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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/arm64/kernel/probes
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 'arch/arm64/kernel/probes')
-rw-r--r--arch/arm64/kernel/probes/Makefile6
-rw-r--r--arch/arm64/kernel/probes/decode-insn.c168
-rw-r--r--arch/arm64/kernel/probes/decode-insn.h33
-rw-r--r--arch/arm64/kernel/probes/kprobes.c425
-rw-r--r--arch/arm64/kernel/probes/kprobes_trampoline.S86
-rw-r--r--arch/arm64/kernel/probes/simulate-insn.c202
-rw-r--r--arch/arm64/kernel/probes/simulate-insn.h20
-rw-r--r--arch/arm64/kernel/probes/uprobes.c208
8 files changed, 1148 insertions, 0 deletions
diff --git a/arch/arm64/kernel/probes/Makefile b/arch/arm64/kernel/probes/Makefile
new file mode 100644
index 000000000..8e4be92e2
--- /dev/null
+++ b/arch/arm64/kernel/probes/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o \
+ kprobes_trampoline.o \
+ simulate-insn.o
+obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o \
+ simulate-insn.o
diff --git a/arch/arm64/kernel/probes/decode-insn.c b/arch/arm64/kernel/probes/decode-insn.c
new file mode 100644
index 000000000..968d5fffe
--- /dev/null
+++ b/arch/arm64/kernel/probes/decode-insn.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/arm64/kernel/probes/decode-insn.c
+ *
+ * Copyright (C) 2013 Linaro Limited.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <asm/insn.h>
+#include <asm/sections.h>
+
+#include "decode-insn.h"
+#include "simulate-insn.h"
+
+static bool __kprobes aarch64_insn_is_steppable(u32 insn)
+{
+ /*
+ * Branch instructions will write a new value into the PC which is
+ * likely to be relative to the XOL address and therefore invalid.
+ * Deliberate generation of an exception during stepping is also not
+ * currently safe. Lastly, MSR instructions can do any number of nasty
+ * things we can't handle during single-stepping.
+ */
+ if (aarch64_insn_is_class_branch_sys(insn)) {
+ if (aarch64_insn_is_branch(insn) ||
+ aarch64_insn_is_msr_imm(insn) ||
+ aarch64_insn_is_msr_reg(insn) ||
+ aarch64_insn_is_exception(insn) ||
+ aarch64_insn_is_eret(insn) ||
+ aarch64_insn_is_eret_auth(insn))
+ return false;
+
+ /*
+ * The MRS instruction may not return a correct value when
+ * executing in the single-stepping environment. We do make one
+ * exception, for reading the DAIF bits.
+ */
+ if (aarch64_insn_is_mrs(insn))
+ return aarch64_insn_extract_system_reg(insn)
+ != AARCH64_INSN_SPCLREG_DAIF;
+
+ /*
+ * The HINT instruction is steppable only if it is in whitelist
+ * and the rest of other such instructions are blocked for
+ * single stepping as they may cause exception or other
+ * unintended behaviour.
+ */
+ if (aarch64_insn_is_hint(insn))
+ return aarch64_insn_is_steppable_hint(insn);
+
+ return true;
+ }
+
+ /*
+ * Instructions which load PC relative literals are not going to work
+ * when executed from an XOL slot. Instructions doing an exclusive
+ * load/store are not going to complete successfully when single-step
+ * exception handling happens in the middle of the sequence.
+ */
+ if (aarch64_insn_uses_literal(insn) ||
+ aarch64_insn_is_exclusive(insn))
+ return false;
+
+ return true;
+}
+
+/* Return:
+ * INSN_REJECTED If instruction is one not allowed to kprobe,
+ * INSN_GOOD If instruction is supported and uses instruction slot,
+ * INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
+ */
+enum probe_insn __kprobes
+arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *api)
+{
+ /*
+ * Instructions reading or modifying the PC won't work from the XOL
+ * slot.
+ */
+ if (aarch64_insn_is_steppable(insn))
+ return INSN_GOOD;
+
+ if (aarch64_insn_is_bcond(insn)) {
+ api->handler = simulate_b_cond;
+ } else if (aarch64_insn_is_cbz(insn) ||
+ aarch64_insn_is_cbnz(insn)) {
+ api->handler = simulate_cbz_cbnz;
+ } else if (aarch64_insn_is_tbz(insn) ||
+ aarch64_insn_is_tbnz(insn)) {
+ api->handler = simulate_tbz_tbnz;
+ } else if (aarch64_insn_is_adr_adrp(insn)) {
+ api->handler = simulate_adr_adrp;
+ } else if (aarch64_insn_is_b(insn) ||
+ aarch64_insn_is_bl(insn)) {
+ api->handler = simulate_b_bl;
+ } else if (aarch64_insn_is_br(insn) ||
+ aarch64_insn_is_blr(insn) ||
+ aarch64_insn_is_ret(insn)) {
+ api->handler = simulate_br_blr_ret;
+ } else if (aarch64_insn_is_ldr_lit(insn)) {
+ api->handler = simulate_ldr_literal;
+ } else if (aarch64_insn_is_ldrsw_lit(insn)) {
+ api->handler = simulate_ldrsw_literal;
+ } else {
+ /*
+ * Instruction cannot be stepped out-of-line and we don't
+ * (yet) simulate it.
+ */
+ return INSN_REJECTED;
+ }
+
+ return INSN_GOOD_NO_SLOT;
+}
+
+#ifdef CONFIG_KPROBES
+static bool __kprobes
+is_probed_address_atomic(kprobe_opcode_t *scan_start, kprobe_opcode_t *scan_end)
+{
+ while (scan_start >= scan_end) {
+ /*
+ * atomic region starts from exclusive load and ends with
+ * exclusive store.
+ */
+ if (aarch64_insn_is_store_ex(le32_to_cpu(*scan_start)))
+ return false;
+ else if (aarch64_insn_is_load_ex(le32_to_cpu(*scan_start)))
+ return true;
+ scan_start--;
+ }
+
+ return false;
+}
+
+enum probe_insn __kprobes
+arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi)
+{
+ enum probe_insn decoded;
+ probe_opcode_t insn = le32_to_cpu(*addr);
+ probe_opcode_t *scan_end = NULL;
+ unsigned long size = 0, offset = 0;
+
+ /*
+ * If there's a symbol defined in front of and near enough to
+ * the probe address assume it is the entry point to this
+ * code and use it to further limit how far back we search
+ * when determining if we're in an atomic sequence. If we could
+ * not find any symbol skip the atomic test altogether as we
+ * could otherwise end up searching irrelevant text/literals.
+ * KPROBES depends on KALLSYMS so this last case should never
+ * happen.
+ */
+ if (kallsyms_lookup_size_offset((unsigned long) addr, &size, &offset)) {
+ if (offset < (MAX_ATOMIC_CONTEXT_SIZE*sizeof(kprobe_opcode_t)))
+ scan_end = addr - (offset / sizeof(kprobe_opcode_t));
+ else
+ scan_end = addr - MAX_ATOMIC_CONTEXT_SIZE;
+ }
+ decoded = arm_probe_decode_insn(insn, &asi->api);
+
+ if (decoded != INSN_REJECTED && scan_end)
+ if (is_probed_address_atomic(addr - 1, scan_end))
+ return INSN_REJECTED;
+
+ return decoded;
+}
+#endif
diff --git a/arch/arm64/kernel/probes/decode-insn.h b/arch/arm64/kernel/probes/decode-insn.h
new file mode 100644
index 000000000..8b758c5a2
--- /dev/null
+++ b/arch/arm64/kernel/probes/decode-insn.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * arch/arm64/kernel/probes/decode-insn.h
+ *
+ * Copyright (C) 2013 Linaro Limited.
+ */
+
+#ifndef _ARM_KERNEL_KPROBES_ARM64_H
+#define _ARM_KERNEL_KPROBES_ARM64_H
+
+#include <asm/kprobes.h>
+
+/*
+ * ARM strongly recommends a limit of 128 bytes between LoadExcl and
+ * StoreExcl instructions in a single thread of execution. So keep the
+ * max atomic context size as 32.
+ */
+#define MAX_ATOMIC_CONTEXT_SIZE (128 / sizeof(kprobe_opcode_t))
+
+enum probe_insn {
+ INSN_REJECTED,
+ INSN_GOOD_NO_SLOT,
+ INSN_GOOD,
+};
+
+#ifdef CONFIG_KPROBES
+enum probe_insn __kprobes
+arm_kprobe_decode_insn(kprobe_opcode_t *addr, struct arch_specific_insn *asi);
+#endif
+enum probe_insn __kprobes
+arm_probe_decode_insn(probe_opcode_t insn, struct arch_probe_insn *asi);
+
+#endif /* _ARM_KERNEL_KPROBES_ARM64_H */
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
new file mode 100644
index 000000000..70b91a8c6
--- /dev/null
+++ b/arch/arm64/kernel/probes/kprobes.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/arm64/kernel/probes/kprobes.c
+ *
+ * Kprobes support for ARM64
+ *
+ * Copyright (C) 2013 Linaro Limited.
+ * Author: Sandeepa Prabhu <sandeepa.prabhu@linaro.org>
+ */
+
+#define pr_fmt(fmt) "kprobes: " fmt
+
+#include <linux/extable.h>
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/sched/debug.h>
+#include <linux/set_memory.h>
+#include <linux/slab.h>
+#include <linux/stop_machine.h>
+#include <linux/stringify.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
+
+#include <asm/cacheflush.h>
+#include <asm/daifflags.h>
+#include <asm/debug-monitors.h>
+#include <asm/insn.h>
+#include <asm/irq.h>
+#include <asm/patching.h>
+#include <asm/ptrace.h>
+#include <asm/sections.h>
+#include <asm/system_misc.h>
+#include <asm/traps.h>
+
+#include "decode-insn.h"
+
+DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+
+static void __kprobes
+post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);
+
+static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
+{
+ kprobe_opcode_t *addr = p->ainsn.api.insn;
+
+ /*
+ * Prepare insn slot, Mark Rutland points out it depends on a coupe of
+ * subtleties:
+ *
+ * - That the I-cache maintenance for these instructions is complete
+ * *before* the kprobe BRK is written (and aarch64_insn_patch_text_nosync()
+ * ensures this, but just omits causing a Context-Synchronization-Event
+ * on all CPUS).
+ *
+ * - That the kprobe BRK results in an exception (and consequently a
+ * Context-Synchronoization-Event), which ensures that the CPU will
+ * fetch thesingle-step slot instructions *after* this, ensuring that
+ * the new instructions are used
+ *
+ * It supposes to place ISB after patching to guarantee I-cache maintenance
+ * is observed on all CPUS, however, single-step slot is installed in
+ * the BRK exception handler, so it is unnecessary to generate
+ * Contex-Synchronization-Event via ISB again.
+ */
+ aarch64_insn_patch_text_nosync(addr, p->opcode);
+ aarch64_insn_patch_text_nosync(addr + 1, BRK64_OPCODE_KPROBES_SS);
+
+ /*
+ * Needs restoring of return address after stepping xol.
+ */
+ p->ainsn.api.restore = (unsigned long) p->addr +
+ sizeof(kprobe_opcode_t);
+}
+
+static void __kprobes arch_prepare_simulate(struct kprobe *p)
+{
+ /* This instructions is not executed xol. No need to adjust the PC */
+ p->ainsn.api.restore = 0;
+}
+
+static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+ if (p->ainsn.api.handler)
+ p->ainsn.api.handler((u32)p->opcode, (long)p->addr, regs);
+
+ /* single step simulated, now go for post processing */
+ post_kprobe_handler(p, kcb, regs);
+}
+
+int __kprobes arch_prepare_kprobe(struct kprobe *p)
+{
+ unsigned long probe_addr = (unsigned long)p->addr;
+
+ if (probe_addr & 0x3)
+ return -EINVAL;
+
+ /* copy instruction */
+ p->opcode = le32_to_cpu(*p->addr);
+
+ if (search_exception_tables(probe_addr))
+ return -EINVAL;
+
+ /* decode instruction */
+ switch (arm_kprobe_decode_insn(p->addr, &p->ainsn)) {
+ case INSN_REJECTED: /* insn not supported */
+ return -EINVAL;
+
+ case INSN_GOOD_NO_SLOT: /* insn need simulation */
+ p->ainsn.api.insn = NULL;
+ break;
+
+ case INSN_GOOD: /* instruction uses slot */
+ p->ainsn.api.insn = get_insn_slot();
+ if (!p->ainsn.api.insn)
+ return -ENOMEM;
+ break;
+ }
+
+ /* prepare the instruction */
+ if (p->ainsn.api.insn)
+ arch_prepare_ss_slot(p);
+ else
+ arch_prepare_simulate(p);
+
+ return 0;
+}
+
+void *alloc_insn_page(void)
+{
+ return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END,
+ GFP_KERNEL, PAGE_KERNEL_ROX, VM_FLUSH_RESET_PERMS,
+ NUMA_NO_NODE, __builtin_return_address(0));
+}
+
+/* arm kprobe: install breakpoint in text */
+void __kprobes arch_arm_kprobe(struct kprobe *p)
+{
+ void *addr = p->addr;
+ u32 insn = BRK64_OPCODE_KPROBES;
+
+ aarch64_insn_patch_text(&addr, &insn, 1);
+}
+
+/* disarm kprobe: remove breakpoint from text */
+void __kprobes arch_disarm_kprobe(struct kprobe *p)
+{
+ void *addr = p->addr;
+
+ aarch64_insn_patch_text(&addr, &p->opcode, 1);
+}
+
+void __kprobes arch_remove_kprobe(struct kprobe *p)
+{
+ if (p->ainsn.api.insn) {
+ free_insn_slot(p->ainsn.api.insn, 0);
+ p->ainsn.api.insn = NULL;
+ }
+}
+
+static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+ kcb->prev_kprobe.kp = kprobe_running();
+ kcb->prev_kprobe.status = kcb->kprobe_status;
+}
+
+static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
+{
+ __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
+ kcb->kprobe_status = kcb->prev_kprobe.status;
+}
+
+static void __kprobes set_current_kprobe(struct kprobe *p)
+{
+ __this_cpu_write(current_kprobe, p);
+}
+
+/*
+ * Mask all of DAIF while executing the instruction out-of-line, to keep things
+ * simple and avoid nesting exceptions. Interrupts do have to be disabled since
+ * the kprobe state is per-CPU and doesn't get migrated.
+ */
+static void __kprobes kprobes_save_local_irqflag(struct kprobe_ctlblk *kcb,
+ struct pt_regs *regs)
+{
+ kcb->saved_irqflag = regs->pstate & DAIF_MASK;
+ regs->pstate |= DAIF_MASK;
+}
+
+static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb,
+ struct pt_regs *regs)
+{
+ regs->pstate &= ~DAIF_MASK;
+ regs->pstate |= kcb->saved_irqflag;
+}
+
+static void __kprobes setup_singlestep(struct kprobe *p,
+ struct pt_regs *regs,
+ struct kprobe_ctlblk *kcb, int reenter)
+{
+ unsigned long slot;
+
+ if (reenter) {
+ save_previous_kprobe(kcb);
+ set_current_kprobe(p);
+ kcb->kprobe_status = KPROBE_REENTER;
+ } else {
+ kcb->kprobe_status = KPROBE_HIT_SS;
+ }
+
+
+ if (p->ainsn.api.insn) {
+ /* prepare for single stepping */
+ slot = (unsigned long)p->ainsn.api.insn;
+
+ kprobes_save_local_irqflag(kcb, regs);
+ instruction_pointer_set(regs, slot);
+ } else {
+ /* insn simulation */
+ arch_simulate_insn(p, regs);
+ }
+}
+
+static int __kprobes reenter_kprobe(struct kprobe *p,
+ struct pt_regs *regs,
+ struct kprobe_ctlblk *kcb)
+{
+ switch (kcb->kprobe_status) {
+ case KPROBE_HIT_SSDONE:
+ case KPROBE_HIT_ACTIVE:
+ kprobes_inc_nmissed_count(p);
+ setup_singlestep(p, regs, kcb, 1);
+ break;
+ case KPROBE_HIT_SS:
+ case KPROBE_REENTER:
+ pr_warn("Failed to recover from reentered kprobes.\n");
+ dump_kprobe(p);
+ BUG();
+ break;
+ default:
+ WARN_ON(1);
+ return 0;
+ }
+
+ return 1;
+}
+
+static void __kprobes
+post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs)
+{
+ /* return addr restore if non-branching insn */
+ if (cur->ainsn.api.restore != 0)
+ instruction_pointer_set(regs, cur->ainsn.api.restore);
+
+ /* restore back original saved kprobe variables and continue */
+ if (kcb->kprobe_status == KPROBE_REENTER) {
+ restore_previous_kprobe(kcb);
+ return;
+ }
+ /* call post handler */
+ kcb->kprobe_status = KPROBE_HIT_SSDONE;
+ if (cur->post_handler)
+ cur->post_handler(cur, regs, 0);
+
+ reset_current_kprobe();
+}
+
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int fsr)
+{
+ struct kprobe *cur = kprobe_running();
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+ switch (kcb->kprobe_status) {
+ case KPROBE_HIT_SS:
+ case KPROBE_REENTER:
+ /*
+ * We are here because the instruction being single
+ * stepped caused a page fault. We reset the current
+ * kprobe and the ip points back to the probe address
+ * and allow the page fault handler to continue as a
+ * normal page fault.
+ */
+ instruction_pointer_set(regs, (unsigned long) cur->addr);
+ BUG_ON(!instruction_pointer(regs));
+
+ if (kcb->kprobe_status == KPROBE_REENTER) {
+ restore_previous_kprobe(kcb);
+ } else {
+ kprobes_restore_local_irqflag(kcb, regs);
+ reset_current_kprobe();
+ }
+
+ break;
+ }
+ return 0;
+}
+
+static int __kprobes
+kprobe_breakpoint_handler(struct pt_regs *regs, unsigned long esr)
+{
+ struct kprobe *p, *cur_kprobe;
+ struct kprobe_ctlblk *kcb;
+ unsigned long addr = instruction_pointer(regs);
+
+ kcb = get_kprobe_ctlblk();
+ cur_kprobe = kprobe_running();
+
+ p = get_kprobe((kprobe_opcode_t *) addr);
+ if (WARN_ON_ONCE(!p)) {
+ /*
+ * Something went wrong. This BRK used an immediate reserved
+ * for kprobes, but we couldn't find any corresponding probe.
+ */
+ return DBG_HOOK_ERROR;
+ }
+
+ if (cur_kprobe) {
+ /* Hit a kprobe inside another kprobe */
+ if (!reenter_kprobe(p, regs, kcb))
+ return DBG_HOOK_ERROR;
+ } else {
+ /* Probe hit */
+ set_current_kprobe(p);
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+ /*
+ * If we have no pre-handler or it returned 0, we
+ * continue with normal processing. If we have a
+ * pre-handler and it returned non-zero, it will
+ * modify the execution path and not need to single-step
+ * Let's just reset current kprobe and exit.
+ */
+ if (!p->pre_handler || !p->pre_handler(p, regs))
+ setup_singlestep(p, regs, kcb, 0);
+ else
+ reset_current_kprobe();
+ }
+
+ return DBG_HOOK_HANDLED;
+}
+
+static struct break_hook kprobes_break_hook = {
+ .imm = KPROBES_BRK_IMM,
+ .fn = kprobe_breakpoint_handler,
+};
+
+static int __kprobes
+kprobe_breakpoint_ss_handler(struct pt_regs *regs, unsigned long esr)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ unsigned long addr = instruction_pointer(regs);
+ struct kprobe *cur = kprobe_running();
+
+ if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) &&
+ ((unsigned long)&cur->ainsn.api.insn[1] == addr)) {
+ kprobes_restore_local_irqflag(kcb, regs);
+ post_kprobe_handler(cur, kcb, regs);
+
+ return DBG_HOOK_HANDLED;
+ }
+
+ /* not ours, kprobes should ignore it */
+ return DBG_HOOK_ERROR;
+}
+
+static struct break_hook kprobes_break_ss_hook = {
+ .imm = KPROBES_BRK_SS_IMM,
+ .fn = kprobe_breakpoint_ss_handler,
+};
+
+/*
+ * Provide a blacklist of symbols identifying ranges which cannot be kprobed.
+ * This blacklist is exposed to userspace via debugfs (kprobes/blacklist).
+ */
+int __init arch_populate_kprobe_blacklist(void)
+{
+ int ret;
+
+ ret = kprobe_add_area_blacklist((unsigned long)__entry_text_start,
+ (unsigned long)__entry_text_end);
+ if (ret)
+ return ret;
+ ret = kprobe_add_area_blacklist((unsigned long)__irqentry_text_start,
+ (unsigned long)__irqentry_text_end);
+ if (ret)
+ return ret;
+ ret = kprobe_add_area_blacklist((unsigned long)__hyp_text_start,
+ (unsigned long)__hyp_text_end);
+ if (ret || is_kernel_in_hyp_mode())
+ return ret;
+ ret = kprobe_add_area_blacklist((unsigned long)__hyp_idmap_text_start,
+ (unsigned long)__hyp_idmap_text_end);
+ return ret;
+}
+
+void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs)
+{
+ return (void *)kretprobe_trampoline_handler(regs, (void *)regs->regs[29]);
+}
+
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
+ struct pt_regs *regs)
+{
+ ri->ret_addr = (kprobe_opcode_t *)regs->regs[30];
+ ri->fp = (void *)regs->regs[29];
+
+ /* replace return addr (x30) with trampoline */
+ regs->regs[30] = (long)&__kretprobe_trampoline;
+}
+
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+{
+ return 0;
+}
+
+int __init arch_init_kprobes(void)
+{
+ register_kernel_break_hook(&kprobes_break_hook);
+ register_kernel_break_hook(&kprobes_break_ss_hook);
+
+ return 0;
+}
diff --git a/arch/arm64/kernel/probes/kprobes_trampoline.S b/arch/arm64/kernel/probes/kprobes_trampoline.S
new file mode 100644
index 000000000..9a6499bed
--- /dev/null
+++ b/arch/arm64/kernel/probes/kprobes_trampoline.S
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * trampoline entry and return code for kretprobes.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
+
+ .text
+
+ .macro save_all_base_regs
+ stp x0, x1, [sp, #S_X0]
+ stp x2, x3, [sp, #S_X2]
+ stp x4, x5, [sp, #S_X4]
+ stp x6, x7, [sp, #S_X6]
+ stp x8, x9, [sp, #S_X8]
+ stp x10, x11, [sp, #S_X10]
+ stp x12, x13, [sp, #S_X12]
+ stp x14, x15, [sp, #S_X14]
+ stp x16, x17, [sp, #S_X16]
+ stp x18, x19, [sp, #S_X18]
+ stp x20, x21, [sp, #S_X20]
+ stp x22, x23, [sp, #S_X22]
+ stp x24, x25, [sp, #S_X24]
+ stp x26, x27, [sp, #S_X26]
+ stp x28, x29, [sp, #S_X28]
+ add x0, sp, #PT_REGS_SIZE
+ stp lr, x0, [sp, #S_LR]
+ /*
+ * Construct a useful saved PSTATE
+ */
+ mrs x0, nzcv
+ mrs x1, daif
+ orr x0, x0, x1
+ mrs x1, CurrentEL
+ orr x0, x0, x1
+ mrs x1, SPSel
+ orr x0, x0, x1
+ stp xzr, x0, [sp, #S_PC]
+ .endm
+
+ .macro restore_all_base_regs
+ ldr x0, [sp, #S_PSTATE]
+ and x0, x0, #(PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT)
+ msr nzcv, x0
+ ldp x0, x1, [sp, #S_X0]
+ ldp x2, x3, [sp, #S_X2]
+ ldp x4, x5, [sp, #S_X4]
+ ldp x6, x7, [sp, #S_X6]
+ ldp x8, x9, [sp, #S_X8]
+ ldp x10, x11, [sp, #S_X10]
+ ldp x12, x13, [sp, #S_X12]
+ ldp x14, x15, [sp, #S_X14]
+ ldp x16, x17, [sp, #S_X16]
+ ldp x18, x19, [sp, #S_X18]
+ ldp x20, x21, [sp, #S_X20]
+ ldp x22, x23, [sp, #S_X22]
+ ldp x24, x25, [sp, #S_X24]
+ ldp x26, x27, [sp, #S_X26]
+ ldp x28, x29, [sp, #S_X28]
+ .endm
+
+SYM_CODE_START(__kretprobe_trampoline)
+ sub sp, sp, #PT_REGS_SIZE
+
+ save_all_base_regs
+
+ /* Setup a frame pointer. */
+ add x29, sp, #S_FP
+
+ mov x0, sp
+ bl trampoline_probe_handler
+ /*
+ * Replace trampoline address in lr with actual orig_ret_addr return
+ * address.
+ */
+ mov lr, x0
+
+ /* The frame pointer (x29) is restored with other registers. */
+ restore_all_base_regs
+
+ add sp, sp, #PT_REGS_SIZE
+ ret
+
+SYM_CODE_END(__kretprobe_trampoline)
diff --git a/arch/arm64/kernel/probes/simulate-insn.c b/arch/arm64/kernel/probes/simulate-insn.c
new file mode 100644
index 000000000..22d0b3252
--- /dev/null
+++ b/arch/arm64/kernel/probes/simulate-insn.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/arm64/kernel/probes/simulate-insn.c
+ *
+ * Copyright (C) 2013 Linaro Limited.
+ */
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+
+#include <asm/ptrace.h>
+#include <asm/traps.h>
+
+#include "simulate-insn.h"
+
+#define bbl_displacement(insn) \
+ sign_extend32(((insn) & 0x3ffffff) << 2, 27)
+
+#define bcond_displacement(insn) \
+ sign_extend32(((insn >> 5) & 0x7ffff) << 2, 20)
+
+#define cbz_displacement(insn) \
+ sign_extend32(((insn >> 5) & 0x7ffff) << 2, 20)
+
+#define tbz_displacement(insn) \
+ sign_extend32(((insn >> 5) & 0x3fff) << 2, 15)
+
+#define ldr_displacement(insn) \
+ sign_extend32(((insn >> 5) & 0x7ffff) << 2, 20)
+
+static inline void set_x_reg(struct pt_regs *regs, int reg, u64 val)
+{
+ pt_regs_write_reg(regs, reg, val);
+}
+
+static inline void set_w_reg(struct pt_regs *regs, int reg, u64 val)
+{
+ pt_regs_write_reg(regs, reg, lower_32_bits(val));
+}
+
+static inline u64 get_x_reg(struct pt_regs *regs, int reg)
+{
+ return pt_regs_read_reg(regs, reg);
+}
+
+static inline u32 get_w_reg(struct pt_regs *regs, int reg)
+{
+ return lower_32_bits(pt_regs_read_reg(regs, reg));
+}
+
+static bool __kprobes check_cbz(u32 opcode, struct pt_regs *regs)
+{
+ int xn = opcode & 0x1f;
+
+ return (opcode & (1 << 31)) ?
+ (get_x_reg(regs, xn) == 0) : (get_w_reg(regs, xn) == 0);
+}
+
+static bool __kprobes check_cbnz(u32 opcode, struct pt_regs *regs)
+{
+ int xn = opcode & 0x1f;
+
+ return (opcode & (1 << 31)) ?
+ (get_x_reg(regs, xn) != 0) : (get_w_reg(regs, xn) != 0);
+}
+
+static bool __kprobes check_tbz(u32 opcode, struct pt_regs *regs)
+{
+ int xn = opcode & 0x1f;
+ int bit_pos = ((opcode & (1 << 31)) >> 26) | ((opcode >> 19) & 0x1f);
+
+ return ((get_x_reg(regs, xn) >> bit_pos) & 0x1) == 0;
+}
+
+static bool __kprobes check_tbnz(u32 opcode, struct pt_regs *regs)
+{
+ int xn = opcode & 0x1f;
+ int bit_pos = ((opcode & (1 << 31)) >> 26) | ((opcode >> 19) & 0x1f);
+
+ return ((get_x_reg(regs, xn) >> bit_pos) & 0x1) != 0;
+}
+
+/*
+ * instruction simulation functions
+ */
+void __kprobes
+simulate_adr_adrp(u32 opcode, long addr, struct pt_regs *regs)
+{
+ long imm, xn, val;
+
+ xn = opcode & 0x1f;
+ imm = ((opcode >> 3) & 0x1ffffc) | ((opcode >> 29) & 0x3);
+ imm = sign_extend64(imm, 20);
+ if (opcode & 0x80000000)
+ val = (imm<<12) + (addr & 0xfffffffffffff000);
+ else
+ val = imm + addr;
+
+ set_x_reg(regs, xn, val);
+
+ instruction_pointer_set(regs, instruction_pointer(regs) + 4);
+}
+
+void __kprobes
+simulate_b_bl(u32 opcode, long addr, struct pt_regs *regs)
+{
+ int disp = bbl_displacement(opcode);
+
+ /* Link register is x30 */
+ if (opcode & (1 << 31))
+ set_x_reg(regs, 30, addr + 4);
+
+ instruction_pointer_set(regs, addr + disp);
+}
+
+void __kprobes
+simulate_b_cond(u32 opcode, long addr, struct pt_regs *regs)
+{
+ int disp = 4;
+
+ if (aarch32_opcode_cond_checks[opcode & 0xf](regs->pstate & 0xffffffff))
+ disp = bcond_displacement(opcode);
+
+ instruction_pointer_set(regs, addr + disp);
+}
+
+void __kprobes
+simulate_br_blr_ret(u32 opcode, long addr, struct pt_regs *regs)
+{
+ int xn = (opcode >> 5) & 0x1f;
+
+ /* update pc first in case we're doing a "blr lr" */
+ instruction_pointer_set(regs, get_x_reg(regs, xn));
+
+ /* Link register is x30 */
+ if (((opcode >> 21) & 0x3) == 1)
+ set_x_reg(regs, 30, addr + 4);
+}
+
+void __kprobes
+simulate_cbz_cbnz(u32 opcode, long addr, struct pt_regs *regs)
+{
+ int disp = 4;
+
+ if (opcode & (1 << 24)) {
+ if (check_cbnz(opcode, regs))
+ disp = cbz_displacement(opcode);
+ } else {
+ if (check_cbz(opcode, regs))
+ disp = cbz_displacement(opcode);
+ }
+ instruction_pointer_set(regs, addr + disp);
+}
+
+void __kprobes
+simulate_tbz_tbnz(u32 opcode, long addr, struct pt_regs *regs)
+{
+ int disp = 4;
+
+ if (opcode & (1 << 24)) {
+ if (check_tbnz(opcode, regs))
+ disp = tbz_displacement(opcode);
+ } else {
+ if (check_tbz(opcode, regs))
+ disp = tbz_displacement(opcode);
+ }
+ instruction_pointer_set(regs, addr + disp);
+}
+
+void __kprobes
+simulate_ldr_literal(u32 opcode, long addr, struct pt_regs *regs)
+{
+ u64 *load_addr;
+ int xn = opcode & 0x1f;
+ int disp;
+
+ disp = ldr_displacement(opcode);
+ load_addr = (u64 *) (addr + disp);
+
+ if (opcode & (1 << 30)) /* x0-x30 */
+ set_x_reg(regs, xn, *load_addr);
+ else /* w0-w30 */
+ set_w_reg(regs, xn, *load_addr);
+
+ instruction_pointer_set(regs, instruction_pointer(regs) + 4);
+}
+
+void __kprobes
+simulate_ldrsw_literal(u32 opcode, long addr, struct pt_regs *regs)
+{
+ s32 *load_addr;
+ int xn = opcode & 0x1f;
+ int disp;
+
+ disp = ldr_displacement(opcode);
+ load_addr = (s32 *) (addr + disp);
+
+ set_x_reg(regs, xn, *load_addr);
+
+ instruction_pointer_set(regs, instruction_pointer(regs) + 4);
+}
diff --git a/arch/arm64/kernel/probes/simulate-insn.h b/arch/arm64/kernel/probes/simulate-insn.h
new file mode 100644
index 000000000..e065dc922
--- /dev/null
+++ b/arch/arm64/kernel/probes/simulate-insn.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * arch/arm64/kernel/probes/simulate-insn.h
+ *
+ * Copyright (C) 2013 Linaro Limited
+ */
+
+#ifndef _ARM_KERNEL_KPROBES_SIMULATE_INSN_H
+#define _ARM_KERNEL_KPROBES_SIMULATE_INSN_H
+
+void simulate_adr_adrp(u32 opcode, long addr, struct pt_regs *regs);
+void simulate_b_bl(u32 opcode, long addr, struct pt_regs *regs);
+void simulate_b_cond(u32 opcode, long addr, struct pt_regs *regs);
+void simulate_br_blr_ret(u32 opcode, long addr, struct pt_regs *regs);
+void simulate_cbz_cbnz(u32 opcode, long addr, struct pt_regs *regs);
+void simulate_tbz_tbnz(u32 opcode, long addr, struct pt_regs *regs);
+void simulate_ldr_literal(u32 opcode, long addr, struct pt_regs *regs);
+void simulate_ldrsw_literal(u32 opcode, long addr, struct pt_regs *regs);
+
+#endif /* _ARM_KERNEL_KPROBES_SIMULATE_INSN_H */
diff --git a/arch/arm64/kernel/probes/uprobes.c b/arch/arm64/kernel/probes/uprobes.c
new file mode 100644
index 000000000..d49aef265
--- /dev/null
+++ b/arch/arm64/kernel/probes/uprobes.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2014-2016 Pratyush Anand <panand@redhat.com>
+ */
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/uprobes.h>
+#include <asm/cacheflush.h>
+
+#include "decode-insn.h"
+
+#define UPROBE_INV_FAULT_CODE UINT_MAX
+
+void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
+ void *src, unsigned long len)
+{
+ void *xol_page_kaddr = kmap_atomic(page);
+ void *dst = xol_page_kaddr + (vaddr & ~PAGE_MASK);
+
+ /* Initialize the slot */
+ memcpy(dst, src, len);
+
+ /* flush caches (dcache/icache) */
+ sync_icache_aliases((unsigned long)dst, (unsigned long)dst + len);
+
+ kunmap_atomic(xol_page_kaddr);
+}
+
+unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
+{
+ return instruction_pointer(regs);
+}
+
+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
+ unsigned long addr)
+{
+ probe_opcode_t insn;
+
+ /* TODO: Currently we do not support AARCH32 instruction probing */
+ if (mm->context.flags & MMCF_AARCH32)
+ return -EOPNOTSUPP;
+ else if (!IS_ALIGNED(addr, AARCH64_INSN_SIZE))
+ return -EINVAL;
+
+ insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+
+ switch (arm_probe_decode_insn(insn, &auprobe->api)) {
+ case INSN_REJECTED:
+ return -EINVAL;
+
+ case INSN_GOOD_NO_SLOT:
+ auprobe->simulate = true;
+ break;
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ /* Initialize with an invalid fault code to detect if ol insn trapped */
+ current->thread.fault_code = UPROBE_INV_FAULT_CODE;
+
+ /* Instruction points to execute ol */
+ instruction_pointer_set(regs, utask->xol_vaddr);
+
+ user_enable_single_step(current);
+
+ return 0;
+}
+
+int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ WARN_ON_ONCE(current->thread.fault_code != UPROBE_INV_FAULT_CODE);
+
+ /* Instruction points to execute next to breakpoint address */
+ instruction_pointer_set(regs, utask->vaddr + 4);
+
+ user_disable_single_step(current);
+
+ return 0;
+}
+bool arch_uprobe_xol_was_trapped(struct task_struct *t)
+{
+ /*
+ * Between arch_uprobe_pre_xol and arch_uprobe_post_xol, if an xol
+ * insn itself is trapped, then detect the case with the help of
+ * invalid fault code which is being set in arch_uprobe_pre_xol
+ */
+ if (t->thread.fault_code != UPROBE_INV_FAULT_CODE)
+ return true;
+
+ return false;
+}
+
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ probe_opcode_t insn;
+ unsigned long addr;
+
+ if (!auprobe->simulate)
+ return false;
+
+ insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+ addr = instruction_pointer(regs);
+
+ if (auprobe->api.handler)
+ auprobe->api.handler(insn, addr, regs);
+
+ return true;
+}
+
+void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ /*
+ * Task has received a fatal signal, so reset back to probbed
+ * address.
+ */
+ instruction_pointer_set(regs, utask->vaddr);
+
+ user_disable_single_step(current);
+}
+
+bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx,
+ struct pt_regs *regs)
+{
+ /*
+ * If a simple branch instruction (B) was called for retprobed
+ * assembly label then return true even when regs->sp and ret->stack
+ * are same. It will ensure that cleanup and reporting of return
+ * instances corresponding to callee label is done when
+ * handle_trampoline for called function is executed.
+ */
+ if (ctx == RP_CHECK_CHAIN_CALL)
+ return regs->sp <= ret->stack;
+ else
+ return regs->sp < ret->stack;
+}
+
+unsigned long
+arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
+ struct pt_regs *regs)
+{
+ unsigned long orig_ret_vaddr;
+
+ orig_ret_vaddr = procedure_link_pointer(regs);
+ /* Replace the return addr with trampoline addr */
+ procedure_link_pointer_set(regs, trampoline_vaddr);
+
+ return orig_ret_vaddr;
+}
+
+int arch_uprobe_exception_notify(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ return NOTIFY_DONE;
+}
+
+static int uprobe_breakpoint_handler(struct pt_regs *regs,
+ unsigned long esr)
+{
+ if (uprobe_pre_sstep_notifier(regs))
+ return DBG_HOOK_HANDLED;
+
+ return DBG_HOOK_ERROR;
+}
+
+static int uprobe_single_step_handler(struct pt_regs *regs,
+ unsigned long esr)
+{
+ struct uprobe_task *utask = current->utask;
+
+ WARN_ON(utask && (instruction_pointer(regs) != utask->xol_vaddr + 4));
+ if (uprobe_post_sstep_notifier(regs))
+ return DBG_HOOK_HANDLED;
+
+ return DBG_HOOK_ERROR;
+}
+
+/* uprobe breakpoint handler hook */
+static struct break_hook uprobes_break_hook = {
+ .imm = UPROBES_BRK_IMM,
+ .fn = uprobe_breakpoint_handler,
+};
+
+/* uprobe single step handler hook */
+static struct step_hook uprobes_step_hook = {
+ .fn = uprobe_single_step_handler,
+};
+
+static int __init arch_init_uprobes(void)
+{
+ register_user_break_hook(&uprobes_break_hook);
+ register_user_step_hook(&uprobes_step_hook);
+
+ return 0;
+}
+
+device_initcall(arch_init_uprobes);