From e3d09ec8126fe2c9a3ade661e2126e215ca27a80 Mon Sep 17 00:00:00 2001 From: He Kuang Date: Thu, 28 May 2015 13:28:54 +0000 Subject: tools lib traceevent: Export dynamic symbols used by traceevent plugins Traceevent plugins need dynamic symbols exported from libtraceevent.a, otherwise a dlopen error will occur during plugins loading. This patch uses dynamic-list-file to export dynamic symbols which will be used in plugins to perf executable. The problem is covered up if feature-libpython is enabled, because PYTHON_EMBED_LDOPTS contains '-Xlinker --export-dynamic' which adds all symbols to the dynamic symbol table. So we should reproduce the problem by setting NO_LIBPYTHON=1. Before this patch: (Prepare plugins) $ ls /root/.traceevent/plugins/ plugin_sched_switch.so plugin_function.so ... $ perf record -e 'ftrace:function' ls $ perf script Warning: could not load plugin '/mnt/data/root/.traceevent/plugins/plugin_sched_switch.so' /root/.traceevent/plugins/plugin_sched_switch.so: undefined symbol: pevent_unregister_event_handler Warning: could not load plugin '/root/.traceevent/plugins/plugin_function.so' /root/.traceevent/plugins/plugin_function.so: undefined symbol: warning ... :1049 1049 [000] 9666.754487: ftrace:function: ffffffff8118bc50 <-- ffffffff8118c5b3 :1049 1049 [000] 9666.754487: ftrace:function: ffffffff818e2440 <-- ffffffff8118bc75 :1049 1049 [000] 9666.754487: ftrace:function: ffffffff8106eee0 <-- ffffffff811212e2 After this patch: $ perf record -e 'ftrace:function' ls $ perf script :1049 1049 [000] 9666.754487: ftrace:function: __set_task_comm :1049 1049 [000] 9666.754487: ftrace:function: _raw_spin_lock :1049 1049 [000] 9666.754487: ftrace:function: task_tgid_nr_ns ... Signed-off-by: He Kuang Acked-by: Jiri Olsa Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1432819735-35040-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/traceevent/Makefile | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'tools/lib/traceevent') diff --git a/tools/lib/traceevent/Makefile b/tools/lib/traceevent/Makefile index 84640394ebf9..6daaff652aff 100644 --- a/tools/lib/traceevent/Makefile +++ b/tools/lib/traceevent/Makefile @@ -23,6 +23,7 @@ endef # Allow setting CC and AR, or setting CROSS_COMPILE as a prefix. $(call allow-override,CC,$(CROSS_COMPILE)gcc) $(call allow-override,AR,$(CROSS_COMPILE)ar) +$(call allow-override,NM,$(CROSS_COMPILE)nm) EXT = -std=gnu99 INSTALL = install @@ -157,8 +158,9 @@ PLUGINS_IN := $(PLUGINS:.so=-in.o) TE_IN := $(OUTPUT)libtraceevent-in.o LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) +DYNAMIC_LIST_FILE := $(OUTPUT)libtraceevent-dynamic-list -CMD_TARGETS = $(LIB_FILE) $(PLUGINS) +CMD_TARGETS = $(LIB_FILE) $(PLUGINS) $(DYNAMIC_LIST_FILE) TARGETS = $(CMD_TARGETS) @@ -175,6 +177,9 @@ $(OUTPUT)libtraceevent.so: $(TE_IN) $(OUTPUT)libtraceevent.a: $(TE_IN) $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ +$(OUTPUT)libtraceevent-dynamic-list: $(PLUGINS) + $(QUIET_GEN)$(call do_generate_dynamic_list_file, $(PLUGINS), $@) + plugins: $(PLUGINS) __plugin_obj = $(notdir $@) @@ -244,6 +249,13 @@ define do_install_plugins done endef +define do_generate_dynamic_list_file + (echo '{'; \ + $(NM) -u -D $1 | awk 'NF>1 {print "\t"$$2";"}' | sort -u; \ + echo '};'; \ + ) > $2 +endef + install_lib: all_cmd install_plugins $(call QUIET_INSTALL, $(LIB_FILE)) \ $(call do_install,$(LIB_FILE),$(libdir_SQ)) -- cgit