Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 267 insertions, 0 deletions

diff --git a/Documentation/bpf/graph_ds_impl.rst b/Documentation/bpf/graph_ds_impl.rst
new file mode 100644
index 000000000..61274622b
--- /dev/null
+++ b/Documentation/bpf/graph_ds_impl.rst
@@ -0,0 +1,267 @@
+=========================
+BPF Graph Data Structures
+=========================
+
+This document describes implementation details of new-style "graph" data
+structures (linked_list, rbtree), with particular focus on the verifier's
+implementation of semantics specific to those data structures.
+
+Although no specific verifier code is referred to in this document, the document
+assumes that the reader has general knowledge of BPF verifier internals, BPF
+maps, and BPF program writing.
+
+Note that the intent of this document is to describe the current state of
+these graph data structures. **No guarantees** of stability for either
+semantics or APIs are made or implied here.
+
+.. contents::
+    :local:
+    :depth: 2
+
+Introduction
+------------
+
+The BPF map API has historically been the main way to expose data structures
+of various types for use within BPF programs. Some data structures fit naturally
+with the map API (HASH, ARRAY), others less so. Consequentially, programs
+interacting with the latter group of data structures can be hard to parse
+for kernel programmers without previous BPF experience.
+
+Luckily, some restrictions which necessitated the use of BPF map semantics are
+no longer relevant. With the introduction of kfuncs, kptrs, and the any-context
+BPF allocator, it is now possible to implement BPF data structures whose API
+and semantics more closely match those exposed to the rest of the kernel.
+
+Two such data structures - linked_list and rbtree - have many verification
+details in common. Because both have "root"s ("head" for linked_list) and
+"node"s, the verifier code and this document refer to common functionality
+as "graph_api", "graph_root", "graph_node", etc.
+
+Unless otherwise stated, examples and semantics below apply to both graph data
+structures.
+
+Unstable API
+------------
+
+Data structures implemented using the BPF map API have historically used BPF
+helper functions - either standard map API helpers like ``bpf_map_update_elem``
+or map-specific helpers. The new-style graph data structures instead use kfuncs
+to define their manipulation helpers. Because there are no stability guarantees
+for kfuncs, the API and semantics for these data structures can be evolved in
+a way that breaks backwards compatibility if necessary.
+
+Root and node types for the new data structures are opaquely defined in the
+``uapi/linux/bpf.h`` header.
+
+Locking
+-------
+
+The new-style data structures are intrusive and are defined similarly to their
+vanilla kernel counterparts:
+
+.. code-block:: c
+
+        struct node_data {
+          long key;
+          long data;
+          struct bpf_rb_node node;
+        };
+
+        struct bpf_spin_lock glock;
+        struct bpf_rb_root groot __contains(node_data, node);
+
+The "root" type for both linked_list and rbtree expects to be in a map_value
+which also contains a ``bpf_spin_lock`` - in the above example both global
+variables are placed in a single-value arraymap. The verifier considers this
+spin_lock to be associated with the ``bpf_rb_root`` by virtue of both being in
+the same map_value and will enforce that the correct lock is held when
+verifying BPF programs that manipulate the tree. Since this lock checking
+happens at verification time, there is no runtime penalty.
+
+Non-owning references
+---------------------
+
+**Motivation**
+
+Consider the following BPF code:
+
+.. code-block:: c
+
+        struct node_data *n = bpf_obj_new(typeof(*n)); /* ACQUIRED */
+
+        bpf_spin_lock(&lock);
+
+        bpf_rbtree_add(&tree, n); /* PASSED */
+
+        bpf_spin_unlock(&lock);
+
+From the verifier's perspective, the pointer ``n`` returned from ``bpf_obj_new``
+has type ``PTR_TO_BTF_ID | MEM_ALLOC``, with a ``btf_id`` of
+``struct node_data`` and a nonzero ``ref_obj_id``. Because it holds ``n``, the
+program has ownership of the pointee's (object pointed to by ``n``) lifetime.
+The BPF program must pass off ownership before exiting - either via
+``bpf_obj_drop``, which ``free``'s the object, or by adding it to ``tree`` with
+``bpf_rbtree_add``.
+
+(``ACQUIRED`` and ``PASSED`` comments in the example denote statements where
+"ownership is acquired" and "ownership is passed", respectively)
+
+What should the verifier do with ``n`` after ownership is passed off? If the
+object was ``free``'d with ``bpf_obj_drop`` the answer is obvious: the verifier
+should reject programs which attempt to access ``n`` after ``bpf_obj_drop`` as
+the object is no longer valid. The underlying memory may have been reused for
+some other allocation, unmapped, etc.
+
+When ownership is passed to ``tree`` via ``bpf_rbtree_add`` the answer is less
+obvious. The verifier could enforce the same semantics as for ``bpf_obj_drop``,
+but that would result in programs with useful, common coding patterns being
+rejected, e.g.:
+
+.. code-block:: c
+
+        int x;
+        struct node_data *n = bpf_obj_new(typeof(*n)); /* ACQUIRED */
+
+        bpf_spin_lock(&lock);
+
+        bpf_rbtree_add(&tree, n); /* PASSED */
+        x = n->data;
+        n->data = 42;
+
+        bpf_spin_unlock(&lock);
+
+Both the read from and write to ``n->data`` would be rejected. The verifier
+can do better, though, by taking advantage of two details:
+
+  * Graph data structure APIs can only be used when the ``bpf_spin_lock``
+    associated with the graph root is held
+
+  * Both graph data structures have pointer stability
+
+     * Because graph nodes are allocated with ``bpf_obj_new`` and
+       adding / removing from the root involves fiddling with the
+       ``bpf_{list,rb}_node`` field of the node struct, a graph node will
+       remain at the same address after either operation.
+
+Because the associated ``bpf_spin_lock`` must be held by any program adding
+or removing, if we're in the critical section bounded by that lock, we know
+that no other program can add or remove until the end of the critical section.
+This combined with pointer stability means that, until the critical section
+ends, we can safely access the graph node through ``n`` even after it was used
+to pass ownership.
+
+The verifier considers such a reference a *non-owning reference*. The ref
+returned by ``bpf_obj_new`` is accordingly considered an *owning reference*.
+Both terms currently only have meaning in the context of graph nodes and API.
+
+**Details**
+
+Let's enumerate the properties of both types of references.
+
+*owning reference*
+
+  * This reference controls the lifetime of the pointee
+
+  * Ownership of pointee must be 'released' by passing it to some graph API
+    kfunc, or via ``bpf_obj_drop``, which ``free``'s the pointee
+
+    * If not released before program ends, verifier considers program invalid
+
+  * Access to the pointee's memory will not page fault
+
+*non-owning reference*
+
+  * This reference does not own the pointee
+
+     * It cannot be used to add the graph node to a graph root, nor ``free``'d via
+       ``bpf_obj_drop``
+
+  * No explicit control of lifetime, but can infer valid lifetime based on
+    non-owning ref existence (see explanation below)
+
+  * Access to the pointee's memory will not page fault
+
+From verifier's perspective non-owning references can only exist
+between spin_lock and spin_unlock. Why? After spin_unlock another program
+can do arbitrary operations on the data structure like removing and ``free``-ing
+via bpf_obj_drop. A non-owning ref to some chunk of memory that was remove'd,
+``free``'d, and reused via bpf_obj_new would point to an entirely different thing.
+Or the memory could go away.
+
+To prevent this logic violation all non-owning references are invalidated by the
+verifier after a critical section ends. This is necessary to ensure the "will
+not page fault" property of non-owning references. So if the verifier hasn't
+invalidated a non-owning ref, accessing it will not page fault.
+
+Currently ``bpf_obj_drop`` is not allowed in the critical section, so
+if there's a valid non-owning ref, we must be in a critical section, and can
+conclude that the ref's memory hasn't been dropped-and- ``free``'d or
+dropped-and-reused.
+
+Any reference to a node that is in an rbtree _must_ be non-owning, since
+the tree has control of the pointee's lifetime. Similarly, any ref to a node
+that isn't in rbtree _must_ be owning. This results in a nice property:
+graph API add / remove implementations don't need to check if a node
+has already been added (or already removed), as the ownership model
+allows the verifier to prevent such a state from being valid by simply checking
+types.
+
+However, pointer aliasing poses an issue for the above "nice property".
+Consider the following example:
+
+.. code-block:: c
+
+        struct node_data *n, *m, *o, *p;
+        n = bpf_obj_new(typeof(*n));     /* 1 */
+
+        bpf_spin_lock(&lock);
+
+        bpf_rbtree_add(&tree, n);        /* 2 */
+        m = bpf_rbtree_first(&tree);     /* 3 */
+
+        o = bpf_rbtree_remove(&tree, n); /* 4 */
+        p = bpf_rbtree_remove(&tree, m); /* 5 */
+
+        bpf_spin_unlock(&lock);
+
+        bpf_obj_drop(o);
+        bpf_obj_drop(p); /* 6 */
+
+Assume the tree is empty before this program runs. If we track verifier state
+changes here using numbers in above comments:
+
+  1) n is an owning reference
+
+  2) n is a non-owning reference, it's been added to the tree
+
+  3) n and m are non-owning references, they both point to the same node
+
+  4) o is an owning reference, n and m non-owning, all point to same node
+
+  5) o and p are owning, n and m non-owning, all point to the same node
+
+  6) a double-free has occurred, since o and p point to same node and o was
+     ``free``'d in previous statement
+
+States 4 and 5 violate our "nice property", as there are non-owning refs to
+a node which is not in an rbtree. Statement 5 will try to remove a node which
+has already been removed as a result of this violation. State 6 is a dangerous
+double-free.
+
+At a minimum we should prevent state 6 from being possible. If we can't also
+prevent state 5 then we must abandon our "nice property" and check whether a
+node has already been removed at runtime.
+
+We prevent both by generalizing the "invalidate non-owning references" behavior
+of ``bpf_spin_unlock`` and doing similar invalidation after
+``bpf_rbtree_remove``. The logic here being that any graph API kfunc which:
+
+  * takes an arbitrary node argument
+
+  * removes it from the data structure
+
+  * returns an owning reference to the removed node
+
+May result in a state where some other non-owning reference points to the same
+node. So ``remove``-type kfuncs must be considered a non-owning reference
+invalidation point as well.