machine.c

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// SPDX-License-Identifier: GPL-2.0
#include <dirent.h>
#include <errno.h>
#include <inttypes.h>
#include <regex.h>
#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 <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "unwind.h"
#include "linux/hash.h"
#include "asm/bug.h"

#include "sane_ctype.h"
#include <symbol/kallsyms.h>
#include <linux/mman.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;
    init_rwsem(&dsos->lock);
}

static void machine__threads_init(struct machine *machine)
{
    int i;

    for (i = 0; i < THREADS__TABLE_SIZE; i++) {
        struct threads *threads = &machine->threads[i];
        threads->entries = RB_ROOT;
        init_rwsem(&threads->lock);
        threads->nr = 0;
        INIT_LIST_HEAD(&threads->dead);
        threads->last_match = NULL;
    }
}

static int machine__set_mmap_name(struct machine *machine)
{
    if (machine__is_host(machine))
        machine->mmap_name = strdup("[kernel.kallsyms]");
    else if (machine__is_default_guest(machine))
        machine->mmap_name = strdup("[guest.kernel.kallsyms]");
    else if (asprintf(&machine->mmap_name, "[guest.kernel.kallsyms.%d]",
              machine->pid) < 0)
        machine->mmap_name = NULL;

    return machine->mmap_name ? 0 : -ENOMEM;
}

int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
{
    int err = -ENOMEM;

    memset(machine, 0, sizeof(*machine));
    map_groups__init(&machine->kmaps, machine);
    RB_CLEAR_NODE(&machine->rb_node);
    dsos__init(&machine->dsos);

    machine__threads_init(machine);

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

    machine->pid = pid;

    machine->id_hdr_size = 0;
    machine->kptr_restrict_warned = false;
    machine->comm_exec = false;
    machine->kernel_start = 0;
    machine->vmlinux_map = NULL;

    machine->root_dir = strdup(root_dir);
    if (machine->root_dir == NULL)
        return -ENOMEM;

    if (machine__set_mmap_name(machine))
        goto out;

    if (pid != HOST_KERNEL_ID) {
        struct thread *thread = machine__findnew_thread(machine, -1,
                                pid);
        char comm[64];

        if (thread == NULL)
            goto out;

        snprintf(comm, sizeof(comm), "[guest/%d]", pid);
        thread__set_comm(thread, comm, 0);
        thread__put(thread);
    }

    machine->current_tid = NULL;
    err = 0;

out:
    if (err) {
        zfree(&machine->root_dir);
        zfree(&machine->mmap_name);
    }
    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;
}

struct machine *machine__new_kallsyms(void)
{
    struct machine *machine = machine__new_host();
    /*
     * FIXME:
     * 1) We should switch to machine__load_kallsyms(), i.e. not explicitely
     *    ask for not using the kcore parsing code, once this one is fixed
     *    to create a map per module.
     */
    if (machine && machine__load_kallsyms(machine, "/proc/kallsyms") <= 0) {
        machine__delete(machine);
        machine = NULL;
    }

    return machine;
}

static void dsos__purge(struct dsos *dsos)
{
    struct dso *pos, *n;

    down_write(&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);
    }

    up_write(&dsos->lock);
}

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

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

    for (i = 0; i < THREADS__TABLE_SIZE; i++) {
        struct threads *threads = &machine->threads[i];
        down_write(&threads->lock);
        nd = rb_first(&threads->entries);
        while (nd) {
            struct thread *t = rb_entry(nd, struct thread, rb_node);

            nd = rb_next(nd);
            __machine__remove_thread(machine, t, false);
        }
        up_write(&threads->lock);
    }
}

void machine__exit(struct machine *machine)
{
    int i;

    if (machine == NULL)
        return;

    machine__destroy_kernel_maps(machine);
    map_groups__exit(&machine->kmaps);
    dsos__exit(&machine->dsos);
    machine__exit_vdso(machine);
    zfree(&machine->root_dir);
    zfree(&machine->mmap_name);
    zfree(&machine->current_tid);

    for (i = 0; i < THREADS__TABLE_SIZE; i++) {
        struct threads *threads = &machine->threads[i];
        exit_rwsem(&threads->lock);
    }
}

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

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

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;
    }

    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_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);
    }
}

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 successful
 * lookup/new thread inserted.
 */
static struct thread *____machine__findnew_thread(struct machine *machine,
                          struct threads *threads,
                          pid_t pid, pid_t tid,
                          bool create)
{
    struct rb_node **p = &threads->entries.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 = threads->last_match;
    if (th != NULL) {
        if (th->tid == tid) {
            machine__update_thread_pid(machine, th, pid);
            return thread__get(th);
        }

        threads->last_match = NULL;
    }

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

        if (th->tid == tid) {
            threads->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, &threads->entries);

        /*
         * 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, &threads->entries);
            RB_CLEAR_NODE(&th->rb_node);
            thread__put(th);
            return NULL;
        }
        /*
         * It is now in the rbtree, get a ref
         */
        thread__get(th);
        threads->last_match = th;
        ++threads->nr;
    }

    return th;
}

struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid)
{
    return ____machine__findnew_thread(machine, machine__threads(machine, tid), pid, tid, true);
}

struct thread *machine__findnew_thread(struct machine *machine, pid_t pid,
                       pid_t tid)
{
    struct threads *threads = machine__threads(machine, tid);
    struct thread *th;

    down_write(&threads->lock);
    th = __machine__findnew_thread(machine, pid, tid);
    up_write(&threads->lock);
    return th;
}

struct thread *machine__find_thread(struct machine *machine, pid_t pid,
                    pid_t tid)
{
    struct threads *threads = machine__threads(machine, tid);
    struct thread *th;

    down_read(&threads->lock);
    th =  ____machine__findnew_thread(machine, threads, pid, tid, false);
    up_read(&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_namespaces_event(struct machine *machine __maybe_unused,
                      union perf_event *event,
                      struct perf_sample *sample __maybe_unused)
{
    struct thread *thread = machine__findnew_thread(machine,
                            event->namespaces.pid,
                            event->namespaces.tid);
    int err = 0;

    WARN_ONCE(event->namespaces.nr_namespaces > NR_NAMESPACES,
          "\nWARNING: kernel seems to support more namespaces than perf"
          " tool.\nTry updating the perf tool..\n\n");

    WARN_ONCE(event->namespaces.nr_namespaces < NR_NAMESPACES,
          "\nWARNING: perf tool seems to support more namespaces than"
          " the kernel.\nTry updating the kernel..\n\n");

    if (dump_trace)
        perf_event__fprintf_namespaces(event, stdout);

    if (thread == NULL ||
        thread__set_namespaces(thread, sample->time, &event->namespaces)) {
        dump_printf("problem processing PERF_RECORD_NAMESPACES, 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;

    down_write(&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;

        dso__set_module_info(dso, m, machine);
        dso__set_long_name(dso, strdup(filename), true);
    }

    dso__get(dso);
out_unlock:
    up_write(&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, 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);
    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),
                       false))
            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)
{
    struct rb_node *nd;
    size_t ret;
    int i;

    for (i = 0; i < THREADS__TABLE_SIZE; i++) {
        struct threads *threads = &machine->threads[i];

        down_read(&threads->lock);

        ret = fprintf(fp, "Threads: %u\n", threads->nr);

        for (nd = rb_first(&threads->entries); nd; nd = rb_next(nd)) {
            struct thread *pos = rb_entry(nd, struct thread, rb_node);

            ret += thread__fprintf(pos, fp);
        }

        up_read(&threads->lock);
    }
    return ret;
}

static struct dso *machine__get_kernel(struct machine *machine)
{
    const char *vmlinux_name = machine->mmap_name;
    struct dso *kernel;

    if (machine__is_host(machine)) {
        if (symbol_conf.vmlinux_name)
            vmlinux_name = symbol_conf.vmlinux_name;

        kernel = machine__findnew_kernel(machine, vmlinux_name,
                         "[kernel]", DSO_TYPE_KERNEL);
    } else {
        if (symbol_conf.default_guest_vmlinux_name)
            vmlinux_name = symbol_conf.default_guest_vmlinux_name;

        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;
};

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 int machine__get_running_kernel_start(struct machine *machine,
                         const char **symbol_name, u64 *start)
{
    char filename[PATH_MAX];
    int i, err = -1;
    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++) {
        err = kallsyms__get_function_start(filename, name, &addr);
        if (!err)
            break;
    }

    if (err)
        return -1;

    if (symbol_name)
        *symbol_name = name;

    *start = addr;
    return 0;
}

int machine__create_extra_kernel_map(struct machine *machine,
                     struct dso *kernel,
                     struct extra_kernel_map *xm)
{
    struct kmap *kmap;
    struct map *map;

    map = map__new2(xm->start, kernel);
    if (!map)
        return -1;

    map->end   = xm->end;
    map->pgoff = xm->pgoff;

    kmap = map__kmap(map);

    kmap->kmaps = &machine->kmaps;
    strlcpy(kmap->name, xm->name, KMAP_NAME_LEN);

    map_groups__insert(&machine->kmaps, map);

    pr_debug2("Added extra kernel map %s %" PRIx64 "-%" PRIx64 "\n",
          kmap->name, map->start, map->end);

    map__put(map);

    return 0;
}

static u64 find_entry_trampoline(struct dso *dso)
{
    /* Duplicates are removed so lookup all aliases */
    const char *syms[] = {
        "_entry_trampoline",
        "__entry_trampoline_start",
        "entry_SYSCALL_64_trampoline",
    };
    struct symbol *sym = dso__first_symbol(dso);
    unsigned int i;

    for (; sym; sym = dso__next_symbol(sym)) {
        if (sym->binding != STB_GLOBAL)
            continue;
        for (i = 0; i < ARRAY_SIZE(syms); i++) {
            if (!strcmp(sym->name, syms[i]))
                return sym->start;
        }
    }

    return 0;
}

/*
 * These values can be used for kernels that do not have symbols for the entry
 * trampolines in kallsyms.
 */
#define X86_64_CPU_ENTRY_AREA_PER_CPU   0xfffffe0000000000ULL
#define X86_64_CPU_ENTRY_AREA_SIZE  0x2c000
#define X86_64_ENTRY_TRAMPOLINE     0x6000

/* Map x86_64 PTI entry trampolines */
int machine__map_x86_64_entry_trampolines(struct machine *machine,
                      struct dso *kernel)
{
    struct map_groups *kmaps = &machine->kmaps;
    struct maps *maps = &kmaps->maps;
    int nr_cpus_avail, cpu;
    bool found = false;
    struct map *map;
    u64 pgoff;

    /*
     * In the vmlinux case, pgoff is a virtual address which must now be
     * mapped to a vmlinux offset.
     */
    for (map = maps__first(maps); map; map = map__next(map)) {
        struct kmap *kmap = __map__kmap(map);
        struct map *dest_map;

        if (!kmap || !is_entry_trampoline(kmap->name))
            continue;

        dest_map = map_groups__find(kmaps, map->pgoff);
        if (dest_map != map)
            map->pgoff = dest_map->map_ip(dest_map, map->pgoff);
        found = true;
    }
    if (found || machine->trampolines_mapped)
        return 0;

    pgoff = find_entry_trampoline(kernel);
    if (!pgoff)
        return 0;

    nr_cpus_avail = machine__nr_cpus_avail(machine);

    /* Add a 1 page map for each CPU's entry trampoline */
    for (cpu = 0; cpu < nr_cpus_avail; cpu++) {
        u64 va = X86_64_CPU_ENTRY_AREA_PER_CPU +
             cpu * X86_64_CPU_ENTRY_AREA_SIZE +
             X86_64_ENTRY_TRAMPOLINE;
        struct extra_kernel_map xm = {
            .start = va,
            .end   = va + page_size,
            .pgoff = pgoff,
        };

        strlcpy(xm.name, ENTRY_TRAMPOLINE_NAME, KMAP_NAME_LEN);

        if (machine__create_extra_kernel_map(machine, kernel, &xm) < 0)
            return -1;
    }

    machine->trampolines_mapped = nr_cpus_avail;

    return 0;
}

int __weak machine__create_extra_kernel_maps(struct machine *machine __maybe_unused,
                         struct dso *kernel __maybe_unused)
{
    return 0;
}

static int
__machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
{
    struct kmap *kmap;
    struct map *map;

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

    machine->vmlinux_map = map__new2(0, kernel);
    if (machine->vmlinux_map == NULL)
        return -1;

    machine->vmlinux_map->map_ip = machine->vmlinux_map->unmap_ip = identity__map_ip;
    map = machine__kernel_map(machine);
    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)
{
    struct kmap *kmap;
    struct map *map = machine__kernel_map(machine);

    if (map == NULL)
        return;

    kmap = map__kmap(map);
    map_groups__remove(&machine->kmaps, map);
    if (kmap && kmap->ref_reloc_sym) {
        zfree((char **)&kmap->ref_reloc_sym->name);
        zfree(&kmap->ref_reloc_sym);
    }

    map__zput(machine->vmlinux_map);
}

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)
{
    struct map *map = machine__kernel_map(machine);
    int ret = __dso__load_kallsyms(map->dso, filename, map, true);

    if (ret > 0) {
        dso__set_loaded(map->dso);
        /*
         * 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);
    }

    return ret;
}

int machine__load_vmlinux_path(struct machine *machine)
{
    struct map *map = machine__kernel_map(machine);
    int ret = dso__load_vmlinux_path(map->dso, map);

    if (ret > 0)
        dso__set_loaded(map->dso);

    return ret;
}

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)
{
    char *long_name;
    struct map *map = map_groups__find_by_name(mg, 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);
}
int __weak arch__fix_module_text_start(u64 *start __maybe_unused,
                const char *name __maybe_unused)
{
    return 0;
}

static int machine__create_module(void *arg, const char *name, u64 start,
                  u64 size)
{
    struct machine *machine = arg;
    struct map *map;

    if (arch__fix_module_text_start(&start, name) < 0)
        return -1;

    map = machine__findnew_module_map(machine, start, name);
    if (map == NULL)
        return -1;
    map->end = start + size;

    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;
}

static void machine__set_kernel_mmap(struct machine *machine,
                     u64 start, u64 end)
{
    machine->vmlinux_map->start = start;
    machine->vmlinux_map->end   = end;
    /*
     * Be a bit paranoid here, some perf.data file came with
     * a zero sized synthesized MMAP event for the kernel.
     */
    if (start == 0 && end == 0)
        machine->vmlinux_map->end = ~0ULL;
}

int machine__create_kernel_maps(struct machine *machine)
{
    struct dso *kernel = machine__get_kernel(machine);
    const char *name = NULL;
    struct map *map;
    u64 addr = 0;
    int ret;

    if (kernel == NULL)
        return -1;

    ret = __machine__create_kernel_maps(machine, kernel);
    if (ret < 0)
        goto out_put;

    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);
    }

    if (!machine__get_running_kernel_start(machine, &name, &addr)) {
        if (name &&
            map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map, name, addr)) {
            machine__destroy_kernel_maps(machine);
            ret = -1;
            goto out_put;
        }

        /* we have a real start address now, so re-order the kmaps */
        map = machine__kernel_map(machine);

        map__get(map);
        map_groups__remove(&machine->kmaps, map);

        /* assume it's the last in the kmaps */
        machine__set_kernel_mmap(machine, addr, ~0ULL);

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

    if (machine__create_extra_kernel_maps(machine, kernel))
        pr_debug("Problems creating extra kernel maps, continuing anyway...\n");

    /* update end address of the kernel map using adjacent module address */
    map = map__next(machine__kernel_map(machine));
    if (map)
        machine__set_kernel_mmap(machine, addr, map->start);
out_put:
    dso__put(kernel);
    return ret;
}

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 bool perf_event__is_extra_kernel_mmap(struct machine *machine,
                         union perf_event *event)
{
    return machine__is(machine, "x86_64") &&
           is_entry_trampoline(event->mmap.filename);
}

static int machine__process_extra_kernel_map(struct machine *machine,
                         union perf_event *event)
{
    struct map *kernel_map = machine__kernel_map(machine);
    struct dso *kernel = kernel_map ? kernel_map->dso : NULL;
    struct extra_kernel_map xm = {
        .start = event->mmap.start,
        .end   = event->mmap.start + event->mmap.len,
        .pgoff = event->mmap.pgoff,
    };

    if (kernel == NULL)
        return -1;

    strlcpy(xm.name, event->mmap.filename, KMAP_NAME_LEN);

    return machine__create_extra_kernel_map(machine, kernel, &xm);
}

static int machine__process_kernel_mmap_event(struct machine *machine,
                          union perf_event *event)
{
    struct map *map;
    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;

    if (machine__is_host(machine))
        kernel_type = DSO_TYPE_KERNEL;
    else
        kernel_type = DSO_TYPE_GUEST_KERNEL;

    is_kernel_mmap = memcmp(event->mmap.filename,
                machine->mmap_name,
                strlen(machine->mmap_name) - 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(machine->mmap_name));
        /*
         * Should be there already, from the build-id table in
         * the header.
         */
        struct dso *kernel = NULL;
        struct dso *dso;

        down_read(&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;
        }

        up_read(&machine->dsos.lock);

        if (kernel == NULL)
            kernel = machine__findnew_dso(machine, machine->mmap_name);
        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(machine, event->mmap.start,
                     event->mmap.start + event->mmap.len);

        /*
         * 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) {
            map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map,
                            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));
        }
    } else if (perf_event__is_extra_kernel_mmap(machine, event)) {
        return machine__process_extra_kernel_map(machine, event);
    }
    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;
    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;

    map = map__new(machine, event->mmap2.start,
            event->mmap2.len, event->mmap2.pgoff,
            event->mmap2.maj,
            event->mmap2.min, event->mmap2.ino,
            event->mmap2.ino_generation,
            event->mmap2.prot,
            event->mmap2.flags,
            event->mmap2.filename, thread);

    if (map == NULL)
        goto out_problem_map;

    ret = thread__insert_map(thread, map);
    if (ret)
        goto out_problem_insert;

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

out_problem_insert:
    map__put(map);
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;
    u32 prot = 0;
    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))
        prot = PROT_EXEC;

    map = map__new(machine, event->mmap.start,
            event->mmap.len, event->mmap.pgoff,
            0, 0, 0, 0, prot, 0,
            event->mmap.filename,
            thread);

    if (map == NULL)
        goto out_problem_map;

    ret = thread__insert_map(thread, map);
    if (ret)
        goto out_problem_insert;

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

out_problem_insert:
    map__put(map);
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)
{
    struct threads *threads = machine__threads(machine, th->tid);

    if (threads->last_match == th)
        threads->last_match = NULL;

    BUG_ON(refcount_read(&th->refcnt) == 0);
    if (lock)
        down_write(&threads->lock);
    rb_erase_init(&th->rb_node, &threads->entries);
    RB_CLEAR_NODE(&th->rb_node);
    --threads->nr;
    /*
     * 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, &threads->dead);
    if (lock)
        up_write(&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_NAMESPACES:
        ret = machine__process_namespaces_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 (!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, ip, &al);

    ams->addr = ip;
    ams->al_addr = al.addr;
    ams->sym = al.sym;
    ams->map = al.map;
    ams->phys_addr = 0;
}

static void ip__resolve_data(struct thread *thread,
                 u8 m, struct addr_map_symbol *ams,
                 u64 addr, u64 phys_addr)
{
    struct addr_location al;

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

    thread__find_symbol(thread, m, addr, &al);

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

struct mem_info *sample__resolve_mem(struct perf_sample *sample,
                     struct addr_location *al)
{
    struct mem_info *mi = mem_info__new();

    if (!mi)
        return NULL;

    ip__resolve_ams(al->thread, &mi->iaddr, sample->ip);
    ip__resolve_data(al->thread, al->cpumode, &mi->daddr,
             sample->addr, sample->phys_addr);
    mi->data_src.val = sample->data_src;

    return mi;
}

static char *callchain_srcline(struct map *map, struct symbol *sym, u64 ip)
{
    char *srcline = NULL;

    if (!map || callchain_param.key == CCKEY_FUNCTION)
        return srcline;

    srcline = srcline__tree_find(&map->dso->srclines, ip);
    if (!srcline) {
        bool show_sym = false;
        bool show_addr = callchain_param.key == CCKEY_ADDRESS;

        srcline = get_srcline(map->dso, map__rip_2objdump(map, ip),
                      sym, show_sym, show_addr, ip);
        srcline__tree_insert(&map->dso->srclines, ip, srcline);
    }

    return srcline;
}

struct iterations {
    int nr_loop_iter;
    u64 cycles;
};

static int add_callchain_ip(struct thread *thread,
                struct callchain_cursor *cursor,
                struct symbol **parent,
                struct addr_location *root_al,
                u8 *cpumode,
                u64 ip,
                bool branch,
                struct branch_flags *flags,
                struct iterations *iter,
                u64 branch_from)
{
    struct addr_location al;
    int nr_loop_iter = 0;
    u64 iter_cycles = 0;
    const char *srcline = NULL;

    al.filtered = 0;
    al.sym = NULL;
    if (!cpumode) {
        thread__find_cpumode_addr_location(thread, 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(cursor);
                return 1;
            }
            return 0;
        }
        thread__find_symbol(thread, *cpumode, ip, &al);
    }

    if (al.sym != NULL) {
        if (perf_hpp_list.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(cursor);
        }
    }

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

    if (iter) {
        nr_loop_iter = iter->nr_loop_iter;
        iter_cycles = iter->cycles;
    }

    srcline = callchain_srcline(al.map, al.sym, al.addr);
    return callchain_cursor_append(cursor, ip, al.map, al.sym,
                       branch, flags, nr_loop_iter,
                       iter_cycles, branch_from, srcline);
}

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;
}

static void save_iterations(struct iterations *iter,
                struct branch_entry *be, int nr)
{
    int i;

    iter->nr_loop_iter = nr;
    iter->cycles = 0;

    for (i = 0; i < nr; i++)
        iter->cycles += be[i].flags.cycles;
}

#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,
            struct iterations *iter)
{
    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) {
                j = nr - (i + off);
                if (j > 0) {
                    save_iterations(iter + i + off,
                        l + i, off);

                    memmove(iter + i, iter + i + off,
                        j * sizeof(*iter));

                    memmove(l + i, l + i + off,
                        j * 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 callchain_cursor *cursor,
                    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), i;
    u8 cpumode = PERF_RECORD_MISC_USER;
    u64 ip, branch_from = 0;

    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, j, k;
        bool branch;
        struct branch_flags *flags;
        /*
         * 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;

        for (j = 0; j < mix_chain_nr; j++) {
            int err;
            branch = false;
            flags = NULL;

            if (callchain_param.order == ORDER_CALLEE) {
                if (j < i + 1)
                    ip = chain->ips[j];
                else if (j > i + 1) {
                    k = j - i - 2;
                    ip = lbr_stack->entries[k].from;
                    branch = true;
                    flags = &lbr_stack->entries[k].flags;
                } else {
                    ip = lbr_stack->entries[0].to;
                    branch = true;
                    flags = &lbr_stack->entries[0].flags;
                    branch_from =
                        lbr_stack->entries[0].from;
                }
            } else {
                if (j < lbr_nr) {
                    k = lbr_nr - j - 1;
                    ip = lbr_stack->entries[k].from;
                    branch = true;
                    flags = &lbr_stack->entries[k].flags;
                }
                else if (j > lbr_nr)
                    ip = chain->ips[i + 1 - (j - lbr_nr)];
                else {
                    ip = lbr_stack->entries[0].to;
                    branch = true;
                    flags = &lbr_stack->entries[0].flags;
                    branch_from =
                        lbr_stack->entries[0].from;
                }
            }

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

    return 0;
}

static int thread__resolve_callchain_sample(struct thread *thread,
                        struct callchain_cursor *cursor,
                        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 = 0;
    u8 cpumode = PERF_RECORD_MISC_USER;
    int i, j, err, nr_entries;
    int skip_idx = -1;
    int first_call = 0;

    if (chain)
        chain_nr = chain->nr;

    if (perf_evsel__has_branch_callstack(evsel)) {
        err = resolve_lbr_callchain_sample(thread, cursor, 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.
     */
    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];
        struct iterations iter[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];

                if (chain == NULL)
                    continue;

                /*
                 * 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];
        }

        memset(iter, 0, sizeof(struct iterations) * nr);
        nr = remove_loops(be, nr, iter);

        for (i = 0; i < nr; i++) {
            err = add_callchain_ip(thread, cursor, parent,
                           root_al,
                           NULL, be[i].to,
                           true, &be[i].flags,
                           NULL, be[i].from);

            if (!err)
                err = add_callchain_ip(thread, cursor, parent, root_al,
                               NULL, be[i].from,
                               true, &be[i].flags,
                               &iter[i], 0);
            if (err == -EINVAL)
                break;
            if (err)
                return err;
        }

        if (chain_nr == 0)
            return 0;

        chain_nr -= nr;
    }

check_calls:
    for (i = first_call, nr_entries = 0;
         i < chain_nr && nr_entries < max_stack; 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];

        if (ip < PERF_CONTEXT_MAX)
                       ++nr_entries;

        err = add_callchain_ip(thread, cursor, parent,
                       root_al, &cpumode, ip,
                       false, NULL, NULL, 0);

        if (err)
            return (err < 0) ? err : 0;
    }

    return 0;
}

static int append_inlines(struct callchain_cursor *cursor,
              struct map *map, struct symbol *sym, u64 ip)
{
    struct inline_node *inline_node;
    struct inline_list *ilist;
    u64 addr;
    int ret = 1;

    if (!symbol_conf.inline_name || !map || !sym)
        return ret;

    addr = map__rip_2objdump(map, ip);

    inline_node = inlines__tree_find(&map->dso->inlined_nodes, addr);
    if (!inline_node) {
        inline_node = dso__parse_addr_inlines(map->dso, addr, sym);
        if (!inline_node)
            return ret;
        inlines__tree_insert(&map->dso->inlined_nodes, inline_node);
    }

    list_for_each_entry(ilist, &inline_node->val, list) {
        ret = callchain_cursor_append(cursor, ip, map,
                          ilist->symbol, false,
                          NULL, 0, 0, 0, ilist->srcline);

        if (ret != 0)
            return ret;
    }

    return ret;
}

static int unwind_entry(struct unwind_entry *entry, void *arg)
{
    struct callchain_cursor *cursor = arg;
    const char *srcline = NULL;

    if (symbol_conf.hide_unresolved && entry->sym == NULL)
        return 0;

    if (append_inlines(cursor, entry->map, entry->sym, entry->ip) == 0)
        return 0;

    srcline = callchain_srcline(entry->map, entry->sym, entry->ip);
    return callchain_cursor_append(cursor, entry->ip,
                       entry->map, entry->sym,
                       false, NULL, 0, 0, 0, srcline);
}

static int thread__resolve_callchain_unwind(struct thread *thread,
                        struct callchain_cursor *cursor,
                        struct perf_evsel *evsel,
                        struct perf_sample *sample,
                        int max_stack)
{
    /* 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, cursor,
                   thread, sample, max_stack);
}

int thread__resolve_callchain(struct thread *thread,
                  struct callchain_cursor *cursor,
                  struct perf_evsel *evsel,
                  struct perf_sample *sample,
                  struct symbol **parent,
                  struct addr_location *root_al,
                  int max_stack)
{
    int ret = 0;

    callchain_cursor_reset(cursor);

    if (callchain_param.order == ORDER_CALLEE) {
        ret = thread__resolve_callchain_sample(thread, cursor,
                               evsel, sample,
                               parent, root_al,
                               max_stack);
        if (ret)
            return ret;
        ret = thread__resolve_callchain_unwind(thread, cursor,
                               evsel, sample,
                               max_stack);
    } else {
        ret = thread__resolve_callchain_unwind(thread, cursor,
                               evsel, sample,
                               max_stack);
        if (ret)
            return ret;
        ret = thread__resolve_callchain_sample(thread, cursor,
                               evsel, sample,
                               parent, root_al,
                               max_stack);
    }

    return ret;
}

int machine__for_each_thread(struct machine *machine,
                 int (*fn)(struct thread *thread, void *p),
                 void *priv)
{
    struct threads *threads;
    struct rb_node *nd;
    struct thread *thread;
    int rc = 0;
    int i;

    for (i = 0; i < THREADS__TABLE_SIZE; i++) {
        threads = &machine->threads[i];
        for (nd = rb_first(&threads->entries); 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, &threads->dead, 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,
                  unsigned int nr_threads_synthesize)
{
    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,
                              nr_threads_synthesize);
    /* 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;
}

/*
 * Compares the raw arch string. N.B. see instead perf_env__arch() if a
 * normalized arch is needed.
 */
bool machine__is(struct machine *machine, const char *arch)
{
    return machine && !strcmp(perf_env__raw_arch(machine->env), arch);
}

int machine__nr_cpus_avail(struct machine *machine)
{
    return machine ? perf_env__nr_cpus_avail(machine->env) : 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);
        /*
         * On x86_64, PTI entry trampolines are less than the
         * start of kernel text, but still above 2^63. So leave
         * kernel_start = 1ULL << 63 for x86_64.
         */
        if (!err && !machine__is(machine, "x86_64"))
            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 = machine__find_kernel_symbol(machine, *addrp, &map);

    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;
}