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, 565 insertions, 0 deletions

diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c
new file mode 100644
index 000000000..89b93c713
--- /dev/null
+++ b/arch/sparc/kernel/signal_32.c
@@ -0,0 +1,565 @@
+// SPDX-License-Identifier: GPL-2.0
+/*  linux/arch/sparc/kernel/signal.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
+ *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/mm.h>
+#include <linux/tty.h>
+#include <linux/smp.h>
+#include <linux/binfmts.h>	/* do_coredum */
+#include <linux/bitops.h>
+#include <linux/resume_user_mode.h>
+
+#include <linux/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/cacheflush.h>	/* flush_sig_insns */
+#include <asm/switch_to.h>
+
+#include "sigutil.h"
+#include "kernel.h"
+
+extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
+		   void *fpqueue, unsigned long *fpqdepth);
+extern void fpload(unsigned long *fpregs, unsigned long *fsr);
+
+struct signal_frame {
+	struct sparc_stackf	ss;
+	__siginfo32_t		info;
+	__siginfo_fpu_t __user	*fpu_save;
+	unsigned long		insns[2] __attribute__ ((aligned (8)));
+	unsigned int		extramask[_NSIG_WORDS - 1];
+	unsigned int		extra_size; /* Should be 0 */
+	__siginfo_rwin_t __user	*rwin_save;
+} __attribute__((aligned(8)));
+
+struct rt_signal_frame {
+	struct sparc_stackf	ss;
+	siginfo_t		info;
+	struct pt_regs		regs;
+	sigset_t		mask;
+	__siginfo_fpu_t __user	*fpu_save;
+	unsigned int		insns[2];
+	stack_t			stack;
+	unsigned int		extra_size; /* Should be 0 */
+	__siginfo_rwin_t __user	*rwin_save;
+} __attribute__((aligned(8)));
+
+/* Align macros */
+#define SF_ALIGNEDSZ  (((sizeof(struct signal_frame) + 7) & (~7)))
+#define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))
+
+/* Checks if the fp is valid.  We always build signal frames which are
+ * 16-byte aligned, therefore we can always enforce that the restore
+ * frame has that property as well.
+ */
+static inline bool invalid_frame_pointer(void __user *fp, int fplen)
+{
+	if ((((unsigned long) fp) & 15) || !access_ok(fp, fplen))
+		return true;
+
+	return false;
+}
+
+asmlinkage void do_sigreturn(struct pt_regs *regs)
+{
+	unsigned long up_psr, pc, npc, ufp;
+	struct signal_frame __user *sf;
+	sigset_t set;
+	__siginfo_fpu_t __user *fpu_save;
+	__siginfo_rwin_t __user *rwin_save;
+	int err;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	synchronize_user_stack();
+
+	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
+
+	/* 1. Make sure we are not getting garbage from the user */
+	if (invalid_frame_pointer(sf, sizeof(*sf)))
+		goto segv_and_exit;
+
+	if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
+		goto segv_and_exit;
+
+	if (ufp & 0x7)
+		goto segv_and_exit;
+
+	err = __get_user(pc,  &sf->info.si_regs.pc);
+	err |= __get_user(npc, &sf->info.si_regs.npc);
+
+	if ((pc | npc) & 3)
+		goto segv_and_exit;
+
+	/* 2. Restore the state */
+	up_psr = regs->psr;
+	err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
+
+	/* User can only change condition codes and FPU enabling in %psr. */
+	regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
+		  | (regs->psr & (PSR_ICC | PSR_EF));
+
+	/* Prevent syscall restart.  */
+	pt_regs_clear_syscall(regs);
+
+	err |= __get_user(fpu_save, &sf->fpu_save);
+	if (fpu_save)
+		err |= restore_fpu_state(regs, fpu_save);
+	err |= __get_user(rwin_save, &sf->rwin_save);
+	if (rwin_save)
+		err |= restore_rwin_state(rwin_save);
+
+	/* This is pretty much atomic, no amount locking would prevent
+	 * the races which exist anyways.
+	 */
+	err |= __get_user(set.sig[0], &sf->info.si_mask);
+	err |= __copy_from_user(&set.sig[1], &sf->extramask,
+			        (_NSIG_WORDS-1) * sizeof(unsigned int));
+			   
+	if (err)
+		goto segv_and_exit;
+
+	set_current_blocked(&set);
+	return;
+
+segv_and_exit:
+	force_sig(SIGSEGV);
+}
+
+asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
+{
+	struct rt_signal_frame __user *sf;
+	unsigned int psr, pc, npc, ufp;
+	__siginfo_fpu_t __user *fpu_save;
+	__siginfo_rwin_t __user *rwin_save;
+	sigset_t set;
+	int err;
+
+	synchronize_user_stack();
+	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
+	if (invalid_frame_pointer(sf, sizeof(*sf)))
+		goto segv;
+
+	if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
+		goto segv;
+
+	if (ufp & 0x7)
+		goto segv;
+
+	err = __get_user(pc, &sf->regs.pc);
+	err |= __get_user(npc, &sf->regs.npc);
+	err |= ((pc | npc) & 0x03);
+
+	err |= __get_user(regs->y, &sf->regs.y);
+	err |= __get_user(psr, &sf->regs.psr);
+
+	err |= __copy_from_user(&regs->u_regs[UREG_G1],
+				&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
+
+	regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);
+
+	/* Prevent syscall restart.  */
+	pt_regs_clear_syscall(regs);
+
+	err |= __get_user(fpu_save, &sf->fpu_save);
+	if (!err && fpu_save)
+		err |= restore_fpu_state(regs, fpu_save);
+	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
+	err |= restore_altstack(&sf->stack);
+	
+	if (err)
+		goto segv;
+		
+	regs->pc = pc;
+	regs->npc = npc;
+	
+	err |= __get_user(rwin_save, &sf->rwin_save);
+	if (!err && rwin_save) {
+		if (restore_rwin_state(rwin_save))
+			goto segv;
+	}
+
+	set_current_blocked(&set);
+	return;
+segv:
+	force_sig(SIGSEGV);
+}
+
+static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
+{
+	unsigned long sp = regs->u_regs[UREG_FP];
+
+	/*
+	 * If we are on the alternate signal stack and would overflow it, don't.
+	 * Return an always-bogus address instead so we will die with SIGSEGV.
+	 */
+	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
+		return (void __user *) -1L;
+
+	/* This is the X/Open sanctioned signal stack switching.  */
+	sp = sigsp(sp, ksig) - framesize;
+
+	/* Always align the stack frame.  This handles two cases.  First,
+	 * sigaltstack need not be mindful of platform specific stack
+	 * alignment.  Second, if we took this signal because the stack
+	 * is not aligned properly, we'd like to take the signal cleanly
+	 * and report that.
+	 */
+	sp &= ~15UL;
+
+	return (void __user *) sp;
+}
+
+static int setup_frame(struct ksignal *ksig, struct pt_regs *regs,
+		       sigset_t *oldset)
+{
+	struct signal_frame __user *sf;
+	int sigframe_size, err, wsaved;
+	void __user *tail;
+
+	/* 1. Make sure everything is clean */
+	synchronize_user_stack();
+
+	wsaved = current_thread_info()->w_saved;
+
+	sigframe_size = sizeof(*sf);
+	if (used_math())
+		sigframe_size += sizeof(__siginfo_fpu_t);
+	if (wsaved)
+		sigframe_size += sizeof(__siginfo_rwin_t);
+
+	sf = (struct signal_frame __user *)
+		get_sigframe(ksig, regs, sigframe_size);
+
+	if (invalid_frame_pointer(sf, sigframe_size)) {
+		force_exit_sig(SIGILL);
+		return -EINVAL;
+	}
+
+	tail = sf + 1;
+
+	/* 2. Save the current process state */
+	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
+	
+	err |= __put_user(0, &sf->extra_size);
+
+	if (used_math()) {
+		__siginfo_fpu_t __user *fp = tail;
+		tail += sizeof(*fp);
+		err |= save_fpu_state(regs, fp);
+		err |= __put_user(fp, &sf->fpu_save);
+	} else {
+		err |= __put_user(0, &sf->fpu_save);
+	}
+	if (wsaved) {
+		__siginfo_rwin_t __user *rwp = tail;
+		tail += sizeof(*rwp);
+		err |= save_rwin_state(wsaved, rwp);
+		err |= __put_user(rwp, &sf->rwin_save);
+	} else {
+		err |= __put_user(0, &sf->rwin_save);
+	}
+
+	err |= __put_user(oldset->sig[0], &sf->info.si_mask);
+	err |= __copy_to_user(sf->extramask, &oldset->sig[1],
+			      (_NSIG_WORDS - 1) * sizeof(unsigned int));
+	if (!wsaved) {
+		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
+				      sizeof(struct reg_window32));
+	} else {
+		struct reg_window32 *rp;
+
+		rp = &current_thread_info()->reg_window[wsaved - 1];
+		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
+	}
+	if (err)
+		return err;
+	
+	/* 3. signal handler back-trampoline and parameters */
+	regs->u_regs[UREG_FP] = (unsigned long) sf;
+	regs->u_regs[UREG_I0] = ksig->sig;
+	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
+	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
+
+	/* 4. signal handler */
+	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+	regs->npc = (regs->pc + 4);
+
+	/* 5. return to kernel instructions */
+	if (ksig->ka.ka_restorer)
+		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
+	else {
+		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
+
+		/* mov __NR_sigreturn, %g1 */
+		err |= __put_user(0x821020d8, &sf->insns[0]);
+
+		/* t 0x10 */
+		err |= __put_user(0x91d02010, &sf->insns[1]);
+		if (err)
+			return err;
+
+		/* Flush instruction space. */
+		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
+	}
+	return 0;
+}
+
+static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
+			  sigset_t *oldset)
+{
+	struct rt_signal_frame __user *sf;
+	int sigframe_size, wsaved;
+	void __user *tail;
+	unsigned int psr;
+	int err;
+
+	synchronize_user_stack();
+	wsaved = current_thread_info()->w_saved;
+	sigframe_size = sizeof(*sf);
+	if (used_math())
+		sigframe_size += sizeof(__siginfo_fpu_t);
+	if (wsaved)
+		sigframe_size += sizeof(__siginfo_rwin_t);
+	sf = (struct rt_signal_frame __user *)
+		get_sigframe(ksig, regs, sigframe_size);
+	if (invalid_frame_pointer(sf, sigframe_size)) {
+		force_exit_sig(SIGILL);
+		return -EINVAL;
+	}
+
+	tail = sf + 1;
+	err  = __put_user(regs->pc, &sf->regs.pc);
+	err |= __put_user(regs->npc, &sf->regs.npc);
+	err |= __put_user(regs->y, &sf->regs.y);
+	psr = regs->psr;
+	if (used_math())
+		psr |= PSR_EF;
+	err |= __put_user(psr, &sf->regs.psr);
+	err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
+	err |= __put_user(0, &sf->extra_size);
+
+	if (psr & PSR_EF) {
+		__siginfo_fpu_t __user *fp = tail;
+		tail += sizeof(*fp);
+		err |= save_fpu_state(regs, fp);
+		err |= __put_user(fp, &sf->fpu_save);
+	} else {
+		err |= __put_user(0, &sf->fpu_save);
+	}
+	if (wsaved) {
+		__siginfo_rwin_t __user *rwp = tail;
+		tail += sizeof(*rwp);
+		err |= save_rwin_state(wsaved, rwp);
+		err |= __put_user(rwp, &sf->rwin_save);
+	} else {
+		err |= __put_user(0, &sf->rwin_save);
+	}
+	err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
+	
+	/* Setup sigaltstack */
+	err |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
+	
+	if (!wsaved) {
+		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
+				      sizeof(struct reg_window32));
+	} else {
+		struct reg_window32 *rp;
+
+		rp = &current_thread_info()->reg_window[wsaved - 1];
+		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
+	}
+
+	err |= copy_siginfo_to_user(&sf->info, &ksig->info);
+
+	if (err)
+		return err;
+
+	regs->u_regs[UREG_FP] = (unsigned long) sf;
+	regs->u_regs[UREG_I0] = ksig->sig;
+	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
+	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
+
+	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
+	regs->npc = (regs->pc + 4);
+
+	if (ksig->ka.ka_restorer)
+		regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
+	else {
+		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
+
+		/* mov __NR_rt_sigreturn, %g1 */
+		err |= __put_user(0x82102065, &sf->insns[0]);
+
+		/* t 0x10 */
+		err |= __put_user(0x91d02010, &sf->insns[1]);
+		if (err)
+			return err;
+
+		/* Flush instruction space. */
+		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
+	}
+	return 0;
+}
+
+static inline void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	sigset_t *oldset = sigmask_to_save();
+	int err;
+
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		err = setup_rt_frame(ksig, regs, oldset);
+	else
+		err = setup_frame(ksig, regs, oldset);
+	signal_setup_done(err, ksig, 0);
+}
+
+static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
+				   struct sigaction *sa)
+{
+	switch(regs->u_regs[UREG_I0]) {
+	case ERESTART_RESTARTBLOCK:
+	case ERESTARTNOHAND:
+	no_system_call_restart:
+		regs->u_regs[UREG_I0] = EINTR;
+		regs->psr |= PSR_C;
+		break;
+	case ERESTARTSYS:
+		if (!(sa->sa_flags & SA_RESTART))
+			goto no_system_call_restart;
+		fallthrough;
+	case ERESTARTNOINTR:
+		regs->u_regs[UREG_I0] = orig_i0;
+		regs->pc -= 4;
+		regs->npc -= 4;
+	}
+}
+
+/* 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.
+ */
+static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
+{
+	struct ksignal ksig;
+	int restart_syscall;
+	bool has_handler;
+
+	/* It's a lot of work and synchronization to add a new ptrace
+	 * register for GDB to save and restore in order to get
+	 * orig_i0 correct for syscall restarts when debugging.
+	 *
+	 * Although it should be the case that most of the global
+	 * registers are volatile across a system call, glibc already
+	 * depends upon that fact that we preserve them.  So we can't
+	 * just use any global register to save away the orig_i0 value.
+	 *
+	 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
+	 * preserved across a system call trap by various pieces of
+	 * code in glibc.
+	 *
+	 * %g7 is used as the "thread register".   %g6 is not used in
+	 * any fixed manner.  %g6 is used as a scratch register and
+	 * a compiler temporary, but it's value is never used across
+	 * a system call.  Therefore %g6 is usable for orig_i0 storage.
+	 */
+	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
+		regs->u_regs[UREG_G6] = orig_i0;
+
+	has_handler = get_signal(&ksig);
+
+	/* If the debugger messes with the program counter, it clears
+	 * the software "in syscall" bit, directing us to not perform
+	 * a syscall restart.
+	 */
+	restart_syscall = 0;
+	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
+		restart_syscall = 1;
+		orig_i0 = regs->u_regs[UREG_G6];
+	}
+
+	if (has_handler) {
+		if (restart_syscall)
+			syscall_restart(orig_i0, regs, &ksig.ka.sa);
+		handle_signal(&ksig, regs);
+	} else {
+		if (restart_syscall) {
+			switch (regs->u_regs[UREG_I0]) {
+			case ERESTARTNOHAND:
+	     		case ERESTARTSYS:
+			case ERESTARTNOINTR:
+				/* replay the system call when we are done */
+				regs->u_regs[UREG_I0] = orig_i0;
+				regs->pc -= 4;
+				regs->npc -= 4;
+				pt_regs_clear_syscall(regs);
+				fallthrough;
+			case ERESTART_RESTARTBLOCK:
+				regs->u_regs[UREG_G1] = __NR_restart_syscall;
+				regs->pc -= 4;
+				regs->npc -= 4;
+				pt_regs_clear_syscall(regs);
+			}
+		}
+		restore_saved_sigmask();
+	}
+}
+
+void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
+		      unsigned long thread_info_flags)
+{
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
+		do_signal(regs, orig_i0);
+	if (thread_info_flags & _TIF_NOTIFY_RESUME)
+		resume_user_mode_work(regs);
+}
+
+asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
+                               struct sigstack __user *ossptr,
+                               unsigned long sp)
+{
+	int ret = -EFAULT;
+
+	/* First see if old state is wanted. */
+	if (ossptr) {
+		if (put_user(current->sas_ss_sp + current->sas_ss_size,
+			     &ossptr->the_stack) ||
+		    __put_user(on_sig_stack(sp), &ossptr->cur_status))
+			goto out;
+	}
+
+	/* Now see if we want to update the new state. */
+	if (ssptr) {
+		char *ss_sp;
+
+		if (get_user(ss_sp, &ssptr->the_stack))
+			goto out;
+		/* If the current stack was set with sigaltstack, don't
+		   swap stacks while we are on it.  */
+		ret = -EPERM;
+		if (current->sas_ss_sp && on_sig_stack(sp))
+			goto out;
+
+		/* Since we don't know the extent of the stack, and we don't
+		   track onstack-ness, but rather calculate it, we must
+		   presume a size.  Ho hum this interface is lossy.  */
+		current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
+		current->sas_ss_size = SIGSTKSZ;
+	}
+	ret = 0;
+out:
+	return ret;
+}