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, 707 insertions, 0 deletions

diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
new file mode 100644
index 000000000..fc4450db5
--- /dev/null
+++ b/arch/um/os-Linux/file.c
@@ -0,0 +1,707 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <linux/falloc.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/un.h>
+#include <sys/types.h>
+#include <sys/eventfd.h>
+#include <poll.h>
+#include <os.h>
+
+static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
+{
+	*dst = ((struct uml_stat) {
+		.ust_dev     = src->st_dev,     /* device */
+		.ust_ino     = src->st_ino,     /* inode */
+		.ust_mode    = src->st_mode,    /* protection */
+		.ust_nlink   = src->st_nlink,   /* number of hard links */
+		.ust_uid     = src->st_uid,     /* user ID of owner */
+		.ust_gid     = src->st_gid,     /* group ID of owner */
+		.ust_size    = src->st_size,    /* total size, in bytes */
+		.ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
+		.ust_blocks  = src->st_blocks,  /* number of blocks allocated */
+		.ust_atime   = src->st_atime,   /* time of last access */
+		.ust_mtime   = src->st_mtime,   /* time of last modification */
+		.ust_ctime   = src->st_ctime,   /* time of last change */
+	});
+}
+
+int os_stat_fd(const int fd, struct uml_stat *ubuf)
+{
+	struct stat64 sbuf;
+	int err;
+
+	CATCH_EINTR(err = fstat64(fd, &sbuf));
+	if (err < 0)
+		return -errno;
+
+	if (ubuf != NULL)
+		copy_stat(ubuf, &sbuf);
+	return err;
+}
+
+int os_stat_file(const char *file_name, struct uml_stat *ubuf)
+{
+	struct stat64 sbuf;
+	int err;
+
+	CATCH_EINTR(err = stat64(file_name, &sbuf));
+	if (err < 0)
+		return -errno;
+
+	if (ubuf != NULL)
+		copy_stat(ubuf, &sbuf);
+	return err;
+}
+
+int os_access(const char *file, int mode)
+{
+	int amode, err;
+
+	amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
+		(mode & OS_ACC_W_OK ? W_OK : 0) |
+		(mode & OS_ACC_X_OK ? X_OK : 0) |
+		(mode & OS_ACC_F_OK ? F_OK : 0);
+
+	err = access(file, amode);
+	if (err < 0)
+		return -errno;
+
+	return 0;
+}
+
+/* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
+int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
+{
+	int err;
+
+	err = ioctl(fd, cmd, arg);
+	if (err < 0)
+		return -errno;
+
+	return err;
+}
+
+/* FIXME: ensure namebuf in os_get_if_name is big enough */
+int os_get_ifname(int fd, char* namebuf)
+{
+	if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
+		return -errno;
+
+	return 0;
+}
+
+int os_set_slip(int fd)
+{
+	int disc, sencap;
+
+	disc = N_SLIP;
+	if (ioctl(fd, TIOCSETD, &disc) < 0)
+		return -errno;
+
+	sencap = 0;
+	if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
+		return -errno;
+
+	return 0;
+}
+
+int os_mode_fd(int fd, int mode)
+{
+	int err;
+
+	CATCH_EINTR(err = fchmod(fd, mode));
+	if (err < 0)
+		return -errno;
+
+	return 0;
+}
+
+int os_file_type(char *file)
+{
+	struct uml_stat buf;
+	int err;
+
+	err = os_stat_file(file, &buf);
+	if (err < 0)
+		return err;
+
+	if (S_ISDIR(buf.ust_mode))
+		return OS_TYPE_DIR;
+	else if (S_ISLNK(buf.ust_mode))
+		return OS_TYPE_SYMLINK;
+	else if (S_ISCHR(buf.ust_mode))
+		return OS_TYPE_CHARDEV;
+	else if (S_ISBLK(buf.ust_mode))
+		return OS_TYPE_BLOCKDEV;
+	else if (S_ISFIFO(buf.ust_mode))
+		return OS_TYPE_FIFO;
+	else if (S_ISSOCK(buf.ust_mode))
+		return OS_TYPE_SOCK;
+	else return OS_TYPE_FILE;
+}
+
+int os_file_mode(const char *file, struct openflags *mode_out)
+{
+	int err;
+
+	*mode_out = OPENFLAGS();
+
+	err = access(file, W_OK);
+	if (err && (errno != EACCES))
+		return -errno;
+	else if (!err)
+		*mode_out = of_write(*mode_out);
+
+	err = access(file, R_OK);
+	if (err && (errno != EACCES))
+		return -errno;
+	else if (!err)
+		*mode_out = of_read(*mode_out);
+
+	return err;
+}
+
+int os_open_file(const char *file, struct openflags flags, int mode)
+{
+	int fd, err, f = 0;
+
+	if (flags.r && flags.w)
+		f = O_RDWR;
+	else if (flags.r)
+		f = O_RDONLY;
+	else if (flags.w)
+		f = O_WRONLY;
+	else f = 0;
+
+	if (flags.s)
+		f |= O_SYNC;
+	if (flags.c)
+		f |= O_CREAT;
+	if (flags.t)
+		f |= O_TRUNC;
+	if (flags.e)
+		f |= O_EXCL;
+	if (flags.a)
+		f |= O_APPEND;
+
+	fd = open64(file, f, mode);
+	if (fd < 0)
+		return -errno;
+
+	if (flags.cl && fcntl(fd, F_SETFD, 1)) {
+		err = -errno;
+		close(fd);
+		return err;
+	}
+
+	return fd;
+}
+
+int os_connect_socket(const char *name)
+{
+	struct sockaddr_un sock;
+	int fd, err;
+
+	sock.sun_family = AF_UNIX;
+	snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
+
+	fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd < 0) {
+		err = -errno;
+		goto out;
+	}
+
+	err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
+	if (err) {
+		err = -errno;
+		goto out_close;
+	}
+
+	return fd;
+
+out_close:
+	close(fd);
+out:
+	return err;
+}
+
+void os_close_file(int fd)
+{
+	close(fd);
+}
+int os_fsync_file(int fd)
+{
+	if (fsync(fd) < 0)
+	    return -errno;
+	return 0;
+}
+
+int os_seek_file(int fd, unsigned long long offset)
+{
+	unsigned long long actual;
+
+	actual = lseek64(fd, offset, SEEK_SET);
+	if (actual != offset)
+		return -errno;
+	return 0;
+}
+
+int os_read_file(int fd, void *buf, int len)
+{
+	int n = read(fd, buf, len);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
+int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
+{
+	int n = pread(fd, buf, len, offset);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
+int os_write_file(int fd, const void *buf, int len)
+{
+	int n = write(fd, (void *) buf, len);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
+int os_sync_file(int fd)
+{
+	int n = fdatasync(fd);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
+int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
+{
+	int n = pwrite(fd, (void *) buf, len, offset);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
+
+int os_file_size(const char *file, unsigned long long *size_out)
+{
+	struct uml_stat buf;
+	int err;
+
+	err = os_stat_file(file, &buf);
+	if (err < 0) {
+		printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
+		       -err);
+		return err;
+	}
+
+	if (S_ISBLK(buf.ust_mode)) {
+		int fd;
+		long blocks;
+
+		fd = open(file, O_RDONLY, 0);
+		if (fd < 0) {
+			err = -errno;
+			printk(UM_KERN_ERR "Couldn't open \"%s\", "
+			       "errno = %d\n", file, errno);
+			return err;
+		}
+		if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
+			err = -errno;
+			printk(UM_KERN_ERR "Couldn't get the block size of "
+			       "\"%s\", errno = %d\n", file, errno);
+			close(fd);
+			return err;
+		}
+		*size_out = ((long long) blocks) * 512;
+		close(fd);
+	}
+	else *size_out = buf.ust_size;
+
+	return 0;
+}
+
+int os_file_modtime(const char *file, long long *modtime)
+{
+	struct uml_stat buf;
+	int err;
+
+	err = os_stat_file(file, &buf);
+	if (err < 0) {
+		printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
+		       -err);
+		return err;
+	}
+
+	*modtime = buf.ust_mtime;
+	return 0;
+}
+
+int os_set_exec_close(int fd)
+{
+	int err;
+
+	CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
+
+	if (err < 0)
+		return -errno;
+	return err;
+}
+
+int os_pipe(int *fds, int stream, int close_on_exec)
+{
+	int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
+
+	err = socketpair(AF_UNIX, type, 0, fds);
+	if (err < 0)
+		return -errno;
+
+	if (!close_on_exec)
+		return 0;
+
+	err = os_set_exec_close(fds[0]);
+	if (err < 0)
+		goto error;
+
+	err = os_set_exec_close(fds[1]);
+	if (err < 0)
+		goto error;
+
+	return 0;
+
+ error:
+	printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
+	       -err);
+	close(fds[1]);
+	close(fds[0]);
+	return err;
+}
+
+int os_set_fd_async(int fd)
+{
+	int err, flags;
+
+	flags = fcntl(fd, F_GETFL);
+	if (flags < 0)
+		return -errno;
+
+	flags |= O_ASYNC | O_NONBLOCK;
+	if (fcntl(fd, F_SETFL, flags) < 0) {
+		err = -errno;
+		printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
+		       "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
+		return err;
+	}
+
+	if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
+	    (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
+		err = -errno;
+		printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
+		       "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
+		return err;
+	}
+
+	return 0;
+}
+
+int os_clear_fd_async(int fd)
+{
+	int flags;
+
+	flags = fcntl(fd, F_GETFL);
+	if (flags < 0)
+		return -errno;
+
+	flags &= ~(O_ASYNC | O_NONBLOCK);
+	if (fcntl(fd, F_SETFL, flags) < 0)
+		return -errno;
+	return 0;
+}
+
+int os_set_fd_block(int fd, int blocking)
+{
+	int flags;
+
+	flags = fcntl(fd, F_GETFL);
+	if (flags < 0)
+		return -errno;
+
+	if (blocking)
+		flags &= ~O_NONBLOCK;
+	else
+		flags |= O_NONBLOCK;
+
+	if (fcntl(fd, F_SETFL, flags) < 0)
+		return -errno;
+
+	return 0;
+}
+
+int os_accept_connection(int fd)
+{
+	int new;
+
+	new = accept(fd, NULL, 0);
+	if (new < 0)
+		return -errno;
+	return new;
+}
+
+#ifndef SHUT_RD
+#define SHUT_RD 0
+#endif
+
+#ifndef SHUT_WR
+#define SHUT_WR 1
+#endif
+
+#ifndef SHUT_RDWR
+#define SHUT_RDWR 2
+#endif
+
+int os_shutdown_socket(int fd, int r, int w)
+{
+	int what, err;
+
+	if (r && w)
+		what = SHUT_RDWR;
+	else if (r)
+		what = SHUT_RD;
+	else if (w)
+		what = SHUT_WR;
+	else
+		return -EINVAL;
+
+	err = shutdown(fd, what);
+	if (err < 0)
+		return -errno;
+	return 0;
+}
+
+int os_rcv_fd(int fd, int *helper_pid_out)
+{
+	int new, n;
+	char buf[CMSG_SPACE(sizeof(new))];
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	struct iovec iov;
+
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	iov = ((struct iovec) { .iov_base  = helper_pid_out,
+				.iov_len   = sizeof(*helper_pid_out) });
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = buf;
+	msg.msg_controllen = sizeof(buf);
+	msg.msg_flags = 0;
+
+	n = recvmsg(fd, &msg, 0);
+	if (n < 0)
+		return -errno;
+	else if (n != iov.iov_len)
+		*helper_pid_out = -1;
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (cmsg == NULL) {
+		printk(UM_KERN_ERR "rcv_fd didn't receive anything, "
+		       "error = %d\n", errno);
+		return -1;
+	}
+	if ((cmsg->cmsg_level != SOL_SOCKET) ||
+	    (cmsg->cmsg_type != SCM_RIGHTS)) {
+		printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n");
+		return -1;
+	}
+
+	new = ((int *) CMSG_DATA(cmsg))[0];
+	return new;
+}
+
+int os_create_unix_socket(const char *file, int len, int close_on_exec)
+{
+	struct sockaddr_un addr;
+	int sock, err;
+
+	sock = socket(PF_UNIX, SOCK_DGRAM, 0);
+	if (sock < 0)
+		return -errno;
+
+	if (close_on_exec) {
+		err = os_set_exec_close(sock);
+		if (err < 0)
+			printk(UM_KERN_ERR "create_unix_socket : "
+			       "close_on_exec failed, err = %d", -err);
+	}
+
+	addr.sun_family = AF_UNIX;
+
+	snprintf(addr.sun_path, len, "%s", file);
+
+	err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
+	if (err < 0)
+		return -errno;
+
+	return sock;
+}
+
+void os_flush_stdout(void)
+{
+	fflush(stdout);
+}
+
+int os_lock_file(int fd, int excl)
+{
+	int type = excl ? F_WRLCK : F_RDLCK;
+	struct flock lock = ((struct flock) { .l_type	= type,
+					      .l_whence	= SEEK_SET,
+					      .l_start	= 0,
+					      .l_len	= 0 } );
+	int err, save;
+
+	err = fcntl(fd, F_SETLK, &lock);
+	if (!err)
+		goto out;
+
+	save = -errno;
+	err = fcntl(fd, F_GETLK, &lock);
+	if (err) {
+		err = -errno;
+		goto out;
+	}
+
+	printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
+	       lock.l_pid);
+	err = save;
+ out:
+	return err;
+}
+
+unsigned os_major(unsigned long long dev)
+{
+	return major(dev);
+}
+
+unsigned os_minor(unsigned long long dev)
+{
+	return minor(dev);
+}
+
+unsigned long long os_makedev(unsigned major, unsigned minor)
+{
+	return makedev(major, minor);
+}
+
+int os_falloc_punch(int fd, unsigned long long offset, int len)
+{
+	int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
+int os_falloc_zeroes(int fd, unsigned long long offset, int len)
+{
+	int n = fallocate(fd, FALLOC_FL_ZERO_RANGE|FALLOC_FL_KEEP_SIZE, offset, len);
+
+	if (n < 0)
+		return -errno;
+	return n;
+}
+
+int os_eventfd(unsigned int initval, int flags)
+{
+	int fd = eventfd(initval, flags);
+
+	if (fd < 0)
+		return -errno;
+	return fd;
+}
+
+int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
+		   unsigned int fds_num)
+{
+	struct iovec iov = {
+		.iov_base = (void *) buf,
+		.iov_len = len,
+	};
+	union {
+		char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)];
+		struct cmsghdr align;
+	} u;
+	unsigned int fds_size = sizeof(*fds) * fds_num;
+	struct msghdr msg = {
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+		.msg_control = u.control,
+		.msg_controllen = CMSG_SPACE(fds_size),
+	};
+	struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
+	int err;
+
+	if (fds_num > OS_SENDMSG_MAX_FDS)
+		return -EINVAL;
+	memset(u.control, 0, sizeof(u.control));
+	cmsg->cmsg_level = SOL_SOCKET;
+	cmsg->cmsg_type = SCM_RIGHTS;
+	cmsg->cmsg_len = CMSG_LEN(fds_size);
+	memcpy(CMSG_DATA(cmsg), fds, fds_size);
+	err = sendmsg(fd, &msg, 0);
+
+	if (err < 0)
+		return -errno;
+	return err;
+}
+
+int os_poll(unsigned int n, const int *fds)
+{
+	/* currently need 2 FDs at most so avoid dynamic allocation */
+	struct pollfd pollfds[2] = {};
+	unsigned int i;
+	int ret;
+
+	if (n > ARRAY_SIZE(pollfds))
+		return -EINVAL;
+
+	for (i = 0; i < n; i++) {
+		pollfds[i].fd = fds[i];
+		pollfds[i].events = POLLIN;
+	}
+
+	ret = poll(pollfds, n, -1);
+	if (ret < 0)
+		return -errno;
+
+	/* Return the index of the available FD */
+	for (i = 0; i < n; i++) {
+		if (pollfds[i].revents)
+			return i;
+	}
+
+	return -EIO;
+}