Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

3 files changed, 1084 insertions, 0 deletions

diff --git a/net/switchdev/Kconfig b/net/switchdev/Kconfig
new file mode 100644
index 000000000..18a2d980e
--- /dev/null
+++ b/net/switchdev/Kconfig
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Configuration for Switch device support
+#
+
+config NET_SWITCHDEV
+	bool "Switch (and switch-ish) device support"
+	depends on INET
+	help
+	  This module provides glue between core networking code and device
+	  drivers in order to support hardware switch chips in very generic
+	  meaning of the word "switch". This include devices supporting L2/L3 but
+	  also various flow offloading chips, including switches embedded into
+	  SR-IOV NICs.
diff --git a/net/switchdev/Makefile b/net/switchdev/Makefile
new file mode 100644
index 000000000..c5561d7f3
--- /dev/null
+++ b/net/switchdev/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Switch device API
+#
+
+obj-y += switchdev.o
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
new file mode 100644
index 000000000..474df25e9
--- /dev/null
+++ b/net/switchdev/switchdev.c
@@ -0,0 +1,1064 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/switchdev/switchdev.c - Switch device API
+ * Copyright (c) 2014-2015 Jiri Pirko <jiri@resnulli.us>
+ * Copyright (c) 2014-2015 Scott Feldman <sfeldma@gmail.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/if_bridge.h>
+#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/if_vlan.h>
+#include <linux/rtnetlink.h>
+#include <net/switchdev.h>
+
+static bool switchdev_obj_eq(const struct switchdev_obj *a,
+			     const struct switchdev_obj *b)
+{
+	const struct switchdev_obj_port_vlan *va, *vb;
+	const struct switchdev_obj_port_mdb *ma, *mb;
+
+	if (a->id != b->id || a->orig_dev != b->orig_dev)
+		return false;
+
+	switch (a->id) {
+	case SWITCHDEV_OBJ_ID_PORT_VLAN:
+		va = SWITCHDEV_OBJ_PORT_VLAN(a);
+		vb = SWITCHDEV_OBJ_PORT_VLAN(b);
+		return va->flags == vb->flags &&
+			va->vid == vb->vid &&
+			va->changed == vb->changed;
+	case SWITCHDEV_OBJ_ID_PORT_MDB:
+	case SWITCHDEV_OBJ_ID_HOST_MDB:
+		ma = SWITCHDEV_OBJ_PORT_MDB(a);
+		mb = SWITCHDEV_OBJ_PORT_MDB(b);
+		return ma->vid == mb->vid &&
+			ether_addr_equal(ma->addr, mb->addr);
+	default:
+		break;
+	}
+
+	BUG();
+}
+
+static LIST_HEAD(deferred);
+static DEFINE_SPINLOCK(deferred_lock);
+
+typedef void switchdev_deferred_func_t(struct net_device *dev,
+				       const void *data);
+
+struct switchdev_deferred_item {
+	struct list_head list;
+	struct net_device *dev;
+	netdevice_tracker dev_tracker;
+	switchdev_deferred_func_t *func;
+	unsigned long data[];
+};
+
+static struct switchdev_deferred_item *switchdev_deferred_dequeue(void)
+{
+	struct switchdev_deferred_item *dfitem;
+
+	spin_lock_bh(&deferred_lock);
+	if (list_empty(&deferred)) {
+		dfitem = NULL;
+		goto unlock;
+	}
+	dfitem = list_first_entry(&deferred,
+				  struct switchdev_deferred_item, list);
+	list_del(&dfitem->list);
+unlock:
+	spin_unlock_bh(&deferred_lock);
+	return dfitem;
+}
+
+/**
+ *	switchdev_deferred_process - Process ops in deferred queue
+ *
+ *	Called to flush the ops currently queued in deferred ops queue.
+ *	rtnl_lock must be held.
+ */
+void switchdev_deferred_process(void)
+{
+	struct switchdev_deferred_item *dfitem;
+
+	ASSERT_RTNL();
+
+	while ((dfitem = switchdev_deferred_dequeue())) {
+		dfitem->func(dfitem->dev, dfitem->data);
+		netdev_put(dfitem->dev, &dfitem->dev_tracker);
+		kfree(dfitem);
+	}
+}
+EXPORT_SYMBOL_GPL(switchdev_deferred_process);
+
+static void switchdev_deferred_process_work(struct work_struct *work)
+{
+	rtnl_lock();
+	switchdev_deferred_process();
+	rtnl_unlock();
+}
+
+static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);
+
+static int switchdev_deferred_enqueue(struct net_device *dev,
+				      const void *data, size_t data_len,
+				      switchdev_deferred_func_t *func)
+{
+	struct switchdev_deferred_item *dfitem;
+
+	dfitem = kmalloc_flex(*dfitem, data, data_len, GFP_ATOMIC);
+	if (!dfitem)
+		return -ENOMEM;
+	dfitem->dev = dev;
+	dfitem->func = func;
+	memcpy(dfitem->data, data, data_len);
+	netdev_hold(dev, &dfitem->dev_tracker, GFP_ATOMIC);
+	spin_lock_bh(&deferred_lock);
+	list_add_tail(&dfitem->list, &deferred);
+	spin_unlock_bh(&deferred_lock);
+	schedule_work(&deferred_process_work);
+	return 0;
+}
+
+static int switchdev_port_attr_notify(enum switchdev_notifier_type nt,
+				      struct net_device *dev,
+				      const struct switchdev_attr *attr,
+				      struct netlink_ext_ack *extack)
+{
+	int err;
+	int rc;
+
+	struct switchdev_notifier_port_attr_info attr_info = {
+		.attr = attr,
+		.handled = false,
+	};
+
+	rc = call_switchdev_blocking_notifiers(nt, dev,
+					       &attr_info.info, extack);
+	err = notifier_to_errno(rc);
+	if (err) {
+		WARN_ON(!attr_info.handled);
+		return err;
+	}
+
+	if (!attr_info.handled)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static int switchdev_port_attr_set_now(struct net_device *dev,
+				       const struct switchdev_attr *attr,
+				       struct netlink_ext_ack *extack)
+{
+	return switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
+					  extack);
+}
+
+static void switchdev_port_attr_set_deferred(struct net_device *dev,
+					     const void *data)
+{
+	const struct switchdev_attr *attr = data;
+	int err;
+
+	err = switchdev_port_attr_set_now(dev, attr, NULL);
+	if (err && err != -EOPNOTSUPP)
+		netdev_err(dev, "failed (err=%d) to set attribute (id=%d)\n",
+			   err, attr->id);
+	if (attr->complete)
+		attr->complete(dev, err, attr->complete_priv);
+}
+
+static int switchdev_port_attr_set_defer(struct net_device *dev,
+					 const struct switchdev_attr *attr)
+{
+	return switchdev_deferred_enqueue(dev, attr, sizeof(*attr),
+					  switchdev_port_attr_set_deferred);
+}
+
+/**
+ *	switchdev_port_attr_set - Set port attribute
+ *
+ *	@dev: port device
+ *	@attr: attribute to set
+ *	@extack: netlink extended ack, for error message propagation
+ *
+ *	rtnl_lock must be held and must not be in atomic section,
+ *	in case SWITCHDEV_F_DEFER flag is not set.
+ */
+int switchdev_port_attr_set(struct net_device *dev,
+			    const struct switchdev_attr *attr,
+			    struct netlink_ext_ack *extack)
+{
+	if (attr->flags & SWITCHDEV_F_DEFER)
+		return switchdev_port_attr_set_defer(dev, attr);
+	ASSERT_RTNL();
+	return switchdev_port_attr_set_now(dev, attr, extack);
+}
+EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
+
+static size_t switchdev_obj_size(const struct switchdev_obj *obj)
+{
+	switch (obj->id) {
+	case SWITCHDEV_OBJ_ID_PORT_VLAN:
+		return sizeof(struct switchdev_obj_port_vlan);
+	case SWITCHDEV_OBJ_ID_PORT_MDB:
+		return sizeof(struct switchdev_obj_port_mdb);
+	case SWITCHDEV_OBJ_ID_HOST_MDB:
+		return sizeof(struct switchdev_obj_port_mdb);
+	default:
+		BUG();
+	}
+	return 0;
+}
+
+static int switchdev_port_obj_notify(enum switchdev_notifier_type nt,
+				     struct net_device *dev,
+				     const struct switchdev_obj *obj,
+				     struct netlink_ext_ack *extack)
+{
+	int rc;
+	int err;
+
+	struct switchdev_notifier_port_obj_info obj_info = {
+		.obj = obj,
+		.handled = false,
+	};
+
+	rc = call_switchdev_blocking_notifiers(nt, dev, &obj_info.info, extack);
+	err = notifier_to_errno(rc);
+	if (err) {
+		WARN_ON(!obj_info.handled);
+		return err;
+	}
+	if (!obj_info.handled)
+		return -EOPNOTSUPP;
+	return 0;
+}
+
+static void switchdev_obj_id_to_helpful_msg(struct net_device *dev,
+					    enum switchdev_obj_id obj_id,
+					    int err, bool add)
+{
+	const char *action = add ? "add" : "del";
+	const char *reason = "";
+	const char *problem;
+	const char *obj_str;
+
+	switch (obj_id) {
+	case SWITCHDEV_OBJ_ID_UNDEFINED:
+		obj_str = "Undefined object";
+		problem = "Attempted operation is undefined, indicating a possible programming\n"
+			  "error.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_PORT_VLAN:
+		obj_str = "VLAN entry";
+		problem = "Failure in VLAN settings on this port might disrupt network\n"
+			  "segmentation or traffic isolation, affecting network partitioning.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_PORT_MDB:
+		obj_str = "Port Multicast Database entry";
+		problem = "Failure in updating the port's Multicast Database could lead to\n"
+			  "multicast forwarding issues.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_HOST_MDB:
+		obj_str = "Host Multicast Database entry";
+		problem = "Failure in updating the host's Multicast Database may impact multicast\n"
+			  "group memberships or traffic delivery, affecting multicast\n"
+			  "communication.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_MRP:
+		obj_str = "Media Redundancy Protocol configuration for port";
+		problem = "Failure to set MRP ring ID on this port prevents communication with\n"
+			  "the specified redundancy ring, resulting in an inability to engage\n"
+			  "in MRP-based network operations.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_RING_TEST_MRP:
+		obj_str = "MRP Test Frame Operations for port";
+		problem = "Failure to generate/monitor MRP test frames may lead to inability to\n"
+			  "assess the ring's operational integrity and fault response, hindering\n"
+			  "proactive network management.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_RING_ROLE_MRP:
+		obj_str = "MRP Ring Role Configuration";
+		problem = "Improper MRP ring role configuration may create conflicts in the ring,\n"
+			  "disrupting communication for all participants, or isolate the local\n"
+			  "system from the ring, hindering its ability to communicate with other\n"
+			  "participants.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_RING_STATE_MRP:
+		obj_str = "MRP Ring State Configuration";
+		problem = "Failure to correctly set the MRP ring state can result in network\n"
+			  "loops or leave segments without communication. In a Closed state,\n"
+			  "it maintains loop prevention by blocking one MRM port, while an Open\n"
+			  "state activates in response to failures, changing port states to\n"
+			  "preserve network connectivity.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_IN_TEST_MRP:
+		obj_str = "MRP_InTest Frame Generation Configuration";
+		problem = "Failure in managing MRP_InTest frame generation can misjudge the\n"
+			  "interconnection ring's state, leading to incorrect blocking or\n"
+			  "unblocking of the I/C port. This misconfiguration might result\n"
+			  "in unintended network loops or isolate critical network segments,\n"
+			  "compromising network integrity and reliability.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_IN_ROLE_MRP:
+		obj_str = "Interconnection Ring Role Configuration";
+		problem = "Failure in incorrect assignment of interconnection ring roles\n"
+			  "(MIM/MIC) can impair the formation of the interconnection rings.\n";
+		break;
+	case SWITCHDEV_OBJ_ID_IN_STATE_MRP:
+		obj_str = "Interconnection Ring State Configuration";
+		problem = "Failure in updating the interconnection ring state can lead in\n"
+			  "case of Open state to incorrect blocking or unblocking of the\n"
+			  "I/C port, resulting in unintended network loops or isolation\n"
+			  "of critical network\n";
+		break;
+	default:
+		obj_str = "Unknown object";
+		problem	= "Indicating a possible programming error.\n";
+	}
+
+	switch (err) {
+	case -ENOSPC:
+		reason = "Current HW/SW setup lacks sufficient resources.\n";
+		break;
+	}
+
+	netdev_err(dev, "Failed to %s %s (object id=%d) with error: %pe (%d).\n%s%s\n",
+		   action, obj_str, obj_id, ERR_PTR(err), err, problem, reason);
+}
+
+static void switchdev_port_obj_add_deferred(struct net_device *dev,
+					    const void *data)
+{
+	const struct switchdev_obj *obj = data;
+	int err;
+
+	ASSERT_RTNL();
+	err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
+					dev, obj, NULL);
+	if (err && err != -EOPNOTSUPP)
+		switchdev_obj_id_to_helpful_msg(dev, obj->id, err, true);
+	if (obj->complete)
+		obj->complete(dev, err, obj->complete_priv);
+}
+
+static int switchdev_port_obj_add_defer(struct net_device *dev,
+					const struct switchdev_obj *obj)
+{
+	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
+					  switchdev_port_obj_add_deferred);
+}
+
+/**
+ *	switchdev_port_obj_add - Add port object
+ *
+ *	@dev: port device
+ *	@obj: object to add
+ *	@extack: netlink extended ack
+ *
+ *	rtnl_lock must be held and must not be in atomic section,
+ *	in case SWITCHDEV_F_DEFER flag is not set.
+ */
+int switchdev_port_obj_add(struct net_device *dev,
+			   const struct switchdev_obj *obj,
+			   struct netlink_ext_ack *extack)
+{
+	if (obj->flags & SWITCHDEV_F_DEFER)
+		return switchdev_port_obj_add_defer(dev, obj);
+	ASSERT_RTNL();
+	return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
+					 dev, obj, extack);
+}
+EXPORT_SYMBOL_GPL(switchdev_port_obj_add);
+
+static int switchdev_port_obj_del_now(struct net_device *dev,
+				      const struct switchdev_obj *obj)
+{
+	return switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_DEL,
+					 dev, obj, NULL);
+}
+
+static void switchdev_port_obj_del_deferred(struct net_device *dev,
+					    const void *data)
+{
+	const struct switchdev_obj *obj = data;
+	int err;
+
+	err = switchdev_port_obj_del_now(dev, obj);
+	if (err && err != -EOPNOTSUPP)
+		switchdev_obj_id_to_helpful_msg(dev, obj->id, err, false);
+	if (obj->complete)
+		obj->complete(dev, err, obj->complete_priv);
+}
+
+static int switchdev_port_obj_del_defer(struct net_device *dev,
+					const struct switchdev_obj *obj)
+{
+	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
+					  switchdev_port_obj_del_deferred);
+}
+
+/**
+ *	switchdev_port_obj_del - Delete port object
+ *
+ *	@dev: port device
+ *	@obj: object to delete
+ *
+ *	rtnl_lock must be held and must not be in atomic section,
+ *	in case SWITCHDEV_F_DEFER flag is not set.
+ */
+int switchdev_port_obj_del(struct net_device *dev,
+			   const struct switchdev_obj *obj)
+{
+	if (obj->flags & SWITCHDEV_F_DEFER)
+		return switchdev_port_obj_del_defer(dev, obj);
+	ASSERT_RTNL();
+	return switchdev_port_obj_del_now(dev, obj);
+}
+EXPORT_SYMBOL_GPL(switchdev_port_obj_del);
+
+/**
+ *	switchdev_port_obj_act_is_deferred - Is object action pending?
+ *
+ *	@dev: port device
+ *	@nt: type of action; add or delete
+ *	@obj: object to test
+ *
+ *	Returns true if a deferred item is pending, which is
+ *	equivalent to the action @nt on an object @obj.
+ *
+ *	rtnl_lock must be held.
+ */
+bool switchdev_port_obj_act_is_deferred(struct net_device *dev,
+					enum switchdev_notifier_type nt,
+					const struct switchdev_obj *obj)
+{
+	struct switchdev_deferred_item *dfitem;
+	bool found = false;
+
+	ASSERT_RTNL();
+
+	spin_lock_bh(&deferred_lock);
+
+	list_for_each_entry(dfitem, &deferred, list) {
+		if (dfitem->dev != dev)
+			continue;
+
+		if ((dfitem->func == switchdev_port_obj_add_deferred &&
+		     nt == SWITCHDEV_PORT_OBJ_ADD) ||
+		    (dfitem->func == switchdev_port_obj_del_deferred &&
+		     nt == SWITCHDEV_PORT_OBJ_DEL)) {
+			if (switchdev_obj_eq((const void *)dfitem->data, obj)) {
+				found = true;
+				break;
+			}
+		}
+	}
+
+	spin_unlock_bh(&deferred_lock);
+
+	return found;
+}
+EXPORT_SYMBOL_GPL(switchdev_port_obj_act_is_deferred);
+
+static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
+static RAW_NOTIFIER_HEAD(switchdev_blocking_notif_chain);
+
+/**
+ *	register_switchdev_notifier - Register notifier
+ *	@nb: notifier_block
+ *
+ *	Register switch device notifier.
+ */
+int register_switchdev_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
+}
+EXPORT_SYMBOL_GPL(register_switchdev_notifier);
+
+/**
+ *	unregister_switchdev_notifier - Unregister notifier
+ *	@nb: notifier_block
+ *
+ *	Unregister switch device notifier.
+ */
+int unregister_switchdev_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
+
+/**
+ *	call_switchdev_notifiers - Call notifiers
+ *	@val: value passed unmodified to notifier function
+ *	@dev: port device
+ *	@info: notifier information data
+ *	@extack: netlink extended ack
+ *	Call all network notifier blocks.
+ */
+int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
+			     struct switchdev_notifier_info *info,
+			     struct netlink_ext_ack *extack)
+{
+	info->dev = dev;
+	info->extack = extack;
+	return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
+}
+EXPORT_SYMBOL_GPL(call_switchdev_notifiers);
+
+int register_switchdev_blocking_notifier(struct notifier_block *nb)
+{
+	struct raw_notifier_head *chain = &switchdev_blocking_notif_chain;
+	int err;
+
+	rtnl_lock();
+	err = raw_notifier_chain_register(chain, nb);
+	rtnl_unlock();
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(register_switchdev_blocking_notifier);
+
+int unregister_switchdev_blocking_notifier(struct notifier_block *nb)
+{
+	struct raw_notifier_head *chain = &switchdev_blocking_notif_chain;
+	int err;
+
+	rtnl_lock();
+	err = raw_notifier_chain_unregister(chain, nb);
+	rtnl_unlock();
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(unregister_switchdev_blocking_notifier);
+
+int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
+				      struct switchdev_notifier_info *info,
+				      struct netlink_ext_ack *extack)
+{
+	ASSERT_RTNL();
+	info->dev = dev;
+	info->extack = extack;
+	return raw_notifier_call_chain(&switchdev_blocking_notif_chain,
+				       val, info);
+}
+EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);
+
+struct switchdev_nested_priv {
+	bool (*check_cb)(const struct net_device *dev);
+	bool (*foreign_dev_check_cb)(const struct net_device *dev,
+				     const struct net_device *foreign_dev);
+	const struct net_device *dev;
+	struct net_device *lower_dev;
+};
+
+static int switchdev_lower_dev_walk(struct net_device *lower_dev,
+				    struct netdev_nested_priv *priv)
+{
+	struct switchdev_nested_priv *switchdev_priv = priv->data;
+	bool (*foreign_dev_check_cb)(const struct net_device *dev,
+				     const struct net_device *foreign_dev);
+	bool (*check_cb)(const struct net_device *dev);
+	const struct net_device *dev;
+
+	check_cb = switchdev_priv->check_cb;
+	foreign_dev_check_cb = switchdev_priv->foreign_dev_check_cb;
+	dev = switchdev_priv->dev;
+
+	if (check_cb(lower_dev) && !foreign_dev_check_cb(lower_dev, dev)) {
+		switchdev_priv->lower_dev = lower_dev;
+		return 1;
+	}
+
+	return 0;
+}
+
+static struct net_device *
+switchdev_lower_dev_find_rcu(struct net_device *dev,
+			     bool (*check_cb)(const struct net_device *dev),
+			     bool (*foreign_dev_check_cb)(const struct net_device *dev,
+							  const struct net_device *foreign_dev))
+{
+	struct switchdev_nested_priv switchdev_priv = {
+		.check_cb = check_cb,
+		.foreign_dev_check_cb = foreign_dev_check_cb,
+		.dev = dev,
+		.lower_dev = NULL,
+	};
+	struct netdev_nested_priv priv = {
+		.data = &switchdev_priv,
+	};
+
+	netdev_walk_all_lower_dev_rcu(dev, switchdev_lower_dev_walk, &priv);
+
+	return switchdev_priv.lower_dev;
+}
+
+static struct net_device *
+switchdev_lower_dev_find(struct net_device *dev,
+			 bool (*check_cb)(const struct net_device *dev),
+			 bool (*foreign_dev_check_cb)(const struct net_device *dev,
+						      const struct net_device *foreign_dev))
+{
+	struct switchdev_nested_priv switchdev_priv = {
+		.check_cb = check_cb,
+		.foreign_dev_check_cb = foreign_dev_check_cb,
+		.dev = dev,
+		.lower_dev = NULL,
+	};
+	struct netdev_nested_priv priv = {
+		.data = &switchdev_priv,
+	};
+
+	netdev_walk_all_lower_dev(dev, switchdev_lower_dev_walk, &priv);
+
+	return switchdev_priv.lower_dev;
+}
+
+static int __switchdev_handle_fdb_event_to_device(struct net_device *dev,
+		struct net_device *orig_dev, unsigned long event,
+		const struct switchdev_notifier_fdb_info *fdb_info,
+		bool (*check_cb)(const struct net_device *dev),
+		bool (*foreign_dev_check_cb)(const struct net_device *dev,
+					     const struct net_device *foreign_dev),
+		int (*mod_cb)(struct net_device *dev, struct net_device *orig_dev,
+			      unsigned long event, const void *ctx,
+			      const struct switchdev_notifier_fdb_info *fdb_info))
+{
+	const struct switchdev_notifier_info *info = &fdb_info->info;
+	struct net_device *br, *lower_dev, *switchdev;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	if (check_cb(dev))
+		return mod_cb(dev, orig_dev, event, info->ctx, fdb_info);
+
+	/* Recurse through lower interfaces in case the FDB entry is pointing
+	 * towards a bridge or a LAG device.
+	 */
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		/* Do not propagate FDB entries across bridges */
+		if (netif_is_bridge_master(lower_dev))
+			continue;
+
+		/* Bridge ports might be either us, or LAG interfaces
+		 * that we offload.
+		 */
+		if (!check_cb(lower_dev) &&
+		    !switchdev_lower_dev_find_rcu(lower_dev, check_cb,
+						  foreign_dev_check_cb))
+			continue;
+
+		err = __switchdev_handle_fdb_event_to_device(lower_dev, orig_dev,
+							     event, fdb_info, check_cb,
+							     foreign_dev_check_cb,
+							     mod_cb);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	/* Event is neither on a bridge nor a LAG. Check whether it is on an
+	 * interface that is in a bridge with us.
+	 */
+	br = netdev_master_upper_dev_get_rcu(dev);
+	if (!br || !netif_is_bridge_master(br))
+		return 0;
+
+	switchdev = switchdev_lower_dev_find_rcu(br, check_cb, foreign_dev_check_cb);
+	if (!switchdev)
+		return 0;
+
+	if (!foreign_dev_check_cb(switchdev, dev))
+		return err;
+
+	return __switchdev_handle_fdb_event_to_device(br, orig_dev, event, fdb_info,
+						      check_cb, foreign_dev_check_cb,
+						      mod_cb);
+}
+
+int switchdev_handle_fdb_event_to_device(struct net_device *dev, unsigned long event,
+		const struct switchdev_notifier_fdb_info *fdb_info,
+		bool (*check_cb)(const struct net_device *dev),
+		bool (*foreign_dev_check_cb)(const struct net_device *dev,
+					     const struct net_device *foreign_dev),
+		int (*mod_cb)(struct net_device *dev, struct net_device *orig_dev,
+			      unsigned long event, const void *ctx,
+			      const struct switchdev_notifier_fdb_info *fdb_info))
+{
+	int err;
+
+	err = __switchdev_handle_fdb_event_to_device(dev, dev, event, fdb_info,
+						     check_cb, foreign_dev_check_cb,
+						     mod_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_fdb_event_to_device);
+
+static int __switchdev_handle_port_obj_add(struct net_device *dev,
+			struct switchdev_notifier_port_obj_info *port_obj_info,
+			bool (*check_cb)(const struct net_device *dev),
+			bool (*foreign_dev_check_cb)(const struct net_device *dev,
+						     const struct net_device *foreign_dev),
+			int (*add_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_obj *obj,
+				      struct netlink_ext_ack *extack))
+{
+	struct switchdev_notifier_info *info = &port_obj_info->info;
+	struct net_device *br, *lower_dev, *switchdev;
+	struct netlink_ext_ack *extack;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	extack = switchdev_notifier_info_to_extack(info);
+
+	if (check_cb(dev)) {
+		err = add_cb(dev, info->ctx, port_obj_info->obj, extack);
+		if (err != -EOPNOTSUPP)
+			port_obj_info->handled = true;
+		return err;
+	}
+
+	/* Switch ports might be stacked under e.g. a LAG. Ignore the
+	 * unsupported devices, another driver might be able to handle them. But
+	 * propagate to the callers any hard errors.
+	 *
+	 * If the driver does its own bookkeeping of stacked ports, it's not
+	 * necessary to go through this helper.
+	 */
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		if (netif_is_bridge_master(lower_dev))
+			continue;
+
+		/* When searching for switchdev interfaces that are neighbors
+		 * of foreign ones, and @dev is a bridge, do not recurse on the
+		 * foreign interface again, it was already visited.
+		 */
+		if (foreign_dev_check_cb && !check_cb(lower_dev) &&
+		    !switchdev_lower_dev_find(lower_dev, check_cb, foreign_dev_check_cb))
+			continue;
+
+		err = __switchdev_handle_port_obj_add(lower_dev, port_obj_info,
+						      check_cb, foreign_dev_check_cb,
+						      add_cb);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	/* Event is neither on a bridge nor a LAG. Check whether it is on an
+	 * interface that is in a bridge with us.
+	 */
+	if (!foreign_dev_check_cb || port_obj_info->obj->flags & SWITCHDEV_F_NO_FOREIGN)
+		return err;
+
+	br = netdev_master_upper_dev_get(dev);
+	if (!br || !netif_is_bridge_master(br))
+		return err;
+
+	switchdev = switchdev_lower_dev_find(br, check_cb, foreign_dev_check_cb);
+	if (!switchdev)
+		return err;
+
+	if (!foreign_dev_check_cb(switchdev, dev))
+		return err;
+
+	return __switchdev_handle_port_obj_add(br, port_obj_info, check_cb,
+					       foreign_dev_check_cb, add_cb);
+}
+
+/* Pass through a port object addition, if @dev passes @check_cb, or replicate
+ * it towards all lower interfaces of @dev that pass @check_cb, if @dev is a
+ * bridge or a LAG.
+ */
+int switchdev_handle_port_obj_add(struct net_device *dev,
+			struct switchdev_notifier_port_obj_info *port_obj_info,
+			bool (*check_cb)(const struct net_device *dev),
+			int (*add_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_obj *obj,
+				      struct netlink_ext_ack *extack))
+{
+	int err;
+
+	err = __switchdev_handle_port_obj_add(dev, port_obj_info, check_cb,
+					      NULL, add_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add);
+
+/* Same as switchdev_handle_port_obj_add(), except if object is notified on a
+ * @dev that passes @foreign_dev_check_cb, it is replicated towards all devices
+ * that pass @check_cb and are in the same bridge as @dev.
+ */
+int switchdev_handle_port_obj_add_foreign(struct net_device *dev,
+			struct switchdev_notifier_port_obj_info *port_obj_info,
+			bool (*check_cb)(const struct net_device *dev),
+			bool (*foreign_dev_check_cb)(const struct net_device *dev,
+						     const struct net_device *foreign_dev),
+			int (*add_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_obj *obj,
+				      struct netlink_ext_ack *extack))
+{
+	int err;
+
+	err = __switchdev_handle_port_obj_add(dev, port_obj_info, check_cb,
+					      foreign_dev_check_cb, add_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_add_foreign);
+
+static int __switchdev_handle_port_obj_del(struct net_device *dev,
+			struct switchdev_notifier_port_obj_info *port_obj_info,
+			bool (*check_cb)(const struct net_device *dev),
+			bool (*foreign_dev_check_cb)(const struct net_device *dev,
+						     const struct net_device *foreign_dev),
+			int (*del_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_obj *obj))
+{
+	struct switchdev_notifier_info *info = &port_obj_info->info;
+	struct net_device *br, *lower_dev, *switchdev;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	if (check_cb(dev)) {
+		err = del_cb(dev, info->ctx, port_obj_info->obj);
+		if (err != -EOPNOTSUPP)
+			port_obj_info->handled = true;
+		return err;
+	}
+
+	/* Switch ports might be stacked under e.g. a LAG. Ignore the
+	 * unsupported devices, another driver might be able to handle them. But
+	 * propagate to the callers any hard errors.
+	 *
+	 * If the driver does its own bookkeeping of stacked ports, it's not
+	 * necessary to go through this helper.
+	 */
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		if (netif_is_bridge_master(lower_dev))
+			continue;
+
+		/* When searching for switchdev interfaces that are neighbors
+		 * of foreign ones, and @dev is a bridge, do not recurse on the
+		 * foreign interface again, it was already visited.
+		 */
+		if (foreign_dev_check_cb && !check_cb(lower_dev) &&
+		    !switchdev_lower_dev_find(lower_dev, check_cb, foreign_dev_check_cb))
+			continue;
+
+		err = __switchdev_handle_port_obj_del(lower_dev, port_obj_info,
+						      check_cb, foreign_dev_check_cb,
+						      del_cb);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	/* Event is neither on a bridge nor a LAG. Check whether it is on an
+	 * interface that is in a bridge with us.
+	 */
+	if (!foreign_dev_check_cb)
+		return err;
+
+	br = netdev_master_upper_dev_get(dev);
+	if (!br || !netif_is_bridge_master(br))
+		return err;
+
+	switchdev = switchdev_lower_dev_find(br, check_cb, foreign_dev_check_cb);
+	if (!switchdev)
+		return err;
+
+	if (!foreign_dev_check_cb(switchdev, dev))
+		return err;
+
+	return __switchdev_handle_port_obj_del(br, port_obj_info, check_cb,
+					       foreign_dev_check_cb, del_cb);
+}
+
+/* Pass through a port object deletion, if @dev passes @check_cb, or replicate
+ * it towards all lower interfaces of @dev that pass @check_cb, if @dev is a
+ * bridge or a LAG.
+ */
+int switchdev_handle_port_obj_del(struct net_device *dev,
+			struct switchdev_notifier_port_obj_info *port_obj_info,
+			bool (*check_cb)(const struct net_device *dev),
+			int (*del_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_obj *obj))
+{
+	int err;
+
+	err = __switchdev_handle_port_obj_del(dev, port_obj_info, check_cb,
+					      NULL, del_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del);
+
+/* Same as switchdev_handle_port_obj_del(), except if object is notified on a
+ * @dev that passes @foreign_dev_check_cb, it is replicated towards all devices
+ * that pass @check_cb and are in the same bridge as @dev.
+ */
+int switchdev_handle_port_obj_del_foreign(struct net_device *dev,
+			struct switchdev_notifier_port_obj_info *port_obj_info,
+			bool (*check_cb)(const struct net_device *dev),
+			bool (*foreign_dev_check_cb)(const struct net_device *dev,
+						     const struct net_device *foreign_dev),
+			int (*del_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_obj *obj))
+{
+	int err;
+
+	err = __switchdev_handle_port_obj_del(dev, port_obj_info, check_cb,
+					      foreign_dev_check_cb, del_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_port_obj_del_foreign);
+
+static int __switchdev_handle_port_attr_set(struct net_device *dev,
+			struct switchdev_notifier_port_attr_info *port_attr_info,
+			bool (*check_cb)(const struct net_device *dev),
+			int (*set_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_attr *attr,
+				      struct netlink_ext_ack *extack))
+{
+	struct switchdev_notifier_info *info = &port_attr_info->info;
+	struct netlink_ext_ack *extack;
+	struct net_device *lower_dev;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	extack = switchdev_notifier_info_to_extack(info);
+
+	if (check_cb(dev)) {
+		err = set_cb(dev, info->ctx, port_attr_info->attr, extack);
+		if (err != -EOPNOTSUPP)
+			port_attr_info->handled = true;
+		return err;
+	}
+
+	/* Switch ports might be stacked under e.g. a LAG. Ignore the
+	 * unsupported devices, another driver might be able to handle them. But
+	 * propagate to the callers any hard errors.
+	 *
+	 * If the driver does its own bookkeeping of stacked ports, it's not
+	 * necessary to go through this helper.
+	 */
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		if (netif_is_bridge_master(lower_dev))
+			continue;
+
+		err = __switchdev_handle_port_attr_set(lower_dev, port_attr_info,
+						       check_cb, set_cb);
+		if (err && err != -EOPNOTSUPP)
+			return err;
+	}
+
+	return err;
+}
+
+int switchdev_handle_port_attr_set(struct net_device *dev,
+			struct switchdev_notifier_port_attr_info *port_attr_info,
+			bool (*check_cb)(const struct net_device *dev),
+			int (*set_cb)(struct net_device *dev, const void *ctx,
+				      const struct switchdev_attr *attr,
+				      struct netlink_ext_ack *extack))
+{
+	int err;
+
+	err = __switchdev_handle_port_attr_set(dev, port_attr_info, check_cb,
+					       set_cb);
+	if (err == -EOPNOTSUPP)
+		err = 0;
+	return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_handle_port_attr_set);
+
+int switchdev_bridge_port_offload(struct net_device *brport_dev,
+				  struct net_device *dev, const void *ctx,
+				  struct notifier_block *atomic_nb,
+				  struct notifier_block *blocking_nb,
+				  bool tx_fwd_offload,
+				  struct netlink_ext_ack *extack)
+{
+	struct switchdev_notifier_brport_info brport_info = {
+		.brport = {
+			.dev = dev,
+			.ctx = ctx,
+			.atomic_nb = atomic_nb,
+			.blocking_nb = blocking_nb,
+			.tx_fwd_offload = tx_fwd_offload,
+		},
+	};
+	int err;
+
+	ASSERT_RTNL();
+
+	err = call_switchdev_blocking_notifiers(SWITCHDEV_BRPORT_OFFLOADED,
+						brport_dev, &brport_info.info,
+						extack);
+	return notifier_to_errno(err);
+}
+EXPORT_SYMBOL_GPL(switchdev_bridge_port_offload);
+
+void switchdev_bridge_port_unoffload(struct net_device *brport_dev,
+				     const void *ctx,
+				     struct notifier_block *atomic_nb,
+				     struct notifier_block *blocking_nb)
+{
+	struct switchdev_notifier_brport_info brport_info = {
+		.brport = {
+			.ctx = ctx,
+			.atomic_nb = atomic_nb,
+			.blocking_nb = blocking_nb,
+		},
+	};
+
+	ASSERT_RTNL();
+
+	call_switchdev_blocking_notifiers(SWITCHDEV_BRPORT_UNOFFLOADED,
+					  brport_dev, &brport_info.info,
+					  NULL);
+}
+EXPORT_SYMBOL_GPL(switchdev_bridge_port_unoffload);
+
+int switchdev_bridge_port_replay(struct net_device *brport_dev,
+				 struct net_device *dev, const void *ctx,
+				 struct notifier_block *atomic_nb,
+				 struct notifier_block *blocking_nb,
+				 struct netlink_ext_ack *extack)
+{
+	struct switchdev_notifier_brport_info brport_info = {
+		.brport = {
+			.dev = dev,
+			.ctx = ctx,
+			.atomic_nb = atomic_nb,
+			.blocking_nb = blocking_nb,
+		},
+	};
+	int err;
+
+	ASSERT_RTNL();
+
+	err = call_switchdev_blocking_notifiers(SWITCHDEV_BRPORT_REPLAY,
+						brport_dev, &brport_info.info,
+						extack);
+	return notifier_to_errno(err);
+}
+EXPORT_SYMBOL_GPL(switchdev_bridge_port_replay);