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(). ... --- kernel/trace/rethook.c | 328 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 328 insertions(+) create mode 100644 kernel/trace/rethook.c (limited to 'kernel/trace/rethook.c') diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c new file mode 100644 index 000000000..32c3dfdb4 --- /dev/null +++ b/kernel/trace/rethook.c @@ -0,0 +1,328 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define pr_fmt(fmt) "rethook: " fmt + +#include +#include +#include +#include +#include +#include +#include + +/* Return hook list (shadow stack by list) */ + +/* + * This function is called from delayed_put_task_struct() when a task is + * dead and cleaned up to recycle any kretprobe instances associated with + * this task. These left over instances represent probed functions that + * have been called but will never return. + */ +void rethook_flush_task(struct task_struct *tk) +{ + struct rethook_node *rhn; + struct llist_node *node; + + node = __llist_del_all(&tk->rethooks); + while (node) { + rhn = container_of(node, struct rethook_node, llist); + node = node->next; + preempt_disable(); + rethook_recycle(rhn); + preempt_enable(); + } +} + +static void rethook_free_rcu(struct rcu_head *head) +{ + struct rethook *rh = container_of(head, struct rethook, rcu); + struct rethook_node *rhn; + struct freelist_node *node; + int count = 1; + + node = rh->pool.head; + while (node) { + rhn = container_of(node, struct rethook_node, freelist); + node = node->next; + kfree(rhn); + count++; + } + + /* The rh->ref is the number of pooled node + 1 */ + if (refcount_sub_and_test(count, &rh->ref)) + kfree(rh); +} + +/** + * rethook_free() - Free struct rethook. + * @rh: the struct rethook to be freed. + * + * Free the rethook. Before calling this function, user must ensure the + * @rh::data is cleaned if needed (or, the handler can access it after + * calling this function.) This function will set the @rh to be freed + * after all rethook_node are freed (not soon). And the caller must + * not touch @rh after calling this. + */ +void rethook_free(struct rethook *rh) +{ + WRITE_ONCE(rh->handler, NULL); + + call_rcu(&rh->rcu, rethook_free_rcu); +} + +/** + * rethook_alloc() - Allocate struct rethook. + * @data: a data to pass the @handler when hooking the return. + * @handler: the return hook callback function. + * + * Allocate and initialize a new rethook with @data and @handler. + * Return NULL if memory allocation fails or @handler is NULL. + * Note that @handler == NULL means this rethook is going to be freed. + */ +struct rethook *rethook_alloc(void *data, rethook_handler_t handler) +{ + struct rethook *rh = kzalloc(sizeof(struct rethook), GFP_KERNEL); + + if (!rh || !handler) { + kfree(rh); + return NULL; + } + + rh->data = data; + rh->handler = handler; + rh->pool.head = NULL; + refcount_set(&rh->ref, 1); + + return rh; +} + +/** + * rethook_add_node() - Add a new node to the rethook. + * @rh: the struct rethook. + * @node: the struct rethook_node to be added. + * + * Add @node to @rh. User must allocate @node (as a part of user's + * data structure.) The @node fields are initialized in this function. + */ +void rethook_add_node(struct rethook *rh, struct rethook_node *node) +{ + node->rethook = rh; + freelist_add(&node->freelist, &rh->pool); + refcount_inc(&rh->ref); +} + +static void free_rethook_node_rcu(struct rcu_head *head) +{ + struct rethook_node *node = container_of(head, struct rethook_node, rcu); + + if (refcount_dec_and_test(&node->rethook->ref)) + kfree(node->rethook); + kfree(node); +} + +/** + * rethook_recycle() - return the node to rethook. + * @node: The struct rethook_node to be returned. + * + * Return back the @node to @node::rethook. If the @node::rethook is already + * marked as freed, this will free the @node. + */ +void rethook_recycle(struct rethook_node *node) +{ + lockdep_assert_preemption_disabled(); + + if (likely(READ_ONCE(node->rethook->handler))) + freelist_add(&node->freelist, &node->rethook->pool); + else + call_rcu(&node->rcu, free_rethook_node_rcu); +} +NOKPROBE_SYMBOL(rethook_recycle); + +/** + * rethook_try_get() - get an unused rethook node. + * @rh: The struct rethook which pools the nodes. + * + * Get an unused rethook node from @rh. If the node pool is empty, this + * will return NULL. Caller must disable preemption. + */ +struct rethook_node *rethook_try_get(struct rethook *rh) +{ + rethook_handler_t handler = READ_ONCE(rh->handler); + struct freelist_node *fn; + + lockdep_assert_preemption_disabled(); + + /* Check whether @rh is going to be freed. */ + if (unlikely(!handler)) + return NULL; + + /* + * This expects the caller will set up a rethook on a function entry. + * When the function returns, the rethook will eventually be reclaimed + * or released in the rethook_recycle() with call_rcu(). + * This means the caller must be run in the RCU-availabe context. + */ + if (unlikely(!rcu_is_watching())) + return NULL; + + fn = freelist_try_get(&rh->pool); + if (!fn) + return NULL; + + return container_of(fn, struct rethook_node, freelist); +} +NOKPROBE_SYMBOL(rethook_try_get); + +/** + * rethook_hook() - Hook the current function return. + * @node: The struct rethook node to hook the function return. + * @regs: The struct pt_regs for the function entry. + * @mcount: True if this is called from mcount(ftrace) context. + * + * Hook the current running function return. This must be called when the + * function entry (or at least @regs must be the registers of the function + * entry.) @mcount is used for identifying the context. If this is called + * from ftrace (mcount) callback, @mcount must be set true. If this is called + * from the real function entry (e.g. kprobes) @mcount must be set false. + * This is because the way to hook the function return depends on the context. + */ +void rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mcount) +{ + arch_rethook_prepare(node, regs, mcount); + __llist_add(&node->llist, ¤t->rethooks); +} +NOKPROBE_SYMBOL(rethook_hook); + +/* This assumes the 'tsk' is the current task or is not running. */ +static unsigned long __rethook_find_ret_addr(struct task_struct *tsk, + struct llist_node **cur) +{ + struct rethook_node *rh = NULL; + struct llist_node *node = *cur; + + if (!node) + node = tsk->rethooks.first; + else + node = node->next; + + while (node) { + rh = container_of(node, struct rethook_node, llist); + if (rh->ret_addr != (unsigned long)arch_rethook_trampoline) { + *cur = node; + return rh->ret_addr; + } + node = node->next; + } + return 0; +} +NOKPROBE_SYMBOL(__rethook_find_ret_addr); + +/** + * rethook_find_ret_addr -- Find correct return address modified by rethook + * @tsk: Target task + * @frame: A frame pointer + * @cur: a storage of the loop cursor llist_node pointer for next call + * + * Find the correct return address modified by a rethook on @tsk in unsigned + * long type. + * The @tsk must be 'current' or a task which is not running. @frame is a hint + * to get the currect return address - which is compared with the + * rethook::frame field. The @cur is a loop cursor for searching the + * kretprobe return addresses on the @tsk. The '*@cur' should be NULL at the + * first call, but '@cur' itself must NOT NULL. + * + * Returns found address value or zero if not found. + */ +unsigned long rethook_find_ret_addr(struct task_struct *tsk, unsigned long frame, + struct llist_node **cur) +{ + struct rethook_node *rhn = NULL; + unsigned long ret; + + if (WARN_ON_ONCE(!cur)) + return 0; + + if (WARN_ON_ONCE(tsk != current && task_is_running(tsk))) + return 0; + + do { + ret = __rethook_find_ret_addr(tsk, cur); + if (!ret) + break; + rhn = container_of(*cur, struct rethook_node, llist); + } while (rhn->frame != frame); + + return ret; +} +NOKPROBE_SYMBOL(rethook_find_ret_addr); + +void __weak arch_rethook_fixup_return(struct pt_regs *regs, + unsigned long correct_ret_addr) +{ + /* + * Do nothing by default. If the architecture which uses a + * frame pointer to record real return address on the stack, + * it should fill this function to fixup the return address + * so that stacktrace works from the rethook handler. + */ +} + +/* This function will be called from each arch-defined trampoline. */ +unsigned long rethook_trampoline_handler(struct pt_regs *regs, + unsigned long frame) +{ + struct llist_node *first, *node = NULL; + unsigned long correct_ret_addr; + rethook_handler_t handler; + struct rethook_node *rhn; + + correct_ret_addr = __rethook_find_ret_addr(current, &node); + if (!correct_ret_addr) { + pr_err("rethook: Return address not found! Maybe there is a bug in the kernel\n"); + BUG_ON(1); + } + + instruction_pointer_set(regs, correct_ret_addr); + + /* + * These loops must be protected from rethook_free_rcu() because those + * are accessing 'rhn->rethook'. + */ + preempt_disable(); + + /* + * Run the handler on the shadow stack. Do not unlink the list here because + * stackdump inside the handlers needs to decode it. + */ + first = current->rethooks.first; + while (first) { + rhn = container_of(first, struct rethook_node, llist); + if (WARN_ON_ONCE(rhn->frame != frame)) + break; + handler = READ_ONCE(rhn->rethook->handler); + if (handler) + handler(rhn, rhn->rethook->data, regs); + + if (first == node) + break; + first = first->next; + } + + /* Fixup registers for returning to correct address. */ + arch_rethook_fixup_return(regs, correct_ret_addr); + + /* Unlink used shadow stack */ + first = current->rethooks.first; + current->rethooks.first = node->next; + node->next = NULL; + + while (first) { + rhn = container_of(first, struct rethook_node, llist); + first = first->next; + rethook_recycle(rhn); + } + preempt_enable(); + + return correct_ret_addr; +} +NOKPROBE_SYMBOL(rethook_trampoline_handler); -- cgit v1.2.3