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, 696 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c
new file mode 100644
index 000000000..3a13e102c
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/user_ringbuf.c
@@ -0,0 +1,696 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#define _GNU_SOURCE
+#include <linux/compiler.h>
+#include <linux/ring_buffer.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/syscall.h>
+#include <sys/sysinfo.h>
+#include <test_progs.h>
+#include <uapi/linux/bpf.h>
+#include <unistd.h>
+
+#include "user_ringbuf_fail.skel.h"
+#include "user_ringbuf_success.skel.h"
+
+#include "../progs/test_user_ringbuf.h"
+
+static const long c_sample_size = sizeof(struct sample) + BPF_RINGBUF_HDR_SZ;
+static const long c_ringbuf_size = 1 << 12; /* 1 small page */
+static const long c_max_entries = c_ringbuf_size / c_sample_size;
+
+static void drain_current_samples(void)
+{
+	syscall(__NR_getpgid);
+}
+
+static int write_samples(struct user_ring_buffer *ringbuf, uint32_t num_samples)
+{
+	int i, err = 0;
+
+	/* Write some number of samples to the ring buffer. */
+	for (i = 0; i < num_samples; i++) {
+		struct sample *entry;
+		int read;
+
+		entry = user_ring_buffer__reserve(ringbuf, sizeof(*entry));
+		if (!entry) {
+			err = -errno;
+			goto done;
+		}
+
+		entry->pid = getpid();
+		entry->seq = i;
+		entry->value = i * i;
+
+		read = snprintf(entry->comm, sizeof(entry->comm), "%u", i);
+		if (read <= 0) {
+			/* Assert on the error path to avoid spamming logs with
+			 * mostly success messages.
+			 */
+			ASSERT_GT(read, 0, "snprintf_comm");
+			err = read;
+			user_ring_buffer__discard(ringbuf, entry);
+			goto done;
+		}
+
+		user_ring_buffer__submit(ringbuf, entry);
+	}
+
+done:
+	drain_current_samples();
+
+	return err;
+}
+
+static struct user_ringbuf_success *open_load_ringbuf_skel(void)
+{
+	struct user_ringbuf_success *skel;
+	int err;
+
+	skel = user_ringbuf_success__open();
+	if (!ASSERT_OK_PTR(skel, "skel_open"))
+		return NULL;
+
+	err = bpf_map__set_max_entries(skel->maps.user_ringbuf, c_ringbuf_size);
+	if (!ASSERT_OK(err, "set_max_entries"))
+		goto cleanup;
+
+	err = bpf_map__set_max_entries(skel->maps.kernel_ringbuf, c_ringbuf_size);
+	if (!ASSERT_OK(err, "set_max_entries"))
+		goto cleanup;
+
+	err = user_ringbuf_success__load(skel);
+	if (!ASSERT_OK(err, "skel_load"))
+		goto cleanup;
+
+	return skel;
+
+cleanup:
+	user_ringbuf_success__destroy(skel);
+	return NULL;
+}
+
+static void test_user_ringbuf_mappings(void)
+{
+	int err, rb_fd;
+	int page_size = getpagesize();
+	void *mmap_ptr;
+	struct user_ringbuf_success *skel;
+
+	skel = open_load_ringbuf_skel();
+	if (!skel)
+		return;
+
+	rb_fd = bpf_map__fd(skel->maps.user_ringbuf);
+	/* cons_pos can be mapped R/O, can't add +X with mprotect. */
+	mmap_ptr = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rb_fd, 0);
+	ASSERT_OK_PTR(mmap_ptr, "ro_cons_pos");
+	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_WRITE), "write_cons_pos_protect");
+	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_cons_pos_protect");
+	ASSERT_ERR_PTR(mremap(mmap_ptr, 0, 4 * page_size, MREMAP_MAYMOVE), "wr_prod_pos");
+	err = -errno;
+	ASSERT_ERR(err, "wr_prod_pos_err");
+	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_ro_cons");
+
+	/* prod_pos can be mapped RW, can't add +X with mprotect. */
+	mmap_ptr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
+			rb_fd, page_size);
+	ASSERT_OK_PTR(mmap_ptr, "rw_prod_pos");
+	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_prod_pos_protect");
+	err = -errno;
+	ASSERT_ERR(err, "wr_prod_pos_err");
+	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_rw_prod");
+
+	/* data pages can be mapped RW, can't add +X with mprotect. */
+	mmap_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd,
+			2 * page_size);
+	ASSERT_OK_PTR(mmap_ptr, "rw_data");
+	ASSERT_ERR(mprotect(mmap_ptr, page_size, PROT_EXEC), "exec_data_protect");
+	err = -errno;
+	ASSERT_ERR(err, "exec_data_err");
+	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_rw_data");
+
+	user_ringbuf_success__destroy(skel);
+}
+
+static int load_skel_create_ringbufs(struct user_ringbuf_success **skel_out,
+				     struct ring_buffer **kern_ringbuf_out,
+				     ring_buffer_sample_fn callback,
+				     struct user_ring_buffer **user_ringbuf_out)
+{
+	struct user_ringbuf_success *skel;
+	struct ring_buffer *kern_ringbuf = NULL;
+	struct user_ring_buffer *user_ringbuf = NULL;
+	int err = -ENOMEM, rb_fd;
+
+	skel = open_load_ringbuf_skel();
+	if (!skel)
+		return err;
+
+	/* only trigger BPF program for current process */
+	skel->bss->pid = getpid();
+
+	if (kern_ringbuf_out) {
+		rb_fd = bpf_map__fd(skel->maps.kernel_ringbuf);
+		kern_ringbuf = ring_buffer__new(rb_fd, callback, skel, NULL);
+		if (!ASSERT_OK_PTR(kern_ringbuf, "kern_ringbuf_create"))
+			goto cleanup;
+
+		*kern_ringbuf_out = kern_ringbuf;
+	}
+
+	if (user_ringbuf_out) {
+		rb_fd = bpf_map__fd(skel->maps.user_ringbuf);
+		user_ringbuf = user_ring_buffer__new(rb_fd, NULL);
+		if (!ASSERT_OK_PTR(user_ringbuf, "user_ringbuf_create"))
+			goto cleanup;
+
+		*user_ringbuf_out = user_ringbuf;
+		ASSERT_EQ(skel->bss->read, 0, "no_reads_after_load");
+	}
+
+	err = user_ringbuf_success__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto cleanup;
+
+	*skel_out = skel;
+	return 0;
+
+cleanup:
+	if (kern_ringbuf_out)
+		*kern_ringbuf_out = NULL;
+	if (user_ringbuf_out)
+		*user_ringbuf_out = NULL;
+	ring_buffer__free(kern_ringbuf);
+	user_ring_buffer__free(user_ringbuf);
+	user_ringbuf_success__destroy(skel);
+	return err;
+}
+
+static int load_skel_create_user_ringbuf(struct user_ringbuf_success **skel_out,
+					 struct user_ring_buffer **ringbuf_out)
+{
+	return load_skel_create_ringbufs(skel_out, NULL, NULL, ringbuf_out);
+}
+
+static void manually_write_test_invalid_sample(struct user_ringbuf_success *skel,
+					       __u32 size, __u64 producer_pos, int err)
+{
+	void *data_ptr;
+	__u64 *producer_pos_ptr;
+	int rb_fd, page_size = getpagesize();
+
+	rb_fd = bpf_map__fd(skel->maps.user_ringbuf);
+
+	ASSERT_EQ(skel->bss->read, 0, "num_samples_before_bad_sample");
+
+	/* Map the producer_pos as RW. */
+	producer_pos_ptr = mmap(NULL, page_size, PROT_READ | PROT_WRITE,
+				MAP_SHARED, rb_fd, page_size);
+	ASSERT_OK_PTR(producer_pos_ptr, "producer_pos_ptr");
+
+	/* Map the data pages as RW. */
+	data_ptr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, rb_fd, 2 * page_size);
+	ASSERT_OK_PTR(data_ptr, "rw_data");
+
+	memset(data_ptr, 0, BPF_RINGBUF_HDR_SZ);
+	*(__u32 *)data_ptr = size;
+
+	/* Synchronizes with smp_load_acquire() in __bpf_user_ringbuf_peek() in the kernel. */
+	smp_store_release(producer_pos_ptr, producer_pos + BPF_RINGBUF_HDR_SZ);
+
+	drain_current_samples();
+	ASSERT_EQ(skel->bss->read, 0, "num_samples_after_bad_sample");
+	ASSERT_EQ(skel->bss->err, err, "err_after_bad_sample");
+
+	ASSERT_OK(munmap(producer_pos_ptr, page_size), "unmap_producer_pos");
+	ASSERT_OK(munmap(data_ptr, page_size), "unmap_data_ptr");
+}
+
+static void test_user_ringbuf_post_misaligned(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err;
+	__u32 size = (1 << 5) + 7;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (!ASSERT_OK(err, "misaligned_skel"))
+		return;
+
+	manually_write_test_invalid_sample(skel, size, size, -EINVAL);
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_post_producer_wrong_offset(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err;
+	__u32 size = (1 << 5);
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (!ASSERT_OK(err, "wrong_offset_skel"))
+		return;
+
+	manually_write_test_invalid_sample(skel, size, size - 8, -EINVAL);
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_post_larger_than_ringbuf_sz(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err;
+	__u32 size = c_ringbuf_size;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (!ASSERT_OK(err, "huge_sample_skel"))
+		return;
+
+	manually_write_test_invalid_sample(skel, size, size, -E2BIG);
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_basic(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (!ASSERT_OK(err, "ringbuf_basic_skel"))
+		return;
+
+	ASSERT_EQ(skel->bss->read, 0, "num_samples_read_before");
+
+	err = write_samples(ringbuf, 2);
+	if (!ASSERT_OK(err, "write_samples"))
+		goto cleanup;
+
+	ASSERT_EQ(skel->bss->read, 2, "num_samples_read_after");
+
+cleanup:
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_sample_full_ring_buffer(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err;
+	void *sample;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (!ASSERT_OK(err, "ringbuf_full_sample_skel"))
+		return;
+
+	sample = user_ring_buffer__reserve(ringbuf, c_ringbuf_size - BPF_RINGBUF_HDR_SZ);
+	if (!ASSERT_OK_PTR(sample, "full_sample"))
+		goto cleanup;
+
+	user_ring_buffer__submit(ringbuf, sample);
+	ASSERT_EQ(skel->bss->read, 0, "num_samples_read_before");
+	drain_current_samples();
+	ASSERT_EQ(skel->bss->read, 1, "num_samples_read_after");
+
+cleanup:
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_post_alignment_autoadjust(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	struct sample *sample;
+	int err;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (!ASSERT_OK(err, "ringbuf_align_autoadjust_skel"))
+		return;
+
+	/* libbpf should automatically round any sample up to an 8-byte alignment. */
+	sample = user_ring_buffer__reserve(ringbuf, sizeof(*sample) + 1);
+	ASSERT_OK_PTR(sample, "reserve_autoaligned");
+	user_ring_buffer__submit(ringbuf, sample);
+
+	ASSERT_EQ(skel->bss->read, 0, "num_samples_read_before");
+	drain_current_samples();
+	ASSERT_EQ(skel->bss->read, 1, "num_samples_read_after");
+
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_overfill(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (err)
+		return;
+
+	err = write_samples(ringbuf, c_max_entries * 5);
+	ASSERT_ERR(err, "write_samples");
+	ASSERT_EQ(skel->bss->read, c_max_entries, "max_entries");
+
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_discards_properly_ignored(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err, num_discarded = 0;
+	__u64 *token;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (err)
+		return;
+
+	ASSERT_EQ(skel->bss->read, 0, "num_samples_read_before");
+
+	while (1) {
+		/* Write samples until the buffer is full. */
+		token = user_ring_buffer__reserve(ringbuf, sizeof(*token));
+		if (!token)
+			break;
+
+		user_ring_buffer__discard(ringbuf, token);
+		num_discarded++;
+	}
+
+	if (!ASSERT_GE(num_discarded, 0, "num_discarded"))
+		goto cleanup;
+
+	/* Should not read any samples, as they are all discarded. */
+	ASSERT_EQ(skel->bss->read, 0, "num_pre_kick");
+	drain_current_samples();
+	ASSERT_EQ(skel->bss->read, 0, "num_post_kick");
+
+	/* Now that the ring buffer has been drained, we should be able to
+	 * reserve another token.
+	 */
+	token = user_ring_buffer__reserve(ringbuf, sizeof(*token));
+
+	if (!ASSERT_OK_PTR(token, "new_token"))
+		goto cleanup;
+
+	user_ring_buffer__discard(ringbuf, token);
+cleanup:
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void test_user_ringbuf_loop(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	uint32_t total_samples = 8192;
+	uint32_t remaining_samples = total_samples;
+	int err;
+
+	BUILD_BUG_ON(total_samples <= c_max_entries);
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (err)
+		return;
+
+	do  {
+		uint32_t curr_samples;
+
+		curr_samples = remaining_samples > c_max_entries
+			? c_max_entries : remaining_samples;
+		err = write_samples(ringbuf, curr_samples);
+		if (err != 0) {
+			/* Assert inside of if statement to avoid flooding logs
+			 * on the success path.
+			 */
+			ASSERT_OK(err, "write_samples");
+			goto cleanup;
+		}
+
+		remaining_samples -= curr_samples;
+		ASSERT_EQ(skel->bss->read, total_samples - remaining_samples,
+			  "current_batched_entries");
+	} while (remaining_samples > 0);
+	ASSERT_EQ(skel->bss->read, total_samples, "total_batched_entries");
+
+cleanup:
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static int send_test_message(struct user_ring_buffer *ringbuf,
+			     enum test_msg_op op, s64 operand_64,
+			     s32 operand_32)
+{
+	struct test_msg *msg;
+
+	msg = user_ring_buffer__reserve(ringbuf, sizeof(*msg));
+	if (!msg) {
+		/* Assert on the error path to avoid spamming logs with mostly
+		 * success messages.
+		 */
+		ASSERT_OK_PTR(msg, "reserve_msg");
+		return -ENOMEM;
+	}
+
+	msg->msg_op = op;
+
+	switch (op) {
+	case TEST_MSG_OP_INC64:
+	case TEST_MSG_OP_MUL64:
+		msg->operand_64 = operand_64;
+		break;
+	case TEST_MSG_OP_INC32:
+	case TEST_MSG_OP_MUL32:
+		msg->operand_32 = operand_32;
+		break;
+	default:
+		PRINT_FAIL("Invalid operand %d\n", op);
+		user_ring_buffer__discard(ringbuf, msg);
+		return -EINVAL;
+	}
+
+	user_ring_buffer__submit(ringbuf, msg);
+
+	return 0;
+}
+
+static void kick_kernel_read_messages(void)
+{
+	syscall(__NR_prctl);
+}
+
+static int handle_kernel_msg(void *ctx, void *data, size_t len)
+{
+	struct user_ringbuf_success *skel = ctx;
+	struct test_msg *msg = data;
+
+	switch (msg->msg_op) {
+	case TEST_MSG_OP_INC64:
+		skel->bss->user_mutated += msg->operand_64;
+		return 0;
+	case TEST_MSG_OP_INC32:
+		skel->bss->user_mutated += msg->operand_32;
+		return 0;
+	case TEST_MSG_OP_MUL64:
+		skel->bss->user_mutated *= msg->operand_64;
+		return 0;
+	case TEST_MSG_OP_MUL32:
+		skel->bss->user_mutated *= msg->operand_32;
+		return 0;
+	default:
+		fprintf(stderr, "Invalid operand %d\n", msg->msg_op);
+		return -EINVAL;
+	}
+}
+
+static void drain_kernel_messages_buffer(struct ring_buffer *kern_ringbuf,
+					 struct user_ringbuf_success *skel)
+{
+	int cnt;
+
+	cnt = ring_buffer__consume(kern_ringbuf);
+	ASSERT_EQ(cnt, 8, "consume_kern_ringbuf");
+	ASSERT_OK(skel->bss->err, "consume_kern_ringbuf_err");
+}
+
+static void test_user_ringbuf_msg_protocol(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *user_ringbuf;
+	struct ring_buffer *kern_ringbuf;
+	int err, i;
+	__u64 expected_kern = 0;
+
+	err = load_skel_create_ringbufs(&skel, &kern_ringbuf, handle_kernel_msg, &user_ringbuf);
+	if (!ASSERT_OK(err, "create_ringbufs"))
+		return;
+
+	for (i = 0; i < 64; i++) {
+		enum test_msg_op op = i % TEST_MSG_OP_NUM_OPS;
+		__u64 operand_64 = TEST_OP_64;
+		__u32 operand_32 = TEST_OP_32;
+
+		err = send_test_message(user_ringbuf, op, operand_64, operand_32);
+		if (err) {
+			/* Only assert on a failure to avoid spamming success logs. */
+			ASSERT_OK(err, "send_test_message");
+			goto cleanup;
+		}
+
+		switch (op) {
+		case TEST_MSG_OP_INC64:
+			expected_kern += operand_64;
+			break;
+		case TEST_MSG_OP_INC32:
+			expected_kern += operand_32;
+			break;
+		case TEST_MSG_OP_MUL64:
+			expected_kern *= operand_64;
+			break;
+		case TEST_MSG_OP_MUL32:
+			expected_kern *= operand_32;
+			break;
+		default:
+			PRINT_FAIL("Unexpected op %d\n", op);
+			goto cleanup;
+		}
+
+		if (i % 8 == 0) {
+			kick_kernel_read_messages();
+			ASSERT_EQ(skel->bss->kern_mutated, expected_kern, "expected_kern");
+			ASSERT_EQ(skel->bss->err, 0, "bpf_prog_err");
+			drain_kernel_messages_buffer(kern_ringbuf, skel);
+		}
+	}
+
+cleanup:
+	ring_buffer__free(kern_ringbuf);
+	user_ring_buffer__free(user_ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+static void *kick_kernel_cb(void *arg)
+{
+	/* Kick the kernel, causing it to drain the ring buffer and then wake
+	 * up the test thread waiting on epoll.
+	 */
+	syscall(__NR_getrlimit);
+
+	return NULL;
+}
+
+static int spawn_kick_thread_for_poll(void)
+{
+	pthread_t thread;
+
+	return pthread_create(&thread, NULL, kick_kernel_cb, NULL);
+}
+
+static void test_user_ringbuf_blocking_reserve(void)
+{
+	struct user_ringbuf_success *skel;
+	struct user_ring_buffer *ringbuf;
+	int err, num_written = 0;
+	__u64 *token;
+
+	err = load_skel_create_user_ringbuf(&skel, &ringbuf);
+	if (err)
+		return;
+
+	ASSERT_EQ(skel->bss->read, 0, "num_samples_read_before");
+
+	while (1) {
+		/* Write samples until the buffer is full. */
+		token = user_ring_buffer__reserve(ringbuf, sizeof(*token));
+		if (!token)
+			break;
+
+		*token = 0xdeadbeef;
+
+		user_ring_buffer__submit(ringbuf, token);
+		num_written++;
+	}
+
+	if (!ASSERT_GE(num_written, 0, "num_written"))
+		goto cleanup;
+
+	/* Should not have read any samples until the kernel is kicked. */
+	ASSERT_EQ(skel->bss->read, 0, "num_pre_kick");
+
+	/* We correctly time out after 1 second, without a sample. */
+	token = user_ring_buffer__reserve_blocking(ringbuf, sizeof(*token), 1000);
+	if (!ASSERT_EQ(token, NULL, "pre_kick_timeout_token"))
+		goto cleanup;
+
+	err = spawn_kick_thread_for_poll();
+	if (!ASSERT_EQ(err, 0, "deferred_kick_thread\n"))
+		goto cleanup;
+
+	/* After spawning another thread that asychronously kicks the kernel to
+	 * drain the messages, we're able to block and successfully get a
+	 * sample once we receive an event notification.
+	 */
+	token = user_ring_buffer__reserve_blocking(ringbuf, sizeof(*token), 10000);
+
+	if (!ASSERT_OK_PTR(token, "block_token"))
+		goto cleanup;
+
+	ASSERT_GT(skel->bss->read, 0, "num_post_kill");
+	ASSERT_LE(skel->bss->read, num_written, "num_post_kill");
+	ASSERT_EQ(skel->bss->err, 0, "err_post_poll");
+	user_ring_buffer__discard(ringbuf, token);
+
+cleanup:
+	user_ring_buffer__free(ringbuf);
+	user_ringbuf_success__destroy(skel);
+}
+
+#define SUCCESS_TEST(_func) { _func, #_func }
+
+static struct {
+	void (*test_callback)(void);
+	const char *test_name;
+} success_tests[] = {
+	SUCCESS_TEST(test_user_ringbuf_mappings),
+	SUCCESS_TEST(test_user_ringbuf_post_misaligned),
+	SUCCESS_TEST(test_user_ringbuf_post_producer_wrong_offset),
+	SUCCESS_TEST(test_user_ringbuf_post_larger_than_ringbuf_sz),
+	SUCCESS_TEST(test_user_ringbuf_basic),
+	SUCCESS_TEST(test_user_ringbuf_sample_full_ring_buffer),
+	SUCCESS_TEST(test_user_ringbuf_post_alignment_autoadjust),
+	SUCCESS_TEST(test_user_ringbuf_overfill),
+	SUCCESS_TEST(test_user_ringbuf_discards_properly_ignored),
+	SUCCESS_TEST(test_user_ringbuf_loop),
+	SUCCESS_TEST(test_user_ringbuf_msg_protocol),
+	SUCCESS_TEST(test_user_ringbuf_blocking_reserve),
+};
+
+void test_user_ringbuf(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(success_tests); i++) {
+		if (!test__start_subtest(success_tests[i].test_name))
+			continue;
+
+		success_tests[i].test_callback();
+	}
+
+	RUN_TESTS(user_ringbuf_fail);
+}