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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /arch/arm64/kernel/probes | |
download | linux-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/Makefile | 6 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/decode-insn.c | 168 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/decode-insn.h | 33 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/kprobes.c | 425 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/kprobes_trampoline.S | 86 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/simulate-insn.c | 202 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/simulate-insn.h | 20 | ||||
-rw-r--r-- | arch/arm64/kernel/probes/uprobes.c | 208 |
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); |