From 3673b8e4ce7237160fa31ee8d7e94a4d5a9976a1 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 25 Mar 2015 15:44:21 -0400 Subject: [PATCH] tracing: Allow for modules to convert their enums to values Update the infrastructure such that modules that declare TRACE_DEFINE_ENUM() will have those enums converted into their values in the tracepoint print fmt strings. Link: http://lkml.kernel.org/r/87vbhjp74q.fsf@rustcorp.com.au Acked-by: Rusty Russell Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- include/linux/module.h | 2 ++ kernel/module.c | 3 +++ kernel/trace/trace.c | 49 ++++++++++++++++++++++++++++++++++--- kernel/trace/trace_events.c | 2 +- 4 files changed, 51 insertions(+), 5 deletions(-) diff --git a/include/linux/module.h b/include/linux/module.h index 42999fe2dbd0..53dc41dd5c62 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -338,6 +338,8 @@ struct module { #ifdef CONFIG_EVENT_TRACING struct ftrace_event_call **trace_events; unsigned int num_trace_events; + struct trace_enum_map **trace_enums; + unsigned int num_trace_enums; #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD unsigned int num_ftrace_callsites; diff --git a/kernel/module.c b/kernel/module.c index b3d634ed06c9..d8f8ab271c2b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2753,6 +2753,9 @@ static int find_module_sections(struct module *mod, struct load_info *info) mod->trace_events = section_objs(info, "_ftrace_events", sizeof(*mod->trace_events), &mod->num_trace_events); + mod->trace_enums = section_objs(info, "_ftrace_enum_map", + sizeof(*mod->trace_enums), + &mod->num_trace_enums); #endif #ifdef CONFIG_TRACING mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ebf49649534c..28e6654e640d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3908,11 +3908,9 @@ static const struct file_operations tracing_saved_cmdlines_size_fops = { .write = tracing_saved_cmdlines_size_write, }; -static void -trace_insert_enum_map(struct trace_enum_map **start, struct trace_enum_map **stop) +static void trace_insert_enum_map(struct trace_enum_map **start, int len) { struct trace_enum_map **map; - int len = stop - start; if (len <= 0) return; @@ -6561,9 +6559,48 @@ extern struct trace_enum_map *__stop_ftrace_enum_maps[]; static void __init trace_enum_init(void) { - trace_insert_enum_map(__start_ftrace_enum_maps, __stop_ftrace_enum_maps); + int len; + + len = __stop_ftrace_enum_maps - __start_ftrace_enum_maps; + trace_insert_enum_map(__start_ftrace_enum_maps, len); +} + +#ifdef CONFIG_MODULES +static void trace_module_add_enums(struct module *mod) +{ + if (!mod->num_trace_enums) + return; + + /* + * Modules with bad taint do not have events created, do + * not bother with enums either. + */ + if (trace_module_has_bad_taint(mod)) + return; + + trace_insert_enum_map(mod->trace_enums, mod->num_trace_enums); +} + +static int trace_module_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + struct module *mod = data; + + switch (val) { + case MODULE_STATE_COMING: + trace_module_add_enums(mod); + break; + } + + return 0; } +static struct notifier_block trace_module_nb = { + .notifier_call = trace_module_notify, + .priority = 0, +}; +#endif + static __init int tracer_init_debugfs(void) { struct dentry *d_tracer; @@ -6590,6 +6627,10 @@ static __init int tracer_init_debugfs(void) trace_enum_init(); +#ifdef CONFIG_MODULES + register_module_notifier(&trace_module_nb); +#endif + #ifdef CONFIG_DYNAMIC_FTRACE trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, &ftrace_update_tot_cnt, &tracing_dyn_info_fops); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index fc58c50fbf01..a576bbe75577 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2034,7 +2034,7 @@ static int trace_module_notify(struct notifier_block *self, static struct notifier_block trace_module_nb = { .notifier_call = trace_module_notify, - .priority = 0, + .priority = 1, /* higher than trace.c module notify */ }; #endif /* CONFIG_MODULES */ -- 2.34.1