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, 726 insertions, 0 deletions

diff --git a/mm/page_owner.c b/mm/page_owner.c
new file mode 100644
index 000000000..2d27f532d
--- /dev/null
+++ b/mm/page_owner.c
@@ -0,0 +1,726 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/debugfs.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/memblock.h>
+#include <linux/stacktrace.h>
+#include <linux/page_owner.h>
+#include <linux/jump_label.h>
+#include <linux/migrate.h>
+#include <linux/stackdepot.h>
+#include <linux/seq_file.h>
+#include <linux/memcontrol.h>
+#include <linux/sched/clock.h>
+
+#include "internal.h"
+
+/*
+ * TODO: teach PAGE_OWNER_STACK_DEPTH (__dump_page_owner and save_stack)
+ * to use off stack temporal storage
+ */
+#define PAGE_OWNER_STACK_DEPTH (16)
+
+struct page_owner {
+	unsigned short order;
+	short last_migrate_reason;
+	gfp_t gfp_mask;
+	depot_stack_handle_t handle;
+	depot_stack_handle_t free_handle;
+	u64 ts_nsec;
+	u64 free_ts_nsec;
+	char comm[TASK_COMM_LEN];
+	pid_t pid;
+	pid_t tgid;
+};
+
+static bool page_owner_enabled __initdata;
+DEFINE_STATIC_KEY_FALSE(page_owner_inited);
+
+static depot_stack_handle_t dummy_handle;
+static depot_stack_handle_t failure_handle;
+static depot_stack_handle_t early_handle;
+
+static void init_early_allocated_pages(void);
+
+static int __init early_page_owner_param(char *buf)
+{
+	int ret = kstrtobool(buf, &page_owner_enabled);
+
+	if (page_owner_enabled)
+		stack_depot_want_early_init();
+
+	return ret;
+}
+early_param("page_owner", early_page_owner_param);
+
+static __init bool need_page_owner(void)
+{
+	return page_owner_enabled;
+}
+
+static __always_inline depot_stack_handle_t create_dummy_stack(void)
+{
+	unsigned long entries[4];
+	unsigned int nr_entries;
+
+	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
+	return stack_depot_save(entries, nr_entries, GFP_KERNEL);
+}
+
+static noinline void register_dummy_stack(void)
+{
+	dummy_handle = create_dummy_stack();
+}
+
+static noinline void register_failure_stack(void)
+{
+	failure_handle = create_dummy_stack();
+}
+
+static noinline void register_early_stack(void)
+{
+	early_handle = create_dummy_stack();
+}
+
+static __init void init_page_owner(void)
+{
+	if (!page_owner_enabled)
+		return;
+
+	register_dummy_stack();
+	register_failure_stack();
+	register_early_stack();
+	static_branch_enable(&page_owner_inited);
+	init_early_allocated_pages();
+}
+
+struct page_ext_operations page_owner_ops = {
+	.size = sizeof(struct page_owner),
+	.need = need_page_owner,
+	.init = init_page_owner,
+};
+
+static inline struct page_owner *get_page_owner(struct page_ext *page_ext)
+{
+	return (void *)page_ext + page_owner_ops.offset;
+}
+
+static noinline depot_stack_handle_t save_stack(gfp_t flags)
+{
+	unsigned long entries[PAGE_OWNER_STACK_DEPTH];
+	depot_stack_handle_t handle;
+	unsigned int nr_entries;
+
+	/*
+	 * Avoid recursion.
+	 *
+	 * Sometimes page metadata allocation tracking requires more
+	 * memory to be allocated:
+	 * - when new stack trace is saved to stack depot
+	 * - when backtrace itself is calculated (ia64)
+	 */
+	if (current->in_page_owner)
+		return dummy_handle;
+	current->in_page_owner = 1;
+
+	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2);
+	handle = stack_depot_save(entries, nr_entries, flags);
+	if (!handle)
+		handle = failure_handle;
+
+	current->in_page_owner = 0;
+	return handle;
+}
+
+void __reset_page_owner(struct page *page, unsigned short order)
+{
+	int i;
+	struct page_ext *page_ext;
+	depot_stack_handle_t handle;
+	struct page_owner *page_owner;
+	u64 free_ts_nsec = local_clock();
+
+	page_ext = page_ext_get(page);
+	if (unlikely(!page_ext))
+		return;
+
+	handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
+	for (i = 0; i < (1 << order); i++) {
+		__clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
+		page_owner = get_page_owner(page_ext);
+		page_owner->free_handle = handle;
+		page_owner->free_ts_nsec = free_ts_nsec;
+		page_ext = page_ext_next(page_ext);
+	}
+	page_ext_put(page_ext);
+}
+
+static inline void __set_page_owner_handle(struct page_ext *page_ext,
+					depot_stack_handle_t handle,
+					unsigned short order, gfp_t gfp_mask)
+{
+	struct page_owner *page_owner;
+	int i;
+
+	for (i = 0; i < (1 << order); i++) {
+		page_owner = get_page_owner(page_ext);
+		page_owner->handle = handle;
+		page_owner->order = order;
+		page_owner->gfp_mask = gfp_mask;
+		page_owner->last_migrate_reason = -1;
+		page_owner->pid = current->pid;
+		page_owner->tgid = current->tgid;
+		page_owner->ts_nsec = local_clock();
+		strscpy(page_owner->comm, current->comm,
+			sizeof(page_owner->comm));
+		__set_bit(PAGE_EXT_OWNER, &page_ext->flags);
+		__set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
+
+		page_ext = page_ext_next(page_ext);
+	}
+}
+
+noinline void __set_page_owner(struct page *page, unsigned short order,
+					gfp_t gfp_mask)
+{
+	struct page_ext *page_ext;
+	depot_stack_handle_t handle;
+
+	handle = save_stack(gfp_mask);
+
+	page_ext = page_ext_get(page);
+	if (unlikely(!page_ext))
+		return;
+	__set_page_owner_handle(page_ext, handle, order, gfp_mask);
+	page_ext_put(page_ext);
+}
+
+void __set_page_owner_migrate_reason(struct page *page, int reason)
+{
+	struct page_ext *page_ext = page_ext_get(page);
+	struct page_owner *page_owner;
+
+	if (unlikely(!page_ext))
+		return;
+
+	page_owner = get_page_owner(page_ext);
+	page_owner->last_migrate_reason = reason;
+	page_ext_put(page_ext);
+}
+
+void __split_page_owner(struct page *page, unsigned int nr)
+{
+	int i;
+	struct page_ext *page_ext = page_ext_get(page);
+	struct page_owner *page_owner;
+
+	if (unlikely(!page_ext))
+		return;
+
+	for (i = 0; i < nr; i++) {
+		page_owner = get_page_owner(page_ext);
+		page_owner->order = 0;
+		page_ext = page_ext_next(page_ext);
+	}
+	page_ext_put(page_ext);
+}
+
+void __folio_copy_owner(struct folio *newfolio, struct folio *old)
+{
+	struct page_ext *old_ext;
+	struct page_ext *new_ext;
+	struct page_owner *old_page_owner, *new_page_owner;
+
+	old_ext = page_ext_get(&old->page);
+	if (unlikely(!old_ext))
+		return;
+
+	new_ext = page_ext_get(&newfolio->page);
+	if (unlikely(!new_ext)) {
+		page_ext_put(old_ext);
+		return;
+	}
+
+	old_page_owner = get_page_owner(old_ext);
+	new_page_owner = get_page_owner(new_ext);
+	new_page_owner->order = old_page_owner->order;
+	new_page_owner->gfp_mask = old_page_owner->gfp_mask;
+	new_page_owner->last_migrate_reason =
+		old_page_owner->last_migrate_reason;
+	new_page_owner->handle = old_page_owner->handle;
+	new_page_owner->pid = old_page_owner->pid;
+	new_page_owner->tgid = old_page_owner->tgid;
+	new_page_owner->ts_nsec = old_page_owner->ts_nsec;
+	new_page_owner->free_ts_nsec = old_page_owner->ts_nsec;
+	strcpy(new_page_owner->comm, old_page_owner->comm);
+
+	/*
+	 * We don't clear the bit on the old folio as it's going to be freed
+	 * after migration. Until then, the info can be useful in case of
+	 * a bug, and the overall stats will be off a bit only temporarily.
+	 * Also, migrate_misplaced_transhuge_page() can still fail the
+	 * migration and then we want the old folio to retain the info. But
+	 * in that case we also don't need to explicitly clear the info from
+	 * the new page, which will be freed.
+	 */
+	__set_bit(PAGE_EXT_OWNER, &new_ext->flags);
+	__set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags);
+	page_ext_put(new_ext);
+	page_ext_put(old_ext);
+}
+
+void pagetypeinfo_showmixedcount_print(struct seq_file *m,
+				       pg_data_t *pgdat, struct zone *zone)
+{
+	struct page *page;
+	struct page_ext *page_ext;
+	struct page_owner *page_owner;
+	unsigned long pfn, block_end_pfn;
+	unsigned long end_pfn = zone_end_pfn(zone);
+	unsigned long count[MIGRATE_TYPES] = { 0, };
+	int pageblock_mt, page_mt;
+	int i;
+
+	/* Scan block by block. First and last block may be incomplete */
+	pfn = zone->zone_start_pfn;
+
+	/*
+	 * Walk the zone in pageblock_nr_pages steps. If a page block spans
+	 * a zone boundary, it will be double counted between zones. This does
+	 * not matter as the mixed block count will still be correct
+	 */
+	for (; pfn < end_pfn; ) {
+		page = pfn_to_online_page(pfn);
+		if (!page) {
+			pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
+			continue;
+		}
+
+		block_end_pfn = pageblock_end_pfn(pfn);
+		block_end_pfn = min(block_end_pfn, end_pfn);
+
+		pageblock_mt = get_pageblock_migratetype(page);
+
+		for (; pfn < block_end_pfn; pfn++) {
+			/* The pageblock is online, no need to recheck. */
+			page = pfn_to_page(pfn);
+
+			if (page_zone(page) != zone)
+				continue;
+
+			if (PageBuddy(page)) {
+				unsigned long freepage_order;
+
+				freepage_order = buddy_order_unsafe(page);
+				if (freepage_order < MAX_ORDER)
+					pfn += (1UL << freepage_order) - 1;
+				continue;
+			}
+
+			if (PageReserved(page))
+				continue;
+
+			page_ext = page_ext_get(page);
+			if (unlikely(!page_ext))
+				continue;
+
+			if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
+				goto ext_put_continue;
+
+			page_owner = get_page_owner(page_ext);
+			page_mt = gfp_migratetype(page_owner->gfp_mask);
+			if (pageblock_mt != page_mt) {
+				if (is_migrate_cma(pageblock_mt))
+					count[MIGRATE_MOVABLE]++;
+				else
+					count[pageblock_mt]++;
+
+				pfn = block_end_pfn;
+				page_ext_put(page_ext);
+				break;
+			}
+			pfn += (1UL << page_owner->order) - 1;
+ext_put_continue:
+			page_ext_put(page_ext);
+		}
+	}
+
+	/* Print counts */
+	seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
+	for (i = 0; i < MIGRATE_TYPES; i++)
+		seq_printf(m, "%12lu ", count[i]);
+	seq_putc(m, '\n');
+}
+
+/*
+ * Looking for memcg information and print it out
+ */
+static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret,
+					 struct page *page)
+{
+#ifdef CONFIG_MEMCG
+	unsigned long memcg_data;
+	struct mem_cgroup *memcg;
+	bool online;
+	char name[80];
+
+	rcu_read_lock();
+	memcg_data = READ_ONCE(page->memcg_data);
+	if (!memcg_data)
+		goto out_unlock;
+
+	if (memcg_data & MEMCG_DATA_OBJCGS)
+		ret += scnprintf(kbuf + ret, count - ret,
+				"Slab cache page\n");
+
+	memcg = page_memcg_check(page);
+	if (!memcg)
+		goto out_unlock;
+
+	online = (memcg->css.flags & CSS_ONLINE);
+	cgroup_name(memcg->css.cgroup, name, sizeof(name));
+	ret += scnprintf(kbuf + ret, count - ret,
+			"Charged %sto %smemcg %s\n",
+			PageMemcgKmem(page) ? "(via objcg) " : "",
+			online ? "" : "offline ",
+			name);
+out_unlock:
+	rcu_read_unlock();
+#endif /* CONFIG_MEMCG */
+
+	return ret;
+}
+
+static ssize_t
+print_page_owner(char __user *buf, size_t count, unsigned long pfn,
+		struct page *page, struct page_owner *page_owner,
+		depot_stack_handle_t handle)
+{
+	int ret, pageblock_mt, page_mt;
+	char *kbuf;
+
+	count = min_t(size_t, count, PAGE_SIZE);
+	kbuf = kmalloc(count, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	ret = scnprintf(kbuf, count,
+			"Page allocated via order %u, mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu ns, free_ts %llu ns\n",
+			page_owner->order, page_owner->gfp_mask,
+			&page_owner->gfp_mask, page_owner->pid,
+			page_owner->tgid, page_owner->comm,
+			page_owner->ts_nsec, page_owner->free_ts_nsec);
+
+	/* Print information relevant to grouping pages by mobility */
+	pageblock_mt = get_pageblock_migratetype(page);
+	page_mt  = gfp_migratetype(page_owner->gfp_mask);
+	ret += scnprintf(kbuf + ret, count - ret,
+			"PFN %lu type %s Block %lu type %s Flags %pGp\n",
+			pfn,
+			migratetype_names[page_mt],
+			pfn >> pageblock_order,
+			migratetype_names[pageblock_mt],
+			&page->flags);
+
+	ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0);
+	if (ret >= count)
+		goto err;
+
+	if (page_owner->last_migrate_reason != -1) {
+		ret += scnprintf(kbuf + ret, count - ret,
+			"Page has been migrated, last migrate reason: %s\n",
+			migrate_reason_names[page_owner->last_migrate_reason]);
+	}
+
+	ret = print_page_owner_memcg(kbuf, count, ret, page);
+
+	ret += snprintf(kbuf + ret, count - ret, "\n");
+	if (ret >= count)
+		goto err;
+
+	if (copy_to_user(buf, kbuf, ret))
+		ret = -EFAULT;
+
+	kfree(kbuf);
+	return ret;
+
+err:
+	kfree(kbuf);
+	return -ENOMEM;
+}
+
+void __dump_page_owner(const struct page *page)
+{
+	struct page_ext *page_ext = page_ext_get((void *)page);
+	struct page_owner *page_owner;
+	depot_stack_handle_t handle;
+	gfp_t gfp_mask;
+	int mt;
+
+	if (unlikely(!page_ext)) {
+		pr_alert("There is not page extension available.\n");
+		return;
+	}
+
+	page_owner = get_page_owner(page_ext);
+	gfp_mask = page_owner->gfp_mask;
+	mt = gfp_migratetype(gfp_mask);
+
+	if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) {
+		pr_alert("page_owner info is not present (never set?)\n");
+		page_ext_put(page_ext);
+		return;
+	}
+
+	if (test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
+		pr_alert("page_owner tracks the page as allocated\n");
+	else
+		pr_alert("page_owner tracks the page as freed\n");
+
+	pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu, free_ts %llu\n",
+		 page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask,
+		 page_owner->pid, page_owner->tgid, page_owner->comm,
+		 page_owner->ts_nsec, page_owner->free_ts_nsec);
+
+	handle = READ_ONCE(page_owner->handle);
+	if (!handle)
+		pr_alert("page_owner allocation stack trace missing\n");
+	else
+		stack_depot_print(handle);
+
+	handle = READ_ONCE(page_owner->free_handle);
+	if (!handle) {
+		pr_alert("page_owner free stack trace missing\n");
+	} else {
+		pr_alert("page last free stack trace:\n");
+		stack_depot_print(handle);
+	}
+
+	if (page_owner->last_migrate_reason != -1)
+		pr_alert("page has been migrated, last migrate reason: %s\n",
+			migrate_reason_names[page_owner->last_migrate_reason]);
+	page_ext_put(page_ext);
+}
+
+static ssize_t
+read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	unsigned long pfn;
+	struct page *page;
+	struct page_ext *page_ext;
+	struct page_owner *page_owner;
+	depot_stack_handle_t handle;
+
+	if (!static_branch_unlikely(&page_owner_inited))
+		return -EINVAL;
+
+	page = NULL;
+	if (*ppos == 0)
+		pfn = min_low_pfn;
+	else
+		pfn = *ppos;
+	/* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */
+	while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0)
+		pfn++;
+
+	/* Find an allocated page */
+	for (; pfn < max_pfn; pfn++) {
+		/*
+		 * This temporary page_owner is required so
+		 * that we can avoid the context switches while holding
+		 * the rcu lock and copying the page owner information to
+		 * user through copy_to_user() or GFP_KERNEL allocations.
+		 */
+		struct page_owner page_owner_tmp;
+
+		/*
+		 * If the new page is in a new MAX_ORDER_NR_PAGES area,
+		 * validate the area as existing, skip it if not
+		 */
+		if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) {
+			pfn += MAX_ORDER_NR_PAGES - 1;
+			continue;
+		}
+
+		page = pfn_to_page(pfn);
+		if (PageBuddy(page)) {
+			unsigned long freepage_order = buddy_order_unsafe(page);
+
+			if (freepage_order < MAX_ORDER)
+				pfn += (1UL << freepage_order) - 1;
+			continue;
+		}
+
+		page_ext = page_ext_get(page);
+		if (unlikely(!page_ext))
+			continue;
+
+		/*
+		 * Some pages could be missed by concurrent allocation or free,
+		 * because we don't hold the zone lock.
+		 */
+		if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
+			goto ext_put_continue;
+
+		/*
+		 * Although we do have the info about past allocation of free
+		 * pages, it's not relevant for current memory usage.
+		 */
+		if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
+			goto ext_put_continue;
+
+		page_owner = get_page_owner(page_ext);
+
+		/*
+		 * Don't print "tail" pages of high-order allocations as that
+		 * would inflate the stats.
+		 */
+		if (!IS_ALIGNED(pfn, 1 << page_owner->order))
+			goto ext_put_continue;
+
+		/*
+		 * Access to page_ext->handle isn't synchronous so we should
+		 * be careful to access it.
+		 */
+		handle = READ_ONCE(page_owner->handle);
+		if (!handle)
+			goto ext_put_continue;
+
+		/* Record the next PFN to read in the file offset */
+		*ppos = pfn + 1;
+
+		page_owner_tmp = *page_owner;
+		page_ext_put(page_ext);
+		return print_page_owner(buf, count, pfn, page,
+				&page_owner_tmp, handle);
+ext_put_continue:
+		page_ext_put(page_ext);
+	}
+
+	return 0;
+}
+
+static loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
+{
+	switch (orig) {
+	case SEEK_SET:
+		file->f_pos = offset;
+		break;
+	case SEEK_CUR:
+		file->f_pos += offset;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return file->f_pos;
+}
+
+static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
+{
+	unsigned long pfn = zone->zone_start_pfn;
+	unsigned long end_pfn = zone_end_pfn(zone);
+	unsigned long count = 0;
+
+	/*
+	 * Walk the zone in pageblock_nr_pages steps. If a page block spans
+	 * a zone boundary, it will be double counted between zones. This does
+	 * not matter as the mixed block count will still be correct
+	 */
+	for (; pfn < end_pfn; ) {
+		unsigned long block_end_pfn;
+
+		if (!pfn_valid(pfn)) {
+			pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
+			continue;
+		}
+
+		block_end_pfn = pageblock_end_pfn(pfn);
+		block_end_pfn = min(block_end_pfn, end_pfn);
+
+		for (; pfn < block_end_pfn; pfn++) {
+			struct page *page = pfn_to_page(pfn);
+			struct page_ext *page_ext;
+
+			if (page_zone(page) != zone)
+				continue;
+
+			/*
+			 * To avoid having to grab zone->lock, be a little
+			 * careful when reading buddy page order. The only
+			 * danger is that we skip too much and potentially miss
+			 * some early allocated pages, which is better than
+			 * heavy lock contention.
+			 */
+			if (PageBuddy(page)) {
+				unsigned long order = buddy_order_unsafe(page);
+
+				if (order > 0 && order < MAX_ORDER)
+					pfn += (1UL << order) - 1;
+				continue;
+			}
+
+			if (PageReserved(page))
+				continue;
+
+			page_ext = page_ext_get(page);
+			if (unlikely(!page_ext))
+				continue;
+
+			/* Maybe overlapping zone */
+			if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
+				goto ext_put_continue;
+
+			/* Found early allocated page */
+			__set_page_owner_handle(page_ext, early_handle,
+						0, 0);
+			count++;
+ext_put_continue:
+			page_ext_put(page_ext);
+		}
+		cond_resched();
+	}
+
+	pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n",
+		pgdat->node_id, zone->name, count);
+}
+
+static void init_zones_in_node(pg_data_t *pgdat)
+{
+	struct zone *zone;
+	struct zone *node_zones = pgdat->node_zones;
+
+	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
+		if (!populated_zone(zone))
+			continue;
+
+		init_pages_in_zone(pgdat, zone);
+	}
+}
+
+static void init_early_allocated_pages(void)
+{
+	pg_data_t *pgdat;
+
+	for_each_online_pgdat(pgdat)
+		init_zones_in_node(pgdat);
+}
+
+static const struct file_operations proc_page_owner_operations = {
+	.read		= read_page_owner,
+	.llseek		= lseek_page_owner,
+};
+
+static int __init pageowner_init(void)
+{
+	if (!static_branch_unlikely(&page_owner_inited)) {
+		pr_info("page_owner is disabled\n");
+		return 0;
+	}
+
+	debugfs_create_file("page_owner", 0400, NULL, NULL,
+			    &proc_page_owner_operations);
+
+	return 0;
+}
+late_initcall(pageowner_init)