text: #define _FILE_OFFSET_BITS 64
  
  #include <linux/kernel.h>
  
  #include <byteswap.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/mman.h>
  
  #include "evlist.h"
  #include "evsel.h"
  #include "session.h"
  #include "sort.h"
  #include "util.h"
  
  static int perf_session__open(struct perf_session *self, bool force)
  {
  	struct stat input_stat;
  
  	if (!strcmp(self->filename, "-")) {
  		self->fd_pipe = true;
  		self->fd = STDIN_FILENO;
  
  		if (perf_session__read_header(self, self->fd) < 0)
  			pr_err("incompatible file format");
  
  		return 0;
  	}
  
  	self->fd = open(self->filename, O_RDONLY);
  	if (self->fd < 0) {
  		int err = errno;
  
  		pr_err("failed to open %s: %s", self->filename, strerror(err));
  		if (err == ENOENT && !strcmp(self->filename, "perf.data"))
  			pr_err("  (try 'perf record' first)");
  		pr_err("\n");
  		return -errno;
  	}
  
  	if (fstat(self->fd, &input_stat) < 0)
  		goto out_close;
  
  	if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
  		pr_err("file %s not owned by current user or root\n",
  		       self->filename);
  		goto out_close;
  	}
  
  	if (!input_stat.st_size) {
  		pr_info("zero-sized file (%s), nothing to do!\n",
  			self->filename);
  		goto out_close;
  	}
  
  	if (perf_session__read_header(self, self->fd) < 0) {
  		pr_err("incompatible file format");
  		goto out_close;
  	}
  
  	if (!perf_evlist__valid_sample_type(self->evlist)) {
  		pr_err("non matching sample_type");
  		goto out_close;
  	}
  
  	if (!perf_evlist__valid_sample_id_all(self->evlist)) {
  		pr_err("non matching sample_id_all");
  		goto out_close;
  	}
  
  	self->size = input_stat.st_size;
  	return 0;
  
  out_close:
  	close(self->fd);
  	self->fd = -1;
  	return -1;
  }
  
  static void perf_session__id_header_size(struct perf_session *session)
  {
         struct perf_sample *data;
         u64 sample_type = session->sample_type;
         u16 size = 0;
  
  	if (!session->sample_id_all)
  		goto out;
  
         if (sample_type & PERF_SAMPLE_TID)
                 size += sizeof(data->tid) * 2;
  
         if (sample_type & PERF_SAMPLE_TIME)
                 size += sizeof(data->time);
  
         if (sample_type & PERF_SAMPLE_ID)
                 size += sizeof(data->id);
  
         if (sample_type & PERF_SAMPLE_STREAM_ID)
                 size += sizeof(data->stream_id);
  
         if (sample_type & PERF_SAMPLE_CPU)
                 size += sizeof(data->cpu) * 2;
  out:
         session->id_hdr_size = size;
  }
  
  void perf_session__update_sample_type(struct perf_session *self)
  {
  	self->sample_type = perf_evlist__sample_type(self->evlist);
  	self->sample_size = __perf_evsel__sample_size(self->sample_type);
  	self->sample_id_all = perf_evlist__sample_id_all(self->evlist);
  	perf_session__id_header_size(self);
  }
  
  int perf_session__create_kernel_maps(struct perf_session *self)
  {
  	int ret = machine__create_kernel_maps(&self->host_machine);
  
  	if (ret >= 0)
  		ret = machines__create_guest_kernel_maps(&self->machines);
  	return ret;
  }
  
  static void perf_session__destroy_kernel_maps(struct perf_session *self)
  {
  	machine__destroy_kernel_maps(&self->host_machine);
  	machines__destroy_guest_kernel_maps(&self->machines);
  }
  
  struct perf_session *perf_session__new(const char *filename, int mode,
  				       bool force, bool repipe,
  				       struct perf_event_ops *ops)
  {
  	size_t len = filename ? strlen(filename) + 1 : 0;
  	struct perf_session *self = zalloc(sizeof(*self) + len);
  
  	if (self == NULL)
  		goto out;
  
  	memcpy(self->filename, filename, len);
  	self->threads = RB_ROOT;
  	INIT_LIST_HEAD(&self->dead_threads);
  	self->last_match = NULL;
  	/*
  	 * On 64bit we can mmap the data file in one go. No need for tiny mmap
  	 * slices. On 32bit we use 32MB.
  	 */
  #if BITS_PER_LONG == 64
  	self->mmap_window = ULLONG_MAX;
  #else
  	self->mmap_window = 32 * 1024 * 1024ULL;
  #endif
  	self->machines = RB_ROOT;
  	self->repipe = repipe;
  	INIT_LIST_HEAD(&self->ordered_samples.samples);
  	INIT_LIST_HEAD(&self->ordered_samples.sample_cache);
  	INIT_LIST_HEAD(&self->ordered_samples.to_free);
  	machine__init(&self->host_machine, "", HOST_KERNEL_ID);
  
  	if (mode == O_RDONLY) {
  		if (perf_session__open(self, force) < 0)
  			goto out_delete;
  		perf_session__update_sample_type(self);
  	} else if (mode == O_WRONLY) {
  		/*
  		 * In O_RDONLY mode this will be performed when reading the
  		 * kernel MMAP event, in perf_event__process_mmap().
  		 */
  		if (perf_session__create_kernel_maps(self) < 0)
  			goto out_delete;
  	}
  
  	if (ops && ops->ordering_requires_timestamps &&
  	    ops->ordered_samples && !self->sample_id_all) {
  		dump_printf("WARNING: No sample_id_all support, falling back to unordered processing\n");
  		ops->ordered_samples = false;
  	}
  
  out:
  	return self;
  out_delete:
  	perf_session__delete(self);
  	return NULL;
  }
  
  static void perf_session__delete_dead_threads(struct perf_session *self)
  {
  	struct thread *n, *t;
  
  	list_for_each_entry_safe(t, n, &self->dead_threads, node) {
  		list_del(&t->node);
  		thread__delete(t);
  	}
  }
  
  static void perf_session__delete_threads(struct perf_session *self)
  {
  	struct rb_node *nd = rb_first(&self->threads);
  
  	while (nd) {
  		struct thread *t = rb_entry(nd, struct thread, rb_node);
  
  		rb_erase(&t->rb_node, &self->threads);
  		nd = rb_next(nd);
  		thread__delete(t);
  	}
  }
  
  void perf_session__delete(struct perf_session *self)
  {
  	perf_session__destroy_kernel_maps(self);
  	perf_session__delete_dead_threads(self);
  	perf_session__delete_threads(self);
  	machine__exit(&self->host_machine);
  	close(self->fd);
  	free(self);
  }
  
  void perf_session__remove_thread(struct perf_session *self, struct thread *th)
  {
  	self->last_match = NULL;
  	rb_erase(&th->rb_node, &self->threads);
  	/*
  	 * We may have references to this thread, for instance in some hist_entry
  	 * instances, so just move them to a separate list.
  	 */
  	list_add_tail(&th->node, &self->dead_threads);
  }
  
  static bool symbol__match_parent_regex(struct symbol *sym)
  {
  	if (sym->name && !regexec(&parent_regex, sym->name, 0, NULL, 0))
  		return 1;
  
  	return 0;
  }
  
  int perf_session__resolve_callchain(struct perf_session *self,
  				    struct thread *thread,
  				    struct ip_callchain *chain,
  				    struct symbol **parent)
  {
  	u8 cpumode = PERF_RECORD_MISC_USER;
  	unsigned int i;
  	int err;
  
  	callchain_cursor_reset(&self->callchain_cursor);
  
  	for (i = 0; i < chain->nr; i++) {
  		u64 ip = chain->ips[i];
  		struct addr_location al;
  
  		if (ip >= PERF_CONTEXT_MAX) {
  			switch (ip) {
  			case PERF_CONTEXT_HV:
  				cpumode = PERF_RECORD_MISC_HYPERVISOR;	break;
  			case PERF_CONTEXT_KERNEL:
  				cpumode = PERF_RECORD_MISC_KERNEL;	break;
  			case PERF_CONTEXT_USER:
  				cpumode = PERF_RECORD_MISC_USER;	break;
  			default:
  				break;
  			}
  			continue;
  		}
  
  		al.filtered = false;
  		thread__find_addr_location(thread, self, cpumode,
  				MAP__FUNCTION, thread->pid, ip, &al, NULL);
  		if (al.sym != NULL) {
  			if (sort__has_parent && !*parent &&
  			    symbol__match_parent_regex(al.sym))
  				*parent = al.sym;
  			if (!symbol_conf.use_callchain)
  				break;
  		}
  
  		err = callchain_cursor_append(&self->callchain_cursor,
  					      ip, al.map, al.sym);
  		if (err)
  			return err;
  	}
  
  	return 0;
  }
  
  static int process_event_synth_stub(union perf_event *event __used,
  				    struct perf_session *session __used)
  {
  	dump_printf(": unhandled!\n");
  	return 0;
  }
  
  static int process_event_sample_stub(union perf_event *event __used,
  				     struct perf_sample *sample __used,
  				     struct perf_evsel *evsel __used,
  				     struct perf_session *session __used)
  {
  	dump_printf(": unhandled!\n");
  	return 0;
  }
  
  static int process_event_stub(union perf_event *event __used,
  			      struct perf_sample *sample __used,
  			      struct perf_session *session __used)
  {
  	dump_printf(": unhandled!\n");
  	return 0;
  }
  
  static int process_finished_round_stub(union perf_event *event __used,
  				       struct perf_session *session __used,
  				       struct perf_event_ops *ops __used)
  {
  	dump_printf(": unhandled!\n");
  	return 0;
  }
  
  static int process_finished_round(union perf_event *event,
  				  struct perf_session *session,
  				  struct perf_event_ops *ops);
  
  static void perf_event_ops__fill_defaults(struct perf_event_ops *handler)
  {
  	if (handler->sample == NULL)
  		handler->sample = process_event_sample_stub;
  	if (handler->mmap == NULL)
  		handler->mmap = process_event_stub;
  	if (handler->comm == NULL)
  		handler->comm = process_event_stub;
  	if (handler->fork == NULL)
  		handler->fork = process_event_stub;
  	if (handler->exit == NULL)
  		handler->exit = process_event_stub;
  	if (handler->lost == NULL)
  		handler->lost = perf_event__process_lost;
  	if (handler->read == NULL)
  		handler->read = process_event_stub;
  	if (handler->throttle == NULL)
  		handler->throttle = process_event_stub;
  	if (handler->unthrottle == NULL)
  		handler->unthrottle = process_event_stub;
  	if (handler->attr == NULL)
  		handler->attr = process_event_synth_stub;
  	if (handler->event_type == NULL)
  		handler->event_type = process_event_synth_stub;
  	if (handler->tracing_data == NULL)
  		handler->tracing_data = process_event_synth_stub;
  	if (handler->build_id == NULL)
  		handler->build_id = process_event_synth_stub;
  	if (handler->finished_round == NULL) {
  		if (handler->ordered_samples)
  			handler->finished_round = process_finished_round;
  		else
  			handler->finished_round = process_finished_round_stub;
  	}
  }
  
  void mem_bswap_64(void *src, int byte_size)
  {
  	u64 *m = src;
  
  	while (byte_size > 0) {
  		*m = bswap_64(*m);
  		byte_size -= sizeof(u64);
  		++m;
  	}
  }
  
  static void perf_event__all64_swap(union perf_event *event)
  {
  	struct perf_event_header *hdr = &event->header;
  	mem_bswap_64(hdr + 1, event->header.size - sizeof(*hdr));
  }
  
  static void perf_event__comm_swap(union perf_event *event)
  {
  	event->comm.pid = bswap_32(event->comm.pid);
  	event->comm.tid = bswap_32(event->comm.tid);
  }
  
  static void perf_event__mmap_swap(union perf_event *event)
  {
  	event->mmap.pid	  = bswap_32(event->mmap.pid);
  	event->mmap.tid	  = bswap_32(event->mmap.tid);
  	event->mmap.start = bswap_64(event->mmap.start);
  	event->mmap.len	  = bswap_64(event->mmap.len);
  	event->mmap.pgoff = bswap_64(event->mmap.pgoff);
  }
  
  static void perf_event__task_swap(union perf_event *event)
  {
  	event->fork.pid	 = bswap_32(event->fork.pid);
  	event->fork.tid	 = bswap_32(event->fork.tid);
  	event->fork.ppid = bswap_32(event->fork.ppid);
  	event->fork.ptid = bswap_32(event->fork.ptid);
  	event->fork.time = bswap_64(event->fork.time);
  }
  
  static void perf_event__read_swap(union perf_event *event)
  {
  	event->read.pid		 = bswap_32(event->read.pid);
  	event->read.tid		 = bswap_32(event->read.tid);
  	event->read.value	 = bswap_64(event->read.value);
  	event->read.time_enabled = bswap_64(event->read.time_enabled);
  	event->read.time_running = bswap_64(event->read.time_running);
  	event->read.id		 = bswap_64(event->read.id);
  }
  
  /* exported for swapping attributes in file header */
  void perf_event__attr_swap(struct perf_event_attr *attr)
  {
  	attr->type		= bswap_32(attr->type);
  	attr->size		= bswap_32(attr->size);
  	attr->config		= bswap_64(attr->config);
  	attr->sample_period	= bswap_64(attr->sample_period);
  	attr->sample_type	= bswap_64(attr->sample_type);
  	attr->read_format	= bswap_64(attr->read_format);
  	attr->wakeup_events	= bswap_32(attr->wakeup_events);
  	attr->bp_type		= bswap_32(attr->bp_type);
  	attr->bp_addr		= bswap_64(attr->bp_addr);
  	attr->bp_len		= bswap_64(attr->bp_len);
  }
  
  static void perf_event__hdr_attr_swap(union perf_event *event)
  {
  	size_t size;
  
  	perf_event__attr_swap(&event->attr.attr);
  
  	size = event->header.size;
  	size -= (void *)&event->attr.id - (void *)event;
  	mem_bswap_64(event->attr.id, size);
  }
  
  static void perf_event__event_type_swap(union perf_event *event)
  {
  	event->event_type.event_type.event_id =
  		bswap_64(event->event_type.event_type.event_id);
  }
  
  static void perf_event__tracing_data_swap(union perf_event *event)
  {
  	event->tracing_data.size = bswap_32(event->tracing_data.size);
  }
  
  typedef void (*perf_event__swap_op)(union perf_event *event);
  
  static perf_event__swap_op perf_event__swap_ops[] = {
  	[PERF_RECORD_MMAP]		  = perf_event__mmap_swap,
  	[PERF_RECORD_COMM]		  = perf_event__comm_swap,
  	[PERF_RECORD_FORK]		  = perf_event__task_swap,
  	[PERF_RECORD_EXIT]		  = perf_event__task_swap,
  	[PERF_RECORD_LOST]		  = perf_event__all64_swap,
  	[PERF_RECORD_READ]		  = perf_event__read_swap,
  	[PERF_RECORD_SAMPLE]		  = perf_event__all64_swap,
  	[PERF_RECORD_HEADER_ATTR]	  = perf_event__hdr_attr_swap,
  	[PERF_RECORD_HEADER_EVENT_TYPE]	  = perf_event__event_type_swap,
  	[PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
  	[PERF_RECORD_HEADER_BUILD_ID]	  = NULL,
  	[PERF_RECORD_HEADER_MAX]	  = NULL,
  };
  
  struct sample_queue {
  	u64			timestamp;
  	u64			file_offset;
  	union perf_event	*event;
  	struct list_head	list;
  };
  
  static void perf_session_free_sample_buffers(struct perf_session *session)
  {
  	struct ordered_samples *os = &session->ordered_samples;
  
  	while (!list_empty(&os->to_free)) {
  		struct sample_queue *sq;
  
  		sq = list_entry(os->to_free.next, struct sample_queue, list);
  		list_del(&sq->list);
  		free(sq);
  	}
  }
  
  static int perf_session_deliver_event(struct perf_session *session,
  				      union perf_event *event,
  				      struct perf_sample *sample,
  				      struct perf_event_ops *ops,
  				      u64 file_offset);
  
  static void flush_sample_queue(struct perf_session *s,
  			       struct perf_event_ops *ops)
  {
  	struct ordered_samples *os = &s->ordered_samples;
  	struct list_head *head = &os->samples;
  	struct sample_queue *tmp, *iter;
  	struct perf_sample sample;
  	u64 limit = os->next_flush;
  	u64 last_ts = os->last_sample ? os->last_sample->timestamp : 0ULL;
  	int ret;
  
  	if (!ops->ordered_samples || !limit)
  		return;
  
  	list_for_each_entry_safe(iter, tmp, head, list) {
  		if (iter->timestamp > limit)
  			break;
  
  		ret = perf_session__parse_sample(s, iter->event, &sample);
  		if (ret)
  			pr_err("Can't parse sample, err = %d\n", ret);
  		else
  			perf_session_deliver_event(s, iter->event, &sample, ops,
  						   iter->file_offset);
  
  		os->last_flush = iter->timestamp;
  		list_del(&iter->list);
  		list_add(&iter->list, &os->sample_cache);
  	}
  
  	if (list_empty(head)) {
  		os->last_sample = NULL;
  	} else if (last_ts <= limit) {
  		os->last_sample =
  			list_entry(head->prev, struct sample_queue, list);
  	}
  }
  
  /*
   * When perf record finishes a pass on every buffers, it records this pseudo
   * event.
   * We record the max timestamp t found in the pass n.
   * Assuming these timestamps are monotonic across cpus, we know that if
   * a buffer still has events with timestamps below t, they will be all
   * available and then read in the pass n + 1.
   * Hence when we start to read the pass n + 2, we can safely flush every
   * events with timestamps below t.
   *
   *    ============ PASS n =================
   *       CPU 0         |   CPU 1
   *                     |
   *    cnt1 timestamps  |   cnt2 timestamps
   *          1          |         2
   *          2          |         3
   *          -          |         4  <--- max recorded
   *
   *    ============ PASS n + 1 ==============
   *       CPU 0         |   CPU 1
   *                     |
   *    cnt1 timestamps  |   cnt2 timestamps
   *          3          |         5
   *          4          |         6
   *          5          |         7 <---- max recorded
   *
   *      Flush every events below timestamp 4
   *
   *    ============ PASS n + 2 ==============
   *       CPU 0         |   CPU 1
   *                     |
   *    cnt1 timestamps  |   cnt2 timestamps
   *          6          |         8
   *          7          |         9
   *          -          |         10
   *
   *      Flush every events below timestamp 7
   *      etc...
   */
  static int process_finished_round(union perf_event *event __used,
  				  struct perf_session *session,
  				  struct perf_event_ops *ops)
  {
  	flush_sample_queue(session, ops);
  	session->ordered_samples.next_flush = session->ordered_samples.max_timestamp;
  
  	return 0;
  }
  
  /* The queue is ordered by time */
  static void __queue_event(struct sample_queue *new, struct perf_session *s)
  {
  	struct ordered_samples *os = &s->ordered_samples;
  	struct sample_queue *sample = os->last_sample;
  	u64 timestamp = new->timestamp;
  	struct list_head *p;
  
  	os->last_sample = new;
  
  	if (!sample) {
  		list_add(&new->list, &os->samples);
  		os->max_timestamp = timestamp;
  		return;
  	}
  
  	/*
  	 * last_sample might point to some random place in the list as it's
  	 * the last queued event. We expect that the new event is close to
  	 * this.
  	 */
  	if (sample->timestamp <= timestamp) {
  		while (sample->timestamp <= timestamp) {
  			p = sample->list.next;
  			if (p == &os->samples) {
  				list_add_tail(&new->list, &os->samples);
  				os->max_timestamp = timestamp;
  				return;
  			}
  			sample = list_entry(p, struct sample_queue, list);
  		}
  		list_add_tail(&new->list, &sample->list);
  	} else {
  		while (sample->timestamp > timestamp) {
  			p = sample->list.prev;
  			if (p == &os->samples) {
  				list_add(&new->list, &os->samples);
  				return;
  			}
  			sample = list_entry(p, struct sample_queue, list);
  		}
  		list_add(&new->list, &sample->list);
  	}
  }
  
  #define MAX_SAMPLE_BUFFER	(64 * 1024 / sizeof(struct sample_queue))
  
  static int perf_session_queue_event(struct perf_session *s, union perf_event *event,
  				    struct perf_sample *sample, u64 file_offset)
  {
  	struct ordered_samples *os = &s->ordered_samples;
  	struct list_head *sc = &os->sample_cache;
  	u64 timestamp = sample->time;
  	struct sample_queue *new;
  
  	if (!timestamp || timestamp == ~0ULL)
  		return -ETIME;
  
  	if (timestamp < s->ordered_samples.last_flush) {
  		printf("Warning: Timestamp below last timeslice flush\n");
  		return -EINVAL;
  	}
  
  	if (!list_empty(sc)) {
  		new = list_entry(sc->next, struct sample_queue, list);
  		list_del(&new->list);
  	} else if (os->sample_buffer) {
  		new = os->sample_buffer + os->sample_buffer_idx;
  		if (++os->sample_buffer_idx == MAX_SAMPLE_BUFFER)
  			os->sample_buffer = NULL;
  	} else {
  		os->sample_buffer = malloc(MAX_SAMPLE_BUFFER * sizeof(*new));
  		if (!os->sample_buffer)
  			return -ENOMEM;
  		list_add(&os->sample_buffer->list, &os->to_free);
  		os->sample_buffer_idx = 2;
  		new = os->sample_buffer + 1;
  	}
  
  	new->timestamp = timestamp;
  	new->file_offset = file_offset;
  	new->event = event;
  
  	__queue_event(new, s);
  
  	return 0;
  }
  
  static void callchain__printf(struct perf_sample *sample)
  {
  	unsigned int i;
  
  	printf("... chain: nr:%" PRIu64 "\n", sample->callchain->nr);
  
  	for (i = 0; i < sample->callchain->nr; i++)
  		printf("..... %2d: %016" PRIx64 "\n",
  		       i, sample->callchain->ips[i]);
  }
  
  static void perf_session__print_tstamp(struct perf_session *session,
  				       union perf_event *event,
  				       struct perf_sample *sample)
  {
  	if (event->header.type != PERF_RECORD_SAMPLE &&
  	    !session->sample_id_all) {
  		fputs("-1 -1 ", stdout);
  		return;
  	}
  
  	if ((session->sample_type & PERF_SAMPLE_CPU))
  		printf("%u ", sample->cpu);
  
  	if (session->sample_type & PERF_SAMPLE_TIME)
  		printf("%" PRIu64 " ", sample->time);
  }
  
  static void dump_event(struct perf_session *session, union perf_event *event,
  		       u64 file_offset, struct perf_sample *sample)
  {
  	if (!dump_trace)
  		return;
  
  	printf("\n%#" PRIx64 " [%#x]: event: %d\n",
  	       file_offset, event->header.size, event->header.type);
  
  	trace_event(event);
  
  	if (sample)
  		perf_session__print_tstamp(session, event, sample);
  
  	printf("%#" PRIx64 " [%#x]: PERF_RECORD_%s", file_offset,
  	       event->header.size, perf_event__name(event->header.type));
  }
  
  static void dump_sample(struct perf_session *session, union perf_event *event,
  			struct perf_sample *sample)
  {
  	if (!dump_trace)
  		return;
  
  	printf("(IP, %d): %d/%d: %#" PRIx64 " period: %" PRIu64 "\n",
  	       event->header.misc, sample->pid, sample->tid, sample->ip,
  	       sample->period);
  
  	if (session->sample_type & PERF_SAMPLE_CALLCHAIN)
  		callchain__printf(sample);
  }
  
  static int perf_session_deliver_event(struct perf_session *session,
  				      union perf_event *event,
  				      struct perf_sample *sample,
  				      struct perf_event_ops *ops,
  				      u64 file_offset)
  {
  	struct perf_evsel *evsel;
  
  	dump_event(session, event, file_offset, sample);
  
  	switch (event->header.type) {
  	case PERF_RECORD_SAMPLE:
  		dump_sample(session, event, sample);
  		evsel = perf_evlist__id2evsel(session->evlist, sample->id);
  		if (evsel == NULL) {
  			++session->hists.stats.nr_unknown_id;
  			return -1;
  		}
  		return ops->sample(event, sample, evsel, session);
  	case PERF_RECORD_MMAP:
  		return ops->mmap(event, sample, session);
  	case PERF_RECORD_COMM:
  		return ops->comm(event, sample, session);
  	case PERF_RECORD_FORK:
  		return ops->fork(event, sample, session);
  	case PERF_RECORD_EXIT:
  		return ops->exit(event, sample, session);
  	case PERF_RECORD_LOST:
  		return ops->lost(event, sample, session);
  	case PERF_RECORD_READ:
  		return ops->read(event, sample, session);
  	case PERF_RECORD_THROTTLE:
  		return ops->throttle(event, sample, session);
  	case PERF_RECORD_UNTHROTTLE:
  		return ops->unthrottle(event, sample, session);
  	default:
  		++session->hists.stats.nr_unknown_events;
  		return -1;
  	}
  }
  
  static int perf_session__preprocess_sample(struct perf_session *session,
  					   union perf_event *event, struct perf_sample *sample)
  {
  	if (event->header.type != PERF_RECORD_SAMPLE ||
  	    !(session->sample_type & PERF_SAMPLE_CALLCHAIN))
  		return 0;
  
  	if (!ip_callchain__valid(sample->callchain, event)) {
  		pr_debug("call-chain problem with event, skipping it.\n");
  		++session->hists.stats.nr_invalid_chains;
  		session->hists.stats.total_invalid_chains += sample->period;
  		return -EINVAL;
  	}
  	return 0;
  }
  
  static int perf_session__process_user_event(struct perf_session *session, union perf_event *event,
  					    struct perf_event_ops *ops, u64 file_offset)
  {
  	dump_event(session, event, file_offset, NULL);
  
  	/* These events are processed right away */
  	switch (event->header.type) {
  	case PERF_RECORD_HEADER_ATTR:
  		return ops->attr(event, session);
  	case PERF_RECORD_HEADER_EVENT_TYPE:
  		return ops->event_type(event, session);
  	case PERF_RECORD_HEADER_TRACING_DATA:
  		/* setup for reading amidst mmap */
  		lseek(session->fd, file_offset, SEEK_SET);
  		return ops->tracing_data(event, session);
  	case PERF_RECORD_HEADER_BUILD_ID:
  		return ops->build_id(event, session);
  	case PERF_RECORD_FINISHED_ROUND:
  		return ops->finished_round(event, session, ops);
  	default:
  		return -EINVAL;
  	}
  }
  
  static int perf_session__process_event(struct perf_session *session,
  				       union perf_event *event,
  				       struct perf_event_ops *ops,
  				       u64 file_offset)
  {
  	struct perf_sample sample;
  	int ret;
  
  	if (session->header.needs_swap &&
  	    perf_event__swap_ops[event->header.type])
  		perf_event__swap_ops[event->header.type](event);
  
  	if (event->header.type >= PERF_RECORD_HEADER_MAX)
  		return -EINVAL;
  
  	hists__inc_nr_events(&session->hists, event->header.type);
  
  	if (event->header.type >= PERF_RECORD_USER_TYPE_START)
  		return perf_session__process_user_event(session, event, ops, file_offset);
  
  	/*
  	 * For all kernel events we get the sample data
  	 */
  	ret = perf_session__parse_sample(session, event, &sample);
  	if (ret)
  		return ret;
  
  	/* Preprocess sample records - precheck callchains */
  	if (perf_session__preprocess_sample(session, event, &sample))
  		return 0;
  
  	if (ops->ordered_samples) {
  		ret = perf_session_queue_event(session, event, &sample,
  					       file_offset);
  		if (ret != -ETIME)
  			return ret;
  	}
  
  	return perf_session_deliver_event(session, event, &sample, ops,
  					  file_offset);
  }
  
  void perf_event_header__bswap(struct perf_event_header *self)
  {
  	self->type = bswap_32(self->type);
  	self->misc = bswap_16(self->misc);
  	self->size = bswap_16(self->size);
  }
  
  static struct thread *perf_session__register_idle_thread(struct perf_session *self)
  {
  	struct thread *thread = perf_session__findnew(self, 0);
  
  	if (thread == NULL || thread__set_comm(thread, "swapper")) {
  		pr_err("problem inserting idle task.\n");
  		thread = NULL;
  	}
  
  	return thread;
  }
  
  static void perf_session__warn_about_errors(const struct perf_session *session,
  					    const struct perf_event_ops *ops)
  {
  	if (ops->lost == perf_event__process_lost &&
  	    session->hists.stats.total_lost != 0) {
  		ui__warning("Processed %" PRIu64 " events and LOST %" PRIu64
  			    "!\n\nCheck IO/CPU overload!\n\n",
  			    session->hists.stats.total_period,
  			    session->hists.stats.total_lost);
  	}
  
  	if (session->hists.stats.nr_unknown_events != 0) {
  		ui__warning("Found %u unknown events!\n\n"
  			    "Is this an older tool processing a perf.data "
  			    "file generated by a more recent tool?\n\n"
  			    "If that is not the case, consider "
  			    "reporting to linux-kernel@vger.kernel.org.\n\n",
  			    session->hists.stats.nr_unknown_events);
  	}
  
  	if (session->hists.stats.nr_unknown_id != 0) {
  		ui__warning("%u samples with id not present in the header\n",
  			    session->hists.stats.nr_unknown_id);
  	}
  
   	if (session->hists.stats.nr_invalid_chains != 0) {
   		ui__warning("Found invalid callchains!\n\n"
   			    "%u out of %u events were discarded for this reason.\n\n"
   			    "Consider reporting to linux-kernel@vger.kernel.org.\n\n",
   			    session->hists.stats.nr_invalid_chains,
   			    session->hists.stats.nr_events[PERF_RECORD_SAMPLE]);
   	}
  }
  
  #define session_done()	(*(volatile int *)(&session_done))
  volatile int session_done;
  
  static int __perf_session__process_pipe_events(struct perf_session *self,
  					       struct perf_event_ops *ops)
  {
  	union perf_event event;
  	uint32_t size;
  	int skip = 0;
  	u64 head;
  	int err;
  	void *p;
  
  	perf_event_ops__fill_defaults(ops);
  
  	head = 0;
  more:
  	err = readn(self->fd, &event, sizeof(struct perf_event_header));
  	if (err <= 0) {
  		if (err == 0)
  			goto done;
  
  		pr_err("failed to read event header\n");
  		goto out_err;
  	}
  
  	if (self->header.needs_swap)
  		perf_event_header__bswap(&event.header);
  
  	size = event.header.size;
  	if (size == 0)
  		size = 8;
  
  	p = &event;
  	p += sizeof(struct perf_event_header);
  
  	if (size - sizeof(struct perf_event_header)) {
  		err = readn(self->fd, p, size - sizeof(struct perf_event_header));
  		if (err <= 0) {
  			if (err == 0) {
  				pr_err("unexpected end of event stream\n");
  				goto done;
  			}
  
  			pr_err("failed to read event data\n");
  			goto out_err;
  		}
  	}
  
  	if (size == 0 ||
  	    (skip = perf_session__process_event(self, &event, ops, head)) < 0) {
  		dump_printf("%#" PRIx64 " [%#x]: skipping unknown header type: %d\n",
  			    head, event.header.size, event.header.type);
  		/*
  		 * assume we lost track of the stream, check alignment, and
  		 * increment a single u64 in the hope to catch on again 'soon'.
  		 */
  		if (unlikely(head & 7))
  			head &= ~7ULL;
  
  		size = 8;
  	}
  
  	head += size;
  
  	if (skip > 0)
  		head += skip;
  
  	if (!session_done())
  		goto more;
  done:
  	err = 0;
  out_err:
  	perf_session__warn_about_errors(self, ops);
  	perf_session_free_sample_buffers(self);
  	return err;
  }
  
  static union perf_event *
  fetch_mmaped_event(struct perf_session *session,
  		   u64 head, size_t mmap_size, char *buf)
  {
  	union perf_event *event;
  
  	/*
  	 * Ensure we have enough space remaining to read
  	 * the size of the event in the headers.
  	 */
  	if (head + sizeof(event->header) > mmap_size)
  		return NULL;
  
  	event = (union perf_event *)(buf + head);
  
  	if (session->header.needs_swap)
  		perf_event_header__bswap(&event->header);
  
  	if (head + event->header.size > mmap_size)
  		return NULL;
  
  	return event;
  }
  
  int __perf_session__process_events(struct perf_session *session,
  				   u64 data_offset, u64 data_size,
  				   u64 file_size, struct perf_event_ops *ops)
  {
  	u64 head, page_offset, file_offset, file_pos, progress_next;
  	int err, mmap_prot, mmap_flags, map_idx = 0;
  	struct ui_progress *progress;
  	size_t	page_size, mmap_size;
  	char *buf, *mmaps[8];
  	union perf_event *event;
  	uint32_t size;
  
  	perf_event_ops__fill_defaults(ops);
  
  	page_size = sysconf(_SC_PAGESIZE);
  
  	page_offset = page_size * (data_offset / page_size);
  	file_offset = page_offset;
  	head = data_offset - page_offset;
  
  	if (data_offset + data_size < file_size)
  		file_size = data_offset + data_size;
  
  	progress_next = file_size / 16;
  	progress = ui_progress__new("Processing events...", file_size);
  	if (progress == NULL)
  		return -1;
  
  	mmap_size = session->mmap_window;
  	if (mmap_size > file_size)
  		mmap_size = file_size;
  
  	memset(mmaps, 0, sizeof(mmaps));
  
  	mmap_prot  = PROT_READ;
  	mmap_flags = MAP_SHARED;
  
  	if (session->header.needs_swap) {
  		mmap_prot  |= PROT_WRITE;
  		mmap_flags = MAP_PRIVATE;
  	}
  remap:
  	buf = mmap(NULL, mmap_size, mmap_prot, mmap_flags, session->fd,
  		   file_offset);
  	if (buf == MAP_FAILED) {
  		pr_err("failed to mmap file\n");
  		err = -errno;
  		goto out_err;
  	}
  	mmaps[map_idx] = buf;
  	map_idx = (map_idx + 1) & (ARRAY_SIZE(mmaps) - 1);
  	file_pos = file_offset + head;
  
  more:
  	event = fetch_mmaped_event(session, head, mmap_size, buf);
  	if (!event) {
  		if (mmaps[map_idx]) {
  			munmap(mmaps[map_idx], mmap_size);
  			mmaps[map_idx] = NULL;
  		}
  
  		page_offset = page_size * (head / page_size);
  		file_offset += page_offset;
  		head -= page_offset;
  		goto remap;
  	}
  
  	size = event->header.size;
  
  	if (size == 0 ||
  	    perf_session__process_event(session, event, ops, file_pos) < 0) {
  		dump_printf("%#" PRIx64 " [%#x]: skipping unknown header type: %d\n",
  			    file_offset + head, event->header.size,
  			    event->header.type);
  		/*
  		 * assume we lost track of the stream, check alignment, and
  		 * increment a single u64 in the hope to catch on again 'soon'.
  		 */
  		if (unlikely(head & 7))
  			head &= ~7ULL;
  
  		size = 8;
  	}
  
  	head += size;
  	file_pos += size;
  
  	if (file_pos >= progress_next) {
  		progress_next += file_size / 16;
  		ui_progress__update(progress, file_pos);
  	}
  
  	if (file_pos < file_size)
  		goto more;
  
  	err = 0;
  	/* do the final flush for ordered samples */
  	session->ordered_samples.next_flush = ULLONG_MAX;
  	flush_sample_queue(session, ops);
  out_err:
  	ui_progress__delete(progress);
  	perf_session__warn_about_errors(session, ops);
  	perf_session_free_sample_buffers(session);
  	return err;
  }
  
  int perf_session__process_events(struct perf_session *self,
  				 struct perf_event_ops *ops)
  {
  	int err;
  
  	if (perf_session__register_idle_thread(self) == NULL)
  		return -ENOMEM;
  
  	if (!self->fd_pipe)
  		err = __perf_session__process_events(self,
  						     self->header.data_offset,
  						     self->header.data_size,
  						     self->size, ops);
  	else
  		err = __perf_session__process_pipe_events(self, ops);
  
  	return err;
  }
  
  bool perf_session__has_traces(struct perf_session *self, const char *msg)
  {
  	if (!(self->sample_type & PERF_SAMPLE_RAW)) {
  		pr_err("No trace sample to read. Did you call 'perf %s'?\n", msg);
  		return false;
  	}
  
  	return true;
  }
  
  int perf_session__set_kallsyms_ref_reloc_sym(struct map **maps,
  					     const char *symbol_name,
  					     u64 addr)
  {
  	char *bracket;
  	enum map_type i;
  	struct ref_reloc_sym *ref;
  
  	ref = zalloc(sizeof(struct ref_reloc_sym));
  	if (ref == NULL)
  		return -ENOMEM;
  
  	ref->name = strdup(symbol_name);
  	if (ref->name == NULL) {
  		free(ref);
  		return -ENOMEM;
  	}
  
  	bracket = strchr(ref->name, ']');
  	if (bracket)
  		*bracket = '\0';
  
  	ref->addr = addr;
  
  	for (i = 0; i < MAP__NR_TYPES; ++i) {
  		struct kmap *kmap = map__kmap(maps[i]);
  		kmap->ref_reloc_sym = ref;
  	}
  
  	return 0;
  }
  
  size_t perf_session__fprintf_dsos(struct perf_session *self, FILE *fp)
  {
  	return __dsos__fprintf(&self->host_machine.kernel_dsos, fp) +
  	       __dsos__fprintf(&self->host_machine.user_dsos, fp) +
  	       machines__fprintf_dsos(&self->machines, fp);
  }
  
  size_t perf_session__fprintf_dsos_buildid(struct perf_session *self, FILE *fp,
  					  bool with_hits)
  {
  	size_t ret = machine__fprintf_dsos_buildid(&self->host_machine, fp, with_hits);
  	return ret + machines__fprintf_dsos_buildid(&self->machines, fp, with_hits);
  }
  
  size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp)
  {
  	struct perf_evsel *pos;
  	size_t ret = fprintf(fp, "Aggregated stats:\n");
  
  	ret += hists__fprintf_nr_events(&session->hists, fp);
  
  	list_for_each_entry(pos, &session->evlist->entries, node) {
  		ret += fprintf(fp, "%s stats:\n", event_name(pos));
  		ret += hists__fprintf_nr_events(&pos->hists, fp);
  	}
  
  	return ret;
  }
  
  struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
  					      unsigned int type)
  {
  	struct perf_evsel *pos;
  
  	list_for_each_entry(pos, &session->evlist->entries, node) {
  		if (pos->attr.type == type)
  			return pos;
  	}
  	return NULL;
  }
  
  void perf_session__print_symbols(union perf_event *event,
  				struct perf_sample *sample,
  				struct perf_session *session)
  {
  	struct addr_location al;
  	const char *symname, *dsoname;
  	struct callchain_cursor *cursor = &session->callchain_cursor;
  	struct callchain_cursor_node *node;
  
  	if (perf_event__preprocess_sample(event, session, &al, sample,
  					  NULL) < 0) {
  		error("problem processing %d event, skipping it.\n",
  			event->header.type);
  		return;
  	}
  
  	if (symbol_conf.use_callchain && sample->callchain) {
  
  		if (perf_session__resolve_callchain(session, al.thread,
  						sample->callchain, NULL) != 0) {
  			if (verbose)
  				error("Failed to resolve callchain. Skipping\n");
  			return;
  		}
  		callchain_cursor_commit(cursor);
  
  		while (1) {
  			node = callchain_cursor_current(cursor);
  			if (!node)
  				break;
  
  			if (node->sym && node->sym->name)
  				symname = node->sym->name;
  			else
  				symname = "";
  
  			if (node->map && node->map->dso && node->map->dso->name)
  				dsoname = node->map->dso->name;
  			else
  				dsoname = "";
  
  			printf("\t%16" PRIx64 " %s (%s)\n", node->ip, symname, dsoname);
  
  			callchain_cursor_advance(cursor);
  		}
  
  	} else {
  		if (al.sym && al.sym->name)
  			symname = al.sym->name;
  		else
  			symname = "";
  
  		if (al.map && al.map->dso && al.map->dso->name)
  			dsoname = al.map->dso->name;
  		else
  			dsoname = "";
  
  		printf("%16" PRIx64 " %s (%s)", al.addr, symname, dsoname);
  	}
  }
  