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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/rcu/tiny.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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 '')
-rw-r--r--kernel/rcu/tiny.c263
1 files changed, 263 insertions, 0 deletions
diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
new file mode 100644
index 000000000..42f7589e5
--- /dev/null
+++ b/kernel/rcu/tiny.c
@@ -0,0 +1,263 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Author: Paul E. McKenney <paulmck@linux.ibm.com>
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ * Documentation/RCU
+ */
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/rcupdate_wait.h>
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/cpu.h>
+#include <linux/prefetch.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include "rcu.h"
+
+/* Global control variables for rcupdate callback mechanism. */
+struct rcu_ctrlblk {
+ struct rcu_head *rcucblist; /* List of pending callbacks (CBs). */
+ struct rcu_head **donetail; /* ->next pointer of last "done" CB. */
+ struct rcu_head **curtail; /* ->next pointer of last CB. */
+ unsigned long gp_seq; /* Grace-period counter. */
+};
+
+/* Definition for rcupdate control block. */
+static struct rcu_ctrlblk rcu_ctrlblk = {
+ .donetail = &rcu_ctrlblk.rcucblist,
+ .curtail = &rcu_ctrlblk.rcucblist,
+ .gp_seq = 0 - 300UL,
+};
+
+void rcu_barrier(void)
+{
+ wait_rcu_gp(call_rcu_hurry);
+}
+EXPORT_SYMBOL(rcu_barrier);
+
+/* Record an rcu quiescent state. */
+void rcu_qs(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (rcu_ctrlblk.donetail != rcu_ctrlblk.curtail) {
+ rcu_ctrlblk.donetail = rcu_ctrlblk.curtail;
+ raise_softirq_irqoff(RCU_SOFTIRQ);
+ }
+ WRITE_ONCE(rcu_ctrlblk.gp_seq, rcu_ctrlblk.gp_seq + 2);
+ local_irq_restore(flags);
+}
+
+/*
+ * Check to see if the scheduling-clock interrupt came from an extended
+ * quiescent state, and, if so, tell RCU about it. This function must
+ * be called from hardirq context. It is normally called from the
+ * scheduling-clock interrupt.
+ */
+void rcu_sched_clock_irq(int user)
+{
+ if (user) {
+ rcu_qs();
+ } else if (rcu_ctrlblk.donetail != rcu_ctrlblk.curtail) {
+ set_tsk_need_resched(current);
+ set_preempt_need_resched();
+ }
+}
+
+/*
+ * Reclaim the specified callback, either by invoking it for non-kfree cases or
+ * freeing it directly (for kfree). Return true if kfreeing, false otherwise.
+ */
+static inline bool rcu_reclaim_tiny(struct rcu_head *head)
+{
+ rcu_callback_t f;
+ unsigned long offset = (unsigned long)head->func;
+
+ rcu_lock_acquire(&rcu_callback_map);
+ if (__is_kvfree_rcu_offset(offset)) {
+ trace_rcu_invoke_kvfree_callback("", head, offset);
+ kvfree((void *)head - offset);
+ rcu_lock_release(&rcu_callback_map);
+ return true;
+ }
+
+ trace_rcu_invoke_callback("", head);
+ f = head->func;
+ WRITE_ONCE(head->func, (rcu_callback_t)0L);
+ f(head);
+ rcu_lock_release(&rcu_callback_map);
+ return false;
+}
+
+/* Invoke the RCU callbacks whose grace period has elapsed. */
+static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused)
+{
+ struct rcu_head *next, *list;
+ unsigned long flags;
+
+ /* Move the ready-to-invoke callbacks to a local list. */
+ local_irq_save(flags);
+ if (rcu_ctrlblk.donetail == &rcu_ctrlblk.rcucblist) {
+ /* No callbacks ready, so just leave. */
+ local_irq_restore(flags);
+ return;
+ }
+ list = rcu_ctrlblk.rcucblist;
+ rcu_ctrlblk.rcucblist = *rcu_ctrlblk.donetail;
+ *rcu_ctrlblk.donetail = NULL;
+ if (rcu_ctrlblk.curtail == rcu_ctrlblk.donetail)
+ rcu_ctrlblk.curtail = &rcu_ctrlblk.rcucblist;
+ rcu_ctrlblk.donetail = &rcu_ctrlblk.rcucblist;
+ local_irq_restore(flags);
+
+ /* Invoke the callbacks on the local list. */
+ while (list) {
+ next = list->next;
+ prefetch(next);
+ debug_rcu_head_unqueue(list);
+ local_bh_disable();
+ rcu_reclaim_tiny(list);
+ local_bh_enable();
+ list = next;
+ }
+}
+
+/*
+ * Wait for a grace period to elapse. But it is illegal to invoke
+ * synchronize_rcu() from within an RCU read-side critical section.
+ * Therefore, any legal call to synchronize_rcu() is a quiescent state,
+ * and so on a UP system, synchronize_rcu() need do nothing, other than
+ * let the polled APIs know that another grace period elapsed.
+ *
+ * (But Lai Jiangshan points out the benefits of doing might_sleep()
+ * to reduce latency.)
+ *
+ * Cool, huh? (Due to Josh Triplett.)
+ */
+void synchronize_rcu(void)
+{
+ RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) ||
+ lock_is_held(&rcu_lock_map) ||
+ lock_is_held(&rcu_sched_lock_map),
+ "Illegal synchronize_rcu() in RCU read-side critical section");
+ WRITE_ONCE(rcu_ctrlblk.gp_seq, rcu_ctrlblk.gp_seq + 2);
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu);
+
+static void tiny_rcu_leak_callback(struct rcu_head *rhp)
+{
+}
+
+/*
+ * Post an RCU callback to be invoked after the end of an RCU grace
+ * period. But since we have but one CPU, that would be after any
+ * quiescent state.
+ */
+void call_rcu(struct rcu_head *head, rcu_callback_t func)
+{
+ static atomic_t doublefrees;
+ unsigned long flags;
+
+ if (debug_rcu_head_queue(head)) {
+ if (atomic_inc_return(&doublefrees) < 4) {
+ pr_err("%s(): Double-freed CB %p->%pS()!!! ", __func__, head, head->func);
+ mem_dump_obj(head);
+ }
+
+ if (!__is_kvfree_rcu_offset((unsigned long)head->func))
+ WRITE_ONCE(head->func, tiny_rcu_leak_callback);
+ return;
+ }
+
+ head->func = func;
+ head->next = NULL;
+
+ local_irq_save(flags);
+ *rcu_ctrlblk.curtail = head;
+ rcu_ctrlblk.curtail = &head->next;
+ local_irq_restore(flags);
+
+ if (unlikely(is_idle_task(current))) {
+ /* force scheduling for rcu_qs() */
+ resched_cpu(0);
+ }
+}
+EXPORT_SYMBOL_GPL(call_rcu);
+
+/*
+ * Store a grace-period-counter "cookie". For more information,
+ * see the Tree RCU header comment.
+ */
+void get_completed_synchronize_rcu_full(struct rcu_gp_oldstate *rgosp)
+{
+ rgosp->rgos_norm = RCU_GET_STATE_COMPLETED;
+}
+EXPORT_SYMBOL_GPL(get_completed_synchronize_rcu_full);
+
+/*
+ * Return a grace-period-counter "cookie". For more information,
+ * see the Tree RCU header comment.
+ */
+unsigned long get_state_synchronize_rcu(void)
+{
+ return READ_ONCE(rcu_ctrlblk.gp_seq);
+}
+EXPORT_SYMBOL_GPL(get_state_synchronize_rcu);
+
+/*
+ * Return a grace-period-counter "cookie" and ensure that a future grace
+ * period completes. For more information, see the Tree RCU header comment.
+ */
+unsigned long start_poll_synchronize_rcu(void)
+{
+ unsigned long gp_seq = get_state_synchronize_rcu();
+
+ if (unlikely(is_idle_task(current))) {
+ /* force scheduling for rcu_qs() */
+ resched_cpu(0);
+ }
+ return gp_seq;
+}
+EXPORT_SYMBOL_GPL(start_poll_synchronize_rcu);
+
+/*
+ * Return true if the grace period corresponding to oldstate has completed
+ * and false otherwise. For more information, see the Tree RCU header
+ * comment.
+ */
+bool poll_state_synchronize_rcu(unsigned long oldstate)
+{
+ return oldstate == RCU_GET_STATE_COMPLETED || READ_ONCE(rcu_ctrlblk.gp_seq) != oldstate;
+}
+EXPORT_SYMBOL_GPL(poll_state_synchronize_rcu);
+
+#ifdef CONFIG_KASAN_GENERIC
+void kvfree_call_rcu(struct rcu_head *head, void *ptr)
+{
+ if (head)
+ kasan_record_aux_stack_noalloc(ptr);
+
+ __kvfree_call_rcu(head, ptr);
+}
+EXPORT_SYMBOL_GPL(kvfree_call_rcu);
+#endif
+
+void __init rcu_init(void)
+{
+ open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
+ rcu_early_boot_tests();
+}