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, 848 insertions, 0 deletions

diff --git a/tools/testing/selftests/cgroup/test_freezer.c b/tools/testing/selftests/cgroup/test_freezer.c
new file mode 100644
index 000000000..ff519029f
--- /dev/null
+++ b/tools/testing/selftests/cgroup/test_freezer.c
@@ -0,0 +1,848 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <stdbool.h>
+#include <linux/limits.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+
+#include "../kselftest.h"
+#include "cgroup_util.h"
+
+#define DEBUG
+#ifdef DEBUG
+#define debug(args...) fprintf(stderr, args)
+#else
+#define debug(args...)
+#endif
+
+/*
+ * Check if the cgroup is frozen by looking at the cgroup.events::frozen value.
+ */
+static int cg_check_frozen(const char *cgroup, bool frozen)
+{
+	if (frozen) {
+		if (cg_read_strstr(cgroup, "cgroup.events", "frozen 1") != 0) {
+			debug("Cgroup %s isn't frozen\n", cgroup);
+			return -1;
+		}
+	} else {
+		/*
+		 * Check the cgroup.events::frozen value.
+		 */
+		if (cg_read_strstr(cgroup, "cgroup.events", "frozen 0") != 0) {
+			debug("Cgroup %s is frozen\n", cgroup);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Freeze the given cgroup.
+ */
+static int cg_freeze_nowait(const char *cgroup, bool freeze)
+{
+	return cg_write(cgroup, "cgroup.freeze", freeze ? "1" : "0");
+}
+
+/*
+ * Attach a task to the given cgroup and wait for a cgroup frozen event.
+ * All transient events (e.g. populated) are ignored.
+ */
+static int cg_enter_and_wait_for_frozen(const char *cgroup, int pid,
+					bool frozen)
+{
+	int fd, ret = -1;
+	int attempts;
+
+	fd = cg_prepare_for_wait(cgroup);
+	if (fd < 0)
+		return fd;
+
+	ret = cg_enter(cgroup, pid);
+	if (ret)
+		goto out;
+
+	for (attempts = 0; attempts < 10; attempts++) {
+		ret = cg_wait_for(fd);
+		if (ret)
+			break;
+
+		ret = cg_check_frozen(cgroup, frozen);
+		if (ret)
+			continue;
+	}
+
+out:
+	close(fd);
+	return ret;
+}
+
+/*
+ * Freeze the given cgroup and wait for the inotify signal.
+ * If there are no events in 10 seconds, treat this as an error.
+ * Then check that the cgroup is in the desired state.
+ */
+static int cg_freeze_wait(const char *cgroup, bool freeze)
+{
+	int fd, ret = -1;
+
+	fd = cg_prepare_for_wait(cgroup);
+	if (fd < 0)
+		return fd;
+
+	ret = cg_freeze_nowait(cgroup, freeze);
+	if (ret) {
+		debug("Error: cg_freeze_nowait() failed\n");
+		goto out;
+	}
+
+	ret = cg_wait_for(fd);
+	if (ret)
+		goto out;
+
+	ret = cg_check_frozen(cgroup, freeze);
+out:
+	close(fd);
+	return ret;
+}
+
+/*
+ * A simple process running in a sleep loop until being
+ * re-parented.
+ */
+static int child_fn(const char *cgroup, void *arg)
+{
+	int ppid = getppid();
+
+	while (getppid() == ppid)
+		usleep(1000);
+
+	return getppid() == ppid;
+}
+
+/*
+ * A simple test for the cgroup freezer: populated the cgroup with 100
+ * running processes and freeze it. Then unfreeze it. Then it kills all
+ * processes and destroys the cgroup.
+ */
+static int test_cgfreezer_simple(const char *root)
+{
+	int ret = KSFT_FAIL;
+	char *cgroup = NULL;
+	int i;
+
+	cgroup = cg_name(root, "cg_test_simple");
+	if (!cgroup)
+		goto cleanup;
+
+	if (cg_create(cgroup))
+		goto cleanup;
+
+	for (i = 0; i < 100; i++)
+		cg_run_nowait(cgroup, child_fn, NULL);
+
+	if (cg_wait_for_proc_count(cgroup, 100))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup, false))
+		goto cleanup;
+
+	if (cg_freeze_wait(cgroup, true))
+		goto cleanup;
+
+	if (cg_freeze_wait(cgroup, false))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (cgroup)
+		cg_destroy(cgroup);
+	free(cgroup);
+	return ret;
+}
+
+/*
+ * The test creates the following hierarchy:
+ *       A
+ *    / / \ \
+ *   B  E  I K
+ *  /\  |
+ * C  D F
+ *      |
+ *      G
+ *      |
+ *      H
+ *
+ * with a process in C, H and 3 processes in K.
+ * Then it tries to freeze and unfreeze the whole tree.
+ */
+static int test_cgfreezer_tree(const char *root)
+{
+	char *cgroup[10] = {0};
+	int ret = KSFT_FAIL;
+	int i;
+
+	cgroup[0] = cg_name(root, "cg_test_tree_A");
+	if (!cgroup[0])
+		goto cleanup;
+
+	cgroup[1] = cg_name(cgroup[0], "B");
+	if (!cgroup[1])
+		goto cleanup;
+
+	cgroup[2] = cg_name(cgroup[1], "C");
+	if (!cgroup[2])
+		goto cleanup;
+
+	cgroup[3] = cg_name(cgroup[1], "D");
+	if (!cgroup[3])
+		goto cleanup;
+
+	cgroup[4] = cg_name(cgroup[0], "E");
+	if (!cgroup[4])
+		goto cleanup;
+
+	cgroup[5] = cg_name(cgroup[4], "F");
+	if (!cgroup[5])
+		goto cleanup;
+
+	cgroup[6] = cg_name(cgroup[5], "G");
+	if (!cgroup[6])
+		goto cleanup;
+
+	cgroup[7] = cg_name(cgroup[6], "H");
+	if (!cgroup[7])
+		goto cleanup;
+
+	cgroup[8] = cg_name(cgroup[0], "I");
+	if (!cgroup[8])
+		goto cleanup;
+
+	cgroup[9] = cg_name(cgroup[0], "K");
+	if (!cgroup[9])
+		goto cleanup;
+
+	for (i = 0; i < 10; i++)
+		if (cg_create(cgroup[i]))
+			goto cleanup;
+
+	cg_run_nowait(cgroup[2], child_fn, NULL);
+	cg_run_nowait(cgroup[7], child_fn, NULL);
+	cg_run_nowait(cgroup[9], child_fn, NULL);
+	cg_run_nowait(cgroup[9], child_fn, NULL);
+	cg_run_nowait(cgroup[9], child_fn, NULL);
+
+	/*
+	 * Wait until all child processes will enter
+	 * corresponding cgroups.
+	 */
+
+	if (cg_wait_for_proc_count(cgroup[2], 1) ||
+	    cg_wait_for_proc_count(cgroup[7], 1) ||
+	    cg_wait_for_proc_count(cgroup[9], 3))
+		goto cleanup;
+
+	/*
+	 * Freeze B.
+	 */
+	if (cg_freeze_wait(cgroup[1], true))
+		goto cleanup;
+
+	/*
+	 * Freeze F.
+	 */
+	if (cg_freeze_wait(cgroup[5], true))
+		goto cleanup;
+
+	/*
+	 * Freeze G.
+	 */
+	if (cg_freeze_wait(cgroup[6], true))
+		goto cleanup;
+
+	/*
+	 * Check that A and E are not frozen.
+	 */
+	if (cg_check_frozen(cgroup[0], false))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[4], false))
+		goto cleanup;
+
+	/*
+	 * Freeze A. Check that A, B and E are frozen.
+	 */
+	if (cg_freeze_wait(cgroup[0], true))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[1], true))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[4], true))
+		goto cleanup;
+
+	/*
+	 * Unfreeze B, F and G
+	 */
+	if (cg_freeze_nowait(cgroup[1], false))
+		goto cleanup;
+
+	if (cg_freeze_nowait(cgroup[5], false))
+		goto cleanup;
+
+	if (cg_freeze_nowait(cgroup[6], false))
+		goto cleanup;
+
+	/*
+	 * Check that C and H are still frozen.
+	 */
+	if (cg_check_frozen(cgroup[2], true))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[7], true))
+		goto cleanup;
+
+	/*
+	 * Unfreeze A. Check that A, C and K are not frozen.
+	 */
+	if (cg_freeze_wait(cgroup[0], false))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[2], false))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[9], false))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	for (i = 9; i >= 0 && cgroup[i]; i--) {
+		cg_destroy(cgroup[i]);
+		free(cgroup[i]);
+	}
+
+	return ret;
+}
+
+/*
+ * A fork bomb emulator.
+ */
+static int forkbomb_fn(const char *cgroup, void *arg)
+{
+	int ppid;
+
+	fork();
+	fork();
+
+	ppid = getppid();
+
+	while (getppid() == ppid)
+		usleep(1000);
+
+	return getppid() == ppid;
+}
+
+/*
+ * The test runs a fork bomb in a cgroup and tries to freeze it.
+ * Then it kills all processes and checks that cgroup isn't populated
+ * anymore.
+ */
+static int test_cgfreezer_forkbomb(const char *root)
+{
+	int ret = KSFT_FAIL;
+	char *cgroup = NULL;
+
+	cgroup = cg_name(root, "cg_forkbomb_test");
+	if (!cgroup)
+		goto cleanup;
+
+	if (cg_create(cgroup))
+		goto cleanup;
+
+	cg_run_nowait(cgroup, forkbomb_fn, NULL);
+
+	usleep(100000);
+
+	if (cg_freeze_wait(cgroup, true))
+		goto cleanup;
+
+	if (cg_killall(cgroup))
+		goto cleanup;
+
+	if (cg_wait_for_proc_count(cgroup, 0))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (cgroup)
+		cg_destroy(cgroup);
+	free(cgroup);
+	return ret;
+}
+
+/*
+ * The test creates a cgroups and freezes it. Then it creates a child cgroup
+ * and populates it with a task. After that it checks that the child cgroup
+ * is frozen and the parent cgroup remains frozen too.
+ */
+static int test_cgfreezer_mkdir(const char *root)
+{
+	int ret = KSFT_FAIL;
+	char *parent, *child = NULL;
+	int pid;
+
+	parent = cg_name(root, "cg_test_mkdir_A");
+	if (!parent)
+		goto cleanup;
+
+	child = cg_name(parent, "cg_test_mkdir_B");
+	if (!child)
+		goto cleanup;
+
+	if (cg_create(parent))
+		goto cleanup;
+
+	if (cg_freeze_wait(parent, true))
+		goto cleanup;
+
+	if (cg_create(child))
+		goto cleanup;
+
+	pid = cg_run_nowait(child, child_fn, NULL);
+	if (pid < 0)
+		goto cleanup;
+
+	if (cg_wait_for_proc_count(child, 1))
+		goto cleanup;
+
+	if (cg_check_frozen(child, true))
+		goto cleanup;
+
+	if (cg_check_frozen(parent, true))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (child)
+		cg_destroy(child);
+	free(child);
+	if (parent)
+		cg_destroy(parent);
+	free(parent);
+	return ret;
+}
+
+/*
+ * The test creates two nested cgroups, freezes the parent
+ * and removes the child. Then it checks that the parent cgroup
+ * remains frozen and it's possible to create a new child
+ * without unfreezing. The new child is frozen too.
+ */
+static int test_cgfreezer_rmdir(const char *root)
+{
+	int ret = KSFT_FAIL;
+	char *parent, *child = NULL;
+
+	parent = cg_name(root, "cg_test_rmdir_A");
+	if (!parent)
+		goto cleanup;
+
+	child = cg_name(parent, "cg_test_rmdir_B");
+	if (!child)
+		goto cleanup;
+
+	if (cg_create(parent))
+		goto cleanup;
+
+	if (cg_create(child))
+		goto cleanup;
+
+	if (cg_freeze_wait(parent, true))
+		goto cleanup;
+
+	if (cg_destroy(child))
+		goto cleanup;
+
+	if (cg_check_frozen(parent, true))
+		goto cleanup;
+
+	if (cg_create(child))
+		goto cleanup;
+
+	if (cg_check_frozen(child, true))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (child)
+		cg_destroy(child);
+	free(child);
+	if (parent)
+		cg_destroy(parent);
+	free(parent);
+	return ret;
+}
+
+/*
+ * The test creates two cgroups: A and B, runs a process in A
+ * and performs several migrations:
+ * 1) A (running) -> B (frozen)
+ * 2) B (frozen) -> A (running)
+ * 3) A (frozen) -> B (frozen)
+ *
+ * On each step it checks the actual state of both cgroups.
+ */
+static int test_cgfreezer_migrate(const char *root)
+{
+	int ret = KSFT_FAIL;
+	char *cgroup[2] = {0};
+	int pid;
+
+	cgroup[0] = cg_name(root, "cg_test_migrate_A");
+	if (!cgroup[0])
+		goto cleanup;
+
+	cgroup[1] = cg_name(root, "cg_test_migrate_B");
+	if (!cgroup[1])
+		goto cleanup;
+
+	if (cg_create(cgroup[0]))
+		goto cleanup;
+
+	if (cg_create(cgroup[1]))
+		goto cleanup;
+
+	pid = cg_run_nowait(cgroup[0], child_fn, NULL);
+	if (pid < 0)
+		goto cleanup;
+
+	if (cg_wait_for_proc_count(cgroup[0], 1))
+		goto cleanup;
+
+	/*
+	 * Migrate from A (running) to B (frozen)
+	 */
+	if (cg_freeze_wait(cgroup[1], true))
+		goto cleanup;
+
+	if (cg_enter_and_wait_for_frozen(cgroup[1], pid, true))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[0], false))
+		goto cleanup;
+
+	/*
+	 * Migrate from B (frozen) to A (running)
+	 */
+	if (cg_enter_and_wait_for_frozen(cgroup[0], pid, false))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[1], true))
+		goto cleanup;
+
+	/*
+	 * Migrate from A (frozen) to B (frozen)
+	 */
+	if (cg_freeze_wait(cgroup[0], true))
+		goto cleanup;
+
+	if (cg_enter_and_wait_for_frozen(cgroup[1], pid, true))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup[0], true))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (cgroup[0])
+		cg_destroy(cgroup[0]);
+	free(cgroup[0]);
+	if (cgroup[1])
+		cg_destroy(cgroup[1]);
+	free(cgroup[1]);
+	return ret;
+}
+
+/*
+ * The test checks that ptrace works with a tracing process in a frozen cgroup.
+ */
+static int test_cgfreezer_ptrace(const char *root)
+{
+	int ret = KSFT_FAIL;
+	char *cgroup = NULL;
+	siginfo_t siginfo;
+	int pid;
+
+	cgroup = cg_name(root, "cg_test_ptrace");
+	if (!cgroup)
+		goto cleanup;
+
+	if (cg_create(cgroup))
+		goto cleanup;
+
+	pid = cg_run_nowait(cgroup, child_fn, NULL);
+	if (pid < 0)
+		goto cleanup;
+
+	if (cg_wait_for_proc_count(cgroup, 1))
+		goto cleanup;
+
+	if (cg_freeze_wait(cgroup, true))
+		goto cleanup;
+
+	if (ptrace(PTRACE_SEIZE, pid, NULL, NULL))
+		goto cleanup;
+
+	if (ptrace(PTRACE_INTERRUPT, pid, NULL, NULL))
+		goto cleanup;
+
+	waitpid(pid, NULL, 0);
+
+	/*
+	 * Cgroup has to remain frozen, however the test task
+	 * is in traced state.
+	 */
+	if (cg_check_frozen(cgroup, true))
+		goto cleanup;
+
+	if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo))
+		goto cleanup;
+
+	if (ptrace(PTRACE_DETACH, pid, NULL, NULL))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup, true))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (cgroup)
+		cg_destroy(cgroup);
+	free(cgroup);
+	return ret;
+}
+
+/*
+ * Check if the process is stopped.
+ */
+static int proc_check_stopped(int pid)
+{
+	char buf[PAGE_SIZE];
+	int len;
+
+	len = proc_read_text(pid, 0, "stat", buf, sizeof(buf));
+	if (len == -1) {
+		debug("Can't get %d stat\n", pid);
+		return -1;
+	}
+
+	if (strstr(buf, "(test_freezer) T ") == NULL) {
+		debug("Process %d in the unexpected state: %s\n", pid, buf);
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Test that it's possible to freeze a cgroup with a stopped process.
+ */
+static int test_cgfreezer_stopped(const char *root)
+{
+	int pid, ret = KSFT_FAIL;
+	char *cgroup = NULL;
+
+	cgroup = cg_name(root, "cg_test_stopped");
+	if (!cgroup)
+		goto cleanup;
+
+	if (cg_create(cgroup))
+		goto cleanup;
+
+	pid = cg_run_nowait(cgroup, child_fn, NULL);
+
+	if (cg_wait_for_proc_count(cgroup, 1))
+		goto cleanup;
+
+	if (kill(pid, SIGSTOP))
+		goto cleanup;
+
+	if (cg_check_frozen(cgroup, false))
+		goto cleanup;
+
+	if (cg_freeze_wait(cgroup, true))
+		goto cleanup;
+
+	if (cg_freeze_wait(cgroup, false))
+		goto cleanup;
+
+	if (proc_check_stopped(pid))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (cgroup)
+		cg_destroy(cgroup);
+	free(cgroup);
+	return ret;
+}
+
+/*
+ * Test that it's possible to freeze a cgroup with a ptraced process.
+ */
+static int test_cgfreezer_ptraced(const char *root)
+{
+	int pid, ret = KSFT_FAIL;
+	char *cgroup = NULL;
+	siginfo_t siginfo;
+
+	cgroup = cg_name(root, "cg_test_ptraced");
+	if (!cgroup)
+		goto cleanup;
+
+	if (cg_create(cgroup))
+		goto cleanup;
+
+	pid = cg_run_nowait(cgroup, child_fn, NULL);
+
+	if (cg_wait_for_proc_count(cgroup, 1))
+		goto cleanup;
+
+	if (ptrace(PTRACE_SEIZE, pid, NULL, NULL))
+		goto cleanup;
+
+	if (ptrace(PTRACE_INTERRUPT, pid, NULL, NULL))
+		goto cleanup;
+
+	waitpid(pid, NULL, 0);
+
+	if (cg_check_frozen(cgroup, false))
+		goto cleanup;
+
+	if (cg_freeze_wait(cgroup, true))
+		goto cleanup;
+
+	/*
+	 * cg_check_frozen(cgroup, true) will fail here,
+	 * because the task in in the TRACEd state.
+	 */
+	if (cg_freeze_wait(cgroup, false))
+		goto cleanup;
+
+	if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo))
+		goto cleanup;
+
+	if (ptrace(PTRACE_DETACH, pid, NULL, NULL))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (cgroup)
+		cg_destroy(cgroup);
+	free(cgroup);
+	return ret;
+}
+
+static int vfork_fn(const char *cgroup, void *arg)
+{
+	int pid = vfork();
+
+	if (pid == 0)
+		while (true)
+			sleep(1);
+
+	return pid;
+}
+
+/*
+ * Test that it's possible to freeze a cgroup with a process,
+ * which called vfork() and is waiting for a child.
+ */
+static int test_cgfreezer_vfork(const char *root)
+{
+	int ret = KSFT_FAIL;
+	char *cgroup = NULL;
+
+	cgroup = cg_name(root, "cg_test_vfork");
+	if (!cgroup)
+		goto cleanup;
+
+	if (cg_create(cgroup))
+		goto cleanup;
+
+	cg_run_nowait(cgroup, vfork_fn, NULL);
+
+	if (cg_wait_for_proc_count(cgroup, 2))
+		goto cleanup;
+
+	if (cg_freeze_wait(cgroup, true))
+		goto cleanup;
+
+	ret = KSFT_PASS;
+
+cleanup:
+	if (cgroup)
+		cg_destroy(cgroup);
+	free(cgroup);
+	return ret;
+}
+
+#define T(x) { x, #x }
+struct cgfreezer_test {
+	int (*fn)(const char *root);
+	const char *name;
+} tests[] = {
+	T(test_cgfreezer_simple),
+	T(test_cgfreezer_tree),
+	T(test_cgfreezer_forkbomb),
+	T(test_cgfreezer_mkdir),
+	T(test_cgfreezer_rmdir),
+	T(test_cgfreezer_migrate),
+	T(test_cgfreezer_ptrace),
+	T(test_cgfreezer_stopped),
+	T(test_cgfreezer_ptraced),
+	T(test_cgfreezer_vfork),
+};
+#undef T
+
+int main(int argc, char *argv[])
+{
+	char root[PATH_MAX];
+	int i, ret = EXIT_SUCCESS;
+
+	if (cg_find_unified_root(root, sizeof(root)))
+		ksft_exit_skip("cgroup v2 isn't mounted\n");
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		switch (tests[i].fn(root)) {
+		case KSFT_PASS:
+			ksft_test_result_pass("%s\n", tests[i].name);
+			break;
+		case KSFT_SKIP:
+			ksft_test_result_skip("%s\n", tests[i].name);
+			break;
+		default:
+			ret = EXIT_FAILURE;
+			ksft_test_result_fail("%s\n", tests[i].name);
+			break;
+		}
+	}
+
+	return ret;
+}