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, 514 insertions, 0 deletions

diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c
new file mode 100644
index 000000000..876d5df15
--- /dev/null
+++ b/arch/xtensa/kernel/signal.c
@@ -0,0 +1,514 @@
+/*
+ * arch/xtensa/kernel/signal.c
+ *
+ * Default platform functions.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2005, 2006 Tensilica Inc.
+ * Copyright (C) 1991, 1992  Linus Torvalds
+ * 1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ *
+ * Chris Zankel <chris@zankel.net>
+ * Joe Taylor <joe@tensilica.com>
+ */
+
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/personality.h>
+#include <linux/resume_user_mode.h>
+#include <linux/sched/task_stack.h>
+
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/cacheflush.h>
+#include <asm/coprocessor.h>
+#include <asm/unistd.h>
+
+extern struct task_struct *coproc_owners[];
+
+struct rt_sigframe
+{
+	struct siginfo info;
+	struct ucontext uc;
+	struct {
+		xtregs_opt_t opt;
+		xtregs_user_t user;
+#if XTENSA_HAVE_COPROCESSORS
+		xtregs_coprocessor_t cp;
+#endif
+	} xtregs;
+	unsigned char retcode[6];
+	unsigned int window[4];
+};
+
+#if defined(USER_SUPPORT_WINDOWED)
+/*
+ * Flush register windows stored in pt_regs to stack.
+ * Returns 1 for errors.
+ */
+
+static int
+flush_window_regs_user(struct pt_regs *regs)
+{
+	const unsigned long ws = regs->windowstart;
+	const unsigned long wb = regs->windowbase;
+	unsigned long sp = 0;
+	unsigned long wm;
+	int err = 1;
+	int base;
+
+	/* Return if no other frames. */
+
+	if (regs->wmask == 1)
+		return 0;
+
+	/* Rotate windowmask and skip empty frames. */
+
+	wm = (ws >> wb) | (ws << (XCHAL_NUM_AREGS / 4 - wb));
+	base = (XCHAL_NUM_AREGS / 4) - (regs->wmask >> 4);
+		
+	/* For call8 or call12 frames, we need the previous stack pointer. */
+
+	if ((regs->wmask & 2) == 0)
+		if (__get_user(sp, (int*)(regs->areg[base * 4 + 1] - 12)))
+			goto errout;
+
+	/* Spill frames to stack. */
+
+	while (base < XCHAL_NUM_AREGS / 4) {
+
+		int m = (wm >> base);
+		int inc = 0;
+
+		/* Save registers a4..a7 (call8) or a4...a11 (call12) */
+
+		if (m & 2) {			/* call4 */
+			inc = 1;
+
+		} else if (m & 4) {		/* call8 */
+			if (copy_to_user(&SPILL_SLOT_CALL8(sp, 4),
+					 &regs->areg[(base + 1) * 4], 16))
+				goto errout;
+			inc = 2;
+
+		} else if (m & 8) {	/* call12 */
+			if (copy_to_user(&SPILL_SLOT_CALL12(sp, 4),
+					 &regs->areg[(base + 1) * 4], 32))
+				goto errout;
+			inc = 3;
+		}
+
+		/* Save current frame a0..a3 under next SP */
+
+		sp = regs->areg[((base + inc) * 4 + 1) % XCHAL_NUM_AREGS];
+		if (copy_to_user(&SPILL_SLOT(sp, 0), &regs->areg[base * 4], 16))
+			goto errout;
+
+		/* Get current stack pointer for next loop iteration. */
+
+		sp = regs->areg[base * 4 + 1];
+		base += inc;
+	}
+
+	regs->wmask = 1;
+	regs->windowstart = 1 << wb;
+
+	return 0;
+
+errout:
+	return err;
+}
+#else
+static int
+flush_window_regs_user(struct pt_regs *regs)
+{
+	return 0;
+}
+#endif
+
+/*
+ * Note: We don't copy double exception 'regs', we have to finish double exc. 
+ * first before we return to signal handler! This dbl.exc.handler might cause 
+ * another double exception, but I think we are fine as the situation is the 
+ * same as if we had returned to the signal handerl and got an interrupt 
+ * immediately...
+ */
+
+static int
+setup_sigcontext(struct rt_sigframe __user *frame, struct pt_regs *regs)
+{
+	struct sigcontext __user *sc = &frame->uc.uc_mcontext;
+	struct thread_info *ti = current_thread_info();
+	int err = 0;
+
+#define COPY(x)	err |= __put_user(regs->x, &sc->sc_##x)
+	COPY(pc);
+	COPY(ps);
+	COPY(lbeg);
+	COPY(lend);
+	COPY(lcount);
+	COPY(sar);
+#undef COPY
+
+	err |= flush_window_regs_user(regs);
+	err |= __copy_to_user (sc->sc_a, regs->areg, 16 * 4);
+	err |= __put_user(0, &sc->sc_xtregs);
+
+	if (err)
+		return err;
+
+#if XTENSA_HAVE_COPROCESSORS
+	coprocessor_flush_release_all(ti);
+	err |= __copy_to_user(&frame->xtregs.cp, &ti->xtregs_cp,
+			      sizeof (frame->xtregs.cp));
+#endif
+	err |= __copy_to_user(&frame->xtregs.opt, &regs->xtregs_opt,
+			      sizeof (xtregs_opt_t));
+	err |= __copy_to_user(&frame->xtregs.user, &ti->xtregs_user,
+			      sizeof (xtregs_user_t));
+
+	err |= __put_user(err ? NULL : &frame->xtregs, &sc->sc_xtregs);
+
+	return err;
+}
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct rt_sigframe __user *frame)
+{
+	struct sigcontext __user *sc = &frame->uc.uc_mcontext;
+	struct thread_info *ti = current_thread_info();
+	unsigned int err = 0;
+	unsigned long ps;
+
+#define COPY(x)	err |= __get_user(regs->x, &sc->sc_##x)
+	COPY(pc);
+	COPY(lbeg);
+	COPY(lend);
+	COPY(lcount);
+	COPY(sar);
+#undef COPY
+
+	/* All registers were flushed to stack. Start with a pristine frame. */
+
+	regs->wmask = 1;
+	regs->windowbase = 0;
+	regs->windowstart = 1;
+
+	regs->syscall = NO_SYSCALL;	/* disable syscall checks */
+
+	/* For PS, restore only PS.CALLINC.
+	 * Assume that all other bits are either the same as for the signal
+	 * handler, or the user mode value doesn't matter (e.g. PS.OWB).
+	 */
+	err |= __get_user(ps, &sc->sc_ps);
+	regs->ps = (regs->ps & ~PS_CALLINC_MASK) | (ps & PS_CALLINC_MASK);
+
+	/* Additional corruption checks */
+
+	if ((regs->lcount > 0)
+	    && ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) )
+		err = 1;
+
+	err |= __copy_from_user(regs->areg, sc->sc_a, 16 * 4);
+
+	if (err)
+		return err;
+
+	/* The signal handler may have used coprocessors in which
+	 * case they are still enabled.  We disable them to force a
+	 * reloading of the original task's CP state by the lazy
+	 * context-switching mechanisms of CP exception handling.
+	 * Also, we essentially discard any coprocessor state that the
+	 * signal handler created. */
+
+#if XTENSA_HAVE_COPROCESSORS
+	coprocessor_release_all(ti);
+	err |= __copy_from_user(&ti->xtregs_cp, &frame->xtregs.cp,
+				sizeof (frame->xtregs.cp));
+#endif
+	err |= __copy_from_user(&ti->xtregs_user, &frame->xtregs.user,
+				sizeof (xtregs_user_t));
+	err |= __copy_from_user(&regs->xtregs_opt, &frame->xtregs.opt,
+				sizeof (xtregs_opt_t));
+
+	return err;
+}
+
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+asmlinkage long xtensa_rt_sigreturn(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+	int ret;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (regs->depc > 64)
+		panic("rt_sigreturn in double exception!\n");
+
+	frame = (struct rt_sigframe __user *) regs->areg[1];
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(regs, frame))
+		goto badframe;
+
+	ret = regs->areg[2];
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return ret;
+
+badframe:
+	force_sig(SIGSEGV);
+	return 0;
+}
+
+
+
+/*
+ * Set up a signal frame.
+ */
+
+static int
+gen_return_code(unsigned char *codemem)
+{
+	int err = 0;
+
+	/*
+	 * The 12-bit immediate is really split up within the 24-bit MOVI
+	 * instruction.  As long as the above system call numbers fit within
+	 * 8-bits, the following code works fine. See the Xtensa ISA for
+	 * details.
+	 */
+
+#if __NR_rt_sigreturn > 255
+# error Generating the MOVI instruction below breaks!
+#endif
+
+#ifdef __XTENSA_EB__   /* Big Endian version */
+	/* Generate instruction:  MOVI a2, __NR_rt_sigreturn */
+	err |= __put_user(0x22, &codemem[0]);
+	err |= __put_user(0x0a, &codemem[1]);
+	err |= __put_user(__NR_rt_sigreturn, &codemem[2]);
+	/* Generate instruction:  SYSCALL */
+	err |= __put_user(0x00, &codemem[3]);
+	err |= __put_user(0x05, &codemem[4]);
+	err |= __put_user(0x00, &codemem[5]);
+
+#elif defined __XTENSA_EL__   /* Little Endian version */
+	/* Generate instruction:  MOVI a2, __NR_rt_sigreturn */
+	err |= __put_user(0x22, &codemem[0]);
+	err |= __put_user(0xa0, &codemem[1]);
+	err |= __put_user(__NR_rt_sigreturn, &codemem[2]);
+	/* Generate instruction:  SYSCALL */
+	err |= __put_user(0x00, &codemem[3]);
+	err |= __put_user(0x50, &codemem[4]);
+	err |= __put_user(0x00, &codemem[5]);
+#else
+# error Must use compiler for Xtensa processors.
+#endif
+
+	/* Flush generated code out of the data cache */
+
+	if (err == 0) {
+		__invalidate_icache_range((unsigned long)codemem, 6UL);
+		__flush_invalidate_dcache_range((unsigned long)codemem, 6UL);
+	}
+
+	return err;
+}
+
+
+static int setup_frame(struct ksignal *ksig, sigset_t *set,
+		       struct pt_regs *regs)
+{
+	struct rt_sigframe *frame;
+	int err = 0, sig = ksig->sig;
+	unsigned long sp, ra, tp, ps;
+	unsigned int base;
+
+	sp = regs->areg[1];
+
+	if ((ksig->ka.sa.sa_flags & SA_ONSTACK) != 0 && sas_ss_flags(sp) == 0) {
+		sp = current->sas_ss_sp + current->sas_ss_size;
+	}
+
+	frame = (void *)((sp - sizeof(*frame)) & -16ul);
+
+	if (regs->depc > 64)
+		panic ("Double exception sys_sigreturn\n");
+
+	if (!access_ok(frame, sizeof(*frame))) {
+		return -EFAULT;
+	}
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+	}
+
+	/* Create the user context.  */
+
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(0, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, regs->areg[1]);
+	err |= setup_sigcontext(frame, regs);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+		ra = (unsigned long)ksig->ka.sa.sa_restorer;
+	} else {
+
+		/* Create sys_rt_sigreturn syscall in stack frame */
+
+		err |= gen_return_code(frame->retcode);
+
+		if (err) {
+			return -EFAULT;
+		}
+		ra = (unsigned long) frame->retcode;
+	}
+
+	/* 
+	 * Create signal handler execution context.
+	 * Return context not modified until this point.
+	 */
+
+	/* Set up registers for signal handler; preserve the threadptr */
+	tp = regs->threadptr;
+	ps = regs->ps;
+	start_thread(regs, (unsigned long) ksig->ka.sa.sa_handler,
+		     (unsigned long) frame);
+
+	/* Set up a stack frame for a call4 if userspace uses windowed ABI */
+	if (ps & PS_WOE_MASK) {
+		base = 4;
+		regs->areg[base] =
+			(((unsigned long) ra) & 0x3fffffff) | 0x40000000;
+		ps = (ps & ~(PS_CALLINC_MASK | PS_OWB_MASK)) |
+			(1 << PS_CALLINC_SHIFT);
+	} else {
+		base = 0;
+		regs->areg[base] = (unsigned long) ra;
+	}
+	regs->areg[base + 2] = (unsigned long) sig;
+	regs->areg[base + 3] = (unsigned long) &frame->info;
+	regs->areg[base + 4] = (unsigned long) &frame->uc;
+	regs->threadptr = tp;
+	regs->ps = ps;
+
+	pr_debug("SIG rt deliver (%s:%d): signal=%d sp=%p pc=%08lx\n",
+		 current->comm, current->pid, sig, frame, regs->pc);
+
+	return 0;
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ *
+ * Note that we go through the signals twice: once to check the signals that
+ * the kernel can handle, and then we build all the user-level signal handling
+ * stack-frames in one go after that.
+ */
+static void do_signal(struct pt_regs *regs)
+{
+	struct ksignal ksig;
+
+	task_pt_regs(current)->icountlevel = 0;
+
+	if (get_signal(&ksig)) {
+		int ret;
+
+		/* Are we from a system call? */
+
+		if (regs->syscall != NO_SYSCALL) {
+
+			/* If so, check system call restarting.. */
+
+			switch (regs->areg[2]) {
+				case -ERESTARTNOHAND:
+				case -ERESTART_RESTARTBLOCK:
+					regs->areg[2] = -EINTR;
+					break;
+
+				case -ERESTARTSYS:
+					if (!(ksig.ka.sa.sa_flags & SA_RESTART)) {
+						regs->areg[2] = -EINTR;
+						break;
+					}
+					fallthrough;
+				case -ERESTARTNOINTR:
+					regs->areg[2] = regs->syscall;
+					regs->pc -= 3;
+					break;
+
+				default:
+					/* nothing to do */
+					if (regs->areg[2] != 0)
+					break;
+			}
+		}
+
+		/* Whee!  Actually deliver the signal.  */
+		/* Set up the stack frame */
+		ret = setup_frame(&ksig, sigmask_to_save(), regs);
+		signal_setup_done(ret, &ksig, 0);
+		if (test_thread_flag(TIF_SINGLESTEP))
+			task_pt_regs(current)->icountlevel = 1;
+
+		return;
+	}
+
+	/* Did we come from a system call? */
+	if (regs->syscall != NO_SYSCALL) {
+		/* Restart the system call - no handlers present */
+		switch (regs->areg[2]) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			regs->areg[2] = regs->syscall;
+			regs->pc -= 3;
+			break;
+		case -ERESTART_RESTARTBLOCK:
+			regs->areg[2] = __NR_restart_syscall;
+			regs->pc -= 3;
+			break;
+		}
+	}
+
+	/* If there's no signal to deliver, we just restore the saved mask.  */
+	restore_saved_sigmask();
+
+	if (test_thread_flag(TIF_SINGLESTEP))
+		task_pt_regs(current)->icountlevel = 1;
+	return;
+}
+
+void do_notify_resume(struct pt_regs *regs)
+{
+	if (test_thread_flag(TIF_SIGPENDING) ||
+	    test_thread_flag(TIF_NOTIFY_SIGNAL))
+		do_signal(regs);
+
+	if (test_thread_flag(TIF_NOTIFY_RESUME))
+		resume_user_mode_work(regs);
+}