1 files changed, 416 insertions, 0 deletions
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
new file mode 100644
index 000000000..2c146d0c2
--- /dev/null
+++ b/tools/perf/util/thread.c
@@ -0,0 +1,416 @@
+// 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);
+	}
+}
+
+static 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);
+}
+
+struct namespaces *thread__namespaces(const struct thread *thread)
+{
+	struct namespaces *ns;
+
+	down_read((struct rw_semaphore *)&thread->namespaces_lock);
+	ns = __thread__namespaces(thread);
+	up_read((struct rw_semaphore *)&thread->namespaces_lock);
+
+	return ns;
+}
+
+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, *second_last = NULL;
+
+	list_for_each_entry(comm, &thread->comm_list, list) {
+		if (comm->exec)
+			return comm;
+		second_last = last;
+		last = comm;
+	}
+
+	/*
+	 * 'last' with no start time might be the parent's comm of a synthesized
+	 * thread (created by processing a synthesized fork event). For a main
+	 * thread, that is very probably wrong. Prefer a later comm to avoid
+	 * that case.
+	 */
+	if (second_last && !last->start && thread->pid_ == thread->tid)
+		return second_last;
+
+	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_);
+}