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().
  ...

1 files changed, 452 insertions, 0 deletions

diff --git a/arch/sh/kernel/kprobes.c b/arch/sh/kernel/kprobes.c
new file mode 100644
index 000000000..aed1ea8e2
--- /dev/null
+++ b/arch/sh/kernel/kprobes.c
@@ -0,0 +1,452 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kernel probes (kprobes) for SuperH
+ *
+ * Copyright (C) 2007 Chris Smith <chris.smith@st.com>
+ * Copyright (C) 2006 Lineo Solutions, Inc.
+ */
+#include <linux/kprobes.h>
+#include <linux/extable.h>
+#include <linux/ptrace.h>
+#include <linux/preempt.h>
+#include <linux/kdebug.h>
+#include <linux/slab.h>
+#include <asm/cacheflush.h>
+#include <linux/uaccess.h>
+
+DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+
+static DEFINE_PER_CPU(struct kprobe, saved_current_opcode);
+static DEFINE_PER_CPU(struct kprobe, saved_next_opcode);
+static DEFINE_PER_CPU(struct kprobe, saved_next_opcode2);
+
+#define OPCODE_JMP(x)	(((x) & 0xF0FF) == 0x402b)
+#define OPCODE_JSR(x)	(((x) & 0xF0FF) == 0x400b)
+#define OPCODE_BRA(x)	(((x) & 0xF000) == 0xa000)
+#define OPCODE_BRAF(x)	(((x) & 0xF0FF) == 0x0023)
+#define OPCODE_BSR(x)	(((x) & 0xF000) == 0xb000)
+#define OPCODE_BSRF(x)	(((x) & 0xF0FF) == 0x0003)
+
+#define OPCODE_BF_S(x)	(((x) & 0xFF00) == 0x8f00)
+#define OPCODE_BT_S(x)	(((x) & 0xFF00) == 0x8d00)
+
+#define OPCODE_BF(x)	(((x) & 0xFF00) == 0x8b00)
+#define OPCODE_BT(x)	(((x) & 0xFF00) == 0x8900)
+
+#define OPCODE_RTS(x)	(((x) & 0x000F) == 0x000b)
+#define OPCODE_RTE(x)	(((x) & 0xFFFF) == 0x002b)
+
+int __kprobes arch_prepare_kprobe(struct kprobe *p)
+{
+	kprobe_opcode_t opcode = *(kprobe_opcode_t *) (p->addr);
+
+	if (OPCODE_RTE(opcode))
+		return -EFAULT;	/* Bad breakpoint */
+
+	p->opcode = opcode;
+
+	return 0;
+}
+
+void __kprobes arch_copy_kprobe(struct kprobe *p)
+{
+	memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
+	p->opcode = *p->addr;
+}
+
+void __kprobes arch_arm_kprobe(struct kprobe *p)
+{
+	*p->addr = BREAKPOINT_INSTRUCTION;
+	flush_icache_range((unsigned long)p->addr,
+			   (unsigned long)p->addr + sizeof(kprobe_opcode_t));
+}
+
+void __kprobes arch_disarm_kprobe(struct kprobe *p)
+{
+	*p->addr = p->opcode;
+	flush_icache_range((unsigned long)p->addr,
+			   (unsigned long)p->addr + sizeof(kprobe_opcode_t));
+}
+
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+{
+	if (*p->addr == BREAKPOINT_INSTRUCTION)
+		return 1;
+
+	return 0;
+}
+
+/**
+ * If an illegal slot instruction exception occurs for an address
+ * containing a kprobe, remove the probe.
+ *
+ * Returns 0 if the exception was handled successfully, 1 otherwise.
+ */
+int __kprobes kprobe_handle_illslot(unsigned long pc)
+{
+	struct kprobe *p = get_kprobe((kprobe_opcode_t *) pc + 1);
+
+	if (p != NULL) {
+		printk("Warning: removing kprobe from delay slot: 0x%.8x\n",
+		       (unsigned int)pc + 2);
+		unregister_kprobe(p);
+		return 0;
+	}
+
+	return 1;
+}
+
+void __kprobes arch_remove_kprobe(struct kprobe *p)
+{
+	struct kprobe *saved = this_cpu_ptr(&saved_next_opcode);
+
+	if (saved->addr) {
+		arch_disarm_kprobe(p);
+		arch_disarm_kprobe(saved);
+
+		saved->addr = NULL;
+		saved->opcode = 0;
+
+		saved = this_cpu_ptr(&saved_next_opcode2);
+		if (saved->addr) {
+			arch_disarm_kprobe(saved);
+
+			saved->addr = NULL;
+			saved->opcode = 0;
+		}
+	}
+}
+
+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, struct pt_regs *regs,
+					 struct kprobe_ctlblk *kcb)
+{
+	__this_cpu_write(current_kprobe, p);
+}
+
+/*
+ * Singlestep is implemented by disabling the current kprobe and setting one
+ * on the next instruction, following branches. Two probes are set if the
+ * branch is conditional.
+ */
+static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
+{
+	__this_cpu_write(saved_current_opcode.addr, (kprobe_opcode_t *)regs->pc);
+
+	if (p != NULL) {
+		struct kprobe *op1, *op2;
+
+		arch_disarm_kprobe(p);
+
+		op1 = this_cpu_ptr(&saved_next_opcode);
+		op2 = this_cpu_ptr(&saved_next_opcode2);
+
+		if (OPCODE_JSR(p->opcode) || OPCODE_JMP(p->opcode)) {
+			unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
+			op1->addr = (kprobe_opcode_t *) regs->regs[reg_nr];
+		} else if (OPCODE_BRA(p->opcode) || OPCODE_BSR(p->opcode)) {
+			unsigned long disp = (p->opcode & 0x0FFF);
+			op1->addr =
+			    (kprobe_opcode_t *) (regs->pc + 4 + disp * 2);
+
+		} else if (OPCODE_BRAF(p->opcode) || OPCODE_BSRF(p->opcode)) {
+			unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
+			op1->addr =
+			    (kprobe_opcode_t *) (regs->pc + 4 +
+						 regs->regs[reg_nr]);
+
+		} else if (OPCODE_RTS(p->opcode)) {
+			op1->addr = (kprobe_opcode_t *) regs->pr;
+
+		} else if (OPCODE_BF(p->opcode) || OPCODE_BT(p->opcode)) {
+			unsigned long disp = (p->opcode & 0x00FF);
+			/* case 1 */
+			op1->addr = p->addr + 1;
+			/* case 2 */
+			op2->addr =
+			    (kprobe_opcode_t *) (regs->pc + 4 + disp * 2);
+			op2->opcode = *(op2->addr);
+			arch_arm_kprobe(op2);
+
+		} else if (OPCODE_BF_S(p->opcode) || OPCODE_BT_S(p->opcode)) {
+			unsigned long disp = (p->opcode & 0x00FF);
+			/* case 1 */
+			op1->addr = p->addr + 2;
+			/* case 2 */
+			op2->addr =
+			    (kprobe_opcode_t *) (regs->pc + 4 + disp * 2);
+			op2->opcode = *(op2->addr);
+			arch_arm_kprobe(op2);
+
+		} else {
+			op1->addr = p->addr + 1;
+		}
+
+		op1->opcode = *(op1->addr);
+		arch_arm_kprobe(op1);
+	}
+}
+
+/* Called with kretprobe_lock held */
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
+				      struct pt_regs *regs)
+{
+	ri->ret_addr = (kprobe_opcode_t *) regs->pr;
+	ri->fp = NULL;
+
+	/* Replace the return addr with trampoline addr */
+	regs->pr = (unsigned long)__kretprobe_trampoline;
+}
+
+static int __kprobes kprobe_handler(struct pt_regs *regs)
+{
+	struct kprobe *p;
+	int ret = 0;
+	kprobe_opcode_t *addr = NULL;
+	struct kprobe_ctlblk *kcb;
+
+	/*
+	 * We don't want to be preempted for the entire
+	 * duration of kprobe processing
+	 */
+	preempt_disable();
+	kcb = get_kprobe_ctlblk();
+
+	addr = (kprobe_opcode_t *) (regs->pc);
+
+	/* Check we're not actually recursing */
+	if (kprobe_running()) {
+		p = get_kprobe(addr);
+		if (p) {
+			if (kcb->kprobe_status == KPROBE_HIT_SS &&
+			    *p->ainsn.insn == BREAKPOINT_INSTRUCTION) {
+				goto no_kprobe;
+			}
+			/* We have reentered the kprobe_handler(), since
+			 * another probe was hit while within the handler.
+			 * We here save the original kprobes variables and
+			 * just single step on the instruction of the new probe
+			 * without calling any user handlers.
+			 */
+			save_previous_kprobe(kcb);
+			set_current_kprobe(p, regs, kcb);
+			kprobes_inc_nmissed_count(p);
+			prepare_singlestep(p, regs);
+			kcb->kprobe_status = KPROBE_REENTER;
+			return 1;
+		}
+		goto no_kprobe;
+	}
+
+	p = get_kprobe(addr);
+	if (!p) {
+		/* Not one of ours: let kernel handle it */
+		if (*(kprobe_opcode_t *)addr != BREAKPOINT_INSTRUCTION) {
+			/*
+			 * The breakpoint instruction was removed right
+			 * after we hit it. Another cpu has removed
+			 * either a probepoint or a debugger breakpoint
+			 * at this address. In either case, no further
+			 * handling of this interrupt is appropriate.
+			 */
+			ret = 1;
+		}
+
+		goto no_kprobe;
+	}
+
+	set_current_kprobe(p, regs, kcb);
+	kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+	if (p->pre_handler && p->pre_handler(p, regs)) {
+		/* handler has already set things up, so skip ss setup */
+		reset_current_kprobe();
+		preempt_enable_no_resched();
+		return 1;
+	}
+
+	prepare_singlestep(p, regs);
+	kcb->kprobe_status = KPROBE_HIT_SS;
+	return 1;
+
+no_kprobe:
+	preempt_enable_no_resched();
+	return ret;
+}
+
+/*
+ * For function-return probes, init_kprobes() establishes a probepoint
+ * here. When a retprobed function returns, this probe is hit and
+ * trampoline_probe_handler() runs, calling the kretprobe's handler.
+ */
+static void __used kretprobe_trampoline_holder(void)
+{
+	asm volatile (".globl __kretprobe_trampoline\n"
+		      "__kretprobe_trampoline:\n\t"
+		      "nop\n");
+}
+
+/*
+ * Called when we hit the probe point at __kretprobe_trampoline
+ */
+int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+{
+	regs->pc = __kretprobe_trampoline_handler(regs, NULL);
+
+	return 1;
+}
+
+static int __kprobes post_kprobe_handler(struct pt_regs *regs)
+{
+	struct kprobe *cur = kprobe_running();
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	kprobe_opcode_t *addr = NULL;
+	struct kprobe *p = NULL;
+
+	if (!cur)
+		return 0;
+
+	if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
+		kcb->kprobe_status = KPROBE_HIT_SSDONE;
+		cur->post_handler(cur, regs, 0);
+	}
+
+	p = this_cpu_ptr(&saved_next_opcode);
+	if (p->addr) {
+		arch_disarm_kprobe(p);
+		p->addr = NULL;
+		p->opcode = 0;
+
+		addr = __this_cpu_read(saved_current_opcode.addr);
+		__this_cpu_write(saved_current_opcode.addr, NULL);
+
+		p = get_kprobe(addr);
+		arch_arm_kprobe(p);
+
+		p = this_cpu_ptr(&saved_next_opcode2);
+		if (p->addr) {
+			arch_disarm_kprobe(p);
+			p->addr = NULL;
+			p->opcode = 0;
+		}
+	}
+
+	/* Restore back the original saved kprobes variables and continue. */
+	if (kcb->kprobe_status == KPROBE_REENTER) {
+		restore_previous_kprobe(kcb);
+		goto out;
+	}
+
+	reset_current_kprobe();
+
+out:
+	preempt_enable_no_resched();
+
+	return 1;
+}
+
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+{
+	struct kprobe *cur = kprobe_running();
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	const struct exception_table_entry *entry;
+
+	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, point the pc back to the probe address
+		 * and allow the page fault handler to continue as a
+		 * normal page fault.
+		 */
+		regs->pc = (unsigned long)cur->addr;
+		if (kcb->kprobe_status == KPROBE_REENTER)
+			restore_previous_kprobe(kcb);
+		else
+			reset_current_kprobe();
+		preempt_enable_no_resched();
+		break;
+	case KPROBE_HIT_ACTIVE:
+	case KPROBE_HIT_SSDONE:
+		/*
+		 * In case the user-specified fault handler returned
+		 * zero, try to fix up.
+		 */
+		if ((entry = search_exception_tables(regs->pc)) != NULL) {
+			regs->pc = entry->fixup;
+			return 1;
+		}
+
+		/*
+		 * fixup_exception() could not handle it,
+		 * Let do_page_fault() fix it.
+		 */
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * Wrapper routine to for handling exceptions.
+ */
+int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
+				       unsigned long val, void *data)
+{
+	struct kprobe *p = NULL;
+	struct die_args *args = (struct die_args *)data;
+	int ret = NOTIFY_DONE;
+	kprobe_opcode_t *addr = NULL;
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+
+	addr = (kprobe_opcode_t *) (args->regs->pc);
+	if (val == DIE_TRAP &&
+	    args->trapnr == (BREAKPOINT_INSTRUCTION & 0xff)) {
+		if (!kprobe_running()) {
+			if (kprobe_handler(args->regs)) {
+				ret = NOTIFY_STOP;
+			} else {
+				/* Not a kprobe trap */
+				ret = NOTIFY_DONE;
+			}
+		} else {
+			p = get_kprobe(addr);
+			if ((kcb->kprobe_status == KPROBE_HIT_SS) ||
+			    (kcb->kprobe_status == KPROBE_REENTER)) {
+				if (post_kprobe_handler(args->regs))
+					ret = NOTIFY_STOP;
+			} else {
+				if (kprobe_handler(args->regs))
+					ret = NOTIFY_STOP;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static struct kprobe trampoline_p = {
+	.addr = (kprobe_opcode_t *)&__kretprobe_trampoline,
+	.pre_handler = trampoline_probe_handler
+};
+
+int __init arch_init_kprobes(void)
+{
+	return register_kprobe(&trampoline_p);
+}