v4.19.13 snapshot.
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
new file mode 100644
index 0000000..2048d39
--- /dev/null
+++ b/tools/perf/util/thread.c
@@ -0,0 +1,395 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "../perf.h"
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <linux/kernel.h>
+#include "session.h"
+#include "thread.h"
+#include "thread-stack.h"
+#include "util.h"
+#include "debug.h"
+#include "namespaces.h"
+#include "comm.h"
+#include "unwind.h"
+
+#include <api/fs/fs.h>
+
+int thread__init_map_groups(struct thread *thread, struct machine *machine)
+{
+ pid_t pid = thread->pid_;
+
+ if (pid == thread->tid || pid == -1) {
+ thread->mg = map_groups__new(machine);
+ } else {
+ struct thread *leader = __machine__findnew_thread(machine, pid, pid);
+ if (leader) {
+ thread->mg = map_groups__get(leader->mg);
+ thread__put(leader);
+ }
+ }
+
+ return thread->mg ? 0 : -1;
+}
+
+struct thread *thread__new(pid_t pid, pid_t tid)
+{
+ char *comm_str;
+ struct comm *comm;
+ struct thread *thread = zalloc(sizeof(*thread));
+
+ if (thread != NULL) {
+ thread->pid_ = pid;
+ thread->tid = tid;
+ thread->ppid = -1;
+ thread->cpu = -1;
+ INIT_LIST_HEAD(&thread->namespaces_list);
+ INIT_LIST_HEAD(&thread->comm_list);
+ init_rwsem(&thread->namespaces_lock);
+ init_rwsem(&thread->comm_lock);
+
+ comm_str = malloc(32);
+ if (!comm_str)
+ goto err_thread;
+
+ snprintf(comm_str, 32, ":%d", tid);
+ comm = comm__new(comm_str, 0, false);
+ free(comm_str);
+ if (!comm)
+ goto err_thread;
+
+ list_add(&comm->list, &thread->comm_list);
+ refcount_set(&thread->refcnt, 1);
+ RB_CLEAR_NODE(&thread->rb_node);
+ /* Thread holds first ref to nsdata. */
+ thread->nsinfo = nsinfo__new(pid);
+ }
+
+ return thread;
+
+err_thread:
+ free(thread);
+ return NULL;
+}
+
+void thread__delete(struct thread *thread)
+{
+ struct namespaces *namespaces, *tmp_namespaces;
+ struct comm *comm, *tmp_comm;
+
+ BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
+
+ thread_stack__free(thread);
+
+ if (thread->mg) {
+ map_groups__put(thread->mg);
+ thread->mg = NULL;
+ }
+ down_write(&thread->namespaces_lock);
+ list_for_each_entry_safe(namespaces, tmp_namespaces,
+ &thread->namespaces_list, list) {
+ list_del(&namespaces->list);
+ namespaces__free(namespaces);
+ }
+ up_write(&thread->namespaces_lock);
+
+ down_write(&thread->comm_lock);
+ list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) {
+ list_del(&comm->list);
+ comm__free(comm);
+ }
+ up_write(&thread->comm_lock);
+
+ unwind__finish_access(thread);
+ nsinfo__zput(thread->nsinfo);
+
+ exit_rwsem(&thread->namespaces_lock);
+ exit_rwsem(&thread->comm_lock);
+ free(thread);
+}
+
+struct thread *thread__get(struct thread *thread)
+{
+ if (thread)
+ refcount_inc(&thread->refcnt);
+ return thread;
+}
+
+void thread__put(struct thread *thread)
+{
+ if (thread && refcount_dec_and_test(&thread->refcnt)) {
+ /*
+ * Remove it from the dead_threads list, as last reference
+ * is gone.
+ */
+ list_del_init(&thread->node);
+ thread__delete(thread);
+ }
+}
+
+struct namespaces *thread__namespaces(const struct thread *thread)
+{
+ if (list_empty(&thread->namespaces_list))
+ return NULL;
+
+ return list_first_entry(&thread->namespaces_list, struct namespaces, list);
+}
+
+static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
+ struct namespaces_event *event)
+{
+ struct namespaces *new, *curr = thread__namespaces(thread);
+
+ new = namespaces__new(event);
+ if (!new)
+ return -ENOMEM;
+
+ list_add(&new->list, &thread->namespaces_list);
+
+ if (timestamp && curr) {
+ /*
+ * setns syscall must have changed few or all the namespaces
+ * of this thread. Update end time for the namespaces
+ * previously used.
+ */
+ curr = list_next_entry(new, list);
+ curr->end_time = timestamp;
+ }
+
+ return 0;
+}
+
+int thread__set_namespaces(struct thread *thread, u64 timestamp,
+ struct namespaces_event *event)
+{
+ int ret;
+
+ down_write(&thread->namespaces_lock);
+ ret = __thread__set_namespaces(thread, timestamp, event);
+ up_write(&thread->namespaces_lock);
+ return ret;
+}
+
+struct comm *thread__comm(const struct thread *thread)
+{
+ if (list_empty(&thread->comm_list))
+ return NULL;
+
+ return list_first_entry(&thread->comm_list, struct comm, list);
+}
+
+struct comm *thread__exec_comm(const struct thread *thread)
+{
+ struct comm *comm, *last = NULL;
+
+ list_for_each_entry(comm, &thread->comm_list, list) {
+ if (comm->exec)
+ return comm;
+ last = comm;
+ }
+
+ return last;
+}
+
+static int ____thread__set_comm(struct thread *thread, const char *str,
+ u64 timestamp, bool exec)
+{
+ struct comm *new, *curr = thread__comm(thread);
+
+ /* Override the default :tid entry */
+ if (!thread->comm_set) {
+ int err = comm__override(curr, str, timestamp, exec);
+ if (err)
+ return err;
+ } else {
+ new = comm__new(str, timestamp, exec);
+ if (!new)
+ return -ENOMEM;
+ list_add(&new->list, &thread->comm_list);
+
+ if (exec)
+ unwind__flush_access(thread);
+ }
+
+ thread->comm_set = true;
+
+ return 0;
+}
+
+int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
+ bool exec)
+{
+ int ret;
+
+ down_write(&thread->comm_lock);
+ ret = ____thread__set_comm(thread, str, timestamp, exec);
+ up_write(&thread->comm_lock);
+ return ret;
+}
+
+int thread__set_comm_from_proc(struct thread *thread)
+{
+ char path[64];
+ char *comm = NULL;
+ size_t sz;
+ int err = -1;
+
+ if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
+ thread->pid_, thread->tid) >= (int)sizeof(path)) &&
+ procfs__read_str(path, &comm, &sz) == 0) {
+ comm[sz - 1] = '\0';
+ err = thread__set_comm(thread, comm, 0);
+ }
+
+ return err;
+}
+
+static const char *__thread__comm_str(const struct thread *thread)
+{
+ const struct comm *comm = thread__comm(thread);
+
+ if (!comm)
+ return NULL;
+
+ return comm__str(comm);
+}
+
+const char *thread__comm_str(const struct thread *thread)
+{
+ const char *str;
+
+ down_read((struct rw_semaphore *)&thread->comm_lock);
+ str = __thread__comm_str(thread);
+ up_read((struct rw_semaphore *)&thread->comm_lock);
+
+ return str;
+}
+
+/* CHECKME: it should probably better return the max comm len from its comm list */
+int thread__comm_len(struct thread *thread)
+{
+ if (!thread->comm_len) {
+ const char *comm = thread__comm_str(thread);
+ if (!comm)
+ return 0;
+ thread->comm_len = strlen(comm);
+ }
+
+ return thread->comm_len;
+}
+
+size_t thread__fprintf(struct thread *thread, FILE *fp)
+{
+ return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
+ map_groups__fprintf(thread->mg, fp);
+}
+
+int thread__insert_map(struct thread *thread, struct map *map)
+{
+ int ret;
+
+ ret = unwind__prepare_access(thread, map, NULL);
+ if (ret)
+ return ret;
+
+ map_groups__fixup_overlappings(thread->mg, map, stderr);
+ map_groups__insert(thread->mg, map);
+
+ return 0;
+}
+
+static int __thread__prepare_access(struct thread *thread)
+{
+ bool initialized = false;
+ int err = 0;
+ struct maps *maps = &thread->mg->maps;
+ struct map *map;
+
+ down_read(&maps->lock);
+
+ for (map = maps__first(maps); map; map = map__next(map)) {
+ err = unwind__prepare_access(thread, map, &initialized);
+ if (err || initialized)
+ break;
+ }
+
+ up_read(&maps->lock);
+
+ return err;
+}
+
+static int thread__prepare_access(struct thread *thread)
+{
+ int err = 0;
+
+ if (symbol_conf.use_callchain)
+ err = __thread__prepare_access(thread);
+
+ return err;
+}
+
+static int thread__clone_map_groups(struct thread *thread,
+ struct thread *parent)
+{
+ /* This is new thread, we share map groups for process. */
+ if (thread->pid_ == parent->pid_)
+ return thread__prepare_access(thread);
+
+ if (thread->mg == parent->mg) {
+ pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
+ thread->pid_, thread->tid, parent->pid_, parent->tid);
+ return 0;
+ }
+
+ /* But this one is new process, copy maps. */
+ if (map_groups__clone(thread, parent->mg) < 0)
+ return -ENOMEM;
+
+ return 0;
+}
+
+int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
+{
+ if (parent->comm_set) {
+ const char *comm = thread__comm_str(parent);
+ int err;
+ if (!comm)
+ return -ENOMEM;
+ err = thread__set_comm(thread, comm, timestamp);
+ if (err)
+ return err;
+ }
+
+ thread->ppid = parent->tid;
+ return thread__clone_map_groups(thread, parent);
+}
+
+void thread__find_cpumode_addr_location(struct thread *thread, u64 addr,
+ struct addr_location *al)
+{
+ size_t i;
+ const u8 cpumodes[] = {
+ PERF_RECORD_MISC_USER,
+ PERF_RECORD_MISC_KERNEL,
+ PERF_RECORD_MISC_GUEST_USER,
+ PERF_RECORD_MISC_GUEST_KERNEL
+ };
+
+ for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
+ thread__find_symbol(thread, cpumodes[i], addr, al);
+ if (al->map)
+ break;
+ }
+}
+
+struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
+{
+ if (thread->pid_ == thread->tid)
+ return thread__get(thread);
+
+ if (thread->pid_ == -1)
+ return NULL;
+
+ return machine__find_thread(machine, thread->pid_, thread->pid_);
+}