tools lib traceevent: Add plugin support (c877bbd8) · Commits · 戴 / test

tools/lib/traceevent/Makefile

+5 −1

Original line number	Diff line number	Diff line
		@@ -180,7 +180,11 @@ $(obj)/%.o: $(src)/%.c
		%.o: $(src)/%.c
		$(Q)$(call do_compile)

		PEVENT_LIB_OBJS = event-parse.o trace-seq.o parse-filter.o parse-utils.o
		PEVENT_LIB_OBJS = event-parse.o
		PEVENT_LIB_OBJS += event-plugin.o
		PEVENT_LIB_OBJS += trace-seq.o
		PEVENT_LIB_OBJS += parse-filter.o
		PEVENT_LIB_OBJS += parse-utils.o
		PEVENT_LIB_OBJS += kbuffer-parse.o

		ALL_OBJS = $(PEVENT_LIB_OBJS)

tools/lib/traceevent/event-parse.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -377,6 +377,11 @@ enum pevent_errno {
		};
		#undef _PE

		struct plugin_list;

		struct plugin_list traceevent_load_plugins(struct pevent pevent);
		void traceevent_unload_plugins(struct plugin_list *plugin_list);

		struct cmdline;
		struct cmdline_list;
		struct func_map;

tools/lib/traceevent/event-plugin.c

0 → 100644

+202 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
		*
		* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of the GNU Lesser General Public
		* License as published by the Free Software Foundation;
		* version 2.1 of the License (not later!)
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU Lesser General Public License for more details.
		*
		* You should have received a copy of the GNU Lesser General Public
		* License along with this program; if not, see <http://www.gnu.org/licenses>
		*
		* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		*/

		#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"

		struct plugin_list {
		struct plugin_list *next;
		char *name;
		void *handle;
		};

		static void
		load_plugin(struct pevent pevent, const char path,
		const char file, void data)
		{
		struct plugin_list **plugin_list = data;
		pevent_plugin_load_func func;
		struct plugin_list *list;
		const char *alias;
		char *plugin;
		void *handle;

		plugin = malloc_or_die(strlen(path) + strlen(file) + 2);

		strcpy(plugin, path);
		strcat(plugin, "/");
		strcat(plugin, file);

		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, PEVENT_PLUGIN_ALIAS_NAME);
		if (!alias)
		alias = file;

		func = dlsym(handle, PEVENT_PLUGIN_LOADER_NAME);
		if (!func) {
		warning("could not find func '%s' in plugin '%s'\n%s\n",
		PEVENT_PLUGIN_LOADER_NAME, plugin, dlerror());
		goto out_free;
		}

		list = malloc_or_die(sizeof(*list));
		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 pevent pevent, const char suffix,
		const char *path,
		void (load_plugin)(struct pevent 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 pevent pevent, const char suffix,
		void (load_plugin)(struct pevent pevent,
		const char *path,
		const char *name,
		void *data),
		void *data)
		{
		char *home;
		char *path;
		char *envdir;

		/*
		* If a system plugin directory was defined,
		* check that first.
		*/
		#ifdef PLUGIN_DIR
		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;

		path = malloc_or_die(strlen(home) + strlen(LOCAL_PLUGIN_DIR) + 2);

		strcpy(path, home);
		strcat(path, "/");
		strcat(path, LOCAL_PLUGIN_DIR);

		load_plugins_dir(pevent, suffix, path, load_plugin, data);

		free(path);
		}

		struct plugin_list*
		traceevent_load_plugins(struct pevent *pevent)
		{
		struct plugin_list *list = NULL;

		load_plugins(pevent, ".so", load_plugin, &list);
		return list;
		}

		void
		traceevent_unload_plugins(struct plugin_list *plugin_list)
		{
		pevent_plugin_unload_func func;
		struct plugin_list *list;

		while (plugin_list) {
		list = plugin_list;
		plugin_list = list->next;
		func = dlsym(list->handle, PEVENT_PLUGIN_UNLOADER_NAME);
		if (func)
		func();
		dlclose(list->handle);
		free(list->name);
		free(list);
		}
		}

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