summaryrefslogtreecommitdiff
path: root/net/core/dev.c
AgeCommit message (Collapse)AuthorFilesLines
2026-03-30net: use skb_header_pointer() for TCPv4 GSO frag_off checkGuoyu Su1-3/+8
Syzbot reported a KMSAN uninit-value warning in gso_features_check() called from netif_skb_features() [1]. gso_features_check() reads iph->frag_off to decide whether to clear mangleid_features. Accessing the IPv4 header via ip_hdr()/inner_ip_hdr() can rely on skb header offsets that are not always safe for direct dereference on packets injected from PF_PACKET paths. Use skb_header_pointer() for the TCPv4 frag_off check so the header read is robust whether data is already linear or needs copying. [1] https://syzkaller.appspot.com/bug?extid=1543a7d954d9c6d00407 Link: https://lore.kernel.org/netdev/willemdebruijn.kernel.1a9f35039caab@gmail.com/ Fixes: cbc53e08a793 ("GSO: Add GSO type for fixed IPv4 ID") Reported-by: syzbot+1543a7d954d9c6d00407@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1543a7d954d9c6d00407 Tested-by: syzbot+1543a7d954d9c6d00407@syzkaller.appspotmail.com Signed-off-by: Guoyu Su <yss2813483011xxl@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260327153507.39742-1-yss2813483011xxl@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-24net: correctly handle tunneled traffic on IPV6_CSUM GSO fallbackWillem de Bruijn1-5/+17
NETIF_F_IPV6_CSUM only advertises support for checksum offload of packets without IPv6 extension headers. Packets with extension headers must fall back onto software checksumming. Since TSO depends on checksum offload, those must revert to GSO. The below commit introduces that fallback. It always checks network header length. For tunneled packets, the inner header length must be checked instead. Extend the check accordingly. A special case is tunneled packets without inner IP protocol. Such as RFC 6951 SCTP in UDP. Those are not standard IPv6 followed by transport header either, so also must revert to the software GSO path. Cc: stable@vger.kernel.org Fixes: 864e3396976e ("net: gso: Forbid IPv6 TSO with extensions on devices with only IPV6_CSUM") Reported-by: Tangxin Xie <xietangxin@yeah.net> Closes: https://lore.kernel.org/netdev/0414e7e2-9a1c-4d7c-a99d-b9039cf68f40@yeah.net/ Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260320190148.2409107-1-willemdebruijn.kernel@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-05net: Provide a PREEMPT_RT specific check for netdev_queue::_xmit_lockSebastian Andrzej Siewior1-4/+1
After acquiring netdev_queue::_xmit_lock the number of the CPU owning the lock is recorded in netdev_queue::xmit_lock_owner. This works as long as the BH context is not preemptible. On PREEMPT_RT the softirq context is preemptible and without the softirq-lock it is possible to have multiple user in __dev_queue_xmit() submitting a skb on the same CPU. This is fine in general but this means also that the current CPU is recorded as netdev_queue::xmit_lock_owner. This in turn leads to the recursion alert and the skb is dropped. Instead checking the for CPU number, that owns the lock, PREEMPT_RT can check if the lockowner matches the current task. Add netif_tx_owned() which returns true if the current context owns the lock by comparing the provided CPU number with the recorded number. This resembles the current check by negating the condition (the current check returns true if the lock is not owned). On PREEMPT_RT use rt_mutex_owner() to return the lock owner and compare the current task against it. Use the new helper in __dev_queue_xmit() and netif_local_xmit_active() which provides a similar check. Update comments regarding pairing READ_ONCE(). Reported-by: Bert Karwatzki <spasswolf@web.de> Closes: https://lore.kernel.org/all/20260216134333.412332-1-spasswolf@web.de Fixes: 3253cb49cbad4 ("softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reported-by: Bert Karwatzki <spasswolf@web.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20260302162631.uGUyIqDT@linutronix.de Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-04net: devmem: use READ_ONCE/WRITE_ONCE on binding->devBobby Eshleman1-1/+1
binding->dev is protected on the write-side in mp_dmabuf_devmem_uninstall() against concurrent writes, but due to the concurrent bare reads in net_devmem_get_binding() and validate_xmit_unreadable_skb() it should be wrapped in a READ_ONCE/WRITE_ONCE pair to make sure no compiler optimizations play with the underlying register in unforeseen ways. Doesn't present a critical bug because the known compiler optimizations don't result in bad behavior. There is no tearing on u64, and load omissions/invented loads would only break if additional binding->dev references were inlined together (they aren't right now). This just more strictly follows the linux memory model (i.e., "Lock-Protected Writes With Lockless Reads" in tools/memory-model/Documentation/access-marking.txt). Fixes: bd61848900bf ("net: devmem: Implement TX path") Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com> Link: https://patch.msgid.link/20260302-devmem-membar-fix-v2-1-5b33c9cbc28b@meta.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-03net: Fix rcu_tasks stall in threaded busypollYiFei Zhu1-6/+11
I was debugging a NIC driver when I noticed that when I enable threaded busypoll, bpftrace hangs when starting up. dmesg showed: rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 10658 jiffies old. rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 40793 jiffies old. rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 131273 jiffies old. rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 402058 jiffies old. INFO: rcu_tasks detected stalls on tasks: 00000000769f52cd: .N nvcsw: 2/2 holdout: 1 idle_cpu: -1/64 task:napi/eth2-8265 state:R running task stack:0 pid:48300 tgid:48300 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: <TASK> ? napi_threaded_poll_loop+0x27c/0x2c0 ? __pfx_napi_threaded_poll+0x10/0x10 ? napi_threaded_poll+0x26/0x80 ? kthread+0xfa/0x240 ? __pfx_kthread+0x10/0x10 ? ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ? ret_from_fork_asm+0x1a/0x30 </TASK> The cause is that in threaded busypoll, the main loop is in napi_threaded_poll rather than napi_threaded_poll_loop, where the latter rarely iterates more than once within its loop. For rcu_softirq_qs_periodic inside napi_threaded_poll_loop to report its qs state, the last_qs must be 100ms behind, and this can't happen because napi_threaded_poll_loop rarely iterates in threaded busypoll, and each time napi_threaded_poll_loop is called last_qs is reset to latest jiffies. This patch changes so that in threaded busypoll, last_qs is saved in the outer napi_threaded_poll, and whether busy_poll_last_qs is NULL indicates whether napi_threaded_poll_loop is called for busypoll. This way last_qs would not reset to latest jiffies on each invocation of napi_threaded_poll_loop. Fixes: c18d4b190a46 ("net: Extend NAPI threaded polling to allow kthread based busy polling") Cc: stable@vger.kernel.org Signed-off-by: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Samiullah Khawaja <skhawaja@google.com> Link: https://patch.msgid.link/20260227221937.1060857-1-zhuyifei@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-26Merge tag 'net-7.0-rc2' of ↵Linus Torvalds1-12/+23
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from IPsec, Bluetooth and netfilter Current release - regressions: - wifi: fix dev_alloc_name() return value check - rds: fix recursive lock in rds_tcp_conn_slots_available Current release - new code bugs: - vsock: lock down child_ns_mode as write-once Previous releases - regressions: - core: - do not pass flow_id to set_rps_cpu() - consume xmit errors of GSO frames - netconsole: avoid OOB reads, msg is not nul-terminated - netfilter: h323: fix OOB read in decode_choice() - tcp: re-enable acceptance of FIN packets when RWIN is 0 - udplite: fix null-ptr-deref in __udp_enqueue_schedule_skb(). - wifi: brcmfmac: fix potential kernel oops when probe fails - phy: register phy led_triggers during probe to avoid AB-BA deadlock - eth: - bnxt_en: fix deleting of Ntuple filters - wan: farsync: fix use-after-free bugs caused by unfinished tasklets - xscale: check for PTP support properly Previous releases - always broken: - tcp: fix potential race in tcp_v6_syn_recv_sock() - kcm: fix zero-frag skb in frag_list on partial sendmsg error - xfrm: - fix race condition in espintcp_close() - always flush state and policy upon NETDEV_UNREGISTER event - bluetooth: - purge error queues in socket destructors - fix response to L2CAP_ECRED_CONN_REQ - eth: - mlx5: - fix circular locking dependency in dump - fix "scheduling while atomic" in IPsec MAC address query - gve: fix incorrect buffer cleanup for QPL - team: avoid NETDEV_CHANGEMTU event when unregistering slave - usb: validate USB endpoints" * tag 'net-7.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits) netfilter: nf_conntrack_h323: fix OOB read in decode_choice() dpaa2-switch: validate num_ifs to prevent out-of-bounds write net: consume xmit errors of GSO frames vsock: document write-once behavior of the child_ns_mode sysctl vsock: lock down child_ns_mode as write-once selftests/vsock: change tests to respect write-once child ns mode net/mlx5e: Fix "scheduling while atomic" in IPsec MAC address query net/mlx5: Fix missing devlink lock in SRIOV enable error path net/mlx5: E-switch, Clear legacy flag when moving to switchdev net/mlx5: LAG, disable MPESW in lag_disable_change() net/mlx5: DR, Fix circular locking dependency in dump selftests: team: Add a reference count leak test team: avoid NETDEV_CHANGEMTU event when unregistering slave net: mana: Fix double destroy_workqueue on service rescan PCI path MAINTAINERS: Update maintainer entry for QUALCOMM ETHQOS ETHERNET DRIVER dpll: zl3073x: Remove redundant cleanup in devm_dpll_init() selftests/net: packetdrill: Verify acceptance of FIN packets when RWIN is 0 tcp: re-enable acceptance of FIN packets when RWIN is 0 vsock: Use container_of() to get net namespace in sysctl handlers net: usb: kaweth: validate USB endpoints ...
2026-02-26net: consume xmit errors of GSO framesJakub Kicinski1-5/+18
udpgro_frglist.sh and udpgro_bench.sh are the flakiest tests currently in NIPA. They fail in the same exact way, TCP GRO test stalls occasionally and the test gets killed after 10min. These tests use veth to simulate GRO. They attach a trivial ("return XDP_PASS;") XDP program to the veth to force TSO off and NAPI on. Digging into the failure mode we can see that the connection is completely stuck after a burst of drops. The sender's snd_nxt is at sequence number N [1], but the receiver claims to have received (rcv_nxt) up to N + 3 * MSS [2]. Last piece of the puzzle is that senders rtx queue is not empty (let's say the block in the rtx queue is at sequence number N - 4 * MSS [3]). In this state, sender sends a retransmission from the rtx queue with a single segment, and sequence numbers N-4*MSS:N-3*MSS [3]. Receiver sees it and responds with an ACK all the way up to N + 3 * MSS [2]. But sender will reject this ack as TCP_ACK_UNSENT_DATA because it has no recollection of ever sending data that far out [1]. And we are stuck. The root cause is the mess of the xmit return codes. veth returns an error when it can't xmit a frame. We end up with a loss event like this: ------------------------------------------------- | GSO super frame 1 | GSO super frame 2 | |-----------------------------------------------| | seg | seg | seg | seg | seg | seg | seg | seg | | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | ------------------------------------------------- x ok ok <ok>| ok ok ok <x> \\ snd_nxt "x" means packet lost by veth, and "ok" means it went thru. Since veth has TSO disabled in this test it sees individual segments. Segment 1 is on the retransmit queue and will be resent. So why did the sender not advance snd_nxt even tho it clearly did send up to seg 8? tcp_write_xmit() interprets the return code from the core to mean that data has not been sent at all. Since TCP deals with GSO super frames, not individual segment the crux of the problem is that loss of a single segment can be interpreted as loss of all. TCP only sees the last return code for the last segment of the GSO frame (in <> brackets in the diagram above). Of course for the problem to occur we need a setup or a device without a Qdisc. Otherwise Qdisc layer disconnects the protocol layer from the device errors completely. We have multiple ways to fix this. 1) make veth not return an error when it lost a packet. While this is what I think we did in the past, the issue keeps reappearing and it's annoying to debug. The game of whack a mole is not great. 2) fix the damn return codes We only talk about NETDEV_TX_OK and NETDEV_TX_BUSY in the documentation, so maybe we should make the return code from ndo_start_xmit() a boolean. I like that the most, but perhaps some ancient, not-really-networking protocol would suffer. 3) make TCP ignore the errors It is not entirely clear to me what benefit TCP gets from interpreting the result of ip_queue_xmit()? Specifically once the connection is established and we're pushing data - packet loss is just packet loss? 4) this fix Ignore the rc in the Qdisc-less+GSO case, since it's unreliable. We already always return OK in the TCQ_F_CAN_BYPASS case. In the Qdisc-less case let's be a bit more conservative and only mask the GSO errors. This path is taken by non-IP-"networks" like CAN, MCTP etc, so we could regress some ancient thing. This is the simplest, but also maybe the hackiest fix? Similar fix has been proposed by Eric in the past but never committed because original reporter was working with an OOT driver and wasn't providing feedback (see Link). Link: https://lore.kernel.org/CANn89iJcLepEin7EtBETrZ36bjoD9LrR=k4cfwWh046GB+4f9A@mail.gmail.com Fixes: 1f59533f9ca5 ("qdisc: validate frames going through the direct_xmit path") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260223235100.108939-1-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-23net: do not pass flow_id to set_rps_cpu()Eric Dumazet1-7/+5
Blamed commit made the assumption that the RPS table for each receive queue would have the same size, and that it would not change. Compute flow_id in set_rps_cpu(), do not assume we can use the value computed by get_rps_cpu(). Otherwise we risk out-of-bound access and/or crashes. Fixes: 48aa30443e52 ("net: Cache hash and flow_id to avoid recalculation") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Krishna Kumar <krikku@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260220222605.3468081-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-21Convert more 'alloc_obj' cases to default GFP_KERNEL argumentsLinus Torvalds1-2/+1
This converts some of the visually simpler cases that have been split over multiple lines. I only did the ones that are easy to verify the resulting diff by having just that final GFP_KERNEL argument on the next line. Somebody should probably do a proper coccinelle script for this, but for me the trivial script actually resulted in an assertion failure in the middle of the script. I probably had made it a bit _too_ trivial. So after fighting that far a while I decided to just do some of the syntactically simpler cases with variations of the previous 'sed' scripts. The more syntactically complex multi-line cases would mostly really want whitespace cleanup anyway. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_flex' family to use the new default GFP_KERNEL argumentLinus Torvalds1-1/+1
This is the exact same thing as the 'alloc_obj()' version, only much smaller because there are a lot fewer users of the *alloc_flex() interface. As with alloc_obj() version, this was done entirely with mindless brute force, using the same script, except using 'flex' in the pattern rather than 'objs*'. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds1-4/+4
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook1-13/+12
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-17net: remove WARN_ON_ONCE when accessing forward path arrayPablo Neira Ayuso1-1/+1
Although unlikely, recent support for IPIP tunnels increases chances of reaching this WARN_ON_ONCE if userspace manages to build a sufficiently long forward path. Remove it. Fixes: ddb94eafab8b ("net: resolve forwarding path from virtual netdevice and HW destination address") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-02-17net: fix backlog_unlock_irq_restore() vs CONFIG_PREEMPT_RTEric Dumazet1-5/+12
CONFIG_PREEMPT_RT is special, make this clear in backlog_lock_irq_save() and backlog_unlock_irq_restore(). The issue shows up with CONFIG_DEBUG_IRQFLAGS=y raw_local_irq_restore() called with IRQs enabled WARNING: kernel/locking/irqflag-debug.c:10 at warn_bogus_irq_restore+0xc/0x20 kernel/locking/irqflag-debug.c:10, CPU#1: aoe_tx0/1321 Modules linked in: CPU: 1 UID: 0 PID: 1321 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:warn_bogus_irq_restore+0xc/0x20 kernel/locking/irqflag-debug.c:10 Call Trace: <TASK> backlog_unlock_irq_restore net/core/dev.c:253 [inline] enqueue_to_backlog+0x525/0xcf0 net/core/dev.c:5347 netif_rx_internal+0x120/0x550 net/core/dev.c:5659 __netif_rx+0xa9/0x110 net/core/dev.c:5679 loopback_xmit+0x43a/0x660 drivers/net/loopback.c:90 __netdev_start_xmit include/linux/netdevice.h:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2df/0x830 net/core/dev.c:3880 __dev_queue_xmit+0x16f4/0x3990 net/core/dev.c:4829 dev_queue_xmit include/linux/netdevice.h:3384 [inline] Fixes: 27a01c1969a5 ("net: fully inline backlog_unlock_irq_restore()") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260213120427.2914544-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-06net/ipv6: Remove jumbo_remove step from TX pathAlice Mikityanska1-4/+2
Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove unnecessary steps from the GSO TX path, that used to check and remove HBH. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260205133925.526371-5-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-23net: use netdev_queue_config() for mp restartJakub Kicinski1-17/+0
We should follow the prepare/commit approach for queue configuration. The qcfg struct should be added to dev->cfg rather than directly to queue objects so that we can clone and discard the pending config easily. Remove the qcfg in struct netdev_rx_queue, and switch remaining callers to netdev_queue_config(). netdev_queue_config() will construct the qcfg on the fly based on device defaults and state of the queue. ndo_default_qcfg becomes optional because having the callback itself does not have any meaningful semantics to us. Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com> Link: https://patch.msgid.link/20260122005113.2476634-5-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-23net: introduce mangleid_featuresPaolo Abeni1-1/+4
Some/most devices implementing gso_partial need to disable the GSO partial features when the IP ID can't be mangled; to that extend each of them implements something alike the following[1]: if (skb->encapsulation && !(features & NETIF_F_TSO_MANGLEID)) features &= ~NETIF_F_TSO; in the ndo_features_check() op, which leads to a bit of duplicate code. Later patch in the series will implement GSO partial support for virtual devices, and the current status quo will require more duplicate code and a new indirect call in the TX path for them. Introduce the mangleid_features mask, allowing the core to disable NIC features based on/requiring MANGLEID, without any further intervention from the driver. The same functionality could be alternatively implemented adding a single boolean flag to the struct net_device, but would require an additional checks in ndo_features_check(). Also note that [1] is incorrect if the NIC additionally implements NETIF_F_GSO_UDP_L4, mangleid_features transparently handle even such a case. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/5a7cdaeea40b0a29b88e525b6c942d73ed3b8ce7.1769011015.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-20Merge tag 'net-queue-rx-buf-len-v9' of https://github.com/isilence/linuxJakub Kicinski1-0/+17
Pavel Begunkov says: ==================== Add support for providers with large rx buffer Many modern NICs support configurable receive buffer lengths, and zcrx and memory providers can use buffers larger than 4K to improve performance. When paired with hw-gro larger rx buffer sizes can drastically reduce the number of buffers traversing the stack and save a lot of processing time. It also allows to give to users larger contiguous chunks of data. Single stream benchmarks showed up to ~30% CPU util improvement. E.g. comparison for 4K vs 32K buffers using a 200Gbit NIC: packets=23987040 (MB=2745098), rps=199559 (MB/s=22837) CPU %usr %nice %sys %iowait %irq %soft %idle 0 1.53 0.00 27.78 2.72 1.31 66.45 0.22 packets=24078368 (MB=2755550), rps=200319 (MB/s=22924) CPU %usr %nice %sys %iowait %irq %soft %idle 0 0.69 0.00 8.26 31.65 1.83 57.00 0.57 This series adds net infrastructure for memory providers configuring the size and implements it for bnxt. It's an opt-in feature for drivers, they should advertise support for the parameter in the qops and must check if the hardware supports the given size. It's limited to memory providers as it drastically simplifies implementation. It doesn't affect the fast path zcrx uAPI, and the user exposed parameter is defined in zcrx terms, which allows it to be flexible and adjusted in the future. A liburing example can be found at [2] full branch: [1] https://github.com/isilence/linux.git zcrx/large-buffers-v8 Liburing example: [2] https://github.com/isilence/liburing.git zcrx/rx-buf-len * tag 'net-queue-rx-buf-len-v9' of https://github.com/isilence/linux: io_uring/zcrx: document area chunking parameter selftests: iou-zcrx: test large chunk sizes eth: bnxt: support qcfg provided rx page size eth: bnxt: adjust the fill level of agg queues with larger buffers eth: bnxt: store rx buffer size per queue net: pass queue rx page size from memory provider net: add bare bone queue configs net: reduce indent of struct netdev_queue_mgmt_ops members net: memzero mp params when closing a queue ==================== Link: https://patch.msgid.link/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-20Revert "Merge branch 'netkit-support-for-io_uring-zero-copy-and-af_xdp'"Jakub Kicinski1-7/+0
This reverts commit 77b9c4a438fc66e2ab004c411056b3fb71a54f2c, reversing changes made to 4515ec4ad58a37e70a9e1256c0b993958c9b7497: 931420a2fc36 ("selftests/net: Add netkit container tests") ab771c938d9a ("selftests/net: Make NetDrvContEnv support queue leasing") 6be87fbb2776 ("selftests/net: Add env for container based tests") 61d99ce3dfc2 ("selftests/net: Add bpf skb forwarding program") 920da3634194 ("netkit: Add xsk support for af_xdp applications") eef51113f8af ("netkit: Add netkit notifier to check for unregistering devices") b5ef109d22d4 ("netkit: Implement rtnl_link_ops->alloc and ndo_queue_create") b5c3fa4a0b16 ("netkit: Add single device mode for netkit") 0073d2fd679d ("xsk: Proxy pool management for leased queues") 1ecea95dd3b5 ("xsk: Extend xsk_rcv_check validation") 804bf334d08a ("net: Proxy netdev_queue_get_dma_dev for leased queues") 0caa9a8ddec3 ("net: Proxy net_mp_{open,close}_rxq for leased queues") ff8889ff9107 ("net, ethtool: Disallow leased real rxqs to be resized") 9e2103f36110 ("net: Add lease info to queue-get response") 31127deddef4 ("net: Implement netdev_nl_queue_create_doit") a5546e18f77c ("net: Add queue-create operation") The series will conflict with io_uring work, and the code needs more polish. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-20net: Implement netdev_nl_queue_create_doitDaniel Borkmann1-0/+7
Implement netdev_nl_queue_create_doit which creates a new rx queue in a virtual netdev and then leases it to a rx queue in a physical netdev. Example with ynl client: # ./pyynl/cli.py \ --spec ~/netlink/specs/netdev.yaml \ --do queue-create \ --json '{"ifindex": 8, "type": "rx", "lease": {"ifindex": 4, "queue": {"type": "rx", "id": 15}}}' {'id': 1} Note that the netdevice locking order is always from the virtual to the physical device. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Co-developed-by: David Wei <dw@davidwei.uk> Signed-off-by: David Wei <dw@davidwei.uk> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260115082603.219152-3-daniel@iogearbox.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-9/+22
Cross-merge networking fixes after downstream PR (net-6.19-rc6). No conflicts, or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-14net: add bare bone queue configsPavel Begunkov1-0/+17
We'll need to pass extra parameters when allocating a queue for memory providers. Define a new structure for queue configurations, and pass it to qapi callbacks. It's empty for now, actual parameters will be added in following patches. Configurations should persist across resets, and for that they're default-initialised on device registration and stored in struct netdev_rx_queue. We also add a new qapi callback for defaulting a given config. It must be implemented if a driver wants to use queue configs and is optional otherwise. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
2026-01-13net: add net.core.qdisc_max_burstEric Dumazet1-3/+3
In blamed commit, I added a check against the temporary queue built in __dev_xmit_skb(). Idea was to drop packets early, before any spinlock was acquired. if (unlikely(defer_count > READ_ONCE(q->limit))) { kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP); return NET_XMIT_DROP; } It turned out that HTB Qdisc has a zero q->limit. HTB limits packets on a per-class basis. Some of our tests became flaky. Add a new sysctl : net.core.qdisc_max_burst to control how many packets can be stored in the temporary lockless queue. Also add a new QDISC_BURST_DROP drop reason to better diagnose future issues. Thanks Neal ! Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption") Reported-and-bisected-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20260107104159.3669285-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-01-09net: update netdev_lock_{type,name}Eric Dumazet1-6/+19
Add missing entries in netdev_lock_type[] and netdev_lock_name[] : CAN, MCTP, RAWIP, CAIF, IP6GRE, 6LOWPAN, NETLINK, VSOCKMON, IEEE802154_MONITOR. Also add a WARN_ONCE() in netdev_lock_pos() to help future bug hunting next time a protocol is added without updating these arrays. Fixes: 1a33e10e4a95 ("net: partially revert dynamic lockdep key changes") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260108093244.830280-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-06net: fully inline backlog_unlock_irq_restore()Eric Dumazet1-7/+6
Some arches (like x86) do not inline spin_unlock_irqrestore(). backlog_unlock_irq_restore() is in RPS/RFS critical path, we prefer using spin_unlock() + local_irq_restore() for optimal performance. Also change backlog_unlock_irq_restore() second argument to avoid a pointless dereference. No difference in net/core/dev.o code size. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260105163054.13698-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-12-28net: avoid prefetching NULL pointersEric Dumazet1-3/+5
Aditya Gupta reported PowerPC crashes bisected to the blamed commit. Apparently some platforms do not allow prefetch() on arbitrary pointers. prefetch(next); prefetch(&next->priority); // CRASH when next == NULL Only NULL seems to be supported, with specific handling in prefetch(). Add a conditional to avoid the two prefetches and the skb->next clearing for the last skb in the list. Fixes: b2e9821cff6c ("net: prefech skb->priority in __dev_xmit_skb()") Reported-by: Aditya Gupta <adityag@linux.ibm.com> Closes: https://lore.kernel.org/netdev/e9f4abee-b132-440f-a50e-bced0868b5a7@linux.ibm.com/T/#mddc372b64ec5a3b181acc9ee3909110c391cc18a Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Aditya Gupta <adityag@linux.ibm.com> Link: https://patch.msgid.link/20251218081844.809008-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net_sched: add qdisc_dequeue_drop() helperEric Dumazet1-9/+13
Some qdisc like cake, codel, fq_codel might drop packets in their dequeue() method. This is currently problematic because dequeue() runs with the qdisc spinlock held. Freeing skbs can be extremely expensive. Add qdisc_dequeue_drop() method and a new TCQ_F_DEQUEUE_DROPS so that these qdiscs can opt-in to defer the skb frees after the socket spinlock is released. TCQ_F_DEQUEUE_DROPS is an attempt to not penalize other qdiscs with an extra cache line miss. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-14-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net_sched: add tcf_kfree_skb_list() helperEric Dumazet1-10/+5
Using kfree_skb_list_reason() to free list of skbs from qdisc operations seems wrong as each skb might have a different drop reason. Cleanup __dev_xmit_skb() to call tcf_kfree_skb_list() once in preparation of the following patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-13-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net: annotate a data-race in __dev_xmit_skb()Eric Dumazet1-1/+1
q->limit is read locklessly, add a READ_ONCE(). Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-12-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net: prefech skb->priority in __dev_xmit_skb()Eric Dumazet1-0/+1
Most qdiscs need to read skb->priority at enqueue time(). In commit 100dfa74cad9 ("net: dev_queue_xmit() llist adoption") I added a prefetch(next), lets add another one for the second half of skb. Note that skb->priority and skb->hash share a common cache line, so this patch helps qdiscs needing both fields. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-11-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net: use qdisc_pkt_len_segs_init() in sch_handle_ingress()Eric Dumazet1-1/+1
sch_handle_ingress() sets qdisc_skb_cb(skb)->pkt_len. We also need to initialize qdisc_skb_cb(skb)->pkt_segs. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-5-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net_sched: initialize qdisc_skb_cb(skb)->pkt_segs in qdisc_pkt_len_init()Eric Dumazet1-4/+11
qdisc_pkt_len_init() is currently initalizing qdisc_skb_cb(skb)->pkt_len. Add qdisc_skb_cb(skb)->pkt_segs initialization and rename this function to qdisc_pkt_len_segs_init(). Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-4-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net: init shinfo->gso_segs from qdisc_pkt_len_init()Eric Dumazet1-1/+2
Qdisc use shinfo->gso_segs for their pkts stats in bstats_update(), but this field needs to be initialized for SKB_GSO_DODGY users. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-3-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-25net_sched: make room for (struct qdisc_skb_cb)->pkt_segsEric Dumazet1-1/+1
Add a new u16 field, next to pkt_len : pkt_segs This will cache shinfo->gso_segs to speed up qdisc deqeue(). Move slave_dev_queue_mapping at the end of qdisc_skb_cb, and move three bits from tc_skb_cb : - post_ct - post_ct_snat - post_ct_dnat Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251121083256.674562-2-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-07net: add prefetch() in skb_defer_free_flush()Eric Dumazet1-0/+1
skb_defer_free_flush() is becoming more important these days. Add a prefetch operation to reduce latency a bit on some platforms like AMD EPYC 7B12. On more recent cpus, a stall happens when reading skb_shinfo(). Avoiding it will require a more elaborate strategy. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/20251106085500.2438951-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert struct sockaddr to fixed-size "sa_data[14]"Kees Cook1-1/+1
Revert struct sockaddr from flexible array to fixed 14-byte "sa_data", to solve over 36,000 -Wflex-array-member-not-at-end warnings, since struct sockaddr is embedded within many network structs. With socket/proto sockaddr-based internal APIs switched to use struct sockaddr_unsized, there should be no more uses of struct sockaddr that depend on reading beyond the end of struct sockaddr::sa_data that might trigger bounds checking. Comparing an x86_64 "allyesconfig" vmlinux build before and after this patch showed no new "ud1" instructions from CONFIG_UBSAN_BOUNDS nor any new "field-spanning" memcpy CONFIG_FORTIFY_SOURCE instrumentations. Cc: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-8-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: mark deliver_skb() as unlikely and not inlinedEric Dumazet1-11/+11
deliver_skb() should not be inlined as is it not called in the fast path. Add unlikely() clauses giving hints to the compiler about this fact. Before this patch: size net/core/dev.o text data bss dec hex filename 121794 13330 176 135300 21084 net/core/dev.o __netif_receive_skb_core() size on x86_64 : 4080 bytes. After: size net/core/dev.o text data bss dec hex filenamee 120330 13338 176 133844 20ad4 net/core/dev.o __netif_receive_skb_core() size on x86_64 : 2781 bytes. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251103165256.1712169-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-03net: Extend NAPI threaded polling to allow kthread based busy pollingSamiullah Khawaja1-10/+48
Add a new state NAPI_STATE_THREADED_BUSY_POLL to the NAPI state enum to enable and disable threaded busy polling. When threaded busy polling is enabled for a NAPI, enable NAPI_STATE_THREADED also. When the threaded NAPI is scheduled, set NAPI_STATE_IN_BUSY_POLL to signal napi_complete_done not to rearm interrupts. Whenever NAPI_STATE_THREADED_BUSY_POLL is unset, the NAPI_STATE_IN_BUSY_POLL will be unset, napi_complete_done unsets the NAPI_STATE_SCHED_THREADED bit also, which in turn will make the kthread go to sleep. Signed-off-by: Samiullah Khawaja <skhawaja@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Acked-by: Martin Karsten <mkarsten@uwaterloo.ca> Tested-by: Martin Karsten <mkarsten@uwaterloo.ca> Link: https://patch.msgid.link/20251028203007.575686-2-skhawaja@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-29ipv6: icmp: Add RFC 5837 supportIdo Schimmel1-0/+1
Add the ability to append the incoming IP interface information to ICMPv6 error messages in accordance with RFC 5837 and RFC 4884. This is required for more meaningful traceroute results in unnumbered networks. The feature is disabled by default and controlled via a new sysctl ("net.ipv6.icmp.errors_extension_mask") which accepts a bitmask of ICMP extensions to append to ICMP error messages. Currently, only a single value is supported, but the interface and the implementation should be able to support more extensions, if needed. Clone the skb and copy the relevant data portions before modifying the skb as the caller of icmp6_send() still owns the skb after the function returns. This should be fine since by default ICMP error messages are rate limited to 1000 per second and no more than 1 per second per specific host. Trim or pad the packet to 128 bytes before appending the ICMP extension structure in order to be compatible with legacy applications that assume that the ICMP extension structure always starts at this offset (the minimum length specified by RFC 4884). Since commit 20e1954fe238 ("ipv6: RFC 4884 partial support for SIT/GRE tunnels") it is possible for icmp6_send() to be called with an skb that already contains ICMP extensions. This can happen when we receive an ICMPv4 message with extensions from a tunnel and translate it to an ICMPv6 message towards an IPv6 host in the overlay network. I could not find an RFC that supports this behavior, but it makes sense to not overwrite the original extensions that were appended to the packet. Therefore, avoid appending extensions if the length field in the provided ICMPv6 header is already filled. Export netdev_copy_name() using EXPORT_IPV6_MOD_GPL() to make it available to IPv6 when it is built as a module. Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251027082232.232571-3-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-28net: optimize enqueue_to_backlog() for the fast pathEric Dumazet1-8/+10
Add likely() and unlikely() clauses for the common cases: Device is running. Queue is not full. Queue is less than half capacity. Add max_backlog parameter to skb_flow_limit() to avoid a second READ_ONCE(net_hotdata.max_backlog). skb_flow_limit() does not need the backlog_lock protection, and can be called before we acquire the lock, for even better resistance to attacks. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20251024090517.3289181-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-21net: add a common function to compute features for upper devicesHangbin Liu1-0/+88
Some high level software drivers need to compute features from lower devices. But each has their own implementations and may lost some feature compute. Let's use one common function to compute features for kinds of these devices. The new helper uses the current bond implementation as the reference one, as the latter already handles all the relevant aspects: netdev features, TSO limits and dst retention. Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://patch.msgid.link/20251017034155.61990-2-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-10-20net: add a fast path in __netif_schedule()Eric Dumazet1-0/+7
Cpus serving NIC interrupts and specifically TX completions are often trapped in also restarting a busy qdisc (because qdisc was stopped by BQL or the driver's own flow control). When they call netdev_tx_completed_queue() or netif_tx_wake_queue(), they call __netif_schedule() so that the queue can be run later from net_tx_action() (involving NET_TX_SOFTIRQ) Quite often, by the time the cpu reaches net_tx_action(), another cpu grabbed the qdisc spinlock from __dev_xmit_skb(), and we spend too much time spinning on this lock. We can detect in __netif_schedule() if a cpu is already at a specific point in __dev_xmit_skb() where we have the guarantee the queue will be run. This patch gives a 13 % increase of throughput on an IDPF NIC (200Gbit), 32 TX qeues, sending UDP packets of 120 bytes. This also helps __qdisc_run() to not force a NET_TX_SOFTIRQ if another thread is waiting in __dev_xmit_skb() Before: sar -n DEV 5 5|grep eth1|grep Average Average: eth1 1496.44 5219