diff options
Diffstat (limited to 'tools/tracing/rtla/src/trace.c')
| -rw-r--r-- | tools/tracing/rtla/src/trace.c | 542 |
1 files changed, 542 insertions, 0 deletions
diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c new file mode 100644 index 0000000000..e1ba6d9f42 --- /dev/null +++ b/tools/tracing/rtla/src/trace.c @@ -0,0 +1,542 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE +#include <sys/sendfile.h> +#include <tracefs.h> +#include <signal.h> +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> + +#include "trace.h" +#include "utils.h" + +/* + * enable_tracer_by_name - enable a tracer on the given instance + */ +int enable_tracer_by_name(struct tracefs_instance *inst, const char *tracer_name) +{ + enum tracefs_tracers tracer; + int retval; + + tracer = TRACEFS_TRACER_CUSTOM; + + debug_msg("Enabling %s tracer\n", tracer_name); + + retval = tracefs_tracer_set(inst, tracer, tracer_name); + if (retval < 0) { + if (errno == ENODEV) + err_msg("Tracer %s not found!\n", tracer_name); + + err_msg("Failed to enable the %s tracer\n", tracer_name); + return -1; + } + + return 0; +} + +/* + * disable_tracer - set nop tracer to the insta + */ +void disable_tracer(struct tracefs_instance *inst) +{ + enum tracefs_tracers t = TRACEFS_TRACER_NOP; + int retval; + + retval = tracefs_tracer_set(inst, t); + if (retval < 0) + err_msg("Oops, error disabling tracer\n"); +} + +/* + * create_instance - create a trace instance with *instance_name + */ +struct tracefs_instance *create_instance(char *instance_name) +{ + return tracefs_instance_create(instance_name); +} + +/* + * destroy_instance - remove a trace instance and free the data + */ +void destroy_instance(struct tracefs_instance *inst) +{ + tracefs_instance_destroy(inst); + tracefs_instance_free(inst); +} + +/* + * save_trace_to_file - save the trace output of the instance to the file + */ +int save_trace_to_file(struct tracefs_instance *inst, const char *filename) +{ + const char *file = "trace"; + mode_t mode = 0644; + char buffer[4096]; + int out_fd, in_fd; + int retval = -1; + + in_fd = tracefs_instance_file_open(inst, file, O_RDONLY); + if (in_fd < 0) { + err_msg("Failed to open trace file\n"); + return -1; + } + + out_fd = creat(filename, mode); + if (out_fd < 0) { + err_msg("Failed to create output file %s\n", filename); + goto out_close_in; + } + + do { + retval = read(in_fd, buffer, sizeof(buffer)); + if (retval <= 0) + goto out_close; + + retval = write(out_fd, buffer, retval); + if (retval < 0) + goto out_close; + } while (retval > 0); + + retval = 0; +out_close: + close(out_fd); +out_close_in: + close(in_fd); + return retval; +} + +/* + * collect_registered_events - call the existing callback function for the event + * + * If an event has a registered callback function, call it. + * Otherwise, ignore the event. + */ +int +collect_registered_events(struct tep_event *event, struct tep_record *record, + int cpu, void *context) +{ + struct trace_instance *trace = context; + struct trace_seq *s = trace->seq; + + if (!event->handler) + return 0; + + event->handler(s, record, event, context); + + return 0; +} + +/* + * trace_instance_destroy - destroy and free a rtla trace instance + */ +void trace_instance_destroy(struct trace_instance *trace) +{ + if (trace->inst) { + disable_tracer(trace->inst); + destroy_instance(trace->inst); + trace->inst = NULL; + } + + if (trace->seq) { + free(trace->seq); + trace->seq = NULL; + } + + if (trace->tep) { + tep_free(trace->tep); + trace->tep = NULL; + } +} + +/* + * trace_instance_init - create an rtla trace instance + * + * It is more than the tracefs instance, as it contains other + * things required for the tracing, such as the local events and + * a seq file. + * + * Note that the trace instance is returned disabled. This allows + * the tool to apply some other configs, like setting priority + * to the kernel threads, before starting generating trace entries. + */ +int trace_instance_init(struct trace_instance *trace, char *tool_name) +{ + trace->seq = calloc(1, sizeof(*trace->seq)); + if (!trace->seq) + goto out_err; + + trace_seq_init(trace->seq); + + trace->inst = create_instance(tool_name); + if (!trace->inst) + goto out_err; + + trace->tep = tracefs_local_events(NULL); + if (!trace->tep) + goto out_err; + + /* + * Let the main enable the record after setting some other + * things such as the priority of the tracer's threads. + */ + tracefs_trace_off(trace->inst); + + return 0; + +out_err: + trace_instance_destroy(trace); + return 1; +} + +/* + * trace_instance_start - start tracing a given rtla instance + */ +int trace_instance_start(struct trace_instance *trace) +{ + return tracefs_trace_on(trace->inst); +} + +/* + * trace_events_free - free a list of trace events + */ +static void trace_events_free(struct trace_events *events) +{ + struct trace_events *tevent = events; + struct trace_events *free_event; + + while (tevent) { + free_event = tevent; + + tevent = tevent->next; + + if (free_event->filter) + free(free_event->filter); + if (free_event->trigger) + free(free_event->trigger); + free(free_event->system); + free(free_event); + } +} + +/* + * trace_event_alloc - alloc and parse a single trace event + */ +struct trace_events *trace_event_alloc(const char *event_string) +{ + struct trace_events *tevent; + + tevent = calloc(1, sizeof(*tevent)); + if (!tevent) + return NULL; + + tevent->system = strdup(event_string); + if (!tevent->system) { + free(tevent); + return NULL; + } + + tevent->event = strstr(tevent->system, ":"); + if (tevent->event) { + *tevent->event = '\0'; + tevent->event = &tevent->event[1]; + } + + 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 + */ +int trace_event_add_trigger(struct trace_events *event, char *trigger) +{ + if (event->trigger) + free(event->trigger); + + event->trigger = strdup(trigger); + if (!event->trigger) + return 1; + + 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_save_hist - save the content of an event hist + * + * If the trigger is a hist: one, save the content of the hist file. + */ +static void trace_event_save_hist(struct trace_instance *instance, + struct trace_events *tevent) +{ + int retval, index, out_fd; + mode_t mode = 0644; + char path[1024]; + char *hist; + + if (!tevent) + return; + + /* trigger enables hist */ + if (!tevent->trigger) + return; + + /* is this a hist: trigger? */ + retval = strncmp(tevent->trigger, "hist:", strlen("hist:")); + if (retval) + return; + + snprintf(path, 1024, "%s_%s_hist.txt", tevent->system, tevent->event); + + printf(" Saving event %s:%s hist to %s\n", tevent->system, tevent->event, path); + + out_fd = creat(path, mode); + if (out_fd < 0) { + err_msg(" Failed to create %s output file\n", path); + return; + } + + hist = tracefs_event_file_read(instance->inst, tevent->system, tevent->event, "hist", 0); + if (!hist) { + err_msg(" Failed to read %s:%s hist file\n", tevent->system, tevent->event); + goto out_close; + } + + index = 0; + do { + index += write(out_fd, &hist[index], strlen(hist) - index); + } while (index < strlen(hist)); + + free(hist); +out_close: + close(out_fd); +} + +/* + * trace_event_disable_trigger - disable an event trigger + */ +static void trace_event_disable_trigger(struct trace_instance *instance, + struct trace_events *tevent) +{ + char trigger[1024]; + int retval; + + if (!tevent->trigger) + return; + + if (!tevent->trigger_enabled) + return; + + debug_msg("Disabling %s:%s trigger %s\n", tevent->system, + tevent->event ? : "*", tevent->trigger); + + trace_event_save_hist(instance, tevent); + + snprintf(trigger, 1024, "!%s\n", tevent->trigger); + + retval = tracefs_event_file_write(instance->inst, tevent->system, + tevent->event, "trigger", trigger); + if (retval < 0) + err_msg("Error disabling %s:%s trigger %s\n", tevent->system, + tevent->event ? : "*", tevent->trigger); +} + +/* + * trace_events_disable - disable all trace events + */ +void trace_events_disable(struct trace_instance *instance, + struct trace_events *events) +{ + struct trace_events *tevent = events; + + if (!events) + return; + + 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); + } + + tevent->enabled = 0; + tevent = tevent->next; + } +} + +/* + * 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 + */ +static int trace_event_enable_trigger(struct trace_instance *instance, + struct trace_events *tevent) +{ + char trigger[1024]; + int retval; + + if (!tevent->trigger) + return 0; + + if (!tevent->event) { + err_msg("Trigger %s applies only for single events, not for all %s:* events\n", + tevent->trigger, tevent->system); + return 1; + } + + snprintf(trigger, 1024, "%s\n", tevent->trigger); + + debug_msg("Enabling %s:%s trigger %s\n", tevent->system, + tevent->event ? : "*", tevent->trigger); + + retval = tracefs_event_file_write(instance->inst, tevent->system, + tevent->event, "trigger", trigger); + if (retval < 0) { + err_msg("Error enabling %s:%s trigger %s\n", tevent->system, + tevent->event ? : "*", tevent->trigger); + return 1; + } + + tevent->trigger_enabled = 1; + + return 0; +} + +/* + * trace_events_enable - enable all events + */ +int trace_events_enable(struct trace_instance *instance, + struct trace_events *events) +{ + struct trace_events *tevent = events; + int retval; + + while (tevent) { + debug_msg("Enabling event %s:%s\n", tevent->system, tevent->event ? : "*"); + retval = tracefs_event_enable(instance->inst, tevent->system, tevent->event); + if (retval < 0) { + err_msg("Error enabling event %s:%s\n", tevent->system, + tevent->event ? : "*"); + return 1; + } + + retval = trace_event_enable_filter(instance, tevent); + if (retval) + return 1; + + retval = trace_event_enable_trigger(instance, tevent); + if (retval) + return 1; + + tevent->enabled = 1; + tevent = tevent->next; + } + + return 0; +} + +/* + * trace_events_destroy - disable and free all trace events + */ +void trace_events_destroy(struct trace_instance *instance, + struct trace_events *events) +{ + if (!events) + return; + + trace_events_disable(instance, events); + trace_events_free(events); +} + +int trace_is_off(struct trace_instance *tool, struct trace_instance *trace) +{ + /* + * The tool instance is always present, it is the one used to collect + * data. + */ + if (!tracefs_trace_is_on(tool->inst)) + return 1; + + /* + * The trace instance is only enabled when -t is set. IOW, when the system + * is tracing. + */ + if (trace && !tracefs_trace_is_on(trace->inst)) + return 1; + + return 0; +} |