From 5487b6ce267bbafd399f3642062d974832d3eddc Mon Sep 17 00:00:00 2001 From: Daniel Bristot de Oliveira Date: Wed, 2 Mar 2022 20:01:34 +0100 Subject: [PATCH] rtla/trace: Add trace event filter helpers Add a set of helper functions to allow rtla tools to filter events in the trace instance. Link: https://lkml.kernel.org/r/12623b1684684549d53b90f4bf66fae44584fd14.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira Cc: Clark Williams Cc: Juri Lelli Cc: Jonathan Corbet Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google) --- tools/tracing/rtla/src/trace.c | 83 ++++++++++++++++++++++++++++++++++ tools/tracing/rtla/src/trace.h | 3 ++ 2 files changed, 86 insertions(+) diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c index 7f8661b2724d..ef44bab0c404 100644 --- a/tools/tracing/rtla/src/trace.c +++ b/tools/tracing/rtla/src/trace.c @@ -204,6 +204,8 @@ static void trace_events_free(struct trace_events *events) tevent = tevent->next; + if (free_event->filter) + free(free_event->filter); if (free_event->trigger) free(free_event->trigger); free(free_event->system); @@ -237,6 +239,21 @@ struct trace_events *trace_event_alloc(const char *event_string) return tevent; } +/* + * trace_event_add_filter - record an event filter + */ +int trace_event_add_filter(struct trace_events *event, char *filter) +{ + if (event->filter) + free(event->filter); + + event->filter = strdup(filter); + if (!event->filter) + return 1; + + return 0; +} + /* * trace_event_add_trigger - record an event trigger action */ @@ -252,6 +269,33 @@ int trace_event_add_trigger(struct trace_events *event, char *trigger) return 0; } +/* + * trace_event_disable_filter - disable an event filter + */ +static void trace_event_disable_filter(struct trace_instance *instance, + struct trace_events *tevent) +{ + char filter[1024]; + int retval; + + if (!tevent->filter) + return; + + if (!tevent->filter_enabled) + return; + + debug_msg("Disabling %s:%s filter %s\n", tevent->system, + tevent->event ? : "*", tevent->filter); + + snprintf(filter, 1024, "!%s\n", tevent->filter); + + retval = tracefs_event_file_write(instance->inst, tevent->system, + tevent->event, "filter", filter); + if (retval < 0) + err_msg("Error disabling %s:%s filter %s\n", tevent->system, + tevent->event ? : "*", tevent->filter); +} + /* * trace_event_disable_trigger - disable an event trigger */ @@ -293,6 +337,7 @@ void trace_events_disable(struct trace_instance *instance, while (tevent) { debug_msg("Disabling event %s:%s\n", tevent->system, tevent->event ? : "*"); if (tevent->enabled) { + trace_event_disable_filter(instance, tevent); trace_event_disable_trigger(instance, tevent); tracefs_event_disable(instance->inst, tevent->system, tevent->event); } @@ -302,6 +347,41 @@ void trace_events_disable(struct trace_instance *instance, } } +/* + * trace_event_enable_filter - enable an event filter associated with an event + */ +static int trace_event_enable_filter(struct trace_instance *instance, + struct trace_events *tevent) +{ + char filter[1024]; + int retval; + + if (!tevent->filter) + return 0; + + if (!tevent->event) { + err_msg("Filter %s applies only for single events, not for all %s:* events\n", + tevent->filter, tevent->system); + return 1; + } + + snprintf(filter, 1024, "%s\n", tevent->filter); + + debug_msg("Enabling %s:%s filter %s\n", tevent->system, + tevent->event ? : "*", tevent->filter); + + retval = tracefs_event_file_write(instance->inst, tevent->system, + tevent->event, "filter", filter); + if (retval < 0) { + err_msg("Error enabling %s:%s filter %s\n", tevent->system, + tevent->event ? : "*", tevent->filter); + return 1; + } + + tevent->filter_enabled = 1; + return 0; +} + /* * trace_event_enable_trigger - enable an event trigger associated with an event */ @@ -356,6 +436,9 @@ int trace_events_enable(struct trace_instance *instance, return 1; } + retval = trace_event_enable_filter(instance, tevent); + if (retval) + return 1; retval = trace_event_enable_trigger(instance, tevent); if (retval) diff --git a/tools/tracing/rtla/src/trace.h b/tools/tracing/rtla/src/trace.h index 856b26d93064..51ad344c600b 100644 --- a/tools/tracing/rtla/src/trace.h +++ b/tools/tracing/rtla/src/trace.h @@ -6,8 +6,10 @@ struct trace_events { struct trace_events *next; char *system; char *event; + char *filter; char *trigger; char enabled; + char filter_enabled; char trigger_enabled; }; @@ -43,4 +45,5 @@ void trace_events_destroy(struct trace_instance *instance, int trace_events_enable(struct trace_instance *instance, struct trace_events *events); +int trace_event_add_filter(struct trace_events *event, char *filter); int trace_event_add_trigger(struct trace_events *event, char *trigger); -- 2.34.1