From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- Documentation/core-api/debug-objects.rst | 310 +++++++++++++++++++++++++++++++ 1 file changed, 310 insertions(+) create mode 100644 Documentation/core-api/debug-objects.rst (limited to 'Documentation/core-api/debug-objects.rst') diff --git a/Documentation/core-api/debug-objects.rst b/Documentation/core-api/debug-objects.rst new file mode 100644 index 000000000..ac926fd55 --- /dev/null +++ b/Documentation/core-api/debug-objects.rst @@ -0,0 +1,310 @@ +============================================ +The object-lifetime debugging infrastructure +============================================ + +:Author: Thomas Gleixner + +Introduction +============ + +debugobjects is a generic infrastructure to track the life time of +kernel objects and validate the operations on those. + +debugobjects is useful to check for the following error patterns: + +- Activation of uninitialized objects + +- Initialization of active objects + +- Usage of freed/destroyed objects + +debugobjects is not changing the data structure of the real object so it +can be compiled in with a minimal runtime impact and enabled on demand +with a kernel command line option. + +Howto use debugobjects +====================== + +A kernel subsystem needs to provide a data structure which describes the +object type and add calls into the debug code at appropriate places. The +data structure to describe the object type needs at minimum the name of +the object type. Optional functions can and should be provided to fixup +detected problems so the kernel can continue to work and the debug +information can be retrieved from a live system instead of hard core +debugging with serial consoles and stack trace transcripts from the +monitor. + +The debug calls provided by debugobjects are: + +- debug_object_init + +- debug_object_init_on_stack + +- debug_object_activate + +- debug_object_deactivate + +- debug_object_destroy + +- debug_object_free + +- debug_object_assert_init + +Each of these functions takes the address of the real object and a +pointer to the object type specific debug description structure. + +Each detected error is reported in the statistics and a limited number +of errors are printk'ed including a full stack trace. + +The statistics are available via /sys/kernel/debug/debug_objects/stats. +They provide information about the number of warnings and the number of +successful fixups along with information about the usage of the internal +tracking objects and the state of the internal tracking objects pool. + +Debug functions +=============== + +.. kernel-doc:: lib/debugobjects.c + :functions: debug_object_init + +This function is called whenever the initialization function of a real +object is called. + +When the real object is already tracked by debugobjects it is checked, +whether the object can be initialized. Initializing is not allowed for +active and destroyed objects. When debugobjects detects an error, then +it calls the fixup_init function of the object type description +structure if provided by the caller. The fixup function can correct the +problem before the real initialization of the object happens. E.g. it +can deactivate an active object in order to prevent damage to the +subsystem. + +When the real object is not yet tracked by debugobjects, debugobjects +allocates a tracker object for the real object and sets the tracker +object state to ODEBUG_STATE_INIT. It verifies that the object is not +on the callers stack. If it is on the callers stack then a limited +number of warnings including a full stack trace is printk'ed. The +calling code must use debug_object_init_on_stack() and remove the +object before leaving the function which allocated it. See next section. + +.. kernel-doc:: lib/debugobjects.c + :functions: debug_object_init_on_stack + +This function is called whenever the initialization function of a real +object which resides on the stack is called. + +When the real object is already tracked by debugobjects it is checked, +whether the object can be initialized. Initializing is not allowed for +active and destroyed objects. When debugobjects detects an error, then +it calls the fixup_init function of the object type description +structure if provided by the caller. The fixup function can correct the +problem before the real initialization of the object happens. E.g. it +can deactivate an active object in order to prevent damage to the +subsystem. + +When the real object is not yet tracked by debugobjects debugobjects +allocates a tracker object for the real object and sets the tracker +object state to ODEBUG_STATE_INIT. It verifies that the object is on +the callers stack. + +An object which is on the stack must be removed from the tracker by +calling debug_object_free() before the function which allocates the +object returns. Otherwise we keep track of stale objects. + +.. kernel-doc:: lib/debugobjects.c + :functions: debug_object_activate + +This function is called whenever the activation function of a real +object is called. + +When the real object is already tracked by debugobjects it is checked, +whether the object can be activated. Activating is not allowed for +active and destroyed objects. When debugobjects detects an error, then +it calls the fixup_activate function of the object type description +structure if provided by the caller. The fixup function can correct the +problem before the real activation of the object happens. E.g. it can +deactivate an active object in order to prevent damage to the subsystem. + +When the real object is not yet tracked by debugobjects then the +fixup_activate function is called if available. This is necessary to +allow the legitimate activation of statically allocated and initialized +objects. The fixup function checks whether the object is valid and calls +the debug_objects_init() function to initialize the tracking of this +object. + +When the activation is legitimate, then the state of the associated +tracker object is set to ODEBUG_STATE_ACTIVE. + + +.. kernel-doc:: lib/debugobjects.c + :functions: debug_object_deactivate + +This function is called whenever the deactivation function of a real +object is called. + +When the real object is tracked by debugobjects it is checked, whether +the object can be deactivated. Deactivating is not allowed for untracked +or destroyed objects. + +When the deactivation is legitimate, then the state of the associated +tracker object is set to ODEBUG_STATE_INACTIVE. + +.. kernel-doc:: lib/debugobjects.c + :functions: debug_object_destroy + +This function is called to mark an object destroyed. This is useful to +prevent the usage of invalid objects, which are still available in +memory: either statically allocated objects or objects which are freed +later. + +When the real object is tracked by debugobjects it is checked, whether +the object can be destroyed. Destruction is not allowed for active and +destroyed objects. When debugobjects detects an error, then it calls the +fixup_destroy function of the object type description structure if +provided by the caller. The fixup function can correct the problem +before the real destruction of the object happens. E.g. it can +deactivate an active object in order to prevent damage to the subsystem. + +When the destruction is legitimate, then the state of the associated +tracker object is set to ODEBUG_STATE_DESTROYED. + +.. kernel-doc:: lib/debugobjects.c + :functions: debug_object_free + +This function is called before an object is freed. + +When the real object is tracked by debugobjects it is checked, whether +the object can be freed. Free is not allowed for active objects. When +debugobjects detects an error, then it calls the fixup_free function of +the object type description structure if provided by the caller. The +fixup function can correct the problem before the real free of the +object happens. E.g. it can deactivate an active object in order to +prevent damage to the subsystem. + +Note that debug_object_free removes the object from the tracker. Later +usage of the object is detected by the other debug checks. + + +.. kernel-doc:: lib/debugobjects.c + :functions: debug_object_assert_init + +This function is called to assert that an object has been initialized. + +When the real object is not tracked by debugobjects, it calls +fixup_assert_init of the object type description structure provided by +the caller, with the hardcoded object state ODEBUG_NOT_AVAILABLE. The +fixup function can correct the problem by calling debug_object_init +and other specific initializing functions. + +When the real object is already tracked by debugobjects it is ignored. + +Fixup functions +=============== + +Debug object type description structure +--------------------------------------- + +.. kernel-doc:: include/linux/debugobjects.h + :internal: + +fixup_init +----------- + +This function is called from the debug code whenever a problem in +debug_object_init is detected. The function takes the address of the +object and the state which is currently recorded in the tracker. + +Called from debug_object_init when the object state is: + +- ODEBUG_STATE_ACTIVE + +The function returns true when the fixup was successful, otherwise +false. The return value is used to update the statistics. + +Note, that the function needs to call the debug_object_init() function +again, after the damage has been repaired in order to keep the state +consistent. + +fixup_activate +--------------- + +This function is called from the debug code whenever a problem in +debug_object_activate is detected. + +Called from debug_object_activate when the object state is: + +- ODEBUG_STATE_NOTAVAILABLE + +- ODEBUG_STATE_ACTIVE + +The function returns true when the fixup was successful, otherwise +false. The return value is used to update the statistics. + +Note that the function needs to call the debug_object_activate() +function again after the damage has been repaired in order to keep the +state consistent. + +The activation of statically initialized objects is a special case. When +debug_object_activate() has no tracked object for this object address +then fixup_activate() is called with object state +ODEBUG_STATE_NOTAVAILABLE. The fixup function needs to check whether +this is a legitimate case of a statically initialized object or not. In +case it is it calls debug_object_init() and debug_object_activate() +to make the object known to the tracker and marked active. In this case +the function should return false because this is not a real fixup. + +fixup_destroy +-------------- + +This function is called from the debug code whenever a problem in +debug_object_destroy is detected. + +Called from debug_object_destroy when the object state is: + +- ODEBUG_STATE_ACTIVE + +The function returns true when the fixup was successful, otherwise +false. The return value is used to update the statistics. + +fixup_free +----------- + +This function is called from the debug code whenever a problem in +debug_object_free is detected. Further it can be called from the debug +checks in kfree/vfree, when an active object is detected from the +debug_check_no_obj_freed() sanity checks. + +Called from debug_object_free() or debug_check_no_obj_freed() when +the object state is: + +- ODEBUG_STATE_ACTIVE + +The function returns true when the fixup was successful, otherwise +false. The return value is used to update the statistics. + +fixup_assert_init +------------------- + +This function is called from the debug code whenever a problem in +debug_object_assert_init is detected. + +Called from debug_object_assert_init() with a hardcoded state +ODEBUG_STATE_NOTAVAILABLE when the object is not found in the debug +bucket. + +The function returns true when the fixup was successful, otherwise +false. The return value is used to update the statistics. + +Note, this function should make sure debug_object_init() is called +before returning. + +The handling of statically initialized objects is a special case. The +fixup function should check if this is a legitimate case of a statically +initialized object or not. In this case only debug_object_init() +should be called to make the object known to the tracker. Then the +function should return false because this is not a real fixup. + +Known Bugs And Assumptions +========================== + +None (knock on wood). -- cgit v1.2.3