#include "callchain.h"

  #include "debug.h"
  #include "event.h"

  #include "evsel.h"
  #include "hist.h"

  #include "machine.h"
  #include "map.h"

  #include "sort.h"

  #include "strlist.h"

  #include "thread.h"

  #include "vdso.h"

  #include <stdbool.h>

  #include <symbol/kallsyms.h>

  #include "unwind.h"

  #include "linux/hash.h"

  static void dsos__init(struct dsos *dsos)
  {
  	INIT_LIST_HEAD(&dsos->head);
  	dsos->root = RB_ROOT;
  }

  int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
  {

  	map_groups__init(&machine->kmaps, machine);

  	RB_CLEAR_NODE(&machine->rb_node);

  	dsos__init(&machine->user_dsos);
  	dsos__init(&machine->kernel_dsos);

  
  	machine->threads = RB_ROOT;
  	INIT_LIST_HEAD(&machine->dead_threads);
  	machine->last_match = NULL;

  	machine->vdso_info = NULL;

  	machine->pid = pid;

  	machine->symbol_filter = NULL;

  	machine->id_hdr_size = 0;

  	machine->comm_exec = false;

  	machine->kernel_start = 0;

  	machine->root_dir = strdup(root_dir);
  	if (machine->root_dir == NULL)
  		return -ENOMEM;
  
  	if (pid != HOST_KERNEL_ID) {

  		struct thread *thread = machine__findnew_thread(machine, -1,

  								pid);

  		char comm[64];
  
  		if (thread == NULL)
  			return -ENOMEM;
  
  		snprintf(comm, sizeof(comm), "[guest/%d]", pid);

  		thread__set_comm(thread, comm, 0);

  	}

  	machine->current_tid = NULL;

  	return 0;
  }

  struct machine *machine__new_host(void)
  {
  	struct machine *machine = malloc(sizeof(*machine));
  
  	if (machine != NULL) {
  		machine__init(machine, "", HOST_KERNEL_ID);
  
  		if (machine__create_kernel_maps(machine) < 0)
  			goto out_delete;
  	}
  
  	return machine;
  out_delete:
  	free(machine);
  	return NULL;
  }

  static void dsos__delete(struct dsos *dsos)

  {
  	struct dso *pos, *n;

  	list_for_each_entry_safe(pos, n, &dsos->head, node) {

  		RB_CLEAR_NODE(&pos->rb_node);

  		list_del(&pos->node);
  		dso__delete(pos);
  	}
  }

  void machine__delete_dead_threads(struct machine *machine)
  {
  	struct thread *n, *t;
  
  	list_for_each_entry_safe(t, n, &machine->dead_threads, node) {
  		list_del(&t->node);
  		thread__delete(t);
  	}
  }
  
  void machine__delete_threads(struct machine *machine)
  {
  	struct rb_node *nd = rb_first(&machine->threads);
  
  	while (nd) {
  		struct thread *t = rb_entry(nd, struct thread, rb_node);
  
  		rb_erase(&t->rb_node, &machine->threads);
  		nd = rb_next(nd);
  		thread__delete(t);
  	}
  }

  void machine__exit(struct machine *machine)
  {
  	map_groups__exit(&machine->kmaps);
  	dsos__delete(&machine->user_dsos);
  	dsos__delete(&machine->kernel_dsos);

  	vdso__exit(machine);

  	zfree(&machine->root_dir);

  	zfree(&machine->current_tid);

  }
  
  void machine__delete(struct machine *machine)
  {
  	machine__exit(machine);
  	free(machine);
  }

  void machines__init(struct machines *machines)
  {
  	machine__init(&machines->host, "", HOST_KERNEL_ID);
  	machines->guests = RB_ROOT;

  	machines->symbol_filter = NULL;

  }
  
  void machines__exit(struct machines *machines)
  {
  	machine__exit(&machines->host);
  	/* XXX exit guest */
  }
  
  struct machine *machines__add(struct machines *machines, pid_t pid,

  			      const char *root_dir)
  {

  	struct rb_node **p = &machines->guests.rb_node;

  	struct rb_node *parent = NULL;
  	struct machine *pos, *machine = malloc(sizeof(*machine));
  
  	if (machine == NULL)
  		return NULL;
  
  	if (machine__init(machine, root_dir, pid) != 0) {
  		free(machine);
  		return NULL;
  	}

  	machine->symbol_filter = machines->symbol_filter;

  	while (*p != NULL) {
  		parent = *p;
  		pos = rb_entry(parent, struct machine, rb_node);
  		if (pid < pos->pid)
  			p = &(*p)->rb_left;
  		else
  			p = &(*p)->rb_right;
  	}
  
  	rb_link_node(&machine->rb_node, parent, p);

  	rb_insert_color(&machine->rb_node, &machines->guests);

  
  	return machine;
  }

  void machines__set_symbol_filter(struct machines *machines,
  				 symbol_filter_t symbol_filter)
  {
  	struct rb_node *nd;
  
  	machines->symbol_filter = symbol_filter;
  	machines->host.symbol_filter = symbol_filter;
  
  	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
  		struct machine *machine = rb_entry(nd, struct machine, rb_node);
  
  		machine->symbol_filter = symbol_filter;
  	}
  }

  void machines__set_comm_exec(struct machines *machines, bool comm_exec)
  {
  	struct rb_node *nd;
  
  	machines->host.comm_exec = comm_exec;
  
  	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
  		struct machine *machine = rb_entry(nd, struct machine, rb_node);
  
  		machine->comm_exec = comm_exec;
  	}
  }

  struct machine *machines__find(struct machines *machines, pid_t pid)

  {

  	struct rb_node **p = &machines->guests.rb_node;

  	struct rb_node *parent = NULL;
  	struct machine *machine;
  	struct machine *default_machine = NULL;

  	if (pid == HOST_KERNEL_ID)
  		return &machines->host;

  	while (*p != NULL) {
  		parent = *p;
  		machine = rb_entry(parent, struct machine, rb_node);
  		if (pid < machine->pid)
  			p = &(*p)->rb_left;
  		else if (pid > machine->pid)
  			p = &(*p)->rb_right;
  		else
  			return machine;
  		if (!machine->pid)
  			default_machine = machine;
  	}
  
  	return default_machine;
  }

  struct machine *machines__findnew(struct machines *machines, pid_t pid)

  {
  	char path[PATH_MAX];
  	const char *root_dir = "";
  	struct machine *machine = machines__find(machines, pid);
  
  	if (machine && (machine->pid == pid))
  		goto out;
  
  	if ((pid != HOST_KERNEL_ID) &&
  	    (pid != DEFAULT_GUEST_KERNEL_ID) &&
  	    (symbol_conf.guestmount)) {
  		sprintf(path, "%s/%d", symbol_conf.guestmount, pid);
  		if (access(path, R_OK)) {
  			static struct strlist *seen;
  
  			if (!seen)
  				seen = strlist__new(true, NULL);
  
  			if (!strlist__has_entry(seen, path)) {
  				pr_err("Can't access file %s
  ", path);
  				strlist__add(seen, path);
  			}
  			machine = NULL;
  			goto out;
  		}
  		root_dir = path;
  	}
  
  	machine = machines__add(machines, pid, root_dir);
  out:
  	return machine;
  }

  void machines__process_guests(struct machines *machines,
  			      machine__process_t process, void *data)

  {
  	struct rb_node *nd;

  	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {

  		struct machine *pos = rb_entry(nd, struct machine, rb_node);
  		process(pos, data);
  	}
  }
  
  char *machine__mmap_name(struct machine *machine, char *bf, size_t size)
  {
  	if (machine__is_host(machine))
  		snprintf(bf, size, "[%s]", "kernel.kallsyms");
  	else if (machine__is_default_guest(machine))
  		snprintf(bf, size, "[%s]", "guest.kernel.kallsyms");
  	else {
  		snprintf(bf, size, "[%s.%d]", "guest.kernel.kallsyms",
  			 machine->pid);
  	}
  
  	return bf;
  }

  void machines__set_id_hdr_size(struct machines *machines, u16 id_hdr_size)

  {
  	struct rb_node *node;
  	struct machine *machine;

  	machines->host.id_hdr_size = id_hdr_size;
  
  	for (node = rb_first(&machines->guests); node; node = rb_next(node)) {

  		machine = rb_entry(node, struct machine, rb_node);
  		machine->id_hdr_size = id_hdr_size;
  	}
  
  	return;
  }

  static void machine__update_thread_pid(struct machine *machine,
  				       struct thread *th, pid_t pid)
  {
  	struct thread *leader;
  
  	if (pid == th->pid_ || pid == -1 || th->pid_ != -1)
  		return;
  
  	th->pid_ = pid;
  
  	if (th->pid_ == th->tid)
  		return;
  
  	leader = machine__findnew_thread(machine, th->pid_, th->pid_);
  	if (!leader)
  		goto out_err;
  
  	if (!leader->mg)

  		leader->mg = map_groups__new(machine);

  
  	if (!leader->mg)
  		goto out_err;
  
  	if (th->mg == leader->mg)
  		return;
  
  	if (th->mg) {
  		/*
  		 * Maps are created from MMAP events which provide the pid and
  		 * tid.  Consequently there never should be any maps on a thread
  		 * with an unknown pid.  Just print an error if there are.
  		 */
  		if (!map_groups__empty(th->mg))
  			pr_err("Discarding thread maps for %d:%d
  ",
  			       th->pid_, th->tid);
  		map_groups__delete(th->mg);
  	}
  
  	th->mg = map_groups__get(leader->mg);
  
  	return;
  
  out_err:
  	pr_err("Failed to join map groups for %d:%d
  ", th->pid_, th->tid);
  }

  static struct thread *__machine__findnew_thread(struct machine *machine,
  						pid_t pid, pid_t tid,

  						bool create)
  {
  	struct rb_node **p = &machine->threads.rb_node;
  	struct rb_node *parent = NULL;
  	struct thread *th;
  
  	/*

  	 * Front-end cache - TID lookups come in blocks,

  	 * so most of the time we dont have to look up
  	 * the full rbtree:
  	 */

  	th = machine->last_match;
  	if (th && th->tid == tid) {
  		machine__update_thread_pid(machine, th, pid);
  		return th;

  	}

  
  	while (*p != NULL) {
  		parent = *p;
  		th = rb_entry(parent, struct thread, rb_node);

  		if (th->tid == tid) {

  			machine->last_match = th;

  			machine__update_thread_pid(machine, th, pid);

  			return th;
  		}

  		if (tid < th->tid)

  			p = &(*p)->rb_left;
  		else
  			p = &(*p)->rb_right;
  	}
  
  	if (!create)
  		return NULL;

  	th = thread__new(pid, tid);

  	if (th != NULL) {
  		rb_link_node(&th->rb_node, parent, p);
  		rb_insert_color(&th->rb_node, &machine->threads);

  
  		/*
  		 * We have to initialize map_groups separately
  		 * after rb tree is updated.
  		 *
  		 * The reason is that we call machine__findnew_thread
  		 * within thread__init_map_groups to find the thread
  		 * leader and that would screwed the rb tree.
  		 */

  		if (thread__init_map_groups(th, machine)) {

  			rb_erase(&th->rb_node, &machine->threads);

  			thread__delete(th);

  			return NULL;

  		}

  
  		machine->last_match = th;

  	}
  
  	return th;
  }

  struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
  				       pid_t tid)

  {

  	return __machine__findnew_thread(machine, pid, tid, true);

  }

  struct thread *machine__find_thread(struct machine *machine, pid_t pid,
  				    pid_t tid)

  {

  	return __machine__findnew_thread(machine, pid, tid, false);

  }

  struct comm *machine__thread_exec_comm(struct machine *machine,
  				       struct thread *thread)
  {
  	if (machine->comm_exec)
  		return thread__exec_comm(thread);
  	else
  		return thread__comm(thread);
  }

  int machine__process_comm_event(struct machine *machine, union perf_event *event,
  				struct perf_sample *sample)

  {

  	struct thread *thread = machine__findnew_thread(machine,
  							event->comm.pid,
  							event->comm.tid);

  	bool exec = event->header.misc & PERF_RECORD_MISC_COMM_EXEC;

  	if (exec)
  		machine->comm_exec = true;

  	if (dump_trace)
  		perf_event__fprintf_comm(event, stdout);

  	if (thread == NULL ||
  	    __thread__set_comm(thread, event->comm.comm, sample->time, exec)) {

  		dump_printf("problem processing PERF_RECORD_COMM, skipping event.
  ");
  		return -1;
  	}
  
  	return 0;
  }
  
  int machine__process_lost_event(struct machine *machine __maybe_unused,

  				union perf_event *event, struct perf_sample *sample __maybe_unused)

  {
  	dump_printf(": id:%" PRIu64 ": lost:%" PRIu64 "
  ",
  		    event->lost.id, event->lost.lost);
  	return 0;
  }

  struct map *machine__new_module(struct machine *machine, u64 start,
  				const char *filename)
  {
  	struct map *map;
  	struct dso *dso = __dsos__findnew(&machine->kernel_dsos, filename);

  	bool compressed;

  
  	if (dso == NULL)
  		return NULL;
  
  	map = map__new2(start, dso, MAP__FUNCTION);
  	if (map == NULL)
  		return NULL;
  
  	if (machine__is_host(machine))
  		dso->symtab_type = DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE;
  	else
  		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KMODULE;

  
  	/* _KMODULE_COMP should be next to _KMODULE */
  	if (is_kernel_module(filename, &compressed) && compressed)
  		dso->symtab_type++;

  	map_groups__insert(&machine->kmaps, map);
  	return map;
  }

  size_t machines__fprintf_dsos(struct machines *machines, FILE *fp)

  {
  	struct rb_node *nd;

  	size_t ret = __dsos__fprintf(&machines->host.kernel_dsos.head, fp) +
  		     __dsos__fprintf(&machines->host.user_dsos.head, fp);

  	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {

  		struct machine *pos = rb_entry(nd, struct machine, rb_node);

  		ret += __dsos__fprintf(&pos->kernel_dsos.head, fp);
  		ret += __dsos__fprintf(&pos->user_dsos.head, fp);

  	}
  
  	return ret;
  }

  size_t machine__fprintf_dsos_buildid(struct machine *m, FILE *fp,

  				     bool (skip)(struct dso *dso, int parm), int parm)
  {

  	return __dsos__fprintf_buildid(&m->kernel_dsos.head, fp, skip, parm) +
  	       __dsos__fprintf_buildid(&m->user_dsos.head, fp, skip, parm);

  }

  size_t machines__fprintf_dsos_buildid(struct machines *machines, FILE *fp,

  				     bool (skip)(struct dso *dso, int parm), int parm)
  {
  	struct rb_node *nd;

  	size_t ret = machine__fprintf_dsos_buildid(&machines->host, fp, skip, parm);

  	for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {

  		struct machine *pos = rb_entry(nd, struct machine, rb_node);
  		ret += machine__fprintf_dsos_buildid(pos, fp, skip, parm);
  	}
  	return ret;
  }
  
  size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
  {
  	int i;
  	size_t printed = 0;
  	struct dso *kdso = machine->vmlinux_maps[MAP__FUNCTION]->dso;
  
  	if (kdso->has_build_id) {
  		char filename[PATH_MAX];
  		if (dso__build_id_filename(kdso, filename, sizeof(filename)))
  			printed += fprintf(fp, "[0] %s
  ", filename);
  	}
  
  	for (i = 0; i < vmlinux_path__nr_entries; ++i)
  		printed += fprintf(fp, "[%d] %s
  ",
  				   i + kdso->has_build_id, vmlinux_path[i]);
  
  	return printed;
  }
  
  size_t machine__fprintf(struct machine *machine, FILE *fp)
  {
  	size_t ret = 0;
  	struct rb_node *nd;
  
  	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
  		struct thread *pos = rb_entry(nd, struct thread, rb_node);
  
  		ret += thread__fprintf(pos, fp);
  	}
  
  	return ret;
  }
  
  static struct dso *machine__get_kernel(struct machine *machine)
  {
  	const char *vmlinux_name = NULL;
  	struct dso *kernel;
  
  	if (machine__is_host(machine)) {
  		vmlinux_name = symbol_conf.vmlinux_name;
  		if (!vmlinux_name)
  			vmlinux_name = "[kernel.kallsyms]";
  
  		kernel = dso__kernel_findnew(machine, vmlinux_name,
  					     "[kernel]",
  					     DSO_TYPE_KERNEL);
  	} else {
  		char bf[PATH_MAX];
  
  		if (machine__is_default_guest(machine))
  			vmlinux_name = symbol_conf.default_guest_vmlinux_name;
  		if (!vmlinux_name)
  			vmlinux_name = machine__mmap_name(machine, bf,
  							  sizeof(bf));
  
  		kernel = dso__kernel_findnew(machine, vmlinux_name,
  					     "[guest.kernel]",
  					     DSO_TYPE_GUEST_KERNEL);
  	}
  
  	if (kernel != NULL && (!kernel->has_build_id))
  		dso__read_running_kernel_build_id(kernel, machine);
  
  	return kernel;
  }
  
  struct process_args {
  	u64 start;
  };

  static void machine__get_kallsyms_filename(struct machine *machine, char *buf,
  					   size_t bufsz)
  {
  	if (machine__is_default_guest(machine))
  		scnprintf(buf, bufsz, "%s", symbol_conf.default_guest_kallsyms);
  	else
  		scnprintf(buf, bufsz, "%s/proc/kallsyms", machine->root_dir);
  }

  const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
  
  /* Figure out the start address of kernel map from /proc/kallsyms.
   * Returns the name of the start symbol in *symbol_name. Pass in NULL as
   * symbol_name if it's not that important.
   */

  static u64 machine__get_running_kernel_start(struct machine *machine,
  					     const char **symbol_name)

  {

  	char filename[PATH_MAX];

  	int i;
  	const char *name;
  	u64 addr = 0;

  	machine__get_kallsyms_filename(machine, filename, PATH_MAX);

  
  	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
  		return 0;

  	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
  		addr = kallsyms__get_function_start(filename, name);
  		if (addr)
  			break;
  	}
  
  	if (symbol_name)
  		*symbol_name = name;

  	return addr;

  }
  
  int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
  {
  	enum map_type type;

  	u64 start = machine__get_running_kernel_start(machine, NULL);

  
  	for (type = 0; type < MAP__NR_TYPES; ++type) {
  		struct kmap *kmap;
  
  		machine->vmlinux_maps[type] = map__new2(start, kernel, type);
  		if (machine->vmlinux_maps[type] == NULL)
  			return -1;
  
  		machine->vmlinux_maps[type]->map_ip =
  			machine->vmlinux_maps[type]->unmap_ip =
  				identity__map_ip;
  		kmap = map__kmap(machine->vmlinux_maps[type]);
  		kmap->kmaps = &machine->kmaps;
  		map_groups__insert(&machine->kmaps,
  				   machine->vmlinux_maps[type]);
  	}
  
  	return 0;
  }
  
  void machine__destroy_kernel_maps(struct machine *machine)
  {
  	enum map_type type;
  
  	for (type = 0; type < MAP__NR_TYPES; ++type) {
  		struct kmap *kmap;
  
  		if (machine->vmlinux_maps[type] == NULL)
  			continue;
  
  		kmap = map__kmap(machine->vmlinux_maps[type]);
  		map_groups__remove(&machine->kmaps,
  				   machine->vmlinux_maps[type]);
  		if (kmap->ref_reloc_sym) {
  			/*
  			 * ref_reloc_sym is shared among all maps, so free just
  			 * on one of them.
  			 */
  			if (type == MAP__FUNCTION) {

  				zfree((char **)&kmap->ref_reloc_sym->name);
  				zfree(&kmap->ref_reloc_sym);
  			} else
  				kmap->ref_reloc_sym = NULL;

  		}
  
  		map__delete(machine->vmlinux_maps[type]);
  		machine->vmlinux_maps[type] = NULL;
  	}
  }

  int machines__create_guest_kernel_maps(struct machines *machines)

  {
  	int ret = 0;
  	struct dirent **namelist = NULL;
  	int i, items = 0;
  	char path[PATH_MAX];
  	pid_t pid;
  	char *endp;
  
  	if (symbol_conf.default_guest_vmlinux_name ||
  	    symbol_conf.default_guest_modules ||
  	    symbol_conf.default_guest_kallsyms) {
  		machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID);
  	}
  
  	if (symbol_conf.guestmount) {
  		items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
  		if (items <= 0)
  			return -ENOENT;
  		for (i = 0; i < items; i++) {
  			if (!isdigit(namelist[i]->d_name[0])) {
  				/* Filter out . and .. */
  				continue;
  			}
  			pid = (pid_t)strtol(namelist[i]->d_name, &endp, 10);
  			if ((*endp != '\0') ||
  			    (endp == namelist[i]->d_name) ||
  			    (errno == ERANGE)) {
  				pr_debug("invalid directory (%s). Skipping.
  ",
  					 namelist[i]->d_name);
  				continue;
  			}
  			sprintf(path, "%s/%s/proc/kallsyms",
  				symbol_conf.guestmount,
  				namelist[i]->d_name);
  			ret = access(path, R_OK);
  			if (ret) {
  				pr_debug("Can't access file %s
  ", path);
  				goto failure;
  			}
  			machines__create_kernel_maps(machines, pid);
  		}
  failure:
  		free(namelist);
  	}
  
  	return ret;
  }

  void machines__destroy_kernel_maps(struct machines *machines)

  {

  	struct rb_node *next = rb_first(&machines->guests);
  
  	machine__destroy_kernel_maps(&machines->host);

  
  	while (next) {
  		struct machine *pos = rb_entry(next, struct machine, rb_node);
  
  		next = rb_next(&pos->rb_node);

  		rb_erase(&pos->rb_node, &machines->guests);

  		machine__delete(pos);
  	}
  }

  int machines__create_kernel_maps(struct machines *machines, pid_t pid)

  {
  	struct machine *machine = machines__findnew(machines, pid);
  
  	if (machine == NULL)
  		return -1;
  
  	return machine__create_kernel_maps(machine);
  }
  
  int machine__load_kallsyms(struct machine *machine, const char *filename,
  			   enum map_type type, symbol_filter_t filter)
  {
  	struct map *map = machine->vmlinux_maps[type];
  	int ret = dso__load_kallsyms(map->dso, filename, map, filter);
  
  	if (ret > 0) {
  		dso__set_loaded(map->dso, type);
  		/*
  		 * Since /proc/kallsyms will have multiple sessions for the
  		 * kernel, with modules between them, fixup the end of all
  		 * sections.
  		 */
  		__map_groups__fixup_end(&machine->kmaps, type);
  	}
  
  	return ret;
  }
  
  int machine__load_vmlinux_path(struct machine *machine, enum map_type type,
  			       symbol_filter_t filter)
  {
  	struct map *map = machine->vmlinux_maps[type];
  	int ret = dso__load_vmlinux_path(map->dso, map, filter);

  	if (ret > 0)

  		dso__set_loaded(map->dso, type);

  
  	return ret;
  }
  
  static void map_groups__fixup_end(struct map_groups *mg)
  {
  	int i;
  	for (i = 0; i < MAP__NR_TYPES; ++i)
  		__map_groups__fixup_end(mg, i);
  }
  
  static char *get_kernel_version(const char *root_dir)
  {
  	char version[PATH_MAX];
  	FILE *file;
  	char *name, *tmp;
  	const char *prefix = "Linux version ";
  
  	sprintf(version, "%s/proc/version", root_dir);
  	file = fopen(version, "r");
  	if (!file)
  		return NULL;
  
  	version[0] = '\0';
  	tmp = fgets(version, sizeof(version), file);
  	fclose(file);
  
  	name = strstr(version, prefix);
  	if (!name)
  		return NULL;
  	name += strlen(prefix);
  	tmp = strchr(name, ' ');
  	if (tmp)
  		*tmp = '\0';
  
  	return strdup(name);
  }
  
  static int map_groups__set_modules_path_dir(struct map_groups *mg,

  				const char *dir_name, int depth)

  {
  	struct dirent *dent;
  	DIR *dir = opendir(dir_name);
  	int ret = 0;
  
  	if (!dir) {
  		pr_debug("%s: cannot open %s dir
  ", __func__, dir_name);
  		return -1;
  	}
  
  	while ((dent = readdir(dir)) != NULL) {
  		char path[PATH_MAX];
  		struct stat st;
  
  		/*sshfs might return bad dent->d_type, so we have to stat*/
  		snprintf(path, sizeof(path), "%s/%s", dir_name, dent->d_name);
  		if (stat(path, &st))
  			continue;
  
  		if (S_ISDIR(st.st_mode)) {
  			if (!strcmp(dent->d_name, ".") ||
  			    !strcmp(dent->d_name, ".."))
  				continue;

  			/* Do not follow top-level source and build symlinks */
  			if (depth == 0) {
  				if (!strcmp(dent->d_name, "source") ||
  				    !strcmp(dent->d_name, "build"))
  					continue;
  			}
  
  			ret = map_groups__set_modules_path_dir(mg, path,
  							       depth + 1);

  			if (ret < 0)
  				goto out;
  		} else {
  			char *dot = strrchr(dent->d_name, '.'),
  			     dso_name[PATH_MAX];
  			struct map *map;
  			char *long_name;

  			if (dot == NULL)

  				continue;

  
  			/* On some system, modules are compressed like .ko.gz */
  			if (is_supported_compression(dot + 1) &&
  			    is_kmodule_extension(dot - 2))
  				dot -= 3;

  			snprintf(dso_name, sizeof(dso_name), "[%.*s]",
  				 (int)(dot - dent->d_name), dent->d_name);
  
  			strxfrchar(dso_name, '-', '_');
  			map = map_groups__find_by_name(mg, MAP__FUNCTION,
  						       dso_name);
  			if (map == NULL)
  				continue;
  
  			long_name = strdup(path);
  			if (long_name == NULL) {
  				ret = -1;
  				goto out;
  			}

  			dso__set_long_name(map->dso, long_name, true);

  			dso__kernel_module_get_build_id(map->dso, "");
  		}
  	}
  
  out:
  	closedir(dir);
  	return ret;
  }
  
  static int machine__set_modules_path(struct machine *machine)
  {
  	char *version;
  	char modules_path[PATH_MAX];
  
  	version = get_kernel_version(machine->root_dir);
  	if (!version)
  		return -1;

  	snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s",

  		 machine->root_dir, version);
  	free(version);

  	return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, 0);

  }

  static int machine__create_module(void *arg, const char *name, u64 start)

  {

  	struct machine *machine = arg;

  	struct map *map;

  
  	map = machine__new_module(machine, start, name);
  	if (map == NULL)
  		return -1;
  
  	dso__kernel_module_get_build_id(map->dso, machine->root_dir);
  
  	return 0;
  }
  
  static int machine__create_modules(struct machine *machine)
  {

  	const char *modules;
  	char path[PATH_MAX];

  	if (machine__is_default_guest(machine)) {

  		modules = symbol_conf.default_guest_modules;

  	} else {
  		snprintf(path, PATH_MAX, "%s/proc/modules", machine->root_dir);

  		modules = path;
  	}

  	if (symbol__restricted_filename(modules, "/proc/modules"))

  		return -1;

  	if (modules__parse(modules, machine, machine__create_module))

  		return -1;

  	if (!machine__set_modules_path(machine))
  		return 0;

  	pr_debug("Problems setting modules path maps, continuing anyway...
  ");

  	return 0;

  }
  
  int machine__create_kernel_maps(struct machine *machine)
  {
  	struct dso *kernel = machine__get_kernel(machine);

  	const char *name;

  	u64 addr = machine__get_running_kernel_start(machine, &name);

  	if (!addr)
  		return -1;

  
  	if (kernel == NULL ||
  	    __machine__create_kernel_maps(machine, kernel) < 0)
  		return -1;
  
  	if (symbol_conf.use_modules && machine__create_modules(machine) < 0) {
  		if (machine__is_host(machine))
  			pr_debug("Problems creating module maps, "
  				 "continuing anyway...
  ");
  		else
  			pr_debug("Problems creating module maps for guest %d, "
  				 "continuing anyway...
  ", machine->pid);
  	}
  
  	/*
  	 * Now that we have all the maps created, just set the ->end of them:
  	 */
  	map_groups__fixup_end(&machine->kmaps);

  
  	if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name,
  					     addr)) {
  		machine__destroy_kernel_maps(machine);
  		return -1;
  	}

  	return 0;
  }

  static void machine__set_kernel_mmap_len(struct machine *machine,
  					 union perf_event *event)
  {

  	int i;
  
  	for (i = 0; i < MAP__NR_TYPES; i++) {
  		machine->vmlinux_maps[i]->start = event->mmap.start;
  		machine->vmlinux_maps[i]->end   = (event->mmap.start +
  						   event->mmap.len);
  		/*
  		 * Be a bit paranoid here, some perf.data file came with
  		 * a zero sized synthesized MMAP event for the kernel.
  		 */
  		if (machine->vmlinux_maps[i]->end == 0)
  			machine->vmlinux_maps[i]->end = ~0ULL;
  	}

  }

  static bool machine__uses_kcore(struct machine *machine)
  {
  	struct dso *dso;

  	list_for_each_entry(dso, &machine->kernel_dsos.head, node) {

  		if (dso__is_kcore(dso))
  			return true;
  	}
  
  	return false;
  }

  static int machine__process_kernel_mmap_event(struct machine *machine,
  					      union perf_event *event)
  {
  	struct map *map;
  	char kmmap_prefix[PATH_MAX];
  	enum dso_kernel_type kernel_type;
  	bool is_kernel_mmap;

  	/* If we have maps from kcore then we do not need or want any others */
  	if (machine__uses_kcore(machine))
  		return 0;

  	machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
  	if (machine__is_host(machine))
  		kernel_type = DSO_TYPE_KERNEL;
  	else
  		kernel_type = DSO_TYPE_GUEST_KERNEL;
  
  	is_kernel_mmap = memcmp(event->mmap.filename,
  				kmmap_prefix,
  				strlen(kmmap_prefix) - 1) == 0;
  	if (event->mmap.filename[0] == '/' ||
  	    (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
  
  		char short_module_name[1024];
  		char *name, *dot;
  
  		if (event->mmap.filename[0] == '/') {
  			name = strrchr(event->mmap.filename, '/');
  			if (name == NULL)
  				goto out_problem;
  
  			++name; /* skip / */
  			dot = strrchr(name, '.');
  			if (dot == NULL)
  				goto out_problem;

  			/* On some system, modules are compressed like .ko.gz */
  			if (is_supported_compression(dot + 1))
  				dot -= 3;
  			if (!is_kmodule_extension(dot + 1))
  				goto out_problem;

  			snprintf(short_module_name, sizeof(short_module_name),
  					"[%.*s]", (int)(dot - name), name);
  			strxfrchar(short_module_name, '-', '_');
  		} else
  			strcpy(short_module_name, event->mmap.filename);
  
  		map = machine__new_module(machine, event->mmap.start,
  					  event->mmap.filename);
  		if (map == NULL)
  			goto out_problem;
  
  		name = strdup(short_module_name);
  		if (name == NULL)
  			goto out_problem;

  		dso__set_short_name(map->dso, name, true);

  		map->end = map->start + event->mmap.len;
  	} else if (is_kernel_mmap) {
  		const char *symbol_name = (event->mmap.filename +
  				strlen(kmmap_prefix));
  		/*
  		 * Should be there already, from the build-id table in
  		 * the header.
  		 */

  		struct dso *kernel = NULL;
  		struct dso *dso;
  
  		list_for_each_entry(dso, &machine->kernel_dsos.head, node) {
  			if (is_kernel_module(dso->long_name, NULL))
  				continue;
  
  			kernel = dso;
  			break;
  		}
  
  		if (kernel == NULL)
  			kernel = __dsos__findnew(&machine->kernel_dsos,
  						 kmmap_prefix);

  		if (kernel == NULL)
  			goto out_problem;
  
  		kernel->kernel = kernel_type;
  		if (__machine__create_kernel_maps(machine, kernel) < 0)
  			goto out_problem;

  		if (strstr(kernel->long_name, "vmlinux"))
  			dso__set_short_name(kernel, "[kernel.vmlinux]", false);

  		machine__set_kernel_mmap_len(machine, event);
  
  		/*
  		 * Avoid using a zero address (kptr_restrict) for the ref reloc
  		 * symbol. Effectively having zero here means that at record
  		 * time /proc/sys/kernel/kptr_restrict was non zero.
  		 */
  		if (event->mmap.pgoff != 0) {
  			maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps,
  							 symbol_name,
  							 event->mmap.pgoff);
  		}
  
  		if (machine__is_default_guest(machine)) {
  			/*
  			 * preload dso of guest kernel and modules
  			 */
  			dso__load(kernel, machine->vmlinux_maps[MAP__FUNCTION],
  				  NULL);
  		}
  	}
  	return 0;
  out_problem:
  	return -1;
  }

  int machine__process_mmap2_event(struct machine *machine,

  				 union perf_event *event,
  				 struct perf_sample *sample __maybe_unused)

  {
  	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
  	struct thread *thread;
  	struct map *map;
  	enum map_type type;
  	int ret = 0;
  
  	if (dump_trace)
  		perf_event__fprintf_mmap2(event, stdout);
  
  	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
  	    cpumode == PERF_RECORD_MISC_KERNEL) {
  		ret = machine__process_kernel_mmap_event(machine, event);
  		if (ret < 0)
  			goto out_problem;
  		return 0;
  	}
  
  	thread = machine__findnew_thread(machine, event->mmap2.pid,

  					event->mmap2.tid);

  	if (thread == NULL)
  		goto out_problem;
  
  	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
  		type = MAP__VARIABLE;
  	else
  		type = MAP__FUNCTION;

  	map = map__new(machine, event->mmap2.start,

  			event->mmap2.len, event->mmap2.pgoff,
  			event->mmap2.pid, event->mmap2.maj,
  			event->mmap2.min, event->mmap2.ino,
  			event->mmap2.ino_generation,

  			event->mmap2.prot,
  			event->mmap2.flags,

  			event->mmap2.filename, type, thread);

  
  	if (map == NULL)
  		goto out_problem;
  
  	thread__insert_map(thread, map);
  	return 0;
  
  out_problem:
  	dump_printf("problem processing PERF_RECORD_MMAP2, skipping event.
  ");
  	return 0;
  }

  int machine__process_mmap_event(struct machine *machine, union perf_event *event,
  				struct perf_sample *sample __maybe_unused)

  {
  	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
  	struct thread *thread;
  	struct map *map;

  	enum map_type type;

  	int ret = 0;
  
  	if (dump_trace)
  		perf_event__fprintf_mmap(event, stdout);
  
  	if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
  	    cpumode == PERF_RECORD_MISC_KERNEL) {
  		ret = machine__process_kernel_mmap_event(machine, event);
  		if (ret < 0)
  			goto out_problem;
  		return 0;
  	}

  	thread = machine__findnew_thread(machine, event->mmap.pid,

  					 event->mmap.tid);

  	if (thread == NULL)
  		goto out_problem;

  
  	if (event->header.misc & PERF_RECORD_MISC_MMAP_DATA)
  		type = MAP__VARIABLE;
  	else
  		type = MAP__FUNCTION;

  	map = map__new(machine, event->mmap.start,

  			event->mmap.len, event->mmap.pgoff,

  			event->mmap.pid, 0, 0, 0, 0, 0, 0,

  			event->mmap.filename,

  			type, thread);

  	if (map == NULL)
  		goto out_problem;
  
  	thread__insert_map(thread, map);
  	return 0;
  
  out_problem:
  	dump_printf("problem processing PERF_RECORD_MMAP, skipping event.
  ");
  	return 0;
  }

  static void machine__remove_thread(struct machine *machine, struct thread *th)
  {
  	machine->last_match = NULL;
  	rb_erase(&th->rb_node, &machine->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, &machine->dead_threads);
  }

  int machine__process_fork_event(struct machine *machine, union perf_event *event,
  				struct perf_sample *sample)

  {

  	struct thread *thread = machine__find_thread(machine,
  						     event->fork.pid,
  						     event->fork.tid);

  	struct thread *parent = machine__findnew_thread(machine,
  							event->fork.ppid,
  							event->fork.ptid);

  	/* if a thread currently exists for the thread id remove it */
  	if (thread != NULL)
  		machine__remove_thread(machine, thread);

  	thread = machine__findnew_thread(machine, event->fork.pid,
  					 event->fork.tid);

  	if (dump_trace)
  		perf_event__fprintf_task(event, stdout);
  
  	if (thread == NULL || parent == NULL ||

  	    thread__fork(thread, parent, sample->time) < 0) {

  		dump_printf("problem processing PERF_RECORD_FORK, skipping event.
  ");
  		return -1;
  	}
  
  	return 0;
  }

  int machine__process_exit_event(struct machine *machine, union perf_event *event,
  				struct perf_sample *sample __maybe_unused)

  {

  	struct thread *thread = machine__find_thread(machine,
  						     event->fork.pid,
  						     event->fork.tid);

  
  	if (dump_trace)
  		perf_event__fprintf_task(event, stdout);
  
  	if (thread != NULL)

  		thread__exited(thread);

  
  	return 0;
  }

  int machine__process_event(struct machine *machine, union perf_event *event,
  			   struct perf_sample *sample)

  {
  	int ret;
  
  	switch (event->header.type) {
  	case PERF_RECORD_COMM:

  		ret = machine__process_comm_event(machine, event, sample); break;

  	case PERF_RECORD_MMAP:

  		ret = machine__process_mmap_event(machine, event, sample); break;

  	case PERF_RECORD_MMAP2:

  		ret = machine__process_mmap2_event(machine, event, sample); break;

  	case PERF_RECORD_FORK:

  		ret = machine__process_fork_event(machine, event, sample); break;

  	case PERF_RECORD_EXIT:

  		ret = machine__process_exit_event(machine, event, sample); break;

  	case PERF_RECORD_LOST:

  		ret = machine__process_lost_event(machine, event, sample); break;

  	default:
  		ret = -1;
  		break;
  	}
  
  	return ret;
  }

  static bool symbol__match_regex(struct symbol *sym, regex_t *regex)

  {

  	if (sym->name && !regexec(regex, sym->name, 0, NULL, 0))

  		return 1;

  	return 0;
  }

  static void ip__resolve_ams(struct thread *thread,

  			    struct addr_map_symbol *ams,
  			    u64 ip)
  {
  	struct addr_location al;

  
  	memset(&al, 0, sizeof(al));

  	/*
  	 * We cannot use the header.misc hint to determine whether a
  	 * branch stack address is user, kernel, guest, hypervisor.
  	 * Branches may straddle the kernel/user/hypervisor boundaries.
  	 * Thus, we have to try consecutively until we find a match
  	 * or else, the symbol is unknown
  	 */

  	thread__find_cpumode_addr_location(thread, MAP__FUNCTION, ip, &al);

  	ams->addr = ip;
  	ams->al_addr = al.addr;
  	ams->sym = al.sym;
  	ams->map = al.map;
  }

  static void ip__resolve_data(struct thread *thread,

  			     u8 m, struct addr_map_symbol *ams, u64 addr)
  {
  	struct addr_location al;
  
  	memset(&al, 0, sizeof(al));

  	thread__find_addr_location(thread, m, MAP__VARIABLE, addr, &al);

  	if (al.map == NULL) {
  		/*
  		 * some shared data regions have execute bit set which puts
  		 * their mapping in the MAP__FUNCTION type array.
  		 * Check there as a fallback option before dropping the sample.
  		 */

  		thread__find_addr_location(thread, m, MAP__FUNCTION, addr, &al);

  	}

  	ams->addr = addr;
  	ams->al_addr = al.addr;
  	ams->sym = al.sym;
  	ams->map = al.map;
  }

  struct mem_info *sample__resolve_mem(struct perf_sample *sample,
  				     struct addr_location *al)

  {
  	struct mem_info *mi = zalloc(sizeof(*mi));
  
  	if (!mi)
  		return NULL;

  	ip__resolve_ams(al->thread, &mi->iaddr, sample->ip);
  	ip__resolve_data(al->thread, al->cpumode, &mi->daddr, sample->addr);

  	mi->data_src.val = sample->data_src;
  
  	return mi;
  }

  static int add_callchain_ip(struct thread *thread,
  			    struct symbol **parent,
  			    struct addr_location *root_al,

  			    bool branch_history,

  			    u64 ip)
  {
  	struct addr_location al;
  
  	al.filtered = 0;
  	al.sym = NULL;

  	if (branch_history)

  		thread__find_cpumode_addr_location(thread, MAP__FUNCTION,
  						   ip, &al);

  	else {
  		u8 cpumode = PERF_RECORD_MISC_USER;
  
  		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:
  				pr_debug("invalid callchain context: "
  					 "%"PRId64"
  ", (s64) ip);
  				/*
  				 * It seems the callchain is corrupted.
  				 * Discard all.
  				 */
  				callchain_cursor_reset(&callchain_cursor);
  				return 1;
  			}
  			return 0;
  		}

  		thread__find_addr_location(thread, cpumode, MAP__FUNCTION,

  				   ip, &al);

  	}

  	if (al.sym != NULL) {
  		if (sort__has_parent && !*parent &&
  		    symbol__match_regex(al.sym, &parent_regex))
  			*parent = al.sym;
  		else if (have_ignore_callees && root_al &&
  		  symbol__match_regex(al.sym, &ignore_callees_regex)) {
  			/* Treat this symbol as the root,
  			   forgetting its callees. */
  			*root_al = al;
  			callchain_cursor_reset(&callchain_cursor);
  		}
  	}

  	return callchain_cursor_append(&callchain_cursor, al.addr, al.map, al.sym);

  }

  struct branch_info *sample__resolve_bstack(struct perf_sample *sample,
  					   struct addr_location *al)

  {

  	unsigned int i;

  	const struct branch_stack *bs = sample->branch_stack;
  	struct branch_info *bi = calloc(bs->nr, sizeof(struct branch_info));

  	if (!bi)
  		return NULL;
  
  	for (i = 0; i < bs->nr; i++) {

  		ip__resolve_ams(al->thread, &bi[i].to, bs->entries[i].to);
  		ip__resolve_ams(al->thread, &bi[i].from, bs->entries[i].from);

  		bi[i].flags = bs->entries[i].flags;
  	}
  	return bi;
  }

  #define CHASHSZ 127
  #define CHASHBITS 7
  #define NO_ENTRY 0xff
  
  #define PERF_MAX_BRANCH_DEPTH 127
  
  /* Remove loops. */
  static int remove_loops(struct branch_entry *l, int nr)
  {
  	int i, j, off;
  	unsigned char chash[CHASHSZ];
  
  	memset(chash, NO_ENTRY, sizeof(chash));
  
  	BUG_ON(PERF_MAX_BRANCH_DEPTH > 255);
  
  	for (i = 0; i < nr; i++) {
  		int h = hash_64(l[i].from, CHASHBITS) % CHASHSZ;
  
  		/* no collision handling for now */
  		if (chash[h] == NO_ENTRY) {
  			chash[h] = i;
  		} else if (l[chash[h]].from == l[i].from) {
  			bool is_loop = true;
  			/* check if it is a real loop */
  			off = 0;
  			for (j = chash[h]; j < i && i + off < nr; j++, off++)
  				if (l[j].from != l[i + off].from) {
  					is_loop = false;
  					break;
  				}
  			if (is_loop) {
  				memmove(l + i, l + i + off,
  					(nr - (i + off)) * sizeof(*l));
  				nr -= off;
  			}
  		}
  	}
  	return nr;
  }

  static int thread__resolve_callchain_sample(struct thread *thread,

  					     struct ip_callchain *chain,

  					     struct branch_stack *branch,

  					     struct symbol **parent,

  					     struct addr_location *root_al,
  					     int max_stack)

  {

  	int chain_nr = min(max_stack, (int)chain->nr);

  	int i, j, err;

  	int skip_idx = -1;
  	int first_call = 0;
  
  	/*
  	 * Based on DWARF debug information, some architectures skip
  	 * a callchain entry saved by the kernel.
  	 */
  	if (chain->nr < PERF_MAX_STACK_DEPTH)
  		skip_idx = arch_skip_callchain_idx(thread, chain);

  
  	callchain_cursor_reset(&callchain_cursor);

  	/*
  	 * Add branches to call stack for easier browsing. This gives
  	 * more context for a sample than just the callers.
  	 *
  	 * This uses individual histograms of paths compared to the
  	 * aggregated histograms the normal LBR mode uses.
  	 *
  	 * Limitations for now:
  	 * - No extra filters
  	 * - No annotations (should annotate somehow)
  	 */
  
  	if (branch && callchain_param.branch_callstack) {
  		int nr = min(max_stack, (int)branch->nr);
  		struct branch_entry be[nr];
  
  		if (branch->nr > PERF_MAX_BRANCH_DEPTH) {
  			pr_warning("corrupted branch chain. skipping...
  ");
  			goto check_calls;
  		}
  
  		for (i = 0; i < nr; i++) {
  			if (callchain_param.order == ORDER_CALLEE) {
  				be[i] = branch->entries[i];
  				/*
  				 * Check for overlap into the callchain.
  				 * The return address is one off compared to
  				 * the branch entry. To adjust for this
  				 * assume the calling instruction is not longer
  				 * than 8 bytes.
  				 */
  				if (i == skip_idx ||
  				    chain->ips[first_call] >= PERF_CONTEXT_MAX)
  					first_call++;
  				else if (be[i].from < chain->ips[first_call] &&
  				    be[i].from >= chain->ips[first_call] - 8)
  					first_call++;
  			} else
  				be[i] = branch->entries[branch->nr - i - 1];
  		}
  
  		nr = remove_loops(be, nr);
  
  		for (i = 0; i < nr; i++) {
  			err = add_callchain_ip(thread, parent, root_al,

  					       true, be[i].to);

  			if (!err)
  				err = add_callchain_ip(thread, parent, root_al,

  						       true, be[i].from);

  			if (err == -EINVAL)
  				break;
  			if (err)
  				return err;
  		}
  		chain_nr -= nr;
  	}
  
  check_calls:

  	if (chain->nr > PERF_MAX_STACK_DEPTH) {
  		pr_warning("corrupted callchain. skipping...
  ");
  		return 0;
  	}

  	for (i = first_call; i < chain_nr; i++) {

  		u64 ip;

  
  		if (callchain_param.order == ORDER_CALLEE)

  			j = i;

  		else

  			j = chain->nr - i - 1;
  
  #ifdef HAVE_SKIP_CALLCHAIN_IDX
  		if (j == skip_idx)
  			continue;
  #endif
  		ip = chain->ips[j];

  		err = add_callchain_ip(thread, parent, root_al, false, ip);

  		if (err)

  			return (err < 0) ? err : 0;

  	}
  
  	return 0;
  }
  
  static int unwind_entry(struct unwind_entry *entry, void *arg)
  {
  	struct callchain_cursor *cursor = arg;
  	return callchain_cursor_append(cursor, entry->ip,
  				       entry->map, entry->sym);
  }

  int thread__resolve_callchain(struct thread *thread,
  			      struct perf_evsel *evsel,
  			      struct perf_sample *sample,
  			      struct symbol **parent,
  			      struct addr_location *root_al,
  			      int max_stack)

  {

  	int ret = thread__resolve_callchain_sample(thread, sample->callchain,

  						   sample->branch_stack,

  						   parent, root_al, max_stack);

  	if (ret)
  		return ret;
  
  	/* Can we do dwarf post unwind? */
  	if (!((evsel->attr.sample_type & PERF_SAMPLE_REGS_USER) &&
  	      (evsel->attr.sample_type & PERF_SAMPLE_STACK_USER)))
  		return 0;
  
  	/* Bail out if nothing was captured. */
  	if ((!sample->user_regs.regs) ||
  	    (!sample->user_stack.size))
  		return 0;

  	return unwind__get_entries(unwind_entry, &callchain_cursor,

  				   thread, sample, max_stack);

  
  }

  
  int machine__for_each_thread(struct machine *machine,
  			     int (*fn)(struct thread *thread, void *p),
  			     void *priv)
  {
  	struct rb_node *nd;
  	struct thread *thread;
  	int rc = 0;
  
  	for (nd = rb_first(&machine->threads); nd; nd = rb_next(nd)) {
  		thread = rb_entry(nd, struct thread, rb_node);
  		rc = fn(thread, priv);
  		if (rc != 0)
  			return rc;
  	}
  
  	list_for_each_entry(thread, &machine->dead_threads, node) {
  		rc = fn(thread, priv);
  		if (rc != 0)
  			return rc;
  	}
  	return rc;
  }

  int __machine__synthesize_threads(struct machine *machine, struct perf_tool *tool,

  				  struct target *target, struct thread_map *threads,

  				  perf_event__handler_t process, bool data_mmap)

  {

  	if (target__has_task(target))

  		return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap);

  	else if (target__has_cpu(target))

  		return perf_event__synthesize_threads(tool, process, machine, data_mmap);
  	/* command specified */
  	return 0;
  }

  
  pid_t machine__get_current_tid(struct machine *machine, int cpu)
  {
  	if (cpu < 0 || cpu >= MAX_NR_CPUS || !machine->current_tid)
  		return -1;
  
  	return machine->current_tid[cpu];
  }
  
  int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
  			     pid_t tid)
  {
  	struct thread *thread;
  
  	if (cpu < 0)
  		return -EINVAL;
  
  	if (!machine->current_tid) {
  		int i;
  
  		machine->current_tid = calloc(MAX_NR_CPUS, sizeof(pid_t));
  		if (!machine->current_tid)
  			return -ENOMEM;
  		for (i = 0; i < MAX_NR_CPUS; i++)
  			machine->current_tid[i] = -1;
  	}
  
  	if (cpu >= MAX_NR_CPUS) {
  		pr_err("Requested CPU %d too large. ", cpu);
  		pr_err("Consider raising MAX_NR_CPUS
  ");
  		return -EINVAL;
  	}
  
  	machine->current_tid[cpu] = tid;
  
  	thread = machine__findnew_thread(machine, pid, tid);
  	if (!thread)
  		return -ENOMEM;
  
  	thread->cpu = cpu;
  
  	return 0;
  }

  
  int machine__get_kernel_start(struct machine *machine)
  {
  	struct map *map = machine__kernel_map(machine, MAP__FUNCTION);
  	int err = 0;
  
  	/*
  	 * The only addresses above 2^63 are kernel addresses of a 64-bit
  	 * kernel.  Note that addresses are unsigned so that on a 32-bit system
  	 * all addresses including kernel addresses are less than 2^32.  In
  	 * that case (32-bit system), if the kernel mapping is unknown, all
  	 * addresses will be assumed to be in user space - see
  	 * machine__kernel_ip().
  	 */
  	machine->kernel_start = 1ULL << 63;
  	if (map) {
  		err = map__load(map, machine->symbol_filter);
  		if (map->start)
  			machine->kernel_start = map->start;
  	}
  	return err;
  }