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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 #include <dirent.h>
 #include <errno.h>
 #include <inttypes.h>
 #include <regex.h>
 #include <stdlib.h>
 #include "callchain.h"
 #include "debug.h"
 #include "dso.h"
 #include "env.h"
 #include "event.h"
 #include "evsel.h"
 #include "hist.h"
 #include "machine.h"
 #include "map.h"
 #include "map_symbol.h"
 #include "branch.h"
 #include "mem-events.h"
 #include "path.h"
 #include "srcline.h"
 #include "symbol.h"
 #include "sort.h"
 #include "strlist.h"
 #include "target.h"
 #include "thread.h"
 #include "util.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 "bpf-event.h"
 #include <internal/lib.h> // page_size
 #include "cgroup.h"
 #include "arm64-frame-pointer-unwind-support.h"
 
 #include <linux/ctype.h>
 #include <symbol/kallsyms.h>
 #include <linux/mman.h>
 #include <linux/string.h>
 #include <linux/zalloc.h>
 
 static void __machine__remove_thread(struct machine *machine, struct thread *th, bool lock);
 
 static struct dso *machine__kernel_dso(struct machine *machine)
 {
     return machine->vmlinux_map->dso;
 }
 
 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_CACHED;
         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;
 }
 
 static void thread__set_guest_comm(struct thread *thread, pid_t pid)
 {
     char comm[64];
 
     snprintf(comm, sizeof(comm), "[guest/%d]", pid);
     thread__set_comm(thread, comm, 0);
 }
 
 int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
 {
     int err = -ENOMEM;
 
     memset(machine, 0, sizeof(*machine));
     machine->kmaps = maps__new(machine);
     if (machine->kmaps == NULL)
         return -ENOMEM;
 
     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)
         goto out;
 
     if (machine__set_mmap_name(machine))
         goto out;
 
     if (pid != HOST_KERNEL_ID) {
         struct thread *thread = machine__findnew_thread(machine, -1,
                                 pid);
 
         if (thread == NULL)
             goto out;
 
         thread__set_guest_comm(thread, pid);
         thread__put(thread);
     }
 
     machine->current_tid = NULL;
     err = 0;
 
 out:
     if (err) {
         zfree(&machine->kmaps);
         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 explicitly
      *    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_cached(&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);
     maps__delete(machine->kmaps);
     dsos__exit(&machine->dsos);
     machine__exit_vdso(machine);
     zfree(&machine->root_dir);
     zfree(&machine->mmap_name);
     zfree(&machine->current_tid);
     zfree(&machine->kallsyms_filename);
 
     for (i = 0; i < THREADS__TABLE_SIZE; i++) {
         struct threads *threads = &machine->threads[i];
         struct thread *thread, *n;
         /*
          * Forget about the dead, at this point whatever threads were
          * left in the dead lists better have a reference count taken
          * by who is using them, and then, when they drop those references
          * and it finally hits zero, thread__put() will check and see that
          * its not in the dead threads list and will not try to remove it
          * from there, just calling thread__delete() straight away.
          */
         list_for_each_entry_safe(thread, n, &threads->dead, node)
             list_del_init(&thread->node);
 
         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_CACHED;
 }
 
 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_root.rb_node;
     struct rb_node *parent = NULL;
     struct machine *pos, *machine = malloc(sizeof(*machine));
     bool leftmost = true;
 
     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;
             leftmost = false;
         }
     }
 
     rb_link_node(&machine->rb_node, parent, p);
     rb_insert_color_cached(&machine->rb_node, &machines->guests, leftmost);
 
     machine->machines = machines;
 
     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_cached(&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_root.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;
 }
 
 struct machine *machines__find_guest(struct machines *machines, pid_t pid)
 {
     struct machine *machine = machines__find(machines, pid);
 
     if (!machine)
         machine = machines__findnew(machines, DEFAULT_GUEST_KERNEL_ID);
     return machine;
 }
 
 /*
  * A common case for KVM test programs is that the test program acts as the
  * hypervisor, creating, running and destroying the virtual machine, and
  * providing the guest object code from its own object code. In this case,
  * the VM is not running an OS, but only the functions loaded into it by the
  * hypervisor test program, and conveniently, loaded at the same virtual
  * addresses.
  *
  * Normally to resolve addresses, MMAP events are needed to map addresses
  * back to the object code and debug symbols for that object code.
  *
  * Currently, there is no way to get such mapping information from guests
  * but, in the scenario described above, the guest has the same mappings
  * as the hypervisor, so support for that scenario can be achieved.
  *
  * To support that, copy the host thread's maps to the guest thread's maps.
  * Note, we do not discover the guest until we encounter a guest event,
  * which works well because it is not until then that we know that the host
  * thread's maps have been set up.
  *
  * This function returns the guest thread. Apart from keeping the data
  * structures sane, using a thread belonging to the guest machine, instead
  * of the host thread, allows it to have its own comm (refer
  * thread__set_guest_comm()).
  */
 static struct thread *findnew_guest_code(struct machine *machine,
                      struct machine *host_machine,
                      pid_t pid)
 {
     struct thread *host_thread;
     struct thread *thread;
     int err;
 
     if (!machine)
         return NULL;
 
     thread = machine__findnew_thread(machine, -1, pid);
     if (!thread)
         return NULL;
 
     /* Assume maps are set up if there are any */
     if (thread->maps->nr_maps)
         return thread;
 
     host_thread = machine__find_thread(host_machine, -1, pid);
     if (!host_thread)
         goto out_err;
 
     thread__set_guest_comm(thread, pid);
 
     /*
      * Guest code can be found in hypervisor process at the same address
      * so copy host maps.
      */
     err = maps__clone(thread, host_thread->maps);
     thread__put(host_thread);
     if (err)
         goto out_err;
 
     return thread;
 
 out_err:
     thread__zput(thread);
     return NULL;
 }
 
 struct thread *machines__findnew_guest_code(struct machines *machines, pid_t pid)
 {
     struct machine *host_machine = machines__find(machines, HOST_KERNEL_ID);
     struct machine *machine = machines__findnew(machines, pid);
 
     return findnew_guest_code(machine, host_machine, pid);
 }
 
 struct thread *machine__findnew_guest_code(struct machine *machine, pid_t pid)
 {
     struct machines *machines = machine->machines;
     struct machine *host_machine;
 
     if (!machines)
         return NULL;
 
     host_machine = machines__find(machines, HOST_KERNEL_ID);
 
     return findnew_guest_code(machine, host_machine, pid);
 }
 
 void machines__process_guests(struct machines *machines,
                   machine__process_t process, void *data)
 {
     struct rb_node *nd;
 
     for (nd = rb_first_cached(&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_cached(&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->maps)
         leader->maps = maps__new(machine);
 
     if (!leader->maps)
         goto out_err;
 
     if (th->maps == leader->maps)
         return;
 
     if (th->maps) {
         /*
          * 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 (!maps__empty(th->maps))
             pr_err("Discarding thread maps for %d:%d\n",
                    th->pid_, th->tid);
         maps__put(th->maps);
     }
 
     th->maps = maps__get(leader->maps);
 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;
 }
 
 /*
  * Front-end cache - TID lookups come in blocks,
  * so most of the time we dont have to look up
  * the full rbtree:
  */
 static struct thread*
 __threads__get_last_match(struct threads *threads, struct machine *machine,
               int pid, int tid)
 {
     struct thread *th;
 
     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;
     }
 
     return NULL;
 }
 
 static struct thread*
 threads__get_last_match(struct threads *threads, struct machine *machine,
             int pid, int tid)
 {
     struct thread *th = NULL;
 
     if (perf_singlethreaded)
         th = __threads__get_last_match(threads, machine, pid, tid);
 
     return th;
 }
 
 static void
 __threads__set_last_match(struct threads *threads, struct thread *th)
 {
     threads->last_match = th;
 }
 
 static void
 threads__set_last_match(struct threads *threads, struct thread *th)
 {
     if (perf_singlethreaded)
         __threads__set_last_match(threads, th);
 }
 
 /*
  * 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_root.rb_node;
     struct rb_node *parent = NULL;
     struct thread *th;
     bool leftmost = true;
 
     th = threads__get_last_match(threads, machine, pid, tid);
     if (th)
         return th;
 
     while (*p != NULL) {
         parent = *p;
         th = rb_entry(parent, struct thread, rb_node);
 
         if (th->tid == tid) {
             threads__set_last_match(threads, 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;
             leftmost = false;
         }
     }
 
     if (!create)
         return NULL;
 
     th = thread__new(pid, tid);
     if (th != NULL) {
         rb_link_node(&th->rb_node, parent, p);
         rb_insert_color_cached(&th->rb_node, &threads->entries, leftmost);
 
         /*
          * We have to initialize maps separately after rb tree is updated.
          *
          * The reason is that we call machine__findnew_thread
          * within thread__init_maps to find the thread
          * leader and that would screwed the rb tree.
          */
         if (thread__init_maps(th, machine)) {
             rb_erase_cached(&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__set_last_match(threads, 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;
 }
 
 /*
  * Threads are identified by pid and tid, and the idle task has pid == tid == 0.
  * So here a single thread is created for that, but actually there is a separate
  * idle task per cpu, so there should be one 'struct thread' per cpu, but there
  * is only 1. That causes problems for some tools, requiring workarounds. For
  * example get_idle_thread() in builtin-sched.c, or thread_stack__per_cpu().
  */
 struct thread *machine__idle_thread(struct machine *machine)
 {
     struct thread *thread = machine__findnew_thread(machine, 0, 0);
 
     if (!thread || thread__set_comm(thread, "swapper", 0) ||
         thread__set_namespaces(thread, 0, NULL))
         pr_err("problem inserting idle task for machine pid %d\n", machine->pid);
 
     return thread;
 }
 
 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_cgroup_event(struct machine *machine,
                   union perf_event *event,
                   struct perf_sample *sample __maybe_unused)
 {
     struct cgroup *cgrp;
 
     if (dump_trace)
         perf_event__fprintf_cgroup(event, stdout);
 
     cgrp = cgroup__findnew(machine->env, event->cgroup.id, event->cgroup.path);
     if (cgrp == NULL)
         return -ENOMEM;
 
     return 0;
 }
 
 int machine__process_lost_event(struct machine *machine __maybe_unused,
                 union perf_event *event, struct perf_sample *sample __maybe_unused)
 {
     dump_printf(": id:%" PRI_lu64 ": lost:%" PRI_lu64 "\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 :%" PRI_lu64 "\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->kernel = DSO_SPACE__KERNEL;
     }
 
     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_aux_output_hw_id_event(struct machine *machine __maybe_unused,
                         union perf_event *event)
 {
     if (dump_trace)
         perf_event__fprintf_aux_output_hw_id(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 int machine__process_ksymbol_register(struct machine *machine,
                          union perf_event *event,
                          struct perf_sample *sample __maybe_unused)
 {
     struct symbol *sym;
     struct map *map = maps__find(machine__kernel_maps(machine), event->ksymbol.addr);
 
     if (!map) {
         struct dso *dso = dso__new(event->ksymbol.name);
 
         if (dso) {
             dso->kernel = DSO_SPACE__KERNEL;
             map = map__new2(0, dso);
             dso__put(dso);
         }
 
         if (!dso || !map) {
             return -ENOMEM;
         }
 
         if (event->ksymbol.ksym_type == PERF_RECORD_KSYMBOL_TYPE_OOL) {
             map->dso->binary_type = DSO_BINARY_TYPE__OOL;
             map->dso->data.file_size = event->ksymbol.len;
             dso__set_loaded(map->dso);
         }
 
         map->start = event->ksymbol.addr;
         map->end = map->start + event->ksymbol.len;
         maps__insert(machine__kernel_maps(machine), map);
         map__put(map);
         dso__set_loaded(dso);
 
         if (is_bpf_image(event->ksymbol.name)) {
             dso->binary_type = DSO_BINARY_TYPE__BPF_IMAGE;
             dso__set_long_name(dso, "", false);
         }
     }
 
     sym = symbol__new(map->map_ip(map, map->start),
               event->ksymbol.len,
               0, 0, event->ksymbol.name);
     if (!sym)
         return -ENOMEM;
     dso__insert_symbol(map->dso, sym);
     return 0;
 }
 
 static int machine__process_ksymbol_unregister(struct machine *machine,
                            union perf_event *event,
                            struct perf_sample *sample __maybe_unused)
 {
     struct symbol *sym;
     struct map *map;
 
     map = maps__find(machine__kernel_maps(machine), event->ksymbol.addr);
     if (!map)
         return 0;
 
     if (map != machine->vmlinux_map)
         maps__remove(machine__kernel_maps(machine), map);
     else {
         sym = dso__find_symbol(map->dso, map->map_ip(map, map->start));
         if (sym)
             dso__delete_symbol(map->dso, sym);
     }
 
     return 0;
 }
 
 int machine__process_ksymbol(struct machine *machine __maybe_unused,
                  union perf_event *event,
                  struct perf_sample *sample)
 {
     if (dump_trace)
         perf_event__fprintf_ksymbol(event, stdout);
 
     if (event->ksymbol.flags & PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER)
         return machine__process_ksymbol_unregister(machine, event,
                                sample);
     return machine__process_ksymbol_register(machine, event, sample);
 }
 
 int machine__process_text_poke(struct machine *machine, union perf_event *event,
                    struct perf_sample *sample __maybe_unused)
 {
     struct map *map = maps__find(machine__kernel_maps(machine), event->text_poke.addr);
     u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
 
     if (dump_trace)
         perf_event__fprintf_text_poke(event, machine, stdout);
 
     if (!event->text_poke.new_len)
         return 0;
 
     if (cpumode != PERF_RECORD_MISC_KERNEL) {
         pr_debug("%s: unsupported cpumode - ignoring\n", __func__);
         return 0;
     }
 
     if (map && map->dso) {
         u8 *new_bytes = event->text_poke.bytes + event->text_poke.old_len;
         int ret;
 
         /*
          * Kernel maps might be changed when loading symbols so loading
          * must be done prior to using kernel maps.
          */
         map__load(map);
         ret = dso__data_write_cache_addr(map->dso, map, machine,
                          event->text_poke.addr,
                          new_bytes,
                          event->text_poke.new_len);
         if (ret != event->text_poke.new_len)
             pr_debug("Failed to write kernel text poke at %#" PRI_lx64 "\n",
                  event->text_poke.addr);
     } else {
         pr_debug("Failed to find kernel text poke address map for %#" PRI_lx64 "\n",
              event->text_poke.addr);
     }
 
     return 0;
 }
 
 static struct map *machine__addnew_module_map(struct machine *machine, u64 start,
                           const char *filename)
 {
     struct map *map = NULL;
     struct kmod_path m;
     struct dso *dso;
 
     if (kmod_path__parse_name(&m, filename))
         return NULL;
 
     dso = machine__findnew_module_dso(machine, &m, filename);
     if (dso == NULL)
         goto out;
 
     map = map__new2(start, dso);
     if (map == NULL)
         goto out;
 
     maps__insert(machine__kernel_maps(machine), map);
 
     /* Put the map here because maps__insert already got it */
     map__put(map);
 out:
     /* put the dso here, corresponding to  machine__findnew_module_dso */
     dso__put(dso);
     zfree(&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_cached(&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_cached(&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_dso(machine);
 
     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_cached(&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_SPACE__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_SPACE__KERNEL_GUEST);
     }
 
     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, u64 *end)
 {
     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;
 
     err = kallsyms__get_function_start(filename, "_etext", &addr);
     if (!err)
         *end = 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);
 
     strlcpy(kmap->name, xm->name, KMAP_NAME_LEN);
 
     maps__insert(machine__kernel_maps(machine), 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 maps *kmaps = machine__kernel_maps(machine);
     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.
      */
     maps__for_each_entry(kmaps, map) {
         struct kmap *kmap = __map__kmap(map);
         struct map *dest_map;
 
         if (!kmap || !is_entry_trampoline(kmap->name))
             continue;
 
         dest_map = maps__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)
 {
     /* 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;
     maps__insert(machine__kernel_maps(machine), machine->vmlinux_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);
     maps__remove(machine__kernel_maps(machine), 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_cached(&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_cached(&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.
          */
         maps__fixup_end(machine__kernel_maps(machine));
     }
 
     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;
 
     tmp = fgets(version, sizeof(version), file);
     fclose(file);
     if (!tmp)
         return NULL;
 
     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 maps__set_module_path(struct maps *maps, const char *path, struct kmod_path *m)
 {
     char *long_name;
     struct map *map = maps__find_by_name(maps, 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++;
         map->dso->comp = m->comp;
     }
 
     return 0;
 }
 
 static int maps__set_modules_path_dir(struct maps *maps, 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*/
         path__join(path, sizeof(path), 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 = maps__set_modules_path_dir(maps, 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 = maps__set_module_path(maps, path, &m);
 
             zfree(&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 maps__set_modules_path_dir(machine__kernel_maps(machine), modules_path, 0);
 }
 int __weak arch__fix_module_text_start(u64 *start __maybe_unused,
                 u64 *size __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, &size, name) < 0)
         return -1;
 
     map = machine__addnew_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;
 }
 
 static void machine__update_kernel_mmap(struct machine *machine,
                      u64 start, u64 end)
 {
     struct map *map = machine__kernel_map(machine);
 
     map__get(map);
     maps__remove(machine__kernel_maps(machine), map);
 
     machine__set_kernel_mmap(machine, start, end);
 
     maps__insert(machine__kernel_maps(machine), map);
     map__put(map);
 }
 
 int machine__create_kernel_maps(struct machine *machine)
 {
     struct dso *kernel = machine__get_kernel(machine);
     const char *name = NULL;
     struct map *map;
     u64 start = 0, end = ~0ULL;
     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, &start, &end)) {
         if (name &&
             map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map, name, start)) {
             machine__destroy_kernel_maps(machine);
             ret = -1;
             goto out_put;
         }
 
         /*
          * we have a real start address now, so re-order the kmaps
          * assume it's the last in the kmaps
          */
         machine__update_kernel_mmap(machine, start, end);
     }
 
     if (machine__create_extra_kernel_maps(machine, kernel))
         pr_debug("Problems creating extra kernel maps, continuing anyway...\n");
 
     if (end == ~0ULL) {
         /* 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, start, 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,
                          struct extra_kernel_map *xm)
 {
     return machine__is(machine, "x86_64") &&
            is_entry_trampoline(xm->name);
 }
 
 static int machine__process_extra_kernel_map(struct machine *machine,
                          struct extra_kernel_map *xm)
 {
     struct dso *kernel = machine__kernel_dso(machine);
 
     if (kernel == NULL)
         return -1;
 
     return machine__create_extra_kernel_map(machine, kernel, xm);
 }
 
 static int machine__process_kernel_mmap_event(struct machine *machine,
                           struct extra_kernel_map *xm,
                           struct build_id *bid)
 {
     struct map *map;
     enum dso_space_type dso_space;
     bool is_kernel_mmap;
     const char *mmap_name = machine->mmap_name;
 
     /* 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))
         dso_space = DSO_SPACE__KERNEL;
     else
         dso_space = DSO_SPACE__KERNEL_GUEST;
 
     is_kernel_mmap = memcmp(xm->name, mmap_name, strlen(mmap_name) - 1) == 0;
     if (!is_kernel_mmap && !machine__is_host(machine)) {
         /*
          * If the event was recorded inside the guest and injected into
          * the host perf.data file, then it will match a host mmap_name,
          * so try that - see machine__set_mmap_name().
          */
         mmap_name = "[kernel.kallsyms]";
         is_kernel_mmap = memcmp(xm->name, mmap_name, strlen(mmap_name) - 1) == 0;
     }
     if (xm->name[0] == '/' ||
         (!is_kernel_mmap && xm->name[0] == '[')) {
         map = machine__addnew_module_map(machine, xm->start,
                          xm->name);
         if (map == NULL)
             goto out_problem;
 
         map->end = map->start + xm->end - xm->start;
 
         if (build_id__is_defined(bid))
             dso__set_build_id(map->dso, bid);
 
     } else if (is_kernel_mmap) {
         const char *symbol_name = xm->name + strlen(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 = dso_space;
         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__update_kernel_mmap(machine, xm->start, xm->end);
 
         if (build_id__is_defined(bid))
             dso__set_build_id(kernel, bid);
 
         /*
          * 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 (xm->pgoff != 0) {
             map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map,
                             symbol_name,
                             xm->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, xm)) {
         return machine__process_extra_kernel_map(machine, xm);
     }
     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;
     struct dso_id dso_id = {
         .maj = event->mmap2.maj,
         .min = event->mmap2.min,
         .ino = event->mmap2.ino,
         .ino_generation = event->mmap2.ino_generation,
     };
     struct build_id __bid, *bid = NULL;
     int ret = 0;
 
     if (dump_trace)
         perf_event__fprintf_mmap2(event, stdout);
 
     if (event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) {
         bid = &__bid;
         build_id__init(bid, event->mmap2.build_id, event->mmap2.build_id_size);
     }
 
     if (sample->cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
         sample->cpumode == PERF_RECORD_MISC_KERNEL) {
         struct extra_kernel_map xm = {
             .start = event->mmap2.start,
             .end   = event->mmap2.start + event->mmap2.len,
             .pgoff = event->mmap2.pgoff,
         };
 
         strlcpy(xm.name, event->mmap2.filename, KMAP_NAME_LEN);
         ret = machine__process_kernel_mmap_event(machine, &xm, bid);
         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,
             &dso_id, event->mmap2.prot,
             event->mmap2.flags, bid,
             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) {
         struct extra_kernel_map xm = {
             .start = event->mmap.start,
             .end   = event->mmap.start + event->mmap.len,
             .pgoff = event->mmap.pgoff,
         };
 
         strlcpy(xm.name, event->mmap.filename, KMAP_NAME_LEN);
         ret = machine__process_kernel_mmap_event(machine, &xm, NULL);
         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,
             NULL, prot, 0, NULL, 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__set_last_match(threads, NULL);
 
     if (lock)
         down_write(&threads->lock);
 
     BUG_ON(refcount_read(&th->refcnt) == 0);
 
     rb_erase_cached(&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);
 
     /*
      * We need to do the put here because if this is the last refcount,
      * then we will be touching the threads->dead head when removing the
      * thread.
      */
     thread__put(th);
 
     if (lock)
         up_write(&threads->lock);
 }
 
 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);
     bool do_maps_clone = true;
     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);
     /*
      * When synthesizing FORK events, we are trying to create thread
      * objects for the already running tasks on the machine.
      *
      * Normally, for a kernel FORK event, we want to clone the parent's
      * maps because that is what the kernel just did.
      *
      * But when synthesizing, this should not be done.  If we do, we end up
      * with overlapping maps as we process the synthesized MMAP2 events that
      * get delivered shortly thereafter.
      *
      * Use the FORK event misc flags in an internal way to signal this
      * situation, so we can elide the map clone when appropriate.
      */
     if (event->fork.header.misc & PERF_RECORD_MISC_FORK_EXEC)
         do_maps_clone = false;
 
     if (thread == NULL || parent == NULL ||
         thread__fork(thread, parent, sample->time, do_maps_clone) < 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_CGROUP:
         ret = machine__process_cgroup_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;
     case PERF_RECORD_KSYMBOL:
         ret = machine__process_ksymbol(machine, event, sample); break;
     case PERF_RECORD_BPF_EVENT:
         ret = machine__process_bpf(machine, event, sample); break;
     case PERF_RECORD_TEXT_POKE:
         ret = machine__process_text_poke(machine, event, sample); break;
     case PERF_RECORD_AUX_OUTPUT_HW_ID:
         ret = machine__process_aux_output_hw_id_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 true;
     return false;
 }
 
 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->al_level = al.level;
     ams->ms.maps = al.maps;
     ams->ms.sym = al.sym;
     ams->ms.map = al.map;
     ams->phys_addr = 0;
     ams->data_page_size = 0;
 }
 
 static void ip__resolve_data(struct thread *thread,
                  u8 m, struct addr_map_symbol *ams,
                  u64 addr, u64 phys_addr, u64 daddr_page_size)
 {
     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->al_level = al.level;
     ams->ms.maps = al.maps;
     ams->ms.sym = al.sym;
     ams->ms.map = al.map;
     ams->phys_addr = phys_addr;
     ams->data_page_size = daddr_page_size;
 }
 
 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,
              sample->data_page_size);
     mi->data_src.val = sample->data_src;
 
     return mi;
 }
 
 static char *callchain_srcline(struct map_symbol *ms, u64 ip)
 {
     struct map *map = ms->map;
     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),
                       ms->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 map_symbol ms;
     struct addr_location al;
     int nr_loop_iter = 0;
     u64 iter_cycles = 0;
     const char *srcline = NULL;
 
     al.filtered = 0;
     al.sym = NULL;
     al.srcline = 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;
     }
 
     ms.maps = al.maps;
     ms.map = al.map;
     ms.sym = al.sym;
     srcline = callchain_srcline(&ms, al.addr);
     return callchain_cursor_append(cursor, ip, &ms,
                        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_entry *entries = perf_sample__branch_entries(sample);
     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, entries[i].to);
         ip__resolve_ams(al->thread, &bi[i].from, entries[i].from);
         bi[i].flags = entries[i].flags;
     }
     return bi;
 }
 
 static void save_iterations(struct iterations *iter,
                 struct branch_entry *be, int nr)
 {
     int i;
 
     iter->nr_loop_iter++;
     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;
 }
 
 static int lbr_callchain_add_kernel_ip(struct thread *thread,
                        struct callchain_cursor *cursor,
                        struct perf_sample *sample,
                        struct symbol **parent,
                        struct addr_location *root_al,
                        u64 branch_from,
                        bool callee, int end)
 {
     struct ip_callchain *chain = sample->callchain;
     u8 cpumode = PERF_RECORD_MISC_USER;
     int err, i;
 
     if (callee) {
         for (i = 0; i < end + 1; i++) {
             err = add_callchain_ip(thread, cursor, parent,
                            root_al, &cpumode, chain->ips[i],
                            false, NULL, NULL, branch_from);
             if (err)
                 return err;
         }
         return 0;
     }
 
     for (i = end; i >= 0; i--) {
         err = add_callchain_ip(thread, cursor, parent,
                        root_al, &cpumode, chain->ips[i],
                        false, NULL, NULL, branch_from);
         if (err)
             return err;
     }
 
     return 0;
 }
 
 static void save_lbr_cursor_node(struct thread *thread,
                  struct callchain_cursor *cursor,
                  int idx)
 {
     struct lbr_stitch *lbr_stitch = thread->lbr_stitch;
 
     if (!lbr_stitch)
         return;
 
     if (cursor->pos == cursor->nr) {
         lbr_stitch->prev_lbr_cursor[idx].valid = false;
         return;
     }
 
     if (!cursor->curr)
         cursor->curr = cursor->first;
     else
         cursor->curr = cursor->curr->next;
     memcpy(&lbr_stitch->prev_lbr_cursor[idx], cursor->curr,
            sizeof(struct callchain_cursor_node));
 
     lbr_stitch->prev_lbr_cursor[idx].valid = true;
     cursor->pos++;
 }
 
 static int lbr_callchain_add_lbr_ip(struct thread *thread,
                     struct callchain_cursor *cursor,
                     struct perf_sample *sample,
                     struct symbol **parent,
                     struct addr_location *root_al,
                     u64 *branch_from,
                     bool callee)
 {
     struct branch_stack *lbr_stack = sample->branch_stack;
     struct branch_entry *entries = perf_sample__branch_entries(sample);
     u8 cpumode = PERF_RECORD_MISC_USER;
     int lbr_nr = lbr_stack->nr;
     struct branch_flags *flags;
     int err, i;
     u64 ip;
 
     /*
      * The curr and pos are not used in writing session. They are cleared
      * in callchain_cursor_commit() when the writing session is closed.
      * Using curr and pos to track the current cursor node.
      */
     if (thread->lbr_stitch) {
         cursor->curr = NULL;
         cursor->pos = cursor->nr;
         if (cursor->nr) {
             cursor->curr = cursor->first;
             for (i = 0; i < (int)(cursor->nr - 1); i++)
                 cursor->curr = cursor->curr->next;
         }
     }
 
     if (callee) {
         /* Add LBR ip from first entries.to */
         ip = entries[0].to;
         flags = &entries[0].flags;
         *branch_from = entries[0].from;
         err = add_callchain_ip(thread, cursor, parent,
                        root_al, &cpumode, ip,
                        true, flags, NULL,
                        *branch_from);
         if (err)
             return err;
 
         /*
          * The number of cursor node increases.
          * Move the current cursor node.
          * But does not need to save current cursor node for entry 0.
          * It's impossible to stitch the whole LBRs of previous sample.
          */
         if (thread->lbr_stitch && (cursor->pos != cursor->nr)) {
             if (!cursor->curr)
                 cursor->curr = cursor->first;
             else
                 cursor->curr = cursor->curr->next;
             cursor->pos++;
         }
 
         /* Add LBR ip from entries.from one by one. */
         for (i = 0; i < lbr_nr; i++) {
             ip = entries[i].from;
             flags = &entries[i].flags;
             err = add_callchain_ip(thread, cursor, parent,
                            root_al, &cpumode, ip,
                            true, flags, NULL,
                            *branch_from);
             if (err)
                 return err;
             save_lbr_cursor_node(thread, cursor, i);
         }
         return 0;
     }
 
     /* Add LBR ip from entries.from one by one. */
     for (i = lbr_nr - 1; i >= 0; i--) {
         ip = entries[i].from;
         flags = &entries[i].flags;
         err = add_callchain_ip(thread, cursor, parent,
                        root_al, &cpumode, ip,
                        true, flags, NULL,
                        *branch_from);
         if (err)
             return err;
         save_lbr_cursor_node(thread, cursor, i);
     }
 
     /* Add LBR ip from first entries.to */
     ip = entries[0].to;
     flags = &entries[0].flags;
     *branch_from = entries[0].from;
     err = add_callchain_ip(thread, cursor, parent,
                    root_al, &cpumode, ip,
                    true, flags, NULL,
                    *branch_from);
     if (err)
         return err;
 
     return 0;
 }
 
 static int lbr_callchain_add_stitched_lbr_ip(struct thread *thread,
                          struct callchain_cursor *cursor)
 {
     struct lbr_stitch *lbr_stitch = thread->lbr_stitch;
     struct callchain_cursor_node *cnode;
     struct stitch_list *stitch_node;
     int err;
 
     list_for_each_entry(stitch_node, &lbr_stitch->lists, node) {
         cnode = &stitch_node->cursor;
 
         err = callchain_cursor_append(cursor, cnode->ip,
                           &cnode->ms,
                           cnode->branch,
                           &cnode->branch_flags,
                           cnode->nr_loop_iter,
                           cnode->iter_cycles,
                           cnode->branch_from,
                           cnode->srcline);
         if (err)
             return err;
     }
     return 0;
 }
 
 static struct stitch_list *get_stitch_node(struct thread *thread)
 {
     struct lbr_stitch *lbr_stitch = thread->lbr_stitch;
     struct stitch_list *stitch_node;
 
     if (!list_empty(&lbr_stitch->free_lists)) {
         stitch_node = list_first_entry(&lbr_stitch->free_lists,
                            struct stitch_list, node);
         list_del(&stitch_node->node);
 
         return stitch_node;
     }
 
     return malloc(sizeof(struct stitch_list));
 }
 
 static bool has_stitched_lbr(struct thread *thread,
                  struct perf_sample *cur,
                  struct perf_sample *prev,
                  unsigned int max_lbr,
                  bool callee)
 {
     struct branch_stack *cur_stack = cur->branch_stack;
     struct branch_entry *cur_entries = perf_sample__branch_entries(cur);
     struct branch_stack *prev_stack = prev->branch_stack;
     struct branch_entry *prev_entries = perf_sample__branch_entries(prev);
     struct lbr_stitch *lbr_stitch = thread->lbr_stitch;
     int i, j, nr_identical_branches = 0;
     struct stitch_list *stitch_node;
     u64 cur_base, distance;
 
     if (!cur_stack || !prev_stack)
         return false;
 
     /* Find the physical index of the base-of-stack for current sample. */
     cur_base = max_lbr - cur_stack->nr + cur_stack->hw_idx + 1;
 
     distance = (prev_stack->hw_idx > cur_base) ? (prev_stack->hw_idx - cur_base) :
                              (max_lbr + prev_stack->hw_idx - cur_base);
     /* Previous sample has shorter stack. Nothing can be stitched. */
     if (distance + 1 > prev_stack->nr)
         return false;
 
     /*
      * Check if there are identical LBRs between two samples.
      * Identical LBRs must have same from, to and flags values. Also,
      * they have to be saved in the same LBR registers (same physical
      * index).
      *
      * Starts from the base-of-stack of current sample.
      */
     for (i = distance, j = cur_stack->nr - 1; (i >= 0) && (j >= 0); i--, j--) {
         if ((prev_entries[i].from != cur_entries[j].from) ||
             (prev_entries[i].to != cur_entries[j].to) ||
             (prev_entries[i].flags.value != cur_entries[j].flags.value))
             break;
         nr_identical_branches++;
     }
 
     if (!nr_identical_branches)
         return false;
 
     /*
      * Save the LBRs between the base-of-stack of previous sample
      * and the base-of-stack of current sample into lbr_stitch->lists.
      * These LBRs will be stitched later.
      */
     for (i = prev_stack->nr - 1; i > (int)distance; i--) {
 
         if (!lbr_stitch->prev_lbr_cursor[i].valid)
             continue;
 
         stitch_node = get_stitch_node(thread);
         if (!stitch_node)
             return false;
 
         memcpy(&stitch_node->cursor, &lbr_stitch->prev_lbr_cursor[i],
                sizeof(struct callchain_cursor_node));
 
         if (callee)
             list_add(&stitch_node->node, &lbr_stitch->lists);
         else
             list_add_tail(&stitch_node->node, &lbr_stitch->lists);
     }
 
     return true;
 }
 
 static bool alloc_lbr_stitch(struct thread *thread, unsigned int max_lbr)
 {
     if (thread->lbr_stitch)
         return true;
 
     thread->lbr_stitch = zalloc(sizeof(*thread->lbr_stitch));
     if (!thread->lbr_stitch)
         goto err;
 
     thread->lbr_stitch->prev_lbr_cursor = calloc(max_lbr + 1, sizeof(struct callchain_cursor_node));
     if (!thread->lbr_stitch->prev_lbr_cursor)
         goto free_lbr_stitch;
 
     INIT_LIST_HEAD(&thread->lbr_stitch->lists);
     INIT_LIST_HEAD(&thread->lbr_stitch->free_lists);
 
     return true;
 
 free_lbr_stitch:
     zfree(&thread->lbr_stitch);
 err:
     pr_warning("Failed to allocate space for stitched LBRs. Disable LBR stitch\n");
     thread->lbr_stitch_enable = false;
     return false;
 }
 
 /*
  * Resolve 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,
                     unsigned int max_lbr)
 {
     bool callee = (callchain_param.order == ORDER_CALLEE);
     struct ip_callchain *chain = sample->callchain;
     int chain_nr = min(max_stack, (int)chain->nr), i;
     struct lbr_stitch *lbr_stitch;
     bool stitched_lbr = false;
     u64 branch_from = 0;
     int err;
 
     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)
         return 0;
 
     if (thread->lbr_stitch_enable && !sample->no_hw_idx &&
         (max_lbr > 0) && alloc_lbr_stitch(thread, max_lbr)) {
         lbr_stitch = thread->lbr_stitch;
 
         stitched_lbr = has_stitched_lbr(thread, sample,
                         &lbr_stitch->prev_sample,
                         max_lbr, callee);
 
         if (!stitched_lbr && !list_empty(&lbr_stitch->lists)) {
             list_replace_init(&lbr_stitch->lists,
                       &lbr_stitch->free_lists);
         }
         memcpy(&lbr_stitch->prev_sample, sample, sizeof(*sample));
     }
 
     if (callee) {
         /* Add kernel ip */
         err = lbr_callchain_add_kernel_ip(thread, cursor, sample,
                           parent, root_al, branch_from,
                           true, i);
         if (err)
             goto error;
 
         err = lbr_callchain_add_lbr_ip(thread, cursor, sample, parent,
                            root_al, &branch_from, true);
         if (err)
             goto error;
 
         if (stitched_lbr) {
             err = lbr_callchain_add_stitched_lbr_ip(thread, cursor);
             if (err)
                 goto error;
         }
 
     } else {
         if (stitched_lbr) {
             err = lbr_callchain_add_stitched_lbr_ip(thread, cursor);
             if (err)
                 goto error;
         }
         err = lbr_callchain_add_lbr_ip(thread, cursor, sample, parent,
                            root_al, &branch_from, false);
         if (err)
             goto error;
 
         /* Add kernel ip */
         err = lbr_callchain_add_kernel_ip(thread, cursor, sample,
                           parent, root_al, branch_from,
                           false, i);
         if (err)
             goto error;
     }
     return 1;
 
 error:
     return (err < 0) ? err : 0;
 }
 
 static int find_prev_cpumode(struct ip_callchain *chain, struct thread *thread,
                  struct callchain_cursor *cursor,
                  struct symbol **parent,
                  struct addr_location *root_al,
                  u8 *cpumode, int ent)
 {
     int err = 0;
 
     while (--ent >= 0) {
         u64 ip = chain->ips[ent];
 
         if (ip >= PERF_CONTEXT_MAX) {
             err = add_callchain_ip(thread, cursor, parent,
                            root_al, cpumode, ip,
                            false, NULL, NULL, 0);
             break;
         }
     }
     return err;
 }
 
 static u64 get_leaf_frame_caller(struct perf_sample *sample,
         struct thread *thread, int usr_idx)
 {
     if (machine__normalized_is(thread->maps->machine, "arm64"))
         return get_leaf_frame_caller_aarch64(sample, thread, usr_idx);
     else
         return 0;
 }
 
 static int thread__resolve_callchain_sample(struct thread *thread,
                         struct callchain_cursor *cursor,
                         struct 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 branch_entry *entries = perf_sample__branch_entries(sample);
     struct ip_callchain *chain = sample->callchain;
     int chain_nr = 0;
     u8 cpumode = PERF_RECORD_MISC_USER;
     int i, j, err, nr_entries, usr_idx;
     int skip_idx = -1;
     int first_call = 0;
     u64 leaf_frame_caller;
 
     if (chain)
         chain_nr = chain->nr;
 
     if (evsel__has_branch_callstack(evsel)) {
         struct perf_env *env = evsel__env(evsel);
 
         err = resolve_lbr_callchain_sample(thread, cursor, sample, parent,
                            root_al, max_stack,
                            !env ? 0 : env->max_branches);
         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] = 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] = 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:
     if (chain && callchain_param.order != ORDER_CALLEE) {
         err = find_prev_cpumode(chain, thread, cursor, parent, root_al,
                     &cpumode, chain->nr - first_call);
         if (err)
             return (err < 0) ? err : 0;
     }
     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;
         else if (callchain_param.order != ORDER_CALLEE) {
             err = find_prev_cpumode(chain, thread, cursor, parent,
                         root_al, &cpumode, j);
             if (err)
                 return (err < 0) ? err : 0;
             continue;
         }
 
         /*
          * PERF_CONTEXT_USER allows us to locate where the user stack ends.
          * Depending on callchain_param.order and the position of PERF_CONTEXT_USER,
          * the index will be different in order to add the missing frame
          * at the right place.
          */
 
         usr_idx = callchain_param.order == ORDER_CALLEE ? j-2 : j-1;
 
         if (usr_idx >= 0 && chain->ips[usr_idx] == PERF_CONTEXT_USER) {
 
             leaf_frame_caller = get_leaf_frame_caller(sample, thread, usr_idx);
 
             /*
              * check if leaf_frame_Caller != ip to not add the same
              * value twice.
              */
 
             if (leaf_frame_caller && leaf_frame_caller != ip) {
 
                 err = add_callchain_ip(thread, cursor, parent,
                            root_al, &cpumode, leaf_frame_caller,
                            false, NULL, NULL, 0);
                 if (err)
                     return (err < 0) ? err : 0;
             }
         }
 
         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_symbol *ms, u64 ip)
 {
     struct symbol *sym = ms->sym;
     struct map *map = ms->map;
     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__map_ip(map, ip);
     addr = map__rip_2objdump(map, addr);
 
     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) {
         struct map_symbol ilist_ms = {
             .maps = ms->maps,
             .map = map,
             .sym = ilist->symbol,
         };
         ret = callchain_cursor_append(cursor, ip, &ilist_ms, 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;
     u64 addr = entry->ip;
 
     if (symbol_conf.hide_unresolved && entry->ms.sym == NULL)
         return 0;
 
     if (append_inlines(cursor, &entry->ms, entry->ip) == 0)
         return 0;
 
     /*
      * Convert entry->ip from a virtual address to an offset in
      * its corresponding binary.
      */
     if (entry->ms.map)
         addr = map__map_ip(entry->ms.map, entry->ip);
 
     srcline = callchain_srcline(&entry->ms, addr);
     return callchain_cursor_append(cursor, entry->ip, &entry->ms,
                        false, NULL, 0, 0, 0, srcline);
 }
 
 static int thread__resolve_callchain_unwind(struct thread *thread,
                         struct callchain_cursor *cursor,
                         struct evsel *evsel,
                         struct perf_sample *sample,
                         int max_stack)
 {
     /* Can we do dwarf post unwind? */
     if (!((evsel->core.attr.sample_type & PERF_SAMPLE_REGS_USER) &&
           (evsel->core.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, false);
 }
 
 int thread__resolve_callchain(struct thread *thread,
                   struct callchain_cursor *cursor,
                   struct 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_cached(&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_cached(&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;
 }
 
 pid_t machine__get_current_tid(struct machine *machine, int cpu)
 {
     if (cpu < 0 || (size_t)cpu >= machine->current_tid_sz)
         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;
     const pid_t init_val = -1;
 
     if (cpu < 0)
         return -EINVAL;
 
     if (realloc_array_as_needed(machine->current_tid,
                     machine->current_tid_sz,
                     (unsigned int)cpu,
                     &init_val))
         return -ENOMEM;
 
     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() or
  * machine__normalized_is() 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);
 }
 
 bool machine__normalized_is(struct machine *machine, const char *arch)
 {
     return machine && !strcmp(perf_env__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;
 }
 
 u8 machine__addr_cpumode(struct machine *machine, u8 cpumode, u64 addr)
 {
     u8 addr_cpumode = cpumode;
     bool kernel_ip;
 
     if (!machine->single_address_space)
         goto out;
 
     kernel_ip = machine__kernel_ip(machine, addr);
     switch (cpumode) {
     case PERF_RECORD_MISC_KERNEL:
     case PERF_RECORD_MISC_USER:
         addr_cpumode = kernel_ip ? PERF_RECORD_MISC_KERNEL :
                        PERF_RECORD_MISC_USER;
         break;
     case PERF_RECORD_MISC_GUEST_KERNEL:
     case PERF_RECORD_MISC_GUEST_USER:
         addr_cpumode = kernel_ip ? PERF_RECORD_MISC_GUEST_KERNEL :
                        PERF_RECORD_MISC_GUEST_USER;
         break;
     default:
         break;
     }
 out:
     return addr_cpumode;
 }
 
 struct dso *machine__findnew_dso_id(struct machine *machine, const char *filename, struct dso_id *id)
 {
     return dsos__findnew_id(&machine->dsos, filename, id);
 }
 
 struct dso *machine__findnew_dso(struct machine *machine, const char *filename)
 {
     return machine__findnew_dso_id(machine, filename, NULL);
 }
 
 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;
 }
 
 int machine__for_each_dso(struct machine *machine, machine__dso_t fn, void *priv)
 {
     struct dso *pos;
     int err = 0;
 
     list_for_each_entry(pos, &machine->dsos.head, node) {
         if (fn(pos, machine, priv))
             err = -1;
     }
     return err;
 }
 
 int machine__for_each_kernel_map(struct machine *machine, machine__map_t fn, void *priv)
 {
     struct maps *maps = machine__kernel_maps(machine);
     struct map *map;
     int err = 0;
 
     for (map = maps__first(maps); map != NULL; map = map__next(map)) {
         err = fn(map, priv);
         if (err != 0) {
             break;
         }
     }
     return err;
 }