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2025-04-09netdev: add "ops compat locking" helpersJakub Kicinski
Add helpers to "lock a netdev in a backward-compatible way", which for ops-locked netdevs will mean take the instance lock. For drivers which haven't opted into the ops locking we'll take rtnl_lock. The scoped foreach is dropping and re-taking the lock for each device, even if prev and next are both under rtnl_lock. I hope that's fine since we expect that netdev nl to be mostly supported by modern drivers, and modern drivers should also opt into the instance locking. Note that these helpers are mostly needed for queue related state, because drivers modify queue config in their ops in a non-atomic way. Or differently put, queue changes don't have a clear-cut API like NAPI configuration. Any state that can should just use the instance lock directly, not the "compat" hacks. Reviewed-by: Joe Damato <jdamato@fastly.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250408195956.412733-4-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-09net: avoid potential race between netdev_get_by_index_lock() and netns switchJakub Kicinski
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>
2025-04-08net: rps: remove kfree_rcu_mightsleep() useEric Dumazet
Add an rcu_head to sd_flow_limit and rps_sock_flow_table structs to use the more conventional and predictable k[v]free_rcu(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250407163602.170356-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-08net: rps: annotate data-races around (struct sd_flow_limit)->countEric Dumazet
softnet_seq_show() can read fl->count while another cpu updates this field from skb_flow_limit(). Make this field an 'unsigned int', as its only consumer only deals with 32 bit. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250407163602.170356-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-08net: rps: change skb_flow_limit() hash functionEric Dumazet
As explained in commit f3483c8e1da6 ("net: rfs: hash function change"), masking low order bits of skb_get_hash(skb) has low entropy. A NIC with 32 RX queues uses the 5 low order bits of rss key to select a queue. This means all packets landing to a given queue share the same 5 low order bits. Switch to hash_32() to reduce hash collisions. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250407163602.170356-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-19Revert "net: replace dev_addr_sem with netdev instance lock"Stanislav Fomichev
This reverts commit df43d8bf10316a7c3b1e47e3cc0057a54df4a5b8. Cc: Kohei Enju <enjuk@amazon.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Fixes: df43d8bf1031 ("net: replace dev_addr_sem with netdev instance lock") Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250312190513.1252045-2-sdf@fomichev.me Tested-by: Lei Yang <leiyang@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-08net: move misc netdev_lock flavors to a separate headerJakub Kicinski
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>
2025-03-06net: replace dev_addr_sem with netdev instance lockStanislav Fomichev
Lockdep reports possible circular dependency in [0]. Instead of fixing the ordering, replace global dev_addr_sem with netdev instance lock. Most of the paths that set/get mac are RTNL protected. Two places where it's not, convert to explicit locking: - sysfs address_show - dev_get_mac_address via dev_ioctl 0: https://netdev-3.bots.linux.dev/vmksft-forwarding-dbg/results/993321/24-router-bridge-1d-lag-sh/stderr Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250305163732.2766420-12-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-06net: hold netdev instance lock during rtnetlink operationsStanislav Fomichev
To preserve the atomicity, hold the lock while applying multiple attributes. The major issue with a full conversion to the instance lock are software nesting devices (bonding/team/vrf/etc). Those devices call into the core stack for their lower (potentially real hw) devices. To avoid explicitly wrapping all those places into instance lock/unlock, introduce new API boundaries: - (some) existing dev_xxx calls are now considered "external" (to drivers) APIs and they transparently grab the instance lock if needed (dev_api.c) - new netif_xxx calls are internal core stack API (naming is sketchy, I've tried netdev_xxx_locked per Jakub's suggestion, but it feels a bit verbose; but happy to get back to this naming scheme if this is the preference) This avoids touching most of the existing ioctl/sysfs/drivers paths. Note the special handling of ndo_xxx_slave operations: I exploit the fact that none of the drivers that call these functions need/use instance lock. At the same time, they use dev_xxx APIs, so the lower device has to be unlocked. Changes in unregister_netdevice_many_notify (to protect dev->state with instance lock) trigger lockdep - the loop over close_list (mostly from cleanup_net) introduces spurious ordering issues. netdev_lock_cmp_fn has a justification on why it's ok to suppress for now. Cc: Saeed Mahameed <saeed@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250305163732.2766420-7-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-06net: hold netdev instance lock during ndo_open/ndo_stopStanislav Fomichev
For the drivers that use shaper API, switch to the mode where core stack holds the netdev lock. This affects two drivers: * iavf - already grabs netdev lock in ndo_open/ndo_stop, so mostly remove these * netdevsim - switch to _locked APIs to avoid deadlock iavf_close diff is a bit confusing, the existing call looks like this: iavf_close() { netdev_lock() .. netdev_unlock() wait_event_timeout(down_waitqueue) } I change it to the following: netdev_lock() iavf_close() { .. netdev_unlock() wait_event_timeout(down_waitqueue) netdev_lock() // reusing this lock call } netdev_unlock() Since I'm reusing existing netdev_lock call, so it looks like I only add netdev_unlock. Cc: Saeed Mahameed <saeed@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250305163732.2766420-2-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-07net: page_pool: avoid false positive warning if NAPI was never addedJakub Kicinski
We expect NAPI to be in disabled state when page pool is torn down. But it is also legal if the NAPI is completely uninitialized. Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250206225638.1387810-4-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: make netdev netlink ops hold netdev_lock()Jakub Kicinski
In prep for dropping rtnl_lock, start locking netdev->lock in netlink genl ops. We need to be using netdev->up instead of flags & IFF_UP. We can remove the RCU lock protection for the NAPI since NAPI list is protected by netdev->lock already. Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250115035319.559603-8-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: add netdev->up protected by netdev_lock()Jakub Kicinski
Some uAPI (netdev netlink) hide net_device's sub-objects while the interface is down to ensure uniform behavior across drivers. To remove the rtnl_lock dependency from those uAPIs we need a way to safely tell if the device is down or up. Add an indication of whether device is open or closed, protected by netdev->lock. The semantics are the same as IFF_UP, but taking netdev_lock around every write to ->flags would be a lot of code churn. We don't want to blanket the entire open / close path by netdev_lock, because it will prevent us from applying it to specific structures - core helpers won't be able to take that lock from any function called by the drivers on open/close paths. So the state of the flag is "pessimistic", as in it may report false negatives, but never false positives. Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250115035319.559603-5-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: add helpers for lookup and walking netdevs under netdev_lock()Jakub Kicinski
Add helpers for accessing netdevs under netdev_lock(). There's some careful handling needed to find the device and lock it safely, without it getting unregistered, and without taking rtnl_lock (the latter being the whole point of the new locking, after all). Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250115035319.559603-4-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-10net: hide the definition of dev_get_by_napi_id()Jakub Kicinski
There are no module callers of dev_get_by_napi_id(), and commit d1cacd747768 ("netdev: prevent accessing NAPI instances from another namespace") proves that getting NAPI by id needs to be done with care. So hide dev_get_by_napi_id(). Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250110004924.3212260-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.13-rc7). Conflicts: a42d71e322a8 ("net_sched: sch_cake: Add drop reasons") 737d4d91d35b ("sched: sch_cake: add bounds checks to host bulk flow fairness counts") Adjacent changes: drivers/net/ethernet/meta/fbnic/fbnic.h 3a856ab34726 ("eth: fbnic: add IRQ reuse support") 95978931d55f ("eth: fbnic: Revert "eth: fbnic: Add hardware monitoring support via HWMON interface"") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-08netdev: prevent accessing NAPI instances from another namespaceJakub Kicinski
The NAPI IDs were not fully exposed to user space prior to the netlink API, so they were never namespaced. The netlink API must ensure that at the very least NAPI instance belongs to the same netns as the owner of the genl sock. napi_by_id() can become static now, but it needs to move because of dev_get_by_napi_id(). Cc: stable@vger.kernel.org Fixes: 1287c1ae0fc2 ("netdev-genl: Support setting per-NAPI config values") Fixes: 27f91aaf49b3 ("netdev-genl: Add netlink framework functions for napi") Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250106180137.1861472-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-16net: Make net_hwtstamp_validate accessibleKory Maincent
Make the net_hwtstamp_validate function accessible in prevision to use it from ethtool to validate the hwtstamp configuration before setting it. Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-12-16net: Make dev_get_hwtstamp_phylib accessibleKory Maincent
Make the dev_get_hwtstamp_phylib function accessible in prevision to use it from ethtool to read the hwtstamp current configuration. Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-11-11net: Add napi_struct parameter irq_suspend_timeoutMartin Karsten
Add a per-NAPI IRQ suspension parameter, which can be get/set with netdev-genl. This patch doesn't change any behavior but prepares the code for other changes in the following commits which use irq_suspend_timeout as a timeout for IRQ suspension. Signed-off-by: Martin Karsten <mkarsten@uwaterloo.ca> Co-developed-by: Joe Damato <jdamato@fastly.com> Signed-off-by: Joe Damato <jdamato@fastly.com> Tested-by: Joe Damato <jdamato@fastly.com> Tested-by: Martin Karsten <mkarsten@uwaterloo.ca> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Link: https://patch.msgid.link/20241109050245.191288-2-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-14net: napi: Add napi_configJoe Damato
Add a persistent NAPI config area for NAPI configuration to the core. Drivers opt-in to setting the persistent config for a NAPI by passing an index when calling netif_napi_add_config. napi_config is allocated in alloc_netdev_mqs, freed in free_netdev (after the NAPIs are deleted). Drivers which call netif_napi_add_config will have persistent per-NAPI settings: NAPI IDs, gro_flush_timeout, and defer_hard_irq settings. Per-NAPI settings are saved in napi_disable and restored in napi_enable. Co-developed-by: Martin Karsten <mkarsten@uwaterloo.ca> Signed-off-by: Martin Karsten <mkarsten@uwaterloo.ca> Signed-off-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241011184527.16393-6-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-14net: napi: Make gro_flush_timeout per-NAPIJoe Damato
Allow per-NAPI gro_flush_timeout setting. The existing sysfs parameter is respected; writes to sysfs will write to all NAPI structs for the device and the net_device gro_flush_timeout field. Reads from sysfs will read from the net_device field. The ability to set gro_flush_timeout on specific NAPI instances will be added in a later commit, via netdev-genl. Signed-off-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20241011184527.16393-4-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-14net: napi: Make napi_defer_hard_irqs per-NAPIJoe Damato
Add defer_hard_irqs to napi_struct in preparation for per-NAPI settings. The existing sysfs parameter is respected; writes to sysfs will write to all NAPI structs for the device and the net_device defer_hard_irq field. Reads from sysfs show the net_device field. The ability to set defer_hard_irqs on specific NAPI instances will be added in a later commit, via netdev-genl. Signed-off-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20241011184527.16393-2-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-10net-shapers: implement shaper cleanup on queue deletionPaolo Abeni
hook into netif_set_real_num_tx_queues() to cleanup any shaper configured on top of the to-be-destroyed TX queues. Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/6da4ee03cae2b2a757d7b59e88baf09cc94c5ef1.1728460186.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-10net-shapers: implement NL get operationPaolo Abeni
Introduce the basic infrastructure to implement the net-shaper core functionality. Each network devices carries a net-shaper cache, the NL get() operation fetches the data from such cache. The cache is initially empty, will be fill by the set()/group() operation implemented later and is destroyed at device cleanup time. The net_shaper_fill_handle(), net_shaper_ctx_init(), and net_shaper_generic_pre() implementations handle generic index type attributes, despite the current caller always pass a constant value to avoid more noise in later patches using them with different attributes. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/ddd10fd645a9367803ad02fca4a5664ea5ace170.1728460186.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24net: softnet_data: Make xmit per task.Sebastian Andrzej Siewior
Softirq is preemptible on PREEMPT_RT. Without a per-CPU lock in local_bh_disable() there is no guarantee that only one device is transmitting at a time. With preemption and multiple senders it is possible that the per-CPU `recursion' counter gets incremented by different threads and exceeds XMIT_RECURSION_LIMIT leading to a false positive recursion alert. The `more' member is subject to similar problems if set by one thread for one driver and wrongly used by another driver within another thread. Instead of adding a lock to protect the per-CPU variable it is simpler to make xmit per-task. Sending and receiving skbs happens always in thread context anyway. Having a lock to protected the per-CPU counter would block/ serialize two sending threads needlessly. It would also require a recursive lock to ensure that the owner can increment the counter further. Make the softnet_data.xmit a task_struct member on PREEMPT_RT. Add needed wrapper. Cc: Ben Segall <bsegall@google.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240620132727.660738-9-bigeasy@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-17net: Move dev_set_hwtstamp_phylib to net/core/dev.hKory Maincent
This declaration was added to the header to be called from ethtool. ethtool is separated from core for code organization but it is not really a separate entity, it controls very core things. As ethtool is an internal stuff it is not wise to have it in netdevice.h. Move the declaration to net/core/dev.h instead. Remove the EXPORT_SYMBOL_GPL call as ethtool can not be built as a module. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kory Maincent <kory.maincent@bootlin.com> Link: https://lore.kernel.org/r/20240612-feature_ptp_netnext-v15-2-b2a086257b63@bootlin.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-30net: move sysctl_skb_defer_max to net_hotdataEric Dumazet
sysctl_skb_defer_max is used in TCP fast path, move it to net_hodata. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240429134025.1233626-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-01net: move dev_xmit_recursion() helpers to net/core/dev.hEric Dumazet
Move dev_xmit_recursion() and friends to net/core/dev.h They are only used from net/core/dev.c and net/core/filter.c. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-01net: move kick_defer_list_purge() to net/core/dev.hEric Dumazet
kick_defer_list_purge() is defined in net/core/dev.c and used from net/core/skubff.c Because we need softnet_data, include <linux/netdevice.h> from net/core/dev.h Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-07net: move netdev_tstamp_prequeue into net_hotdataEric Dumazet
netdev_tstamp_prequeue is used in rx path. Move it to net_hotdata for better cache locality. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240306160031.874438-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-07net: move netdev_budget and netdev_budget to net_hotdataEric Dumazet
netdev_budget and netdev_budget are used in rx path (net_rx_action()) Move them into net_hotdata for better cache locality. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240306160031.874438-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-14net-sysfs: use dev_addr_sem to remove races in address_show()Eric Dumazet
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>
2024-01-29net: free altname using an RCU callbackJakub Kicinski
We had to add another synchronize_rcu() in recent fix. Bite the bullet and add an rcu_head to netdev_name_node, free from RCU. Note that name_node does not hold any reference on dev to which it points, but there must be a synchronize_rcu() on device removal path, so we should be fine. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-22net: fix removing a namespace with conflicting altnamesJakub Kicinski
Mark reports a BUG() when a net namespace is removed. kernel BUG at net/core/dev.c:11520! Physical interfaces moved outside of init_net get "refunded" to init_net when that namespace disappears. The main interface name may get overwritten in the process if it would have conflicted. We need to also discard all conflicting altnames. Recent fixes addressed ensuring that altnames get moved with the main interface, which surfaced this problem. Reported-by: Марк Коренберг <socketpair@gmail.com> Link: https://lore.kernel.org/all/CAEmTpZFZ4Sv3KwqFOY2WKDHeZYdi0O7N5H1nTvcGp=SAEavtDg@mail.gmail.com/ Fixes: 7663d522099e ("net: check for altname conflicts when changing netdev's netns") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-05net: core: synchronize link-watch when carrier is queriedJohannes Berg
There are multiple ways to query for the carrier state: through rtnetlink, sysfs, and (possibly) ethtool. Synchronize linkwatch work before these operations so that we don't have a situation where userspace queries the carrier state between the driver's carrier off->on transition and linkwatch running and expects it to work, when really (at least) TX cannot work until linkwatch has run. I previously posted a longer explanation of how this applies to wireless [1] but with this wireless can simply query the state before sending data, to ensure the kernel is ready for it. [1] https://lore.kernel.org/all/346b21d87c69f817ea3c37caceb34f1f56255884.camel@sipsolutions.net/ Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20231204214706.303c62768415.I1caedccae72ee5a45c9085c5eb49c145ce1c0dd5@changeid Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-04netdev-genl: Add netlink framework functions for napiAmritha Nambiar
Implement the netdev netlink framework functions for napi support. The netdev structure tracks all the napi instances and napi fields. The napi instances and associated parameters can be retrieved this way. Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com> Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Link: https://lore.kernel.org/r/170147333637.5260.14807433239805550815.stgit@anambiarhost.jf.intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-26Merge tag 'for-netdev' of ↵Jakub Kicinski
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-10-26 We've added 51 non-merge commits during the last 10 day(s) which contain a total of 75 files changed, 5037 insertions(+), 200 deletions(-). The main changes are: 1) Add open-coded task, css_task and css iterator support. One of the use cases is customizable OOM victim selection via BPF, from Chuyi Zhou. 2) Fix BPF verifier's iterator convergence logic to use exact states comparison for convergence checks, from Eduard Zingerman, Andrii Nakryiko and Alexei Starovoitov. 3) Add BPF programmable net device where bpf_mprog defines the logic of its xmit routine. It can operate in L3 and L2 mode, from Daniel Borkmann and Nikolay Aleksandrov. 4) Batch of fixes for BPF per-CPU kptr and re-enable unit_size checking for global per-CPU allocator, from Hou Tao. 5) Fix libbpf which eagerly assumed that SHT_GNU_verdef ELF section was going to be present whenever a binary has SHT_GNU_versym section, from Andrii Nakryiko. 6) Fix BPF ringbuf correctness to fold smp_mb__before_atomic() into atomic_set_release(), from Paul E. McKenney. 7) Add a warning if NAPI callback missed xdp_do_flush() under CONFIG_DEBUG_NET which helps checking if drivers were missing the former, from Sebastian Andrzej Siewior. 8) Fix missed RCU read-lock in bpf_task_under_cgroup() which was throwing a warning under sleepable programs, from Yafang Shao. 9) Avoid unnecessary -EBUSY from htab_lock_bucket by disabling IRQ before checking map_locked, from Song Liu. 10) Make BPF CI linked_list failure test more robust, from Kumar Kartikeya Dwivedi. 11) Enable samples/bpf to be built as PIE in Fedora, from Viktor Malik. 12) Fix xsk starving when multiple xsk sockets were associated with a single xsk_buff_pool, from Albert Huang. 13) Clarify the signed modulo implementation for the BPF ISA standardization document that it uses truncated division, from Dave Thaler. 14) Improve BPF verifier's JEQ/JNE branch taken logic to also consider signed bounds knowledge, from Andrii Nakryiko. 15) Add an option to XDP selftests to use multi-buffer AF_XDP xdp_hw_metadata and mark used XDP programs as capable to use frags, from Larysa Zaremba. 16) Fix bpftool's BTF dumper wrt printing a pointer value and another one to fix struct_ops dump in an array, from Manu Bretelle. * tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (51 commits) netkit: Remove explicit active/peer ptr initialization selftests/bpf: Fix selftests broken by mitigations=off samples/bpf: Allow building with custom bpftool samples/bpf: Fix passing LDFLAGS to libbpf samples/bpf: Allow building with custom CFLAGS/LDFLAGS bpf: Add more WARN_ON_ONCE checks for mismatched alloc and free selftests/bpf: Add selftests for netkit selftests/bpf: Add netlink helper library bpftool: Extend net dump with netkit progs bpftool: Implement link show support for netkit libbpf: Add link-based API for netkit tools: Sync if_link uapi header netkit, bpf: Add bpf programmable net device bpf: Improve JEQ/JNE branch taken logic bpf: Fold smp_mb__before_atomic() into atomic_set_release() bpf: Fix unnecessary -EBUSY from htab_lock_bucket xsk: Avoid starving the xsk further down the list bpf: print full verifier states on infinite loop detection selftests/bpf: test if state loops are detected in a tricky case bpf: correct loop detection for iterators convergence ... ==================== Link: https://lore.kernel.org/r/20231026150509.2824-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-19net: check for altname conflicts when changing netdev's netnsJakub Kicinski
It's currently possible to create an altname conflicting with an altname or real name of another device by creating it in another netns and moving it over: [ ~]$ ip link add dev eth0 type dummy [ ~]$ ip netns add test [ ~]$ ip -netns test link add dev ethX netns test type dummy [ ~]$ ip -netns test link property add dev ethX altname eth0 [ ~]$ ip -netns test link set dev ethX netns 1 [ ~]$ ip link ... 3: eth0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 02:40:88:62:ec:b8 brd ff:ff:ff:ff:ff:ff ... 5: ethX: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 26:b7:28:78:38:0f brd ff:ff:ff:ff:ff:ff altname eth0 Create a macro for walking the altnames, this hopefully makes it clearer that the list we walk contains only altnames. Which is otherwise not entirely intuitive. Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames") Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-10-17net, bpf: Add a warning if NAPI cb missed xdp_do_flush().Sebastian Andrzej Siewior
A few drivers were missing a xdp_do_flush() invocation after XDP_REDIRECT. Add three helper functions each for one of the per-CPU lists. Return true if the per-CPU list is non-empty and flush the list. Add xdp_do_check_flushed() which invokes each helper functions and creates a warning if one of the functions had a non-empty list. Hide everything behind CONFIG_DEBUG_NET. Suggested-by: Jesper Dangaard Brouer <hawk@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20231016125738.Yt79p1uF@linutronix.de
2023-02-09net-sysctl: factor-out rpm mask manipulation helpersPaolo Abeni
Will simplify the following patch. No functional change intended. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-01net: add gso_ipv4_max_size and gro_ipv4_max_size per deviceXin Long
This patch introduces gso_ipv4_max_size and gro_ipv4_max_size per device and adds netlink attributes for them, so that IPV4 BIG TCP can be guarded by a separate tunable in the next patch. To not break the old application using "gso/gro_max_size" for IPv4 GSO packets, this patch updates "gso/gro_ipv4_max_size" in netif_set_gso/gro_max_size() if the new size isn't greater than GSO_LEGACY_MAX_SIZE, so that nothing will change even if userspace doesn't realize the new netlink attributes. Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-31net: add new helper unregister_netdevice_many_notifyHangbin Liu
Add new helper unregister_netdevice_many_notify(), pass netlink message header and portid, which could be used to notify userspace when flag NLM_F_ECHO is set. Make the unregister_netdevice_many() as a wrapper of new function unregister_netdevice_many_notify(). Suggested-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-31rtnetlink: pass netlink message header and portid to rtnl_configure_link()Hangbin Liu
This patch pass netlink message header and portid to rtnl_configure_link() All the functions in this call chain need to add the parameters so we can use them in the last call rtnl_notify(), and notify the userspace about the new link info if NLM_F_ECHO flag is set. - rtnl_configure_link() - __dev_notify_flags() - rtmsg_ifinfo() - rtmsg_ifinfo_event() - rtmsg_ifinfo_build_skb() - rtmsg_ifinfo_send() - rtnl_notify() Also move __dev_notify_flags() declaration to net/core/dev.h, as Jakub suggested. Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-05-16net: add skb_defer_max sysctlEric Dumazet
commit 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") added another per-cpu cache of skbs. It was expected to be small, and an IPI was forced whenever the list reached 128 skbs. We might need to be able to control more precisely queue capacity and added latency. An IPI is generated whenever queue reaches half capacity. Default value of the new limit is 64. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-06net: move netif_set_gso_max helpersJakub Kicinski
These are now internal to the core, no need to expose them. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-04-07net: extract a few internals from netdevice.hJakub Kicinski
There's a number of functions and static variables used under net/core/ but not from the outside. We currently dump most of them into netdevice.h. That bad for many reasons: - netdevice.h is very cluttered, hard to figure out what the APIs are; - netdevice.h is very long; - we have to touch netdevice.h more which causes expensive incremental builds. Create a header under net/core/ and move some declarations. The new header is also a bit of a catch-all but that's fine, if we create more specific headers people will likely over-think where their declaration fit best. And end up putting them in netdevice.h, again. More work should be done on splitting netdevice.h into more targeted headers, but that'd be more time consuming so small steps. Signed-off-by: Jakub Kicinski <kuba@kernel.org>