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, 566 insertions, 0 deletions

diff --git a/arch/loongarch/kernel/signal.c b/arch/loongarch/kernel/signal.c
new file mode 100644
index 000000000..8f5b79863
--- /dev/null
+++ b/arch/loongarch/kernel/signal.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Author: Hanlu Li <lihanlu@loongson.cn>
+ *         Huacai Chen <chenhuacai@loongson.cn>
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1991, 1992  Linus Torvalds
+ * Copyright (C) 1994 - 2000  Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2014, Imagination Technologies Ltd.
+ */
+#include <linux/audit.h>
+#include <linux/cache.h>
+#include <linux/context_tracking.h>
+#include <linux/irqflags.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/personality.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/unistd.h>
+#include <linux/compiler.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+
+#include <asm/asm.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu-features.h>
+#include <asm/fpu.h>
+#include <asm/ucontext.h>
+#include <asm/vdso.h>
+
+#ifdef DEBUG_SIG
+#  define DEBUGP(fmt, args...) printk("%s: " fmt, __func__, ##args)
+#else
+#  define DEBUGP(fmt, args...)
+#endif
+
+/* Make sure we will not lose FPU ownership */
+#define lock_fpu_owner()	({ preempt_disable(); pagefault_disable(); })
+#define unlock_fpu_owner()	({ pagefault_enable(); preempt_enable(); })
+
+/* Assembly functions to move context to/from the FPU */
+extern asmlinkage int
+_save_fp_context(void __user *fpregs, void __user *fcc, void __user *csr);
+extern asmlinkage int
+_restore_fp_context(void __user *fpregs, void __user *fcc, void __user *csr);
+
+struct rt_sigframe {
+	struct siginfo rs_info;
+	struct ucontext rs_uctx;
+};
+
+struct _ctx_layout {
+	struct sctx_info *addr;
+	unsigned int size;
+};
+
+struct extctx_layout {
+	unsigned long size;
+	unsigned int flags;
+	struct _ctx_layout fpu;
+	struct _ctx_layout end;
+};
+
+static void __user *get_ctx_through_ctxinfo(struct sctx_info *info)
+{
+	return (void __user *)((char *)info + sizeof(struct sctx_info));
+}
+
+/*
+ * Thread saved context copy to/from a signal context presumed to be on the
+ * user stack, and therefore accessed with appropriate macros from uaccess.h.
+ */
+static int copy_fpu_to_sigcontext(struct fpu_context __user *ctx)
+{
+	int i;
+	int err = 0;
+	uint64_t __user *regs	= (uint64_t *)&ctx->regs;
+	uint64_t __user *fcc	= &ctx->fcc;
+	uint32_t __user *fcsr	= &ctx->fcsr;
+
+	for (i = 0; i < NUM_FPU_REGS; i++) {
+		err |=
+		    __put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
+			       &regs[i]);
+	}
+	err |= __put_user(current->thread.fpu.fcc, fcc);
+	err |= __put_user(current->thread.fpu.fcsr, fcsr);
+
+	return err;
+}
+
+static int copy_fpu_from_sigcontext(struct fpu_context __user *ctx)
+{
+	int i;
+	int err = 0;
+	u64 fpr_val;
+	uint64_t __user *regs	= (uint64_t *)&ctx->regs;
+	uint64_t __user *fcc	= &ctx->fcc;
+	uint32_t __user *fcsr	= &ctx->fcsr;
+
+	for (i = 0; i < NUM_FPU_REGS; i++) {
+		err |= __get_user(fpr_val, &regs[i]);
+		set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
+	}
+	err |= __get_user(current->thread.fpu.fcc, fcc);
+	err |= __get_user(current->thread.fpu.fcsr, fcsr);
+
+	return err;
+}
+
+/*
+ * Wrappers for the assembly _{save,restore}_fp_context functions.
+ */
+static int save_hw_fpu_context(struct fpu_context __user *ctx)
+{
+	uint64_t __user *regs	= (uint64_t *)&ctx->regs;
+	uint64_t __user *fcc	= &ctx->fcc;
+	uint32_t __user *fcsr	= &ctx->fcsr;
+
+	return _save_fp_context(regs, fcc, fcsr);
+}
+
+static int restore_hw_fpu_context(struct fpu_context __user *ctx)
+{
+	uint64_t __user *regs	= (uint64_t *)&ctx->regs;
+	uint64_t __user *fcc	= &ctx->fcc;
+	uint32_t __user *fcsr	= &ctx->fcsr;
+
+	return _restore_fp_context(regs, fcc, fcsr);
+}
+
+static int fcsr_pending(unsigned int __user *fcsr)
+{
+	int err, sig = 0;
+	unsigned int csr, enabled;
+
+	err = __get_user(csr, fcsr);
+	enabled = ((csr & FPU_CSR_ALL_E) << 24);
+	/*
+	 * If the signal handler set some FPU exceptions, clear it and
+	 * send SIGFPE.
+	 */
+	if (csr & enabled) {
+		csr &= ~enabled;
+		err |= __put_user(csr, fcsr);
+		sig = SIGFPE;
+	}
+	return err ?: sig;
+}
+
+/*
+ * Helper routines
+ */
+static int protected_save_fpu_context(struct extctx_layout *extctx)
+{
+	int err = 0;
+	struct sctx_info __user *info = extctx->fpu.addr;
+	struct fpu_context __user *fpu_ctx = (struct fpu_context *)get_ctx_through_ctxinfo(info);
+	uint64_t __user *regs	= (uint64_t *)&fpu_ctx->regs;
+	uint64_t __user *fcc	= &fpu_ctx->fcc;
+	uint32_t __user *fcsr	= &fpu_ctx->fcsr;
+
+	while (1) {
+		lock_fpu_owner();
+		if (is_fpu_owner())
+			err = save_hw_fpu_context(fpu_ctx);
+		else
+			err = copy_fpu_to_sigcontext(fpu_ctx);
+		unlock_fpu_owner();
+
+		err |= __put_user(FPU_CTX_MAGIC, &info->magic);
+		err |= __put_user(extctx->fpu.size, &info->size);
+
+		if (likely(!err))
+			break;
+		/* Touch the FPU context and try again */
+		err = __put_user(0, &regs[0]) |
+			__put_user(0, &regs[31]) |
+			__put_user(0, fcc) |
+			__put_user(0, fcsr);
+		if (err)
+			return err;	/* really bad sigcontext */
+	}
+
+	return err;
+}
+
+static int protected_restore_fpu_context(struct extctx_layout *extctx)
+{
+	int err = 0, sig = 0, tmp __maybe_unused;
+	struct sctx_info __user *info = extctx->fpu.addr;
+	struct fpu_context __user *fpu_ctx = (struct fpu_context *)get_ctx_through_ctxinfo(info);
+	uint64_t __user *regs	= (uint64_t *)&fpu_ctx->regs;
+	uint64_t __user *fcc	= &fpu_ctx->fcc;
+	uint32_t __user *fcsr	= &fpu_ctx->fcsr;
+
+	err = sig = fcsr_pending(fcsr);
+	if (err < 0)
+		return err;
+
+	while (1) {
+		lock_fpu_owner();
+		if (is_fpu_owner())
+			err = restore_hw_fpu_context(fpu_ctx);
+		else
+			err = copy_fpu_from_sigcontext(fpu_ctx);
+		unlock_fpu_owner();
+
+		if (likely(!err))
+			break;
+		/* Touch the FPU context and try again */
+		err = __get_user(tmp, &regs[0]) |
+			__get_user(tmp, &regs[31]) |
+			__get_user(tmp, fcc) |
+			__get_user(tmp, fcsr);
+		if (err)
+			break;	/* really bad sigcontext */
+	}
+
+	return err ?: sig;
+}
+
+static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
+			    struct extctx_layout *extctx)
+{
+	int i, err = 0;
+	struct sctx_info __user *info;
+
+	err |= __put_user(regs->csr_era, &sc->sc_pc);
+	err |= __put_user(extctx->flags, &sc->sc_flags);
+
+	err |= __put_user(0, &sc->sc_regs[0]);
+	for (i = 1; i < 32; i++)
+		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
+
+	if (extctx->fpu.addr)
+		err |= protected_save_fpu_context(extctx);
+
+	/* Set the "end" magic */
+	info = (struct sctx_info *)extctx->end.addr;
+	err |= __put_user(0, &info->magic);
+	err |= __put_user(0, &info->size);
+
+	return err;
+}
+
+static int parse_extcontext(struct sigcontext __user *sc, struct extctx_layout *extctx)
+{
+	int err = 0;
+	unsigned int magic, size;
+	struct sctx_info __user *info = (struct sctx_info __user *)&sc->sc_extcontext;
+
+	while(1) {
+		err |= __get_user(magic, &info->magic);
+		err |= __get_user(size, &info->size);
+		if (err)
+			return err;
+
+		switch (magic) {
+		case 0: /* END */
+			goto done;
+
+		case FPU_CTX_MAGIC:
+			if (size < (sizeof(struct sctx_info) +
+				    sizeof(struct fpu_context)))
+				goto invalid;
+			extctx->fpu.addr = info;
+			break;
+
+		default:
+			goto invalid;
+		}
+
+		info = (struct sctx_info *)((char *)info + size);
+	}
+
+done:
+	return 0;
+
+invalid:
+	return -EINVAL;
+}
+
+static int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	int i, err = 0;
+	struct extctx_layout extctx;
+
+	memset(&extctx, 0, sizeof(struct extctx_layout));
+
+	err = __get_user(extctx.flags, &sc->sc_flags);
+	if (err)
+		goto bad;
+
+	err = parse_extcontext(sc, &extctx);
+	if (err)
+		goto bad;
+
+	conditional_used_math(extctx.flags & SC_USED_FP);
+
+	/*
+	 * The signal handler may have used FPU; give it up if the program
+	 * doesn't want it following sigreturn.
+	 */
+	if (!(extctx.flags & SC_USED_FP))
+		lose_fpu(0);
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	err |= __get_user(regs->csr_era, &sc->sc_pc);
+	for (i = 1; i < 32; i++)
+		err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
+
+	if (extctx.fpu.addr)
+		err |= protected_restore_fpu_context(&extctx);
+
+bad:
+	return err;
+}
+
+static unsigned int handle_flags(void)
+{
+	unsigned int flags = 0;
+
+	flags = used_math() ? SC_USED_FP : 0;
+
+	switch (current->thread.error_code) {
+	case 1:
+		flags |= SC_ADDRERR_RD;
+		break;
+	case 2:
+		flags |= SC_ADDRERR_WR;
+		break;
+	}
+
+	return flags;
+}
+
+static unsigned long extframe_alloc(struct extctx_layout *extctx,
+				    struct _ctx_layout *layout,
+				    size_t size, unsigned int align, unsigned long base)
+{
+	unsigned long new_base = base - size;
+
+	new_base = round_down(new_base, (align < 16 ? 16 : align));
+	new_base -= sizeof(struct sctx_info);
+
+	layout->addr = (void *)new_base;
+	layout->size = (unsigned int)(base - new_base);
+	extctx->size += layout->size;
+
+	return new_base;
+}
+
+static unsigned long setup_extcontext(struct extctx_layout *extctx, unsigned long sp)
+{
+	unsigned long new_sp = sp;
+
+	memset(extctx, 0, sizeof(struct extctx_layout));
+
+	extctx->flags = handle_flags();
+
+	/* Grow down, alloc "end" context info first. */
+	new_sp -= sizeof(struct sctx_info);
+	extctx->end.addr = (void *)new_sp;
+	extctx->end.size = (unsigned int)sizeof(struct sctx_info);
+	extctx->size += extctx->end.size;
+
+	if (extctx->flags & SC_USED_FP) {
+		if (cpu_has_fpu)
+			new_sp = extframe_alloc(extctx, &extctx->fpu,
+			  sizeof(struct fpu_context), FPU_CTX_ALIGN, new_sp);
+	}
+
+	return new_sp;
+}
+
+void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
+			  struct extctx_layout *extctx)
+{
+	unsigned long sp;
+
+	/* Default to using normal stack */
+	sp = regs->regs[3];
+
+	/*
+	 * 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 - sizeof(struct rt_sigframe))))
+		return (void __user __force *)(-1UL);
+
+	sp = sigsp(sp, ksig);
+	sp = round_down(sp, 16);
+	sp = setup_extcontext(extctx, sp);
+	sp -= sizeof(struct rt_sigframe);
+
+	if (!IS_ALIGNED(sp, 16))
+		BUG();
+
+	return (void __user *)sp;
+}
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+
+asmlinkage long sys_rt_sigreturn(void)
+{
+	int sig;
+	sigset_t set;
+	struct pt_regs *regs;
+	struct rt_sigframe __user *frame;
+
+	regs = current_pt_regs();
+	frame = (struct rt_sigframe __user *)regs->regs[3];
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&set, &frame->rs_uctx.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	sig = restore_sigcontext(regs, &frame->rs_uctx.uc_mcontext);
+	if (sig < 0)
+		goto badframe;
+	else if (sig)
+		force_sig(sig);
+
+	regs->regs[0] = 0; /* No syscall restarting */
+	if (restore_altstack(&frame->rs_uctx.uc_stack))
+		goto badframe;
+
+	return regs->regs[4];
+
+badframe:
+	force_sig(SIGSEGV);
+	return 0;
+}
+
+static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
+			  struct pt_regs *regs, sigset_t *set)
+{
+	int err = 0;
+	struct extctx_layout extctx;
+	struct rt_sigframe __user *frame;
+
+	frame = get_sigframe(ksig, regs, &extctx);
+	if (!access_ok(frame, sizeof(*frame) + extctx.size))
+		return -EFAULT;
+
+	/* Create siginfo.  */
+	err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
+
+	/* Create the ucontext.	 */
+	err |= __put_user(0, &frame->rs_uctx.uc_flags);
+	err |= __put_user(NULL, &frame->rs_uctx.uc_link);
+	err |= __save_altstack(&frame->rs_uctx.uc_stack, regs->regs[3]);
+	err |= setup_sigcontext(regs, &frame->rs_uctx.uc_mcontext, &extctx);
+	err |= __copy_to_user(&frame->rs_uctx.uc_sigmask, set, sizeof(*set));
+
+	if (err)
+		return -EFAULT;
+
+	/*
+	 * Arguments to signal handler:
+	 *
+	 *   a0 = signal number
+	 *   a1 = pointer to siginfo
+	 *   a2 = pointer to ucontext
+	 *
+	 * c0_era point to the signal handler, $r3 (sp) points to
+	 * the struct rt_sigframe.
+	 */
+	regs->regs[4] = ksig->sig;
+	regs->regs[5] = (unsigned long) &frame->rs_info;
+	regs->regs[6] = (unsigned long) &frame->rs_uctx;
+	regs->regs[3] = (unsigned long) frame;
+	regs->regs[1] = (unsigned long) sig_return;
+	regs->csr_era = (unsigned long) ksig->ka.sa.sa_handler;
+
+	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
+	       current->comm, current->pid,
+	       frame, regs->csr_era, regs->regs[1]);
+
+	return 0;
+}
+
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	int ret;
+	sigset_t *oldset = sigmask_to_save();
+	void *vdso = current->mm->context.vdso;
+
+	/* Are we from a system call? */
+	if (regs->regs[0]) {
+		switch (regs->regs[4]) {
+		case -ERESTART_RESTARTBLOCK:
+		case -ERESTARTNOHAND:
+			regs->regs[4] = -EINTR;
+			break;
+		case -ERESTARTSYS:
+			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+				regs->regs[4] = -EINTR;
+				break;
+			}
+			fallthrough;
+		case -ERESTARTNOINTR:
+			regs->regs[4] = regs->orig_a0;
+			regs->csr_era -= 4;
+		}
+
+		regs->regs[0] = 0;	/* Don't deal with this again.	*/
+	}
+
+	rseq_signal_deliver(ksig, regs);
+
+	ret = setup_rt_frame(vdso + current->thread.vdso->offset_sigreturn, ksig, regs, oldset);
+
+	signal_setup_done(ret, ksig, 0);
+}
+
+void arch_do_signal_or_restart(struct pt_regs *regs)
+{
+	struct ksignal ksig;
+
+	if (get_signal(&ksig)) {
+		/* Whee!  Actually deliver the signal.	*/
+		handle_signal(&ksig, regs);
+		return;
+	}
+
+	/* Are we from a system call? */
+	if (regs->regs[0]) {
+		switch (regs->regs[4]) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			regs->regs[4] = regs->orig_a0;
+			regs->csr_era -= 4;
+			break;
+
+		case -ERESTART_RESTARTBLOCK:
+			regs->regs[4] = regs->orig_a0;
+			regs->regs[11] = __NR_restart_syscall;
+			regs->csr_era -= 4;
+			break;
+		}
+		regs->regs[0] = 0;	/* Don't deal with this again.	*/
+	}
+
+	/*
+	 * If there's no signal to deliver, we just put the saved sigmask
+	 * back
+	 */
+	restore_saved_sigmask();
+}