v4.19.13 snapshot.
diff --git a/tools/lib/traceevent/event-plugin.c b/tools/lib/traceevent/event-plugin.c
new file mode 100644
index 0000000..f17e250
--- /dev/null
+++ b/tools/lib/traceevent/event-plugin.c
@@ -0,0 +1,444 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <dirent.h>
+#include "event-parse.h"
+#include "event-utils.h"
+
+#define LOCAL_PLUGIN_DIR ".traceevent/plugins"
+
+static struct registered_plugin_options {
+ struct registered_plugin_options *next;
+ struct tep_plugin_option *options;
+} *registered_options;
+
+static struct trace_plugin_options {
+ struct trace_plugin_options *next;
+ char *plugin;
+ char *option;
+ char *value;
+} *trace_plugin_options;
+
+struct plugin_list {
+ struct plugin_list *next;
+ char *name;
+ void *handle;
+};
+
+static void lower_case(char *str)
+{
+ if (!str)
+ return;
+ for (; *str; str++)
+ *str = tolower(*str);
+}
+
+static int update_option_value(struct tep_plugin_option *op, const char *val)
+{
+ char *op_val;
+
+ if (!val) {
+ /* toggle, only if option is boolean */
+ if (op->value)
+ /* Warn? */
+ return 0;
+ op->set ^= 1;
+ return 0;
+ }
+
+ /*
+ * If the option has a value then it takes a string
+ * otherwise the option is a boolean.
+ */
+ if (op->value) {
+ op->value = val;
+ return 0;
+ }
+
+ /* Option is boolean, must be either "1", "0", "true" or "false" */
+
+ op_val = strdup(val);
+ if (!op_val)
+ return -1;
+ lower_case(op_val);
+
+ if (strcmp(val, "1") == 0 || strcmp(val, "true") == 0)
+ op->set = 1;
+ else if (strcmp(val, "0") == 0 || strcmp(val, "false") == 0)
+ op->set = 0;
+ free(op_val);
+
+ return 0;
+}
+
+/**
+ * tep_plugin_list_options - get list of plugin options
+ *
+ * Returns an array of char strings that list the currently registered
+ * plugin options in the format of <plugin>:<option>. This list can be
+ * used by toggling the option.
+ *
+ * Returns NULL if there's no options registered. On error it returns
+ * INVALID_PLUGIN_LIST_OPTION
+ *
+ * Must be freed with tep_plugin_free_options_list().
+ */
+char **tep_plugin_list_options(void)
+{
+ struct registered_plugin_options *reg;
+ struct tep_plugin_option *op;
+ char **list = NULL;
+ char *name;
+ int count = 0;
+
+ for (reg = registered_options; reg; reg = reg->next) {
+ for (op = reg->options; op->name; op++) {
+ char *alias = op->plugin_alias ? op->plugin_alias : op->file;
+ char **temp = list;
+ int ret;
+
+ ret = asprintf(&name, "%s:%s", alias, op->name);
+ if (ret < 0)
+ goto err;
+
+ list = realloc(list, count + 2);
+ if (!list) {
+ list = temp;
+ free(name);
+ goto err;
+ }
+ list[count++] = name;
+ list[count] = NULL;
+ }
+ }
+ return list;
+
+ err:
+ while (--count >= 0)
+ free(list[count]);
+ free(list);
+
+ return INVALID_PLUGIN_LIST_OPTION;
+}
+
+void tep_plugin_free_options_list(char **list)
+{
+ int i;
+
+ if (!list)
+ return;
+
+ if (list == INVALID_PLUGIN_LIST_OPTION)
+ return;
+
+ for (i = 0; list[i]; i++)
+ free(list[i]);
+
+ free(list);
+}
+
+static int
+update_option(const char *file, struct tep_plugin_option *option)
+{
+ struct trace_plugin_options *op;
+ char *plugin;
+ int ret = 0;
+
+ if (option->plugin_alias) {
+ plugin = strdup(option->plugin_alias);
+ if (!plugin)
+ return -1;
+ } else {
+ char *p;
+ plugin = strdup(file);
+ if (!plugin)
+ return -1;
+ p = strstr(plugin, ".");
+ if (p)
+ *p = '\0';
+ }
+
+ /* first look for named options */
+ for (op = trace_plugin_options; op; op = op->next) {
+ if (!op->plugin)
+ continue;
+ if (strcmp(op->plugin, plugin) != 0)
+ continue;
+ if (strcmp(op->option, option->name) != 0)
+ continue;
+
+ ret = update_option_value(option, op->value);
+ if (ret)
+ goto out;
+ break;
+ }
+
+ /* first look for unnamed options */
+ for (op = trace_plugin_options; op; op = op->next) {
+ if (op->plugin)
+ continue;
+ if (strcmp(op->option, option->name) != 0)
+ continue;
+
+ ret = update_option_value(option, op->value);
+ break;
+ }
+
+ out:
+ free(plugin);
+ return ret;
+}
+
+/**
+ * tep_plugin_add_options - Add a set of options by a plugin
+ * @name: The name of the plugin adding the options
+ * @options: The set of options being loaded
+ *
+ * Sets the options with the values that have been added by user.
+ */
+int tep_plugin_add_options(const char *name,
+ struct tep_plugin_option *options)
+{
+ struct registered_plugin_options *reg;
+
+ reg = malloc(sizeof(*reg));
+ if (!reg)
+ return -1;
+ reg->next = registered_options;
+ reg->options = options;
+ registered_options = reg;
+
+ while (options->name) {
+ update_option(name, options);
+ options++;
+ }
+ return 0;
+}
+
+/**
+ * tep_plugin_remove_options - remove plugin options that were registered
+ * @options: Options to removed that were registered with tep_plugin_add_options
+ */
+void tep_plugin_remove_options(struct tep_plugin_option *options)
+{
+ struct registered_plugin_options **last;
+ struct registered_plugin_options *reg;
+
+ for (last = ®istered_options; *last; last = &(*last)->next) {
+ if ((*last)->options == options) {
+ reg = *last;
+ *last = reg->next;
+ free(reg);
+ return;
+ }
+ }
+}
+
+/**
+ * tep_print_plugins - print out the list of plugins loaded
+ * @s: the trace_seq descripter to write to
+ * @prefix: The prefix string to add before listing the option name
+ * @suffix: The suffix string ot append after the option name
+ * @list: The list of plugins (usually returned by tep_load_plugins()
+ *
+ * Writes to the trace_seq @s the list of plugins (files) that is
+ * returned by tep_load_plugins(). Use @prefix and @suffix for formating:
+ * @prefix = " ", @suffix = "\n".
+ */
+void tep_print_plugins(struct trace_seq *s,
+ const char *prefix, const char *suffix,
+ const struct plugin_list *list)
+{
+ while (list) {
+ trace_seq_printf(s, "%s%s%s", prefix, list->name, suffix);
+ list = list->next;
+ }
+}
+
+static void
+load_plugin(struct tep_handle *pevent, const char *path,
+ const char *file, void *data)
+{
+ struct plugin_list **plugin_list = data;
+ tep_plugin_load_func func;
+ struct plugin_list *list;
+ const char *alias;
+ char *plugin;
+ void *handle;
+ int ret;
+
+ ret = asprintf(&plugin, "%s/%s", path, file);
+ if (ret < 0) {
+ warning("could not allocate plugin memory\n");
+ return;
+ }
+
+ handle = dlopen(plugin, RTLD_NOW | RTLD_GLOBAL);
+ if (!handle) {
+ warning("could not load plugin '%s'\n%s\n",
+ plugin, dlerror());
+ goto out_free;
+ }
+
+ alias = dlsym(handle, TEP_PLUGIN_ALIAS_NAME);
+ if (!alias)
+ alias = file;
+
+ func = dlsym(handle, TEP_PLUGIN_LOADER_NAME);
+ if (!func) {
+ warning("could not find func '%s' in plugin '%s'\n%s\n",
+ TEP_PLUGIN_LOADER_NAME, plugin, dlerror());
+ goto out_free;
+ }
+
+ list = malloc(sizeof(*list));
+ if (!list) {
+ warning("could not allocate plugin memory\n");
+ goto out_free;
+ }
+
+ list->next = *plugin_list;
+ list->handle = handle;
+ list->name = plugin;
+ *plugin_list = list;
+
+ pr_stat("registering plugin: %s", plugin);
+ func(pevent);
+ return;
+
+ out_free:
+ free(plugin);
+}
+
+static void
+load_plugins_dir(struct tep_handle *pevent, const char *suffix,
+ const char *path,
+ void (*load_plugin)(struct tep_handle *pevent,
+ const char *path,
+ const char *name,
+ void *data),
+ void *data)
+{
+ struct dirent *dent;
+ struct stat st;
+ DIR *dir;
+ int ret;
+
+ ret = stat(path, &st);
+ if (ret < 0)
+ return;
+
+ if (!S_ISDIR(st.st_mode))
+ return;
+
+ dir = opendir(path);
+ if (!dir)
+ return;
+
+ while ((dent = readdir(dir))) {
+ const char *name = dent->d_name;
+
+ if (strcmp(name, ".") == 0 ||
+ strcmp(name, "..") == 0)
+ continue;
+
+ /* Only load plugins that end in suffix */
+ if (strcmp(name + (strlen(name) - strlen(suffix)), suffix) != 0)
+ continue;
+
+ load_plugin(pevent, path, name, data);
+ }
+
+ closedir(dir);
+}
+
+static void
+load_plugins(struct tep_handle *pevent, const char *suffix,
+ void (*load_plugin)(struct tep_handle *pevent,
+ const char *path,
+ const char *name,
+ void *data),
+ void *data)
+{
+ char *home;
+ char *path;
+ char *envdir;
+ int ret;
+
+ if (pevent->flags & TEP_DISABLE_PLUGINS)
+ return;
+
+ /*
+ * If a system plugin directory was defined,
+ * check that first.
+ */
+#ifdef PLUGIN_DIR
+ if (!(pevent->flags & TEP_DISABLE_SYS_PLUGINS))
+ load_plugins_dir(pevent, suffix, PLUGIN_DIR,
+ load_plugin, data);
+#endif
+
+ /*
+ * Next let the environment-set plugin directory
+ * override the system defaults.
+ */
+ envdir = getenv("TRACEEVENT_PLUGIN_DIR");
+ if (envdir)
+ load_plugins_dir(pevent, suffix, envdir, load_plugin, data);
+
+ /*
+ * Now let the home directory override the environment
+ * or system defaults.
+ */
+ home = getenv("HOME");
+ if (!home)
+ return;
+
+ ret = asprintf(&path, "%s/%s", home, LOCAL_PLUGIN_DIR);
+ if (ret < 0) {
+ warning("could not allocate plugin memory\n");
+ return;
+ }
+
+ load_plugins_dir(pevent, suffix, path, load_plugin, data);
+
+ free(path);
+}
+
+struct plugin_list*
+tep_load_plugins(struct tep_handle *pevent)
+{
+ struct plugin_list *list = NULL;
+
+ load_plugins(pevent, ".so", load_plugin, &list);
+ return list;
+}
+
+void
+tep_unload_plugins(struct plugin_list *plugin_list, struct tep_handle *pevent)
+{
+ tep_plugin_unload_func func;
+ struct plugin_list *list;
+
+ while (plugin_list) {
+ list = plugin_list;
+ plugin_list = list->next;
+ func = dlsym(list->handle, TEP_PLUGIN_UNLOADER_NAME);
+ if (func)
+ func(pevent);
+ dlclose(list->handle);
+ free(list->name);
+ free(list);
+ }
+}