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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 /tools/bpf/bpftool/Documentation/bpftool-btf.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: (GPL-2.0-only OR BSD-2-Clause)
+
+================
+bpftool-btf
+================
+-------------------------------------------------------------------------------
+tool for inspection of BTF data
+-------------------------------------------------------------------------------
+
+:Manual section: 8
+
+.. include:: substitutions.rst
+
+SYNOPSIS
+========
+
+ **bpftool** [*OPTIONS*] **btf** *COMMAND*
+
+ *OPTIONS* := { |COMMON_OPTIONS| | { **-B** | **--base-btf** } }
+
+ *COMMANDS* := { **dump** | **help** }
+
+BTF COMMANDS
+=============
+
+| **bpftool** **btf** { **show** | **list** } [**id** *BTF_ID*]
+| **bpftool** **btf dump** *BTF_SRC* [**format** *FORMAT*]
+| **bpftool** **btf help**
+|
+| *BTF_SRC* := { **id** *BTF_ID* | **prog** *PROG* | **map** *MAP* [{**key** | **value** | **kv** | **all**}] | **file** *FILE* }
+| *FORMAT* := { **raw** | **c** }
+| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
+| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
+
+DESCRIPTION
+===========
+ **bpftool btf { show | list }** [**id** *BTF_ID*]
+ Show information about loaded BTF objects. If a BTF ID is
+ specified, show information only about given BTF object,
+ otherwise list all BTF objects currently loaded on the
+ system.
+
+ Since Linux 5.8 bpftool is able to discover information about
+ processes that hold open file descriptors (FDs) against BTF
+ objects. On such kernels bpftool will automatically emit this
+ information as well.
+
+ **bpftool btf dump** *BTF_SRC*
+ Dump BTF entries from a given *BTF_SRC*.
+
+ When **id** is specified, BTF object with that ID will be
+ loaded and all its BTF types emitted.
+
+ When **map** is provided, it's expected that map has
+ associated BTF object with BTF types describing key and
+ value. It's possible to select whether to dump only BTF
+ type(s) associated with key (**key**), value (**value**),
+ both key and value (**kv**), or all BTF types present in
+ associated BTF object (**all**). If not specified, **kv**
+ is assumed.
+
+ When **prog** is provided, it's expected that program has
+ associated BTF object with BTF types.
+
+ When specifying *FILE*, an ELF file is expected, containing
+ .BTF section with well-defined BTF binary format data,
+ typically produced by clang or pahole.
+
+ **format** option can be used to override default (raw)
+ output format. Raw (**raw**) or C-syntax (**c**) output
+ formats are supported.
+
+ **bpftool btf help**
+ Print short help message.
+
+OPTIONS
+=======
+ .. include:: common_options.rst
+
+ -B, --base-btf *FILE*
+ Pass a base BTF object. Base BTF objects are typically used
+ with BTF objects for kernel modules. To avoid duplicating
+ all kernel symbols required by modules, BTF objects for
+ modules are "split", they are built incrementally on top of
+ the kernel (vmlinux) BTF object. So the base BTF reference
+ should usually point to the kernel BTF.
+
+ When the main BTF object to process (for example, the
+ module BTF to dump) is passed as a *FILE*, bpftool attempts
+ to autodetect the path for the base object, and passing
+ this option is optional. When the main BTF object is passed
+ through other handles, this option becomes necessary.
+
+EXAMPLES
+========
+**# bpftool btf dump id 1226**
+
+::
+
+ [1] PTR '(anon)' type_id=2
+ [2] STRUCT 'dummy_tracepoint_args' size=16 vlen=2
+ 'pad' type_id=3 bits_offset=0
+ 'sock' type_id=4 bits_offset=64
+ [3] INT 'long long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none)
+ [4] PTR '(anon)' type_id=5
+ [5] FWD 'sock' fwd_kind=union
+
+This gives an example of default output for all supported BTF kinds.
+
+**$ cat prog.c**
+
+::
+
+ struct fwd_struct;
+
+ enum my_enum {
+ VAL1 = 3,
+ VAL2 = 7,
+ };
+
+ typedef struct my_struct my_struct_t;
+
+ struct my_struct {
+ const unsigned int const_int_field;
+ int bitfield_field: 4;
+ char arr_field[16];
+ const struct fwd_struct *restrict fwd_field;
+ enum my_enum enum_field;
+ volatile my_struct_t *typedef_ptr_field;
+ };
+
+ union my_union {
+ int a;
+ struct my_struct b;
+ };
+
+ struct my_struct struct_global_var __attribute__((section("data_sec"))) = {
+ .bitfield_field = 3,
+ .enum_field = VAL1,
+ };
+ int global_var __attribute__((section("data_sec"))) = 7;
+
+ __attribute__((noinline))
+ int my_func(union my_union *arg1, int arg2)
+ {
+ static int static_var __attribute__((section("data_sec"))) = 123;
+ static_var++;
+ return static_var;
+ }
+
+**$ bpftool btf dump file prog.o**
+
+::
+
+ [1] PTR '(anon)' type_id=2
+ [2] UNION 'my_union' size=48 vlen=2
+ 'a' type_id=3 bits_offset=0
+ 'b' type_id=4 bits_offset=0
+ [3] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
+ [4] STRUCT 'my_struct' size=48 vlen=6
+ 'const_int_field' type_id=5 bits_offset=0
+ 'bitfield_field' type_id=3 bits_offset=32 bitfield_size=4
+ 'arr_field' type_id=8 bits_offset=40
+ 'fwd_field' type_id=10 bits_offset=192
+ 'enum_field' type_id=14 bits_offset=256
+ 'typedef_ptr_field' type_id=15 bits_offset=320
+ [5] CONST '(anon)' type_id=6
+ [6] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none)
+ [7] INT 'char' size=1 bits_offset=0 nr_bits=8 encoding=SIGNED
+ [8] ARRAY '(anon)' type_id=7 index_type_id=9 nr_elems=16
+ [9] INT '__ARRAY_SIZE_TYPE__' size=4 bits_offset=0 nr_bits=32 encoding=(none)
+ [10] RESTRICT '(anon)' type_id=11
+ [11] PTR '(anon)' type_id=12
+ [12] CONST '(anon)' type_id=13
+ [13] FWD 'fwd_struct' fwd_kind=union
+ [14] ENUM 'my_enum' size=4 vlen=2
+ 'VAL1' val=3
+ 'VAL2' val=7
+ [15] PTR '(anon)' type_id=16
+ [16] VOLATILE '(anon)' type_id=17
+ [17] TYPEDEF 'my_struct_t' type_id=4
+ [18] FUNC_PROTO '(anon)' ret_type_id=3 vlen=2
+ 'arg1' type_id=1
+ 'arg2' type_id=3
+ [19] FUNC 'my_func' type_id=18
+ [20] VAR 'struct_global_var' type_id=4, linkage=global-alloc
+ [21] VAR 'global_var' type_id=3, linkage=global-alloc
+ [22] VAR 'my_func.static_var' type_id=3, linkage=static
+ [23] DATASEC 'data_sec' size=0 vlen=3
+ type_id=20 offset=0 size=48
+ type_id=21 offset=0 size=4
+ type_id=22 offset=52 size=4
+
+The following commands print BTF types associated with specified map's key,
+value, both key and value, and all BTF types, respectively. By default, both
+key and value types will be printed.
+
+**# bpftool btf dump map id 123 key**
+
+::
+
+ [39] TYPEDEF 'u32' type_id=37
+
+**# bpftool btf dump map id 123 value**
+
+::
+
+ [86] PTR '(anon)' type_id=87
+
+**# bpftool btf dump map id 123 kv**
+
+::
+
+ [39] TYPEDEF 'u32' type_id=37
+ [86] PTR '(anon)' type_id=87
+
+**# bpftool btf dump map id 123 all**
+
+::
+
+ [1] PTR '(anon)' type_id=0
+ .
+ .
+ .
+ [2866] ARRAY '(anon)' type_id=52 index_type_id=51 nr_elems=4
+
+All the standard ways to specify map or program are supported:
+
+**# bpftool btf dump map id 123**
+
+**# bpftool btf dump map pinned /sys/fs/bpf/map_name**
+
+**# bpftool btf dump prog id 456**
+
+**# bpftool btf dump prog tag b88e0a09b1d9759d**
+
+**# bpftool btf dump prog pinned /sys/fs/bpf/prog_name**
+
+|
+| **# bpftool btf dump file /sys/kernel/btf/i2c_smbus**
+| (or)
+| **# I2C_SMBUS_ID=$(bpftool btf show -p | jq '.[] | select(.name=="i2c_smbus").id')**
+| **# bpftool btf dump id ${I2C_SMBUS_ID} -B /sys/kernel/btf/vmlinux**
+
+::
+
+ [104848] STRUCT 'i2c_smbus_alert' size=40 vlen=2
+ 'alert' type_id=393 bits_offset=0
+ 'ara' type_id=56050 bits_offset=256
+ [104849] STRUCT 'alert_data' size=12 vlen=3
+ 'addr' type_id=16 bits_offset=0
+ 'type' type_id=56053 bits_offset=32
+ 'data' type_id=7 bits_offset=64
+ [104850] PTR '(anon)' type_id=104848
+ [104851] PTR '(anon)' type_id=104849
+ [104852] FUNC 'i2c_register_spd' type_id=84745 linkage=static
+ [104853] FUNC 'smbalert_driver_init' type_id=1213 linkage=static
+ [104854] FUNC_PROTO '(anon)' ret_type_id=18 vlen=1
+ 'ara' type_id=56050
+ [104855] FUNC 'i2c_handle_smbus_alert' type_id=104854 linkage=static
+ [104856] FUNC 'smbalert_remove' type_id=104854 linkage=static
+ [104857] FUNC_PROTO '(anon)' ret_type_id=18 vlen=2
+ 'ara' type_id=56050
+ 'id' type_id=56056
+ [104858] FUNC 'smbalert_probe' type_id=104857 linkage=static
+ [104859] FUNC 'smbalert_work' type_id=9695 linkage=static
+ [104860] FUNC 'smbus_alert' type_id=71367 linkage=static
+ [104861] FUNC 'smbus_do_alert' type_id=84827 linkage=static