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(). ... --- tools/memory-model/litmus-tests/README | 261 +++++++++++++++++++++++++++++++++ 1 file changed, 261 insertions(+) create mode 100644 tools/memory-model/litmus-tests/README (limited to 'tools/memory-model/litmus-tests/README') diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README new file mode 100644 index 000000000..d311a0ff1 --- /dev/null +++ b/tools/memory-model/litmus-tests/README @@ -0,0 +1,261 @@ +============ +LITMUS TESTS +============ + +CoRR+poonceonce+Once.litmus + Test of read-read coherence, that is, whether or not two + successive reads from the same variable are ordered. + +CoRW+poonceonce+Once.litmus + Test of read-write coherence, that is, whether or not a read + from a given variable followed by a write to that same variable + are ordered. + +CoWR+poonceonce+Once.litmus + Test of write-read coherence, that is, whether or not a write + to a given variable followed by a read from that same variable + are ordered. + +CoWW+poonceonce.litmus + Test of write-write coherence, that is, whether or not two + successive writes to the same variable are ordered. + +IRIW+fencembonceonces+OnceOnce.litmus + Test of independent reads from independent writes with smp_mb() + between each pairs of reads. In other words, is smp_mb() + sufficient to cause two different reading processes to agree on + the order of a pair of writes, where each write is to a different + variable by a different process? This litmus test is forbidden + by LKMM's propagation rule. + +IRIW+poonceonces+OnceOnce.litmus + Test of independent reads from independent writes with nothing + between each pairs of reads. In other words, is anything at all + needed to cause two different reading processes to agree on the + order of a pair of writes, where each write is to a different + variable by a different process? + +ISA2+pooncelock+pooncelock+pombonce.litmus + Tests whether the ordering provided by a lock-protected S + litmus test is visible to an external process whose accesses are + separated by smp_mb(). This addition of an external process to + S is otherwise known as ISA2. + +ISA2+poonceonces.litmus + As below, but with store-release replaced with WRITE_ONCE() + and load-acquire replaced with READ_ONCE(). + +ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus + Can a release-acquire chain order a prior store against + a later load? + +LB+fencembonceonce+ctrlonceonce.litmus + Does a control dependency and an smp_mb() suffice for the + load-buffering litmus test, where each process reads from one + of two variables then writes to the other? + +LB+poacquireonce+pooncerelease.litmus + Does a release-acquire pair suffice for the load-buffering + litmus test, where each process reads from one of two variables then + writes to the other? + +LB+poonceonces.litmus + As above, but with store-release replaced with WRITE_ONCE() + and load-acquire replaced with READ_ONCE(). + +LB+unlocklockonceonce+poacquireonce.litmus + Does a unlock+lock pair provides ordering guarantee between a + load and a store? + +MP+onceassign+derefonce.litmus + As below, but with rcu_assign_pointer() and an rcu_dereference(). + +MP+polockmbonce+poacquiresilsil.litmus + Protect the access with a lock and an smp_mb__after_spinlock() + in one process, and use an acquire load followed by a pair of + spin_is_locked() calls in the other process. + +MP+polockonce+poacquiresilsil.litmus + Protect the access with a lock in one process, and use an + acquire load followed by a pair of spin_is_locked() calls + in the other process. + +MP+polocks.litmus + As below, but with the second access of the writer process + and the first access of reader process protected by a lock. + +MP+poonceonces.litmus + As below, but without the smp_rmb() and smp_wmb(). + +MP+pooncerelease+poacquireonce.litmus + As below, but with a release-acquire chain. + +MP+porevlocks.litmus + As below, but with the first access of the writer process + and the second access of reader process protected by a lock. + +MP+unlocklockonceonce+fencermbonceonce.litmus + Does a unlock+lock pair provides ordering guarantee between a + store and another store? + +MP+fencewmbonceonce+fencermbonceonce.litmus + Does a smp_wmb() (between the stores) and an smp_rmb() (between + the loads) suffice for the message-passing litmus test, where one + process writes data and then a flag, and the other process reads + the flag and then the data. (This is similar to the ISA2 tests, + but with two processes instead of three.) + +R+fencembonceonces.litmus + This is the fully ordered (via smp_mb()) version of one of + the classic counterintuitive litmus tests that illustrates the + effects of store propagation delays. + +R+poonceonces.litmus + As above, but without the smp_mb() invocations. + +SB+fencembonceonces.litmus + This is the fully ordered (again, via smp_mb() version of store + buffering, which forms the core of Dekker's mutual-exclusion + algorithm. + +SB+poonceonces.litmus + As above, but without the smp_mb() invocations. + +SB+rfionceonce-poonceonces.litmus + This litmus test demonstrates that LKMM is not fully multicopy + atomic. (Neither is it other multicopy atomic.) This litmus test + also demonstrates the "locations" debugging aid, which designates + additional registers and locations to be printed out in the dump + of final states in the herd7 output. Without the "locations" + statement, only those registers and locations mentioned in the + "exists" clause will be printed. + +S+poonceonces.litmus + As below, but without the smp_wmb() and acquire load. + +S+fencewmbonceonce+poacquireonce.litmus + Can a smp_wmb(), instead of a release, and an acquire order + a prior store against a subsequent store? + +WRC+poonceonces+Once.litmus +WRC+pooncerelease+fencermbonceonce+Once.litmus + These two are members of an extension of the MP litmus-test + class in which the first write is moved to a separate process. + The second is forbidden because smp_store_release() is + A-cumulative in LKMM. + +Z6.0+pooncelock+pooncelock+pombonce.litmus + Is the ordering provided by a spin_unlock() and a subsequent + spin_lock() sufficient to make ordering apparent to accesses + by a process not holding the lock? + +Z6.0+pooncelock+poonceLock+pombonce.litmus + As above, but with smp_mb__after_spinlock() immediately + following the spin_lock(). + +Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus + Is the ordering provided by a release-acquire chain sufficient + to make ordering apparent to accesses by a process that does + not participate in that release-acquire chain? + +A great many more litmus tests are available here: + + https://github.com/paulmckrcu/litmus + +================== +LITMUS TEST NAMING +================== + +Litmus tests are usually named based on their contents, which means that +looking at the name tells you what the litmus test does. The naming +scheme covers litmus tests having a single cycle that passes through +each process exactly once, so litmus tests not fitting this description +are named on an ad-hoc basis. + +The structure of a litmus-test name is the litmus-test class, a plus +sign ("+"), and one string for each process, separated by plus signs. +The end of the name is ".litmus". + +The litmus-test classes may be found in the infamous test6.pdf: +https://www.cl.cam.ac.uk/~pes20/ppc-supplemental/test6.pdf +Each class defines the pattern of accesses and of the variables accessed. +For example, if the one process writes to a pair of variables, and +the other process reads from these same variables, the corresponding +litmus-test class is "MP" (message passing), which may be found on the +left-hand end of the second row of tests on page one of test6.pdf. + +The strings used to identify the actions carried out by each process are +complex due to a desire to have short(er) names. Thus, there is a tool to +generate these strings from a given litmus test's actions. For example, +consider the processes from SB+rfionceonce-poonceonces.litmus: + + P0(int *x, int *y) + { + int r1; + int r2; + + WRITE_ONCE(*x, 1); + r1 = READ_ONCE(*x); + r2 = READ_ONCE(*y); + } + + P1(int *x, int *y) + { + int r3; + int r4; + + WRITE_ONCE(*y, 1); + r3 = READ_ONCE(*y); + r4 = READ_ONCE(*x); + } + +The next step is to construct a space-separated list of descriptors, +interleaving descriptions of the relation between a pair of consecutive +accesses with descriptions of the second access in the pair. + +P0()'s WRITE_ONCE() is read by its first READ_ONCE(), which is a +reads-from link (rf) and internal to the P0() process. This is +"rfi", which is an abbreviation for "reads-from internal". Because +some of the tools string these abbreviations together with space +characters separating processes, the first character is capitalized, +resulting in "Rfi". + +P0()'s second access is a READ_ONCE(), as opposed to (for example) +smp_load_acquire(), so next is "Once". Thus far, we have "Rfi Once". + +P0()'s third access is also a READ_ONCE(), but to y rather than x. +This is related to P0()'s second access by program order ("po"), +to a different variable ("d"), and both accesses are reads ("RR"). +The resulting descriptor is "PodRR". Because P0()'s third access is +READ_ONCE(), we add another "Once" descriptor. + +A from-read ("fre") relation links P0()'s third to P1()'s first +access, and the resulting descriptor is "Fre". P1()'s first access is +WRITE_ONCE(), which as before gives the descriptor "Once". The string +thus far is thus "Rfi Once PodRR Once Fre Once". + +The remainder of P1() is similar to P0(), which means we add +"Rfi Once PodRR Once". Another fre links P1()'s last access to +P0()'s first access, which is WRITE_ONCE(), so we add "Fre Once". +The full string is thus: + + Rfi Once PodRR Once Fre Once Rfi Once PodRR Once Fre Once + +This string can be given to the "norm7" and "classify7" tools to +produce the name: + + $ norm7 -bell linux-kernel.bell \ + Rfi Once PodRR Once Fre Once Rfi Once PodRR Once Fre Once | \ + sed -e 's/:.*//g' + SB+rfionceonce-poonceonces + +Adding the ".litmus" suffix: SB+rfionceonce-poonceonces.litmus + +The descriptors that describe connections between consecutive accesses +within the cycle through a given litmus test can be provided by the herd7 +tool (Rfi, Po, Fre, and so on) or by the linux-kernel.bell file (Once, +Release, Acquire, and so on). + +To see the full list of descriptors, execute the following command: + + $ diyone7 -bell linux-kernel.bell -show edges -- cgit v1.2.3