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, 525 insertions, 0 deletions

diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
new file mode 100644
index 000000000..5e713f318
--- /dev/null
+++ b/arch/s390/kernel/kprobes.c
@@ -0,0 +1,525 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Kernel Probes (KProbes)
+ *
+ * Copyright IBM Corp. 2002, 2006
+ *
+ * s390 port, used ppc64 as template. Mike Grundy <grundym@us.ibm.com>
+ */
+
+#define pr_fmt(fmt) "kprobes: " fmt
+
+#include <linux/moduleloader.h>
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+#include <linux/preempt.h>
+#include <linux/stop_machine.h>
+#include <linux/kdebug.h>
+#include <linux/uaccess.h>
+#include <linux/extable.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/hardirq.h>
+#include <linux/ftrace.h>
+#include <asm/set_memory.h>
+#include <asm/sections.h>
+#include <asm/dis.h>
+#include "kprobes.h"
+#include "entry.h"
+
+DEFINE_PER_CPU(struct kprobe *, current_kprobe);
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+
+struct kretprobe_blackpoint kretprobe_blacklist[] = { };
+
+static int insn_page_in_use;
+
+void *alloc_insn_page(void)
+{
+	void *page;
+
+	page = module_alloc(PAGE_SIZE);
+	if (!page)
+		return NULL;
+	__set_memory((unsigned long) page, 1, SET_MEMORY_RO | SET_MEMORY_X);
+	return page;
+}
+
+static void *alloc_s390_insn_page(void)
+{
+	if (xchg(&insn_page_in_use, 1) == 1)
+		return NULL;
+	return &kprobes_insn_page;
+}
+
+static void free_s390_insn_page(void *page)
+{
+	xchg(&insn_page_in_use, 0);
+}
+
+struct kprobe_insn_cache kprobe_s390_insn_slots = {
+	.mutex = __MUTEX_INITIALIZER(kprobe_s390_insn_slots.mutex),
+	.alloc = alloc_s390_insn_page,
+	.free = free_s390_insn_page,
+	.pages = LIST_HEAD_INIT(kprobe_s390_insn_slots.pages),
+	.insn_size = MAX_INSN_SIZE,
+};
+
+static void copy_instruction(struct kprobe *p)
+{
+	kprobe_opcode_t insn[MAX_INSN_SIZE];
+	s64 disp, new_disp;
+	u64 addr, new_addr;
+	unsigned int len;
+
+	len = insn_length(*p->addr >> 8);
+	memcpy(&insn, p->addr, len);
+	p->opcode = insn[0];
+	if (probe_is_insn_relative_long(&insn[0])) {
+		/*
+		 * For pc-relative instructions in RIL-b or RIL-c format patch
+		 * the RI2 displacement field. We have already made sure that
+		 * the insn slot for the patched instruction is within the same
+		 * 2GB area as the original instruction (either kernel image or
+		 * module area). Therefore the new displacement will always fit.
+		 */
+		disp = *(s32 *)&insn[1];
+		addr = (u64)(unsigned long)p->addr;
+		new_addr = (u64)(unsigned long)p->ainsn.insn;
+		new_disp = ((addr + (disp * 2)) - new_addr) / 2;
+		*(s32 *)&insn[1] = new_disp;
+	}
+	s390_kernel_write(p->ainsn.insn, &insn, len);
+}
+NOKPROBE_SYMBOL(copy_instruction);
+
+static int s390_get_insn_slot(struct kprobe *p)
+{
+	/*
+	 * Get an insn slot that is within the same 2GB area like the original
+	 * instruction. That way instructions with a 32bit signed displacement
+	 * field can be patched and executed within the insn slot.
+	 */
+	p->ainsn.insn = NULL;
+	if (is_kernel((unsigned long)p->addr))
+		p->ainsn.insn = get_s390_insn_slot();
+	else if (is_module_addr(p->addr))
+		p->ainsn.insn = get_insn_slot();
+	return p->ainsn.insn ? 0 : -ENOMEM;
+}
+NOKPROBE_SYMBOL(s390_get_insn_slot);
+
+static void s390_free_insn_slot(struct kprobe *p)
+{
+	if (!p->ainsn.insn)
+		return;
+	if (is_kernel((unsigned long)p->addr))
+		free_s390_insn_slot(p->ainsn.insn, 0);
+	else
+		free_insn_slot(p->ainsn.insn, 0);
+	p->ainsn.insn = NULL;
+}
+NOKPROBE_SYMBOL(s390_free_insn_slot);
+
+/* Check if paddr is at an instruction boundary */
+static bool can_probe(unsigned long paddr)
+{
+	unsigned long addr, offset = 0;
+	kprobe_opcode_t insn;
+	struct kprobe *kp;
+
+	if (paddr & 0x01)
+		return false;
+
+	if (!kallsyms_lookup_size_offset(paddr, NULL, &offset))
+		return false;
+
+	/* Decode instructions */
+	addr = paddr - offset;
+	while (addr < paddr) {
+		if (copy_from_kernel_nofault(&insn, (void *)addr, sizeof(insn)))
+			return false;
+
+		if (insn >> 8 == 0) {
+			if (insn != BREAKPOINT_INSTRUCTION) {
+				/*
+				 * Note that QEMU inserts opcode 0x0000 to implement
+				 * software breakpoints for guests. Since the size of
+				 * the original instruction is unknown, stop following
+				 * instructions and prevent setting a kprobe.
+				 */
+				return false;
+			}
+			/*
+			 * Check if the instruction has been modified by another
+			 * kprobe, in which case the original instruction is
+			 * decoded.
+			 */
+			kp = get_kprobe((void *)addr);
+			if (!kp) {
+				/* not a kprobe */
+				return false;
+			}
+			insn = kp->opcode;
+		}
+		addr += insn_length(insn >> 8);
+	}
+	return addr == paddr;
+}
+
+int arch_prepare_kprobe(struct kprobe *p)
+{
+	if (!can_probe((unsigned long)p->addr))
+		return -EINVAL;
+	/* Make sure the probe isn't going on a difficult instruction */
+	if (probe_is_prohibited_opcode(p->addr))
+		return -EINVAL;
+	if (s390_get_insn_slot(p))
+		return -ENOMEM;
+	copy_instruction(p);
+	return 0;
+}
+NOKPROBE_SYMBOL(arch_prepare_kprobe);
+
+struct swap_insn_args {
+	struct kprobe *p;
+	unsigned int arm_kprobe : 1;
+};
+
+static int swap_instruction(void *data)
+{
+	struct swap_insn_args *args = data;
+	struct kprobe *p = args->p;
+	u16 opc;
+
+	opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode;
+	s390_kernel_write(p->addr, &opc, sizeof(opc));
+	return 0;
+}
+NOKPROBE_SYMBOL(swap_instruction);
+
+void arch_arm_kprobe(struct kprobe *p)
+{
+	struct swap_insn_args args = {.p = p, .arm_kprobe = 1};
+
+	stop_machine_cpuslocked(swap_instruction, &args, NULL);
+}
+NOKPROBE_SYMBOL(arch_arm_kprobe);
+
+void arch_disarm_kprobe(struct kprobe *p)
+{
+	struct swap_insn_args args = {.p = p, .arm_kprobe = 0};
+
+	stop_machine_cpuslocked(swap_instruction, &args, NULL);
+}
+NOKPROBE_SYMBOL(arch_disarm_kprobe);
+
+void arch_remove_kprobe(struct kprobe *p)
+{
+	s390_free_insn_slot(p);
+}
+NOKPROBE_SYMBOL(arch_remove_kprobe);
+
+static void enable_singlestep(struct kprobe_ctlblk *kcb,
+			      struct pt_regs *regs,
+			      unsigned long ip)
+{
+	struct per_regs per_kprobe;
+
+	/* Set up the PER control registers %cr9-%cr11 */
+	per_kprobe.control = PER_EVENT_IFETCH;
+	per_kprobe.start = ip;
+	per_kprobe.end = ip;
+
+	/* Save control regs and psw mask */
+	__ctl_store(kcb->kprobe_saved_ctl, 9, 11);
+	kcb->kprobe_saved_imask = regs->psw.mask &
+		(PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT);
+
+	/* Set PER control regs, turns on single step for the given address */
+	__ctl_load(per_kprobe, 9, 11);
+	regs->psw.mask |= PSW_MASK_PER;
+	regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
+	regs->psw.addr = ip;
+}
+NOKPROBE_SYMBOL(enable_singlestep);
+
+static void disable_singlestep(struct kprobe_ctlblk *kcb,
+			       struct pt_regs *regs,
+			       unsigned long ip)
+{
+	/* Restore control regs and psw mask, set new psw address */
+	__ctl_load(kcb->kprobe_saved_ctl, 9, 11);
+	regs->psw.mask &= ~PSW_MASK_PER;
+	regs->psw.mask |= kcb->kprobe_saved_imask;
+	regs->psw.addr = ip;
+}
+NOKPROBE_SYMBOL(disable_singlestep);
+
+/*
+ * Activate a kprobe by storing its pointer to current_kprobe. The
+ * previous kprobe is stored in kcb->prev_kprobe. A stack of up to
+ * two kprobes can be active, see KPROBE_REENTER.
+ */
+static void push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p)
+{
+	kcb->prev_kprobe.kp = __this_cpu_read(current_kprobe);
+	kcb->prev_kprobe.status = kcb->kprobe_status;
+	__this_cpu_write(current_kprobe, p);
+}
+NOKPROBE_SYMBOL(push_kprobe);
+
+/*
+ * Deactivate a kprobe by backing up to the previous state. If the
+ * current state is KPROBE_REENTER prev_kprobe.kp will be non-NULL,
+ * for any other state prev_kprobe.kp will be NULL.
+ */
+static void pop_kprobe(struct kprobe_ctlblk *kcb)
+{
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
+	kcb->kprobe_status = kcb->prev_kprobe.status;
+}
+NOKPROBE_SYMBOL(pop_kprobe);
+
+static void kprobe_reenter_check(struct kprobe_ctlblk *kcb, struct kprobe *p)
+{
+	switch (kcb->kprobe_status) {
+	case KPROBE_HIT_SSDONE:
+	case KPROBE_HIT_ACTIVE:
+		kprobes_inc_nmissed_count(p);
+		break;
+	case KPROBE_HIT_SS:
+	case KPROBE_REENTER:
+	default:
+		/*
+		 * A kprobe on the code path to single step an instruction
+		 * is a BUG. The code path resides in the .kprobes.text
+		 * section and is executed with interrupts disabled.
+		 */
+		pr_err("Failed to recover from reentered kprobes.\n");
+		dump_kprobe(p);
+		BUG();
+	}
+}
+NOKPROBE_SYMBOL(kprobe_reenter_check);
+
+static int kprobe_handler(struct pt_regs *regs)
+{
+	struct kprobe_ctlblk *kcb;
+	struct kprobe *p;
+
+	/*
+	 * We want to disable preemption for the entire duration of kprobe
+	 * processing. That includes the calls to the pre/post handlers
+	 * and single stepping the kprobe instruction.
+	 */
+	preempt_disable();
+	kcb = get_kprobe_ctlblk();
+	p = get_kprobe((void *)(regs->psw.addr - 2));
+
+	if (p) {
+		if (kprobe_running()) {
+			/*
+			 * We have hit a kprobe while another is still
+			 * active. This can happen in the pre and post
+			 * handler. Single step the instruction of the
+			 * new probe but do not call any handler function
+			 * of this secondary kprobe.
+			 * push_kprobe and pop_kprobe saves and restores
+			 * the currently active kprobe.
+			 */
+			kprobe_reenter_check(kcb, p);
+			push_kprobe(kcb, p);
+			kcb->kprobe_status = KPROBE_REENTER;
+		} else {
+			/*
+			 * If we have no pre-handler or it returned 0, we
+			 * continue with single stepping. If we have a
+			 * pre-handler and it returned non-zero, it prepped
+			 * for changing execution path, so get out doing
+			 * nothing more here.
+			 */
+			push_kprobe(kcb, p);
+			kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+			if (p->pre_handler && p->pre_handler(p, regs)) {
+				pop_kprobe(kcb);
+				preempt_enable_no_resched();
+				return 1;
+			}
+			kcb->kprobe_status = KPROBE_HIT_SS;
+		}
+		enable_singlestep(kcb, regs, (unsigned long) p->ainsn.insn);
+		return 1;
+	} /* else:
+	   * No kprobe at this address and no active kprobe. The trap has
+	   * not been caused by a kprobe breakpoint. The race of breakpoint
+	   * vs. kprobe remove does not exist because on s390 as we use
+	   * stop_machine to arm/disarm the breakpoints.
+	   */
+	preempt_enable_no_resched();
+	return 0;
+}
+NOKPROBE_SYMBOL(kprobe_handler);
+
+/*
+ * Called after single-stepping.  p->addr is the address of the
+ * instruction whose first byte has been replaced by the "breakpoint"
+ * instruction.  To avoid the SMP problems that can occur when we
+ * temporarily put back the original opcode to single-step, we
+ * single-stepped a copy of the instruction.  The address of this
+ * copy is p->ainsn.insn.
+ */
+static void resume_execution(struct kprobe *p, struct pt_regs *regs)
+{
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	unsigned long ip = regs->psw.addr;
+	int fixup = probe_get_fixup_type(p->ainsn.insn);
+
+	if (fixup & FIXUP_PSW_NORMAL)
+		ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn;
+
+	if (fixup & FIXUP_BRANCH_NOT_TAKEN) {
+		int ilen = insn_length(p->ainsn.insn[0] >> 8);
+		if (ip - (unsigned long) p->ainsn.insn == ilen)
+			ip = (unsigned long) p->addr + ilen;
+	}
+
+	if (fixup & FIXUP_RETURN_REGISTER) {
+		int reg = (p->ainsn.insn[0] & 0xf0) >> 4;
+		regs->gprs[reg] += (unsigned long) p->addr -
+				   (unsigned long) p->ainsn.insn;
+	}
+
+	disable_singlestep(kcb, regs, ip);
+}
+NOKPROBE_SYMBOL(resume_execution);
+
+static int post_kprobe_handler(struct pt_regs *regs)
+{
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	struct kprobe *p = kprobe_running();
+
+	if (!p)
+		return 0;
+
+	if (kcb->kprobe_status != KPROBE_REENTER && p->post_handler) {
+		kcb->kprobe_status = KPROBE_HIT_SSDONE;
+		p->post_handler(p, regs, 0);
+	}
+
+	resume_execution(p, regs);
+	pop_kprobe(kcb);
+	preempt_enable_no_resched();
+
+	/*
+	 * if somebody else is singlestepping across a probe point, psw mask
+	 * will have PER set, in which case, continue the remaining processing
+	 * of do_single_step, as if this is not a probe hit.
+	 */
+	if (regs->psw.mask & PSW_MASK_PER)
+		return 0;
+
+	return 1;
+}
+NOKPROBE_SYMBOL(post_kprobe_handler);
+
+static int kprobe_trap_handler(struct pt_regs *regs, int trapnr)
+{
+	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+	struct kprobe *p = kprobe_running();
+
+	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 nip points back to the probe address
+		 * and allow the page fault handler to continue as a
+		 * normal page fault.
+		 */
+		disable_singlestep(kcb, regs, (unsigned long) p->addr);
+		pop_kprobe(kcb);
+		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 (fixup_exception(regs))
+			return 1;
+		/*
+		 * fixup_exception() could not handle it,
+		 * Let do_page_fault() fix it.
+		 */
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+NOKPROBE_SYMBOL(kprobe_trap_handler);
+
+int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+{
+	int ret;
+
+	if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+		local_irq_disable();
+	ret = kprobe_trap_handler(regs, trapnr);
+	if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+		local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+	return ret;
+}
+NOKPROBE_SYMBOL(kprobe_fault_handler);
+
+/*
+ * Wrapper routine to for handling exceptions.
+ */
+int kprobe_exceptions_notify(struct notifier_block *self,
+			     unsigned long val, void *data)
+{
+	struct die_args *args = (struct die_args *) data;
+	struct pt_regs *regs = args->regs;
+	int ret = NOTIFY_DONE;
+
+	if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+		local_irq_disable();
+
+	switch (val) {
+	case DIE_BPT:
+		if (kprobe_handler(regs))
+			ret = NOTIFY_STOP;
+		break;
+	case DIE_SSTEP:
+		if (post_kprobe_handler(regs))
+			ret = NOTIFY_STOP;
+		break;
+	case DIE_TRAP:
+		if (!preemptible() && kprobe_running() &&
+		    kprobe_trap_handler(regs, args->trapnr))
+			ret = NOTIFY_STOP;
+		break;
+	default:
+		break;
+	}
+
+	if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+		local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+
+	return ret;
+}
+NOKPROBE_SYMBOL(kprobe_exceptions_notify);
+
+int __init arch_init_kprobes(void)
+{
+	return 0;
+}
+
+int arch_trampoline_kprobe(struct kprobe *p)
+{
+	return 0;
+}
+NOKPROBE_SYMBOL(arch_trampoline_kprobe);