Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
new file mode 100644
index 0000000..89779eb
--- /dev/null
+++ b/kernel/trace/trace_dynevent.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic dynamic event control interface
+ *
+ * Copyright (C) 2018 Masami Hiramatsu <mhiramat@kernel.org>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include <linux/tracefs.h>
+
+#include "trace.h"
+#include "trace_dynevent.h"
+
+static DEFINE_MUTEX(dyn_event_ops_mutex);
+static LIST_HEAD(dyn_event_ops_list);
+
+int dyn_event_register(struct dyn_event_operations *ops)
+{
+ if (!ops || !ops->create || !ops->show || !ops->is_busy ||
+ !ops->free || !ops->match)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&ops->list);
+ mutex_lock(&dyn_event_ops_mutex);
+ list_add_tail(&ops->list, &dyn_event_ops_list);
+ mutex_unlock(&dyn_event_ops_mutex);
+ return 0;
+}
+
+int dyn_event_release(int argc, char **argv, struct dyn_event_operations *type)
+{
+ struct dyn_event *pos, *n;
+ char *system = NULL, *event, *p;
+ int ret = -ENOENT;
+
+ if (argv[0][0] == '-') {
+ if (argv[0][1] != ':')
+ return -EINVAL;
+ event = &argv[0][2];
+ } else {
+ event = strchr(argv[0], ':');
+ if (!event)
+ return -EINVAL;
+ event++;
+ }
+ argc--; argv++;
+
+ p = strchr(event, '/');
+ if (p) {
+ system = event;
+ event = p + 1;
+ *p = '\0';
+ }
+ if (event[0] == '\0')
+ return -EINVAL;
+
+ mutex_lock(&event_mutex);
+ for_each_dyn_event_safe(pos, n) {
+ if (type && type != pos->ops)
+ continue;
+ if (!pos->ops->match(system, event,
+ argc, (const char **)argv, pos))
+ continue;
+
+ ret = pos->ops->free(pos);
+ if (ret)
+ break;
+ }
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+
+static int create_dyn_event(int argc, char **argv)
+{
+ struct dyn_event_operations *ops;
+ int ret = -ENODEV;
+
+ if (argv[0][0] == '-' || argv[0][0] == '!')
+ return dyn_event_release(argc, argv, NULL);
+
+ mutex_lock(&dyn_event_ops_mutex);
+ list_for_each_entry(ops, &dyn_event_ops_list, list) {
+ ret = ops->create(argc, (const char **)argv);
+ if (!ret || ret != -ECANCELED)
+ break;
+ }
+ mutex_unlock(&dyn_event_ops_mutex);
+ if (ret == -ECANCELED)
+ ret = -EINVAL;
+
+ return ret;
+}
+
+/* Protected by event_mutex */
+LIST_HEAD(dyn_event_list);
+
+void *dyn_event_seq_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&event_mutex);
+ return seq_list_start(&dyn_event_list, *pos);
+}
+
+void *dyn_event_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ return seq_list_next(v, &dyn_event_list, pos);
+}
+
+void dyn_event_seq_stop(struct seq_file *m, void *v)
+{
+ mutex_unlock(&event_mutex);
+}
+
+static int dyn_event_seq_show(struct seq_file *m, void *v)
+{
+ struct dyn_event *ev = v;
+
+ if (ev && ev->ops)
+ return ev->ops->show(m, ev);
+
+ return 0;
+}
+
+static const struct seq_operations dyn_event_seq_op = {
+ .start = dyn_event_seq_start,
+ .next = dyn_event_seq_next,
+ .stop = dyn_event_seq_stop,
+ .show = dyn_event_seq_show
+};
+
+/*
+ * dyn_events_release_all - Release all specific events
+ * @type: the dyn_event_operations * which filters releasing events
+ *
+ * This releases all events which ->ops matches @type. If @type is NULL,
+ * all events are released.
+ * Return -EBUSY if any of them are in use, and return other errors when
+ * it failed to free the given event. Except for -EBUSY, event releasing
+ * process will be aborted at that point and there may be some other
+ * releasable events on the list.
+ */
+int dyn_events_release_all(struct dyn_event_operations *type)
+{
+ struct dyn_event *ev, *tmp;
+ int ret = 0;
+
+ mutex_lock(&event_mutex);
+ for_each_dyn_event(ev) {
+ if (type && ev->ops != type)
+ continue;
+ if (ev->ops->is_busy(ev)) {
+ ret = -EBUSY;
+ goto out;
+ }
+ }
+ for_each_dyn_event_safe(ev, tmp) {
+ if (type && ev->ops != type)
+ continue;
+ ret = ev->ops->free(ev);
+ if (ret)
+ break;
+ }
+out:
+ mutex_unlock(&event_mutex);
+
+ return ret;
+}
+
+static int dyn_event_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = tracing_check_open_get_tr(NULL);
+ if (ret)
+ return ret;
+
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+ ret = dyn_events_release_all(NULL);
+ if (ret < 0)
+ return ret;
+ }
+
+ return seq_open(file, &dyn_event_seq_op);
+}
+
+static ssize_t dyn_event_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ return trace_parse_run_command(file, buffer, count, ppos,
+ create_dyn_event);
+}
+
+static const struct file_operations dynamic_events_ops = {
+ .owner = THIS_MODULE,
+ .open = dyn_event_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+ .write = dyn_event_write,
+};
+
+/* Make a tracefs interface for controlling dynamic events */
+static __init int init_dynamic_event(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+
+ d_tracer = tracing_init_dentry();
+ if (IS_ERR(d_tracer))
+ return 0;
+
+ entry = tracefs_create_file("dynamic_events", 0644, d_tracer,
+ NULL, &dynamic_events_ops);
+
+ /* Event list interface */
+ if (!entry)
+ pr_warn("Could not create tracefs 'dynamic_events' entry\n");
+
+ return 0;
+}
+fs_initcall(init_dynamic_event);