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2024-09-11net: add support for skbs with unreadable fragsMina Almasry1-0/+4
For device memory TCP, we expect the skb headers to be available in host memory for access, and we expect the skb frags to be in device memory and unaccessible to the host. We expect there to be no mixing and matching of device memory frags (unaccessible) with host memory frags (accessible) in the same skb. Add a skb->devmem flag which indicates whether the frags in this skb are device memory frags or not. __skb_fill_netmem_desc() now checks frags added to skbs for net_iov, and marks the skb as skb->devmem accordingly. Add checks through the network stack to avoid accessing the frags of devmem skbs and avoid coalescing devmem skbs with non devmem skbs. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-9-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-11net: support non paged skb fragsMina Almasry1-1/+2
Make skb_frag_page() fail in the case where the frag is not backed by a page, and fix its relevant callers to handle this case. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-8-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-11netdev: support binding dma-buf to netdeviceMina Almasry1-0/+26
Add a netdev_dmabuf_binding struct which represents the dma-buf-to-netdevice binding. The netlink API will bind the dma-buf to rx queues on the netdevice. On the binding, the dma_buf_attach & dma_buf_map_attachment will occur. The entries in the sg_table from mapping will be inserted into a genpool to make it ready for allocation. The chunks in the genpool are owned by a dmabuf_chunk_owner struct which holds the dma-buf offset of the base of the chunk and the dma_addr of the chunk. Both are needed to use allocations that come from this chunk. We create a new type that represents an allocation from the genpool: net_iov. We setup the net_iov allocation size in the genpool to PAGE_SIZE for simplicity: to match the PAGE_SIZE normally allocated by the page pool and given to the drivers. The user can unbind the dmabuf from the netdevice by closing the netlink socket that established the binding. We do this so that the binding is automatically unbound even if the userspace process crashes. The binding and unbinding leaves an indicator in struct netdev_rx_queue that the given queue is bound, and the binding is actuated by resetting the rx queue using the queue API. The netdev_dmabuf_binding struct is refcounted, and releases its resources only when all the refs are released. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> # excluding netlink Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20240910171458.219195-4-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-09net: remove dev_pick_tx_cpu_id()Jakub Kicinski1-7/+0
dev_pick_tx_cpu_id() has been introduced with two users by commit a4ea8a3dacc3 ("net: Add generic ndo_select_queue functions"). The use in AF_PACKET has been removed in 2019 by commit b71b5837f871 ("packet: rework packet_pick_tx_queue() to use common code selection") The other user was a Netlogic XLP driver, removed in 2021 by commit 47ac6f567c28 ("staging: Remove Netlogic XLP network driver"). It's relatively unlikely that any modern driver will need an .ndo_select_queue implementation which picks purely based on CPU ID and skips XPS, delete dev_pick_tx_cpu_id() Found by code inspection. Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240906161059.715546-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-06net/core: make use of the helper macro LIST_HEAD()Hongbo Li1-4/+2
list_head can be initialized automatically with LIST_HEAD() instead of calling INIT_LIST_HEAD(). Here we can simplify the code. Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Link: https://patch.msgid.link/20240904093243.3345012-6-lihongbo22@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-03netdev_features: convert NETIF_F_NETNS_LOCAL to dev->netns_localAlexander Lobakin1-2/+2
"Interface can't change network namespaces" is rather an attribute, not a feature, and it can't be changed via Ethtool. Make it a "cold" private flag instead of a netdev_feature and free one more bit. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-09-03netdevice: convert private flags > BIT(31) to bitfieldsAlexander Lobakin1-2/+2
Make dev->priv_flags `u32` back and define bits higher than 31 as bitfield booleans as per Jakub's suggestion. This simplifies code which accesses these bits with no optimization loss (testb both before/after), allows to not extend &netdev_priv_flags each time, but also scales better as bits > 63 in the future would only add a new u64 to the structure with no complications, comparing to that extending ::priv_flags would require converting it to a bitmap. Note that I picked `unsigned long :1` to not lose any potential optimizations comparing to `bool :1` etc. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-29net: prefer strscpy over strcpyHongbo Li1-1/+1
The deprecated helper strcpy() performs no bounds checking on the destination buffer. This could result in linear overflows beyond the end of the buffer, leading to all kinds of misbehaviors. The safe replacement is strscpy() [1]. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy [1] Signed-off-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-26net: Correct spelling in net/coreSimon Horman1-3/+3
Correct spelling in net/core. As reported by codespell. Signed-off-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20240822-net-spell-v1-13-3a98971ce2d2@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-26Merge tag 'nf-next-24-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-nextJakub Kicinski1-0/+1
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following batch contains Netfilter updates for net-next: Patch #1 fix checksum calculation in nfnetlink_queue with SCTP, segment GSO packet since skb_zerocopy() does not support GSO_BY_FRAGS, from Antonio Ojea. Patch #2 extend nfnetlink_queue coverage to handle SCTP packets, from Antonio Ojea. Patch #3 uses consume_skb() instead of kfree_skb() in nfnetlink, from Donald Hunter. Patch #4 adds a dedicate commit list for sets to speed up intra-transaction lookups, from Florian Westphal. Patch #5 skips removal of element from abort path for the pipapo backend, ditching the shadow copy of this datastructure is sufficient. Patch #6 moves nf_ct_netns_get() out of nf_conncount_init() to let users of conncoiunt decide when to enable conntrack, this is needed by openvswitch, from Xin Long. Patch #7 pass context to all nft_parse_register_load() in preparation for the next patch. Patches #8 and #9 reject loads from uninitialized registers from control plane to remove register initialization from datapath. From Florian Westphal. * tag 'nf-next-24-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nf_tables: don't initialize registers in nft_do_chain() netfilter: nf_tables: allow loads only when register is initialized netfilter: nf_tables: pass context structure to nft_parse_register_load netfilter: move nf_ct_netns_get out of nf_conncount_init netfilter: nf_tables: do not remove elements if set backend implements .abort netfilter: nf_tables: store new sets in dedicated list netfilter: nfnetlink: convert kfree_skb to consume_skb selftests: netfilter: nft_queue.sh: sctp coverage netfilter: nfnetlink_queue: unbreak SCTP traffic ==================== Link: https://patch.msgid.link/20240822221939.157858-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-24net: refactor ->ndo_bpf calls into dev_xdp_propagateMina Almasry1-0/+9
When net devices propagate xdp configurations to slave devices, we will need to perform a memory provider check to ensure we're not binding xdp to a device using unreadable netmem. Currently the ->ndo_bpf calls in a few places. Adding checks to all these places would not be ideal. Refactor all the ->ndo_bpf calls into one place where we can add this check in the future. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-23net: phy: Introduce ethernet link topology representationMaxime Chevallier1-0/+15
Link topologies containing multiple network PHYs attached to the same net_device can be found when using a PHY as a media converter for use with an SFP connector, on which an SFP transceiver containing a PHY can be used. With the current model, the transceiver's PHY can't be used for operations such as cable testing, timestamping, macsec offload, etc. The reason being that most of the logic for these configuration, coming from either ethtool netlink or ioctls tend to use netdev->phydev, which in multi-phy systems will reference the PHY closest to the MAC. Introduce a numbering scheme allowing to enumerate PHY devices that belong to any netdev, which can in turn allow userspace to take more precise decisions with regard to each PHY's configuration. The numbering is maintained per-netdev, in a phy_device_list. The numbering works similarly to a netdevice's ifindex, with identifiers that are only recycled once INT_MAX has been reached. This prevents races that could occur between PHY listing and SFP transceiver removal/insertion. The identifiers are assigned at phy_attach time, as the numbering depends on the netdevice the phy is attached to. The PHY index can be re-used for PHYs that are persistent. Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-19netfilter: nfnetlink_queue: unbreak SCTP trafficAntonio Ojea1-0/+1
when packet is enqueued with nfqueue and GSO is enabled, checksum calculation has to take into account the protocol, as SCTP uses a 32 bits CRC checksum. Enter skb_gso_segment() path in case of SCTP GSO packets because skb_zerocopy() does not support for GSO_BY_FRAGS. Joint work with Pablo. Signed-off-by: Antonio Ojea <aojea@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-08-15netdev: Add missing __percpu qualifier to a castUros Bizjak1-1/+1
Add missing __percpu qualifier to a (void *) cast to fix dev.c:10863:45: warning: cast removes address space '__percpu' of expression sparse warning. Also remove now unneeded __force sparse directives. Found by GCC's named address space checks. There were no changes in the resulting object file. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Link: https://patch.msgid.link/20240814070748.943671-1-ubizjak@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-09net: Make USO depend on CSUM offloadJakub Sitnicki1-9/+17
UDP segmentation offload inherently depends on checksum offload. It should not be possible to disable checksum offload while leaving USO enabled. Enforce this dependency in code. There is a single tx-udp-segmentation feature flag to indicate support for both IPv4/6, hence the devices wishing to support USO must offer checksum offload for both IP versions. Fixes: 10154dbded6d ("udp: Allow GSO transmit from devices with no checksum offload") Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20240808-udp-gso-egress-from-tunnel-v4-1-f5c5b4149ab9@cloudflare.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-29tun: Add missing bpf_net_ctx_clear() in do_xdp_generic()Jeongjun Park1-0/+1
There are cases where do_xdp_generic returns bpf_net_context without clearing it. This causes various memory corruptions, so the missing bpf_net_ctx_clear must be added. Reported-by: syzbot+44623300f057a28baf1e@syzkaller.appspotmail.com Fixes: fecef4cd42c6 ("tun: Assign missing bpf_net_context.") Signed-off-by: Jeongjun Park <aha310510@gmail.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reported-by: syzbot+3c2b6d5d4bec3b904933@syzkaller.appspotmail.com Reported-by: syzbot+707d98c8649695eaf329@syzkaller.appspotmail.com Reported-by: syzbot+c226757eb784a9da3e8b@syzkaller.appspotmail.com Reported-by: syzbot+61a1cfc2b6632363d319@syzkaller.appspotmail.com Reported-by: syzbot+709e4c85c904bcd62735@syzkaller.appspotmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
2024-07-11netdevice: define and allocate &net_device _properly_Alexander Lobakin1-24/+6
In fact, this structure contains a flexible array at the end, but historically its size, alignment etc., is calculated manually. There are several instances of the structure embedded into other structures, but also there's ongoing effort to remove them and we could in the meantime declare &net_device properly. Declare the array explicitly, use struct_size() and store the array size inside the structure, so that __counted_by() can be applied. Don't use PTR_ALIGN(), as SLUB itself tries its best to ensure the allocated buffer is aligned to what the user expects. Also, change its alignment from %NETDEV_ALIGN to the cacheline size as per several suggestions on the netdev ML. bloat-o-meter for vmlinux: free_netdev 445 440 -5 netdev_freemem 24 - -24 alloc_netdev_mqs 1481 1450 -31 On x86_64 with several NICs of different vendors, I was never able to get a &net_device pointer not aligned to the cacheline size after the change. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20240710113036.2125584-1-leitao@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-05tun: Assign missing bpf_net_context.Sebastian Andrzej Siewior1-0/+5
During the introduction of struct bpf_net_context handling for XDP-redirect, the tun driver has been missed. Jakub also pointed out that there is another call chain to do_xdp_generic() originating from netif_receive_skb() and drivers may use it outside from the NAPI context. Set the bpf_net_context before invoking BPF XDP program within the TUN driver. Set the bpf_net_context also in do_xdp_generic() if a xdp program is available. Reported-by: syzbot+0b5c75599f1d872bea6f@syzkaller.appspotmail.com Reported-by: syzbot+5ae46b237278e2369cac@syzkaller.appspotmail.com Reported-by: syzbot+c1e04a422bbc0f0f2921@syzkaller.appspotmail.com Fixes: 401cb7dae8130 ("net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240704144815.j8xQda5r@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28net: ethtool: add a mutex protecting RSS contextsEdward Cree1-0/+5
While this is not needed to serialise the ethtool entry points (which are all under RTNL), drivers may have cause to asynchronously access dev->ethtool->rss_ctx; taking dev->ethtool->rss_lock allows them to do this safely without needing to take the RTNL. Signed-off-by: Edward Cree <ecree.xilinx@gmail.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Link: https://patch.msgid.link/7f9c15eb7525bf87af62c275dde3a8570ee8bf0a.1719502240.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28net: ethtool: add an extack parameter to new rxfh_context APIsEdward Cree1-1/+1
Currently passed as NULL, but will allow drivers to report back errors when ethnl support for these ops is added. Signed-off-by: Edward Cree <ecree.xilinx@gmail.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Link: https://patch.msgid.link/6e0012347d175fdd1280363d7bfa76a2f2777e17.1719502240.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28net: ethtool: let the core choose RSS context IDsEdward Cree1-1/+5
Add a new API to create/modify/remove RSS contexts, that passes in the newly-chosen context ID (not as a pointer) rather than leaving the driver to choose it on create. Also pass in the ctx, allowing drivers to easily use its private data area to store their hardware-specific state. Keep the existing .set_rxfh API for now as a fallback, but deprecate it for custom contexts (rss_context != 0). Signed-off-by: Edward Cree <ecree.xilinx@gmail.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Link: https://patch.msgid.link/45f1fe61df2163c091ec394c9f52000c8b16cc3b.1719502240.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28net: ethtool: attach an XArray of custom RSS contexts to a netdeviceEdward Cree1-0/+27
Each context stores the RXFH settings (indir, key, and hfunc) as well as optionally some driver private data. Delete any still-existing contexts at netdev unregister time. Signed-off-by: Edward Cree <ecree.xilinx@gmail.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Link: https://patch.msgid.link/cbd1c402cec38f2e03124f2ab65b4ae4e08bd90d.1719502240.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-28net: move ethtool-related netdev state into its own structEdward Cree1-0/+4
net_dev->ethtool is a pointer to new struct ethtool_netdev_state, which currently contains only the wol_enabled field. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Edward Cree <ecree.xilinx@gmail.com> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Link: https://patch.msgid.link/293a562278371de7534ed1eb17531838ca090633.1719502239.git.ecree.xilinx@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-6/+6
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: e3f02f32a050 ("ionic: fix kernel panic due to multi-buffer handling") d9c04209990b ("ionic: Mark error paths in the data path as unlikely") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24net: Reference bpf_redirect_info via task_struct on PREEMPT_RT.Sebastian Andrzej Siewior1-1/+28
The XDP redirect process is two staged: - bpf_prog_run_xdp() is invoked to run a eBPF program which inspects the packet and makes decisions. While doing that, the per-CPU variable bpf_redirect_info is used. - Afterwards xdp_do_redirect() is invoked and accesses bpf_redirect_info and it may also access other per-CPU variables like xskmap_flush_list. At the very end of the NAPI callback, xdp_do_flush() is invoked which does not access bpf_redirect_info but will touch the individual per-CPU lists. The per-CPU variables are only used in the NAPI callback hence disabling bottom halves is the only protection mechanism. Users from preemptible context (like cpu_map_kthread_run()) explicitly disable bottom halves for protections reasons. Without locking in local_bh_disable() on PREEMPT_RT this data structure requires explicit locking. PREEMPT_RT has forced-threaded interrupts enabled and every NAPI-callback runs in a thread. If each thread has its own data structure then locking can be avoided. Create a struct bpf_net_context which contains struct bpf_redirect_info. Define the variable on stack, use bpf_net_ctx_set() to save a pointer to it, bpf_net_ctx_clear() removes it again. The bpf_net_ctx_set() may nest. For instance a function can be used from within NET_RX_SOFTIRQ/ net_rx_action which uses bpf_net_ctx_set() and NET_TX_SOFTIRQ which does not. Therefore only the first invocations updates the pointer. Use bpf_net_ctx_get_ri() as a wrapper to retrieve the current struct bpf_redirect_info. The returned data structure is zero initialized to ensure nothing is leaked from stack. This is done on first usage of the struct. bpf_net_ctx_set() sets bpf_redirect_info::kern_flags to 0 to note that initialisation is required. First invocation of bpf_net_ctx_get_ri() will memset() the data structure and update bpf_redirect_info::kern_flags. bpf_redirect_info::nh is excluded from memset because it is only used once BPF_F_NEIGH is set which also sets the nh member. The kern_flags is moved past nh to exclude it from memset. The pointer to bpf_net_context is saved task's task_struct. Using always the bpf_net_context approach has the advantage that there is almost zero differences between PREEMPT_RT and non-PREEMPT_RT builds. Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Yonghong Song <yonghong.song@linux.dev> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240620132727.660738-15-bigeasy@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24dev: Use nested-BH locking for softnet_data.process_queue.Sebastian Andrzej Siewior1-1/+11
softnet_data::process_queue is a per-CPU variable and relies on disabled BH for its locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this data structure requires explicit locking. softnet_data::input_queue_head can be updated lockless. This is fine because this value is only update CPU local by the local backlog_napi thread. Add a local_lock_t to softnet_data and use local_lock_nested_bh() for locking of process_queue. This change adds only lockdep coverage and does not alter the functional behaviour for !PREEMPT_RT. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240620132727.660738-11-bigeasy@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24dev: Remove PREEMPT_RT ifdefs from backlog_lock.*().Sebastian Andrzej Siewior1-4/+4
The backlog_napi locking (previously RPS) relies on explicit locking if either RPS or backlog NAPI is enabled. If both are disabled then locking was achieved by disabling interrupts except on PREEMPT_RT. PREEMPT_RT was excluded because the needed synchronisation was already provided local_bh_disable(). Since the introduction of backlog NAPI and making it mandatory for PREEMPT_RT the ifdef within backlog_lock.*() is obsolete and can be removed. Remove the ifdefs in backlog_lock.*(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240620132727.660738-10-bigeasy@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24net: softnet_data: Make xmit per task.Sebastian Andrzej Siewior1-0/+14
Softirq is preemptible on PREEMPT_RT. Without a per-CPU lock in local_bh_disable() there is no guarantee that only one device is transmitting at a time. With preemption and multiple senders it is possible that the per-CPU `recursion' counter gets incremented by different threads and exceeds XMIT_RECURSION_LIMIT leading to a false positive recursion alert. The `more' member is subject to similar problems if set by one thread for one driver and wrongly used by another driver within another thread. Instead of adding a lock to protect the per-CPU variable it is simpler to make xmit per-task. Sending and receiving skbs happens always in thread context anyway. Having a lock to protected the per-CPU counter would block/ serialize two sending threads needlessly. It would also require a recursive lock to ensure that the owner can increment the counter further. Make the softnet_data.xmit a task_struct member on PREEMPT_RT. Add needed wrapper. Cc: Ben Segall <bsegall@google.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20240620132727.660738-9-bigeasy@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-21net: add softirq safety to netdev_rename_lockEric Dumazet1-6/+6
syzbot reported a lockdep violation involving bridge driver [1] Make sure netdev_rename_lock is softirq safe to fix this issue. [1] WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0 Not tainted ----------------------------------------------------- syz-executor.2/9449 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire: ffffffff8f5de668 (netdev_rename_lock.seqcount){+.+.}-{0:0}, at: rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839 and this task is already holding: ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: br_port_slave_changelink+0x3d/0x150 net/bridge/br_netlink.c:1212 which would create a new lock dependency: (&br->lock){+.-.}-{2:2} -> (netdev_rename_lock.seqcount){+.+.}-{0:0} but this new dependency connects a SOFTIRQ-irq-safe lock: (&br->lock){+.-.}-{2:2} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers kernel/time/timer.c:2417 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428 run_timer_base kernel/time/timer.c:2437 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 fs_reclaim_acquire+0xaf/0x140 mm/page_alloc.c:3800 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3890 [inline] slab_alloc_node mm/slub.c:3980 [inline] kmalloc_trace_noprof+0x3d/0x2c0 mm/slub.c:4147 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] class_dir_create_and_add drivers/base/core.c:3255 [inline] get_device_parent+0x2a7/0x410 drivers/base/core.c:3315 device_add+0x325/0xbf0 drivers/base/core.c:3645 netdev_register_kobject+0x17e/0x320 net/core/net-sysfs.c:2136 register_netdevice+0x11d5/0x19e0 net/core/dev.c:10375 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:690 [inline] nsim_create+0x647/0x890 drivers/net/netdevsim/netdev.c:750 __nsim_dev_port_add+0x6c0/0xae0 drivers/net/netdevsim/dev.c:1390 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1446 [inline] nsim_dev_reload_create drivers/net/netdevsim/dev.c:1498 [inline] nsim_dev_reload_up+0x69b/0x8e0 drivers/net/netdevsim/dev.c:985 devlink_reload+0x478/0x870 net/devlink/dev.c:474 devlink_nl_reload_doit+0xbd6/0xe50 net/devlink/dev.c:586 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 ___sys_sendmsg net/socket.c:2639 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f to a SOFTIRQ-irq-unsafe lock: (netdev_rename_lock.seqcount){+.+.}-{0:0} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline] do_write_seqcount_begin include/linux/seqlock.h:495 [inline] write_seqlock include/linux/seqlock.h:823 [inline] dev_change_name+0x184/0x920 net/core/dev.c:1229 do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880 __rtnl_newlink net/core/rtnetlink.c:3696 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(netdev_rename_lock.seqcount); local_irq_disable(); lock(&br->lock); lock(netdev_rename_lock.seqcount); <Interrupt> lock(&br->lock); *** DEADLOCK *** 3 locks held by syz-executor.2/9449: #0: ffffffff8f5e7448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f5e7448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x1180 net/core/rtnetlink.c:6632 #1: ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #1: ffff888060c64cb8 (&br->lock){+.-.}-{2:2}, at: br_port_slave_changelink+0x3d/0x150 net/bridge/br_netlink.c:1212 #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: team_change_rx_flags+0x29/0x330 drivers/net/team/team_core.c:1767 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&br->lock){+.-.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] br_add_if+0xb34/0xef0 net/bridge/br_if.c:682 do_set_master net/core/rtnetlink.c:2701 [inline] do_setlink+0xe70/0x41f0 net/core/rtnetlink.c:2907 __rtnl_newlink net/core/rtnetlink.c:3696 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f IN-SOFTIRQ-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers kernel/time/timer.c:2417 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428 run_timer_base kernel/time/timer.c:2437 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 fs_reclaim_acquire+0xaf/0x140 mm/page_alloc.c:3800 might_alloc include/linux/sched/mm.h:334 [inline] slab_pre_alloc_hook mm/slub.c:3890 [inline] slab_alloc_node mm/slub.c:3980 [inline] kmalloc_trace_noprof+0x3d/0x2c0 mm/slub.c:4147 kmalloc_noprof include/linux/slab.h:660 [inline] kzalloc_noprof include/linux/slab.h:778 [inline] class_dir_create_and_add drivers/base/core.c:3255 [inline] get_device_parent+0x2a7/0x410 drivers/base/core.c:3315 device_add+0x325/0xbf0 drivers/base/core.c:3645 netdev_register_kobject+0x17e/0x320 net/core/net-sysfs.c:2136 register_netdevice+0x11d5/0x19e0 net/core/dev.c:10375 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:690 [inline] nsim_create+0x647/0x890 drivers/net/netdevsim/netdev.c:750 __nsim_dev_port_add+0x6c0/0xae0 drivers/net/netdevsim/dev.c:1390 nsim_dev_port_add_all drivers/net/netdevsim/dev.c:1446 [inline] nsim_dev_reload_create drivers/net/netdevsim/dev.c:1498 [inline] nsim_dev_reload_up+0x69b/0x8e0 drivers/net/netdevsim/dev.c:985 devlink_reload+0x478/0x870 net/devlink/dev.c:474 devlink_nl_reload_doit+0xbd6/0xe50 net/devlink/dev.c:586 genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 ___sys_sendmsg net/socket.c:2639 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] br_add_if+0xb34/0xef0 net/bridge/br_if.c:682 do_set_master net/core/rtnetlink.c:2701 [inline] do_setlink+0xe70/0x41f0 net/core/rtnetlink.c:2907 __rtnl_newlink net/core/rtnetlink.c:3696 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f } ... key at: [<ffffffff94b9a1a0>] br_dev_setup.__key+0x0/0x20 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (netdev_rename_lock.seqcount){+.+.}-{0:0} { HARDIRQ-ON-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline] do_write_seqcount_begin include/linux/seqlock.h:495 [inline] write_seqlock include/linux/seqlock.h:823 [inline] dev_change_name+0x184/0x920 net/core/dev.c:1229 do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880 __rtnl_newlink net/core/rtnetlink.c:3696 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f SOFTIRQ-ON-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline] do_write_seqcount_begin include/linux/seqlock.h:495 [inline] write_seqlock include/linux/seqlock.h:823 [inline] dev_change_name+0x184/0x920 net/core/dev.c:1229 do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880 __rtnl_newlink net/core/rtnetlink.c:3696 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 do_write_seqcount_begin_nested include/linux/seqlock.h:469 [inline] do_write_seqcount_begin include/linux/seqlock.h:495 [inline] write_seqlock include/linux/seqlock.h:823 [inline] dev_change_name+0x184/0x920 net/core/dev.c:1229 do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2880 __rtnl_newlink net/core/rtnetlink.c:3696 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] read_seqbegin include/linux/seqlock.h:772 [inline] netdev_copy_name+0x168/0x2c0 net/core/dev.c:949 rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839 rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4073 rtmsg_ifinfo_event net/core/rtnetlink.c:4107 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4116 register_netdevice+0x1665/0x19e0 net/core/dev.c:10422 register_netdev+0x3b/0x50 net/core/dev.c:10512 loopback_net_init+0x73/0x150 drivers/net/loopback.c:217 ops_init+0x359/0x610 net/core/net_namespace.c:139 __register_pernet_operations net/core/net_namespace.c:1247 [inline] register_pernet_operations+0x2cb/0x660 net/core/net_namespace.c:1320 register_pernet_device+0x33/0x80 net/core/net_namespace.c:1407 net_dev_init+0xfcd/0x10d0 net/core/dev.c:11956 do_one_initcall+0x248/0x880 init/main.c:1267 do_initcall_level+0x157/0x210 init/main.c:1329 do_initcalls+0x3f/0x80 init/main.c:1345 kernel_init_freeable+0x435/0x5d0 init/main.c:1578 kernel_init+0x1d/0x2b0 init/main.c:1467 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 } ... key at: [<ffffffff8f5de668>] netdev_rename_lock+0x8/0xa0 ... acquired at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] read_seqbegin include/linux/seqlock.h:772 [inline] netdev_copy_name+0x168/0x2c0 net/core/dev.c:949 rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839 rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4073 rtmsg_ifinfo_event net/core/rtnetlink.c:4107 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4116 __dev_notify_flags+0xf7/0x400 net/core/dev.c:8816 __dev_set_promiscuity+0x152/0x5a0 net/core/dev.c:8588 dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608 team_change_rx_flags+0x203/0x330 drivers/net/team/team_core.c:1771 dev_change_rx_flags net/core/dev.c:8541 [inline] __dev_set_promiscuity+0x406/0x5a0 net/core/dev.c:8585 dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608 br_port_clear_promisc net/bridge/br_if.c:135 [inline] br_manage_promisc+0x505/0x590 net/bridge/br_if.c:172 nbp_update_port_count net/bridge/br_if.c:242 [inline] br_port_flags_change+0x161/0x1f0 net/bridge/br_if.c:761 br_setport+0xcb5/0x16d0 net/bridge/br_netlink.c:1000 br_port_slave_changelink+0x135/0x150 net/bridge/br_netlink.c:1213 __rtnl_newlink net/core/rtnetlink.c:3689 [inline] rtnl_newlink+0x169f/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 ___sys_sendmsg net/socket.c:2639 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f stack backtrace: CPU: 0 PID: 9449 Comm: syz-executor.2 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline] check_irq_usage kernel/locking/lockdep.c:2865 [inline] check_prev_add kernel/locking/lockdep.c:3138 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x4de0/0x5900 kernel/locking/lockdep.c:3869 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 seqcount_lockdep_reader_access include/linux/seqlock.h:72 [inline] read_seqbegin include/linux/seqlock.h:772 [inline] netdev_copy_name+0x168/0x2c0 net/core/dev.c:949 rtnl_fill_ifinfo+0x38e/0x2270 net/core/rtnetlink.c:1839 rtmsg_ifinfo_build_skb+0x18a/0x260 net/core/rtnetlink.c:4073 rtmsg_ifinfo_event net/core/rtnetlink.c:4107 [inline] rtmsg_ifinfo+0x91/0x1b0 net/core/rtnetlink.c:4116 __dev_notify_flags+0xf7/0x400 net/core/dev.c:8816 __dev_set_promiscuity+0x152/0x5a0 net/core/dev.c:8588 dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608 team_change_rx_flags+0x203/0x330 drivers/net/team/team_core.c:1771 dev_change_rx_flags net/core/dev.c:8541 [inline] __dev_set_promiscuity+0x406/0x5a0 net/core/dev.c:8585 dev_set_promiscuity+0x51/0xe0 net/core/dev.c:8608 br_port_clear_promisc net/bridge/br_if.c:135 [inline] br_manage_promisc+0x505/0x590 net/bridge/br_if.c:172 nbp_update_port_count net/bridge/br_if.c:242 [inline] br_port_flags_change+0x161/0x1f0 net/bridge/br_if.c:761 br_setport+0xcb5/0x16d0 net/bridge/br_netlink.c:1000 br_port_slave_changelink+0x135/0x150 net/bridge/br_netlink.c:1213 __rtnl_newlink net/core/rtnetlink.c:3689 [inline] rtnl_newlink+0x169f/0x20a0 net/core/rtnetlink.c:3743 rtnetlink_rcv_msg+0x89b/0x1180 net/core/rtnetlink.c:6635 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585 ___sys_sendmsg net/socket.c:2639 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3b3047cf29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3b311740c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3b305b4050 RCX: 00007f3b3047cf29 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000008 RBP: 00007f3b304ec074 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f3b305b4050 R15: 00007ffca2f3dc68 </TASK> Fixes: 0840556e5a3a ("net: Protect dev->name by seqlock.") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-06-19net: add rx_sk to trace_kfree_skbYan Zhai1-1/+1
skb does not include enough information to find out receiving sockets/services and netns/containers on packet drops. In theory skb->dev tells about netns, but it can get cleared/reused, e.g. by TCP stack for OOO packet lookup. Similarly, skb->sk often identifies a local sender, and tells nothing about a receiver. Allow passing an extra receiving socket to the tracepoint to improve the visibility on receiving drops. Signed-off-by: Yan Zhai <yan@cloudflare.com> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-06-11net: core: Implement dstats-type stats collectionsJeremy Kerr1-0/+50
We currently have dev_get_tstats64() for collecting per-cpu stats of type pcpu_sw_netstats ("tstats"). However, tstats doesn't allow for accounting tx/rx drops. We do have a stats variant that does have stats for dropped packets: struct pcpu_dstats, but there are no core helpers for using those stats. The VRF driver uses dstats, by providing its own collation/fetch functions to do so. This change adds a common implementation for dstats-type collection, used when pcpu_stat_type == NETDEV_PCPU_STAT_DSTAT. This is based on the VRF driver's existing stats collator (plus the unused tx_drops stat from there). We will switch the VRF driver to use this in the next change. Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240607-dstats-v3-2-cc781fe116f7@codeconstruct.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+2
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: drivers/net/ethernet/pensando/ionic/ionic_txrx.c d9c04209990b ("ionic: Mark error paths in the data path as unlikely") 491aee894a08 ("ionic: fix kernel panic in XDP_TX action") net/ipv6/ip6_fib.c b4cb4a1391dc ("net: use unrcu_pointer() helper") b01e1c030770 ("ipv6: fix possible race in __fib6_drop_pcpu_from()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-01net: rps: fix error when CONFIG_RFS_ACCEL is offJason Xing1-1/+2
John Sperbeck reported that if we turn off CONFIG_RFS_ACCEL, the 'head' is not defined, which will trigger compile error. So I move the 'head' out of the CONFIG_RFS_ACCEL scope. Fixes: 84b6823cd96b ("net: rps: protect last_qtail with rps_input_queue_tail_save() helper") Reported-by: John Sperbeck <jsperbeck@google.com> Closes: https://lore.kernel.org/all/20240529203421.2432481-1-jsperbeck@google.com/ Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240530032717.57787-1-kerneljasonxing@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-23net: Rename mono_delivery_time to tstamp_type for scalabiltyAbhishek Chauhan1-1/+1
mono_delivery_time was added to check if skb->tstamp has delivery time in mono clock base (i.e. EDT) otherwise skb->tstamp has timestamp in ingress and delivery_time at egress. Renaming the bitfield from mono_delivery_time to tstamp_type is for extensibilty for other timestamps such as userspace timestamp (i.e. SO_TXTIME) set via sock opts. As we are renaming the mono_delivery_time to tstamp_type, it makes sense to start assigning tstamp_type based on enum defined in this commit. Earlier we used bool arg flag to check if the tstamp is mono in function skb_set_delivery_time, Now the signature of the functions accepts tstamp_type to distinguish between mono and real time. Also skb_set_delivery_type_by_clockid is a new function which accepts clockid to determine the tstamp_type. In future tstamp_type:1 can be extended to support userspace timestamp by increasing the bitfield. Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-05-13net: revert partially applied PHY topology seriesJakub Kicinski1-9/+0
The series is causing issues with PHY drivers built as modules. Since it was only partially applied and the merge window has opened let's revert and try again for v6.11. Revert 6916e461e793 ("net: phy: Introduce ethernet link topology representation") Revert 0ec5ed6c130e ("net: sfp: pass the phy_device when disconnecting an sfp module's PHY") Revert e75e4e074c44 ("net: phy: add helpers to handle sfp phy connect/disconnect") Revert fdd353965b52 ("net: sfp: Add helper to return the SFP bus name") Revert 841942bc6212 ("net: ethtool: Allow passing a phy index for some commands") Link: https://lore.kernel.org/all/171242462917.4000.9759453824684907063.git-patchwork-notify@kernel.org/ Link: https://lore.kernel.org/all/20240507102822.2023826-1-maxime.chevallier@bootlin.com/ Link: https://lore.kernel.org/r/20240513154156.104281-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-07rtnetlink: do not depend on RTNL in rtnl_fill_proto_down()Eric Dumazet1-4/+7
Change dev_change_proto_down() and dev_change_proto_down_reason() to write once on dev->proto_down and dev->proto_down_reason. Then rtnl_fill_proto_down() can use READ_ONCE() annotations and run locklessly. rtnl_proto_down_size() should assume worst case, because readng dev->proto_down_reason multiple times would be racy without RTNL in the future. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07net: write once on dev->allmulti and dev->promiscuityEric Dumazet1-16/+20
In the following patch we want to read dev->allmulti and dev->promiscuity locklessly from rtnl_fill_ifinfo() In this patch I change __dev_set_promiscuity() and __dev_set_allmulti() to write these fields (and dev->flags) only if they succeed, with WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07rtnetlink: do not depend on RTNL for IFLA_TXQLEN outputEric Dumazet1-2/+2
rtnl_fill_ifinfo() can read dev->tx_queue_len locklessly, granted we add corresponding READ_ONCE()/WRITE_ONCE() annotations. Add missing READ_ONCE(dev->tx_queue_len) in teql_enqueue() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-03net: no longer acquire RTNL in threaded_show()Eric Dumazet1-2/+2
dev->threaded can be read locklessly, if we add corresponding READ_ONCE()/WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240502173926.2010646-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-01net: Protect dev->name by seqlock.Kuniyuki Iwashima1-4/+23
We will convert ioctl(SIOCGARP) to RCU, and then we need to copy dev->name which is currently protected by rtnl_lock(). This patch does the following: 1) Add seqlock netdev_rename_lock to protect dev->name 2) Add netdev_copy_name() that copies dev->name to buffer under netdev_rename_lock 3) Use netdev_copy_name() in netdev_get_name() and drop devnet_rename_sem Suggested-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/CANn89iJEWs7AYSJqGCUABeVqOCTkErponfZdT5kV-iD=-SajnQ@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240430015813.71143-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-30net: move sysctl_skb_defer_max to net_hotdataEric Dumazet1-1/+0
sysctl_skb_defer_max is used in TCP fast path, move it to net_hodata. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240429134025.1233626-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-29net: give more chances to rcu in netdev_wait_allrefs_any()Eric Dumazet1-1/+2
This came while reviewing commit c4e86b4363ac ("net: add two more call_rcu_hurry()"). Paolo asked if adding one synchronize_rcu() would help. While synchronize_rcu() does not help, making sure to call rcu_barrier() before msleep(wait) is definitely helping to make sure lazy call_rcu() are completed. Instead of waiting ~100 seconds in my tests, the ref_tracker splats occurs one time only, and netdev_wait_allrefs_any() latency is reduced to the strict minimum. Ideally we should audit our call_rcu() users to make sure no refcount (or cascading call_rcu()) is held too long, because rcu_barrier() is quite expensive. Fixes: 0e4be9e57e8c ("net: use exponential backoff in netdev_wait_allrefs") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/all/28bbf698-befb-42f6-b561-851c67f464aa@kernel.org/T/#m76d73ed6b03cd930778ac4d20a777f22a08d6824 Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-24net: create a dummy net_device allocatorBreno Leitao1-18/+38
It is impossible to use init_dummy_netdev together with alloc_netdev() as the 'setup' argument. This is because alloc_netdev() initializes some fields in the net_device structure, and later init_dummy_netdev() memzero them all. This causes some problems as reported here: https://lore.kernel.org/all/20240322082336.49f110cc@kernel.org/ Split the init_dummy_netdev() function in two. Create a new function called init_dummy_netdev_core() that does not memzero the net_device structure. Then have init_dummy_netdev() memzero-ing and calling init_dummy_netdev_core(), keeping the old behaviour. init_dummy_netdev_core() is the new function that could be called as an argument for alloc_netdev(). Also, create a helper to allocate and initialize dummy net devices, leveraging init_dummy_netdev_core() as the setup argument. This function basically simplify the allocation of dummy devices, by allocating and initializing it. Freeing the device continue to be done through free_netdev() Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-24net: free_netdev: exit earlier if dummyBreno Leitao1-1/+2
For dummy devices, exit earlier at free_netdev() instead of executing the whole function. This is necessary, because dummy devices are special, and shouldn't have the second part of the function executed. Otherwise reg_state, which is NETREG_DUMMY, will be overwritten and there will be no way to identify that this is a dummy device. Also, this device do not need the final put_device(), since dummy devices are not registered (through register_netdevice()), where the device reference is increased (at netdev_register_kobject()/device_add()). Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-24net: core: Fix documentationBreno Leitao1-2/+2
Fix bad grammar in description of init_dummy_netdev() function. This topic showed up in the review of the "allocate dummy device dynamically" patch set. Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-19net: rps: locklessly access rflow->cpuJason Xing1-1/+1
This is the last member in struct rps_dev_flow which should be protected locklessly. So finish it. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-19net: rps: protect filter locklesslyJason Xing1-4/+4
As we can see, rflow->filter can be written/read concurrently, so lockless access is needed. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-19net: rps: protect last_qtail with rps_input_queue_tail_save() helperJason Xing1-4/+4
Removing one unnecessary reader protection and add another writer protection to finish the locklessly proctection job. Note: the removed READ_ONCE() is not needed because we only have to protect the locklessly reader in the different context (rps_may_expire_flow()). Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+6
Cross-merge networking fixes after downstream PR. Conflicts: include/trace/events/rpcgss.h 386f4a737964 ("trace: events: cleanup deprecated strncpy uses") a4833e3abae1 ("SUNRPC: Fix rpcgss_context trace event acceptor field") Adjacent changes: drivers/net/ethernet/intel/ice/ice_tc_lib.c 2cca35f5dd78 ("ice: Fix checking for unsupported keys on non-tunnel device") 784feaa65dfd ("ice: Add support for PFCP hardware offload in switchdev") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-17net/sched: Fix mirred deadlock on device recursionEric Dumazet1-0/+6
When the mirred action is used on a classful egress qdisc and a packet is mirrored or redirected to self we hit a qdisc lock deadlock. See trace below. [..... other info removed for brevity....] [ 82.890906] [ 82.890906] ============================================ [ 82.890906] WARNING: possible recursive locking detected [ 82.890906] 6.8.0-05205-g77fadd89fe2d-dirty #213 Tainted: G W [ 82.890906] -------------------------------------------- [ 82.890906] ping/418 is trying to acquire lock: [ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at: __dev_queue_xmit+0x1778/0x3550 [ 82.890906] [ 82.890906] but task is already holding lock: [ 82.890906] ffff888006994110 (&sch->q.lock){+.-.}-{3:3}, at: __dev_queue_xmit+0x1778/0x3550 [ 82.890906] [ 82.890906] other info that might help us debug this: [ 82.890906] Possible unsafe locking scenario: [ 82.890906] [ 82.890906] CPU0 [ 82.890906] ---- [ 82.890906] lock(&sch->q.lock); [ 82.890906] lock(&sch->q.lock); [ 82.890906] [ 82.890906] *** DEADLOCK *** [ 82.890906] [..... other info removed for brevity....] Example setup (eth0->eth0) to recreate tc qdisc add dev eth0 root handle 1: htb default 30 tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \ action mirred egress redirect dev eth0 Another example(eth0->eth1->eth0) to recreate tc qdisc add dev eth0 root handle 1: htb default 30 tc filter add dev eth0 handle 1: protocol ip prio 2 matchall \ action mirred egress redirect dev eth1 tc qdisc add dev eth1 root handle 1: htb default 30 tc filter add dev eth1 handle 1: protocol ip prio 2 matchall \ action mirred egress redirect dev eth0 We fix this by adding an owner field (CPU id) to struct Qdisc set after root qdisc is entered. When the softirq enters it a second time, if the qdisc owner is the same CPU, the packet is dropped to break the loop. Reported-by: Mingshuai Ren <renmingshuai@huawei.com> Closes: https://lore.kernel.org/netdev/20240314111713.5979-1-renmingshuai@huawei.com/ Fixes: 3bcb846ca4cf ("net: get rid of spin_trylock() in net_tx_action()") Fixes: e578d9c02587 ("net: sched: use counter to break reclassify loops") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Reviewed-by: Pedro Tammela <pctammela@mojatatu.com> Tested-by: Jamal Hadi Salim <jhs@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20240415210728.36949-1-victor@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>