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2025-03-07netmem: prevent TX of unreadable skbsMina Almasry
Currently on stable trees we have support for netmem/devmem RX but not TX. It is not safe to forward/redirect an RX unreadable netmem packet into the device's TX path, as the device may call dma-mapping APIs on dma addrs that should not be passed to it. Fix this by preventing the xmit of unreadable skbs. Tested by configuring tc redirect: sudo tc qdisc add dev eth1 ingress sudo tc filter add dev eth1 ingress protocol ip prio 1 flower ip_proto \ tcp src_ip 192.168.1.12 action mirred egress redirect dev eth1 Before, I see unreadable skbs in the driver's TX path passed to dma mapping APIs. After, I don't see unreadable skbs in the driver's TX path passed to dma mapping APIs. Fixes: 65249feb6b3d ("net: add support for skbs with unreadable frags") Suggested-by: Jakub Kicinski <kuba@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250306215520.1415465-1-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-26net: Handle napi_schedule() calls from non-interruptFrederic Weisbecker
napi_schedule() is expected to be called either: * From an interrupt, where raised softirqs are handled on IRQ exit * From a softirq disabled section, where raised softirqs are handled on the next call to local_bh_enable(). * From a softirq handler, where raised softirqs are handled on the next round in do_softirq(), or further deferred to a dedicated kthread. Other bare tasks context may end up ignoring the raised NET_RX vector until the next random softirq handling opportunity, which may not happen before a while if the CPU goes idle afterwards with the tick stopped. Such "misuses" have been detected on several places thanks to messages of the kind: "NOHZ tick-stop error: local softirq work is pending, handler #08!!!" For example: __raise_softirq_irqoff __napi_schedule rtl8152_runtime_resume.isra.0 rtl8152_resume usb_resume_interface.isra.0 usb_resume_both __rpm_callback rpm_callback rpm_resume __pm_runtime_resume usb_autoresume_device usb_remote_wakeup hub_event process_one_work worker_thread kthread ret_from_fork ret_from_fork_asm And also: * drivers/net/usb/r8152.c::rtl_work_func_t * drivers/net/netdevsim/netdev.c::nsim_start_xmit There is a long history of issues of this kind: 019edd01d174 ("ath10k: sdio: Add missing BH locking around napi_schdule()") 330068589389 ("idpf: disable local BH when scheduling napi for marker packets") e3d5d70cb483 ("net: lan78xx: fix "softirq work is pending" error") e55c27ed9ccf ("mt76: mt7615: add missing bh-disable around rx napi schedule") c0182aa98570 ("mt76: mt7915: add missing bh-disable around tx napi enable/schedule") 970be1dff26d ("mt76: disable BH around napi_schedule() calls") 019edd01d174 ("ath10k: sdio: Add missing BH locking around napi_schdule()") 30bfec4fec59 ("can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt") e63052a5dd3c ("mlx5e: add add missing BH locking around napi_schdule()") 83a0c6e58901 ("i40e: Invoke softirqs after napi_reschedule") bd4ce941c8d5 ("mlx4: Invoke softirqs after napi_reschedule") 8cf699ec849f ("mlx4: do not call napi_schedule() without care") ec13ee80145c ("virtio_net: invoke softirqs after __napi_schedule") This shows that relying on the caller to arrange a proper context for the softirqs to be handled while calling napi_schedule() is very fragile and error prone. Also fixing them can also prove challenging if the caller may be called from different kinds of contexts. Therefore fix this from napi_schedule() itself with waking up ksoftirqd when softirqs are raised from task contexts. Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Reported-by: Jakub Kicinski <kuba@kernel.org> Reported-by: Francois Romieu <romieu@fr.zoreil.com> Closes: https://lore.kernel.org/lkml/354a2690-9bbf-4ccb-8769-fa94707a9340@molgen.mpg.de/ Cc: Breno Leitao <leitao@debian.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250223221708.27130-1-frederic@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-26net: Use rtnl_net_dev_lock() in register_netdevice_notifier_dev_net().Kuniyuki Iwashima
Breno Leitao reported the splat below. [0] Commit 65161fb544aa ("net: Fix dev_net(dev) race in unregister_netdevice_notifier_dev_net().") added the DEBUG_NET_WARN_ON_ONCE(), assuming that the netdev is not registered before register_netdevice_notifier_dev_net(). But the assumption was simply wrong. Let's use rtnl_net_dev_lock() in register_netdevice_notifier_dev_net(). [0]: WARNING: CPU: 25 PID: 849 at net/core/dev.c:2150 register_netdevice_notifier_dev_net (net/core/dev.c:2150) <TASK> ? __warn (kernel/panic.c:242 kernel/panic.c:748) ? register_netdevice_notifier_dev_net (net/core/dev.c:2150) ? register_netdevice_notifier_dev_net (net/core/dev.c:2150) ? report_bug (lib/bug.c:? lib/bug.c:219) ? handle_bug (arch/x86/kernel/traps.c:285) ? exc_invalid_op (arch/x86/kernel/traps.c:309) ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) ? register_netdevice_notifier_dev_net (net/core/dev.c:2150) ? register_netdevice_notifier_dev_net (./include/net/net_namespace.h:406 ./include/linux/netdevice.h:2663 net/core/dev.c:2144) mlx5e_mdev_notifier_event+0x9f/0xf0 mlx5_ib notifier_call_chain.llvm.12241336988804114627 (kernel/notifier.c:85) blocking_notifier_call_chain (kernel/notifier.c:380) mlx5_core_uplink_netdev_event_replay (drivers/net/ethernet/mellanox/mlx5/core/main.c:352) mlx5_ib_roce_init.llvm.12447516292400117075+0x1c6/0x550 mlx5_ib mlx5r_probe+0x375/0x6a0 mlx5_ib ? kernfs_put (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-arch-fallback.h:2278 ./include/linux/atomic/atomic-instrumented.h:1384 fs/kernfs/dir.c:557) ? auxiliary_match_id (drivers/base/auxiliary.c:174) ? mlx5r_mp_remove+0x160/0x160 mlx5_ib really_probe (drivers/base/dd.c:? drivers/base/dd.c:658) driver_probe_device (drivers/base/dd.c:830) __driver_attach (drivers/base/dd.c:1217) bus_for_each_dev (drivers/base/bus.c:369) ? driver_attach (drivers/base/dd.c:1157) bus_add_driver (drivers/base/bus.c:679) driver_register (drivers/base/driver.c:249) Fixes: 7fb1073300a2 ("net: Hold rtnl_net_lock() in (un)?register_netdevice_notifier_dev_net().") Reported-by: Breno Leitao <leitao@debian.org> Closes: https://lore.kernel.org/netdev/20250224-noisy-cordial-roadrunner-fad40c@leitao/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Tested-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20250225211023.96448-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-20Revert "net: skb: introduce and use a single page frag cache"Paolo Abeni
After the previous commit is finally safe to revert commit dbae2b062824 ("net: skb: introduce and use a single page frag cache"): do it here. The intended goal of such change was to counter a performance regression introduced by commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for tiny skbs"). Unfortunately, the blamed commit introduces another regression for the virtio_net driver. Such a driver calls napi_alloc_skb() with a tiny size, so that the whole head frag could fit a 512-byte block. The single page frag cache uses a 1K fragment for such allocation, and the additional overhead, under small UDP packets flood, makes the page allocator a bottleneck. Thanks to commit bf9f1baa279f ("net: add dedicated kmem_cache for typical/small skb->head"), this revert does not re-introduce the original regression. Actually, in the relevant test on top of this revert, I measure a small but noticeable positive delta, just above noise level. The revert itself required some additional mangling due to recent updates in the affected code. Suggested-by: Eric Dumazet <edumazet@google.com> Fixes: dbae2b062824 ("net: skb: introduce and use a single page frag cache") Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-02-19net: Add non-RCU dev_getbyhwaddr() helperBreno Leitao
Add dedicated helper for finding devices by hardware address when holding rtnl_lock, similar to existing dev_getbyhwaddr_rcu(). This prevents PROVE_LOCKING warnings when rtnl_lock is held but RCU read lock is not. Extract common address comparison logic into dev_addr_cmp(). The context about this change could be found in the following discussion: Link: https://lore.kernel.org/all/20250206-scarlet-ermine-of-improvement-1fcac5@leitao/ Cc: kuniyu@amazon.com Cc: ushankar@purestorage.com Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250218-arm_fix_selftest-v5-1-d3d6892db9e1@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-18dev: Use rtnl_net_dev_lock() in unregister_netdev().Kuniyuki Iwashima
The following sequence is basically illegal when dev was fetched without lookup because dev_net(dev) might be different after holding rtnl_net_lock(): net = dev_net(dev); rtnl_net_lock(net); Let's use rtnl_net_dev_lock() in unregister_netdev(). Note that there is no real bug in unregister_netdev() for now because RTNL protects the scope even if dev_net(dev) is changed before/after RTNL. Fixes: 00fb9823939e ("dev: Hold per-netns RTNL in (un)?register_netdev().") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250217191129.19967-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-18net: Fix dev_net(dev) race in unregister_netdevice_notifier_dev_net().Kuniyuki Iwashima
After the cited commit, dev_net(dev) is fetched before holding RTNL and passed to __unregister_netdevice_notifier_net(). However, dev_net(dev) might be different after holding RTNL. In the reported case [0], while removing a VF device, its netns was being dismantled and the VF was moved to init_net. So the following sequence is basically illegal when dev was fetched without lookup: net = dev_net(dev); rtnl_net_lock(net); Let's use a new helper rtnl_net_dev_lock() to fix the race. It fetches dev_net_rcu(dev), bumps its net->passive, and checks if dev_net_rcu(dev) is changed after rtnl_net_lock(). [0]: BUG: KASAN: slab-use-after-free in notifier_call_chain (kernel/notifier.c:75 (discriminator 2)) Read of size 8 at addr ffff88810cefb4c8 by task test-bridge-lag/21127 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) print_report (mm/kasan/report.c:379 mm/kasan/report.c:489) kasan_report (mm/kasan/report.c:604) notifier_call_chain (kernel/notifier.c:75 (discriminator 2)) call_netdevice_notifiers_info (net/core/dev.c:2011) unregister_netdevice_many_notify (net/core/dev.c:11551) unregister_netdevice_queue (net/core/dev.c:11487) unregister_netdev (net/core/dev.c:11635) mlx5e_remove (drivers/net/ethernet/mellanox/mlx5/core/en_main.c:6552 drivers/net/ethernet/mellanox/mlx5/core/en_main.c:6579) mlx5_core auxiliary_bus_remove (drivers/base/auxiliary.c:230) device_release_driver_internal (drivers/base/dd.c:1275 drivers/base/dd.c:1296) bus_remove_device (./include/linux/kobject.h:193 drivers/base/base.h:73 drivers/base/bus.c:583) device_del (drivers/base/power/power.h:142 drivers/base/core.c:3855) mlx5_rescan_drivers_locked (./include/linux/auxiliary_bus.h:241 drivers/net/ethernet/mellanox/mlx5/core/dev.c:333 drivers/net/ethernet/mellanox/mlx5/core/dev.c:535 drivers/net/ethernet/mellanox/mlx5/core/dev.c:549) mlx5_core mlx5_unregister_device (drivers/net/ethernet/mellanox/mlx5/core/dev.c:468) mlx5_core mlx5_uninit_one (./include/linux/instrumented.h:68 ./include/asm-generic/bitops/instrumented-non-atomic.h:141 drivers/net/ethernet/mellanox/mlx5/core/main.c:1563) mlx5_core remove_one (drivers/net/ethernet/mellanox/mlx5/core/main.c:965 drivers/net/ethernet/mellanox/mlx5/core/main.c:2019) mlx5_core pci_device_remove (./include/linux/pm_runtime.h:129 drivers/pci/pci-driver.c:475) device_release_driver_internal (drivers/base/dd.c:1275 drivers/base/dd.c:1296) unbind_store (drivers/base/bus.c:245) kernfs_fop_write_iter (fs/kernfs/file.c:338) vfs_write (fs/read_write.c:587 (discriminator 1) fs/read_write.c:679 (discriminator 1)) ksys_write (fs/read_write.c:732) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f6a4d5018b7 Fixes: 7fb1073300a2 ("net: Hold rtnl_net_lock() in (un)?register_netdevice_notifier_dev_net().") Reported-by: Yael Chemla <ychemla@nvidia.com> Closes: https://lore.kernel.org/netdev/146eabfe-123c-4970-901e-e961b4c09bc3@nvidia.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250217191129.19967-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-03net: harmonize tstats and dstatsPaolo Abeni
After the blamed commits below, some UDP tunnel use dstats for accounting. On the xmit path, all the UDP-base tunnels ends up using iptunnel_xmit_stats() for stats accounting, and the latter assumes the relevant (tunnel) network device uses tstats. The end result is some 'funny' stat report for the mentioned UDP tunnel, e.g. when no packet is actually dropped and a bunch of packets are transmitted: gnv2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue \ state UNKNOWN mode DEFAULT group default qlen 1000 link/ether ee:7d:09:87:90:ea brd ff:ff:ff:ff:ff:ff RX: bytes packets errors dropped missed mcast 14916 23 0 15 0 0 TX: bytes packets errors dropped carrier collsns 0 1566 0 0 0 0 Address the issue ensuring the same binary layout for the overlapping fields of dstats and tstats. While this solution is a bit hackish, is smaller and with no performance pitfall compared to other alternatives i.e. supporting both dstat and tstat in iptunnel_xmit_stats() or reverting the blamed commit. With time we should possibly move all the IP-based tunnel (and virtual devices) to dstats. Fixes: c77200c07491 ("bareudp: Handle stats using NETDEV_PCPU_STAT_DSTATS.") Fixes: 6fa6de302246 ("geneve: Handle stats using NETDEV_PCPU_STAT_DSTATS.") Fixes: be226352e8dc ("vxlan: Handle stats using NETDEV_PCPU_STAT_DSTATS.") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/2e1c444cf0f63ae472baff29862c4c869be17031.1738432804.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-30net: revert RTNL changes in unregister_netdevice_many_notify()Eric Dumazet
This patch reverts following changes: 83419b61d187 net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 2) ae646f1a0bb9 net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 1) cfa579f66656 net: no longer hold RTNL while calling flush_all_backlogs() This caused issues in layers holding a private mutex: cleanup_net() rtnl_lock(); mutex_lock(subsystem_mutex); unregister_netdevice(); rtnl_unlock(); // LOCKDEP violation rtnl_lock(); I will revisit this in next cycle, opt-in for the new behavior from safe contexts only. Fixes: cfa579f66656 ("net: no longer hold RTNL while calling flush_all_backlogs()") Fixes: ae646f1a0bb9 ("net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 1)") Fixes: 83419b61d187 ("net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 2)") Reported-by: syzbot+5b9196ecf74447172a9a@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6789d55f.050a0220.20d369.004e.GAE@google.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250129142726.747726-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-29net: xdp: Disallow attaching device-bound programs in generic modeToke Høiland-Jørgensen
Device-bound programs are used to support RX metadata kfuncs. These kfuncs are driver-specific and rely on the driver context to read the metadata. This means they can't work in generic XDP mode. However, there is no check to disallow such programs from being attached in generic mode, in which case the metadata kfuncs will be called in an invalid context, leading to crashes. Fix this by adding a check to disallow attaching device-bound programs in generic mode. Fixes: 2b3486bc2d23 ("bpf: Introduce device-bound XDP programs") Reported-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de> Closes: https://lore.kernel.org/r/dae862ec-43b5-41a0-8edf-46c59071cdda@hetzner-cloud.de Tested-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20250127131344.238147-1-toke@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-27net: page_pool: don't try to stash the napi idJakub Kicinski
Page ppol tried to cache the NAPI ID in page pool info to avoid having a dependency on the life cycle of the NAPI instance. Since commit under Fixes the NAPI ID is not populated until napi_enable() and there's a good chance that page pool is created before NAPI gets enabled. Protect the NAPI pointer with the existing page pool mutex, the reading path already holds it. napi_id itself we need to READ_ONCE(), it's protected by netdev_lock() which are not holding in page pool. Before this patch napi IDs were missing for mlx5: # ./cli.py --spec netlink/specs/netdev.yaml --dump page-pool-get [{'id': 144, 'ifindex': 2, 'inflight': 3072, 'inflight-mem': 12582912}, {'id': 143, 'ifindex': 2, 'inflight': 5568, 'inflight-mem': 22806528}, {'id': 142, 'ifindex': 2, 'inflight': 5120, 'inflight-mem': 20971520}, {'id': 141, 'ifindex': 2, 'inflight': 4992, 'inflight-mem': 20447232}, ... After: [{'id': 144, 'ifindex': 2, 'inflight': 3072, 'inflight-mem': 12582912, 'napi-id': 565}, {'id': 143, 'ifindex': 2, 'inflight': 4224, 'inflight-mem': 17301504, 'napi-id': 525}, {'id': 142, 'ifindex': 2, 'inflight': 4288, 'inflight-mem': 17563648, 'napi-id': 524}, ... Fixes: 86e25f40aa1e ("net: napi: Add napi_config") Reviewed-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20250123231620.1086401-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20net: provide pending ring configuration in net_deviceJakub Kicinski
Record the pending configuration in net_device struct. ethtool core duplicates the current config and the specific handlers (for now just ringparam) can modify it. Reviewed-by: Michael Chan <michael.chan@broadcom.com> Link: https://patch.msgid.link/20250119020518.1962249-4-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20net: move HDS config from ethtool stateJakub Kicinski
Separate the HDS config from the ethtool state struct. The HDS config contains just simple parameters, not state. Having it as a separate struct will make it easier to clone / copy and also long term potentially make it per-queue. Reviewed-by: Michael Chan <michael.chan@broadcom.com> Link: https://patch.msgid.link/20250119020518.1962249-2-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-20net: sched: refine software bypass handling in tc_runXin Long
This patch addresses issues with filter counting in block (tcf_block), particularly for software bypass scenarios, by introducing a more accurate mechanism using useswcnt. Previously, filtercnt and skipswcnt were introduced by: Commit 2081fd3445fe ("net: sched: cls_api: add filter counter") and Commit f631ef39d819 ("net: sched: cls_api: add skip_sw counter") filtercnt tracked all tp (tcf_proto) objects added to a block, and skipswcnt counted tp objects with the skipsw attribute set. The problem is: a single tp can contain multiple filters, some with skipsw and others without. The current implementation fails in the case: When the first filter in a tp has skipsw, both skipswcnt and filtercnt are incremented, then adding a second filter without skipsw to the same tp does not modify these counters because tp->counted is already set. This results in bypass software behavior based solely on skipswcnt equaling filtercnt, even when the block includes filters without skipsw. Consequently, filters without skipsw are inadvertently bypassed. To address this, the patch introduces useswcnt in block to explicitly count tp objects containing at least one filter without skipsw. Key changes include: Whenever a filter without skipsw is added, its tp is marked with usesw and counted in useswcnt. tc_run() now uses useswcnt to determine software bypass, eliminating reliance on filtercnt and skipswcnt. This refined approach prevents software bypass for blocks containing mixed filters, ensuring correct behavior in tc_run(). Additionally, as atomic operations on useswcnt ensure thread safety and tp->lock guards access to tp->usesw and tp->counted, the broader lock down_write(&block->cb_lock) is no longer required in tc_new_tfilter(), and this resolves a performance regression caused by the filter counting mechanism during parallel filter insertions. The improvement can be demonstrated using the following script: # cat insert_tc_rules.sh tc qdisc add dev ens1f0np0 ingress for i in $(seq 16); do taskset -c $i tc -b rules_$i.txt & done wait Each of rules_$i.txt files above includes 100000 tc filter rules to a mlx5 driver NIC ens1f0np0. Without this patch: # time sh insert_tc_rules.sh real 0m50.780s user 0m23.556s sys 4m13.032s With this patch: # time sh insert_tc_rules.sh real 0m17.718s user 0m7.807s sys 3m45.050s Fixes: 047f340b36fc ("net: sched: make skip_sw actually skip software") Reported-by: Shuang Li <shuali@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> Tested-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-01-18net: introduce netdev_napi_exit()Eric Dumazet
After 1b23cdbd2bbc ("net: protect netdev->napi_list with netdev_lock()") it makes sense to iterate through dev->napi_list while holding the device lock. Also call synchronize_net() at most one time. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250117232113.1612899-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-18net: destroy dev->lock later in free_netdev()Eric Dumazet
syzbot complained that free_netdev() was calling netif_napi_del() after dev->lock mutex has been destroyed. This fires a warning for CONFIG_DEBUG_MUTEXES=y builds. Move mutex_destroy(&dev->lock) near the end of free_netdev(). [1] DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 0 PID: 5971 at kernel/locking/mutex.c:564 __mutex_lock_common kernel/locking/mutex.c:564 [inline] WARNING: CPU: 0 PID: 5971 at kernel/locking/mutex.c:564 __mutex_lock+0xdac/0xee0 kernel/locking/mutex.c:735 Modules linked in: CPU: 0 UID: 0 PID: 5971 Comm: syz-executor Not tainted 6.13.0-rc7-syzkaller-01131-g8d20dcda404d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:564 [inline] RIP: 0010:__mutex_lock+0xdac/0xee0 kernel/locking/mutex.c:735 Code: 0f b6 04 38 84 c0 0f 85 1a 01 00 00 83 3d 6f 40 4c 04 00 75 19 90 48 c7 c7 60 84 0a 8c 48 c7 c6 00 85 0a 8c e8 f5 dc 91 f5 90 <0f> 0b 90 90 90 e9 c7 f3 ff ff 90 0f 0b 90 e9 29 f8 ff ff 90 0f 0b RSP: 0018:ffffc90003317580 EFLAGS: 00010246 RAX: ee0f97edaf7b7d00 RBX: ffff8880299f8cb0 RCX: ffff8880323c9e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003317710 R08: ffffffff81602ac2 R09: 1ffff110170c519a R10: dffffc0000000000 R11: ffffed10170c519b R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff92000662ec4 R15: dffffc0000000000 FS: 000055557a046500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd581d46ff8 CR3: 000000006f870000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> netdev_lock include/linux/netdevice.h:2691 [inline] __netif_napi_del include/linux/netdevice.h:2829 [inline] netif_napi_del include/linux/netdevice.h:2848 [inline] free_netdev+0x2d9/0x610 net/core/dev.c:11621 netdev_run_todo+0xf21/0x10d0 net/core/dev.c:11189 nsim_destroy+0x3c3/0x620 drivers/net/netdevsim/netdev.c:1028 __nsim_dev_port_del+0x14b/0x1b0 drivers/net/netdevsim/dev.c:1428 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1440 [inline] nsim_dev_reload_destroy+0x28a/0x490 drivers/net/netdevsim/dev.c:1661 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1676 device_remove drivers/base/dd.c:567 [inline] Fixes: 1b23cdbd2bbc ("net: protect netdev->napi_list with netdev_lock()") Reported-by: syzbot+85ff1051228a04613a32@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/678add43.050a0220.303755.0016.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250117224626.1427577-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-16dev: Hold rtnl_net_lock() for dev_ifsioc().Kuniyuki Iwashima
Basically, dev_ifsioc() operates on the passed single netns (except for netdev notifier chains with lower/upper devices for which we will need more changes). Let's hold rtnl_net_lock() for dev_ifsioc(). Now that NETDEV_CHANGENAME is always triggered under rtnl_net_lock() of the device's netns. (do_setlink() and dev_ifsioc()) Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250115095545.52709-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-16dev: Remove devnet_rename_sem.Kuniyuki Iwashima
devnet_rename_sem is no longer used since commit 0840556e5a3a ("net: Protect dev->name by seqlock."). Also, RTNL serialises dev_change_name(). Let's remove devnet_rename_sem. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250115095545.52709-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-16dev: Acquire netdev_rename_lock before restoring dev->name in dev_change_name().Kuniyuki Iwashima
The cited commit forgot to add netdev_rename_lock in one of the error paths in dev_change_name(). Let's hold netdev_rename_lock before restoring the old dev->name. Fixes: 0840556e5a3a ("net: Protect dev->name by seqlock.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250115095545.52709-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15Merge branch 'net-reduce-rtnl-pressure-in-unregister_netdevice'Jakub Kicinski
Eric Dumazet says: ==================== net: reduce RTNL pressure in unregister_netdevice() One major source of RTNL contention resides in unregister_netdevice() Due to RCU protection of various network structures, and unregister_netdevice() being a synchronous function, it is calling potentially slow functions while holding RTNL. I think we can release RTNL in two points, so that three slow functions are called while RTNL can be used by other threads. v1: https://lore.kernel.org/netdev/20250107130906.098fc8d6@kernel.org/T/#m398c95f5778e1ff70938e079d3c4c43c050ad2a6 ==================== Link: https://patch.msgid.link/20250114205531.967841-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 2)Eric Dumazet
One synchronize_net() call is currently done while holding RTNL. This is source of RTNL contention in workloads adding and deleting many network namespaces per second, because synchronize_rcu() and synchronize_rcu_expedited() can use 60+ ms in some cases. For cleanup_net() use, temporarily release RTNL while calling the last synchronize_net(). This should be safe, because devices are no longer visible to other threads after unlist_netdevice() call and setting dev->reg_state to NETREG_UNREGISTERING. In any case, the new netdev_lock() / netdev_unlock() infrastructure that we are adding should allow to fix potential issues, with a combination of a per-device mutex and dev->reg_state awareness. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com> Link: https://patch.msgid.link/20250114205531.967841-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: reduce RTNL hold duration in unregister_netdevice_many_notify() (part 1)Eric Dumazet
Two synchronize_net() calls are currently done while holding RTNL. This is source of RTNL contention in workloads adding and deleting many network namespaces per second, because synchronize_rcu() and synchronize_rcu_expedited() can use 60+ ms in some cases. For cleanup_net() use, temporarily release RTNL while calling the last synchronize_net(). This should be safe, because devices are no longer visible to other threads at this point. In any case, the new netdev_lock() / netdev_unlock() infrastructure that we are adding should allow to fix potential issues, with a combination of a per-device mutex and dev->reg_state awareness. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com> Link: https://patch.msgid.link/20250114205531.967841-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: no longer hold RTNL while calling flush_all_backlogs()Eric Dumazet
flush_all_backlogs() is called from unregister_netdevice_many_notify() as part of netdevice dismantles. This is currently called under RTNL, and can last up to 50 ms on busy hosts. There is no reason to hold RTNL at this stage, if our caller is cleanup_net() : netns are no more visible, devices are in NETREG_UNREGISTERING state and no other thread could mess our state while RTNL is temporarily released. In order to provide isolation, this patch provides a separate 'net_todo_list' for cleanup_net(). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com> Link: https://patch.msgid.link/20250114205531.967841-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: no longer assume RTNL is held in flush_all_backlogs()Eric Dumazet
flush_all_backlogs() uses per-cpu and static data to hold its temporary data, on the assumption it is called under RTNL protection. Following patch in the series will break this assumption. Use instead a dynamically allocated piece of memory. In the unlikely case the allocation fails, use a boot-time allocated memory. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com> Link: https://patch.msgid.link/20250114205531.967841-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: expedite synchronize_net() for cleanup_net()Eric Dumazet
cleanup_net() is the single thread responsible for netns dismantles, and a serious bottleneck. Before we can get per-netns RTNL, make sure all synchronize_net() called from this thread are using rcu_synchronize_expedited(). v3: deal with CONFIG_NET_NS=n Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jesse Brandeburg <jbrandeburg@cloudflare.com> Link: https://patch.msgid.link/20250114205531.967841-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: protect napi->irq with netdev_lock()Jakub Kicinski
Take netdev_lock() in netif_napi_set_irq(). All NAPI "control fields" are now protected by that lock (most of the other ones are set during napi add/del). The napi_hash_node is fully protected by the hash spin lock, but close enough for the kdoc... 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/20250115035319.559603-10-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: protect threaded status of NAPI with netdev_lock()Jakub Kicinski
Now that NAPI instances can't come and go without holding netdev->lock we can trivially switch from rtnl_lock() to netdev_lock() for setting netdev->threaded via sysfs. Note that since we do not lock netdev_lock around sysfs calls in the core we don't have to "trylock" like we do with rtnl_lock. Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250115035319.559603-9-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: protect NAPI enablement with netdev_lock()Jakub Kicinski
Wrap napi_enable() / napi_disable() with netdev_lock(). Provide the "already locked" flavor of the API. iavf needs the usual adjustment. A number of drivers call napi_enable() under a spin lock, so they have to be modified to take netdev_lock() first, then spin lock then call napi_enable_locked(). Protecting napi_enable() implies that napi->napi_id is protected by netdev_lock(). Acked-by: Francois Romieu <romieu@fr.zoreil.com> # via-velocity Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250115035319.559603-7-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: protect netdev->napi_list with netdev_lock()Jakub Kicinski
Hold netdev->lock when NAPIs are getting added or removed. This will allow safe access to NAPI instances of a net_device without rtnl_lock. Create a family of helpers which assume the lock is already taken. Switch iavf to them, as it makes extensive use of netdev->lock, already. 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/20250115035319.559603-6-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>
2025-01-15net: make netdev_lock() protect netdev->reg_stateJakub Kicinski
Protect writes to netdev->reg_state with netdev_lock(). From now on holding netdev_lock() is sufficient to prevent the net_device from getting unregistered, so code which wants to hold just a single netdev around no longer needs to hold rtnl_lock. We do not protect the NETREG_UNREGISTERED -> NETREG_RELEASED transition. We'd need to move mutex_destroy(netdev->lock) to .release, but the real reason is that trying to stop the unregistration process mid-way would be unsafe / crazy. Taking references on such devices is not safe, either. So the intended semantics are to lock REGISTERED devices. 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/20250115035319.559603-3-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: disallow setup single buffer XDP when tcp-data-split is enabled.Taehee Yoo
When a single buffer XDP is attached, NIC should guarantee only single page packets will be received. tcp-data-split feature splits packets into header and payload. single buffer XDP can't handle it properly. So attaching single buffer XDP should be disallowed when tcp-data-split is enabled. Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Taehee Yoo <ap420073@gmail.com> Link: https://patch.msgid.link/20250114142852.3364986-6-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-15net: ethtool: add hds_config member in ethtool_netdev_stateTaehee Yoo
When tcp-data-split is UNKNOWN mode, drivers arbitrarily handle it. For example, bnxt_en driver automatically enables if at least one of LRO/GRO/JUMBO is enabled. If tcp-data-split is UNKNOWN and LRO is enabled, a driver returns ENABLES of tcp-data-split, not UNKNOWN. So, `ethtool -g eth0` shows tcp-data-split is enabled. The problem is in the setting situation. In the ethnl_set_rings(), it first calls get_ringparam() to get the current driver's config. At that moment, if driver's tcp-data-split config is UNKNOWN, it returns ENABLE if LRO/GRO/JUMBO is enabled. Then, it sets values from the user and driver's current config to kernel_ethtool_ringparam. Last it calls .set_ringparam(). The driver, especially bnxt_en driver receives ETHTOOL_TCP_DATA_SPLIT_ENABLED. But it can't distinguish whether it is set by the user or just the current config. When user updates ring parameter, the new hds_config value is updated and current hds_config value is stored to old_hdsconfig. Driver's .set_ringparam() callback can distinguish a passed tcp-data-split value is came from user explicitly. If .set_ringparam() is failed, hds_config is rollbacked immediately. Suggested-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Taehee Yoo <ap420073@gmail.com> Link: https://patch.msgid.link/20250114142852.3364986-2-ap420073@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-13net: cleanup init_dummy_netdev_core()Jakub Kicinski
init_dummy_netdev_core() used to cater to net_devices which did not come from alloc_netdev_mqs(). Since that's no longer supported remove the init logic which duplicates alloc_netdev_mqs(). While at it rename back to init_dummy_netdev(). Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250113003456.3904110-2-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-13net: remove init_dummy_netdev()Jakub Kicinski
init_dummy_netdev() can initialize statically declared or embedded net_devices. Such netdevs did not come from alloc_netdev_mqs(). After recent work by Breno, there are the only two cases where we have do that. Switch those cases to alloc_netdev_mqs() and delete init_dummy_netdev(). Dealing with static netdevs is not worth the maintenance burden. Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20250113003456.3904110-1-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>
2025-01-09net: make sure we retain NAPI ordering on netdev->napi_listJakub Kicinski
Netlink code depends on NAPI instances being sorted by ID on the netdev list for dump continuation. We need to be able to find the position on the list where we left off if dump does not fit in a single skb, and in the meantime NAPI instances can come and go. This was trivially true when we were assigning a new ID to every new NAPI instance. Since we added the NAPI config API, we try to retain the ID previously used for the same queue, but still add the new NAPI instance at the start of the list. This is fine if we reset the entire netdev and all NAPIs get removed and added back. If driver replaces a NAPI instance during an operation like DEVMEM queue reset, or recreates a subset of NAPI instances in other ways we may end up with broken ordering, and therefore Netlink dumps with either missing or duplicated entries. At this stage the problem is theoretical. Only two drivers support queue API, bnxt and gve. gve recreates NAPIs during queue reset, but it doesn't support NAPI config. bnxt supports NAPI config but doesn't recreate instances during reset. We need to save the ID in the config as soon as it is assigned because otherwise the new NAPI will not know what ID it will get at enable time, at the time it is being added. Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-01-09net: no longer reset transport_header in __netif_receive_skb_core()Eric Dumazet
In commit 66e4c8d95008 ("net: warn if transport header was not set") I added a debug check in skb_transport_header() to detect if a caller expects the transport_header to be set to a meaningful value by a prior code path. Unfortunately, __netif_receive_skb_core() resets the transport header to the same value than the network header, defeating this check in receive paths. Pretending the transport and network headers are the same is usually wrong. This patch removes this reset for CONFIG_DEBUG_NET=y builds to let fuzzers and CI find bugs. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250107144342.499759-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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>
2025-01-07net: Hold rtnl_net_lock() in (un)?register_netdevice_notifier_dev_net().Kuniyuki Iwashima
(un)?register_netdevice_notifier_dev_net() hold RTNL before triggering the notifier for all netdev in the netns. Let's convert the RTNL to rtnl_net_lock(). Note that move_netdevice_notifiers_dev_net() is assumed to be (but not yet) protected by per-netns RTNL of both src and dst netns; we need to convert wireless and hyperv drivers that call dev_change_net_namespace(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250106070751.63146-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-07net: Hold rtnl_net_lock() in (un)?register_netdevice_notifier_net().Kuniyuki Iwashima
(un)?register_netdevice_notifier_net() hold RTNL before triggering the notifier for all netdev in the netns. Let's convert the RTNL to rtnl_net_lock(). Note that the per-netns netdev notifier is protected by per-netns RTNL. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250106070751.63146-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-07net: Hold __rtnl_net_lock() in (un)?register_netdevice_notifier().Kuniyuki Iwashima
(un)?register_netdevice_notifier() hold pernet_ops_rwsem and RTNL, iterate all netns, and trigger the notifier for all netdev. Let's hold __rtnl_net_lock() before triggering the notifier. Note that we will need protection for netdev_chain when RTNL is removed. (e.g. blocking_notifier conversion [0] with a lockdep annotation [1]) Link: https://lore.kernel.org/netdev/20250104063735.36945-2-kuniyu@amazon.com/ [0] Link: https://lore.kernel.org/netdev/20250105075957.67334-1-kuniyu@amazon.com/ [1] Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250106070751.63146-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-07net: watchdog: rename __dev_watchdog_up() and dev_watchdog_down()Eric Dumazet
In commit d7811e623dd4 ("[NET]: Drop tx lock in dev_watchdog_up") dev_watchdog_up() became a simple wrapper for __netdev_watchdog_up() Herbert also said : "In 2.6.19 we can eliminate the unnecessary __dev_watchdog_up and replace it with dev_watchdog_up." This patch consolidates things to have only two functions, with a common prefix. - netdev_watchdog_up(), exported for the sake of one freescale driver. This replaces __netdev_watchdog_up() and dev_watchdog_up(). - netdev_watchdog_down(), static to net/sched/sch_generic.c This replaces dev_watchdog_down(). Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20250105090924.1661822-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-07dev: Hold per-netns RTNL in (un)?register_netdev().Kuniyuki Iwashima
Let's hold per-netns RTNL of dev_net(dev) in register_netdev() and unregister_netdev(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-01-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.13-rc6). No conflicts. Adjacent changes: include/linux/if_vlan.h f91a5b808938 ("af_packet: fix vlan_get_protocol_dgram() vs MSG_PEEK") 3f330db30638 ("net: reformat kdoc return statements") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-01-02net: reenable NETIF_F_IPV6_CSUM offload for BIG TCP packetsWillem de Bruijn
The blamed commit disabled hardware offoad of IPv6 packets with extension headers on devices that advertise NETIF_F_IPV6_CSUM, based on the definition of that feature in skbuff.h: * * - %NETIF_F_IPV6_CSUM * - Driver (device) is only able to checksum plain * TCP or UDP packets over IPv6. These are specifically * unencapsulated packets of the form IPv6|TCP or * IPv6|UDP where the Next Header field in the IPv6 * header is either TCP or UDP. IPv6 extension headers * are not supported with this feature. This feature * cannot be set in features for a device with * NETIF_F_HW_CSUM also set. This feature is being * DEPRECATED (see below). The change causes skb_warn_bad_offload to fire for BIG TCP packets. [ 496.310233] WARNING: CPU: 13 PID: 23472 at net/core/dev.c:3129 skb_warn_bad_offload+0xc4/0xe0 [ 496.310297] ? skb_warn_bad_offload+0xc4/0xe0 [ 496.310300] skb_checksum_help+0x129/0x1f0 [ 496.310303] skb_csum_hwoffload_help+0x150/0x1b0 [ 496.310306] validate_xmit_skb+0x159/0x270 [ 496.310309] validate_xmit_skb_list+0x41/0x70 [ 496.310312] sch_direct_xmit+0x5c/0x250 [ 496.310317] __qdisc_run+0x388/0x620 BIG TCP introduced an IPV6_TLV_JUMBO IPv6 extension header to communicate packet length, as this is an IPv6 jumbogram. But, the feature is only enabled on devices that support BIG TCP TSO. The header is only present for PF_PACKET taps like tcpdump, and not transmitted by physical devices. For this specific case of extension headers that are not transmitted, return to the situation before the blamed commit and support hardware offload. ipv6_has_hopopt_jumbo() tests not only whether this header is present, but also that it is the only extension header before a terminal (L4) header. Fixes: 04c20a9356f2 ("net: skip offload for NETIF_F_IPV6_CSUM if ipv6 header contains extension") Reported-by: syzbot <syzkaller@googlegroups.com> Reported-by: Eric Dumazet <edumazet@google.com> Closes: https://lore.kernel.org/netdev/CANn89iK1hdC3Nt8KPhOtTF8vCPc1AHDCtse_BTNki1pWxAByTQ@mail.gmail.com/ Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250101164909.1331680-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-05xdp: register system page pool as an XDP memory modelToke Høiland-Jørgensen
To make the system page pool usable as a source for allocating XDP frames, we need to register it with xdp_reg_mem_model(), so that page return works correctly. This is done in preparation for using the system page_pool to convert XDP_PASS XSk frames to skbs; for the same reason, make the per-cpu variable non-static so we can access it from other source files as well (but w/o exporting). Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Link: https://patch.msgid.link/20241203173733.3181246-7-aleksander.lobakin@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>