#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 __machine__remove_thread(struct machine *machine, struct thread *th, bool lock);

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

int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
{
        memset(machine, 0, sizeof(*machine));
        map_groups__init(&machine->kmaps, machine);
        RB_CLEAR_NODE(&machine->rb_node);
        dsos__init(&machine->dsos);

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

        machine->vdso_info = NULL;
        machine->env = NULL;

        machine->pid = pid;

        machine->symbol_filter = NULL;
        machine->id_hdr_size = 0;
        machine->comm_exec = false;
        machine->kernel_start = 0;

        memset(machine->vmlinux_maps, 0, sizeof(machine->vmlinux_maps));

        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);
                thread__put(thread);
        }

        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__purge(struct dsos *dsos)
{
        struct dso *pos, *n;

        pthread_rwlock_wrlock(&dsos->lock);

        list_for_each_entry_safe(pos, n, &dsos->head, node) {
                RB_CLEAR_NODE(&pos->rb_node);
                pos->root = NULL;
                list_del_init(&pos->node);
                dso__put(pos);
        }

        pthread_rwlock_unlock(&dsos->lock);
}

static void dsos__exit(struct dsos *dsos)
{
        dsos__purge(dsos);
        pthread_rwlock_destroy(&dsos->lock);
}

void machine__delete_threads(struct machine *machine)
{
        struct rb_node *nd;

        pthread_rwlock_wrlock(&machine->threads_lock);
        nd = rb_first(&machine->threads);
        while (nd) {
                struct thread *t = rb_entry(nd, struct thread, rb_node);

                nd = rb_next(nd);
                __machine__remove_thread(machine, t, false);
        }
        pthread_rwlock_unlock(&machine->threads_lock);
}

void machine__exit(struct machine *machine)
{
        machine__destroy_kernel_maps(machine);
        map_groups__exit(&machine->kmaps);
        dsos__exit(&machine->dsos);
        machine__exit_vdso(machine);
        zfree(&machine->root_dir);
        zfree(&machine->current_tid);
        pthread_rwlock_destroy(&machine->threads_lock);
}

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(NULL, NULL);

                        if (!strlist__has_entry(seen, path)) {
                                pr_err("Can't access file %s\n", 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\n",
                               th->pid_, th->tid);
                map_groups__put(th->mg);
        }

        th->mg = map_groups__get(leader->mg);
out_put:
        thread__put(leader);
        return;
out_err:
        pr_err("Failed to join map groups for %d:%d\n", th->pid_, th->tid);
        goto out_put;
}

/*
 * Caller must eventually drop thread->refcnt returned with a successfull
 * lookup/new thread inserted.
 */
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 != NULL) {
                if (th->tid == tid) {
                        machine__update_thread_pid(machine, th, pid);
                        return thread__get(th);
                }

                machine->last_match = NULL;
        }

        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 thread__get(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_init(&th->rb_node, &machine->threads);
                        RB_CLEAR_NODE(&th->rb_node);
                        thread__put(th);
                        return NULL;
                }
                /*
                 * It is now in the rbtree, get a ref
                 */
                thread__get(th);
                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__findnew_thread(struct machine *machine, pid_t pid,
                                       pid_t tid)
{
        struct thread *th;

        pthread_rwlock_wrlock(&machine->threads_lock);
        th = __machine__findnew_thread(machine, pid, tid);
        pthread_rwlock_unlock(&machine->threads_lock);
        return th;
}

struct thread *machine__find_thread(struct machine *machine, pid_t pid,
                                    pid_t tid)
{
        struct thread *th;
        pthread_rwlock_rdlock(&machine->threads_lock);
        th =  ____machine__findnew_thread(machine, pid, tid, false);
        pthread_rwlock_unlock(&machine->threads_lock);
        return th;
}

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;
        int err = 0;

        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.\n");
                err = -1;
        }

        thread__put(thread);

        return err;
}

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 "\n",
                    event->lost.id, event->lost.lost);
        return 0;
}

int machine__process_lost_samples_event(struct machine *machine __maybe_unused,
                                        union perf_event *event, struct perf_sample *sample)
{
        dump_printf(": id:%" PRIu64 ": lost samples :%" PRIu64 "\n",
                    sample->id, event->lost_samples.lost);
        return 0;
}

static struct dso *machine__findnew_module_dso(struct machine *machine,
                                               struct kmod_path *m,
                                               const char *filename)
{
        struct dso *dso;

        pthread_rwlock_wrlock(&machine->dsos.lock);

        dso = __dsos__find(&machine->dsos, m->name, true);
        if (!dso) {
                dso = __dsos__addnew(&machine->dsos, m->name);
                if (dso == NULL)
                        goto out_unlock;

                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 (m->kmod && m->comp)
                        dso->symtab_type++;

                dso__set_short_name(dso, strdup(m->name), true);
                dso__set_long_name(dso, strdup(filename), true);
        }

        dso__get(dso);
out_unlock:
        pthread_rwlock_unlock(&machine->dsos.lock);
        return dso;
}

int machine__process_aux_event(struct machine *machine __maybe_unused,
                               union perf_event *event)
{
        if (dump_trace)
                perf_event__fprintf_aux(event, stdout);
        return 0;
}

int machine__process_itrace_start_event(struct machine *machine __maybe_unused,
                                        union perf_event *event)
{
        if (dump_trace)
                perf_event__fprintf_itrace_start(event, stdout);
        return 0;
}

int machine__process_switch_event(struct machine *machine __maybe_unused,
                                  union perf_event *event)
{
        if (dump_trace)
                perf_event__fprintf_switch(event, stdout);
        return 0;
}

static void dso__adjust_kmod_long_name(struct dso *dso, const char *filename)
{
        const char *dup_filename;

        if (!filename || !dso || !dso->long_name)
                return;
        if (dso->long_name[0] != '[')
                return;
        if (!strchr(filename, '/'))
                return;

        dup_filename = strdup(filename);
        if (!dup_filename)
                return;

        dso__set_long_name(dso, dup_filename, true);
}

struct map *machine__findnew_module_map(struct machine *machine, u64 start,
                                        const char *filename)
{
        struct map *map = NULL;
        struct dso *dso = NULL;
        struct kmod_path m;

        if (kmod_path__parse_name(&m, filename))
                return NULL;

        map = map_groups__find_by_name(&machine->kmaps, MAP__FUNCTION,
                                       m.name);
        if (map) {
                /*
                 * If the map's dso is an offline module, give dso__load()
                 * a chance to find the file path of that module by fixing
                 * long_name.
                 */
                dso__adjust_kmod_long_name(map->dso, filename);
                goto out;
        }

        dso = machine__findnew_module_dso(machine, &m, filename);
        if (dso == NULL)
                goto out;

        map = map__new2(start, dso, MAP__FUNCTION);
        if (map == NULL)
                goto out;

        map_groups__insert(&machine->kmaps, map);

        /* Put the map here because map_groups__insert alread got it */
        map__put(map);
out:
        /* put the dso here, corresponding to  machine__findnew_module_dso */
        dso__put(dso);
        free(m.name);
        return map;
}

size_t machines__fprintf_dsos(struct machines *machines, FILE *fp)
{
        struct rb_node *nd;
        size_t ret = __dsos__fprintf(&machines->host.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->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->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__kernel_map(machine)->dso;

        if (kdso->has_build_id) {
                char filename[PATH_MAX];
                if (dso__build_id_filename(kdso, filename, sizeof(filename)))
                        printed += fprintf(fp, "[0] %s\n", filename);
        }

        for (i = 0; i < vmlinux_path__nr_entries; ++i)
                printed += fprintf(fp, "[%d] %s\n",
                                   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;

        pthread_rwlock_rdlock(&machine->threads_lock);

        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);
        }

        pthread_rwlock_unlock(&machine->threads_lock);

        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 = machine__findnew_kernel(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 = machine__findnew_kernel(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);

        /* In case of renewal the kernel map, destroy previous one */
        machine__destroy_kernel_maps(machine);

        for (type = 0; type < MAP__NR_TYPES; ++type) {
                struct kmap *kmap;
                struct map *map;

                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;
                map = __machine__kernel_map(machine, type);
                kmap = map__kmap(map);
                if (!kmap)
                        return -1;

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

        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;
                struct map *map = __machine__kernel_map(machine, type);

                if (map == NULL)
                        continue;

                kmap = map__kmap(map);
                map_groups__remove(&machine->kmaps, map);
                if (kmap && 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__put(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.\n",
                                         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\n", 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__kernel_map(machine);
        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__kernel_map(machine);
        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 bool is_kmod_dso(struct dso *dso)
{
        return dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
               dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
}

static int map_groups__set_module_path(struct map_groups *mg, const char *path,
                                       struct kmod_path *m)
{
        struct map *map;
        char *long_name;

        map = map_groups__find_by_name(mg, MAP__FUNCTION, m->name);
        if (map == NULL)
                return 0;

        long_name = strdup(path);
        if (long_name == NULL)
                return -ENOMEM;

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

        /*
         * Full name could reveal us kmod compression, so

         * we need to update the symtab_type if needed.
         */
        if (m->comp && is_kmod_dso(map->dso))
                map->dso->symtab_type++;

        return 0;
}

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\n", __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 {
                        struct kmod_path m;

                        ret = kmod_path__parse_name(&m, dent->d_name);
                        if (ret)
                                goto out;

                        if (m.kmod)
                                ret = map_groups__set_module_path(mg, path, &m);

                        free(m.name);

                        if (ret)
                                goto out;
                }
        }

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__findnew_module_map(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...\n");

        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);
        int ret;

        if (!addr || kernel == NULL)
                return -1;

        ret = __machine__create_kernel_maps(machine, kernel);
        dso__put(kernel);
        if (ret < 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...\n");
                else
                        pr_debug("Problems creating module maps for guest %d, "
                                 "continuing anyway...\n", 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->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] == '[')) {
                map = machine__findnew_module_map(machine, event->mmap.start,
                                                  event->mmap.filename);
                if (map == NULL)
                        goto out_problem;

                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;

                pthread_rwlock_rdlock(&machine->dsos.lock);

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

                        /*
                         * The cpumode passed to is_kernel_module is not the
                         * cpumode of *this* event. If we insist on passing
                         * correct cpumode to is_kernel_module, we should
                         * record the cpumode when we adding this dso to the
                         * linked list.
                         *
                         * However we don't really need passing correct
                         * cpumode.  We know the correct cpumode must be kernel
                         * mode (if not, we should not link it onto kernel_dsos
                         * list).
                         *
                         * Therefore, we pass PERF_RECORD_MISC_CPUMODE_UNKNOWN.
                         * is_kernel_module() treats it as a kernel cpumode.
                         */

                        if (!dso->kernel ||
                            is_kernel_module(dso->long_name,
                                             PERF_RECORD_MISC_CPUMODE_UNKNOWN))
                                continue;


                        kernel = dso;
                        break;
                }

                pthread_rwlock_unlock(&machine->dsos.lock);

                if (kernel == NULL)
                        kernel = machine__findnew_dso(machine, kmmap_prefix);
                if (kernel == NULL)
                        goto out_problem;

                kernel->kernel = kernel_type;
                if (__machine__create_kernel_maps(machine, kernel) < 0) {
                        dso__put(kernel);
                        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__kernel_map(machine), NULL);
                }
        }
        return 0;
out_problem:
        return -1;
}

int machine__process_mmap2_event(struct machine *machine,
                                 union perf_event *event,
                                 struct perf_sample *sample)
{
        struct thread *thread;
        struct map *map;
        enum map_type type;
        int ret = 0;

        if (dump_trace)
                perf_event__fprintf_mmap2(event, stdout);

        if (sample->cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
            sample->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_map;

        thread__insert_map(thread, map);
        thread__put(thread);
        map__put(map);
        return 0;

out_problem_map:
        thread__put(thread);
out_problem:
        dump_printf("problem processing PERF_RECORD_MMAP2, skipping event.\n");
        return 0;
}

int machine__process_mmap_event(struct machine *machine, union perf_event *event,
                                struct perf_sample *sample)
{
        struct thread *thread;
        struct map *map;
        enum map_type type;
        int ret = 0;

        if (dump_trace)
                perf_event__fprintf_mmap(event, stdout);

        if (sample->cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
            sample->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_map;

        thread__insert_map(thread, map);
        thread__put(thread);
        map__put(map);
        return 0;

out_problem_map:
        thread__put(thread);
out_problem:
        dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
        return 0;
}

static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock)
{
        if (machine->last_match == th)
                machine->last_match = NULL;

        BUG_ON(atomic_read(&th->refcnt) == 0);
        if (lock)
                pthread_rwlock_wrlock(&machine->threads_lock);
        rb_erase_init(&th->rb_node, &machine->threads);
        RB_CLEAR_NODE(&th->rb_node);
        /*
         * Move it first to the dead_threads list, then drop the reference,
         * if this is the last reference, then the thread__delete destructor
         * will be called and we will remove it from the dead_threads list.
         */
        list_add_tail(&th->node, &machine->dead_threads);
        if (lock)
                pthread_rwlock_unlock(&machine->threads_lock);
        thread__put(th);
}

void machine__remove_thread(struct machine *machine, struct thread *th)
{
        return __machine__remove_thread(machine, th, true);
}

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);
        int err = 0;

        if (dump_trace)
                perf_event__fprintf_task(event, stdout);

        /*
         * There may be an existing thread that is not actually the parent,
         * either because we are processing events out of order, or because the
         * (fork) event that would have removed the thread was lost. Assume the
         * latter case and continue on as best we can.
         */
        if (parent->pid_ != (pid_t)event->fork.ppid) {
                dump_printf("removing erroneous parent thread %d/%d\n",
                            parent->pid_, parent->tid);
                machine__remove_thread(machine, parent);
                thread__put(parent);
                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__put(thread);
        }

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

        if (thread == NULL || parent == NULL ||
            thread__fork(thread, parent, sample->time) < 0) {
                dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
                err = -1;
        }
        thread__put(thread);
        thread__put(parent);

        return err;
}

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);
                thread__put(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;
        case PERF_RECORD_AUX:
                ret = machine__process_aux_event(machine, event); break;
        case PERF_RECORD_ITRACE_START:
                ret = machine__process_itrace_start_event(machine, event); break;
        case PERF_RECORD_LOST_SAMPLES:
                ret = machine__process_lost_samples_event(machine, event, sample); break;
        case PERF_RECORD_SWITCH:
        case PERF_RECORD_SWITCH_CPU_WIDE:
                ret = machine__process_switch_event(machine, event); 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,
                            u8 *cpumode,
                            u64 ip)
{
        struct addr_location al;

        al.filtered = 0;
        al.sym = NULL;
        if (!cpumode) {
                thread__find_cpumode_addr_location(thread, MAP__FUNCTION,
                                                   ip, &al);
        } else {
                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"\n", (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);
                }
        }

        if (symbol_conf.hide_unresolved && al.sym == NULL)
                return 0;
        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;
}

/*
 * Recolve LBR callstack chain sample
 * Return:
 * 1 on success get LBR callchain information
 * 0 no available LBR callchain information, should try fp
 * negative error code on other errors.
 */
static int resolve_lbr_callchain_sample(struct thread *thread,
                                        struct perf_sample *sample,
                                        struct symbol **parent,
                                        struct addr_location *root_al,
                                        int max_stack)
{
        struct ip_callchain *chain = sample->callchain;
        int chain_nr = min(max_stack, (int)chain->nr);
        u8 cpumode = PERF_RECORD_MISC_USER;
        int i, j, err;
        u64 ip;

        for (i = 0; i < chain_nr; i++) {
                if (chain->ips[i] == PERF_CONTEXT_USER)
                        break;
        }

        /* LBR only affects the user callchain */
        if (i != chain_nr) {
                struct branch_stack *lbr_stack = sample->branch_stack;
                int lbr_nr = lbr_stack->nr;
                /*
                 * LBR callstack can only get user call chain.
                 * The mix_chain_nr is kernel call chain
                 * number plus LBR user call chain number.
                 * i is kernel call chain number,
                 * 1 is PERF_CONTEXT_USER,
                 * lbr_nr + 1 is the user call chain number.
                 * For details, please refer to the comments
                 * in callchain__printf
                 */
                int mix_chain_nr = i + 1 + lbr_nr + 1;

                if (mix_chain_nr > PERF_MAX_STACK_DEPTH + PERF_MAX_BRANCH_DEPTH) {
                        pr_warning("corrupted callchain. skipping...\n");
                        return 0;
                }

                for (j = 0; j < mix_chain_nr; j++) {
                        if (callchain_param.order == ORDER_CALLEE) {
                                if (j < i + 1)
                                        ip = chain->ips[j];
                                else if (j > i + 1)
                                        ip = lbr_stack->entries[j - i - 2].from;
                                else
                                        ip = lbr_stack->entries[0].to;
                        } else {
                                if (j < lbr_nr)
                                        ip = lbr_stack->entries[lbr_nr - j - 1].from;
                                else if (j > lbr_nr)
                                        ip = chain->ips[i + 1 - (j - lbr_nr)];
                                else
                                        ip = lbr_stack->entries[0].to;
                        }

                        err = add_callchain_ip(thread, parent, root_al, &cpumode, ip);
                        if (err)
                                return (err < 0) ? err : 0;
                }
                return 1;
        }

        return 0;
}

static int thread__resolve_callchain_sample(struct thread *thread,
                                            struct perf_evsel *evsel,
                                            struct perf_sample *sample,
                                            struct symbol **parent,
                                            struct addr_location *root_al,
                                            int max_stack)
{
        struct branch_stack *branch = sample->branch_stack;
        struct ip_callchain *chain = sample->callchain;
        int chain_nr = min(max_stack, (int)chain->nr);
        u8 cpumode = PERF_RECORD_MISC_USER;
        int i, j, err;
        int skip_idx = -1;
        int first_call = 0;

        callchain_cursor_reset(&callchain_cursor);

        if (has_branch_callstack(evsel)) {
                err = resolve_lbr_callchain_sample(thread, sample, parent,
                                                   root_al, max_stack);
                if (err)
                        return (err < 0) ? err : 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);

        /*
         * 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...\n");
                        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,
                                               NULL, be[i].to);
                        if (!err)
                                err = add_callchain_ip(thread, parent, root_al,
                                                       NULL, be[i].from);
                        if (err == -EINVAL)
                                break;
                        if (err)
                                return err;
                }
                chain_nr -= nr;
        }

check_calls:
        if (chain->nr > PERF_MAX_STACK_DEPTH && (int)chain->nr > max_stack) {
                pr_warning("corrupted callchain. skipping...\n");
                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, &cpumode, 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;

        if (symbol_conf.hide_unresolved && entry->sym == NULL)
                return 0;
        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, evsel,
                                                   sample, 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 machines__for_each_thread(struct machines *machines,
                              int (*fn)(struct thread *thread, void *p),
                              void *priv)
{
        struct rb_node *nd;
        int rc = 0;

        rc = machine__for_each_thread(&machines->host, fn, priv);
        if (rc != 0)
                return rc;

        for (nd = rb_first(&machines->guests); nd; nd = rb_next(nd)) {
                struct machine *machine = rb_entry(nd, struct machine, rb_node);

                rc = machine__for_each_thread(machine, fn, 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,
                                  unsigned int proc_map_timeout)
{
        if (target__has_task(target))
                return perf_event__synthesize_thread_map(tool, threads, process, machine, data_mmap, proc_map_timeout);
        else if (target__has_cpu(target))
                return perf_event__synthesize_threads(tool, process, machine, data_mmap, proc_map_timeout);
        /* 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\n");
                return -EINVAL;
        }

        machine->current_tid[cpu] = tid;

        thread = machine__findnew_thread(machine, pid, tid);
        if (!thread)
                return -ENOMEM;

        thread->cpu = cpu;
        thread__put(thread);

        return 0;
}

int machine__get_kernel_start(struct machine *machine)
{
        struct map *map = machine__kernel_map(machine);
        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;
}

struct dso *machine__findnew_dso(struct machine *machine, const char *filename)
{
        return dsos__findnew(&machine->dsos, filename);
}

char *machine__resolve_kernel_addr(void *vmachine, unsigned long long *addrp, char **modp)
{
        struct machine *machine = vmachine;
        struct map *map;
        struct symbol *sym = map_groups__find_symbol(&machine->kmaps, MAP__FUNCTION, *addrp, &map,  NULL);

        if (sym == NULL)
                return NULL;

        *modp = __map__is_kmodule(map) ? (char *)map->dso->short_name : NULL;
        *addrp = map->unmap_ip(map, sym->start);
        return sym->name;
}