/*
   * builtin-inject.c
   *
   * Builtin inject command: Examine the live mode (stdin) event stream
   * and repipe it to stdout while optionally injecting additional
   * events into it.
   */
  #include "builtin.h"
  
  #include "perf.h"
  #include "util/color.h"
  #include "util/evlist.h"
  #include "util/evsel.h"
  #include "util/session.h"
  #include "util/tool.h"
  #include "util/debug.h"
  #include "util/build-id.h"
  #include "util/data.h"
  
  #include "util/parse-options.h"
  
  #include <linux/list.h>
  
  struct perf_inject {
  	struct perf_tool	tool;
  	bool			build_ids;
  	bool			sched_stat;
  	const char		*input_name;
  	struct perf_data_file	output;
  	u64			bytes_written;
  	struct list_head	samples;
  };
  
  struct event_entry {
  	struct list_head node;
  	u32		 tid;
  	union perf_event event[0];
  };
  
  static int perf_event__repipe_synth(struct perf_tool *tool,
  				    union perf_event *event)
  {
  	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
  	ssize_t size;
  
  	size = perf_data_file__write(&inject->output, event,
  				     event->header.size);
  	if (size < 0)
  		return -errno;
  
  	inject->bytes_written += size;
  	return 0;
  }
  
  static int perf_event__repipe_op2_synth(struct perf_tool *tool,
  					union perf_event *event,
  					struct perf_session *session
  					__maybe_unused)
  {
  	return perf_event__repipe_synth(tool, event);
  }
  
  static int perf_event__repipe_attr(struct perf_tool *tool,
  				   union perf_event *event,
  				   struct perf_evlist **pevlist)
  {
  	struct perf_inject *inject = container_of(tool, struct perf_inject,
  						  tool);
  	int ret;
  
  	ret = perf_event__process_attr(tool, event, pevlist);
  	if (ret)
  		return ret;
  
  	if (&inject->output.is_pipe)
  		return 0;
  
  	return perf_event__repipe_synth(tool, event);
  }
  
  static int perf_event__repipe(struct perf_tool *tool,
  			      union perf_event *event,
  			      struct perf_sample *sample __maybe_unused,
  			      struct machine *machine __maybe_unused)
  {
  	return perf_event__repipe_synth(tool, event);
  }
  
  typedef int (*inject_handler)(struct perf_tool *tool,
  			      union perf_event *event,
  			      struct perf_sample *sample,
  			      struct perf_evsel *evsel,
  			      struct machine *machine);
  
  static int perf_event__repipe_sample(struct perf_tool *tool,
  				     union perf_event *event,
  				     struct perf_sample *sample,
  				     struct perf_evsel *evsel,
  				     struct machine *machine)
  {
  	if (evsel->handler) {
  		inject_handler f = evsel->handler;
  		return f(tool, event, sample, evsel, machine);
  	}
  
  	build_id__mark_dso_hit(tool, event, sample, evsel, machine);
  
  	return perf_event__repipe_synth(tool, event);
  }
  
  static int perf_event__repipe_mmap(struct perf_tool *tool,
  				   union perf_event *event,
  				   struct perf_sample *sample,
  				   struct machine *machine)
  {
  	int err;
  
  	err = perf_event__process_mmap(tool, event, sample, machine);
  	perf_event__repipe(tool, event, sample, machine);
  
  	return err;
  }
  
  static int perf_event__repipe_mmap2(struct perf_tool *tool,
  				   union perf_event *event,
  				   struct perf_sample *sample,
  				   struct machine *machine)
  {
  	int err;
  
  	err = perf_event__process_mmap2(tool, event, sample, machine);
  	perf_event__repipe(tool, event, sample, machine);
  
  	return err;
  }
  
  static int perf_event__repipe_fork(struct perf_tool *tool,
  				   union perf_event *event,
  				   struct perf_sample *sample,
  				   struct machine *machine)
  {
  	int err;
  
  	err = perf_event__process_fork(tool, event, sample, machine);
  	perf_event__repipe(tool, event, sample, machine);
  
  	return err;
  }
  
  static int perf_event__repipe_tracing_data(struct perf_tool *tool,
  					   union perf_event *event,
  					   struct perf_session *session)
  {
  	int err;
  
  	perf_event__repipe_synth(tool, event);
  	err = perf_event__process_tracing_data(tool, event, session);
  
  	return err;
  }
  
  static int dso__read_build_id(struct dso *dso)
  {
  	if (dso->has_build_id)
  		return 0;
  
  	if (filename__read_build_id(dso->long_name, dso->build_id,
  				    sizeof(dso->build_id)) > 0) {
  		dso->has_build_id = true;
  		return 0;
  	}
  
  	return -1;
  }
  
  static int dso__inject_build_id(struct dso *dso, struct perf_tool *tool,
  				struct machine *machine)
  {
  	u16 misc = PERF_RECORD_MISC_USER;
  	int err;
  
  	if (dso__read_build_id(dso) < 0) {
  		pr_debug("no build_id found for %s
  ", dso->long_name);
  		return -1;
  	}
  
  	if (dso->kernel)
  		misc = PERF_RECORD_MISC_KERNEL;
  
  	err = perf_event__synthesize_build_id(tool, dso, misc, perf_event__repipe,
  					      machine);
  	if (err) {
  		pr_err("Can't synthesize build_id event for %s
  ", dso->long_name);
  		return -1;
  	}
  
  	return 0;
  }
  
  static int perf_event__inject_buildid(struct perf_tool *tool,
  				      union perf_event *event,
  				      struct perf_sample *sample,
  				      struct perf_evsel *evsel __maybe_unused,
  				      struct machine *machine)
  {
  	struct addr_location al;
  	struct thread *thread;
  	u8 cpumode;
  
  	cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
  
  	thread = machine__findnew_thread(machine, sample->pid, sample->pid);
  	if (thread == NULL) {
  		pr_err("problem processing %d event, skipping it.
  ",
  		       event->header.type);
  		goto repipe;
  	}
  
  	thread__find_addr_map(thread, machine, cpumode, MAP__FUNCTION,
  			      sample->ip, &al);
  
  	if (al.map != NULL) {
  		if (!al.map->dso->hit) {
  			al.map->dso->hit = 1;
  			if (map__load(al.map, NULL) >= 0) {
  				dso__inject_build_id(al.map->dso, tool, machine);
  				/*
  				 * If this fails, too bad, let the other side
  				 * account this as unresolved.
  				 */
  			} else {
  #ifdef HAVE_LIBELF_SUPPORT
  				pr_warning("no symbols found in %s, maybe "
  					   "install a debug package?
  ",
  					   al.map->dso->long_name);
  #endif
  			}
  		}
  	}
  
  repipe:
  	perf_event__repipe(tool, event, sample, machine);
  	return 0;
  }
  
  static int perf_inject__sched_process_exit(struct perf_tool *tool,
  					   union perf_event *event __maybe_unused,
  					   struct perf_sample *sample,
  					   struct perf_evsel *evsel __maybe_unused,
  					   struct machine *machine __maybe_unused)
  {
  	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
  	struct event_entry *ent;
  
  	list_for_each_entry(ent, &inject->samples, node) {
  		if (sample->tid == ent->tid) {
  			list_del_init(&ent->node);
  			free(ent);
  			break;
  		}
  	}
  
  	return 0;
  }
  
  static int perf_inject__sched_switch(struct perf_tool *tool,
  				     union perf_event *event,
  				     struct perf_sample *sample,
  				     struct perf_evsel *evsel,
  				     struct machine *machine)
  {
  	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
  	struct event_entry *ent;
  
  	perf_inject__sched_process_exit(tool, event, sample, evsel, machine);
  
  	ent = malloc(event->header.size + sizeof(struct event_entry));
  	if (ent == NULL) {
  		color_fprintf(stderr, PERF_COLOR_RED,
  			     "Not enough memory to process sched switch event!");
  		return -1;
  	}
  
  	ent->tid = sample->tid;
  	memcpy(&ent->event, event, event->header.size);
  	list_add(&ent->node, &inject->samples);
  	return 0;
  }
  
  static int perf_inject__sched_stat(struct perf_tool *tool,
  				   union perf_event *event __maybe_unused,
  				   struct perf_sample *sample,
  				   struct perf_evsel *evsel,
  				   struct machine *machine)
  {
  	struct event_entry *ent;
  	union perf_event *event_sw;
  	struct perf_sample sample_sw;
  	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
  	u32 pid = perf_evsel__intval(evsel, sample, "pid");
  
  	list_for_each_entry(ent, &inject->samples, node) {
  		if (pid == ent->tid)
  			goto found;
  	}
  
  	return 0;
  found:
  	event_sw = &ent->event[0];
  	perf_evsel__parse_sample(evsel, event_sw, &sample_sw);
  
  	sample_sw.period = sample->period;
  	sample_sw.time	 = sample->time;
  	perf_event__synthesize_sample(event_sw, evsel->attr.sample_type,
  				      evsel->attr.sample_regs_user,
  				      evsel->attr.read_format, &sample_sw,
  				      false);
  	build_id__mark_dso_hit(tool, event_sw, &sample_sw, evsel, machine);
  	return perf_event__repipe(tool, event_sw, &sample_sw, machine);
  }
  
  static void sig_handler(int sig __maybe_unused)
  {
  	session_done = 1;
  }
  
  static int perf_evsel__check_stype(struct perf_evsel *evsel,
  				   u64 sample_type, const char *sample_msg)
  {
  	struct perf_event_attr *attr = &evsel->attr;
  	const char *name = perf_evsel__name(evsel);
  
  	if (!(attr->sample_type & sample_type)) {
  		pr_err("Samples for %s event do not have %s attribute set.",
  			name, sample_msg);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int __cmd_inject(struct perf_inject *inject)
  {
  	struct perf_session *session;
  	int ret = -EINVAL;
  	struct perf_data_file file = {
  		.path = inject->input_name,
  		.mode = PERF_DATA_MODE_READ,
  	};
  	struct perf_data_file *file_out = &inject->output;
  
  	signal(SIGINT, sig_handler);
  
  	if (inject->build_ids || inject->sched_stat) {
  		inject->tool.mmap	  = perf_event__repipe_mmap;
  		inject->tool.mmap2	  = perf_event__repipe_mmap2;
  		inject->tool.fork	  = perf_event__repipe_fork;
  		inject->tool.tracing_data = perf_event__repipe_tracing_data;
  	}
  
  	session = perf_session__new(&file, true, &inject->tool);
  	if (session == NULL)
  		return -ENOMEM;
  
  	if (inject->build_ids) {
  		inject->tool.sample = perf_event__inject_buildid;
  	} else if (inject->sched_stat) {
  		struct perf_evsel *evsel;
  
  		inject->tool.ordered_samples = true;
  
  		evlist__for_each(session->evlist, evsel) {
  			const char *name = perf_evsel__name(evsel);
  
  			if (!strcmp(name, "sched:sched_switch")) {
  				if (perf_evsel__check_stype(evsel, PERF_SAMPLE_TID, "TID"))
  					return -EINVAL;
  
  				evsel->handler = perf_inject__sched_switch;
  			} else if (!strcmp(name, "sched:sched_process_exit"))
  				evsel->handler = perf_inject__sched_process_exit;
  			else if (!strncmp(name, "sched:sched_stat_", 17))
  				evsel->handler = perf_inject__sched_stat;
  		}
  	}
  
  	if (!file_out->is_pipe)
  		lseek(file_out->fd, session->header.data_offset, SEEK_SET);
  
  	ret = perf_session__process_events(session, &inject->tool);
  
  	if (!file_out->is_pipe) {
  		session->header.data_size = inject->bytes_written;
  		perf_session__write_header(session, session->evlist, file_out->fd, true);
  	}
  
  	perf_session__delete(session);
  
  	return ret;
  }
  
  int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
  {
  	struct perf_inject inject = {
  		.tool = {
  			.sample		= perf_event__repipe_sample,
  			.mmap		= perf_event__repipe,
  			.mmap2		= perf_event__repipe,
  			.comm		= perf_event__repipe,
  			.fork		= perf_event__repipe,
  			.exit		= perf_event__repipe,
  			.lost		= perf_event__repipe,
  			.read		= perf_event__repipe_sample,
  			.throttle	= perf_event__repipe,
  			.unthrottle	= perf_event__repipe,
  			.attr		= perf_event__repipe_attr,
  			.tracing_data	= perf_event__repipe_op2_synth,
  			.finished_round	= perf_event__repipe_op2_synth,
  			.build_id	= perf_event__repipe_op2_synth,
  		},
  		.input_name  = "-",
  		.samples = LIST_HEAD_INIT(inject.samples),
  		.output = {
  			.path = "-",
  			.mode = PERF_DATA_MODE_WRITE,
  		},
  	};
  	const struct option options[] = {
  		OPT_BOOLEAN('b', "build-ids", &inject.build_ids,
  			    "Inject build-ids into the output stream"),
  		OPT_STRING('i', "input", &inject.input_name, "file",
  			   "input file name"),
  		OPT_STRING('o', "output", &inject.output.path, "file",
  			   "output file name"),
  		OPT_BOOLEAN('s', "sched-stat", &inject.sched_stat,
  			    "Merge sched-stat and sched-switch for getting events "
  			    "where and how long tasks slept"),
  		OPT_INCR('v', "verbose", &verbose,
  			 "be more verbose (show build ids, etc)"),
  		OPT_END()
  	};
  	const char * const inject_usage[] = {
  		"perf inject [<options>]",
  		NULL
  	};
  
  	argc = parse_options(argc, argv, options, inject_usage, 0);
  
  	/*
  	 * Any (unrecognized) arguments left?
  	 */
  	if (argc)
  		usage_with_options(inject_usage, options);
  
  	if (perf_data_file__open(&inject.output)) {
  		perror("failed to create output file");
  		return -1;
  	}
  
  	if (symbol__init() < 0)
  		return -1;
  
  	return __cmd_inject(&inject);
  }