We have to make sure that all future NAPIs will have the right threaded
state when the state is configured on the device level.
We chose not to have an "unset" state for threaded, and not to wipe
the NAPI config clean when channels are explicitly disabled.
This means the persistent config structs "exist" even when their NAPIs
are not instantiated.
Differently put - the NAPI persistent state lives in the net_device
(ncfg == struct napi_config):
,--- [napi 0] - [napi 1]
[dev] | |
`--- [ncfg 0] - [ncfg 1]
so say we a device with 2 queues but only 1 enabled:
,--- [napi 0]
[dev] |
`--- [ncfg 0] - [ncfg 1]
now we set the device to threaded=1:
,---------- [napi 0 (thr:1)]
[dev(thr:1)] |
`---------- [ncfg 0 (thr:1)] - [ncfg 1 (thr:?)]
Since [ncfg 1] was not attached to a NAPI during configuration we
skipped it. If we create a NAPI for it later it will have the old
setting (presumably disabled). One could argue if this is right
or not "in principle", but it's definitely not how things worked
before per-NAPI config..
Fixes: 2677010e77 ("Add support to set NAPI threaded for individual NAPI")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20250809001205.1147153-3-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Instead of using '0' and '1' for napi threaded state use an enum with
'disabled' and 'enabled' states.
Tested:
./tools/testing/selftests/net/nl_netdev.py
TAP version 13
1..7
ok 1 nl_netdev.empty_check
ok 2 nl_netdev.lo_check
ok 3 nl_netdev.page_pool_check
ok 4 nl_netdev.napi_list_check
ok 5 nl_netdev.dev_set_threaded
ok 6 nl_netdev.napi_set_threaded
ok 7 nl_netdev.nsim_rxq_reset_down
# Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250723013031.2911384-4-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Prepare for adding an enum type for NAPI threaded states by adding
netif_threaded_enable API. De-export the existing netif_set_threaded API
and only use it internally. Update existing drivers to use
netif_threaded_enable instead of the de-exported netif_set_threaded.
Note that dev_set_threaded used by mt76 debugfs file is unchanged.
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Link: https://patch.msgid.link/20250723013031.2911384-3-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
netif_close_many is used only by vlan/dsa and one mtk driver, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-8-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
Note that one dev_set_threaded call still remains in mt76 for debugfs file.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-7-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-6-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
__netif_set_mtu is used only by bond, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-5-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
netif_pre_changeaddr_notify is used only by ipvlan/bond, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-4-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
netif_get_mac_address is used only by tun/tap, so move it into
NETDEV_INTERNAL namespace.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-3-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit cc34acd577 ("docs: net: document new locking reality")
introduced netif_ vs dev_ function semantics: the former expects locked
netdev, the latter takes care of the locking. We don't strictly
follow this semantics on either side, but there are more dev_xxx handlers
now that don't fit. Rename them to netif_xxx where appropriate.
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250717172333.1288349-2-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A net device has a threaded sysctl that can be used to enable threaded
NAPI polling on all of the NAPI contexts under that device. Allow
enabling threaded NAPI polling at individual NAPI level using netlink.
Extend the netlink operation `napi-set` and allow setting the threaded
attribute of a NAPI. This will enable the threaded polling on a NAPI
context.
Add a test in `nl_netdev.py` that verifies various cases of threaded
NAPI being set at NAPI and at device level.
Tested
./tools/testing/selftests/net/nl_netdev.py
TAP version 13
1..7
ok 1 nl_netdev.empty_check
ok 2 nl_netdev.lo_check
ok 3 nl_netdev.page_pool_check
ok 4 nl_netdev.napi_list_check
ok 5 nl_netdev.dev_set_threaded
ok 6 nl_netdev.napi_set_threaded
ok 7 nl_netdev.nsim_rxq_reset_down
# Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250710211203.3979655-1-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This is a follow-up for commit eb1ac9ff6c ("ipv6: anycast: Don't
hold RTNL for IPV6_JOIN_ANYCAST.").
We should not add a new device lookup API without netdevice_tracker.
Let's pass netdevice_tracker to dev_get_by_flags_rcu() and rename it
with netdev_ prefix to match other newer APIs.
Note that we always use GFP_ATOMIC for netdev_hold() as it's expected
to be called under RCU.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/netdev/20250708184053.102109f6@kernel.org/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250711051120.2866855-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
inet6_sk(sk)->ipv6_ac_list is protected by lock_sock().
In ipv6_sock_ac_join(), only __dev_get_by_index(), __dev_get_by_flags(),
and __in6_dev_get() require RTNL.
__dev_get_by_flags() is only used by ipv6_sock_ac_join() and can be
converted to RCU version.
Let's replace RCU version helper and drop RTNL from IPV6_JOIN_ANYCAST.
setsockopt_needs_rtnl() will be removed in the next patch.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250702230210.3115355-15-kuni1840@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ethtool_notify() takes a const void *data argument, which presumably
was intended to pass information from the call site to the subcommand
handler. This argument currently has no users.
Expecting the data to be subcommand-specific has two complications.
Complication #1 is that its not plumbed thru any of the standardized
callbacks. It gets propagated to ethnl_default_notify() where it
remains unused. Coming from the ethnl_default_set_doit() side we pass
in NULL, because how could we have a command specific attribute in
a generic handler.
Complication #2 is that we expect the ethtool_notify() callers to
know what attribute type to pass in. Again, the data pointer is
untyped.
RSS will need to pass the context ID to the notifications.
I think it's a better design if the "subcommand" exports its own
typed interface and constructs the appropriate argument struct
(which will be req_info). Remove the unused data argument from
ethtool_notify() but retain it in a new internal helper which
subcommands can use to build a typed interface.
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20250623231720.3124717-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce the dev_dstats_rx_dropped_add() helper to allow incrementing
the rx_drops per-CPU statistic by an arbitrary value, rather than just
one. This is useful for drivers or code paths that need to account for
multiple dropped packets at once, such as when dropping entire queues.
Reviewed-by: Joe Damato <joe@dama.to>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250618-netdevsim_stat-v4-3-19fe0d35e28e@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
phys_port_id_show, phys_port_name_show and phys_switch_id_show would
return -EOPNOTSUPP if the netdev didn't implement the corresponding
method.
There is no point in creating these files if they are unsupported.
Put these attributes in netdev_phys_group and implement the is_visible
method. make phys_(port_id, port_name, switch_id) invisible if the netdev
dosen't implement the corresponding method.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250612142707.4644-1-yajun.deng@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Convert callers of dev_set_mac_address_user() to use struct
sockaddr_storage. Add sanity checks on dev->addr_len usage.
Signed-off-by: Kees Cook <kees@kernel.org>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://patch.msgid.link/20250521204619.2301870-8-kees@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
All users of dev_set_mac_address() are now using a struct sockaddr_storage.
Convert the internal data type to struct sockaddr_storage, drop the casts,
and update pointer types.
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20250521204619.2301870-6-kees@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In order to avoid passing around struct sockaddr that has a size the
compiler cannot reason about (nor track at runtime), convert
netif_set_mac_address() to take struct sockaddr_storage. This is just a
cast conversion, so there is are no binary changes. Following patches
will make actual allocation changes.
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20250521204619.2301870-2-kees@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'ipsec-next-2025-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:
====================
1) Remove some unnecessary strscpy_pad() size arguments.
From Thorsten Blum.
2) Correct use of xso.real_dev on bonding offloads.
Patchset from Cosmin Ratiu.
3) Add hardware offload configuration to XFRM_MSG_MIGRATE.
From Chiachang Wang.
4) Refactor migration setup during cloning. This was
done after the clone was created. Now it is done
in the cloning function itself.
From Chiachang Wang.
5) Validate assignment of maximal possible SEQ number.
Prevent from setting to the maximum sequrnce number
as this would cause for traffic drop.
From Leon Romanovsky.
6) Prevent configuration of interface index when offload
is used. Hardware can't handle this case.i
From Leon Romanovsky.
7) Always use kfree_sensitive() for SA secret zeroization.
From Zilin Guan.
ipsec-next-2025-05-23
* tag 'ipsec-next-2025-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
xfrm: use kfree_sensitive() for SA secret zeroization
xfrm: prevent configuration of interface index when offload is used
xfrm: validate assignment of maximal possible SEQ number
xfrm: Refactor migration setup during the cloning process
xfrm: Migrate offload configuration
bonding: Fix multiple long standing offload races
bonding: Mark active offloaded xfrm_states
xfrm: Add explicit dev to .xdo_dev_state_{add,delete,free}
xfrm: Remove unneeded device check from validate_xmit_xfrm
xfrm: Use xdo.dev instead of xdo.real_dev
net/mlx5: Avoid using xso.real_dev unnecessarily
xfrm: Remove unnecessary strscpy_pad() size arguments
====================
Link: https://patch.msgid.link/20250523075611.3723340-1-steffen.klassert@secunet.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
system_page_pool is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT
this data structure requires explicit locking.
Make a struct with a page_pool member (original system_page_pool) and a
local_lock_t and use local_lock_nested_bh() for locking. This change
adds only lockdep coverage and does not alter the functional behaviour
for !PREEMPT_RT.
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-6-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Update the for_each_netdev_in_bond_rcu macro to iterate through network
devices in the bond's network namespace instead of always using
init_net. This change is safe because:
1. **Bond-Slave Namespace Relationship**: A bond device and its slaves
must reside in the same network namespace. The bond device's
namespace is established at creation time and cannot change.
2. **Slave Movement Implications**: Any attempt to move a slave device
to a different namespace automatically removes it from the bond, as
per kernel networking stack rules.
This maintains the invariant that slaves must exist in the same
namespace as their bond.
This change is part of an effort to enable Link Aggregation (LAG) to
work properly inside custom network namespaces. Previously, the macro
would only find slave devices in the initial network namespace,
preventing proper bonding functionality in custom namespaces.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Link: https://patch.msgid.link/20250513081922.525716-1-mbloch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Drivers need to make sure not to pass netmem dma-addrs to the
dma-mapping API in order to support netmem TX.
Add helpers and netmem_dma_*() helpers that enables special handling of
netmem dma-addrs that drivers can use.
Document in netmem.rst what drivers need to do to support netmem TX.
Signed-off-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250508004830.4100853-7-almasrymina@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Accidentally spotted while trying to understand what else needs
to be renamed to netif_ prefix. Most of the calls to dev_set_promiscuity
are adjacent to dev_set_allmulti or dev_disable_lro so it should
be safe to add the lock. Note that new netif_set_promiscuity is
currently unused, the locked paths call __dev_set_promiscuity directly.
Fixes: ad7c7b2172 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250506011919.2882313-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Kuniyuki reports that the assert for netdev lock fires when
there are netdev event listeners (otherwise we skip the netlink
event generation).
Correct the locking when coming from the notifier.
The NETDEV_XDP_FEAT_CHANGE notifier is already fully locked,
it's the documentation that's incorrect.
Fixes: 99e44f39a8 ("netdev: depend on netdev->lock for xdp features")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Reported-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/20250410171019.62128-1-kuniyu@amazon.com
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250416030447.1077551-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Previously, device driver IPSec offload implementations would fall into
two categories:
1. Those that used xso.dev to determine the offload device.
2. Those that used xso.real_dev to determine the offload device.
The first category didn't work with bonding while the second did.
In a non-bonding setup the two pointers are the same.
This commit adds explicit pointers for the offload netdevice to
.xdo_dev_state_add() / .xdo_dev_state_delete() / .xdo_dev_state_free()
which eliminates the confusion and allows drivers from the first
category to work with bonding.
xso.real_dev now becomes a private pointer managed by the bonding
driver.
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
netdevice reg_state was split into two 16 bit enums back in 2010
in commit a2835763e1 ("rtnetlink: handle rtnl_link netlink
notifications manually"). Since the split the fields have been
moved apart, and last year we converted reg_state to a normal
u8 in commit 4d42b37def ("net: convert dev->reg_state to u8").
rtnl_link_state being a 16 bitfield makes no sense. Convert it
to a single bool, it seems very unlikely after 15 years that
we'll need more values in it.
We could drop dev->rtnl_link_ops from the conditions but feels
like having it there more clearly points at the reason for this
hack.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250410014246.780885-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
txq_trans_update() currently uses txq->xmit_lock_owner
to conditionally update txq->trans_start.
For regular devices, txq->xmit_lock_owner is updated
from HARD_TX_LOCK() and HARD_TX_UNLOCK(), and this apparently
causes cpu stalls.
Using dev->lltx, which sits in a read-mostly cache-line,
and already used in HARD_TX_LOCK() and HARD_TX_UNLOCK()
helps cpu prediction.
On an AMD EPYC 7B12 dual socket server, tcp_rr with 128 threads
and 30,000 flows gets a 5 % increase in throughput.
As explained in commit 95ecba62e2 ("net: fix races in
netdev_tx_sent_queue()/dev_watchdog()") I am planning
to no longer update txq->trans_start in the fast path
in a followup patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250408202742.2145516-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Protect xdp_features with netdev->lock. This way pure readers
no longer have to take rtnl_lock to access the field.
This includes calling NETDEV_XDP_FEAT_CHANGE under the lock.
Looks like that's fine for bonding, the only "real" listener,
it's the same as ethtool feature change.
In terms of normal drivers - only GVE need special consideration
(other drivers don't use instance lock or don't support XDP).
It calls xdp_set_features_flag() helper from gve_init_priv() which
in turn is called from gve_reset_recovery() (locked), or prior
to netdev registration. So switch to _locked.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Acked-by: Harshitha Ramamurthy <hramamurthy@google.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250408195956.412733-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Read accesses go via xsk_get_pool_from_qid(), the call coming
from the core and gve look safe (other "ops locked" drivers
don't support XSK).
Write accesses go via xsk_reg_pool_at_qid() and xsk_clear_pool_at_qid().
Former is already under the ops lock, latter is not (both coming from
the workqueue via xp_clear_dev() and NETDEV_UNREGISTER via xsk_notifier()).
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250408195956.412733-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netdev_get_by_index_lock() performs following steps:
rcu_lock();
dev = lookup(netns, ifindex);
dev_get(dev);
rcu_unlock();
[... lock & validate the dev ...]
return dev
Validation right now only checks if the device is registered but since
the lookup is netns-aware we must also protect against the device
switching netns right after we dropped the RCU lock. Otherwise
the caller in netns1 may get a pointer to a device which has just
switched to netns2.
We can't hold the lock for the entire netns change process (because of
the NETDEV_UNREGISTER notifier), and there's no existing marking to
indicate that the netns is unlisted because of netns move, so add one.
AFAIU none of the existing netdev_get_by_index_lock() callers can
suffer from this problem (NAPI code double checks the netns membership
and other callers are either under rtnl_lock or not ns-sensitive),
so this patch does not have to be treated as a fix.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250408195956.412733-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Callers of inetdev_init can come from several places with inconsistent
expectation about netdev instance lock. Grab instance lock during
REGISTER (plus UP). Also solve the inconsistency with UNREGISTER
where it was locked only during move netns path.
WARNING: CPU: 10 PID: 1479 at ./include/net/netdev_lock.h:54
__netdev_update_features+0x65f/0xca0
__warn+0x81/0x180
__netdev_update_features+0x65f/0xca0
report_bug+0x156/0x180
handle_bug+0x4f/0x90
exc_invalid_op+0x13/0x60
asm_exc_invalid_op+0x16/0x20
__netdev_update_features+0x65f/0xca0
netif_disable_lro+0x30/0x1d0
inetdev_init+0x12f/0x1f0
inetdev_event+0x48b/0x870
notifier_call_chain+0x38/0xf0
register_netdevice+0x741/0x8b0
register_netdev+0x1f/0x40
mlx5e_probe+0x4e3/0x8e0 [mlx5_core]
auxiliary_bus_probe+0x3f/0x90
really_probe+0xc3/0x3a0
__driver_probe_device+0x80/0x150
driver_probe_device+0x1f/0x90
__device_attach_driver+0x7d/0x100
bus_for_each_drv+0x80/0xd0
__device_attach+0xb4/0x1c0
bus_probe_device+0x91/0xa0
device_add+0x657/0x870
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: Cosmin Ratiu <cratiu@nvidia.com>
Fixes: ad7c7b2172 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250401163452.622454-3-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
netdev netlink is the only reader of netdev_{,rx_}queue->napi,
and it already holds netdev->lock. Switch protection of
the writes to netdev->lock to "ops protected".
The expectation will be now that accessing queue->napi
will require netdev->lock for "ops locked" drivers, and
rtnl_lock for all other drivers.
Current "ops locked" drivers don't require any changes.
gve and netdevsim use _locked() helpers right next to
netif_queue_set_napi() so they must be holding the instance
lock. iavf doesn't call it. bnxt is a bit messy but all paths
seem locked.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250324224537.248800-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Drivers which opt into instance lock protection of ops should
only call set_real_num_*_queues() under the instance lock.
This means that queue counts are double protected (writes
are under both rtnl_lock and instance lock, readers under
either).
Some readers may still be under the rtnl_lock, however, so for
now we need double protection of writers.
OTOH queue API paths are only under the protection of the instance
lock, so we need to validate that the instance is actually locking
ops, otherwise the input checks we do against queue count are racy.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250324224537.248800-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Try to define some terminology for which fields are protected
by which lock and how. Some fields are protected by both rtnl_lock
and instance lock which is hard to talk about without having
a "key phrase" to refer to a particular protection scheme.
"ops protected" fields are defined later in the series, one by one.
Add ASSERT_RTNL() to netdev_ops_assert_locked() for drivers
not other instance protection of ops. Hopefully it's not too
confusion that netdev_lock_ops() does not match the lock which
netdev_ops_assert_locked() will assert, exactly. The noun "ops"
is in a different place in the name, so I think it's acceptable...
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250324224537.248800-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since commit a953be53ce ("net-sysfs: add support for device-specific
rx queue sysfs attributes"), so for at least a decade now it is safe
to call net_rx_queue_update_kobjects() when SYSFS=n. That function
does its own ifdef-inery and will return 0. Remove the unnecessary
stub for netif_set_real_num_rx_queues().
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250324224537.248800-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently network taps unbound to any interface are linked in the
global ptype_all list, affecting the performance in all the network
namespaces.
Add per netns ptypes chains, so that in the mentioned case only
the netns owning the packet socket(s) is affected.
While at that drop the global ptype_all list: no in kernel user
registers a tap on "any" type without specifying either the target
device or the target namespace (and IMHO doing that would not make
any sense).
Note that this adds a conditional in the fast path (to check for
per netns ptype_specific list) and increases the dataset size by
a cacheline (owing the per netns lists).
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumaze@google.com>
Link: https://patch.msgid.link/ae405f98875ee87f8150c460ad162de7e466f8a7.1742494826.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Handling the CWR flag differs between RFC 3168 ECN and AccECN.
With RFC 3168 ECN aware TSO (NETIF_F_TSO_ECN) CWR flag is cleared
starting from 2nd segment which is incompatible how AccECN handles
the CWR flag. Such super-segments are indicated by SKB_GSO_TCP_ECN.
With AccECN, CWR flag (or more accurately, the ACE field that also
includes ECE & AE flags) changes only when new packet(s) with CE
mark arrives so the flag should not be changed within a super-skb.
The new skb/feature flags are necessary to prevent such TSO engines
corrupting AccECN ACE counters by clearing the CWR flag (if the
CWR handling feature cannot be turned off).
If NIC is completely unaware of RFC3168 ECN (doesn't support
NETIF_F_TSO_ECN) or its TSO engine can be set to not touch CWR flag
despite supporting also NETIF_F_TSO_ECN, TSO could be safely used
with AccECN on such NIC. This should be evaluated per NIC basis
(not done in this patch series for any NICs).
For the cases, where TSO cannot keep its hands off the CWR flag,
a GSO fallback is provided by this patch.
Signed-off-by: Ilpo Järvinen <ij@kernel.org>
Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a couple of places from which we can arrive to ndo_setup_tc
with TC_SETUP_BLOCK/TC_SETUP_FT:
- netlink
- netlink notifier
- netdev notifier
Locking netdev too deep in this call chain seems to be problematic
(especially assuming some/all of the call_netdevice_notifiers
NETDEV_UNREGISTER) might soon be running with the instance lock).
Revert to lockless ndo_setup_tc for TC_SETUP_BLOCK/TC_SETUP_FT. NFT
framework already takes care of most of the locking. Document
the assumptions.
ndo_setup_tc TC_SETUP_BLOCK
nft_block_offload_cmd
nft_chain_offload_cmd
nft_flow_block_chain
nft_flow_offload_chain
nft_flow_rule_offload_abort
nft_flow_rule_offload_commit
nft_flow_rule_offload_commit
nf_tables_commit
nfnetlink_rcv_batch
nfnetlink_rcv_skb_batch
nfnetlink_rcv
nft_offload_netdev_event
NETDEV_UNREGISTER notifier
ndo_setup_tc TC_SETUP_FT
nf_flow_table_offload_cmd
nf_flow_table_offload_setup
nft_unregister_flowtable_hook
nft_register_flowtable_net_hooks
nft_flowtable_update
nf_tables_newflowtable
nfnetlink_rcv_batch (.call NFNL_CB_BATCH)
nft_flowtable_update
nf_tables_newflowtable
nft_flowtable_event
nf_tables_flowtable_event
NETDEV_UNREGISTER notifier
__nft_unregister_flowtable_net_hooks
nft_unregister_flowtable_net_hooks
nf_tables_commit
nfnetlink_rcv_batch (.call NFNL_CB_BATCH)
__nf_tables_abort
nf_tables_abort
nfnetlink_rcv_batch
__nft_release_hook
__nft_release_hooks
nf_tables_pre_exit_net -> module unload
nft_rcv_nl_event
netlink_register_notifier (oh boy)
nft_register_flowtable_net_hooks
nft_flowtable_update
nf_tables_newflowtable
nf_tables_newflowtable
Fixes: c4f0f30b42 ("net: hold netdev instance lock during nft ndo_setup_tc")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Reported-by: syzbot+0afb4bcf91e5a1afdcad@syzkaller.appspotmail.com
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250308044726.1193222-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move the more esoteric helpers for netdev instance lock to
a dedicated header. This avoids growing netdevice.h to infinity
and makes rebuilding the kernel much faster (after touching
the header with the helpers).
The main netdev_lock() / netdev_unlock() functions are used
in static inlines in netdevice.h and will probably be used
most commonly, so keep them in netdevice.h.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Only devlink and sriov paths are grabbing rtnl explicitly. The rest is
covered by netdev instance lock which the core now grabs, so there is
no need to manage rtnl in most places anymore.
On the core side we can now try to drop rtnl in some places
(do_setlink for example) for the drivers that signal non-rtnl
mode (TBD).
Boot-tested and with `ethtool -L eth1 combined 24` to trigger reset.
Cc: Saeed Mahameed <saeed@kernel.org>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-15-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Also clarify ndo_get_stats (that read and write paths can run
concurrently) and mention only RCU.
Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-14-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently only the drivers that implement shaper or queue APIs
are grabbing instance lock. Add an explicit opt-in for the
drivers that want to grab the lock without implementing the above
APIs.
There is a 3-byte hole after @up, use it:
/* --- cacheline 47 boundary (3008 bytes) --- */
u32 napi_defer_hard_irqs; /* 3008 4 */
bool up; /* 3012 1 */
/* XXX 3 bytes hole, try to pack */
struct mutex lock; /* 3016 144 */
/* XXX last struct has 1 hole */
Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-13-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
