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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/bpf/drgn.rst
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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(). ...
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+.. SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+
+==============
+BPF drgn tools
+==============
+
+drgn scripts is a convenient and easy to use mechanism to retrieve arbitrary
+kernel data structures. drgn is not relying on kernel UAPI to read the data.
+Instead it's reading directly from ``/proc/kcore`` or vmcore and pretty prints
+the data based on DWARF debug information from vmlinux.
+
+This document describes BPF related drgn tools.
+
+See `drgn/tools`_ for all tools available at the moment and `drgn/doc`_ for
+more details on drgn itself.
+
+bpf_inspect.py
+--------------
+
+Description
+===========
+
+`bpf_inspect.py`_ is a tool intended to inspect BPF programs and maps. It can
+iterate over all programs and maps in the system and print basic information
+about these objects, including id, type and name.
+
+The main use-case `bpf_inspect.py`_ covers is to show BPF programs of types
+``BPF_PROG_TYPE_EXT`` and ``BPF_PROG_TYPE_TRACING`` attached to other BPF
+programs via ``freplace``/``fentry``/``fexit`` mechanisms, since there is no
+user-space API to get this information.
+
+Getting started
+===============
+
+List BPF programs (full names are obtained from BTF)::
+
+ % sudo bpf_inspect.py prog
+ 27: BPF_PROG_TYPE_TRACEPOINT tracepoint__tcp__tcp_send_reset
+ 4632: BPF_PROG_TYPE_CGROUP_SOCK_ADDR tw_ipt_bind
+ 49464: BPF_PROG_TYPE_RAW_TRACEPOINT raw_tracepoint__sched_process_exit
+
+List BPF maps::
+
+ % sudo bpf_inspect.py map
+ 2577: BPF_MAP_TYPE_HASH tw_ipt_vips
+ 4050: BPF_MAP_TYPE_STACK_TRACE stack_traces
+ 4069: BPF_MAP_TYPE_PERCPU_ARRAY ned_dctcp_cntr
+
+Find BPF programs attached to BPF program ``test_pkt_access``::
+
+ % sudo bpf_inspect.py p | grep test_pkt_access
+ 650: BPF_PROG_TYPE_SCHED_CLS test_pkt_access
+ 654: BPF_PROG_TYPE_TRACING test_main linked:[650->25: BPF_TRAMP_FEXIT test_pkt_access->test_pkt_access()]
+ 655: BPF_PROG_TYPE_TRACING test_subprog1 linked:[650->29: BPF_TRAMP_FEXIT test_pkt_access->test_pkt_access_subprog1()]
+ 656: BPF_PROG_TYPE_TRACING test_subprog2 linked:[650->31: BPF_TRAMP_FEXIT test_pkt_access->test_pkt_access_subprog2()]
+ 657: BPF_PROG_TYPE_TRACING test_subprog3 linked:[650->21: BPF_TRAMP_FEXIT test_pkt_access->test_pkt_access_subprog3()]
+ 658: BPF_PROG_TYPE_EXT new_get_skb_len linked:[650->16: BPF_TRAMP_REPLACE test_pkt_access->get_skb_len()]
+ 659: BPF_PROG_TYPE_EXT new_get_skb_ifindex linked:[650->23: BPF_TRAMP_REPLACE test_pkt_access->get_skb_ifindex()]
+ 660: BPF_PROG_TYPE_EXT new_get_constant linked:[650->19: BPF_TRAMP_REPLACE test_pkt_access->get_constant()]
+
+It can be seen that there is a program ``test_pkt_access``, id 650 and there
+are multiple other tracing and ext programs attached to functions in
+``test_pkt_access``.
+
+For example the line::
+
+ 658: BPF_PROG_TYPE_EXT new_get_skb_len linked:[650->16: BPF_TRAMP_REPLACE test_pkt_access->get_skb_len()]
+
+, means that BPF program id 658, type ``BPF_PROG_TYPE_EXT``, name
+``new_get_skb_len`` replaces (``BPF_TRAMP_REPLACE``) function ``get_skb_len()``
+that has BTF id 16 in BPF program id 650, name ``test_pkt_access``.
+
+Getting help:
+
+.. code-block:: none
+
+ % sudo bpf_inspect.py
+ usage: bpf_inspect.py [-h] {prog,p,map,m} ...
+
+ drgn script to list BPF programs or maps and their properties
+ unavailable via kernel API.
+
+ See https://github.com/osandov/drgn/ for more details on drgn.
+
+ optional arguments:
+ -h, --help show this help message and exit
+
+ subcommands:
+ {prog,p,map,m}
+ prog (p) list BPF programs
+ map (m) list BPF maps
+
+Customization
+=============
+
+The script is intended to be customized by developers to print relevant
+information about BPF programs, maps and other objects.
+
+For example, to print ``struct bpf_prog_aux`` for BPF program id 53077:
+
+.. code-block:: none
+
+ % git diff
+ diff --git a/tools/bpf_inspect.py b/tools/bpf_inspect.py
+ index 650e228..aea2357 100755
+ --- a/tools/bpf_inspect.py
+ +++ b/tools/bpf_inspect.py
+ @@ -112,7 +112,9 @@ def list_bpf_progs(args):
+ if linked:
+ linked = f" linked:[{linked}]"
+
+ - print(f"{id_:>6}: {type_:32} {name:32} {linked}")
+ + if id_ == 53077:
+ + print(f"{id_:>6}: {type_:32} {name:32}")
+ + print(f"{bpf_prog.aux}")
+
+
+ def list_bpf_maps(args):
+
+It produces the output::
+
+ % sudo bpf_inspect.py p
+ 53077: BPF_PROG_TYPE_XDP tw_xdp_policer
+ *(struct bpf_prog_aux *)0xffff8893fad4b400 = {
+ .refcnt = (atomic64_t){
+ .counter = (long)58,
+ },
+ .used_map_cnt = (u32)1,
+ .max_ctx_offset = (u32)8,
+ .max_pkt_offset = (u32)15,
+ .max_tp_access = (u32)0,
+ .stack_depth = (u32)8,
+ .id = (u32)53077,
+ .func_cnt = (u32)0,
+ .func_idx = (u32)0,
+ .attach_btf_id = (u32)0,
+ .linked_prog = (struct bpf_prog *)0x0,
+ .verifier_zext = (bool)0,
+ .offload_requested = (bool)0,
+ .attach_btf_trace = (bool)0,
+ .func_proto_unreliable = (bool)0,
+ .trampoline_prog_type = (enum bpf_tramp_prog_type)BPF_TRAMP_FENTRY,
+ .trampoline = (struct bpf_trampoline *)0x0,
+ .tramp_hlist = (struct hlist_node){
+ .next = (struct hlist_node *)0x0,
+ .pprev = (struct hlist_node **)0x0,
+ },
+ .attach_func_proto = (const struct btf_type *)0x0,
+ .attach_func_name = (const char *)0x0,
+ .func = (struct bpf_prog **)0x0,
+ .jit_data = (void *)0x0,
+ .poke_tab = (struct bpf_jit_poke_descriptor *)0x0,
+ .size_poke_tab = (u32)0,
+ .ksym_tnode = (struct latch_tree_node){
+ .node = (struct rb_node [2]){
+ {
+ .__rb_parent_color = (unsigned long)18446612956263126665,
+ .rb_right = (struct rb_node *)0x0,
+ .rb_left = (struct rb_node *)0xffff88a0be3d0088,
+ },
+ {
+ .__rb_parent_color = (unsigned long)18446612956263126689,
+ .rb_right = (struct rb_node *)0x0,
+ .rb_left = (struct rb_node *)0xffff88a0be3d00a0,
+ },
+ },
+ },
+ .ksym_lnode = (struct list_head){
+ .next = (struct list_head *)0xffff88bf481830b8,
+ .prev = (struct list_head *)0xffff888309f536b8,
+ },
+ .ops = (const struct bpf_prog_ops *)xdp_prog_ops+0x0 = 0xffffffff820fa350,
+ .used_maps = (struct bpf_map **)0xffff889ff795de98,
+ .prog = (struct bpf_prog *)0xffffc9000cf2d000,
+ .user = (struct user_struct *)root_user+0x0 = 0xffffffff82444820,
+ .load_time = (u64)2408348759285319,
+ .cgroup_storage = (struct bpf_map *[2]){},
+ .name = (char [16])"tw_xdp_policer",
+ .security = (void *)0xffff889ff795d548,
+ .offload = (struct bpf_prog_offload *)0x0,
+ .btf = (struct btf *)0xffff8890ce6d0580,
+ .func_info = (struct bpf_func_info *)0xffff889ff795d240,
+ .func_info_aux = (struct bpf_func_info_aux *)0xffff889ff795de20,
+ .linfo = (struct bpf_line_info *)0xffff888a707afc00,
+ .jited_linfo = (void **)0xffff8893fad48600,
+ .func_info_cnt = (u32)1,
+ .nr_linfo = (u32)37,
+ .linfo_idx = (u32)0,
+ .num_exentries = (u32)0,
+ .extable = (struct exception_table_entry *)0xffffffffa032d950,
+ .stats = (struct bpf_prog_stats *)0x603fe3a1f6d0,
+ .work = (struct work_struct){
+ .data = (atomic_long_t){
+ .counter = (long)0,
+ },
+ .entry = (struct list_head){
+ .next = (struct list_head *)0x0,
+ .prev = (struct list_head *)0x0,
+ },
+ .func = (work_func_t)0x0,
+ },
+ .rcu = (struct callback_head){
+ .next = (struct callback_head *)0x0,
+ .func = (void (*)(struct callback_head *))0x0,
+ },
+ }
+
+
+.. Links
+.. _drgn/doc: https://drgn.readthedocs.io/en/latest/
+.. _drgn/tools: https://github.com/osandov/drgn/tree/master/tools
+.. _bpf_inspect.py:
+ https://github.com/osandov/drgn/blob/master/tools/bpf_inspect.py