part of the ethtool locking
conversion in the first place.
The mlx5 features update is related to the "compressed CQE" format
which lacks timestamp, apparently. See commit c0194e2d0e ("net/mlx5e:
Disable rxhash when CQE compress is enabled").
Fixes: f9a3e05114 ("net: ethtool: optionally skip rtnl_lock on Netlink path for SET ops")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20260611200355.2020663-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce vendor-specific PHY tunable identifiers to control the
KSZ87xx low-loss cable erratum handling through the ethtool PHY
tunable interface.
The following tunables are added:
- a boolean "short-cable" tunable, applying a documented and
conservative preset intended for short or low-loss Ethernet cables;
- an integer LPF bandwidth tunable, allowing advanced adjustment of the
receiver low-pass filter bandwidth;
- an integer DSP EQ initial value tunable, allowing advanced tuning of
the PHY equalizer initialization.
The actual behavior is implemented by the corresponding PHY and switch
drivers.
Reviewed-by: Marek Vasut <marex@nabladev.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Signed-off-by: Fidelio Lawson <fidelio.lawson@exotec.com>
Link: https://patch.msgid.link/20260609-ksz87xx_errata_low_loss_connections-v10-2-9ba4418cf3db@exotec.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Convert the IOCTL path similarly to how we converted Netlink.
The device lookup gets a little hairy. We could take rtnl_lock
unconditionally and drop it before calling the driver (this would
avoid the reference + liveness check). But I think being able
to make progress even if rtnl is dead-locked is quite useful.
First extra concern is handling features. List all the cmds which
modify features and always take rtnl_lock. We could fold this list
into ethtool_ioctl_needs_rtnl() but seems cleaner to keep
ethtool_ioctl_needs_rtnl() driver-related. If a driver changed
features and we were not holding rtnl_lock - warn about it.
It can only happen on buggy ops locked drivers (buggy because
they should have set appropriate "I need rtnl for op X" bit).
Second wrinkle is the PHY ID hack which drops the locks while
sleeping. Convert its static "busy" variable which used to
be protected by rtnl_lock to a field in struct ethtool_netdev_state.
This feature is about identifying an adapter or a port within
a system, so being able to blink multiple LEDs at the same
time is likely not very useful in practice. But it's the simplest
fix, we can add a mutex if someone thinks a system should only
be ID'ing one port at a time.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-12-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Skip rtnl_lock in RSS context handlers if device is ops-locked.
Fairly trivial conversion. bnxt needed rtnl_lock for changing
the main context but looks like additional contexts are fine
without it.
Note (for review bots?) that ethnl_ops_begin() checks whether
the device is still registered.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Make ethtool not take rtnl_lock for SET commands when operation
is performed on an ops-locked driver. cfg/cfg_pending are now
ops-locked, since only ethtool modifies them.
Some SET driver callbacks will still need rtnl_lock, most notably
those which may end up calling netdev_update_features() or the qdisc
layer (via netif_set_real_num_tx_queues()). Let drivers selectively
opt back into the rtnl_lock with a new bitfield in ops.
We need two helpers since Netlink and ioctl cmds have different
values. Keep the helpers side by side in common.h to make sure
they get updated together, even tho they will only get called
from ioctl.c and netlink.c.
SET commands which don't use ethnl_default_set_doit() are converted
by subsequent commits.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ethnl_default_doit() and ethnl_default_dump_one() are both used
exclusively for GET callbacks (former to get info for a single
device or get global strings). ops-locked devices don't need
rtnl_lock for GET callbacks, stop taking it.
Introduce an opt-out mechanism for devices which use phylink (fbnic)
since phylink currently depends on rtnl_lock protection. Subsequent
patches will add more exceptions, anyway. Practically the new helpers
for judging if command needs rtnl_lock could also call
netdev_need_ops_lock() but I find that it makes the code in the callers
slightly less obvious.
Add a helper for IOCTLs already, even tho it's unused so that
we can keep them in sync as the series progresses.
This is the first user-visible step of moving ethtool ops out
from under rtnl. Subsequent patches do the same for SET ops,
as well as the ioctl path.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dev->hwprov tracks the active hwtstamp provider for the device.
Make it ops protected (instance lock if the netdev driver opts
into holding instance lock around callbacks, otherwise rtnl_lock).
hwprov is written and read in:
- drivers/net/phy/phy_device.c
phydev and ops protection don't currently mix, add a comment
- net/ethtool/
as of now holds both rtnl lock and ops lock, this one will
soon only hold one lock or the other
read in:
- net/core/dev_ioctl.c
holds both rtnl lock and ops lock
- net/core/timestamping.c
RCU reader
The new netdev_ops_lock_dereference() helper does not have
"compat" in the name. The name would be quite long and I think
in this case it should be obvious that we need _a_ lock.
netdev_lock_dereference() already exists and means dev->lock
is always expected.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
phydev <> netdev linking and lifecycle depends on rtnl_lock.
We want to switch to instance locks for most ethtool ops.
Let's add an assert that ops locked devices don't use phydev
today. If one does we can either opt the phy ops out of
being purely ops locked, or do deeper surgery to make phy
locking ops-compatible. I don't think there's any fundamental
challenge to make that work.
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ethnl_bcast_seq is a global counter stamped into the nlmsg_seq field
of every multicast notification, allowing userspace to detect dropped
messages. Today the ordering is achieved by using rtnl_lock().
Moving forward we will want ethtool ops to run under just the netdev
instance lock so to establish ordering we need a separate lock
for notifications. With the netdev instance locks operations on
different devices may bypass each other but the expectation is
that it should not matter. What we need to prevent is:
- notification IDs getting out of order
- operations on one device getting out of order
For simplicity defer allocating the ID of the notification right
before the notification is delivered. This removes the need for
special handling in ethnl_rss_create_send_ntf().
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20260605002912.3456868-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All drivers which may call *_get_link_ksettings() on ops-locked
devices from paths already holding the ops lock are ready now.
Make __ethtool_get_link_ksettings() take the ops lock, and assert
that it's held in netif_get_link_ksettings().
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-12-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
__ethtool_get_link_ksettings() is exported and called from sysfs
and many drivers. It invokes ethtool_ops->get_link_ksettings
so by our own docs it should be holding netdev lock for ops locked
devices. Looks like commit 2bcf4772e4 ("net: ethtool:
try to protect all callback with netdev instance lock")
missed adding the ops lock here.
There's a number of callers we need to fix up so let's add the
netif_get_link_ksettings() helper first, without any actual
locking changes (this commit is a nop).
Not treating this as a fix because I don't think any driver cares
at this point, but if we want to remove the rtnl_lock protection
this will become critical.
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
FW module flashing was written so that the flashing happens
without holding rtnl_lock. This allows flashing multiple modules
at once. Current drivers can handle that well, but we should
let drivers depend on the netdev instance lock. Instance lock
is per netdev, and so is the module so we won't break parallel
updates.
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jakub suggests renaming the existing assert to match
the netdev_lock_ops_compat() semantics.
We want netdev_assert_locked_ops() to mean - if the driver
is ops locked - check that it's holding the device lock.
The existing helper check for either ops lock or rtnl_lock,
which is the locking behavior of netdev_lock_ops_compat().
The reason for naming divergence is likely that
netdev_ops_assert_locked() predated the _compat() helpers.
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260603012840.2254293-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ETHTOOL_MSG_STRSET_GET is the only op which sets allow_nodev_do.
When no device is provided it dumps static tables, there's no
need to hold rtnl_lock for this.
Not taking rtnl_lock is a minor win in itself so I think this
patch stands on its own merits. Later on it will be useful
to do locking only in paths which have access to a netdev,
so that we can decide which locks to take per-netdev.
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260527162522.3344231-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The Netlink fallback path for reading module EEPROM
(fallback_set_params()) validates that offset < eeprom_len,
but does not check that offset + length stays within eeprom_len.
The ioctl equivalent (ethtool_get_any_eeprom() in ioctl.c) has
always enforced both bounds:
if (eeprom.offset + eeprom.len > total_len)
return -EINVAL;
This could lead to surprises in both drivers and device FW.
Add the missing offset + length validation to fallback_set_params(),
mirroring the ioctl.
Similarly - ethtool core in general, and ethtool_get_any_eeprom()
in particular tries to zero-init all buffers passed to the drivers
to avoid any extra work of zeroing things out. eeprom_fallback()
uses a plain kmalloc(), change it to zalloc.
Fixes: 96d971e307 ("ethtool: Add fallback to get_module_eeprom from netlink command")
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260526153533.2779187-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All ethtool driver op calls should be sandwiched between
ethnl_ops_begin() / ethnl_ops_complete(). In Netlink eeprom code,
if the paged access failed we fall back to old API, but we
first call _complete() and the fallback never does its own
ethnl_ops_begin(). Move the fallback into the _begin() / _complete()
section.
Fixes: 96d971e307 ("ethtool: Add fallback to get_module_eeprom from netlink command")
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260526153533.2779187-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
strset_prepare_data() passes ETHTOOL_A_HEADER_FLAGS (3) as the header
attribute to ethnl_req_get_phydev(). This is incorrect, in the main
attr space 3 is ETHTOOL_A_STRSET_COUNTS_ONLY, not the request
header attr. The correct constant is ETHTOOL_A_STRSET_HEADER (1).
ethnl_req_get_phydev() only uses this value for the extack,
so this is not a "functionally visible"(?) bug.
Fixes: e96c93aa4b ("net: ethtool: strset: Allow querying phy stats by index")
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260526153533.2779187-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Gal PressmanandPaolo Abeni
Jakub Kicinski
Sabrina DubrocaandJakub Kicinski
Fidelio LawsonandJakub Kicinski