Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 480 insertions, 0 deletions

diff --git a/drivers/net/netdevsim/hwstats.c b/drivers/net/netdevsim/hwstats.c
new file mode 100644
index 000000000..14234a4cc
--- /dev/null
+++ b/drivers/net/netdevsim/hwstats.c
@@ -0,0 +1,480 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/debugfs.h>
+
+#include "netdevsim.h"
+
+#define NSIM_DEV_HWSTATS_TRAFFIC_MS	100
+
+static struct list_head *
+nsim_dev_hwstats_get_list_head(struct nsim_dev_hwstats *hwstats,
+			       enum netdev_offload_xstats_type type)
+{
+	switch (type) {
+	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
+		return &hwstats->l3_list;
+	}
+
+	WARN_ON_ONCE(1);
+	return NULL;
+}
+
+static void nsim_dev_hwstats_traffic_bump(struct nsim_dev_hwstats *hwstats,
+					  enum netdev_offload_xstats_type type)
+{
+	struct nsim_dev_hwstats_netdev *hwsdev;
+	struct list_head *hwsdev_list;
+
+	hwsdev_list = nsim_dev_hwstats_get_list_head(hwstats, type);
+	if (WARN_ON(!hwsdev_list))
+		return;
+
+	list_for_each_entry(hwsdev, hwsdev_list, list) {
+		if (hwsdev->enabled) {
+			hwsdev->stats.rx_packets += 1;
+			hwsdev->stats.tx_packets += 2;
+			hwsdev->stats.rx_bytes += 100;
+			hwsdev->stats.tx_bytes += 300;
+		}
+	}
+}
+
+static void nsim_dev_hwstats_traffic_work(struct work_struct *work)
+{
+	struct nsim_dev_hwstats *hwstats;
+
+	hwstats = container_of(work, struct nsim_dev_hwstats, traffic_dw.work);
+	mutex_lock(&hwstats->hwsdev_list_lock);
+	nsim_dev_hwstats_traffic_bump(hwstats, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+
+	schedule_delayed_work(&hwstats->traffic_dw,
+			      msecs_to_jiffies(NSIM_DEV_HWSTATS_TRAFFIC_MS));
+}
+
+static struct nsim_dev_hwstats_netdev *
+nsim_dev_hwslist_find_hwsdev(struct list_head *hwsdev_list,
+			     int ifindex)
+{
+	struct nsim_dev_hwstats_netdev *hwsdev;
+
+	list_for_each_entry(hwsdev, hwsdev_list, list) {
+		if (hwsdev->netdev->ifindex == ifindex)
+			return hwsdev;
+	}
+
+	return NULL;
+}
+
+static int nsim_dev_hwsdev_enable(struct nsim_dev_hwstats_netdev *hwsdev,
+				  struct netlink_ext_ack *extack)
+{
+	if (hwsdev->fail_enable) {
+		hwsdev->fail_enable = false;
+		NL_SET_ERR_MSG_MOD(extack, "Stats enablement set to fail");
+		return -ECANCELED;
+	}
+
+	hwsdev->enabled = true;
+	return 0;
+}
+
+static void nsim_dev_hwsdev_disable(struct nsim_dev_hwstats_netdev *hwsdev)
+{
+	hwsdev->enabled = false;
+	memset(&hwsdev->stats, 0, sizeof(hwsdev->stats));
+}
+
+static int
+nsim_dev_hwsdev_report_delta(struct nsim_dev_hwstats_netdev *hwsdev,
+			     struct netdev_notifier_offload_xstats_info *info)
+{
+	netdev_offload_xstats_report_delta(info->report_delta, &hwsdev->stats);
+	memset(&hwsdev->stats, 0, sizeof(hwsdev->stats));
+	return 0;
+}
+
+static void
+nsim_dev_hwsdev_report_used(struct nsim_dev_hwstats_netdev *hwsdev,
+			    struct netdev_notifier_offload_xstats_info *info)
+{
+	if (hwsdev->enabled)
+		netdev_offload_xstats_report_used(info->report_used);
+}
+
+static int nsim_dev_hwstats_event_off_xstats(struct nsim_dev_hwstats *hwstats,
+					     struct net_device *dev,
+					     unsigned long event, void *ptr)
+{
+	struct netdev_notifier_offload_xstats_info *info;
+	struct nsim_dev_hwstats_netdev *hwsdev;
+	struct list_head *hwsdev_list;
+	int err = 0;
+
+	info = ptr;
+	hwsdev_list = nsim_dev_hwstats_get_list_head(hwstats, info->type);
+	if (!hwsdev_list)
+		return 0;
+
+	mutex_lock(&hwstats->hwsdev_list_lock);
+
+	hwsdev = nsim_dev_hwslist_find_hwsdev(hwsdev_list, dev->ifindex);
+	if (!hwsdev)
+		goto out;
+
+	switch (event) {
+	case NETDEV_OFFLOAD_XSTATS_ENABLE:
+		err = nsim_dev_hwsdev_enable(hwsdev, info->info.extack);
+		break;
+	case NETDEV_OFFLOAD_XSTATS_DISABLE:
+		nsim_dev_hwsdev_disable(hwsdev);
+		break;
+	case NETDEV_OFFLOAD_XSTATS_REPORT_USED:
+		nsim_dev_hwsdev_report_used(hwsdev, info);
+		break;
+	case NETDEV_OFFLOAD_XSTATS_REPORT_DELTA:
+		err = nsim_dev_hwsdev_report_delta(hwsdev, info);
+		break;
+	}
+
+out:
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+	return err;
+}
+
+static void nsim_dev_hwsdev_fini(struct nsim_dev_hwstats_netdev *hwsdev)
+{
+	dev_put(hwsdev->netdev);
+	kfree(hwsdev);
+}
+
+static void
+__nsim_dev_hwstats_event_unregister(struct nsim_dev_hwstats *hwstats,
+				    struct net_device *dev,
+				    enum netdev_offload_xstats_type type)
+{
+	struct nsim_dev_hwstats_netdev *hwsdev;
+	struct list_head *hwsdev_list;
+
+	hwsdev_list = nsim_dev_hwstats_get_list_head(hwstats, type);
+	if (WARN_ON(!hwsdev_list))
+		return;
+
+	hwsdev = nsim_dev_hwslist_find_hwsdev(hwsdev_list, dev->ifindex);
+	if (!hwsdev)
+		return;
+
+	list_del(&hwsdev->list);
+	nsim_dev_hwsdev_fini(hwsdev);
+}
+
+static void nsim_dev_hwstats_event_unregister(struct nsim_dev_hwstats *hwstats,
+					      struct net_device *dev)
+{
+	mutex_lock(&hwstats->hwsdev_list_lock);
+	__nsim_dev_hwstats_event_unregister(hwstats, dev,
+					    NETDEV_OFFLOAD_XSTATS_TYPE_L3);
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+}
+
+static int nsim_dev_hwstats_event(struct nsim_dev_hwstats *hwstats,
+				  struct net_device *dev,
+				  unsigned long event, void *ptr)
+{
+	switch (event) {
+	case NETDEV_OFFLOAD_XSTATS_ENABLE:
+	case NETDEV_OFFLOAD_XSTATS_DISABLE:
+	case NETDEV_OFFLOAD_XSTATS_REPORT_USED:
+	case NETDEV_OFFLOAD_XSTATS_REPORT_DELTA:
+		return nsim_dev_hwstats_event_off_xstats(hwstats, dev,
+							 event, ptr);
+	case NETDEV_UNREGISTER:
+		nsim_dev_hwstats_event_unregister(hwstats, dev);
+		break;
+	}
+
+	return 0;
+}
+
+static int nsim_dev_netdevice_event(struct notifier_block *nb,
+				    unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct nsim_dev_hwstats *hwstats;
+	int err = 0;
+
+	hwstats = container_of(nb, struct nsim_dev_hwstats, netdevice_nb);
+	err = nsim_dev_hwstats_event(hwstats, dev, event, ptr);
+	if (err)
+		return notifier_from_errno(err);
+
+	return NOTIFY_OK;
+}
+
+static int
+nsim_dev_hwstats_enable_ifindex(struct nsim_dev_hwstats *hwstats,
+				int ifindex,
+				enum netdev_offload_xstats_type type,
+				struct list_head *hwsdev_list)
+{
+	struct nsim_dev_hwstats_netdev *hwsdev;
+	struct nsim_dev *nsim_dev;
+	struct net_device *netdev;
+	struct net *net;
+	int err = 0;
+
+	nsim_dev = container_of(hwstats, struct nsim_dev, hwstats);
+	net = nsim_dev_net(nsim_dev);
+
+	rtnl_lock();
+	mutex_lock(&hwstats->hwsdev_list_lock);
+	hwsdev = nsim_dev_hwslist_find_hwsdev(hwsdev_list, ifindex);
+	if (hwsdev)
+		goto out_unlock_list;
+
+	netdev = dev_get_by_index(net, ifindex);
+	if (!netdev) {
+		err = -ENODEV;
+		goto out_unlock_list;
+	}
+
+	hwsdev = kzalloc_obj(*hwsdev);
+	if (!hwsdev) {
+		err = -ENOMEM;
+		goto out_put_netdev;
+	}
+
+	hwsdev->netdev = netdev;
+	list_add_tail(&hwsdev->list, hwsdev_list);
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+
+	if (netdev_offload_xstats_enabled(netdev, type)) {
+		nsim_dev_hwsdev_enable(hwsdev, NULL);
+		rtnl_offload_xstats_notify(netdev);
+	}
+
+	rtnl_unlock();
+	return err;
+
+out_put_netdev:
+	dev_put(netdev);
+out_unlock_list:
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+	rtnl_unlock();
+	return err;
+}
+
+static int
+nsim_dev_hwstats_disable_ifindex(struct nsim_dev_hwstats *hwstats,
+				 int ifindex,
+				 enum netdev_offload_xstats_type type,
+				 struct list_head *hwsdev_list)
+{
+	struct nsim_dev_hwstats_netdev *hwsdev;
+	int err = 0;
+
+	rtnl_lock();
+	mutex_lock(&hwstats->hwsdev_list_lock);
+	hwsdev = nsim_dev_hwslist_find_hwsdev(hwsdev_list, ifindex);
+	if (hwsdev)
+		list_del(&hwsdev->list);
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+
+	if (!hwsdev) {
+		err = -ENOENT;
+		goto unlock_out;
+	}
+
+	if (netdev_offload_xstats_enabled(hwsdev->netdev, type)) {
+		netdev_offload_xstats_push_delta(hwsdev->netdev, type,
+						 &hwsdev->stats);
+		rtnl_offload_xstats_notify(hwsdev->netdev);
+	}
+	nsim_dev_hwsdev_fini(hwsdev);
+
+unlock_out:
+	rtnl_unlock();
+	return err;
+}
+
+static int
+nsim_dev_hwstats_fail_ifindex(struct nsim_dev_hwstats *hwstats,
+			      int ifindex,
+			      enum netdev_offload_xstats_type type,
+			      struct list_head *hwsdev_list)
+{
+	struct nsim_dev_hwstats_netdev *hwsdev;
+	int err = 0;
+
+	mutex_lock(&hwstats->hwsdev_list_lock);
+
+	hwsdev = nsim_dev_hwslist_find_hwsdev(hwsdev_list, ifindex);
+	if (!hwsdev) {
+		err = -ENOENT;
+		goto err_hwsdev_list_unlock;
+	}
+
+	hwsdev->fail_enable = true;
+
+err_hwsdev_list_unlock:
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+	return err;
+}
+
+enum nsim_dev_hwstats_do {
+	NSIM_DEV_HWSTATS_DO_DISABLE,
+	NSIM_DEV_HWSTATS_DO_ENABLE,
+	NSIM_DEV_HWSTATS_DO_FAIL,
+};
+
+struct nsim_dev_hwstats_fops {
+	enum nsim_dev_hwstats_do action;
+	enum netdev_offload_xstats_type type;
+};
+
+static ssize_t
+nsim_dev_hwstats_do_write(struct file *file,
+			  const char __user *data,
+			  size_t count, loff_t *ppos)
+{
+	struct nsim_dev_hwstats *hwstats = file->private_data;
+	const struct nsim_dev_hwstats_fops *hwsfops;
+	struct list_head *hwsdev_list;
+	int ifindex;
+	int err;
+
+	hwsfops = debugfs_get_aux(file);
+
+	err = kstrtoint_from_user(data, count, 0, &ifindex);
+	if (err)
+		return err;
+
+	hwsdev_list = nsim_dev_hwstats_get_list_head(hwstats, hwsfops->type);
+	if (WARN_ON(!hwsdev_list))
+		return -EINVAL;
+
+	switch (hwsfops->action) {
+	case NSIM_DEV_HWSTATS_DO_DISABLE:
+		err = nsim_dev_hwstats_disable_ifindex(hwstats, ifindex,
+						       hwsfops->type,
+						       hwsdev_list);
+		break;
+	case NSIM_DEV_HWSTATS_DO_ENABLE:
+		err = nsim_dev_hwstats_enable_ifindex(hwstats, ifindex,
+						      hwsfops->type,
+						      hwsdev_list);
+		break;
+	case NSIM_DEV_HWSTATS_DO_FAIL:
+		err = nsim_dev_hwstats_fail_ifindex(hwstats, ifindex,
+						    hwsfops->type,
+						    hwsdev_list);
+		break;
+	}
+	if (err)
+		return err;
+
+	return count;
+}
+
+static struct debugfs_short_fops debugfs_ops = {
+	.write = nsim_dev_hwstats_do_write,
+	.llseek = generic_file_llseek,
+};
+
+#define NSIM_DEV_HWSTATS_FOPS(ACTION, TYPE)			\
+	{							\
+		.action = ACTION,				\
+		.type = TYPE,					\
+	}
+
+static const struct nsim_dev_hwstats_fops nsim_dev_hwstats_l3_disable_fops =
+	NSIM_DEV_HWSTATS_FOPS(NSIM_DEV_HWSTATS_DO_DISABLE,
+			      NETDEV_OFFLOAD_XSTATS_TYPE_L3);
+
+static const struct nsim_dev_hwstats_fops nsim_dev_hwstats_l3_enable_fops =
+	NSIM_DEV_HWSTATS_FOPS(NSIM_DEV_HWSTATS_DO_ENABLE,
+			      NETDEV_OFFLOAD_XSTATS_TYPE_L3);
+
+static const struct nsim_dev_hwstats_fops nsim_dev_hwstats_l3_fail_fops =
+	NSIM_DEV_HWSTATS_FOPS(NSIM_DEV_HWSTATS_DO_FAIL,
+			      NETDEV_OFFLOAD_XSTATS_TYPE_L3);
+
+#undef NSIM_DEV_HWSTATS_FOPS
+
+int nsim_dev_hwstats_init(struct nsim_dev *nsim_dev)
+{
+	struct nsim_dev_hwstats *hwstats = &nsim_dev->hwstats;
+	struct net *net = nsim_dev_net(nsim_dev);
+	int err;
+
+	mutex_init(&hwstats->hwsdev_list_lock);
+	INIT_LIST_HEAD(&hwstats->l3_list);
+
+	hwstats->netdevice_nb.notifier_call = nsim_dev_netdevice_event;
+	err = register_netdevice_notifier_net(net, &hwstats->netdevice_nb);
+	if (err)
+		goto err_mutex_destroy;
+
+	hwstats->ddir = debugfs_create_dir("hwstats", nsim_dev->ddir);
+	if (IS_ERR(hwstats->ddir)) {
+		err = PTR_ERR(hwstats->ddir);
+		goto err_unregister_notifier;
+	}
+
+	hwstats->l3_ddir = debugfs_create_dir("l3", hwstats->ddir);
+	if (IS_ERR(hwstats->l3_ddir)) {
+		err = PTR_ERR(hwstats->l3_ddir);
+		goto err_remove_hwstats_recursive;
+	}
+
+	debugfs_create_file_aux("enable_ifindex", 0200, hwstats->l3_ddir, hwstats,
+			    &nsim_dev_hwstats_l3_enable_fops, &debugfs_ops);
+	debugfs_create_file_aux("disable_ifindex", 0200, hwstats->l3_ddir, hwstats,
+			    &nsim_dev_hwstats_l3_disable_fops, &debugfs_ops);
+	debugfs_create_file_aux("fail_next_enable", 0200, hwstats->l3_ddir, hwstats,
+			    &nsim_dev_hwstats_l3_fail_fops, &debugfs_ops);
+
+	INIT_DELAYED_WORK(&hwstats->traffic_dw,
+			  &nsim_dev_hwstats_traffic_work);
+	schedule_delayed_work(&hwstats->traffic_dw,
+			      msecs_to_jiffies(NSIM_DEV_HWSTATS_TRAFFIC_MS));
+	return 0;
+
+err_remove_hwstats_recursive:
+	debugfs_remove_recursive(hwstats->ddir);
+err_unregister_notifier:
+	unregister_netdevice_notifier_net(net, &hwstats->netdevice_nb);
+err_mutex_destroy:
+	mutex_destroy(&hwstats->hwsdev_list_lock);
+	return err;
+}
+
+static void nsim_dev_hwsdev_list_wipe(struct nsim_dev_hwstats *hwstats,
+				      enum netdev_offload_xstats_type type)
+{
+	struct nsim_dev_hwstats_netdev *hwsdev, *tmp;
+	struct list_head *hwsdev_list;
+
+	hwsdev_list = nsim_dev_hwstats_get_list_head(hwstats, type);
+	if (WARN_ON(!hwsdev_list))
+		return;
+
+	mutex_lock(&hwstats->hwsdev_list_lock);
+	list_for_each_entry_safe(hwsdev, tmp, hwsdev_list, list) {
+		list_del(&hwsdev->list);
+		nsim_dev_hwsdev_fini(hwsdev);
+	}
+	mutex_unlock(&hwstats->hwsdev_list_lock);
+}
+
+void nsim_dev_hwstats_exit(struct nsim_dev *nsim_dev)
+{
+	struct nsim_dev_hwstats *hwstats = &nsim_dev->hwstats;
+	struct net *net = nsim_dev_net(nsim_dev);
+
+	cancel_delayed_work_sync(&hwstats->traffic_dw);
+	debugfs_remove_recursive(hwstats->ddir);
+	unregister_netdevice_notifier_net(net, &hwstats->netdevice_nb);
+	nsim_dev_hwsdev_list_wipe(hwstats, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
+	mutex_destroy(&hwstats->hwsdev_list_lock);
+}