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/admin-guide/tainted-kernels.rst | 184 ++++++++++++++++++++++++++ 1 file changed, 184 insertions(+) create mode 100644 Documentation/admin-guide/tainted-kernels.rst (limited to 'Documentation/admin-guide/tainted-kernels.rst') diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst new file mode 100644 index 000000000..92a8a07f5 --- /dev/null +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -0,0 +1,184 @@ +Tainted kernels +--------------- + +The kernel will mark itself as 'tainted' when something occurs that might be +relevant later when investigating problems. Don't worry too much about this, +most of the time it's not a problem to run a tainted kernel; the information is +mainly of interest once someone wants to investigate some problem, as its real +cause might be the event that got the kernel tainted. That's why bug reports +from tainted kernels will often be ignored by developers, hence try to reproduce +problems with an untainted kernel. + +Note the kernel will remain tainted even after you undo what caused the taint +(i.e. unload a proprietary kernel module), to indicate the kernel remains not +trustworthy. That's also why the kernel will print the tainted state when it +notices an internal problem (a 'kernel bug'), a recoverable error +('kernel oops') or a non-recoverable error ('kernel panic') and writes debug +information about this to the logs ``dmesg`` outputs. It's also possible to +check the tainted state at runtime through a file in ``/proc/``. + + +Tainted flag in bugs, oops or panics messages +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +You find the tainted state near the top in a line starting with 'CPU:'; if or +why the kernel was tainted is shown after the Process ID ('PID:') and a shortened +name of the command ('Comm:') that triggered the event:: + + BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 + Oops: 0002 [#1] SMP PTI + CPU: 0 PID: 4424 Comm: insmod Tainted: P W O 4.20.0-0.rc6.fc30 #1 + Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 + RIP: 0010:my_oops_init+0x13/0x1000 [kpanic] + [...] + +You'll find a 'Not tainted: ' there if the kernel was not tainted at the +time of the event; if it was, then it will print 'Tainted: ' and characters +either letters or blanks. In above example it looks like this:: + + Tainted: P W O + +The meaning of those characters is explained in the table below. In this case +the kernel got tainted earlier because a proprietary Module (``P``) was loaded, +a warning occurred (``W``), and an externally-built module was loaded (``O``). +To decode other letters use the table below. + + +Decoding tainted state at runtime +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +At runtime, you can query the tainted state by reading +``cat /proc/sys/kernel/tainted``. If that returns ``0``, the kernel is not +tainted; any other number indicates the reasons why it is. The easiest way to +decode that number is the script ``tools/debugging/kernel-chktaint``, which your +distribution might ship as part of a package called ``linux-tools`` or +``kernel-tools``; if it doesn't you can download the script from +`git.kernel.org `_ +and execute it with ``sh kernel-chktaint``, which would print something like +this on the machine that had the statements in the logs that were quoted earlier:: + + Kernel is Tainted for following reasons: + * Proprietary module was loaded (#0) + * Kernel issued warning (#9) + * Externally-built ('out-of-tree') module was loaded (#12) + See Documentation/admin-guide/tainted-kernels.rst in the Linux kernel or + https://www.kernel.org/doc/html/latest/admin-guide/tainted-kernels.html for + a more details explanation of the various taint flags. + Raw taint value as int/string: 4609/'P W O ' + +You can try to decode the number yourself. That's easy if there was only one +reason that got your kernel tainted, as in this case you can find the number +with the table below. If there were multiple reasons you need to decode the +number, as it is a bitfield, where each bit indicates the absence or presence of +a particular type of taint. It's best to leave that to the aforementioned +script, but if you need something quick you can use this shell command to check +which bits are set:: + + $ for i in $(seq 18); do echo $(($i-1)) $(($(cat /proc/sys/kernel/tainted)>>($i-1)&1));done + +Table for decoding tainted state +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +=== === ====== ======================================================== +Bit Log Number Reason that got the kernel tainted +=== === ====== ======================================================== + 0 G/P 1 proprietary module was loaded + 1 _/F 2 module was force loaded + 2 _/S 4 kernel running on an out of specification system + 3 _/R 8 module was force unloaded + 4 _/M 16 processor reported a Machine Check Exception (MCE) + 5 _/B 32 bad page referenced or some unexpected page flags + 6 _/U 64 taint requested by userspace application + 7 _/D 128 kernel died recently, i.e. there was an OOPS or BUG + 8 _/A 256 ACPI table overridden by user + 9 _/W 512 kernel issued warning + 10 _/C 1024 staging driver was loaded + 11 _/I 2048 workaround for bug in platform firmware applied + 12 _/O 4096 externally-built ("out-of-tree") module was loaded + 13 _/E 8192 unsigned module was loaded + 14 _/L 16384 soft lockup occurred + 15 _/K 32768 kernel has been live patched + 16 _/X 65536 auxiliary taint, defined for and used by distros + 17 _/T 131072 kernel was built with the struct randomization plugin + 18 _/N 262144 an in-kernel test has been run +=== === ====== ======================================================== + +Note: The character ``_`` is representing a blank in this table to make reading +easier. + +More detailed explanation for tainting +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + + 0) ``G`` if all modules loaded have a GPL or compatible license, ``P`` if + any proprietary module has been loaded. Modules without a + MODULE_LICENSE or with a MODULE_LICENSE that is not recognised by + insmod as GPL compatible are assumed to be proprietary. + + 1) ``F`` if any module was force loaded by ``insmod -f``, ``' '`` if all + modules were loaded normally. + + 2) ``S`` if the kernel is running on a processor or system that is out of + specification: hardware has been put into an unsupported configuration, + therefore proper execution cannot be guaranteed. + Kernel will be tainted if, for example: + + - on x86: PAE is forced through forcepae on intel CPUs (such as Pentium M) + which do not report PAE but may have a functional implementation, an SMP + kernel is running on non officially capable SMP Athlon CPUs, MSRs are + being poked at from userspace. + - on arm: kernel running on certain CPUs (such as Keystone 2) without + having certain kernel features enabled. + - on arm64: there are mismatched hardware features between CPUs, the + bootloader has booted CPUs in different modes. + - certain drivers are being used on non supported architectures (such as + scsi/snic on something else than x86_64, scsi/ips on non + x86/x86_64/itanium, have broken firmware settings for the + irqchip/irq-gic on arm64 ...). + - x86/x86_64: Microcode late loading is dangerous and will result in + tainting the kernel. It requires that all CPUs rendezvous to make sure + the update happens when the system is as quiescent as possible. However, + a higher priority MCE/SMI/NMI can move control flow away from that + rendezvous and interrupt the update, which can be detrimental to the + machine. + + 3) ``R`` if a module was force unloaded by ``rmmod -f``, ``' '`` if all + modules were unloaded normally. + + 4) ``M`` if any processor has reported a Machine Check Exception, + ``' '`` if no Machine Check Exceptions have occurred. + + 5) ``B`` If a page-release function has found a bad page reference or some + unexpected page flags. This indicates a hardware problem or a kernel bug; + there should be other information in the log indicating why this tainting + occurred. + + 6) ``U`` if a user or user application specifically requested that the + Tainted flag be set, ``' '`` otherwise. + + 7) ``D`` if the kernel has died recently, i.e. there was an OOPS or BUG. + + 8) ``A`` if an ACPI table has been overridden. + + 9) ``W`` if a warning has previously been issued by the kernel. + (Though some warnings may set more specific taint flags.) + + 10) ``C`` if a staging driver has been loaded. + + 11) ``I`` if the kernel is working around a severe bug in the platform + firmware (BIOS or similar). + + 12) ``O`` if an externally-built ("out-of-tree") module has been loaded. + + 13) ``E`` if an unsigned module has been loaded in a kernel supporting + module signature. + + 14) ``L`` if a soft lockup has previously occurred on the system. + + 15) ``K`` if the kernel has been live patched. + + 16) ``X`` Auxiliary taint, defined for and used by Linux distributors. + + 17) ``T`` Kernel was build with the randstruct plugin, which can intentionally + produce extremely unusual kernel structure layouts (even performance + pathological ones), which is important to know when debugging. Set at + build time. -- cgit v1.2.3