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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 /arch/powerpc/kernel/optprobes.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 'arch/powerpc/kernel/optprobes.c')
-rw-r--r--arch/powerpc/kernel/optprobes.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/optprobes.c b/arch/powerpc/kernel/optprobes.c
new file mode 100644
index 000000000..004fae204
--- /dev/null
+++ b/arch/powerpc/kernel/optprobes.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Code for Kernel probes Jump optimization.
+ *
+ * Copyright 2017, Anju T, IBM Corp.
+ */
+
+#include <linux/kprobes.h>
+#include <linux/jump_label.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <asm/kprobes.h>
+#include <asm/ptrace.h>
+#include <asm/cacheflush.h>
+#include <asm/code-patching.h>
+#include <asm/sstep.h>
+#include <asm/ppc-opcode.h>
+#include <asm/inst.h>
+
+#define TMPL_CALL_HDLR_IDX (optprobe_template_call_handler - optprobe_template_entry)
+#define TMPL_EMULATE_IDX (optprobe_template_call_emulate - optprobe_template_entry)
+#define TMPL_RET_IDX (optprobe_template_ret - optprobe_template_entry)
+#define TMPL_OP_IDX (optprobe_template_op_address - optprobe_template_entry)
+#define TMPL_INSN_IDX (optprobe_template_insn - optprobe_template_entry)
+#define TMPL_END_IDX (optprobe_template_end - optprobe_template_entry)
+
+static bool insn_page_in_use;
+
+void *alloc_optinsn_page(void)
+{
+ if (insn_page_in_use)
+ return NULL;
+ insn_page_in_use = true;
+ return &optinsn_slot;
+}
+
+void free_optinsn_page(void *page)
+{
+ insn_page_in_use = false;
+}
+
+/*
+ * Check if we can optimize this probe. Returns NIP post-emulation if this can
+ * be optimized and 0 otherwise.
+ */
+static unsigned long can_optimize(struct kprobe *p)
+{
+ struct pt_regs regs;
+ struct instruction_op op;
+ unsigned long nip = 0;
+ unsigned long addr = (unsigned long)p->addr;
+
+ /*
+ * kprobe placed for kretprobe during boot time
+ * has a 'nop' instruction, which can be emulated.
+ * So further checks can be skipped.
+ */
+ if (p->addr == (kprobe_opcode_t *)&__kretprobe_trampoline)
+ return addr + sizeof(kprobe_opcode_t);
+
+ /*
+ * We only support optimizing kernel addresses, but not
+ * module addresses.
+ *
+ * FIXME: Optimize kprobes placed in module addresses.
+ */
+ if (!is_kernel_addr(addr))
+ return 0;
+
+ memset(&regs, 0, sizeof(struct pt_regs));
+ regs.nip = addr;
+ regs.trap = 0x0;
+ regs.msr = MSR_KERNEL;
+
+ /*
+ * Kprobe placed in conditional branch instructions are
+ * not optimized, as we can't predict the nip prior with
+ * dummy pt_regs and can not ensure that the return branch
+ * from detour buffer falls in the range of address (i.e 32MB).
+ * A branch back from trampoline is set up in the detour buffer
+ * to the nip returned by the analyse_instr() here.
+ *
+ * Ensure that the instruction is not a conditional branch,
+ * and that can be emulated.
+ */
+ if (!is_conditional_branch(ppc_inst_read(p->ainsn.insn)) &&
+ analyse_instr(&op, &regs, ppc_inst_read(p->ainsn.insn)) == 1) {
+ emulate_update_regs(&regs, &op);
+ nip = regs.nip;
+ }
+
+ return nip;
+}
+
+static void optimized_callback(struct optimized_kprobe *op,
+ struct pt_regs *regs)
+{
+ /* This is possible if op is under delayed unoptimizing */
+ if (kprobe_disabled(&op->kp))
+ return;
+
+ preempt_disable();
+
+ if (kprobe_running()) {
+ kprobes_inc_nmissed_count(&op->kp);
+ } else {
+ __this_cpu_write(current_kprobe, &op->kp);
+ regs_set_return_ip(regs, (unsigned long)op->kp.addr);
+ get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
+ opt_pre_handler(&op->kp, regs);
+ __this_cpu_write(current_kprobe, NULL);
+ }
+
+ preempt_enable();
+}
+NOKPROBE_SYMBOL(optimized_callback);
+
+void arch_remove_optimized_kprobe(struct optimized_kprobe *op)
+{
+ if (op->optinsn.insn) {
+ free_optinsn_slot(op->optinsn.insn, 1);
+ op->optinsn.insn = NULL;
+ }
+}
+
+static void patch_imm32_load_insns(unsigned long val, int reg, kprobe_opcode_t *addr)
+{
+ patch_instruction(addr++, ppc_inst(PPC_RAW_LIS(reg, PPC_HI(val))));
+ patch_instruction(addr, ppc_inst(PPC_RAW_ORI(reg, reg, PPC_LO(val))));
+}
+
+/*
+ * Generate instructions to load provided immediate 64-bit value
+ * to register 'reg' and patch these instructions at 'addr'.
+ */
+static void patch_imm64_load_insns(unsigned long long val, int reg, kprobe_opcode_t *addr)
+{
+ patch_instruction(addr++, ppc_inst(PPC_RAW_LIS(reg, PPC_HIGHEST(val))));
+ patch_instruction(addr++, ppc_inst(PPC_RAW_ORI(reg, reg, PPC_HIGHER(val))));
+ patch_instruction(addr++, ppc_inst(PPC_RAW_SLDI(reg, reg, 32)));
+ patch_instruction(addr++, ppc_inst(PPC_RAW_ORIS(reg, reg, PPC_HI(val))));
+ patch_instruction(addr, ppc_inst(PPC_RAW_ORI(reg, reg, PPC_LO(val))));
+}
+
+static void patch_imm_load_insns(unsigned long val, int reg, kprobe_opcode_t *addr)
+{
+ if (IS_ENABLED(CONFIG_PPC64))
+ patch_imm64_load_insns(val, reg, addr);
+ else
+ patch_imm32_load_insns(val, reg, addr);
+}
+
+int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *p)
+{
+ ppc_inst_t branch_op_callback, branch_emulate_step, temp;
+ unsigned long op_callback_addr, emulate_step_addr;
+ kprobe_opcode_t *buff;
+ long b_offset;
+ unsigned long nip, size;
+ int rc, i;
+
+ nip = can_optimize(p);
+ if (!nip)
+ return -EILSEQ;
+
+ /* Allocate instruction slot for detour buffer */
+ buff = get_optinsn_slot();
+ if (!buff)
+ return -ENOMEM;
+
+ /*
+ * OPTPROBE uses 'b' instruction to branch to optinsn.insn.
+ *
+ * The target address has to be relatively nearby, to permit use
+ * of branch instruction in powerpc, because the address is specified
+ * in an immediate field in the instruction opcode itself, ie 24 bits
+ * in the opcode specify the address. Therefore the address should
+ * be within 32MB on either side of the current instruction.
+ */
+ b_offset = (unsigned long)buff - (unsigned long)p->addr;
+ if (!is_offset_in_branch_range(b_offset))
+ goto error;
+
+ /* Check if the return address is also within 32MB range */
+ b_offset = (unsigned long)(buff + TMPL_RET_IDX) - nip;
+ if (!is_offset_in_branch_range(b_offset))
+ goto error;
+
+ /* Setup template */
+ /* We can optimize this via patch_instruction_window later */
+ size = (TMPL_END_IDX * sizeof(kprobe_opcode_t)) / sizeof(int);
+ pr_devel("Copying template to %p, size %lu\n", buff, size);
+ for (i = 0; i < size; i++) {
+ rc = patch_instruction(buff + i, ppc_inst(*(optprobe_template_entry + i)));
+ if (rc < 0)
+ goto error;
+ }
+
+ /*
+ * Fixup the template with instructions to:
+ * 1. load the address of the actual probepoint
+ */
+ patch_imm_load_insns((unsigned long)op, 3, buff + TMPL_OP_IDX);
+
+ /*
+ * 2. branch to optimized_callback() and emulate_step()
+ */
+ op_callback_addr = ppc_kallsyms_lookup_name("optimized_callback");
+ emulate_step_addr = ppc_kallsyms_lookup_name("emulate_step");
+ if (!op_callback_addr || !emulate_step_addr) {
+ WARN(1, "Unable to lookup optimized_callback()/emulate_step()\n");
+ goto error;
+ }
+
+ rc = create_branch(&branch_op_callback, buff + TMPL_CALL_HDLR_IDX,
+ op_callback_addr, BRANCH_SET_LINK);
+
+ rc |= create_branch(&branch_emulate_step, buff + TMPL_EMULATE_IDX,
+ emulate_step_addr, BRANCH_SET_LINK);
+
+ if (rc)
+ goto error;
+
+ patch_instruction(buff + TMPL_CALL_HDLR_IDX, branch_op_callback);
+ patch_instruction(buff + TMPL_EMULATE_IDX, branch_emulate_step);
+
+ /*
+ * 3. load instruction to be emulated into relevant register, and
+ */
+ temp = ppc_inst_read(p->ainsn.insn);
+ patch_imm_load_insns(ppc_inst_as_ulong(temp), 4, buff + TMPL_INSN_IDX);
+
+ /*
+ * 4. branch back from trampoline
+ */
+ patch_branch(buff + TMPL_RET_IDX, nip, 0);
+
+ flush_icache_range((unsigned long)buff, (unsigned long)(&buff[TMPL_END_IDX]));
+
+ op->optinsn.insn = buff;
+
+ return 0;
+
+error:
+ free_optinsn_slot(buff, 0);
+ return -ERANGE;
+
+}
+
+int arch_prepared_optinsn(struct arch_optimized_insn *optinsn)
+{
+ return optinsn->insn != NULL;
+}
+
+/*
+ * On powerpc, Optprobes always replaces one instruction (4 bytes
+ * aligned and 4 bytes long). It is impossible to encounter another
+ * kprobe in this address range. So always return 0.
+ */
+int arch_check_optimized_kprobe(struct optimized_kprobe *op)
+{
+ return 0;
+}
+
+void arch_optimize_kprobes(struct list_head *oplist)
+{
+ ppc_inst_t instr;
+ struct optimized_kprobe *op;
+ struct optimized_kprobe *tmp;
+
+ list_for_each_entry_safe(op, tmp, oplist, list) {
+ /*
+ * Backup instructions which will be replaced
+ * by jump address
+ */
+ memcpy(op->optinsn.copied_insn, op->kp.addr, RELATIVEJUMP_SIZE);
+ create_branch(&instr, op->kp.addr, (unsigned long)op->optinsn.insn, 0);
+ patch_instruction(op->kp.addr, instr);
+ list_del_init(&op->list);
+ }
+}
+
+void arch_unoptimize_kprobe(struct optimized_kprobe *op)
+{
+ arch_arm_kprobe(&op->kp);
+}
+
+void arch_unoptimize_kprobes(struct list_head *oplist, struct list_head *done_list)
+{
+ struct optimized_kprobe *op;
+ struct optimized_kprobe *tmp;
+
+ list_for_each_entry_safe(op, tmp, oplist, list) {
+ arch_unoptimize_kprobe(op);
+ list_move(&op->list, done_list);
+ }
+}
+
+int arch_within_optimized_kprobe(struct optimized_kprobe *op, kprobe_opcode_t *addr)
+{
+ return (op->kp.addr <= addr &&
+ op->kp.addr + (RELATIVEJUMP_SIZE / sizeof(kprobe_opcode_t)) > addr);
+}