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-rw-r--r--tools/lib/traceevent/event-plugin.c711
1 files changed, 711 insertions, 0 deletions
diff --git a/tools/lib/traceevent/event-plugin.c b/tools/lib/traceevent/event-plugin.c
new file mode 100644
index 000000000..e7f93d5fe
--- /dev/null
+++ b/tools/lib/traceevent/event-plugin.c
@@ -0,0 +1,711 @@
+// 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 <errno.h>
+#include "event-parse.h"
+#include "event-parse-local.h"
+#include "event-utils.h"
+#include "trace-seq.h"
+
+#define LOCAL_PLUGIN_DIR ".local/lib/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 tep_plugin_list {
+ struct tep_plugin_list *next;
+ char *name;
+ void *handle;
+};
+
+struct tep_plugins_dir {
+ struct tep_plugins_dir *next;
+ char *path;
+ enum tep_plugin_load_priority prio;
+};
+
+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 = &registered_options; *last; last = &(*last)->next) {
+ if ((*last)->options == options) {
+ reg = *last;
+ *last = reg->next;
+ free(reg);
+ return;
+ }
+ }
+}
+
+static int parse_option_name(char **option, char **plugin)
+{
+ char *p;
+
+ *plugin = NULL;
+
+ if ((p = strstr(*option, ":"))) {
+ *plugin = *option;
+ *p = '\0';
+ *option = strdup(p + 1);
+ if (!*option)
+ return -1;
+ }
+ return 0;
+}
+
+static struct tep_plugin_option *
+find_registered_option(const char *plugin, const char *option)
+{
+ struct registered_plugin_options *reg;
+ struct tep_plugin_option *op;
+ const char *op_plugin;
+
+ for (reg = registered_options; reg; reg = reg->next) {
+ for (op = reg->options; op->name; op++) {
+ if (op->plugin_alias)
+ op_plugin = op->plugin_alias;
+ else
+ op_plugin = op->file;
+
+ if (plugin && strcmp(plugin, op_plugin) != 0)
+ continue;
+ if (strcmp(option, op->name) != 0)
+ continue;
+
+ return op;
+ }
+ }
+
+ return NULL;
+}
+
+static int process_option(const char *plugin, const char *option, const char *val)
+{
+ struct tep_plugin_option *op;
+
+ op = find_registered_option(plugin, option);
+ if (!op)
+ return 0;
+
+ return update_option_value(op, val);
+}
+
+/**
+ * tep_plugin_add_option - add an option/val pair to set plugin options
+ * @name: The name of the option (format: <plugin>:<option> or just <option>)
+ * @val: (optional) the value for the option
+ *
+ * Modify a plugin option. If @val is given than the value of the option
+ * is set (note, some options just take a boolean, so @val must be either
+ * "1" or "0" or "true" or "false").
+ */
+int tep_plugin_add_option(const char *name, const char *val)
+{
+ struct trace_plugin_options *op;
+ char *option_str;
+ char *plugin;
+
+ option_str = strdup(name);
+ if (!option_str)
+ return -ENOMEM;
+
+ if (parse_option_name(&option_str, &plugin) < 0)
+ return -ENOMEM;
+
+ /* If the option exists, update the val */
+ for (op = trace_plugin_options; op; op = op->next) {
+ /* Both must be NULL or not NULL */
+ if ((!plugin || !op->plugin) && plugin != op->plugin)
+ continue;
+ if (plugin && strcmp(plugin, op->plugin) != 0)
+ continue;
+ if (strcmp(op->option, option_str) != 0)
+ continue;
+
+ /* update option */
+ free(op->value);
+ if (val) {
+ op->value = strdup(val);
+ if (!op->value)
+ goto out_free;
+ } else
+ op->value = NULL;
+
+ /* plugin and option_str don't get freed at the end */
+ free(plugin);
+ free(option_str);
+
+ plugin = op->plugin;
+ option_str = op->option;
+ break;
+ }
+
+ /* If not found, create */
+ if (!op) {
+ op = malloc(sizeof(*op));
+ if (!op)
+ goto out_free;
+ memset(op, 0, sizeof(*op));
+ op->plugin = plugin;
+ op->option = option_str;
+ if (val) {
+ op->value = strdup(val);
+ if (!op->value) {
+ free(op);
+ goto out_free;
+ }
+ }
+ op->next = trace_plugin_options;
+ trace_plugin_options = op;
+ }
+
+ return process_option(plugin, option_str, val);
+
+out_free:
+ free(plugin);
+ free(option_str);
+ return -ENOMEM;
+}
+
+static void print_op_data(struct trace_seq *s, const char *name,
+ const char *op)
+{
+ if (op)
+ trace_seq_printf(s, "%8s:\t%s\n", name, op);
+}
+
+/**
+ * tep_plugin_print_options - print out the registered plugin options
+ * @s: The trace_seq descriptor to write the plugin options into
+ *
+ * Writes a list of options into trace_seq @s.
+ */
+void tep_plugin_print_options(struct trace_seq *s)
+{
+ struct registered_plugin_options *reg;
+ struct tep_plugin_option *op;
+
+ for (reg = registered_options; reg; reg = reg->next) {
+ if (reg != registered_options)
+ trace_seq_printf(s, "============\n");
+ for (op = reg->options; op->name; op++) {
+ if (op != reg->options)
+ trace_seq_printf(s, "------------\n");
+ print_op_data(s, "file", op->file);
+ print_op_data(s, "plugin", op->plugin_alias);
+ print_op_data(s, "option", op->name);
+ print_op_data(s, "desc", op->description);
+ print_op_data(s, "value", op->value);
+ trace_seq_printf(s, "%8s:\t%d\n", "set", op->set);
+ }
+ }
+}
+
+/**
+ * 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 tep_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 *tep, const char *path,
+ const char *file, void *data)
+{
+ struct tep_plugin_list **plugin_list = data;
+ struct tep_plugin_option *options;
+ tep_plugin_load_func func;
+ struct tep_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;
+
+ options = dlsym(handle, TEP_PLUGIN_OPTIONS_NAME);
+ if (options) {
+ while (options->name) {
+ ret = update_option(alias, options);
+ if (ret < 0)
+ goto out_free;
+ options++;
+ }
+ }
+
+ 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(tep);
+ return;
+
+ out_free:
+ free(plugin);
+}
+
+static void
+load_plugins_dir(struct tep_handle *tep, const char *suffix,
+ const char *path,
+ void (*load_plugin)(struct tep_handle *tep,
+ 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(tep, path, name, data);
+ }
+
+ closedir(dir);
+}
+
+/**
+ * tep_load_plugins_hook - call a user specified callback to load a plugin
+ * @tep: handler to traceevent context
+ * @suffix: filter only plugin files with given suffix
+ * @load_plugin: user specified callback, called for each plugin file
+ * @data: custom context, passed to @load_plugin
+ *
+ * Searches for traceevent plugin files and calls @load_plugin for each
+ * The order of plugins search is:
+ * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_FIRST
+ * - Directory, specified at compile time with PLUGIN_TRACEEVENT_DIR
+ * - Directory, specified by environment variable TRACEEVENT_PLUGIN_DIR
+ * - In user's home: ~/.local/lib/traceevent/plugins/
+ * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_LAST
+ *
+ */
+void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
+ void (*load_plugin)(struct tep_handle *tep,
+ const char *path,
+ const char *name,
+ void *data),
+ void *data)
+{
+ struct tep_plugins_dir *dir = NULL;
+ char *home;
+ char *path;
+ char *envdir;
+ int ret;
+
+ if (tep && tep->flags & TEP_DISABLE_PLUGINS)
+ return;
+
+ if (tep)
+ dir = tep->plugins_dir;
+ while (dir) {
+ if (dir->prio == TEP_PLUGIN_FIRST)
+ load_plugins_dir(tep, suffix, dir->path,
+ load_plugin, data);
+ dir = dir->next;
+ }
+
+ /*
+ * If a system plugin directory was defined,
+ * check that first.
+ */
+#ifdef PLUGIN_DIR
+ if (!tep || !(tep->flags & TEP_DISABLE_SYS_PLUGINS))
+ load_plugins_dir(tep, 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(tep, 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(tep, suffix, path, load_plugin, data);
+
+ if (tep)
+ dir = tep->plugins_dir;
+ while (dir) {
+ if (dir->prio == TEP_PLUGIN_LAST)
+ load_plugins_dir(tep, suffix, dir->path,
+ load_plugin, data);
+ dir = dir->next;
+ }
+
+ free(path);
+}
+
+struct tep_plugin_list*
+tep_load_plugins(struct tep_handle *tep)
+{
+ struct tep_plugin_list *list = NULL;
+
+ tep_load_plugins_hook(tep, ".so", load_plugin, &list);
+ return list;
+}
+
+/**
+ * tep_add_plugin_path - Add a new plugin directory.
+ * @tep: Trace event handler.
+ * @path: Path to a directory. All plugin files in that
+ * directory will be loaded.
+ *@prio: Load priority of the plugins in that directory.
+ *
+ * Returns -1 in case of an error, 0 otherwise.
+ */
+int tep_add_plugin_path(struct tep_handle *tep, char *path,
+ enum tep_plugin_load_priority prio)
+{
+ struct tep_plugins_dir *dir;
+
+ if (!tep || !path)
+ return -1;
+
+ dir = calloc(1, sizeof(*dir));
+ if (!dir)
+ return -1;
+
+ dir->path = strdup(path);
+ if (!dir->path) {
+ free(dir);
+ return -1;
+ }
+ dir->prio = prio;
+ dir->next = tep->plugins_dir;
+ tep->plugins_dir = dir;
+
+ return 0;
+}
+
+__hidden void free_tep_plugin_paths(struct tep_handle *tep)
+{
+ struct tep_plugins_dir *dir;
+
+ if (!tep)
+ return;
+
+ dir = tep->plugins_dir;
+ while (dir) {
+ tep->plugins_dir = tep->plugins_dir->next;
+ free(dir->path);
+ free(dir);
+ dir = tep->plugins_dir;
+ }
+}
+
+void
+tep_unload_plugins(struct tep_plugin_list *plugin_list, struct tep_handle *tep)
+{
+ tep_plugin_unload_func func;
+ struct tep_plugin_list *list;
+
+ while (plugin_list) {
+ list = plugin_list;
+ plugin_list = list->next;
+ func = dlsym(list->handle, TEP_PLUGIN_UNLOADER_NAME);
+ if (func)
+ func(tep);
+ dlclose(list->handle);
+ free(list->name);
+ free(list);
+ }
+}