diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst
index 15f78e7..759907c 100644
--- a/Documentation/trace/events.rst
+++ b/Documentation/trace/events.rst
@@ -219,6 +219,20 @@ the function "security_prepare_creds" and less than the end of that function.
 The ".function" postfix can only be attached to values of size long, and can only
 be compared with "==" or "!=".
 
+Cpumask fields or scalar fields that encode a CPU number can be filtered using
+a user-provided cpumask in cpulist format. The format is as follows::
+
+  CPUS{$cpulist}
+
+Operators available to cpumask filtering are:
+
+& (intersection), ==, !=
+
+For example, this will filter events that have their .target_cpu field present
+in the given cpumask::
+
+  target_cpu & CPUS{17-42}
+
 5.2 Setting filters
 -------------------
 
diff --git a/fs/tracefs/Makefile b/fs/tracefs/Makefile
index 7c35a28..73c56da 100644
--- a/fs/tracefs/Makefile
+++ b/fs/tracefs/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 tracefs-objs	:= inode.o
+tracefs-objs	+= event_inode.o
 
 obj-$(CONFIG_TRACING)	+= tracefs.o
 
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
new file mode 100644
index 0000000..237c6f3
--- /dev/null
+++ b/fs/tracefs/event_inode.c
@@ -0,0 +1,807 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  event_inode.c - part of tracefs, a pseudo file system for activating tracing
+ *
+ *  Copyright (C) 2020-23 VMware Inc, author: Steven Rostedt (VMware) <rostedt@goodmis.org>
+ *  Copyright (C) 2020-23 VMware Inc, author: Ajay Kaher <akaher@vmware.com>
+ *
+ *  eventfs is used to dynamically create inodes and dentries based on the
+ *  meta data provided by the tracing system.
+ *
+ *  eventfs stores the meta-data of files/dirs and holds off on creating
+ *  inodes/dentries of the files. When accessed, the eventfs will create the
+ *  inodes/dentries in a just-in-time (JIT) manner. The eventfs will clean up
+ *  and delete the inodes/dentries when they are no longer referenced.
+ */
+#include <linux/fsnotify.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/workqueue.h>
+#include <linux/security.h>
+#include <linux/tracefs.h>
+#include <linux/kref.h>
+#include <linux/delay.h>
+#include "internal.h"
+
+struct eventfs_inode {
+	struct list_head	e_top_files;
+};
+
+/*
+ * struct eventfs_file - hold the properties of the eventfs files and
+ *                       directories.
+ * @name:	the name of the file or directory to create
+ * @d_parent:   holds parent's dentry
+ * @dentry:     once accessed holds dentry
+ * @list:	file or directory to be added to parent directory
+ * @ei:		list of files and directories within directory
+ * @fop:	file_operations for file or directory
+ * @iop:	inode_operations for file or directory
+ * @data:	something that the caller will want to get to later on
+ * @mode:	the permission that the file or directory should have
+ */
+struct eventfs_file {
+	const char			*name;
+	struct dentry			*d_parent;
+	struct dentry			*dentry;
+	struct list_head		list;
+	struct eventfs_inode		*ei;
+	const struct file_operations	*fop;
+	const struct inode_operations	*iop;
+	/*
+	 * Union - used for deletion
+	 * @del_list:	list of eventfs_file to delete
+	 * @rcu:	eventfs_file to delete in RCU
+	 * @is_freed:	node is freed if one of the above is set
+	 */
+	union {
+		struct list_head	del_list;
+		struct rcu_head		rcu;
+		unsigned long		is_freed;
+	};
+	void				*data;
+	umode_t				mode;
+};
+
+static DEFINE_MUTEX(eventfs_mutex);
+DEFINE_STATIC_SRCU(eventfs_srcu);
+
+static struct dentry *eventfs_root_lookup(struct inode *dir,
+					  struct dentry *dentry,
+					  unsigned int flags);
+static int dcache_dir_open_wrapper(struct inode *inode, struct file *file);
+static int eventfs_release(struct inode *inode, struct file *file);
+
+static const struct inode_operations eventfs_root_dir_inode_operations = {
+	.lookup		= eventfs_root_lookup,
+};
+
+static const struct file_operations eventfs_file_operations = {
+	.open		= dcache_dir_open_wrapper,
+	.read		= generic_read_dir,
+	.iterate_shared	= dcache_readdir,
+	.llseek		= generic_file_llseek,
+	.release	= eventfs_release,
+};
+
+/**
+ * create_file - create a file in the tracefs filesystem
+ * @name: the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: parent dentry for this file.
+ * @data: something that the caller will want to get to later on.
+ * @fop: struct file_operations that should be used for this file.
+ *
+ * This is the basic "create a file" function for tracefs.  It allows for a
+ * wide range of flexibility in creating a file.
+ *
+ * This function will return a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the tracefs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here.)  If an error occurs, %NULL will be returned.
+ *
+ * If tracefs is not enabled in the kernel, the value -%ENODEV will be
+ * returned.
+ */
+static struct dentry *create_file(const char *name, umode_t mode,
+				  struct dentry *parent, void *data,
+				  const struct file_operations *fop)
+{
+	struct tracefs_inode *ti;
+	struct dentry *dentry;
+	struct inode *inode;
+
+	if (!(mode & S_IFMT))
+		mode |= S_IFREG;
+
+	if (WARN_ON_ONCE(!S_ISREG(mode)))
+		return NULL;
+
+	dentry = eventfs_start_creating(name, parent);
+
+	if (IS_ERR(dentry))
+		return dentry;
+
+	inode = tracefs_get_inode(dentry->d_sb);
+	if (unlikely(!inode))
+		return eventfs_failed_creating(dentry);
+
+	inode->i_mode = mode;
+	inode->i_fop = fop;
+	inode->i_private = data;
+
+	ti = get_tracefs(inode);
+	ti->flags |= TRACEFS_EVENT_INODE;
+	d_instantiate(dentry, inode);
+	fsnotify_create(dentry->d_parent->d_inode, dentry);
+	return eventfs_end_creating(dentry);
+};
+
+/**
+ * create_dir - create a dir in the tracefs filesystem
+ * @name: the name of the file to create.
+ * @parent: parent dentry for this file.
+ * @data: something that the caller will want to get to later on.
+ *
+ * This is the basic "create a dir" function for eventfs.  It allows for a
+ * wide range of flexibility in creating a dir.
+ *
+ * This function will return a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the tracefs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here.)  If an error occurs, %NULL will be returned.
+ *
+ * If tracefs is not enabled in the kernel, the value -%ENODEV will be
+ * returned.
+ */
+static struct dentry *create_dir(const char *name, struct dentry *parent, void *data)
+{
+	struct tracefs_inode *ti;
+	struct dentry *dentry;
+	struct inode *inode;
+
+	dentry = eventfs_start_creating(name, parent);
+	if (IS_ERR(dentry))
+		return dentry;
+
+	inode = tracefs_get_inode(dentry->d_sb);
+	if (unlikely(!inode))
+		return eventfs_failed_creating(dentry);
+
+	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+	inode->i_op = &eventfs_root_dir_inode_operations;
+	inode->i_fop = &eventfs_file_operations;
+	inode->i_private = data;
+
+	ti = get_tracefs(inode);
+	ti->flags |= TRACEFS_EVENT_INODE;
+
+	inc_nlink(inode);
+	d_instantiate(dentry, inode);
+	inc_nlink(dentry->d_parent->d_inode);
+	fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
+	return eventfs_end_creating(dentry);
+}
+
+/**
+ * eventfs_set_ef_status_free - set the ef->status to free
+ * @dentry: dentry who's status to be freed
+ *
+ * eventfs_set_ef_status_free will be called if no more
+ * references remain
+ */
+void eventfs_set_ef_status_free(struct dentry *dentry)
+{
+	struct tracefs_inode *ti_parent;
+	struct eventfs_file *ef;
+
+	mutex_lock(&eventfs_mutex);
+	ti_parent = get_tracefs(dentry->d_parent->d_inode);
+	if (!ti_parent || !(ti_parent->flags & TRACEFS_EVENT_INODE))
+		goto out;
+
+	ef = dentry->d_fsdata;
+	if (!ef)
+		goto out;
+
+	/*
+	 * If ef was freed, then the LSB bit is set for d_fsdata.
+	 * But this should not happen, as it should still have a
+	 * ref count that prevents it. Warn in case it does.
+	 */
+	if (WARN_ON_ONCE((unsigned long)ef & 1))
+		goto out;
+
+	dentry->d_fsdata = NULL;
+	ef->dentry = NULL;
+out:
+	mutex_unlock(&eventfs_mutex);
+}
+
+/**
+ * eventfs_post_create_dir - post create dir routine
+ * @ef: eventfs_file of recently created dir
+ *
+ * Map the meta-data of files within an eventfs dir to their parent dentry
+ */
+static void eventfs_post_create_dir(struct eventfs_file *ef)
+{
+	struct eventfs_file *ef_child;
+	struct tracefs_inode *ti;
+
+	/* srcu lock already held */
+	/* fill parent-child relation */
+	list_for_each_entry_srcu(ef_child, &ef->ei->e_top_files, list,
+				 srcu_read_lock_held(&eventfs_srcu)) {
+		ef_child->d_parent = ef->dentry;
+	}
+
+	ti = get_tracefs(ef->dentry->d_inode);
+	ti->private = ef->ei;
+}
+
+/**
+ * create_dentry - helper function to create dentry
+ * @ef: eventfs_file of file or directory to create
+ * @parent: parent dentry
+ * @lookup: true if called from lookup routine
+ *
+ * Used to create a dentry for file/dir, executes post dentry creation routine
+ */
+static struct dentry *
+create_dentry(struct eventfs_file *ef, struct dentry *parent, bool lookup)
+{
+	bool invalidate = false;
+	struct dentry *dentry;
+
+	mutex_lock(&eventfs_mutex);
+	if (ef->is_freed) {
+		mutex_unlock(&eventfs_mutex);
+		return NULL;
+	}
+	if (ef->dentry) {
+		dentry = ef->dentry;
+		/* On dir open, up the ref count */
+		if (!lookup)
+			dget(dentry);
+		mutex_unlock(&eventfs_mutex);
+		return dentry;
+	}
+	mutex_unlock(&eventfs_mutex);
+
+	if (!lookup)
+		inode_lock(parent->d_inode);
+
+	if (ef->ei)
+		dentry = create_dir(ef->name, parent, ef->data);
+	else
+		dentry = create_file(ef->name, ef->mode, parent,
+				     ef->data, ef->fop);
+
+	if (!lookup)
+		inode_unlock(parent->d_inode);
+
+	mutex_lock(&eventfs_mutex);
+	if (IS_ERR_OR_NULL(dentry)) {
+		/* If the ef was already updated get it */
+		dentry = ef->dentry;
+		if (dentry && !lookup)
+			dget(dentry);
+		mutex_unlock(&eventfs_mutex);
+		return dentry;
+	}
+
+	if (!ef->dentry && !ef->is_freed) {
+		ef->dentry = dentry;
+		if (ef->ei)
+			eventfs_post_create_dir(ef);
+		dentry->d_fsdata = ef;
+	} else {
+		/* A race here, should try again (unless freed) */
+		invalidate = true;
+
+		/*
+		 * Should never happen unless we get here due to being freed.
+		 * Otherwise it means two dentries exist with the same name.
+		 */
+		WARN_ON_ONCE(!ef->is_freed);
+	}
+	mutex_unlock(&eventfs_mutex);
+	if (invalidate)
+		d_invalidate(dentry);
+
+	if (lookup || invalidate)
+		dput(dentry);
+
+	return invalidate ? NULL : dentry;
+}
+
+static bool match_event_file(struct eventfs_file *ef, const char *name)
+{
+	bool ret;
+
+	mutex_lock(&eventfs_mutex);
+	ret = !ef->is_freed && strcmp(ef->name, name) == 0;
+	mutex_unlock(&eventfs_mutex);
+
+	return ret;
+}
+
+/**
+ * eventfs_root_lookup - lookup routine to create file/dir
+ * @dir: in which a lookup is being done
+ * @dentry: file/dir dentry
+ * @flags: to pass as flags parameter to simple lookup
+ *
+ * Used to create a dynamic file/dir within @dir. Use the eventfs_inode
+ * list of meta data to find the information needed to create the file/dir.
+ */
+static struct dentry *eventfs_root_lookup(struct inode *dir,
+					  struct dentry *dentry,
+					  unsigned int flags)
+{
+	struct tracefs_inode *ti;
+	struct eventfs_inode *ei;
+	struct eventfs_file *ef;
+	struct dentry *ret = NULL;
+	int idx;
+
+	ti = get_tracefs(dir);
+	if (!(ti->flags & TRACEFS_EVENT_INODE))
+		return NULL;
+
+	ei = ti->private;
+	idx = srcu_read_lock(&eventfs_srcu);
+	list_for_each_entry_srcu(ef, &ei->e_top_files, list,
+				 srcu_read_lock_held(&eventfs_srcu)) {
+		if (!match_event_file(ef, dentry->d_name.name))
+			continue;
+		ret = simple_lookup(dir, dentry, flags);
+		create_dentry(ef, ef->d_parent, true);
+		break;
+	}
+	srcu_read_unlock(&eventfs_srcu, idx);
+	return ret;
+}
+
+/**
+ * eventfs_release - called to release eventfs file/dir
+ * @inode: inode to be released
+ * @file: file to be released (not used)
+ */
+static int eventfs_release(struct inode *inode, struct file *file)
+{
+	struct tracefs_inode *ti;
+	struct eventfs_inode *ei;
+	struct eventfs_file *ef;
+	struct dentry *dentry;
+	int idx;
+
+	ti = get_tracefs(inode);
+	if (!(ti->flags & TRACEFS_EVENT_INODE))
+		return -EINVAL;
+
+	ei = ti->private;
+	idx = srcu_read_lock(&eventfs_srcu);
+	list_for_each_entry_srcu(ef, &ei->e_top_files, list,
+				 srcu_read_lock_held(&eventfs_srcu)) {
+		mutex_lock(&eventfs_mutex);
+		dentry = ef->dentry;
+		mutex_unlock(&eventfs_mutex);
+		if (dentry)
+			dput(dentry);
+	}
+	srcu_read_unlock(&eventfs_srcu, idx);
+	return dcache_dir_close(inode, file);
+}
+
+/**
+ * dcache_dir_open_wrapper - eventfs open wrapper
+ * @inode: not used
+ * @file: dir to be opened (to create its child)
+ *
+ * Used to dynamically create the file/dir within @file. @file is really a
+ * directory and all the files/dirs of the children within @file will be
+ * created. If any of the files/dirs have already been created, their
+ * reference count will be incremented.
+ */
+static int dcache_dir_open_wrapper(struct inode *inode, struct file *file)
+{
+	struct tracefs_inode *ti;
+	struct eventfs_inode *ei;
+	struct eventfs_file *ef;
+	struct dentry *dentry = file_dentry(file);
+	struct inode *f_inode = file_inode(file);
+	int idx;
+
+	ti = get_tracefs(f_inode);
+	if (!(ti->flags & TRACEFS_EVENT_INODE))
+		return -EINVAL;
+
+	ei = ti->private;
+	idx = srcu_read_lock(&eventfs_srcu);
+	list_for_each_entry_rcu(ef, &ei->e_top_files, list) {
+		create_dentry(ef, dentry, false);
+	}
+	srcu_read_unlock(&eventfs_srcu, idx);
+	return dcache_dir_open(inode, file);
+}
+
+/**
+ * eventfs_prepare_ef - helper function to prepare eventfs_file
+ * @name: the name of the file/directory to create.
+ * @mode: the permission that the file should have.
+ * @fop: struct file_operations that should be used for this file/directory.
+ * @iop: struct inode_operations that should be used for this file/directory.
+ * @data: something that the caller will want to get to later on. The
+ *        inode.i_private pointer will point to this value on the open() call.
+ *
+ * This function allocates and fills the eventfs_file structure.
+ */
+static struct eventfs_file *eventfs_prepare_ef(const char *name, umode_t mode,
+					const struct file_operations *fop,
+					const struct inode_operations *iop,
+					void *data)
+{
+	struct eventfs_file *ef;
+
+	ef = kzalloc(sizeof(*ef), GFP_KERNEL);
+	if (!ef)
+		return ERR_PTR(-ENOMEM);
+
+	ef->name = kstrdup(name, GFP_KERNEL);
+	if (!ef->name) {
+		kfree(ef);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	if (S_ISDIR(mode)) {
+		ef->ei = kzalloc(sizeof(*ef->ei), GFP_KERNEL);
+		if (!ef->ei) {
+			kfree(ef->name);
+			kfree(ef);
+			return ERR_PTR(-ENOMEM);
+		}
+		INIT_LIST_HEAD(&ef->ei->e_top_files);
+	} else {
+		ef->ei = NULL;
+	}
+
+	ef->iop = iop;
+	ef->fop = fop;
+	ef->mode = mode;
+	ef->data = data;
+	return ef;
+}
+
+/**
+ * eventfs_create_events_dir - create the trace event structure
+ * @name: the name of the directory to create.
+ * @parent: parent dentry for this file.  This should be a directory dentry
+ *          if set.  If this parameter is NULL, then the directory will be
+ *          created in the root of the tracefs filesystem.
+ *
+ * This function creates the top of the trace event directory.
+ */
+struct dentry *eventfs_create_events_dir(const char *name,
+					 struct dentry *parent)
+{
+	struct dentry *dentry = tracefs_start_creating(name, parent);
+	struct eventfs_inode *ei;
+	struct tracefs_inode *ti;
+	struct inode *inode;
+
+	if (IS_ERR(dentry))
+		return dentry;
+
+	ei = kzalloc(sizeof(*ei), GFP_KERNEL);
+	if (!ei)
+		return ERR_PTR(-ENOMEM);
+	inode = tracefs_get_inode(dentry->d_sb);
+	if (unlikely(!inode)) {
+		kfree(ei);
+		tracefs_failed_creating(dentry);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	INIT_LIST_HEAD(&ei->e_top_files);
+
+	ti = get_tracefs(inode);
+	ti->flags |= TRACEFS_EVENT_INODE;
+	ti->private = ei;
+
+	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+	inode->i_op = &eventfs_root_dir_inode_operations;
+	inode->i_fop = &eventfs_file_operations;
+
+	/* directory inodes start off with i_nlink == 2 (for "." entry) */
+	inc_nlink(inode);
+	d_instantiate(dentry, inode);
+	inc_nlink(dentry->d_parent->d_inode);
+	fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
+	return tracefs_end_creating(dentry);
+}
+
+/**
+ * eventfs_add_subsystem_dir - add eventfs subsystem_dir to list to create later
+ * @name: the name of the file to create.
+ * @parent: parent dentry for this dir.
+ *
+ * This function adds eventfs subsystem dir to list.
+ * And all these dirs are created on the fly when they are looked up,
+ * and the dentry and inodes will be removed when they are done.
+ */
+struct eventfs_file *eventfs_add_subsystem_dir(const char *name,
+					       struct dentry *parent)
+{
+	struct tracefs_inode *ti_parent;
+	struct eventfs_inode *ei_parent;
+	struct eventfs_file *ef;
+
+	if (!parent)
+		return ERR_PTR(-EINVAL);
+
+	ti_parent = get_tracefs(parent->d_inode);
+	ei_parent = ti_parent->private;
+
+	ef = eventfs_prepare_ef(name, S_IFDIR, NULL, NULL, NULL);
+	if (IS_ERR(ef))
+		return ef;
+
+	mutex_lock(&eventfs_mutex);
+	list_add_tail(&ef->list, &ei_parent->e_top_files);
+	ef->d_parent = parent;
+	mutex_unlock(&eventfs_mutex);
+	return ef;
+}
+
+/**
+ * eventfs_add_dir - add eventfs dir to list to create later
+ * @name: the name of the file to create.
+ * @ef_parent: parent eventfs_file for this dir.
+ *
+ * This function adds eventfs dir to list.
+ * And all these dirs are created on the fly when they are looked up,
+ * and the dentry and inodes will be removed when they are done.
+ */
+struct eventfs_file *eventfs_add_dir(const char *name,
+				     struct eventfs_file *ef_parent)
+{
+	struct eventfs_file *ef;
+
+	if (!ef_parent)
+		return ERR_PTR(-EINVAL);
+
+	ef = eventfs_prepare_ef(name, S_IFDIR, NULL, NULL, NULL);
+	if (IS_ERR(ef))
+		return ef;
+
+	mutex_lock(&eventfs_mutex);
+	list_add_tail(&ef->list, &ef_parent->ei->e_top_files);
+	ef->d_parent = ef_parent->dentry;
+	mutex_unlock(&eventfs_mutex);
+	return ef;
+}
+
+/**
+ * eventfs_add_events_file - add the data needed to create a file for later reference
+ * @name: the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: parent dentry for this file.
+ * @data: something that the caller will want to get to later on.
+ * @fop: struct file_operations that should be used for this file.
+ *
+ * This function is used to add the information needed to create a
+ * dentry/inode within the top level events directory. The file created
+ * will have the @mode permissions. The @data will be used to fill the
+ * inode.i_private when the open() call is done. The dentry and inodes are
+ * all created when they are referenced, and removed when they are no
+ * longer referenced.
+ */
+int eventfs_add_events_file(const char *name, umode_t mode,
+			 struct dentry *parent, void *data,
+			 const struct file_operations *fop)
+{
+	struct tracefs_inode *ti;
+	struct eventfs_inode *ei;
+	struct eventfs_file *ef;
+
+	if (!parent)
+		return -EINVAL;
+
+	if (!(mode & S_IFMT))
+		mode |= S_IFREG;
+
+	if (!parent->d_inode)
+		return -EINVAL;
+
+	ti = get_tracefs(parent->d_inode);
+	if (!(ti->flags & TRACEFS_EVENT_INODE))
+		return -EINVAL;
+
+	ei = ti->private;
+	ef = eventfs_prepare_ef(name, mode, fop, NULL, data);
+
+	if (IS_ERR(ef))
+		return -ENOMEM;
+
+	mutex_lock(&eventfs_mutex);
+	list_add_tail(&ef->list, &ei->e_top_files);
+	ef->d_parent = parent;
+	mutex_unlock(&eventfs_mutex);
+	return 0;
+}
+
+/**
+ * eventfs_add_file - add eventfs file to list to create later
+ * @name: the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @ef_parent: parent eventfs_file for this file.
+ * @data: something that the caller will want to get to later on.
+ * @fop: struct file_operations that should be used for this file.
+ *
+ * This function is used to add the information needed to create a
+ * file within a subdirectory of the events directory. The file created
+ * will have the @mode permissions. The @data will be used to fill the
+ * inode.i_private when the open() call is done. The dentry and inodes are
+ * all created when they are referenced, and removed when they are no
+ * longer referenced.
+ */
+int eventfs_add_file(const char *name, umode_t mode,
+		     struct eventfs_file *ef_parent,
+		     void *data,
+		     const struct file_operations *fop)
+{
+	struct eventfs_file *ef;
+
+	if (!ef_parent)
+		return -EINVAL;
+
+	if (!(mode & S_IFMT))
+		mode |= S_IFREG;
+
+	ef = eventfs_prepare_ef(name, mode, fop, NULL, data);
+	if (IS_ERR(ef))
+		return -ENOMEM;
+
+	mutex_lock(&eventfs_mutex);
+	list_add_tail(&ef->list, &ef_parent->ei->e_top_files);
+	ef->d_parent = ef_parent->dentry;
+	mutex_unlock(&eventfs_mutex);
+	return 0;
+}
+
+static void free_ef(struct rcu_head *head)
+{
+	struct eventfs_file *ef = container_of(head, struct eventfs_file, rcu);
+
+	kfree(ef->name);
+	kfree(ef->ei);
+	kfree(ef);
+}
+
+/**
+ * eventfs_remove_rec - remove eventfs dir or file from list
+ * @ef: eventfs_file to be removed.
+ * @head: to create list of eventfs_file to be deleted
+ * @level: to check recursion depth
+ *
+ * The helper function eventfs_remove_rec() is used to clean up and free the
+ * associated data from eventfs for both of the added functions.
+ */
+static void eventfs_remove_rec(struct eventfs_file *ef, struct list_head *head, int level)
+{
+	struct eventfs_file *ef_child;
+
+	if (!ef)
+		return;
+	/*
+	 * Check recursion depth. It should never be greater than 3:
+	 * 0 - events/
+	 * 1 - events/group/
+	 * 2 - events/group/event/
+	 * 3 - events/group/event/file
+	 */
+	if (WARN_ON_ONCE(level > 3))
+		return;
+
+	if (ef->ei) {
+		/* search for nested folders or files */
+		list_for_each_entry_srcu(ef_child, &ef->ei->e_top_files, list,
+					 lockdep_is_held(&eventfs_mutex)) {
+			eventfs_remove_rec(ef_child, head, level + 1);
+		}
+	}
+
+	list_del_rcu(&ef->list);
+	list_add_tail(&ef->del_list, head);
+}
+
+/**
+ * eventfs_remove - remove eventfs dir or file from list
+ * @ef: eventfs_file to be removed.
+ *
+ * This function acquire the eventfs_mutex lock and call eventfs_remove_rec()
+ */
+void eventfs_remove(struct eventfs_file *ef)
+{
+	struct eventfs_file *tmp;
+	LIST_HEAD(ef_del_list);
+	struct dentry *dentry_list = NULL;
+	struct dentry *dentry;
+
+	if (!ef)
+		return;
+
+	mutex_lock(&eventfs_mutex);
+	eventfs_remove_rec(ef, &ef_del_list, 0);
+	list_for_each_entry_safe(ef, tmp, &ef_del_list, del_list) {
+		if (ef->dentry) {
+			unsigned long ptr = (unsigned long)dentry_list;
+
+			/* Keep the dentry from being freed yet */
+			dget(ef->dentry);
+
+			/*
+			 * Paranoid: The dget() above should prevent the dentry
+			 * from being freed and calling eventfs_set_ef_status_free().
+			 * But just in case, set the link list LSB pointer to 1
+			 * and have eventfs_set_ef_status_free() check that to
+			 * make sure that if it does happen, it will not think
+			 * the d_fsdata is an event_file.
+			 *
+			 * For this to work, no event_file should be allocated
+			 * on a odd space, as the ef should always be allocated
+			 * to be at least word aligned. Check for that too.
+			 */
+			WARN_ON_ONCE(ptr & 1);
+
+			ef->dentry->d_fsdata = (void *)(ptr | 1);
+			dentry_list = ef->dentry;
+			ef->dentry = NULL;
+		}
+		call_srcu(&eventfs_srcu, &ef->rcu, free_ef);
+	}
+	mutex_unlock(&eventfs_mutex);
+
+	while (dentry_list) {
+		unsigned long ptr;
+
+		dentry = dentry_list;
+		ptr = (unsigned long)dentry->d_fsdata & ~1UL;
+		dentry_list = (struct dentry *)ptr;
+		dentry->d_fsdata = NULL;
+		d_invalidate(dentry);
+		mutex_lock(&eventfs_mutex);
+		/* dentry should now have at least a single reference */
+		WARN_ONCE((int)d_count(dentry) < 1,
+			  "dentry %p less than one reference (%d) after invalidate\n",
+			  dentry, d_count(dentry));
+		mutex_unlock(&eventfs_mutex);
+		dput(dentry);
+	}
+}
+
+/**
+ * eventfs_remove_events_dir - remove eventfs dir or file from list
+ * @dentry: events's dentry to be removed.
+ *
+ * This function remove events main directory
+ */
+void eventfs_remove_events_dir(struct dentry *dentry)
+{
+	struct tracefs_inode *ti;
+	struct eventfs_inode *ei;
+
+	if (!dentry || !dentry->d_inode)
+		return;
+
+	ti = get_tracefs(dentry->d_inode);
+	if (!ti || !(ti->flags & TRACEFS_EVENT_INODE))
+		return;
+
+	ei = ti->private;
+	d_invalidate(dentry);
+	dput(dentry);
+	kfree(ei);
+}
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 2feb6c5..de5b722 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -21,13 +21,33 @@
 #include <linux/parser.h>
 #include <linux/magic.h>
 #include <linux/slab.h>
+#include "internal.h"
 
 #define TRACEFS_DEFAULT_MODE	0700
+static struct kmem_cache *tracefs_inode_cachep __ro_after_init;
 
 static struct vfsmount *tracefs_mount;
 static int tracefs_mount_count;
 static bool tracefs_registered;
 
+static struct inode *tracefs_alloc_inode(struct super_block *sb)
+{
+	struct tracefs_inode *ti;
+
+	ti = kmem_cache_alloc(tracefs_inode_cachep, GFP_KERNEL);
+	if (!ti)
+		return NULL;
+
+	ti->flags = 0;
+
+	return &ti->vfs_inode;
+}
+
+static void tracefs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(tracefs_inode_cachep, get_tracefs(inode));
+}
+
 static ssize_t default_read_file(struct file *file, char __user *buf,
 				 size_t count, loff_t *ppos)
 {
@@ -127,7 +147,7 @@ static const struct inode_operations tracefs_dir_inode_operations = {
 	.rmdir		= tracefs_syscall_rmdir,
 };
 
-static struct inode *tracefs_get_inode(struct super_block *sb)
+struct inode *tracefs_get_inode(struct super_block *sb)
 {
 	struct inode *inode = new_inode(sb);
 	if (inode) {
@@ -290,6 +310,7 @@ static int tracefs_apply_options(struct super_block *sb, bool remount)
 	struct tracefs_fs_info *fsi = sb->s_fs_info;
 	struct inode *inode = d_inode(sb->s_root);
 	struct tracefs_mount_opts *opts = &fsi->mount_opts;
+	umode_t tmp_mode;
 
 	/*
 	 * On remount, only reset mode/uid/gid if they were provided as mount
@@ -297,8 +318,9 @@ static int tracefs_apply_options(struct super_block *sb, bool remount)
 	 */
 
 	if (!remount || opts->opts & BIT(Opt_mode)) {
-		inode->i_mode &= ~S_IALLUGO;
-		inode->i_mode |= opts->mode;
+		tmp_mode = READ_ONCE(inode->i_mode) & ~S_IALLUGO;
+		tmp_mode |= opts->mode;
+		WRITE_ONCE(inode->i_mode, tmp_mode);
 	}
 
 	if (!remount || opts->opts & BIT(Opt_uid))
@@ -346,11 +368,31 @@ static int tracefs_show_options(struct seq_file *m, struct dentry *root)
 }
 
 static const struct super_operations tracefs_super_operations = {
+	.alloc_inode    = tracefs_alloc_inode,
+	.free_inode     = tracefs_free_inode,
+	.drop_inode     = generic_delete_inode,
 	.statfs		= simple_statfs,
 	.remount_fs	= tracefs_remount,
 	.show_options	= tracefs_show_options,
 };
 
+static void tracefs_dentry_iput(struct dentry *dentry, struct inode *inode)
+{
+	struct tracefs_inode *ti;
+
+	if (!dentry || !inode)
+		return;
+
+	ti = get_tracefs(inode);
+	if (ti && ti->flags & TRACEFS_EVENT_INODE)
+		eventfs_set_ef_status_free(dentry);
+	iput(inode);
+}
+
+static const struct dentry_operations tracefs_dentry_operations = {
+	.d_iput = tracefs_dentry_iput,
+};
+
 static int trace_fill_super(struct super_block *sb, void *data, int silent)
 {
 	static const struct tree_descr trace_files[] = {{""}};
@@ -373,6 +415,7 @@ static int trace_fill_super(struct super_block *sb, void *data, int silent)
 		goto fail;
 
 	sb->s_op = &tracefs_super_operations;
+	sb->s_d_op = &tracefs_dentry_operations;
 
 	tracefs_apply_options(sb, false);
 
@@ -399,7 +442,7 @@ static struct file_system_type trace_fs_type = {
 };
 MODULE_ALIAS_FS("tracefs");
 
-static struct dentry *start_creating(const char *name, struct dentry *parent)
+struct dentry *tracefs_start_creating(const char *name, struct dentry *parent)
 {
 	struct dentry *dentry;
 	int error;
@@ -437,7 +480,7 @@ static struct dentry *start_creating(const char *name, struct dentry *parent)
 	return dentry;
 }
 
-static struct dentry *failed_creating(struct dentry *dentry)
+struct dentry *tracefs_failed_creating(struct dentry *dentry)
 {
 	inode_unlock(d_inode(dentry->d_parent));
 	dput(dentry);
@@ -445,13 +488,87 @@ static struct dentry *failed_creating(struct dentry *dentry)
 	return NULL;
 }
 
-static struct dentry *end_creating(struct dentry *dentry)
+struct dentry *tracefs_end_creating(struct dentry *dentry)
 {
 	inode_unlock(d_inode(dentry->d_parent));
 	return dentry;
 }
 
 /**
+ * eventfs_start_creating - start the process of creating a dentry
+ * @name: Name of the file created for the dentry
+ * @parent: The parent dentry where this dentry will be created
+ *
+ * This is a simple helper function for the dynamically created eventfs
+ * files. When the directory of the eventfs files are accessed, their
+ * dentries are created on the fly. This function is used to start that
+ * process.
+ */
+struct dentry *eventfs_start_creating(const char *name, struct dentry *parent)
+{
+	struct dentry *dentry;
+	int error;
+
+	error = simple_pin_fs(&trace_fs_type, &tracefs_mount,
+			      &tracefs_mount_count);
+	if (error)
+		return ERR_PTR(error);
+
+	/*
+	 * If the parent is not specified, we create it in the root.
+	 * We need the root dentry to do this, which is in the super
+	 * block. A pointer to that is in the struct vfsmount that we
+	 * have around.
+	 */
+	if (!parent)
+		parent = tracefs_mount->mnt_root;
+
+	if (unlikely(IS_DEADDIR(parent->d_inode)))
+		dentry = ERR_PTR(-ENOENT);
+	else
+		dentry = lookup_one_len(name, parent, strlen(name));
+
+	if (!IS_ERR(dentry) && dentry->d_inode) {
+		dput(dentry);
+		dentry = ERR_PTR(-EEXIST);
+	}
+
+	if (IS_ERR(dentry))
+		simple_release_fs(&tracefs_mount, &tracefs_mount_count);
+
+	return dentry;
+}
+
+/**
+ * eventfs_failed_creating - clean up a failed eventfs dentry creation
+ * @dentry: The dentry to clean up
+ *
+ * If after calling eventfs_start_creating(), a failure is detected, the
+ * resources created by eventfs_start_creating() needs to be cleaned up. In
+ * that case, this function should be called to perform that clean up.
+ */
+struct dentry *eventfs_failed_creating(struct dentry *dentry)
+{
+	dput(dentry);
+	simple_release_fs(&tracefs_mount, &tracefs_mount_count);
+	return NULL;
+}
+
+/**
+ * eventfs_end_creating - Finish the process of creating a eventfs dentry
+ * @dentry: The dentry that has successfully been created.
+ *
+ * This function is currently just a place holder to match
+ * eventfs_start_creating(). In case any synchronization needs to be added,
+ * this function will be used to implement that without having to modify
+ * the callers of eventfs_start_creating().
+ */
+struct dentry *eventfs_end_creating(struct dentry *dentry)
+{
+	return dentry;
+}
+
+/**
  * tracefs_create_file - create a file in the tracefs filesystem
  * @name: a pointer to a string containing the name of the file to create.
  * @mode: the permission that the file should have.
@@ -490,14 +607,14 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
 	if (!(mode & S_IFMT))
 		mode |= S_IFREG;
 	BUG_ON(!S_ISREG(mode));
-	dentry = start_creating(name, parent);
+	dentry = tracefs_start_creating(name, parent);
 
 	if (IS_ERR(dentry))
 		return NULL;
 
 	inode = tracefs_get_inode(dentry->d_sb);
 	if (unlikely(!inode))
-		return failed_creating(dentry);
+		return tracefs_failed_creating(dentry);
 
 	inode->i_mode = mode;
 	inode->i_fop = fops ? fops : &tracefs_file_operations;
@@ -506,13 +623,13 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode,
 	inode->i_gid = d_inode(dentry->d_parent)->i_gid;
 	d_instantiate(dentry, inode);
 	fsnotify_create(d_inode(dentry->d_parent), dentry);
-	return end_creating(dentry);
+	return tracefs_end_creating(dentry);
 }
 
 static struct dentry *__create_dir(const char *name, struct dentry *parent,
 				   const struct inode_operations *ops)
 {
-	struct dentry *dentry = start_creating(name, parent);
+	struct dentry *dentry = tracefs_start_creating(name, parent);
 	struct inode *inode;
 
 	if (IS_ERR(dentry))
@@ -520,7 +637,7 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent,
 
 	inode = tracefs_get_inode(dentry->d_sb);
 	if (unlikely(!inode))
-		return failed_creating(dentry);
+		return tracefs_failed_creating(dentry);
 
 	/* Do not set bits for OTH */
 	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUSR| S_IRGRP | S_IXUSR | S_IXGRP;
@@ -534,7 +651,7 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent,
 	d_instantiate(dentry, inode);
 	inc_nlink(d_inode(dentry->d_parent));
 	fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
-	return end_creating(dentry);
+	return tracefs_end_creating(dentry);
 }
 
 /**
@@ -628,10 +745,26 @@ bool tracefs_initialized(void)
 	return tracefs_registered;
 }
 
+static void init_once(void *foo)
+{
+	struct tracefs_inode *ti = (struct tracefs_inode *) foo;
+
+	inode_init_once(&ti->vfs_inode);
+}
+
 static int __init tracefs_init(void)
 {
 	int retval;
 
+	tracefs_inode_cachep = kmem_cache_create("tracefs_inode_cache",
+						 sizeof(struct tracefs_inode),
+						 0, (SLAB_RECLAIM_ACCOUNT|
+						     SLAB_MEM_SPREAD|
+						     SLAB_ACCOUNT),
+						 init_once);
+	if (!tracefs_inode_cachep)
+		return -ENOMEM;
+
 	retval = sysfs_create_mount_point(kernel_kobj, "tracing");
 	if (retval)
 		return -EINVAL;
diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h
new file mode 100644
index 0000000..69c2b1d
--- /dev/null
+++ b/fs/tracefs/internal.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TRACEFS_INTERNAL_H
+#define _TRACEFS_INTERNAL_H
+
+enum {
+	TRACEFS_EVENT_INODE     = BIT(1),
+};
+
+struct tracefs_inode {
+	unsigned long           flags;
+	void                    *private;
+	struct inode            vfs_inode;
+};
+
+static inline struct tracefs_inode *get_tracefs(const struct inode *inode)
+{
+	return container_of(inode, struct tracefs_inode, vfs_inode);
+}
+
+struct dentry *tracefs_start_creating(const char *name, struct dentry *parent);
+struct dentry *tracefs_end_creating(struct dentry *dentry);
+struct dentry *tracefs_failed_creating(struct dentry *dentry);
+struct inode *tracefs_get_inode(struct super_block *sb);
+struct dentry *eventfs_start_creating(const char *name, struct dentry *parent);
+struct dentry *eventfs_failed_creating(struct dentry *dentry);
+struct dentry *eventfs_end_creating(struct dentry *dentry);
+void eventfs_set_ef_status_free(struct dentry *dentry);
+
+#endif /* _TRACEFS_INTERNAL_H */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index aad9cf8..e892187 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -862,13 +862,8 @@ extern int skip_trace(unsigned long ip);
 extern void ftrace_module_init(struct module *mod);
 extern void ftrace_module_enable(struct module *mod);
 extern void ftrace_release_mod(struct module *mod);
-
-extern void ftrace_disable_daemon(void);
-extern void ftrace_enable_daemon(void);
 #else /* CONFIG_DYNAMIC_FTRACE */
 static inline int skip_trace(unsigned long ip) { return 0; }
-static inline void ftrace_disable_daemon(void) { }
-static inline void ftrace_enable_daemon(void) { }
 static inline void ftrace_module_init(struct module *mod) { }
 static inline void ftrace_module_enable(struct module *mod) { }
 static inline void ftrace_release_mod(struct module *mod) { }
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index c1a0a19..eb5c3ad 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -649,6 +649,7 @@ struct trace_event_file {
 	struct list_head		list;
 	struct trace_event_call		*event_call;
 	struct event_filter __rcu	*filter;
+	struct eventfs_file             *ef;
 	struct dentry			*dir;
 	struct trace_array		*tr;
 	struct trace_subsystem_dir	*system;
@@ -824,6 +825,7 @@ enum {
 	FILTER_RDYN_STRING,
 	FILTER_PTR_STRING,
 	FILTER_TRACE_FN,
+	FILTER_CPUMASK,
 	FILTER_COMM,
 	FILTER_CPU,
 	FILTER_STACKTRACE,
diff --git a/include/linux/tracefs.h b/include/linux/tracefs.h
index 9991244..0090727 100644
--- a/include/linux/tracefs.h
+++ b/include/linux/tracefs.h
@@ -21,6 +21,29 @@ struct file_operations;
 
 #ifdef CONFIG_TRACING
 
+struct eventfs_file;
+
+struct dentry *eventfs_create_events_dir(const char *name,
+					 struct dentry *parent);
+
+struct eventfs_file *eventfs_add_subsystem_dir(const char *name,
+					       struct dentry *parent);
+
+struct eventfs_file *eventfs_add_dir(const char *name,
+				     struct eventfs_file *ef_parent);
+
+int eventfs_add_file(const char *name, umode_t mode,
+		     struct eventfs_file *ef_parent, void *data,
+		     const struct file_operations *fops);
+
+int eventfs_add_events_file(const char *name, umode_t mode,
+			 struct dentry *parent, void *data,
+			 const struct file_operations *fops);
+
+void eventfs_remove(struct eventfs_file *ef);
+
+void eventfs_remove_events_dir(struct dentry *dentry);
+
 struct dentry *tracefs_create_file(const char *name, umode_t mode,
 				   struct dentry *parent, void *data,
 				   const struct file_operations *fops);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 52dea5d..78502d4 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -692,10 +692,7 @@ static void rb_time_set(rb_time_t *t, u64 val)
 static inline bool
 rb_time_read_cmpxchg(local_t *l, unsigned long expect, unsigned long set)
 {
-	unsigned long ret;
-
-	ret = local_cmpxchg(l, expect, set);
-	return ret == expect;
+	return local_try_cmpxchg(l, &expect, set);
 }
 
 static bool rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
@@ -752,9 +749,7 @@ static void rb_time_set(rb_time_t *t, u64 val)
 
 static bool rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
 {
-	u64 val;
-	val = local64_cmpxchg(&t->time, expect, set);
-	return val == expect;
+	return local64_try_cmpxchg(&t->time, &expect, set);
 }
 #endif
 
@@ -1494,14 +1489,11 @@ static bool rb_head_page_replace(struct buffer_page *old,
 {
 	unsigned long *ptr = (unsigned long *)&old->list.prev->next;
 	unsigned long val;
-	unsigned long ret;
 
 	val = *ptr & ~RB_FLAG_MASK;
 	val |= RB_PAGE_HEAD;
 
-	ret = cmpxchg(ptr, val, (unsigned long)&new->list);
-
-	return ret == val;
+	return try_cmpxchg(ptr, &val, (unsigned long)&new->list);
 }
 
 /*
@@ -3003,7 +2995,6 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
 {
 	unsigned long new_index, old_index;
 	struct buffer_page *bpage;
-	unsigned long index;
 	unsigned long addr;
 	u64 write_stamp;
 	u64 delta;
@@ -3060,8 +3051,9 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
 		 */
 		old_index += write_mask;
 		new_index += write_mask;
-		index = local_cmpxchg(&bpage->write, old_index, new_index);
-		if (index == old_index) {
+
+		/* caution: old_index gets updated on cmpxchg failure */
+		if (local_try_cmpxchg(&bpage->write, &old_index, new_index)) {
 			/* update counters */
 			local_sub(event_length, &cpu_buffer->entries_bytes);
 			return true;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8e64aaa..3e55375 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3119,7 +3119,6 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer,
 	struct ftrace_stack *fstack;
 	struct stack_entry *entry;
 	int stackidx;
-	void *ptr;
 
 	/*
 	 * Add one, for this function and the call to save_stack_trace()
@@ -3157,32 +3156,16 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer,
 		nr_entries = stack_trace_save(fstack->calls, size, skip);
 	}
 
-	size = nr_entries * sizeof(unsigned long);
 	event = __trace_buffer_lock_reserve(buffer, TRACE_STACK,
-				    (sizeof(*entry) - sizeof(entry->caller)) + size,
+				    struct_size(entry, caller, nr_entries),
 				    trace_ctx);
 	if (!event)
 		goto out;
-	ptr = ring_buffer_event_data(event);
-	entry = ptr;
-
-	/*
-	 * For backward compatibility reasons, the entry->caller is an
-	 * array of 8 slots to store the stack. This is also exported
-	 * to user space. The amount allocated on the ring buffer actually
-	 * holds enough for the stack specified by nr_entries. This will
-	 * go into the location of entry->caller. Due to string fortifiers
-	 * checking the size of the destination of memcpy() it triggers
-	 * when it detects that size is greater than 8. To hide this from
-	 * the fortifiers, we use "ptr" and pointer arithmetic to assign caller.
-	 *
-	 * The below is really just:
-	 *   memcpy(&entry->caller, fstack->calls, size);
-	 */
-	ptr += offsetof(typeof(*entry), caller);
-	memcpy(ptr, fstack->calls, size);
+	entry = ring_buffer_event_data(event);
 
 	entry->size = nr_entries;
+	memcpy(&entry->caller, fstack->calls,
+	       flex_array_size(entry, caller, nr_entries));
 
 	if (!call_filter_check_discard(call, entry, buffer, event))
 		__buffer_unlock_commit(buffer, event);
@@ -4206,18 +4189,12 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 	loff_t l = 0;
 	int cpu;
 
-	/*
-	 * copy the tracer to avoid using a global lock all around.
-	 * iter->trace is a copy of current_trace, the pointer to the
-	 * name may be used instead of a strcmp(), as iter->trace->name
-	 * will point to the same string as current_trace->name.
-	 */
 	mutex_lock(&trace_types_lock);
-	if (unlikely(tr->current_trace && iter->trace->name != tr->current_trace->name)) {
+	if (unlikely(tr->current_trace != iter->trace)) {
 		/* Close iter->trace before switching to the new current tracer */
 		if (iter->trace->close)
 			iter->trace->close(iter);
-		*iter->trace = *tr->current_trace;
+		iter->trace = tr->current_trace;
 		/* Reopen the new current tracer */
 		if (iter->trace->open)
 			iter->trace->open(iter);
@@ -4829,6 +4806,25 @@ static const struct seq_operations tracer_seq_ops = {
 	.show		= s_show,
 };
 
+/*
+ * Note, as iter itself can be allocated and freed in different
+ * ways, this function is only used to free its content, and not
+ * the iterator itself. The only requirement to all the allocations
+ * is that it must zero all fields (kzalloc), as freeing works with
+ * ethier allocated content or NULL.
+ */
+static void free_trace_iter_content(struct trace_iterator *iter)
+{
+	/* The fmt is either NULL, allocated or points to static_fmt_buf */
+	if (iter->fmt != static_fmt_buf)
+		kfree(iter->fmt);
+
+	kfree(iter->temp);
+	kfree(iter->buffer_iter);
+	mutex_destroy(&iter->mutex);
+	free_cpumask_var(iter->started);
+}
+
 static struct trace_iterator *
 __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 {
@@ -4870,16 +4866,8 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	iter->fmt = NULL;
 	iter->fmt_size = 0;
 
-	/*
-	 * We make a copy of the current tracer to avoid concurrent
-	 * changes on it while we are reading.
-	 */
 	mutex_lock(&trace_types_lock);
-	iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL);
-	if (!iter->trace)
-		goto fail;
-
-	*iter->trace = *tr->current_trace;
+	iter->trace = tr->current_trace;
 
 	if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
 		goto fail;
@@ -4944,9 +4932,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 
  fail:
 	mutex_unlock(&trace_types_lock);
-	kfree(iter->trace);
-	kfree(iter->temp);
-	kfree(iter->buffer_iter);
+	free_trace_iter_content(iter);
 release:
 	seq_release_private(inode, file);
 	return ERR_PTR(-ENOMEM);
@@ -5025,12 +5011,7 @@ static int tracing_release(struct inode *inode, struct file *file)
 
 	mutex_unlock(&trace_types_lock);
 
-	mutex_destroy(&iter->mutex);
-	free_cpumask_var(iter->started);
-	kfree(iter->fmt);
-	kfree(iter->temp);
-	kfree(iter->trace);
-	kfree(iter->buffer_iter);
+	free_trace_iter_content(iter);
 	seq_release_private(inode, file);
 
 	return 0;
@@ -6318,6 +6299,15 @@ static void set_buffer_entries(struct array_buffer *buf, unsigned long val)
 		per_cpu_ptr(buf->data, cpu)->entries = val;
 }
 
+static void update_buffer_entries(struct array_buffer *buf, int cpu)
+{
+	if (cpu == RING_BUFFER_ALL_CPUS) {
+		set_buffer_entries(buf, ring_buffer_size(buf->buffer, 0));
+	} else {
+		per_cpu_ptr(buf->data, cpu)->entries = ring_buffer_size(buf->buffer, cpu);
+	}
+}
+
 #ifdef CONFIG_TRACER_MAX_TRACE
 /* resize @tr's buffer to the size of @size_tr's entries */
 static int resize_buffer_duplicate_size(struct array_buffer *trace_buf,
@@ -6396,18 +6386,12 @@ static int __tracing_resize_ring_buffer(struct trace_array *tr,
 		return ret;
 	}
 
-	if (cpu == RING_BUFFER_ALL_CPUS)
-		set_buffer_entries(&tr->max_buffer, size);
-	else
-		per_cpu_ptr(tr->max_buffer.data, cpu)->entries = size;
+	update_buffer_entries(&tr->max_buffer, cpu);
 
  out:
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
-	if (cpu == RING_BUFFER_ALL_CPUS)
-		set_buffer_entries(&tr->array_buffer, size);
-	else
-		per_cpu_ptr(tr->array_buffer.data, cpu)->entries = size;
+	update_buffer_entries(&tr->array_buffer, cpu);
 
 	return ret;
 }
@@ -6825,10 +6809,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
 	close_pipe_on_cpu(tr, iter->cpu_file);
 	mutex_unlock(&trace_types_lock);
 
-	free_cpumask_var(iter->started);
-	kfree(iter->fmt);
-	kfree(iter->temp);
-	mutex_destroy(&iter->mutex);
+	free_trace_iter_content(iter);
 	kfree(iter);
 
 	trace_array_put(tr);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 73eaec1..5669dd1 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -77,6 +77,16 @@ enum trace_type {
 #undef __array
 #define __array(type, item, size)	type	item[size];
 
+/*
+ * For backward compatibility, older user space expects to see the
+ * kernel_stack event with a fixed size caller field. But today the fix
+ * size is ignored by the kernel, and the real structure is dynamic.
+ * Expose to user space: "unsigned long caller[8];" but the real structure
+ * will be "unsigned long caller[] __counted_by(size)"
+ */
+#undef __stack_array
+#define __stack_array(type, item, size, field)		type item[] __counted_by(field);
+
 #undef __array_desc
 #define __array_desc(type, container, item, size)
 
@@ -596,7 +606,6 @@ trace_buffer_iter(struct trace_iterator *iter, int cpu)
 int tracer_init(struct tracer *t, struct trace_array *tr);
 int tracing_is_enabled(void);
 void tracing_reset_online_cpus(struct array_buffer *buf);
-void tracing_reset_current(int cpu);
 void tracing_reset_all_online_cpus(void);
 void tracing_reset_all_online_cpus_unlocked(void);
 int tracing_open_generic(struct inode *inode, struct file *filp);
@@ -697,7 +706,6 @@ void trace_filter_add_remove_task(struct trace_pid_list *pid_list,
 void *trace_pid_next(struct trace_pid_list *pid_list, void *v, loff_t *pos);
 void *trace_pid_start(struct trace_pid_list *pid_list, loff_t *pos);
 int trace_pid_show(struct seq_file *m, void *v);
-void trace_free_pid_list(struct trace_pid_list *pid_list);
 int trace_pid_write(struct trace_pid_list *filtered_pids,
 		    struct trace_pid_list **new_pid_list,
 		    const char __user *ubuf, size_t cnt);
@@ -1334,7 +1342,7 @@ struct trace_subsystem_dir {
 	struct list_head		list;
 	struct event_subsystem		*subsystem;
 	struct trace_array		*tr;
-	struct dentry			*entry;
+	struct eventfs_file             *ef;
 	int				ref_count;
 	int				nr_events;
 };
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index 340b2fa..c47422b 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -190,7 +190,7 @@ FTRACE_ENTRY(kernel_stack, stack_entry,
 
 	F_STRUCT(
 		__field(	int,		size	)
-		__array(	unsigned long,	caller,	FTRACE_STACK_ENTRIES	)
+		__stack_array(	unsigned long,	caller,	FTRACE_STACK_ENTRIES, size)
 	),
 
 	F_printk("\t=> %ps\n\t=> %ps\n\t=> %ps\n"
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 578f1f7..ed367d7 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -984,7 +984,7 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
 		return;
 
 	if (!--dir->nr_events) {
-		tracefs_remove(dir->entry);
+		eventfs_remove(dir->ef);
 		list_del(&dir->list);
 		__put_system_dir(dir);
 	}
@@ -1005,7 +1005,7 @@ static void remove_event_file_dir(struct trace_event_file *file)
 
 		tracefs_remove(dir);
 	}
-
+	eventfs_remove(file->ef);
 	list_del(&file->list);
 	remove_subsystem(file->system);
 	free_event_filter(file->filter);
@@ -2291,13 +2291,13 @@ create_new_subsystem(const char *name)
 	return NULL;
 }
 
-static struct dentry *
+static struct eventfs_file *
 event_subsystem_dir(struct trace_array *tr, const char *name,
 		    struct trace_event_file *file, struct dentry *parent)
 {
 	struct event_subsystem *system, *iter;
 	struct trace_subsystem_dir *dir;
-	struct dentry *entry;
+	int res;
 
 	/* First see if we did not already create this dir */
 	list_for_each_entry(dir, &tr->systems, list) {
@@ -2305,7 +2305,7 @@ event_subsystem_dir(struct trace_array *tr, const char *name,
 		if (strcmp(system->name, name) == 0) {
 			dir->nr_events++;
 			file->system = dir;
-			return dir->entry;
+			return dir->ef;
 		}
 	}
 
@@ -2329,8 +2329,8 @@ event_subsystem_dir(struct trace_array *tr, const char *name,
 	} else
 		__get_system(system);
 
-	dir->entry = tracefs_create_dir(name, parent);
-	if (!dir->entry) {
+	dir->ef = eventfs_add_subsystem_dir(name, parent);
+	if (IS_ERR(dir->ef)) {
 		pr_warn("Failed to create system directory %s\n", name);
 		__put_system(system);
 		goto out_free;
@@ -2345,22 +2345,22 @@ event_subsystem_dir(struct trace_array *tr, const char *name,
 	/* the ftrace system is special, do not create enable or filter files */
 	if (strcmp(name, "ftrace") != 0) {
 
-		entry = tracefs_create_file("filter", TRACE_MODE_WRITE,
-					    dir->entry, dir,
+		res = eventfs_add_file("filter", TRACE_MODE_WRITE,
+					    dir->ef, dir,
 					    &ftrace_subsystem_filter_fops);
-		if (!entry) {
+		if (res) {
 			kfree(system->filter);
 			system->filter = NULL;
 			pr_warn("Could not create tracefs '%s/filter' entry\n", name);
 		}
 
-		trace_create_file("enable", TRACE_MODE_WRITE, dir->entry, dir,
+		eventfs_add_file("enable", TRACE_MODE_WRITE, dir->ef, dir,
 				  &ftrace_system_enable_fops);
 	}
 
 	list_add(&dir->list, &tr->systems);
 
-	return dir->entry;
+	return dir->ef;
 
  out_free:
 	kfree(dir);
@@ -2413,36 +2413,37 @@ static int
 event_create_dir(struct dentry *parent, struct trace_event_file *file)
 {
 	struct trace_event_call *call = file->event_call;
+	struct eventfs_file *ef_subsystem = NULL;
 	struct trace_array *tr = file->tr;
-	struct dentry *d_events;
 	const char *name;
 	int ret;
 
 	/*
 	 * If the trace point header did not define TRACE_SYSTEM
-	 * then the system would be called "TRACE_SYSTEM".
+	 * then the system would be called "TRACE_SYSTEM". This should
+	 * never happen.
 	 */
-	if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
-		d_events = event_subsystem_dir(tr, call->class->system, file, parent);
-		if (!d_events)
-			return -ENOMEM;
-	} else
-		d_events = parent;
+	if (WARN_ON_ONCE(strcmp(call->class->system, TRACE_SYSTEM) == 0))
+		return -ENODEV;
+
+	ef_subsystem = event_subsystem_dir(tr, call->class->system, file, parent);
+	if (!ef_subsystem)
+		return -ENOMEM;
 
 	name = trace_event_name(call);
-	file->dir = tracefs_create_dir(name, d_events);
-	if (!file->dir) {
+	file->ef = eventfs_add_dir(name, ef_subsystem);
+	if (IS_ERR(file->ef)) {
 		pr_warn("Could not create tracefs '%s' directory\n", name);
 		return -1;
 	}
 
 	if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
-		trace_create_file("enable", TRACE_MODE_WRITE, file->dir, file,
+		eventfs_add_file("enable", TRACE_MODE_WRITE, file->ef, file,
 				  &ftrace_enable_fops);
 
 #ifdef CONFIG_PERF_EVENTS
 	if (call->event.type && call->class->reg)
-		trace_create_file("id", TRACE_MODE_READ, file->dir,
+		eventfs_add_file("id", TRACE_MODE_READ, file->ef,
 				  (void *)(long)call->event.type,
 				  &ftrace_event_id_fops);
 #endif
@@ -2458,27 +2459,27 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
 	 * triggers or filters.
 	 */
 	if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
-		trace_create_file("filter", TRACE_MODE_WRITE, file->dir,
+		eventfs_add_file("filter", TRACE_MODE_WRITE, file->ef,
 				  file, &ftrace_event_filter_fops);
 
-		trace_create_file("trigger", TRACE_MODE_WRITE, file->dir,
+		eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef,
 				  file, &event_trigger_fops);
 	}
 
 #ifdef CONFIG_HIST_TRIGGERS
-	trace_create_file("hist", TRACE_MODE_READ, file->dir, file,
+	eventfs_add_file("hist", TRACE_MODE_READ, file->ef, file,
 			  &event_hist_fops);
 #endif
 #ifdef CONFIG_HIST_TRIGGERS_DEBUG
-	trace_create_file("hist_debug", TRACE_MODE_READ, file->dir, file,
+	eventfs_add_file("hist_debug", TRACE_MODE_READ, file->ef, file,
 			  &event_hist_debug_fops);
 #endif
-	trace_create_file("format", TRACE_MODE_READ, file->dir, call,
+	eventfs_add_file("format", TRACE_MODE_READ, file->ef, call,
 			  &ftrace_event_format_fops);
 
 #ifdef CONFIG_TRACE_EVENT_INJECT
 	if (call->event.type && call->class->reg)
-		trace_create_file("inject", 0200, file->dir, file,
+		eventfs_add_file("inject", 0200, file->ef, file,
 				  &event_inject_fops);
 #endif
 
@@ -3631,21 +3632,22 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
 {
 	struct dentry *d_events;
 	struct dentry *entry;
+	int error = 0;
 
 	entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
 				  tr, &ftrace_set_event_fops);
 	if (!entry)
 		return -ENOMEM;
 
-	d_events = tracefs_create_dir("events", parent);
-	if (!d_events) {
+	d_events = eventfs_create_events_dir("events", parent);
+	if (IS_ERR(d_events)) {
 		pr_warn("Could not create tracefs 'events' directory\n");
 		return -ENOMEM;
 	}
 
-	entry = trace_create_file("enable", TRACE_MODE_WRITE, d_events,
+	error = eventfs_add_events_file("enable", TRACE_MODE_WRITE, d_events,
 				  tr, &ftrace_tr_enable_fops);
-	if (!entry)
+	if (error)
 		return -ENOMEM;
 
 	/* There are not as crucial, just warn if they are not created */
@@ -3658,11 +3660,11 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
 			  &ftrace_set_event_notrace_pid_fops);
 
 	/* ring buffer internal formats */
-	trace_create_file("header_page", TRACE_MODE_READ, d_events,
+	eventfs_add_events_file("header_page", TRACE_MODE_READ, d_events,
 				  ring_buffer_print_page_header,
 				  &ftrace_show_header_fops);
 
-	trace_create_file("header_event", TRACE_MODE_READ, d_events,
+	eventfs_add_events_file("header_event", TRACE_MODE_READ, d_events,
 				  ring_buffer_print_entry_header,
 				  &ftrace_show_header_fops);
 
@@ -3750,7 +3752,7 @@ int event_trace_del_tracer(struct trace_array *tr)
 
 	down_write(&trace_event_sem);
 	__trace_remove_event_dirs(tr);
-	tracefs_remove(tr->event_dir);
+	eventfs_remove_events_dir(tr->event_dir);
 	up_write(&trace_event_sem);
 
 	tr->event_dir = NULL;
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 1dad642..3a52921 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -46,15 +46,19 @@ static const char * ops[] = { OPS };
 enum filter_pred_fn {
 	FILTER_PRED_FN_NOP,
 	FILTER_PRED_FN_64,
+	FILTER_PRED_FN_64_CPUMASK,
 	FILTER_PRED_FN_S64,
 	FILTER_PRED_FN_U64,
 	FILTER_PRED_FN_32,
+	FILTER_PRED_FN_32_CPUMASK,
 	FILTER_PRED_FN_S32,
 	FILTER_PRED_FN_U32,
 	FILTER_PRED_FN_16,
+	FILTER_PRED_FN_16_CPUMASK,
 	FILTER_PRED_FN_S16,
 	FILTER_PRED_FN_U16,
 	FILTER_PRED_FN_8,
+	FILTER_PRED_FN_8_CPUMASK,
 	FILTER_PRED_FN_S8,
 	FILTER_PRED_FN_U8,
 	FILTER_PRED_FN_COMM,
@@ -64,21 +68,25 @@ enum filter_pred_fn {
 	FILTER_PRED_FN_PCHAR_USER,
 	FILTER_PRED_FN_PCHAR,
 	FILTER_PRED_FN_CPU,
+	FILTER_PRED_FN_CPU_CPUMASK,
+	FILTER_PRED_FN_CPUMASK,
+	FILTER_PRED_FN_CPUMASK_CPU,
 	FILTER_PRED_FN_FUNCTION,
 	FILTER_PRED_FN_,
 	FILTER_PRED_TEST_VISITED,
 };
 
 struct filter_pred {
-	enum filter_pred_fn 	fn_num;
-	u64 			val;
-	u64 			val2;
-	struct regex		regex;
+	struct regex		*regex;
+	struct cpumask          *mask;
 	unsigned short		*ops;
 	struct ftrace_event_field *field;
-	int 			offset;
+	u64			val;
+	u64			val2;
+	enum filter_pred_fn	fn_num;
+	int			offset;
 	int			not;
-	int 			op;
+	int			op;
 };
 
 /*
@@ -94,6 +102,8 @@ struct filter_pred {
 	C(TOO_MANY_OPEN,	"Too many '('"),			\
 	C(TOO_MANY_CLOSE,	"Too few '('"),				\
 	C(MISSING_QUOTE,	"Missing matching quote"),		\
+	C(MISSING_BRACE_OPEN,   "Missing '{'"),				\
+	C(MISSING_BRACE_CLOSE,  "Missing '}'"),				\
 	C(OPERAND_TOO_LONG,	"Operand too long"),			\
 	C(EXPECT_STRING,	"Expecting string field"),		\
 	C(EXPECT_DIGIT,		"Expecting numeric field"),		\
@@ -103,6 +113,7 @@ struct filter_pred {
 	C(BAD_SUBSYS_FILTER,	"Couldn't find or set field in one of a subsystem's events"), \
 	C(TOO_MANY_PREDS,	"Too many terms in predicate expression"), \
 	C(INVALID_FILTER,	"Meaningless filter expression"),	\
+	C(INVALID_CPULIST,	"Invalid cpulist"),	\
 	C(IP_FIELD_ONLY,	"Only 'ip' field is supported for function trace"), \
 	C(INVALID_VALUE,	"Invalid value (did you forget quotes)?"), \
 	C(NO_FUNCTION,		"Function not found"),			\
@@ -186,6 +197,15 @@ enum {
 	PROCESS_OR	= 4,
 };
 
+static void free_predicate(struct filter_pred *pred)
+{
+	if (pred) {
+		kfree(pred->regex);
+		kfree(pred->mask);
+		kfree(pred);
+	}
+}
+
 /*
  * Without going into a formal proof, this explains the method that is used in
  * parsing the logical expressions.
@@ -623,12 +643,64 @@ out_free:
 	kfree(inverts);
 	if (prog_stack) {
 		for (i = 0; prog_stack[i].pred; i++)
-			kfree(prog_stack[i].pred);
+			free_predicate(prog_stack[i].pred);
 		kfree(prog_stack);
 	}
 	return ERR_PTR(ret);
 }
 
+static inline int
+do_filter_cpumask(int op, const struct cpumask *mask, const struct cpumask *cmp)
+{
+	switch (op) {
+	case OP_EQ:
+		return cpumask_equal(mask, cmp);
+	case OP_NE:
+		return !cpumask_equal(mask, cmp);
+	case OP_BAND:
+		return cpumask_intersects(mask, cmp);
+	default:
+		return 0;
+	}
+}
+
+/* Optimisation of do_filter_cpumask() for scalar fields */
+static inline int
+do_filter_scalar_cpumask(int op, unsigned int cpu, const struct cpumask *mask)
+{
+	/*
+	 * Per the weight-of-one cpumask optimisations, the mask passed in this
+	 * function has a weight >= 2, so it is never equal to a single scalar.
+	 */
+	switch (op) {
+	case OP_EQ:
+		return false;
+	case OP_NE:
+		return true;
+	case OP_BAND:
+		return cpumask_test_cpu(cpu, mask);
+	default:
+		return 0;
+	}
+}
+
+static inline int
+do_filter_cpumask_scalar(int op, const struct cpumask *mask, unsigned int cpu)
+{
+	switch (op) {
+	case OP_EQ:
+		return cpumask_test_cpu(cpu, mask) &&
+			cpumask_nth(1, mask) >= nr_cpu_ids;
+	case OP_NE:
+		return !cpumask_test_cpu(cpu, mask) ||
+			cpumask_nth(1, mask) < nr_cpu_ids;
+	case OP_BAND:
+		return cpumask_test_cpu(cpu, mask);
+	default:
+		return 0;
+	}
+}
+
 enum pred_cmp_types {
 	PRED_CMP_TYPE_NOP,
 	PRED_CMP_TYPE_LT,
@@ -672,6 +744,18 @@ static int filter_pred_##type(struct filter_pred *pred, void *event)	\
 	}								\
 }
 
+#define DEFINE_CPUMASK_COMPARISON_PRED(size)					\
+static int filter_pred_##size##_cpumask(struct filter_pred *pred, void *event)	\
+{										\
+	u##size *addr = (u##size *)(event + pred->offset);			\
+	unsigned int cpu = *addr;						\
+										\
+	if (cpu >= nr_cpu_ids)							\
+		return 0;							\
+										\
+	return do_filter_scalar_cpumask(pred->op, cpu, pred->mask);		\
+}
+
 #define DEFINE_EQUALITY_PRED(size)					\
 static int filter_pred_##size(struct filter_pred *pred, void *event)	\
 {									\
@@ -693,6 +777,11 @@ DEFINE_COMPARISON_PRED(u16);
 DEFINE_COMPARISON_PRED(s8);
 DEFINE_COMPARISON_PRED(u8);
 
+DEFINE_CPUMASK_COMPARISON_PRED(64);
+DEFINE_CPUMASK_COMPARISON_PRED(32);
+DEFINE_CPUMASK_COMPARISON_PRED(16);
+DEFINE_CPUMASK_COMPARISON_PRED(8);
+
 DEFINE_EQUALITY_PRED(64);
 DEFINE_EQUALITY_PRED(32);
 DEFINE_EQUALITY_PRED(16);
@@ -750,7 +839,7 @@ static int filter_pred_string(struct filter_pred *pred, void *event)
 	char *addr = (char *)(event + pred->offset);
 	int cmp, match;
 
-	cmp = pred->regex.match(addr, &pred->regex, pred->regex.field_len);
+	cmp = pred->regex->match(addr, pred->regex, pred->regex->field_len);
 
 	match = cmp ^ pred->not;
 
@@ -763,7 +852,7 @@ static __always_inline int filter_pchar(struct filter_pred *pred, char *str)
 	int len;
 
 	len = strlen(str) + 1;	/* including tailing '\0' */
-	cmp = pred->regex.match(str, &pred->regex, len);
+	cmp = pred->regex->match(str, pred->regex, len);
 
 	match = cmp ^ pred->not;
 
@@ -813,7 +902,7 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event)
 	char *addr = (char *)(event + str_loc);
 	int cmp, match;
 
-	cmp = pred->regex.match(addr, &pred->regex, str_len);
+	cmp = pred->regex->match(addr, pred->regex, str_len);
 
 	match = cmp ^ pred->not;
 
@@ -836,7 +925,7 @@ static int filter_pred_strrelloc(struct filter_pred *pred, void *event)
 	char *addr = (char *)(&item[1]) + str_loc;
 	int cmp, match;
 
-	cmp = pred->regex.match(addr, &pred->regex, str_len);
+	cmp = pred->regex->match(addr, pred->regex, str_len);
 
 	match = cmp ^ pred->not;
 
@@ -869,12 +958,42 @@ static int filter_pred_cpu(struct filter_pred *pred, void *event)
 	}
 }
 
+/* Filter predicate for current CPU vs user-provided cpumask */
+static int filter_pred_cpu_cpumask(struct filter_pred *pred, void *event)
+{
+	int cpu = raw_smp_processor_id();
+
+	return do_filter_scalar_cpumask(pred->op, cpu, pred->mask);
+}
+
+/* Filter predicate for cpumask field vs user-provided cpumask */
+static int filter_pred_cpumask(struct filter_pred *pred, void *event)
+{
+	u32 item = *(u32 *)(event + pred->offset);
+	int loc = item & 0xffff;
+	const struct cpumask *mask = (event + loc);
+	const struct cpumask *cmp = pred->mask;
+
+	return do_filter_cpumask(pred->op, mask, cmp);
+}
+
+/* Filter predicate for cpumask field vs user-provided scalar  */
+static int filter_pred_cpumask_cpu(struct filter_pred *pred, void *event)
+{
+	u32 item = *(u32 *)(event + pred->offset);
+	int loc = item & 0xffff;
+	const struct cpumask *mask = (event + loc);
+	unsigned int cpu = pred->val;
+
+	return do_filter_cpumask_scalar(pred->op, mask, cpu);
+}
+
 /* Filter predicate for COMM. */
 static int filter_pred_comm(struct filter_pred *pred, void *event)
 {
 	int cmp;
 
-	cmp = pred->regex.match(current->comm, &pred->regex,
+	cmp = pred->regex->match(current->comm, pred->regex,
 				TASK_COMM_LEN);
 	return cmp ^ pred->not;
 }
@@ -1004,7 +1123,7 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
 
 static void filter_build_regex(struct filter_pred *pred)
 {
-	struct regex *r = &pred->regex;
+	struct regex *r = pred->regex;
 	char *search;
 	enum regex_type type = MATCH_FULL;
 
@@ -1169,7 +1288,7 @@ static void free_prog(struct event_filter *filter)
 		return;
 
 	for (i = 0; prog[i].pred; i++)
-		kfree(prog[i].pred);
+		free_predicate(prog[i].pred);
 	kfree(prog);
 }
 
@@ -1236,8 +1355,12 @@ static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir,
 
 int filter_assign_type(const char *type)
 {
-	if (strstr(type, "__data_loc") && strstr(type, "char"))
-		return FILTER_DYN_STRING;
+	if (strstr(type, "__data_loc")) {
+		if (strstr(type, "char"))
+			return FILTER_DYN_STRING;
+		if (strstr(type, "cpumask_t"))
+			return FILTER_CPUMASK;
+		}
 
 	if (strstr(type, "__rel_loc") && strstr(type, "char"))
 		return FILTER_RDYN_STRING;
@@ -1313,24 +1436,32 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event)
 	switch (pred->fn_num) {
 	case FILTER_PRED_FN_64:
 		return filter_pred_64(pred, event);
+	case FILTER_PRED_FN_64_CPUMASK:
+		return filter_pred_64_cpumask(pred, event);
 	case FILTER_PRED_FN_S64:
 		return filter_pred_s64(pred, event);
 	case FILTER_PRED_FN_U64:
 		return filter_pred_u64(pred, event);
 	case FILTER_PRED_FN_32:
 		return filter_pred_32(pred, event);
+	case FILTER_PRED_FN_32_CPUMASK:
+		return filter_pred_32_cpumask(pred, event);
 	case FILTER_PRED_FN_S32:
 		return filter_pred_s32(pred, event);
 	case FILTER_PRED_FN_U32:
 		return filter_pred_u32(pred, event);
 	case FILTER_PRED_FN_16:
 		return filter_pred_16(pred, event);
+	case FILTER_PRED_FN_16_CPUMASK:
+		return filter_pred_16_cpumask(pred, event);
 	case FILTER_PRED_FN_S16:
 		return filter_pred_s16(pred, event);
 	case FILTER_PRED_FN_U16:
 		return filter_pred_u16(pred, event);
 	case FILTER_PRED_FN_8:
 		return filter_pred_8(pred, event);
+	case FILTER_PRED_FN_8_CPUMASK:
+		return filter_pred_8_cpumask(pred, event);
 	case FILTER_PRED_FN_S8:
 		return filter_pred_s8(pred, event);
 	case FILTER_PRED_FN_U8:
@@ -1349,6 +1480,12 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event)
 		return filter_pred_pchar(pred, event);
 	case FILTER_PRED_FN_CPU:
 		return filter_pred_cpu(pred, event);
+	case FILTER_PRED_FN_CPU_CPUMASK:
+		return filter_pred_cpu_cpumask(pred, event);
+	case FILTER_PRED_FN_CPUMASK:
+		return filter_pred_cpumask(pred, event);
+	case FILTER_PRED_FN_CPUMASK_CPU:
+		return filter_pred_cpumask_cpu(pred, event);
 	case FILTER_PRED_FN_FUNCTION:
 		return filter_pred_function(pred, event);
 	case FILTER_PRED_TEST_VISITED:
@@ -1553,9 +1690,117 @@ static int parse_pred(const char *str, void *data,
 			goto err_free;
 		}
 
-		pred->regex.len = len;
-		strncpy(pred->regex.pattern, str + s, len);
-		pred->regex.pattern[len] = 0;
+		pred->regex = kzalloc(sizeof(*pred->regex), GFP_KERNEL);
+		if (!pred->regex)
+			goto err_mem;
+		pred->regex->len = len;
+		strncpy(pred->regex->pattern, str + s, len);
+		pred->regex->pattern[len] = 0;
+
+	} else if (!strncmp(str + i, "CPUS", 4)) {
+		unsigned int maskstart;
+		bool single;
+		char *tmp;
+
+		switch (field->filter_type) {
+		case FILTER_CPUMASK:
+		case FILTER_CPU:
+		case FILTER_OTHER:
+			break;
+		default:
+			parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
+			goto err_free;
+		}
+
+		switch (op) {
+		case OP_EQ:
+		case OP_NE:
+		case OP_BAND:
+			break;
+		default:
+			parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
+			goto err_free;
+		}
+
+		/* Skip CPUS */
+		i += 4;
+		if (str[i++] != '{') {
+			parse_error(pe, FILT_ERR_MISSING_BRACE_OPEN, pos + i);
+			goto err_free;
+		}
+		maskstart = i;
+
+		/* Walk the cpulist until closing } */
+		for (; str[i] && str[i] != '}'; i++);
+		if (str[i] != '}') {
+			parse_error(pe, FILT_ERR_MISSING_BRACE_CLOSE, pos + i);
+			goto err_free;
+		}
+
+		if (maskstart == i) {
+			parse_error(pe, FILT_ERR_INVALID_CPULIST, pos + i);
+			goto err_free;
+		}
+
+		/* Copy the cpulist between { and } */
+		tmp = kmalloc((i - maskstart) + 1, GFP_KERNEL);
+		strscpy(tmp, str + maskstart, (i - maskstart) + 1);
+
+		pred->mask = kzalloc(cpumask_size(), GFP_KERNEL);
+		if (!pred->mask)
+			goto err_mem;
+
+		/* Now parse it */
+		if (cpulist_parse(tmp, pred->mask)) {
+			parse_error(pe, FILT_ERR_INVALID_CPULIST, pos + i);
+			goto err_free;
+		}
+
+		/* Move along */
+		i++;
+
+		/*
+		 * Optimisation: if the user-provided mask has a weight of one
+		 * then we can treat it as a scalar input.
+		 */
+		single = cpumask_weight(pred->mask) == 1;
+		if (single) {
+			pred->val = cpumask_first(pred->mask);
+			kfree(pred->mask);
+		}
+
+		if (field->filter_type == FILTER_CPUMASK) {
+			pred->fn_num = single ?
+				FILTER_PRED_FN_CPUMASK_CPU :
+				FILTER_PRED_FN_CPUMASK;
+		} else if (field->filter_type == FILTER_CPU) {
+			if (single) {
+				pred->op = pred->op == OP_BAND ? OP_EQ : pred->op;
+				pred->fn_num = FILTER_PRED_FN_CPU;
+			} else {
+				pred->fn_num = FILTER_PRED_FN_CPU_CPUMASK;
+			}
+		} else if (single) {
+			pred->op = pred->op == OP_BAND ? OP_EQ : pred->op;
+			pred->fn_num = select_comparison_fn(pred->op, field->size, false);
+			if (pred->op == OP_NE)
+				pred->not = 1;
+		} else {
+			switch (field->size) {
+			case 8:
+				pred->fn_num = FILTER_PRED_FN_64_CPUMASK;
+				break;
+			case 4:
+				pred->fn_num = FILTER_PRED_FN_32_CPUMASK;
+				break;
+			case 2:
+				pred->fn_num = FILTER_PRED_FN_16_CPUMASK;
+				break;
+			case 1:
+				pred->fn_num = FILTER_PRED_FN_8_CPUMASK;
+				break;
+			}
+		}
 
 	/* This is either a string, or an integer */
 	} else if (str[i] == '\'' || str[i] == '"') {
@@ -1597,9 +1842,12 @@ static int parse_pred(const char *str, void *data,
 			goto err_free;
 		}
 
-		pred->regex.len = len;
-		strncpy(pred->regex.pattern, str + s, len);
-		pred->regex.pattern[len] = 0;
+		pred->regex = kzalloc(sizeof(*pred->regex), GFP_KERNEL);
+		if (!pred->regex)
+			goto err_mem;
+		pred->regex->len = len;
+		strncpy(pred->regex->pattern, str + s, len);
+		pred->regex->pattern[len] = 0;
 
 		filter_build_regex(pred);
 
@@ -1608,7 +1856,7 @@ static int parse_pred(const char *str, void *data,
 
 		} else if (field->filter_type == FILTER_STATIC_STRING) {
 			pred->fn_num = FILTER_PRED_FN_STRING;
-			pred->regex.field_len = field->size;
+			pred->regex->field_len = field->size;
 
 		} else if (field->filter_type == FILTER_DYN_STRING) {
 			pred->fn_num = FILTER_PRED_FN_STRLOC;
@@ -1691,10 +1939,10 @@ static int parse_pred(const char *str, void *data,
 	return i;
 
 err_free:
-	kfree(pred);
+	free_predicate(pred);
 	return -EINVAL;
 err_mem:
-	kfree(pred);
+	free_predicate(pred);
 	return -ENOMEM;
 }
 
@@ -2287,8 +2535,8 @@ static int ftrace_function_set_filter_pred(struct filter_pred *pred,
 		return ret;
 
 	return __ftrace_function_set_filter(pred->op == OP_EQ,
-					    pred->regex.pattern,
-					    pred->regex.len,
+					    pred->regex->pattern,
+					    pred->regex->len,
 					    data);
 }
 
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 33cb6af..6f04665 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1328,14 +1328,14 @@ static int user_field_set_string(struct ftrace_event_field *field,
 
 static int user_event_set_print_fmt(struct user_event *user, char *buf, int len)
 {
-	struct ftrace_event_field *field, *next;
+	struct ftrace_event_field *field;
 	struct list_head *head = &user->fields;
 	int pos = 0, depth = 0;
 	const char *str_func;
 
 	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
 
-	list_for_each_entry_safe_reverse(field, next, head, link) {
+	list_for_each_entry_reverse(field, head, link) {
 		if (depth != 0)
 			pos += snprintf(buf + pos, LEN_OR_ZERO, " ");
 
@@ -1347,7 +1347,7 @@ static int user_event_set_print_fmt(struct user_event *user, char *buf, int len)
 
 	pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
 
-	list_for_each_entry_safe_reverse(field, next, head, link) {
+	list_for_each_entry_reverse(field, head, link) {
 		if (user_field_is_dyn_string(field->type, &str_func))
 			pos += snprintf(buf + pos, LEN_OR_ZERO,
 					", %s(%s)", str_func, field->name);
@@ -1732,7 +1732,7 @@ static int user_event_create(const char *raw_command)
 static int user_event_show(struct seq_file *m, struct dyn_event *ev)
 {
 	struct user_event *user = container_of(ev, struct user_event, devent);
-	struct ftrace_event_field *field, *next;
+	struct ftrace_event_field *field;
 	struct list_head *head;
 	int depth = 0;
 
@@ -1740,7 +1740,7 @@ static int user_event_show(struct seq_file *m, struct dyn_event *ev)
 
 	head = trace_get_fields(&user->call);
 
-	list_for_each_entry_safe_reverse(field, next, head, link) {
+	list_for_each_entry_reverse(field, head, link) {
 		if (depth == 0)
 			seq_puts(m, " ");
 		else
@@ -1816,13 +1816,14 @@ out:
 static bool user_fields_match(struct user_event *user, int argc,
 			      const char **argv)
 {
-	struct ftrace_event_field *field, *next;
+	struct ftrace_event_field *field;
 	struct list_head *head = &user->fields;
 	int i = 0;
 
-	list_for_each_entry_safe_reverse(field, next, head, link)
+	list_for_each_entry_reverse(field, head, link) {
 		if (!user_field_match(field, argc, argv, &i))
 			return false;
+	}
 
 	if (i != argc)
 		return false;
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 58f3946..1698fc2 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -51,6 +51,9 @@ static int ftrace_event_register(struct trace_event_call *call,
 #undef __array
 #define __array(type, item, size)			type item[size];
 
+#undef __stack_array
+#define __stack_array(type, item, size, field)		__array(type, item, size)
+
 #undef __array_desc
 #define __array_desc(type, container, item, size)	type item[size];
 
@@ -114,6 +117,9 @@ static void __always_unused ____ftrace_check_##name(void)		\
 	is_signed_type(_type), .filter_type = FILTER_OTHER,			\
 	.len = _len },
 
+#undef __stack_array
+#define __stack_array(_type, _item, _len, _field) __array(_type, _item, _len)
+
 #undef __array_desc
 #define __array_desc(_type, _container, _item, _len) __array(_type, _item, _len)
 
@@ -149,6 +155,9 @@ static struct trace_event_fields ftrace_event_fields_##name[] = {	\
 #undef __array
 #define __array(type, item, len)
 
+#undef __stack_array
+#define __stack_array(type, item, len, field)
+
 #undef __array_desc
 #define __array_desc(type, container, item, len)
 
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc
index 285b477..ff7499e 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc
@@ -34,14 +34,19 @@ mips*)
 esac
 
 : "Test get argument (1)"
-echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char" > kprobe_events
+if grep -q eventfs_add_dir available_filter_functions; then
+  DIR_NAME="eventfs_add_dir"
+else
+  DIR_NAME="tracefs_create_dir"
+fi
+echo "p:testprobe ${DIR_NAME} arg1=+0(${ARG1}):char" > kprobe_events
 echo 1 > events/kprobes/testprobe/enable
 echo "p:test $FUNCTION_FORK" >> kprobe_events
 grep -qe "testprobe.* arg1='t'" trace
 
 echo 0 > events/kprobes/testprobe/enable
 : "Test get argument (2)"
-echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):char arg2=+0(${ARG1}):char[4]" > kprobe_events
+echo "p:testprobe ${DIR_NAME} arg1=+0(${ARG1}):char arg2=+0(${ARG1}):char[4]" > kprobe_events
 echo 1 > events/kprobes/testprobe/enable
 echo "p:test $FUNCTION_FORK" >> kprobe_events
 grep -qe "testprobe.* arg1='t' arg2={'t','e','s','t'}" trace
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc
index a4f8e7c..a202b2e 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc
@@ -37,14 +37,19 @@ loongarch*)
 esac
 
 : "Test get argument (1)"
-echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):string" > kprobe_events
+if grep -q eventfs_add_dir available_filter_functions; then
+  DIR_NAME="eventfs_add_dir"
+else
+  DIR_NAME="tracefs_create_dir"
+fi
+echo "p:testprobe ${DIR_NAME} arg1=+0(${ARG1}):string" > kprobe_events
 echo 1 > events/kprobes/testprobe/enable
 echo "p:test $FUNCTION_FORK" >> kprobe_events
 grep -qe "testprobe.* arg1=\"test\"" trace
 
 echo 0 > events/kprobes/testprobe/enable
 : "Test get argument (2)"
-echo "p:testprobe tracefs_create_dir arg1=+0(${ARG1}):string arg2=+0(${ARG1}):string" > kprobe_events
+echo "p:testprobe ${DIR_NAME} arg1=+0(${ARG1}):string arg2=+0(${ARG1}):string" > kprobe_events
 echo 1 > events/kprobes/testprobe/enable
 echo "p:test $FUNCTION_FORK" >> kprobe_events
 grep -qe "testprobe.* arg1=\"test\" arg2=\"test\"" trace
