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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 /kernel/bpf/tnum.c
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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(). ...
Diffstat (limited to 'kernel/bpf/tnum.c')
-rw-r--r--kernel/bpf/tnum.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/kernel/bpf/tnum.c b/kernel/bpf/tnum.c
new file mode 100644
index 000000000..3d7127f43
--- /dev/null
+++ b/kernel/bpf/tnum.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* tnum: tracked (or tristate) numbers
+ *
+ * A tnum tracks knowledge about the bits of a value. Each bit can be either
+ * known (0 or 1), or unknown (x). Arithmetic operations on tnums will
+ * propagate the unknown bits such that the tnum result represents all the
+ * possible results for possible values of the operands.
+ */
+#include <linux/kernel.h>
+#include <linux/tnum.h>
+
+#define TNUM(_v, _m) (struct tnum){.value = _v, .mask = _m}
+/* A completely unknown value */
+const struct tnum tnum_unknown = { .value = 0, .mask = -1 };
+
+struct tnum tnum_const(u64 value)
+{
+ return TNUM(value, 0);
+}
+
+struct tnum tnum_range(u64 min, u64 max)
+{
+ u64 chi = min ^ max, delta;
+ u8 bits = fls64(chi);
+
+ /* special case, needed because 1ULL << 64 is undefined */
+ if (bits > 63)
+ return tnum_unknown;
+ /* e.g. if chi = 4, bits = 3, delta = (1<<3) - 1 = 7.
+ * if chi = 0, bits = 0, delta = (1<<0) - 1 = 0, so we return
+ * constant min (since min == max).
+ */
+ delta = (1ULL << bits) - 1;
+ return TNUM(min & ~delta, delta);
+}
+
+struct tnum tnum_lshift(struct tnum a, u8 shift)
+{
+ return TNUM(a.value << shift, a.mask << shift);
+}
+
+struct tnum tnum_rshift(struct tnum a, u8 shift)
+{
+ return TNUM(a.value >> shift, a.mask >> shift);
+}
+
+struct tnum tnum_arshift(struct tnum a, u8 min_shift, u8 insn_bitness)
+{
+ /* if a.value is negative, arithmetic shifting by minimum shift
+ * will have larger negative offset compared to more shifting.
+ * If a.value is nonnegative, arithmetic shifting by minimum shift
+ * will have larger positive offset compare to more shifting.
+ */
+ if (insn_bitness == 32)
+ return TNUM((u32)(((s32)a.value) >> min_shift),
+ (u32)(((s32)a.mask) >> min_shift));
+ else
+ return TNUM((s64)a.value >> min_shift,
+ (s64)a.mask >> min_shift);
+}
+
+struct tnum tnum_add(struct tnum a, struct tnum b)
+{
+ u64 sm, sv, sigma, chi, mu;
+
+ sm = a.mask + b.mask;
+ sv = a.value + b.value;
+ sigma = sm + sv;
+ chi = sigma ^ sv;
+ mu = chi | a.mask | b.mask;
+ return TNUM(sv & ~mu, mu);
+}
+
+struct tnum tnum_sub(struct tnum a, struct tnum b)
+{
+ u64 dv, alpha, beta, chi, mu;
+
+ dv = a.value - b.value;
+ alpha = dv + a.mask;
+ beta = dv - b.mask;
+ chi = alpha ^ beta;
+ mu = chi | a.mask | b.mask;
+ return TNUM(dv & ~mu, mu);
+}
+
+struct tnum tnum_and(struct tnum a, struct tnum b)
+{
+ u64 alpha, beta, v;
+
+ alpha = a.value | a.mask;
+ beta = b.value | b.mask;
+ v = a.value & b.value;
+ return TNUM(v, alpha & beta & ~v);
+}
+
+struct tnum tnum_or(struct tnum a, struct tnum b)
+{
+ u64 v, mu;
+
+ v = a.value | b.value;
+ mu = a.mask | b.mask;
+ return TNUM(v, mu & ~v);
+}
+
+struct tnum tnum_xor(struct tnum a, struct tnum b)
+{
+ u64 v, mu;
+
+ v = a.value ^ b.value;
+ mu = a.mask | b.mask;
+ return TNUM(v & ~mu, mu);
+}
+
+/* Generate partial products by multiplying each bit in the multiplier (tnum a)
+ * with the multiplicand (tnum b), and add the partial products after
+ * appropriately bit-shifting them. Instead of directly performing tnum addition
+ * on the generated partial products, equivalenty, decompose each partial
+ * product into two tnums, consisting of the value-sum (acc_v) and the
+ * mask-sum (acc_m) and then perform tnum addition on them. The following paper
+ * explains the algorithm in more detail: https://arxiv.org/abs/2105.05398.
+ */
+struct tnum tnum_mul(struct tnum a, struct tnum b)
+{
+ u64 acc_v = a.value * b.value;
+ struct tnum acc_m = TNUM(0, 0);
+
+ while (a.value || a.mask) {
+ /* LSB of tnum a is a certain 1 */
+ if (a.value & 1)
+ acc_m = tnum_add(acc_m, TNUM(0, b.mask));
+ /* LSB of tnum a is uncertain */
+ else if (a.mask & 1)
+ acc_m = tnum_add(acc_m, TNUM(0, b.value | b.mask));
+ /* Note: no case for LSB is certain 0 */
+ a = tnum_rshift(a, 1);
+ b = tnum_lshift(b, 1);
+ }
+ return tnum_add(TNUM(acc_v, 0), acc_m);
+}
+
+/* Note that if a and b disagree - i.e. one has a 'known 1' where the other has
+ * a 'known 0' - this will return a 'known 1' for that bit.
+ */
+struct tnum tnum_intersect(struct tnum a, struct tnum b)
+{
+ u64 v, mu;
+
+ v = a.value | b.value;
+ mu = a.mask & b.mask;
+ return TNUM(v & ~mu, mu);
+}
+
+struct tnum tnum_cast(struct tnum a, u8 size)
+{
+ a.value &= (1ULL << (size * 8)) - 1;
+ a.mask &= (1ULL << (size * 8)) - 1;
+ return a;
+}
+
+bool tnum_is_aligned(struct tnum a, u64 size)
+{
+ if (!size)
+ return true;
+ return !((a.value | a.mask) & (size - 1));
+}
+
+bool tnum_in(struct tnum a, struct tnum b)
+{
+ if (b.mask & ~a.mask)
+ return false;
+ b.value &= ~a.mask;
+ return a.value == b.value;
+}
+
+int tnum_strn(char *str, size_t size, struct tnum a)
+{
+ return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask);
+}
+EXPORT_SYMBOL_GPL(tnum_strn);
+
+int tnum_sbin(char *str, size_t size, struct tnum a)
+{
+ size_t n;
+
+ for (n = 64; n; n--) {
+ if (n < size) {
+ if (a.mask & 1)
+ str[n - 1] = 'x';
+ else if (a.value & 1)
+ str[n - 1] = '1';
+ else
+ str[n - 1] = '0';
+ }
+ a.mask >>= 1;
+ a.value >>= 1;
+ }
+ str[min(size - 1, (size_t)64)] = 0;
+ return 64;
+}
+
+struct tnum tnum_subreg(struct tnum a)
+{
+ return tnum_cast(a, 4);
+}
+
+struct tnum tnum_clear_subreg(struct tnum a)
+{
+ return tnum_lshift(tnum_rshift(a, 32), 32);
+}
+
+struct tnum tnum_const_subreg(struct tnum a, u32 value)
+{
+ return tnum_or(tnum_clear_subreg(a), tnum_const(value));
+}