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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/trace/fprobe.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
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/trace/fprobe.c')
-rw-r--r--kernel/trace/fprobe.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
new file mode 100644
index 000000000..e8143e368
--- /dev/null
+++ b/kernel/trace/fprobe.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * fprobe - Simple ftrace probe wrapper for function entry.
+ */
+#define pr_fmt(fmt) "fprobe: " fmt
+
+#include <linux/err.h>
+#include <linux/fprobe.h>
+#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
+#include <linux/rethook.h>
+#include <linux/slab.h>
+#include <linux/sort.h>
+
+#include "trace.h"
+
+struct fprobe_rethook_node {
+ struct rethook_node node;
+ unsigned long entry_ip;
+};
+
+static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
+{
+ struct fprobe_rethook_node *fpr;
+ struct rethook_node *rh;
+ struct fprobe *fp;
+ int bit;
+
+ fp = container_of(ops, struct fprobe, ops);
+ if (fprobe_disabled(fp))
+ return;
+
+ bit = ftrace_test_recursion_trylock(ip, parent_ip);
+ if (bit < 0) {
+ fp->nmissed++;
+ return;
+ }
+
+ if (fp->entry_handler)
+ fp->entry_handler(fp, ip, ftrace_get_regs(fregs));
+
+ if (fp->exit_handler) {
+ rh = rethook_try_get(fp->rethook);
+ if (!rh) {
+ fp->nmissed++;
+ goto out;
+ }
+ fpr = container_of(rh, struct fprobe_rethook_node, node);
+ fpr->entry_ip = ip;
+ rethook_hook(rh, ftrace_get_regs(fregs), true);
+ }
+
+out:
+ ftrace_test_recursion_unlock(bit);
+}
+NOKPROBE_SYMBOL(fprobe_handler);
+
+static void fprobe_kprobe_handler(unsigned long ip, unsigned long parent_ip,
+ struct ftrace_ops *ops, struct ftrace_regs *fregs)
+{
+ struct fprobe *fp = container_of(ops, struct fprobe, ops);
+
+ if (unlikely(kprobe_running())) {
+ fp->nmissed++;
+ return;
+ }
+ kprobe_busy_begin();
+ fprobe_handler(ip, parent_ip, ops, fregs);
+ kprobe_busy_end();
+}
+
+static void fprobe_exit_handler(struct rethook_node *rh, void *data,
+ struct pt_regs *regs)
+{
+ struct fprobe *fp = (struct fprobe *)data;
+ struct fprobe_rethook_node *fpr;
+
+ if (!fp || fprobe_disabled(fp))
+ return;
+
+ fpr = container_of(rh, struct fprobe_rethook_node, node);
+
+ fp->exit_handler(fp, fpr->entry_ip, regs);
+}
+NOKPROBE_SYMBOL(fprobe_exit_handler);
+
+static int symbols_cmp(const void *a, const void *b)
+{
+ const char **str_a = (const char **) a;
+ const char **str_b = (const char **) b;
+
+ return strcmp(*str_a, *str_b);
+}
+
+/* Convert ftrace location address from symbols */
+static unsigned long *get_ftrace_locations(const char **syms, int num)
+{
+ unsigned long *addrs;
+
+ /* Convert symbols to symbol address */
+ addrs = kcalloc(num, sizeof(*addrs), GFP_KERNEL);
+ if (!addrs)
+ return ERR_PTR(-ENOMEM);
+
+ /* ftrace_lookup_symbols expects sorted symbols */
+ sort(syms, num, sizeof(*syms), symbols_cmp, NULL);
+
+ if (!ftrace_lookup_symbols(syms, num, addrs))
+ return addrs;
+
+ kfree(addrs);
+ return ERR_PTR(-ENOENT);
+}
+
+static void fprobe_init(struct fprobe *fp)
+{
+ fp->nmissed = 0;
+ if (fprobe_shared_with_kprobes(fp))
+ fp->ops.func = fprobe_kprobe_handler;
+ else
+ fp->ops.func = fprobe_handler;
+ fp->ops.flags |= FTRACE_OPS_FL_SAVE_REGS;
+}
+
+static int fprobe_init_rethook(struct fprobe *fp, int num)
+{
+ int i, size;
+
+ if (num < 0)
+ return -EINVAL;
+
+ if (!fp->exit_handler) {
+ fp->rethook = NULL;
+ return 0;
+ }
+
+ /* Initialize rethook if needed */
+ size = num * num_possible_cpus() * 2;
+ if (size < 0)
+ return -E2BIG;
+
+ fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler);
+ if (!fp->rethook)
+ return -ENOMEM;
+ for (i = 0; i < size; i++) {
+ struct fprobe_rethook_node *node;
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node) {
+ rethook_free(fp->rethook);
+ fp->rethook = NULL;
+ return -ENOMEM;
+ }
+ rethook_add_node(fp->rethook, &node->node);
+ }
+ return 0;
+}
+
+static void fprobe_fail_cleanup(struct fprobe *fp)
+{
+ if (fp->rethook) {
+ /* Don't need to cleanup rethook->handler because this is not used. */
+ rethook_free(fp->rethook);
+ fp->rethook = NULL;
+ }
+ ftrace_free_filter(&fp->ops);
+}
+
+/**
+ * register_fprobe() - Register fprobe to ftrace by pattern.
+ * @fp: A fprobe data structure to be registered.
+ * @filter: A wildcard pattern of probed symbols.
+ * @notfilter: A wildcard pattern of NOT probed symbols.
+ *
+ * Register @fp to ftrace for enabling the probe on the symbols matched to @filter.
+ * If @notfilter is not NULL, the symbols matched the @notfilter are not probed.
+ *
+ * Return 0 if @fp is registered successfully, -errno if not.
+ */
+int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter)
+{
+ struct ftrace_hash *hash;
+ unsigned char *str;
+ int ret, len;
+
+ if (!fp || !filter)
+ return -EINVAL;
+
+ fprobe_init(fp);
+
+ len = strlen(filter);
+ str = kstrdup(filter, GFP_KERNEL);
+ ret = ftrace_set_filter(&fp->ops, str, len, 0);
+ kfree(str);
+ if (ret)
+ return ret;
+
+ if (notfilter) {
+ len = strlen(notfilter);
+ str = kstrdup(notfilter, GFP_KERNEL);
+ ret = ftrace_set_notrace(&fp->ops, str, len, 0);
+ kfree(str);
+ if (ret)
+ goto out;
+ }
+
+ /* TODO:
+ * correctly calculate the total number of filtered symbols
+ * from both filter and notfilter.
+ */
+ hash = rcu_access_pointer(fp->ops.local_hash.filter_hash);
+ if (WARN_ON_ONCE(!hash))
+ goto out;
+
+ ret = fprobe_init_rethook(fp, (int)hash->count);
+ if (!ret)
+ ret = register_ftrace_function(&fp->ops);
+
+out:
+ if (ret)
+ fprobe_fail_cleanup(fp);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_fprobe);
+
+/**
+ * register_fprobe_ips() - Register fprobe to ftrace by address.
+ * @fp: A fprobe data structure to be registered.
+ * @addrs: An array of target ftrace location addresses.
+ * @num: The number of entries of @addrs.
+ *
+ * Register @fp to ftrace for enabling the probe on the address given by @addrs.
+ * The @addrs must be the addresses of ftrace location address, which may be
+ * the symbol address + arch-dependent offset.
+ * If you unsure what this mean, please use other registration functions.
+ *
+ * Return 0 if @fp is registered successfully, -errno if not.
+ */
+int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num)
+{
+ int ret;
+
+ if (!fp || !addrs || num <= 0)
+ return -EINVAL;
+
+ fprobe_init(fp);
+
+ ret = ftrace_set_filter_ips(&fp->ops, addrs, num, 0, 0);
+ if (ret)
+ return ret;
+
+ ret = fprobe_init_rethook(fp, num);
+ if (!ret)
+ ret = register_ftrace_function(&fp->ops);
+
+ if (ret)
+ fprobe_fail_cleanup(fp);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_fprobe_ips);
+
+/**
+ * register_fprobe_syms() - Register fprobe to ftrace by symbols.
+ * @fp: A fprobe data structure to be registered.
+ * @syms: An array of target symbols.
+ * @num: The number of entries of @syms.
+ *
+ * Register @fp to the symbols given by @syms array. This will be useful if
+ * you are sure the symbols exist in the kernel.
+ *
+ * Return 0 if @fp is registered successfully, -errno if not.
+ */
+int register_fprobe_syms(struct fprobe *fp, const char **syms, int num)
+{
+ unsigned long *addrs;
+ int ret;
+
+ if (!fp || !syms || num <= 0)
+ return -EINVAL;
+
+ addrs = get_ftrace_locations(syms, num);
+ if (IS_ERR(addrs))
+ return PTR_ERR(addrs);
+
+ ret = register_fprobe_ips(fp, addrs, num);
+
+ kfree(addrs);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_fprobe_syms);
+
+/**
+ * unregister_fprobe() - Unregister fprobe from ftrace
+ * @fp: A fprobe data structure to be unregistered.
+ *
+ * Unregister fprobe (and remove ftrace hooks from the function entries).
+ *
+ * Return 0 if @fp is unregistered successfully, -errno if not.
+ */
+int unregister_fprobe(struct fprobe *fp)
+{
+ int ret;
+
+ if (!fp || (fp->ops.saved_func != fprobe_handler &&
+ fp->ops.saved_func != fprobe_kprobe_handler))
+ return -EINVAL;
+
+ /*
+ * rethook_free() starts disabling the rethook, but the rethook handlers
+ * may be running on other processors at this point. To make sure that all
+ * current running handlers are finished, call unregister_ftrace_function()
+ * after this.
+ */
+ if (fp->rethook)
+ rethook_free(fp->rethook);
+
+ ret = unregister_ftrace_function(&fp->ops);
+ if (ret < 0)
+ return ret;
+
+ ftrace_free_filter(&fp->ops);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(unregister_fprobe);