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, 589 insertions, 0 deletions

diff --git a/arch/parisc/kernel/signal.c b/arch/parisc/kernel/signal.c
new file mode 100644
index 000000000..8bc0ddaa6
--- /dev/null
+++ b/arch/parisc/kernel/signal.c
@@ -0,0 +1,589 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  PA-RISC architecture-specific signal handling support.
+ *
+ *  Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
+ *  Copyright (C) 2000 Linuxcare, Inc.
+ *  Copyright (C) 2000-2022 Helge Deller <deller@gmx.de>
+ *  Copyright (C) 2022 John David Anglin <dave.anglin@bell.net>
+ *
+ *  Based on the ia64, i386, and alpha versions.
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/resume_user_mode.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/compat.h>
+#include <linux/elf.h>
+#include <asm/ucontext.h>
+#include <asm/rt_sigframe.h>
+#include <linux/uaccess.h>
+#include <asm/cacheflush.h>
+#include <asm/asm-offsets.h>
+#include <asm/vdso.h>
+
+#ifdef CONFIG_COMPAT
+#include "signal32.h"
+#endif
+
+#define DEBUG_SIG 0 
+#define DEBUG_SIG_LEVEL 2
+
+#if DEBUG_SIG
+#define DBG(LEVEL, ...) \
+        ((DEBUG_SIG_LEVEL >= LEVEL) \
+	? printk(__VA_ARGS__) : (void) 0)
+#else
+#define DBG(LEVEL, ...)
+#endif
+	
+/* gcc will complain if a pointer is cast to an integer of different
+ * size.  If you really need to do this (and we do for an ELF32 user
+ * application in an ELF64 kernel) then you have to do a cast to an
+ * integer of the same size first.  The A() macro accomplishes
+ * this. */
+#define A(__x)	((unsigned long)(__x))
+
+/*
+ * Do a signal return - restore sigcontext.
+ */
+
+static long
+restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
+{
+	long err = 0;
+
+	err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
+	err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
+	err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
+	err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
+	err |= __get_user(regs->sar, &sc->sc_sar);
+	DBG(2, "%s: iaoq is %#lx / %#lx\n",
+			__func__, regs->iaoq[0], regs->iaoq[1]);
+	DBG(2, "%s: r28 is %ld\n", __func__, regs->gr[28]);
+	return err;
+}
+
+void
+sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
+{
+	struct rt_sigframe __user *frame;
+	sigset_t set;
+	unsigned long usp = (regs->gr[30] & ~(0x01UL));
+	unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
+#ifdef CONFIG_64BIT
+	struct compat_rt_sigframe __user * compat_frame;
+	
+	if (is_compat_task())
+		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
+#endif
+
+	current->restart_block.fn = do_no_restart_syscall;
+
+	/* Unwind the user stack to get the rt_sigframe structure. */
+	frame = (struct rt_sigframe __user *)
+		(usp - sigframe_size);
+	DBG(2, "%s: frame is %p pid %d\n", __func__, frame, task_pid_nr(current));
+
+	regs->orig_r28 = 1; /* no restarts for sigreturn */
+
+#ifdef CONFIG_64BIT
+	compat_frame = (struct compat_rt_sigframe __user *)frame;
+	
+	if (is_compat_task()) {
+		if (get_compat_sigset(&set, &compat_frame->uc.uc_sigmask))
+			goto give_sigsegv;
+	} else
+#endif
+	{
+		if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+			goto give_sigsegv;
+	}
+		
+	set_current_blocked(&set);
+
+	/* Good thing we saved the old gr[30], eh? */
+#ifdef CONFIG_64BIT
+	if (is_compat_task()) {
+		DBG(1, "%s: compat_frame->uc.uc_mcontext 0x%p\n",
+				__func__, &compat_frame->uc.uc_mcontext);
+// FIXME: Load upper half from register file
+		if (restore_sigcontext32(&compat_frame->uc.uc_mcontext, 
+					&compat_frame->regs, regs))
+			goto give_sigsegv;
+		DBG(1, "%s: usp %#08lx stack 0x%p\n",
+				__func__, usp, &compat_frame->uc.uc_stack);
+		if (compat_restore_altstack(&compat_frame->uc.uc_stack))
+			goto give_sigsegv;
+	} else
+#endif
+	{
+		DBG(1, "%s: frame->uc.uc_mcontext 0x%p\n",
+				__func__, &frame->uc.uc_mcontext);
+		if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
+			goto give_sigsegv;
+		DBG(1, "%s: usp %#08lx stack 0x%p\n",
+				__func__, usp, &frame->uc.uc_stack);
+		if (restore_altstack(&frame->uc.uc_stack))
+			goto give_sigsegv;
+	}
+		
+
+
+	/* If we are on the syscall path IAOQ will not be restored, and
+	 * if we are on the interrupt path we must not corrupt gr31.
+	 */
+	if (in_syscall)
+		regs->gr[31] = regs->iaoq[0];
+
+	return;
+
+give_sigsegv:
+	DBG(1, "%s: Sending SIGSEGV\n", __func__);
+	force_sig(SIGSEGV);
+	return;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
+{
+	/*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
+	  don't use the parameter it doesn't matter */
+
+	DBG(1, "%s: ka = %#lx, sp = %#lx, frame_size = %zu\n",
+			__func__, (unsigned long)ka, sp, frame_size);
+	
+	/* Align alternate stack and reserve 64 bytes for the signal
+	   handler's frame marker.  */
+	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
+		sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */
+
+	DBG(1, "%s: Returning sp = %#lx\n", __func__, (unsigned long)sp);
+	return (void __user *) sp; /* Stacks grow up.  Fun. */
+}
+
+static long
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
+		 
+{
+	unsigned long flags = 0;
+	long err = 0;
+
+	if (on_sig_stack((unsigned long) sc))
+		flags |= PARISC_SC_FLAG_ONSTACK;
+	if (in_syscall) {
+		flags |= PARISC_SC_FLAG_IN_SYSCALL;
+		/* regs->iaoq is undefined in the syscall return path */
+		err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
+		err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
+		err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
+		err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
+		DBG(1, "%s: iaoq %#lx / %#lx (in syscall)\n",
+			__func__, regs->gr[31], regs->gr[31]+4);
+	} else {
+		err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
+		err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
+		DBG(1, "%s: iaoq %#lx / %#lx (not in syscall)\n",
+			__func__, regs->iaoq[0], regs->iaoq[1]);
+	}
+
+	err |= __put_user(flags, &sc->sc_flags);
+	err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
+	err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
+	err |= __put_user(regs->sar, &sc->sc_sar);
+	DBG(1, "%s: r28 is %ld\n", __func__, regs->gr[28]);
+
+	return err;
+}
+
+static long
+setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
+	       int in_syscall)
+{
+	struct rt_sigframe __user *frame;
+	unsigned long rp, usp;
+	unsigned long haddr, sigframe_size;
+	unsigned long start;
+	int err = 0;
+#ifdef CONFIG_64BIT
+	struct compat_rt_sigframe __user * compat_frame;
+#endif
+	
+	usp = (regs->gr[30] & ~(0x01UL));
+	sigframe_size = PARISC_RT_SIGFRAME_SIZE;
+#ifdef CONFIG_64BIT
+	if (is_compat_task()) {
+		/* The gcc alloca implementation leaves garbage in the upper 32 bits of sp */
+		usp = (compat_uint_t)usp;
+		sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
+	}
+#endif
+	frame = get_sigframe(&ksig->ka, usp, sigframe_size);
+
+	DBG(1, "%s: frame %p info %p\n", __func__, frame, &ksig->info);
+
+	start = (unsigned long) frame;
+	if (start >= TASK_SIZE_MAX - sigframe_size)
+		return -EFAULT;
+	
+#ifdef CONFIG_64BIT
+
+	compat_frame = (struct compat_rt_sigframe __user *)frame;
+	
+	if (is_compat_task()) {
+		DBG(1, "%s: frame->info = 0x%p\n", __func__, &compat_frame->info);
+		err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info);
+		err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]);
+		DBG(1, "%s: frame->uc = 0x%p\n", __func__, &compat_frame->uc);
+		DBG(1, "%s: frame->uc.uc_mcontext = 0x%p\n",
+			__func__, &compat_frame->uc.uc_mcontext);
+		err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext, 
+					&compat_frame->regs, regs, in_syscall);
+		err |= put_compat_sigset(&compat_frame->uc.uc_sigmask, set,
+					 sizeof(compat_sigset_t));
+	} else
+#endif
+	{	
+		DBG(1, "%s: frame->info = 0x%p\n", __func__, &frame->info);
+		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+		err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]);
+		DBG(1, "%s: frame->uc = 0x%p\n", __func__, &frame->uc);
+		DBG(1, "%s: frame->uc.uc_mcontext = 0x%p\n",
+			__func__, &frame->uc.uc_mcontext);
+		err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
+		/* FIXME: Should probably be converted as well for the compat case */
+		err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+	}
+	
+	if (err)
+		return -EFAULT;
+
+#ifdef CONFIG_64BIT
+	if (!is_compat_task())
+		rp = VDSO64_SYMBOL(current, sigtramp_rt);
+	else
+#endif
+		rp = VDSO32_SYMBOL(current, sigtramp_rt);
+
+	if (in_syscall)
+		rp += 4*4; /* skip 4 instructions and start at ldi 1,%r25 */
+
+	haddr = A(ksig->ka.sa.sa_handler);
+	/* The sa_handler may be a pointer to a function descriptor */
+#ifdef CONFIG_64BIT
+	if (is_compat_task()) {
+#endif
+		if (haddr & PA_PLABEL_FDESC) {
+			Elf32_Fdesc fdesc;
+			Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
+
+			err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
+
+			if (err)
+				return -EFAULT;
+
+			haddr = fdesc.addr;
+			regs->gr[19] = fdesc.gp;
+		}
+#ifdef CONFIG_64BIT
+	} else {
+		Elf64_Fdesc fdesc;
+		Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
+		
+		err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
+		
+		if (err)
+			return -EFAULT;
+		
+		haddr = fdesc.addr;
+		regs->gr[19] = fdesc.gp;
+		DBG(1, "%s: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
+		     __func__, haddr, regs->gr[19], in_syscall);
+	}
+#endif
+
+	/* The syscall return path will create IAOQ values from r31.
+	 */
+	if (in_syscall) {
+		regs->gr[31] = haddr;
+#ifdef CONFIG_64BIT
+		if (!test_thread_flag(TIF_32BIT))
+			sigframe_size |= 1; /* XXX ???? */
+#endif
+	} else {
+		unsigned long psw = USER_PSW;
+#ifdef CONFIG_64BIT
+		if (!test_thread_flag(TIF_32BIT))
+			psw |= PSW_W;
+#endif
+
+		/* If we are singlestepping, arrange a trap to be delivered
+		   when we return to userspace. Note the semantics -- we
+		   should trap before the first insn in the handler is
+		   executed. Ref:
+			http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
+		 */
+		if (pa_psw(current)->r) {
+			pa_psw(current)->r = 0;
+			psw |= PSW_R;
+			mtctl(-1, 0);
+		}
+
+		regs->gr[0] = psw;
+		regs->iaoq[0] = haddr | PRIV_USER;
+		regs->iaoq[1] = regs->iaoq[0] + 4;
+	}
+
+	regs->gr[2]  = rp;			/* userland return pointer */
+	regs->gr[26] = ksig->sig;               /* signal number */
+	
+#ifdef CONFIG_64BIT
+	if (is_compat_task()) {
+		regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
+		regs->gr[24] = A(&compat_frame->uc);   /* ucontext pointer */
+	} else
+#endif
+	{		
+		regs->gr[25] = A(&frame->info); /* siginfo pointer */
+		regs->gr[24] = A(&frame->uc);   /* ucontext pointer */
+	}
+	
+	DBG(1, "%s: making sigreturn frame: %#lx + %#lx = %#lx\n", __func__,
+	       regs->gr[30], sigframe_size,
+	       regs->gr[30] + sigframe_size);
+	/* Raise the user stack pointer to make a proper call frame. */
+	regs->gr[30] = (A(frame) + sigframe_size);
+
+
+	DBG(1, "%s: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
+	       __func__, current->comm, current->pid, frame, regs->gr[30],
+	       regs->iaoq[0], regs->iaoq[1], rp);
+
+	return 0;
+}
+
+/*
+ * OK, we're invoking a handler.
+ */	
+
+static void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall)
+{
+	int ret;
+	sigset_t *oldset = sigmask_to_save();
+
+	DBG(1, "%s: sig=%d, ka=%p, info=%p, oldset=%p, regs=%p\n",
+	       __func__, ksig->sig, &ksig->ka, &ksig->info, oldset, regs);
+	
+	/* Set up the stack frame */
+	ret = setup_rt_frame(ksig, oldset, regs, in_syscall);
+
+	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) ||
+			  test_thread_flag(TIF_BLOCKSTEP));
+
+	DBG(1, "%s: Exit (success), regs->gr[28] = %ld\n",
+		__func__, regs->gr[28]);
+}
+
+/*
+ * Check how the syscall number gets loaded into %r20 within
+ * the delay branch in userspace and adjust as needed.
+ */
+
+static void check_syscallno_in_delay_branch(struct pt_regs *regs)
+{
+	u32 opcode, source_reg;
+	u32 __user *uaddr;
+	int err;
+
+	/* Usually we don't have to restore %r20 (the system call number)
+	 * because it gets loaded in the delay slot of the branch external
+	 * instruction via the ldi instruction.
+	 * In some cases a register-to-register copy instruction might have
+	 * been used instead, in which case we need to copy the syscall
+	 * number into the source register before returning to userspace.
+	 */
+
+	/* A syscall is just a branch, so all we have to do is fiddle the
+	 * return pointer so that the ble instruction gets executed again.
+	 */
+	regs->gr[31] -= 8; /* delayed branching */
+
+	/* Get assembler opcode of code in delay branch */
+	uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4);
+	err = get_user(opcode, uaddr);
+	if (err)
+		return;
+
+	/* Check if delay branch uses "ldi int,%r20" */
+	if ((opcode & 0xffff0000) == 0x34140000)
+		return;	/* everything ok, just return */
+
+	/* Check if delay branch uses "nop" */
+	if (opcode == INSN_NOP)
+		return;
+
+	/* Check if delay branch uses "copy %rX,%r20" */
+	if ((opcode & 0xffe0ffff) == 0x08000254) {
+		source_reg = (opcode >> 16) & 31;
+		regs->gr[source_reg] = regs->gr[20];
+		return;
+	}
+
+	pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n",
+		current->comm, task_pid_nr(current), opcode);
+}
+
+static inline void
+syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
+{
+	if (regs->orig_r28)
+		return;
+	regs->orig_r28 = 1; /* no more restarts */
+
+	DBG(1, "%s:  orig_r28 = %ld  pid %d  r20 %ld\n",
+		__func__, regs->orig_r28, task_pid_nr(current), regs->gr[20]);
+
+	/* Check the return code */
+	switch (regs->gr[28]) {
+	case -ERESTART_RESTARTBLOCK:
+	case -ERESTARTNOHAND:
+		DBG(1, "%s: ERESTARTNOHAND: returning -EINTR\n", __func__);
+		regs->gr[28] = -EINTR;
+		break;
+	case -ERESTARTSYS:
+		if (!(ka->sa.sa_flags & SA_RESTART)) {
+			DBG(1, "%s: ERESTARTSYS: putting -EINTR pid %d\n",
+				__func__, task_pid_nr(current));
+			regs->gr[28] = -EINTR;
+			break;
+		}
+		fallthrough;
+	case -ERESTARTNOINTR:
+		DBG(1, "%s: %ld\n", __func__, regs->gr[28]);
+		check_syscallno_in_delay_branch(regs);
+		break;
+	}
+}
+
+static inline void
+insert_restart_trampoline(struct pt_regs *regs)
+{
+	if (regs->orig_r28)
+		return;
+	regs->orig_r28 = 1; /* no more restarts */
+
+	DBG(2, "%s: gr28 = %ld pid %d\n",
+		__func__, regs->gr[28], task_pid_nr(current));
+
+	switch (regs->gr[28]) {
+	case -ERESTART_RESTARTBLOCK: {
+		/* Restart the system call - no handlers present */
+		unsigned int *usp = (unsigned int *)regs->gr[30];
+		unsigned long rp;
+		long err = 0;
+
+		/* check that we don't exceed the stack */
+		if (A(&usp[0]) >= TASK_SIZE_MAX - 5 * sizeof(int))
+			return;
+
+		/* Call trampoline in vdso to restart the syscall
+		 * with __NR_restart_syscall.
+		 * Original return addresses are on stack like this:
+		 *
+		 *  0: <return address (orig r31)>
+		 *  4: <2nd half for 64-bit>
+		 */
+#ifdef CONFIG_64BIT
+		if (!is_compat_task()) {
+			err |= put_user(regs->gr[31] >> 32, &usp[0]);
+			err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]);
+			rp = VDSO64_SYMBOL(current, restart_syscall);
+		} else
+#endif
+		{
+			err |= put_user(regs->gr[31], &usp[0]);
+			rp = VDSO32_SYMBOL(current, restart_syscall);
+		}
+		WARN_ON(err);
+
+		regs->gr[31] = rp;
+		DBG(1, "%s: ERESTART_RESTARTBLOCK\n", __func__);
+		return;
+	}
+	case -EINTR:
+		/* ok, was handled before and should be returned. */
+		break;
+	case -ERESTARTNOHAND:
+	case -ERESTARTSYS:
+	case -ERESTARTNOINTR:
+		DBG(1, "%s: Type %ld\n", __func__, regs->gr[28]);
+		check_syscallno_in_delay_branch(regs);
+		return;
+	default:
+		break;
+	}
+}
+
+/*
+ * We need to be able to restore the syscall arguments (r21-r26) to
+ * restart syscalls.  Thus, the syscall path should save them in the
+ * pt_regs structure (it's okay to do so since they are caller-save
+ * registers).  As noted below, the syscall number gets restored for
+ * us due to the magic of delayed branching.
+ */
+static void do_signal(struct pt_regs *regs, long in_syscall)
+{
+	struct ksignal ksig;
+	int restart_syscall;
+	bool has_handler;
+
+	has_handler = get_signal(&ksig);
+
+	restart_syscall = 0;
+	if (in_syscall)
+		restart_syscall = 1;
+
+	if (has_handler) {
+		/* Restart a system call if necessary. */
+		if (restart_syscall)
+			syscall_restart(regs, &ksig.ka);
+
+		handle_signal(&ksig, regs, in_syscall);
+		DBG(1, "%s: Handled signal pid %d\n",
+			__func__, task_pid_nr(current));
+		return;
+	}
+
+	/* Do we need to restart the system call? */
+	if (restart_syscall)
+		insert_restart_trampoline(regs);
+	
+	DBG(1, "%s: Exit (not delivered), regs->gr[28] = %ld  orig_r28 = %ld  pid %d\n",
+		__func__, regs->gr[28], regs->orig_r28, task_pid_nr(current));
+
+	restore_saved_sigmask();
+}
+
+void do_notify_resume(struct pt_regs *regs, long in_syscall)
+{
+	if (test_thread_flag(TIF_SIGPENDING) ||
+	    test_thread_flag(TIF_NOTIFY_SIGNAL))
+		do_signal(regs, in_syscall);
+
+	if (test_thread_flag(TIF_NOTIFY_RESUME))
+		resume_user_mode_work(regs);
+}