[PATCH v3 0/5] Remove redundant trace-cmd plugin handling logic

[PATCH v3 0/5] Remove redundant trace-cmd plugin handling logic

[Tzvetomir Stoyanov (VMware)]

Currently there are no trace-cmd related plugins, all of them
are designed to be used with libtraceeevnt. As both libtraceevent
and trace-cmd have logic for managing plugins, the one in trace-cmd
is redundant. Those redundant code is removed and replaced with calls
to libtraceeevnt plugin APIs. When trace-cmd has to load any plugins,
it uses libtraceeevnt to do the job.

All existing plugins are moved from plugins/ to lib/traceevent/plugins
directory, as all of them are designed to be used with the traceevent
library.

An initial infrastructure for trace-cmd specific plugins is added - 
new lib/trace-cmd/plugins directory and initial set of APIs
for working with trace-cmd plugins.

Tzvetomir Stoyanov (1):
  trace-cmd: Change plugin install directories

Tzvetomir Stoyanov (VMware) (4):
  trace-cmd: Move libtraceevent plugins in its own directory.
  trace-cmd: Rename plugin_python to plugin_python_loader.
  trace-cmd: Load libtraceevent plugins from build folder, if exists.
  trace-cmd: Add initial infrastructure for trace-cmd specific plugins.

 .gitignore                                    |   4 +-
 Makefile                                      |  83 +++--
 include/trace-cmd/trace-cmd.h                 |  44 ++-
 lib/trace-cmd/Makefile                        |   3 +-
 lib/trace-cmd/plugins/Makefile                |  58 ++++
 lib/trace-cmd/trace-plugin.c                  | 313 ++++++++++++++++++
 lib/traceevent/event-plugin.c                 |  34 +-
 {plugins => lib/traceevent/plugins}/Makefile  |  16 +-
 .../traceevent/plugins}/plugin_blk.c          |   0
 .../traceevent/plugins}/plugin_cfg80211.c     |   0
 .../traceevent/plugins}/plugin_function.c     |   0
 .../traceevent/plugins}/plugin_futex.c        |   0
 .../traceevent/plugins}/plugin_hrtimer.c      |   0
 .../traceevent/plugins}/plugin_jbd2.c         |   0
 .../traceevent/plugins}/plugin_kmem.c         |   0
 .../traceevent/plugins}/plugin_kvm.c          |   0
 .../traceevent/plugins}/plugin_mac80211.c     |   0
 .../traceevent/plugins/plugin_python_loader.c |   0
 .../traceevent/plugins}/plugin_sched_switch.c |   0
 .../traceevent/plugins}/plugin_scsi.c         |   0
 .../traceevent/plugins}/plugin_tlb.c          |   0
 .../traceevent/plugins}/plugin_xen.c          |   0
 22 files changed, 505 insertions(+), 50 deletions(-)
 create mode 100644 lib/trace-cmd/plugins/Makefile
 create mode 100644 lib/trace-cmd/trace-plugin.c
 rename {plugins => lib/traceevent/plugins}/Makefile (81%)
 rename {plugins => lib/traceevent/plugins}/plugin_blk.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_cfg80211.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_function.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_futex.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_hrtimer.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_jbd2.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_kmem.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_kvm.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_mac80211.c (100%)
 rename plugins/plugin_python.c => lib/traceevent/plugins/plugin_python_loader.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_sched_switch.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_scsi.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_tlb.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_xen.c (100%)

-- 
2.21.0

[PATCH v3 1/5] trace-cmd: Move libtraceevent plugins in its own directory.

[Tzvetomir Stoyanov (VMware)]

All existing plugins are moved from plugins/ to plugins/traceevent/
directory, as all of them (except plugin_python) are designed to be
used with the traceevent library. This change paves the way for
implementing trace-cmd specific plugins.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .gitignore                                    |  2 +-
 Makefile                                      | 28 +++++++++----------
 lib/trace-cmd/Makefile                        |  2 --
 {plugins => lib/traceevent/plugins}/Makefile  |  6 ++--
 .../traceevent/plugins}/plugin_blk.c          |  0
 .../traceevent/plugins}/plugin_cfg80211.c     |  0
 .../traceevent/plugins}/plugin_function.c     |  0
 .../traceevent/plugins}/plugin_futex.c        |  0
 .../traceevent/plugins}/plugin_hrtimer.c      |  0
 .../traceevent/plugins}/plugin_jbd2.c         |  0
 .../traceevent/plugins}/plugin_kmem.c         |  0
 .../traceevent/plugins}/plugin_kvm.c          |  0
 .../traceevent/plugins}/plugin_mac80211.c     |  0
 .../traceevent/plugins}/plugin_python.c       |  0
 .../traceevent/plugins}/plugin_sched_switch.c |  0
 .../traceevent/plugins}/plugin_scsi.c         |  0
 .../traceevent/plugins}/plugin_tlb.c          |  0
 .../traceevent/plugins}/plugin_xen.c          |  0
 18 files changed, 18 insertions(+), 20 deletions(-)
 rename {plugins => lib/traceevent/plugins}/Makefile (93%)
 rename {plugins => lib/traceevent/plugins}/plugin_blk.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_cfg80211.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_function.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_futex.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_hrtimer.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_jbd2.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_kmem.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_kvm.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_mac80211.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_python.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_sched_switch.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_scsi.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_tlb.c (100%)
 rename {plugins => lib/traceevent/plugins}/plugin_xen.c (100%)

diff --git a/.gitignore b/.gitignore
index b7b405f..20bb5a3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,5 +18,5 @@ ctracecmdgui_wrap.c
 tags
 TAGS
 cscope*
-trace_plugin_dir
+traceevent_plugin_dir
 trace_python_dir
diff --git a/Makefile b/Makefile
index dabdf8d..f336f7a 100644
--- a/Makefile
+++ b/Makefile
@@ -273,16 +273,16 @@ gui: force $(CMD_TARGETS) $(kshark-dir)/build/Makefile
 trace-cmd: force $(LIBTRACEEVENT_STATIC) $(LIBTRACECMD_STATIC)
 	$(Q)$(MAKE) -C $(src)/tracecmd $(obj)/tracecmd/$@
 
-$(LIBTRACEEVENT_SHARED): force
+$(LIBTRACEEVENT_SHARED): force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
 	$(Q)$(MAKE) -C $(src)/lib/traceevent $@
 
-$(LIBTRACEEVENT_STATIC): force
+$(LIBTRACEEVENT_STATIC): force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
 	$(Q)$(MAKE) -C $(src)/lib/traceevent $@
 
-$(LIBTRACECMD_STATIC): force $(obj)/plugins/trace_plugin_dir
+$(LIBTRACECMD_STATIC): force
 	$(Q)$(MAKE) -C $(src)/lib/trace-cmd $@
 
-$(LIBTRACECMD_SHARED): force $(obj)/plugins/trace_plugin_dir
+$(LIBTRACECMD_SHARED): force
 	$(Q)$(MAKE) -C $(src)/lib/trace-cmd $@
 
 libtraceevent.so: $(LIBTRACEEVENT_SHARED)
@@ -292,14 +292,14 @@ libtracecmd.so: $(LIBTRACECMD_SHARED)
 
 libs: $(LIBTRACECMD_SHARED) $(LIBTRACEEVENT_SHARED)
 
-plugins: force $(obj)/plugins/trace_plugin_dir $(obj)/plugins/trace_python_dir
-	$(Q)$(MAKE) -C $(src)/plugins
+plugins: force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir $(obj)/lib/traceevent/plugins/trace_python_dir
+	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins
 
-$(obj)/plugins/trace_plugin_dir: force
-	$(Q)$(MAKE) -C $(src)/plugins $@
+$(obj)/lib/traceevent/plugins/traceevent_plugin_dir: force
+	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $@
 
-$(obj)/plugins/trace_python_dir: force
-	$(Q)$(MAKE) -C $(src)/plugins $@
+$(obj)/lib/traceevent/plugins/trace_python_dir: force
+	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $@
 
 show_gui_make:
 	@echo "Note: to build the gui, type \"make gui\""
@@ -325,7 +325,7 @@ cscope: force
 	$(call find_tag_files) | cscope -b -q
 
 install_plugins: force
-	$(Q)$(MAKE) -C $(src)/plugins $@
+	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $@
 
 install_python: force
 	$(Q)$(MAKE) -C $(src)/python $@
@@ -372,7 +372,7 @@ clean:
 	$(RM) tags TAGS cscope*
 	$(MAKE) -C $(src)/lib/traceevent clean
 	$(MAKE) -C $(src)/lib/trace-cmd clean
-	$(MAKE) -C $(src)/plugins clean
+	$(MAKE) -C $(src)/lib/traceevent/plugins clean
 	$(MAKE) -C $(src)/python clean
 	$(MAKE) -C $(src)/tracecmd clean
 	if [ -f $(kshark-dir)/build/Makefile ]; then $(MAKE) -C $(kshark-dir)/build clean; fi
@@ -421,8 +421,8 @@ python-gui: $(PYTHON_GUI)
 PHONY += python-plugin
 python-plugin: $(PYTHON_PLUGINS)
 
-plugin_python.so: force $(obj)/plugins/trace_python_dir
-	$(Q)$(MAKE) -C $(src)/plugins $(obj)/plugins/plugin_python.so
+plugin_python.so: force $(obj)/lib/traceevent/plugins/trace_python_dir
+	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $(obj)/lib/traceevent/plugins/plugin_python.so
 
 dist:
 	git archive --format=tar --prefix=trace-cmd-$(TRACECMD_VERSION)/ HEAD \
diff --git a/lib/trace-cmd/Makefile b/lib/trace-cmd/Makefile
index 78875e4..3b4b5aa 100644
--- a/lib/trace-cmd/Makefile
+++ b/lib/trace-cmd/Makefile
@@ -40,8 +40,6 @@ $(bdir)/libtracecmd.so: $(OBJS)
 $(bdir)/%.o: %.c
 	$(Q)$(call do_fpic_compile)
 
-$(bdir)/trace-util.o: $(obj)/plugins/trace_plugin_dir
-
 $(DEPS): $(bdir)/.%.d: %.c
 	$(Q)$(CC) -M $(CPPFLAGS) $(CFLAGS) $< > $@
 
diff --git a/plugins/Makefile b/lib/traceevent/plugins/Makefile
similarity index 93%
rename from plugins/Makefile
rename to lib/traceevent/plugins/Makefile
index 4598e83..e0a7566 100644
--- a/plugins/Makefile
+++ b/lib/traceevent/plugins/Makefile
@@ -1,6 +1,6 @@
 include $(src)/scripts/utils.mk
 
-bdir:=$(obj)/plugins
+bdir:=$(obj)/lib/traceevent/plugins
 
 PLUGIN_OBJS =
 PLUGIN_OBJS += plugin_jbd2.o
@@ -61,7 +61,7 @@ install_plugins: $(PLUGINS_INSTALL)
 # and $(PYTHON_DIR) change. Without them, a full clean build would necessary
 # in order to get the binaries updated.
 
-$(bdir)/trace_plugin_dir: $(bdir) force
+$(bdir)/traceevent_plugin_dir: $(bdir) force
 	$(Q)$(N)$(call update_dir, 'PLUGIN_DIR=$(PLUGIN_DIR)')
 
 $(bdir)/trace_python_dir: $(bdir) force
@@ -75,7 +75,7 @@ ifneq ($(dep_includes),)
 endif
 
 clean:
-	$(RM) -f $(bdir)/*.a $(bdir)/*.so $(bdir)/*.o $(bdir)/.*.d $(bdir)/trace_plugin_dir $(bdir)/trace_python_dir
+	$(RM) -f $(bdir)/*.a $(bdir)/*.so $(bdir)/*.o $(bdir)/.*.d $(bdir)/traceevent_plugin_dir $(bdir)/trace_python_dir
 
 force:
 .PHONY: clean force
diff --git a/plugins/plugin_blk.c b/lib/traceevent/plugins/plugin_blk.c
similarity index 100%
rename from plugins/plugin_blk.c
rename to lib/traceevent/plugins/plugin_blk.c
diff --git a/plugins/plugin_cfg80211.c b/lib/traceevent/plugins/plugin_cfg80211.c
similarity index 100%
rename from plugins/plugin_cfg80211.c
rename to lib/traceevent/plugins/plugin_cfg80211.c
diff --git a/plugins/plugin_function.c b/lib/traceevent/plugins/plugin_function.c
similarity index 100%
rename from plugins/plugin_function.c
rename to lib/traceevent/plugins/plugin_function.c
diff --git a/plugins/plugin_futex.c b/lib/traceevent/plugins/plugin_futex.c
similarity index 100%
rename from plugins/plugin_futex.c
rename to lib/traceevent/plugins/plugin_futex.c
diff --git a/plugins/plugin_hrtimer.c b/lib/traceevent/plugins/plugin_hrtimer.c
similarity index 100%
rename from plugins/plugin_hrtimer.c
rename to lib/traceevent/plugins/plugin_hrtimer.c
diff --git a/plugins/plugin_jbd2.c b/lib/traceevent/plugins/plugin_jbd2.c
similarity index 100%
rename from plugins/plugin_jbd2.c
rename to lib/traceevent/plugins/plugin_jbd2.c
diff --git a/plugins/plugin_kmem.c b/lib/traceevent/plugins/plugin_kmem.c
similarity index 100%
rename from plugins/plugin_kmem.c
rename to lib/traceevent/plugins/plugin_kmem.c
diff --git a/plugins/plugin_kvm.c b/lib/traceevent/plugins/plugin_kvm.c
similarity index 100%
rename from plugins/plugin_kvm.c
rename to lib/traceevent/plugins/plugin_kvm.c
diff --git a/plugins/plugin_mac80211.c b/lib/traceevent/plugins/plugin_mac80211.c
similarity index 100%
rename from plugins/plugin_mac80211.c
rename to lib/traceevent/plugins/plugin_mac80211.c
diff --git a/plugins/plugin_python.c b/lib/traceevent/plugins/plugin_python.c
similarity index 100%
rename from plugins/plugin_python.c
rename to lib/traceevent/plugins/plugin_python.c
diff --git a/plugins/plugin_sched_switch.c b/lib/traceevent/plugins/plugin_sched_switch.c
similarity index 100%
rename from plugins/plugin_sched_switch.c
rename to lib/traceevent/plugins/plugin_sched_switch.c
diff --git a/plugins/plugin_scsi.c b/lib/traceevent/plugins/plugin_scsi.c
similarity index 100%
rename from plugins/plugin_scsi.c
rename to lib/traceevent/plugins/plugin_scsi.c
diff --git a/plugins/plugin_tlb.c b/lib/traceevent/plugins/plugin_tlb.c
similarity index 100%
rename from plugins/plugin_tlb.c
rename to lib/traceevent/plugins/plugin_tlb.c
diff --git a/plugins/plugin_xen.c b/lib/traceevent/plugins/plugin_xen.c
similarity index 100%
rename from plugins/plugin_xen.c
rename to lib/traceevent/plugins/plugin_xen.c
-- 
2.21.0

[PATCH v3 2/5] trace-cmd: Rename plugin_python to plugin_python_loader.

[Tzvetomir Stoyanov (VMware)]

The plugin_python is renamed to plugin_python_loader, to make
the name more closer to the actual plugin role.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 Makefile                                               | 10 +---------
 lib/traceevent/plugins/Makefile                        |  6 +++---
 .../{plugin_python.c => plugin_python_loader.c}        |  0
 3 files changed, 4 insertions(+), 12 deletions(-)
 rename lib/traceevent/plugins/{plugin_python.c => plugin_python_loader.c} (100%)

diff --git a/Makefile b/Makefile
index f336f7a..e20eced 100644
--- a/Makefile
+++ b/Makefile
@@ -116,8 +116,7 @@ PYTHON_PKGCONFIG_VERS ?= $(PYTHON_VERS)
 
 # Can build python?
 ifeq ($(shell sh -c "pkg-config --cflags $(PYTHON_PKGCONFIG_VERS) > /dev/null 2>&1 && echo y"), y)
-	PYTHON_PLUGINS := plugin_python.so
-	BUILD_PYTHON := $(PYTHON) $(PYTHON_PLUGINS)
+	BUILD_PYTHON := $(PYTHON)
 	BUILD_PYTHON_WORKS := 1
 else
 	BUILD_PYTHON := report_nopythondev
@@ -125,7 +124,6 @@ else
 endif
 endif # NO_PYTHON
 
-export PYTHON_PLUGINS
 export BUILD_PYTHON_WORKS
 export NO_PYTHON
 
@@ -418,12 +416,6 @@ python: $(PYTHON)
 PHONY += python-gui
 python-gui: $(PYTHON_GUI)
 
-PHONY += python-plugin
-python-plugin: $(PYTHON_PLUGINS)
-
-plugin_python.so: force $(obj)/lib/traceevent/plugins/trace_python_dir
-	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $(obj)/lib/traceevent/plugins/plugin_python.so
-
 dist:
 	git archive --format=tar --prefix=trace-cmd-$(TRACECMD_VERSION)/ HEAD \
 		> ../trace-cmd-$(TRACECMD_VERSION).tar
diff --git a/lib/traceevent/plugins/Makefile b/lib/traceevent/plugins/Makefile
index e0a7566..061d919 100644
--- a/lib/traceevent/plugins/Makefile
+++ b/lib/traceevent/plugins/Makefile
@@ -21,7 +21,7 @@ PLUGIN_OBJS := $(PLUGIN_OBJS:%.o=$(bdir)/%.o)
 PLUGIN_BUILD := $(PLUGIN_OBJS:$(bdir)/%.o=$(bdir)/%.so)
 PLUGINS := $(PLUGIN_BUILD)
 ifndef NO_PYTHON
-PLUGINS += $(bdir)/plugin_python.so
+PLUGINS += $(bdir)/plugin_python_loader.so
 endif
 DEPS := $(PLUGIN_OBJS:$(bdir)/%.o=$(bdir)/.%.d)
 
@@ -44,10 +44,10 @@ $(DEPS): $(bdir)/.%.d: %.c
 
 $(PLUGIN_OBJS): $(bdir)/%.o : $(bdir)/.%.d
 
-$(bdir)/plugin_python.o: $(bdir)/%.o : %.c $(bdir)/trace_python_dir
+$(bdir)/plugin_python_loader.o: $(bdir)/%.o : %.c $(bdir)/trace_python_dir
 	$(Q)$(do_compile_python_plugin_obj)
 
-$(bdir)/plugin_python.so: $(bdir)/%.so: $(bdir)/%.o
+$(bdir)/plugin_python_loader.so: $(bdir)/%.so: $(bdir)/%.o
 	$(Q)$(do_python_plugin_build)
 
 PLUGINS_INSTALL = $(subst .so,.install,$(PLUGINS))
diff --git a/lib/traceevent/plugins/plugin_python.c b/lib/traceevent/plugins/plugin_python_loader.c
similarity index 100%
rename from lib/traceevent/plugins/plugin_python.c
rename to lib/traceevent/plugins/plugin_python_loader.c
-- 
2.21.0

[PATCH v3 3/5] trace-cmd: Load libtraceevent plugins from build folder, if exists.

[Tzvetomir Stoyanov (VMware)]

When a development version of trace-cmd is built and run on the machine,
by default it loads only installed plugins, from system drierctories.
Thus, the development plugins will not be loaded. To simplify the development
process, a new logic is added:
  At plugins load time, check the location of trace-cmd application and look
  for "plugins" directory around it. If found, load plugins from it. Those
  pluigins will be loaded last, so in case of duplication the "development"
  plugins win.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 lib/traceevent/event-plugin.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/lib/traceevent/event-plugin.c b/lib/traceevent/event-plugin.c
index bc10205..4fc4ee3 100644
--- a/lib/traceevent/event-plugin.c
+++ b/lib/traceevent/event-plugin.c
@@ -14,6 +14,7 @@
 #include <unistd.h>
 #include <dirent.h>
 #include <errno.h>
+#include <libgen.h>
 #include "event-parse.h"
 #include "event-parse-local.h"
 #include "event-utils.h"
@@ -538,6 +539,27 @@ load_plugins_dir(struct tep_handle *tep, const char *suffix,
 	closedir(dir);
 }
 
+static char *get_source_plugins_dir(void)
+{
+	char *p, path[PATH_MAX+1];
+	int ret;
+
+	ret = readlink("/proc/self/exe", path, PATH_MAX);
+	if (ret > PATH_MAX || ret < 0)
+		return NULL;
+
+	dirname(path);
+	p = strrchr(path, '/');
+	if (!p)
+		return NULL;
+	/* Check if we are in the the source tree */
+	if (strcmp(p, "/tracecmd") != 0)
+		return NULL;
+
+	strcpy(p, "/lib/traceevent/plugins");
+	return strdup(path);
+}
+
 void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
 			   void (*load_plugin)(struct tep_handle *tep,
 					       const char *path,
@@ -588,6 +610,12 @@ void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
 	load_plugins_dir(tep, suffix, path, load_plugin, data);
 
 	free(path);
+
+	path = get_source_plugins_dir();
+	if (path) {
+		load_plugins_dir(tep, suffix, path, load_plugin, data);
+		free(path);
+	}
 }
 
 struct tep_plugin_list*
-- 
2.21.0

[PATCH v3 4/5] trace-cmd: Change plugin install directories

[Tzvetomir Stoyanov (VMware)]

From: Tzvetomir Stoyanov <tstoyanov@vmware.com>

To be compliant with XDG user directory layout,
the user's plugin directory is changed from
~/.traceevent/plugins to ~/.local/lib/traceevent/plugins/
Thanks to Patrick McLean:
https://lore.kernel.org/linux-trace-devel/20190313144206.41e75cf8@patrickm/

The system plugin directory is changed from
(install_prefix)/lib/trace-cmd/plugins to (install_prefix)/lib/traceevent/plugins
This change paves the way for implementing trace-cmd specific plugins.

Suggested-by: Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 Makefile                        | 16 ++++++++--------
 lib/traceevent/event-plugin.c   |  6 +++---
 lib/traceevent/plugins/Makefile |  4 ++--
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/Makefile b/Makefile
index e20eced..cb5b07b 100644
--- a/Makefile
+++ b/Makefile
@@ -56,15 +56,15 @@ export img_install img_install_SQ
 export DESTDIR DESTDIR_SQ
 
 ifeq ($(prefix),$(HOME))
-plugin_dir = $(HOME)/.trace-cmd/plugins
+plugin_traceevent_dir = $(HOME)/.local/lib/traceevent/plugins
 python_dir = $(HOME)/.trace-cmd/python
 var_dir = $(HOME)/.trace-cmd/
 else
-plugin_dir = $(libdir)/trace-cmd/plugins
+plugin_traceevent_dir = $(libdir)/traceevent/plugins
 python_dir ?= $(libdir)/trace-cmd/python
-PLUGIN_DIR = -DPLUGIN_DIR="$(plugin_dir)"
+PLUGIN_DIR_TRACEEVENT = -DPLUGIN_TRACEEVENT_DIR="$(plugin_traceevent_dir)"
 PYTHON_DIR = -DPYTHON_DIR="$(python_dir)"
-PLUGIN_DIR_SQ = '$(subst ','\'',$(PLUGIN_DIR))'
+PLUGIN_DIR_TRACEEVENT_SQ = '$(subst ','\'',$(PLUGIN_DIR_TRACEEVENT))'
 PYTHON_DIR_SQ = '$(subst ','\'',$(PYTHON_DIR))'
 var_dir = /var
 endif
@@ -72,7 +72,7 @@ endif
 # Shell quotes
 bindir_SQ = $(subst ','\'',$(bindir))
 bindir_relative_SQ = $(subst ','\'',$(bindir_relative))
-plugin_dir_SQ = $(subst ','\'',$(plugin_dir))
+plugin_traceevent_dir_SQ = $(subst ','\'',$(plugin_traceevent_dir))
 python_dir_SQ = $(subst ','\'',$(python_dir))
 
 VAR_DIR = -DVAR_DIR="$(var_dir)"
@@ -85,10 +85,10 @@ HELP_DIR_SQ = '$(subst ','\'',$(HELP_DIR))'
 
 BASH_COMPLETE_DIR ?= /etc/bash_completion.d
 
-export PLUGIN_DIR
+export PLUGIN_DIR_TRACEEVENT
 export PYTHON_DIR
 export PYTHON_DIR_SQ
-export plugin_dir_SQ
+export plugin_traceevent_dir_SQ
 export python_dir_SQ
 export var_dir
 
@@ -239,7 +239,7 @@ LIBS += -laudit
 endif
 
 # Append required CFLAGS
-override CFLAGS += $(INCLUDES) $(PLUGIN_DIR_SQ) $(VAR_DIR)
+override CFLAGS += $(INCLUDES) $(PLUGIN_DIR_TRACEEVENT_SQ) $(VAR_DIR)
 override CFLAGS += $(udis86-flags) $(blk-flags)
 override LDFLAGS += $(udis86-ldflags)
 
diff --git a/lib/traceevent/event-plugin.c b/lib/traceevent/event-plugin.c
index 4fc4ee3..88cd5f0 100644
--- a/lib/traceevent/event-plugin.c
+++ b/lib/traceevent/event-plugin.c
@@ -20,7 +20,7 @@
 #include "event-utils.h"
 #include "trace-seq.h"
 
-#define LOCAL_PLUGIN_DIR ".traceevent/plugins"
+#define LOCAL_PLUGIN_DIR ".local/lib/traceevent/plugins/"
 
 static struct registered_plugin_options {
 	struct registered_plugin_options	*next;
@@ -579,9 +579,9 @@ void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
 	 * If a system plugin directory was defined,
 	 * check that first.
 	 */
-#ifdef PLUGIN_DIR
+#ifdef PLUGIN_TRACEEVENT_DIR
 	if (!tep || !(tep->flags & TEP_DISABLE_SYS_PLUGINS))
-		load_plugins_dir(tep, suffix, PLUGIN_DIR,
+		load_plugins_dir(tep, suffix, PLUGIN_TRACEEVENT_DIR,
 				 load_plugin, data);
 #endif
 
diff --git a/lib/traceevent/plugins/Makefile b/lib/traceevent/plugins/Makefile
index 061d919..4050019 100644
--- a/lib/traceevent/plugins/Makefile
+++ b/lib/traceevent/plugins/Makefile
@@ -53,11 +53,11 @@ $(bdir)/plugin_python_loader.so: $(bdir)/%.so: $(bdir)/%.o
 PLUGINS_INSTALL = $(subst .so,.install,$(PLUGINS))
 
 $(PLUGINS_INSTALL): $(bdir)/%.install : $(bdir)/%.so force
-	$(Q)$(call do_install_data,$<,$(plugin_dir_SQ))
+	$(Q)$(call do_install_data,$<,$(plugin_traceevent_dir_SQ))
 
 install_plugins: $(PLUGINS_INSTALL)
 
-# The following targets are necessary to trigger a rebuild when $(PLUGIN_DIR)
+# The following targets are necessary to trigger a rebuild when $(PLUGIN_DIR_TRACEEVENT)
 # and $(PYTHON_DIR) change. Without them, a full clean build would necessary
 # in order to get the binaries updated.
 
-- 
2.21.0

[PATCH v3 5/5] trace-cmd: Add initial infrastructure for trace-cmd specific plugins.

[Tzvetomir Stoyanov (VMware)]

Create a new directory lib/trace-cmd/plugins, where the libtracecmd
plugins will be placed. Plugins compilation is integrated in
the trace-cmd build process. New plugins are installed in
$(HOME)/.local/lib/trace-cmd/plugins or $(libdir)/trace-cmd/plugins directories.
Current python_plugin.so is part of libtraceevent plugins, so the python
plugins path is changed from
$(HOME)/.trace-cmd/python to $(HOME)/.local/lib/traceevent/python
and
$(libdir)/trace-cmd/python to $(libdir)/traceevent/python

Added initial set of APIs for working with trace-cmd plugins

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .gitignore                     |   2 +
 Makefile                       |  45 +++--
 include/trace-cmd/trace-cmd.h  |  44 ++++-
 lib/trace-cmd/Makefile         |   1 +
 lib/trace-cmd/plugins/Makefile |  58 ++++++
 lib/trace-cmd/trace-plugin.c   | 313 +++++++++++++++++++++++++++++++++
 6 files changed, 450 insertions(+), 13 deletions(-)
 create mode 100644 lib/trace-cmd/plugins/Makefile
 create mode 100644 lib/trace-cmd/trace-plugin.c

diff --git a/.gitignore b/.gitignore
index 20bb5a3..5a8800a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,3 +20,5 @@ TAGS
 cscope*
 traceevent_plugin_dir
 trace_python_dir
+tracecmd_plugin_dir
+python_dir
diff --git a/Makefile b/Makefile
index cb5b07b..dd7a84b 100644
--- a/Makefile
+++ b/Makefile
@@ -57,14 +57,18 @@ export DESTDIR DESTDIR_SQ
 
 ifeq ($(prefix),$(HOME))
 plugin_traceevent_dir = $(HOME)/.local/lib/traceevent/plugins
-python_dir = $(HOME)/.trace-cmd/python
+plugin_tracecmd_dir = $(HOME)/.local/lib/trace-cmd/plugins
+python_dir = $(HOME)/.local/lib/traceevent/python
 var_dir = $(HOME)/.trace-cmd/
 else
 plugin_traceevent_dir = $(libdir)/traceevent/plugins
-python_dir ?= $(libdir)/trace-cmd/python
+plugin_tracecmd_dir = $(libdir)/trace-cmd/plugins
+python_dir ?= $(libdir)/traceevent/python
 PLUGIN_DIR_TRACEEVENT = -DPLUGIN_TRACEEVENT_DIR="$(plugin_traceevent_dir)"
+PLUGIN_DIR_TRACECMD = -DPLUGIN_TRACECMD_DIR="$(plugin_tracecmd_dir)"
 PYTHON_DIR = -DPYTHON_DIR="$(python_dir)"
 PLUGIN_DIR_TRACEEVENT_SQ = '$(subst ','\'',$(PLUGIN_DIR_TRACEEVENT))'
+PLUGIN_DIR_TRACECMD_SQ = '$(subst ','\'',$(PLUGIN_DIR_TRACECMD))'
 PYTHON_DIR_SQ = '$(subst ','\'',$(PYTHON_DIR))'
 var_dir = /var
 endif
@@ -73,6 +77,7 @@ endif
 bindir_SQ = $(subst ','\'',$(bindir))
 bindir_relative_SQ = $(subst ','\'',$(bindir_relative))
 plugin_traceevent_dir_SQ = $(subst ','\'',$(plugin_traceevent_dir))
+plugin_tracecmd_dir_SQ = $(subst ','\'',$(plugin_tracecmd_dir))
 python_dir_SQ = $(subst ','\'',$(python_dir))
 
 VAR_DIR = -DVAR_DIR="$(var_dir)"
@@ -86,9 +91,11 @@ HELP_DIR_SQ = '$(subst ','\'',$(HELP_DIR))'
 BASH_COMPLETE_DIR ?= /etc/bash_completion.d
 
 export PLUGIN_DIR_TRACEEVENT
+export PLUGIN_DIR_TRACECMD
 export PYTHON_DIR
 export PYTHON_DIR_SQ
 export plugin_traceevent_dir_SQ
+export plugin_tracecmd_dir_SQ
 export python_dir_SQ
 export var_dir
 
@@ -239,7 +246,8 @@ LIBS += -laudit
 endif
 
 # Append required CFLAGS
-override CFLAGS += $(INCLUDES) $(PLUGIN_DIR_TRACEEVENT_SQ) $(VAR_DIR)
+override CFLAGS += $(INCLUDES) $(VAR_DIR)
+override CFLAGS += $(PLUGIN_DIR_TRACEEVENT_SQ) $(PLUGIN_DIR_TRACECMD_SQ)
 override CFLAGS += $(udis86-flags) $(blk-flags)
 override LDFLAGS += $(udis86-ldflags)
 
@@ -268,13 +276,16 @@ gui: force $(CMD_TARGETS) $(kshark-dir)/build/Makefile
 	@echo "gui build complete"
 	@echo "  kernelshark located at $(kshark-dir)/bin"
 
-trace-cmd: force $(LIBTRACEEVENT_STATIC) $(LIBTRACECMD_STATIC)
+trace-cmd: force $(LIBTRACEEVENT_STATIC) $(LIBTRACECMD_STATIC) \
+	force $(obj)/lib/trace-cmd/plugins/tracecmd_plugin_dir
 	$(Q)$(MAKE) -C $(src)/tracecmd $(obj)/tracecmd/$@
 
-$(LIBTRACEEVENT_SHARED): force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
+$(LIBTRACEEVENT_SHARED): force $(obj)/lib/traceevent/plugins/python_dir \
+			 $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
 	$(Q)$(MAKE) -C $(src)/lib/traceevent $@
 
-$(LIBTRACEEVENT_STATIC): force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
+$(LIBTRACEEVENT_STATIC): force $(obj)/lib/traceevent/plugins/python_dir \
+			 $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
 	$(Q)$(MAKE) -C $(src)/lib/traceevent $@
 
 $(LIBTRACECMD_STATIC): force
@@ -290,13 +301,22 @@ libtracecmd.so: $(LIBTRACECMD_SHARED)
 
 libs: $(LIBTRACECMD_SHARED) $(LIBTRACEEVENT_SHARED)
 
-plugins: force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir $(obj)/lib/traceevent/plugins/trace_python_dir
+plugins_traceevent: force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir \
+		   $(obj)/lib/traceevent/plugins/python_dir
 	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins
 
+plugins_tracecmd: force $(obj)/lib/trace-cmd/plugins/tracecmd_plugin_dir
+	$(Q)$(MAKE) -C $(src)/lib/trace-cmd/plugins
+
+plugins: plugins_traceevent plugins_tracecmd
+
 $(obj)/lib/traceevent/plugins/traceevent_plugin_dir: force
 	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $@
 
-$(obj)/lib/traceevent/plugins/trace_python_dir: force
+$(obj)/lib/trace-cmd/plugins/tracecmd_plugin_dir: force
+	$(Q)$(MAKE) -C $(src)/lib/trace-cmd/plugins $@
+
+$(obj)/lib/traceevent/plugins/python_dir: force
 	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $@
 
 show_gui_make:
@@ -322,8 +342,12 @@ cscope: force
 	$(RM) cscope*
 	$(call find_tag_files) | cscope -b -q
 
-install_plugins: force
-	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins $@
+install_plugins_traceevent: force
+	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins install_plugins
+install_plugins_tracecmd: force
+	$(Q)$(MAKE) -C $(src)/lib/trace-cmd/plugins install_plugins
+
+install_plugins: install_plugins_traceevent install_plugins_tracecmd
 
 install_python: force
 	$(Q)$(MAKE) -C $(src)/python $@
@@ -371,6 +395,7 @@ clean:
 	$(MAKE) -C $(src)/lib/traceevent clean
 	$(MAKE) -C $(src)/lib/trace-cmd clean
 	$(MAKE) -C $(src)/lib/traceevent/plugins clean
+	$(MAKE) -C $(src)/lib/trace-cmd/plugins clean
 	$(MAKE) -C $(src)/python clean
 	$(MAKE) -C $(src)/tracecmd clean
 	if [ -f $(kshark-dir)/build/Makefile ]; then $(MAKE) -C $(kshark-dir)/build clean; fi
diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h
index 092bd89..6a182af 100644
--- a/include/trace-cmd/trace-cmd.h
+++ b/include/trace-cmd/trace-cmd.h
@@ -22,9 +22,6 @@ void tracecmd_parse_trace_clock(struct tep_handle *pevent, char *file, int size)
 void tracecmd_parse_proc_kallsyms(struct tep_handle *pevent, char *file, unsigned int size);
 void tracecmd_parse_ftrace_printk(struct tep_handle *pevent, char *file, unsigned int size);
 
-extern int tracecmd_disable_sys_plugins;
-extern int tracecmd_disable_plugins;
-
 char **tracecmd_event_systems(const char *tracing_dir);
 char **tracecmd_system_events(const char *tracing_dir, const char *system);
 struct tep_handle *tracecmd_local_events(const char *tracing_dir);
@@ -53,6 +50,47 @@ struct tracecmd_output;
 struct tracecmd_recorder;
 struct hook_list;
 
+/* --- tracecmd plugins --- */
+
+extern int tracecmd_disable_sys_plugins;
+extern int tracecmd_disable_plugins;
+
+enum tracecmd_context {
+	TRACECMD_INPUT,
+	TRACECMD_OUTPUT,
+};
+
+enum tracecmd_plugin_flag {
+	TRACECMD_DISABLE_SYS_PLUGINS	= 1,
+	TRACECMD_DISABLE_PLUGINS	= 1 << 1,
+
+};
+
+struct trace_plugin_context;
+
+struct trace_plugin_context *
+tracecmd_plugin_context_create(enum tracecmd_context context, void *data);
+
+void tracecmd_plugin_set_flag(struct trace_plugin_context *context,
+			      enum tracecmd_plugin_flag flag);
+
+#define TRACECMD_PLUGIN_LOADER tracecmd_plugin_loader
+#define TRACECMD_PLUGIN_UNLOADER tracecmd_plugin_unloader
+#define TRACECMD_PLUGIN_ALIAS tracecmd_plugin_alias
+#define _MAKE_STR(x)	#x
+#define MAKE_STR(x)	_MAKE_STR(x)
+#define TRACECMD_PLUGIN_LOADER_NAME MAKE_STR(TRACECMD_PLUGIN_LOADER)
+#define TRACECMD_PLUGIN_UNLOADER_NAME MAKE_STR(TRACECMD_PLUGIN_UNLOADER)
+#define TRACECMD_PLUGIN_ALIAS_NAME MAKE_STR(TRACECMD_PLUGIN_ALIAS)
+
+typedef int (*tracecmd_plugin_load_func)(struct trace_plugin_context *trace);
+typedef int (*tracecmd_plugin_unload_func)(struct trace_plugin_context *trace);
+
+struct tracecmd_input *
+tracecmd_plugin_context_input(struct trace_plugin_context *trace_context);
+struct tracecmd_output *
+tracecmd_plugin_context_output(struct trace_plugin_context *trace_context);
+
 static inline int tracecmd_host_bigendian(void)
 {
 	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4 };
diff --git a/lib/trace-cmd/Makefile b/lib/trace-cmd/Makefile
index 3b4b5aa..6f3e6b1 100644
--- a/lib/trace-cmd/Makefile
+++ b/lib/trace-cmd/Makefile
@@ -15,6 +15,7 @@ OBJS += trace-recorder.o
 OBJS += trace-util.o
 OBJS += trace-filter-hash.o
 OBJS += trace-msg.o
+OBJS += trace-plugin.o
 
 # Additional util objects
 OBJS += trace-blk-hack.o
diff --git a/lib/trace-cmd/plugins/Makefile b/lib/trace-cmd/plugins/Makefile
new file mode 100644
index 0000000..240e6be
--- /dev/null
+++ b/lib/trace-cmd/plugins/Makefile
@@ -0,0 +1,58 @@
+include $(src)/scripts/utils.mk
+
+bdir:=$(obj)/lib/trace-cmd/plugins
+
+PLUGIN_OBJS =
+
+PLUGIN_OBJS := $(PLUGIN_OBJS:%.o=$(bdir)/%.o)
+PLUGIN_BUILD := $(PLUGIN_OBJS:$(bdir)/%.o=$(bdir)/%.so)
+
+PLUGINS := $(PLUGIN_BUILD)
+
+DEPS := $(PLUGIN_OBJS:$(bdir)/%.o=$(bdir)/.%.d)
+
+all: $(PLUGINS)
+
+$(bdir):
+	@mkdir -p $(bdir)
+
+$(PLUGIN_OBJS): | $(bdir)
+$(DEPS): | $(bdir)
+
+$(PLUGIN_OBJS): $(bdir)/%.o : %.c
+	$(Q)$(do_compile_plugin_obj)
+
+$(PLUGIN_BUILD): $(bdir)/%.so: $(bdir)/%.o
+	$(Q)$(do_plugin_build)
+
+$(DEPS): $(bdir)/.%.d: %.c
+	$(Q)$(CC) -M $(CPPFLAGS) $(CFLAGS) $< > $@
+
+$(PLUGIN_OBJS): $(bdir)/%.o : $(bdir)/.%.d
+
+PLUGINS_INSTALL = $(subst .so,.install,$(PLUGINS))
+
+$(PLUGINS_INSTALL): $(bdir)/%.install : $(bdir)/%.so force
+	$(Q)$(call do_install_data,$<,$(plugin_tracecmd_dir_SQ))
+
+install_plugins: $(PLUGINS_INSTALL)
+
+# The following targets are necessary to trigger a rebuild when
+# $(PLUGIN_DIR_TRACECMD) change. Without them, a full clean build would
+# necessary in order to get the binaries updated.
+
+$(bdir)/tracecmd_plugin_dir: $(bdir) force
+	$(Q)$(N)$(call update_dir, 'PLUGIN_DIR_TRACECMD=$(PLUGIN_DIR_TRACECMD)')
+
+dep_includes := $(wildcard $(DEPS))
+
+ifneq ($(dep_includes),)
+  include $(dep_includes)
+endif
+
+clean:
+	$(RM) -f $(bdir)/*.a $(bdir)/*.so $(bdir)/*.o $(bdir)/.*.d\
+		$(bdir)/tracecmd_plugin_dir
+
+force:
+.PHONY: clean force
diff --git a/lib/trace-cmd/trace-plugin.c b/lib/trace-cmd/trace-plugin.c
new file mode 100644
index 0000000..6bec18b
--- /dev/null
+++ b/lib/trace-cmd/trace-plugin.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <stdlib.h>
+#include <unistd.h>
+#include <dlfcn.h>
+#include <sys/stat.h>
+#include <libgen.h>
+#include "trace-cmd.h"
+#include "trace-local.h"
+
+#define LOCAL_PLUGIN_DIR ".local/lib/trace-cmd/plugins/"
+
+struct trace_plugin_list {
+	struct trace_plugin_list	*next;
+	char				*name;
+	void				*handle;
+};
+
+struct trace_plugin_context {
+	enum tracecmd_context context;
+	enum tracecmd_plugin_flag flags;
+	union {
+		void				*data;
+		struct tracecmd_input		*trace_input;
+		struct tracecmd_output		*trace_output;
+	};
+};
+
+/**
+ * tracecmd_plugin_context_create - Create and initialize tracecmd plugins context.
+ * @context: Context of the trace-cmd command.
+ * @data: Pointer to the context specific data, which will be passed to plugins.
+ *
+ * Returns a pointer to created tracecmd plugins context, or NULL in case memory
+ * allocation fails. The returned pointer should be freed by free ().
+ */
+struct trace_plugin_context *
+tracecmd_plugin_context_create(enum tracecmd_context context, void *data)
+{
+	struct trace_plugin_context *trace;
+
+	trace = calloc(1, sizeof(struct trace_plugin_context));
+	if (!trace)
+		return NULL;
+	trace->context = context;
+	trace->data = data;
+	return trace;
+}
+
+/**
+ * tracecmd_plugin_set_flag - Set a flag to tracecmd plugins context.
+ * @context: Context of the trace-cmd command.
+ * @flag: Flag, whil will be set.
+ *
+ */
+void tracecmd_plugin_set_flag(struct trace_plugin_context *context,
+			      enum tracecmd_plugin_flag flag)
+{
+	if (context)
+		context->flags |= flag;
+}
+
+/**
+ * tracecmd_plugin_context_input - Get a tracecmd_input plugin context.
+ * @context: Context of the trace-cmd command.
+ *
+ * Returns pointer to tracecmd_input, if such context is available or
+ * NULL otherwise.
+ */
+struct tracecmd_input *
+tracecmd_plugin_context_input(struct trace_plugin_context *context)
+{
+	if (!context || context->context != TRACECMD_INPUT)
+		return NULL;
+	return context->trace_input;
+}
+
+/**
+ * tracecmd_plugin_context_output - Get a tracecmd_output plugin context
+ * @context: Context of the trace-cmd command.
+ *
+ * Returns pointer to tracecmd_output, if such context is available or
+ * NULL otherwise.
+ */
+struct tracecmd_output *
+tracecmd_plugin_context_output(struct trace_plugin_context *context)
+{
+	if (!context || context->context != TRACECMD_OUTPUT)
+		return NULL;
+	return context->trace_output;
+}
+
+static void
+load_plugin(struct trace_plugin_context *trace, const char *path,
+	    const char *file, void *data)
+{
+	struct trace_plugin_list **plugin_list = data;
+	tracecmd_plugin_load_func func;
+	struct trace_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, TRACECMD_PLUGIN_ALIAS_NAME);
+	if (!alias)
+		alias = file;
+
+	func = dlsym(handle, TRACECMD_PLUGIN_LOADER_NAME);
+	if (!func) {
+		warning("could not find func '%s' in plugin '%s'\n%s\n",
+			TRACECMD_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(trace);
+	return;
+
+ out_free:
+	free(plugin);
+}
+
+static void
+load_plugins_dir(struct trace_plugin_context *trace, const char *suffix,
+		 const char *path,
+		 void (*load_plugin)(struct trace_plugin_context *trace,
+				     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(trace, path, name, data);
+	}
+
+	closedir(dir);
+}
+
+static char *get_source_plugins_dir(void)
+{
+	char *p, path[PATH_MAX+1];
+	int ret;
+
+	ret = readlink("/proc/self/exe", path, PATH_MAX);
+	if (ret > PATH_MAX || ret < 0)
+		return NULL;
+
+	dirname(path);
+	p = strrchr(path, '/');
+	if (!p)
+		return NULL;
+	/* Check if we are in the the source tree */
+	if (strcmp(p, "/tracecmd") != 0)
+		return NULL;
+
+	strcpy(p, "/lib/trace-cmd/plugins");
+	return strdup(path);
+}
+
+static void
+load_plugins_hook(struct trace_plugin_context *trace, const char *suffix,
+		  void (*load_plugin)(struct trace_plugin_context *trace,
+				      const char *path,
+				      const char *name,
+				      void *data),
+		  void *data)
+{
+	char *home;
+	char *path;
+	char *envdir;
+	int ret;
+
+	if (trace && trace->flags & TRACECMD_DISABLE_PLUGINS)
+		return;
+
+	/*
+	 * If a system plugin directory was defined,
+	 * check that first.
+	 */
+#ifdef PLUGIN_TRACECMD_DIR
+	if (!trace || !(trace->flags & TRACECMD_DISABLE_SYS_PLUGINS))
+		load_plugins_dir(trace, suffix, PLUGIN_TRACECMD_DIR,
+				 load_plugin, data);
+#endif
+
+	/*
+	 * Next let the environment-set plugin directory
+	 * override the system defaults.
+	 */
+	envdir = getenv("TRACECMD_PLUGIN_DIR");
+	if (envdir)
+		load_plugins_dir(trace, 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(trace, suffix, path, load_plugin, data);
+
+	free(path);
+
+	path = get_source_plugins_dir();
+	if (path) {
+		load_plugins_dir(trace, suffix, path, load_plugin, data);
+		free(path);
+	}
+}
+
+/**
+ * tracecmd_load_plugins - Load trace-cmd specific plugins.
+ * @context: Context of the trace-cmd command, will be passed to the plugins
+ *	     at load time.
+ *
+ * Returns a list of loaded plugins
+ */
+struct trace_plugin_list*
+tracecmd_load_plugins(struct trace_plugin_context *trace)
+{
+	struct trace_plugin_list *list = NULL;
+
+	load_plugins_hook(trace, ".so", load_plugin, &list);
+	return list;
+}
+
+/**
+ * tracecmd_unload_plugins - Unload trace-cmd specific plugins.
+ * @plugin_list - List of plugins, previously loaded with tracecmd_load_plugins.
+ * @context: Context of the trace-cmd command, will be passed to the plugins
+ *	     at unload time.
+ *
+ */
+void
+tracecmd_unload_plugins(struct trace_plugin_list *plugin_list,
+			struct trace_plugin_context *trace)
+{
+	tracecmd_plugin_unload_func func;
+	struct trace_plugin_list *list;
+
+	while (plugin_list) {
+		list = plugin_list;
+		plugin_list = list->next;
+		func = dlsym(list->handle, TRACECMD_PLUGIN_UNLOADER_NAME);
+		if (func)
+			func(trace);
+		dlclose(list->handle);
+		free(list->name);
+		free(list);
+	}
+}
-- 
2.21.0

Re: [PATCH v3 3/5] trace-cmd: Load libtraceevent plugins from build folder, if exists.

[Steven Rostedt]

On Wed,  2 Oct 2019 14:41:50 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

> When a development version of trace-cmd is built and run on the machine,
> by default it loads only installed plugins, from system drierctories.
> Thus, the development plugins will not be loaded. To simplify the development
> process, a new logic is added:
>   At plugins load time, check the location of trace-cmd application and look
>   for "plugins" directory around it. If found, load plugins from it. Those
>   pluigins will be loaded last, so in case of duplication the "development"
>   plugins win.
> 
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> ---
>  lib/traceevent/event-plugin.c | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/lib/traceevent/event-plugin.c b/lib/traceevent/event-plugin.c
> index bc10205..4fc4ee3 100644
> --- a/lib/traceevent/event-plugin.c
> +++ b/lib/traceevent/event-plugin.c
> @@ -14,6 +14,7 @@
>  #include <unistd.h>
>  #include <dirent.h>
>  #include <errno.h>
> +#include <libgen.h>
>  #include "event-parse.h"
>  #include "event-parse-local.h"
>  #include "event-utils.h"
> @@ -538,6 +539,27 @@ load_plugins_dir(struct tep_handle *tep, const char *suffix,
>  	closedir(dir);
>  }
>  
> +static char *get_source_plugins_dir(void)
> +{
> +	char *p, path[PATH_MAX+1];
> +	int ret;
> +
> +	ret = readlink("/proc/self/exe", path, PATH_MAX);
> +	if (ret > PATH_MAX || ret < 0)
> +		return NULL;
> +
> +	dirname(path);
> +	p = strrchr(path, '/');
> +	if (!p)
> +		return NULL;
> +	/* Check if we are in the the source tree */
> +	if (strcmp(p, "/tracecmd") != 0)

Hmm, this is in the lib/libtraceevent directory. We shouldn't be
referencing trace-cmd code here. We should have a way to override the
plugins from the trace-cmd side, perhaps after tep_load_plugins_hook()
gets called?

-- Steve


> +		return NULL;
> +
> +	strcpy(p, "/lib/traceevent/plugins");
> +	return strdup(path);
> +}
> +
>  void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
>  			   void (*load_plugin)(struct tep_handle *tep,
>  					       const char *path,
> @@ -588,6 +610,12 @@ void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
>  	load_plugins_dir(tep, suffix, path, load_plugin, data);
>  
>  	free(path);
> +
> +	path = get_source_plugins_dir();
> +	if (path) {
> +		load_plugins_dir(tep, suffix, path, load_plugin, data);
> +		free(path);
> +	}
>  }
>  
>  struct tep_plugin_list*

Re: [PATCH v3 3/5] trace-cmd: Load libtraceevent plugins from build folder, if exists.

[Steven Rostedt]

On Wed,  2 Oct 2019 14:41:50 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

Also there's a few typos (which I originally fixed before seeing the
issue of trace-cmd code in libtraceevent).

> When a development version of trace-cmd is built and run on the machine,
> by default it loads only installed plugins, from system drierctories.

 "directories"

> Thus, the development plugins will not be loaded. To simplify the development
> process, a new logic is added:
>   At plugins load time, check the location of trace-cmd application and look
>   for "plugins" directory around it. If found, load plugins from it. Those
>   pluigins will be loaded last, so in case of duplication the "development"

 "plugins"

>   plugins win.
> 
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
>

-- Steve

Re: [PATCH v3 5/5] trace-cmd: Add initial infrastructure for trace-cmd specific plugins.

[Steven Rostedt]

On Wed,  2 Oct 2019 14:41:52 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:

>  
> -$(LIBTRACEEVENT_SHARED): force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
> +$(LIBTRACEEVENT_SHARED): force $(obj)/lib/traceevent/plugins/python_dir \
> +			 $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
>  	$(Q)$(MAKE) -C $(src)/lib/traceevent $@
>  
> -$(LIBTRACEEVENT_STATIC): force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
> +$(LIBTRACEEVENT_STATIC): force $(obj)/lib/traceevent/plugins/python_dir \
> +			 $(obj)/lib/traceevent/plugins/traceevent_plugin_dir
>  	$(Q)$(MAKE) -C $(src)/lib/traceevent $@
>  
>  $(LIBTRACECMD_STATIC): force
> @@ -290,13 +301,22 @@ libtracecmd.so: $(LIBTRACECMD_SHARED)
>  
>  libs: $(LIBTRACECMD_SHARED) $(LIBTRACEEVENT_SHARED)
>  
> -plugins: force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir $(obj)/lib/traceevent/plugins/trace_python_dir
> +plugins_traceevent: force $(obj)/lib/traceevent/plugins/traceevent_plugin_dir \
> +		   $(obj)/lib/traceevent/plugins/python_dir
>  	$(Q)$(MAKE) -C $(src)/lib/traceevent/plugins
>  

Hmm, I'm getting this:

$ make
make[1]: *** No rule to make target '/work/git/trace-cmd.git/lib/traceevent/plugins/python_dir'.  Stop.
make: *** [Makefile:320: /work/git/trace-cmd.git/lib/traceevent/plugins/python_dir] Error 2

It works if I manually create the missing python_dir.

-- Steve

Re: [PATCH v3 3/5] trace-cmd: Load libtraceevent plugins from build folder, if exists.

[Tzvetomir Stoyanov]

On Thu, Oct 3, 2019 at 2:49 AM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Wed,  2 Oct 2019 14:41:50 +0300
> "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
>
> > When a development version of trace-cmd is built and run on the machine,
> > by default it loads only installed plugins, from system drierctories.
> > Thus, the development plugins will not be loaded. To simplify the development
> > process, a new logic is added:
> >   At plugins load time, check the location of trace-cmd application and look
> >   for "plugins" directory around it. If found, load plugins from it. Those
> >   pluigins will be loaded last, so in case of duplication the "development"
> >   plugins win.
> >
> > Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
> > ---
> >  lib/traceevent/event-plugin.c | 28 ++++++++++++++++++++++++++++
> >  1 file changed, 28 insertions(+)
> >
> > diff --git a/lib/traceevent/event-plugin.c b/lib/traceevent/event-plugin.c
> > index bc10205..4fc4ee3 100644
> > --- a/lib/traceevent/event-plugin.c
> > +++ b/lib/traceevent/event-plugin.c
> > @@ -14,6 +14,7 @@
> >  #include <unistd.h>
> >  #include <dirent.h>
> >  #include <errno.h>
> > +#include <libgen.h>
> >  #include "event-parse.h"
> >  #include "event-parse-local.h"
> >  #include "event-utils.h"
> > @@ -538,6 +539,27 @@ load_plugins_dir(struct tep_handle *tep, const char *suffix,
> >       closedir(dir);
> >  }
> >
> > +static char *get_source_plugins_dir(void)
> > +{
> > +     char *p, path[PATH_MAX+1];
> > +     int ret;
> > +
> > +     ret = readlink("/proc/self/exe", path, PATH_MAX);
> > +     if (ret > PATH_MAX || ret < 0)
> > +             return NULL;
> > +
> > +     dirname(path);
> > +     p = strrchr(path, '/');
> > +     if (!p)
> > +             return NULL;
> > +     /* Check if we are in the the source tree */
> > +     if (strcmp(p, "/tracecmd") != 0)
>
> Hmm, this is in the lib/libtraceevent directory. We shouldn't be
> referencing trace-cmd code here. We should have a way to override the
> plugins from the trace-cmd side, perhaps after tep_load_plugins_hook()
> gets called?
>

I agree, we should move this check outside of the library.
I'll expose the functionality of load_plugins_dir() as a library API.
Thanks !

> -- Steve
>
>
> > +             return NULL;
> > +
> > +     strcpy(p, "/lib/traceevent/plugins");
> > +     return strdup(path);
> > +}
> > +
> >  void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
> >                          void (*load_plugin)(struct tep_handle *tep,
> >                                              const char *path,
> > @@ -588,6 +610,12 @@ void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
> >       load_plugins_dir(tep, suffix, path, load_plugin, data);
> >
> >       free(path);
> > +
> > +     path = get_source_plugins_dir();
> > +     if (path) {
> > +             load_plugins_dir(tep, suffix, path, load_plugin, data);
> > +             free(path);
> > +     }
> >  }
> >
> >  struct tep_plugin_list*
>


-- 
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center