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-rw-r--r--tools/perf/util/thread.c478
1 files changed, 478 insertions, 0 deletions
diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
new file mode 100644
index 000000000..665e5c061
--- /dev/null
+++ b/tools/perf/util/thread.c
@@ -0,0 +1,478 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <linux/kernel.h>
+#include <linux/zalloc.h>
+#include "dso.h"
+#include "session.h"
+#include "thread.h"
+#include "thread-stack.h"
+#include "debug.h"
+#include "namespaces.h"
+#include "comm.h"
+#include "map.h"
+#include "symbol.h"
+#include "unwind.h"
+#include "callchain.h"
+
+#include <api/fs/fs.h>
+
+int thread__init_maps(struct thread *thread, struct machine *machine)
+{
+ pid_t pid = thread->pid_;
+
+ if (pid == thread->tid || pid == -1) {
+ thread->maps = maps__new(machine);
+ } else {
+ struct thread *leader = __machine__findnew_thread(machine, pid, pid);
+ if (leader) {
+ thread->maps = maps__get(leader->maps);
+ thread__put(leader);
+ }
+ }
+
+ return thread->maps ? 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;
+ thread->lbr_stitch_enable = false;
+ 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);
+ srccode_state_init(&thread->srccode_state);
+ }
+
+ 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->maps) {
+ maps__put(thread->maps);
+ thread->maps = NULL;
+ }
+ down_write(&thread->namespaces_lock);
+ list_for_each_entry_safe(namespaces, tmp_namespaces,
+ &thread->namespaces_list, list) {
+ list_del_init(&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_init(&comm->list);
+ comm__free(comm);
+ }
+ up_write(&thread->comm_lock);
+
+ nsinfo__zput(thread->nsinfo);
+ srccode_state_free(&thread->srccode_state);
+
+ exit_rwsem(&thread->namespaces_lock);
+ exit_rwsem(&thread->comm_lock);
+ thread__free_stitch_list(thread);
+ 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, if it is in a dead threads list.
+ *
+ * We may not be there anymore if say, the machine where it was
+ * stored was already deleted, so we already removed it from
+ * the dead threads and some other piece of code still keeps a
+ * reference.
+ *
+ * This is what 'perf sched' does and finally drops it in
+ * perf_sched__lat(), where it calls perf_sched__read_events(),
+ * that processes the events by creating a session and deleting
+ * it, which ends up destroying the list heads for the dead
+ * threads, but before it does that it removes all threads from
+ * it using list_del_init().
+ *
+ * So we need to check here if it is in a dead threads list and
+ * if so, remove it before finally deleting the thread, to avoid
+ * an use after free situation.
+ */
+ if (!list_empty(&thread->node))
+ 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(struct thread *thread)
+{
+ struct namespaces *ns;
+
+ down_read(&thread->namespaces_lock);
+ ns = __thread__namespaces(thread);
+ up_read(&thread->namespaces_lock);
+
+ return ns;
+}
+
+static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
+ struct perf_record_namespaces *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 perf_record_namespaces *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->maps);
+ }
+
+ 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(struct thread *thread)
+{
+ const char *str;
+
+ down_read(&thread->comm_lock);
+ str = __thread__comm_str(thread);
+ up_read(&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)) +
+ maps__fprintf(thread->maps, fp);
+}
+
+int thread__insert_map(struct thread *thread, struct map *map)
+{
+ int ret;
+
+ ret = unwind__prepare_access(thread->maps, map, NULL);
+ if (ret)
+ return ret;
+
+ maps__fixup_overlappings(thread->maps, map, stderr);
+ maps__insert(thread->maps, map);
+
+ return 0;
+}
+
+static int __thread__prepare_access(struct thread *thread)
+{
+ bool initialized = false;
+ int err = 0;
+ struct maps *maps = thread->maps;
+ struct map *map;
+
+ down_read(&maps->lock);
+
+ maps__for_each_entry(maps, map) {
+ err = unwind__prepare_access(thread->maps, map, &initialized);
+ if (err || initialized)
+ break;
+ }
+
+ up_read(&maps->lock);
+
+ return err;
+}
+
+static int thread__prepare_access(struct thread *thread)
+{
+ int err = 0;
+
+ if (dwarf_callchain_users)
+ err = __thread__prepare_access(thread);
+
+ return err;
+}
+
+static int thread__clone_maps(struct thread *thread, struct thread *parent, bool do_maps_clone)
+{
+ /* This is new thread, we share map groups for process. */
+ if (thread->pid_ == parent->pid_)
+ return thread__prepare_access(thread);
+
+ if (thread->maps == parent->maps) {
+ 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. */
+ return do_maps_clone ? maps__clone(thread, parent->maps) : 0;
+}
+
+int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone)
+{
+ 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_maps(thread, parent, do_maps_clone);
+}
+
+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_);
+}
+
+int thread__memcpy(struct thread *thread, struct machine *machine,
+ void *buf, u64 ip, int len, bool *is64bit)
+{
+ u8 cpumode = PERF_RECORD_MISC_USER;
+ struct addr_location al;
+ long offset;
+
+ if (machine__kernel_ip(machine, ip))
+ cpumode = PERF_RECORD_MISC_KERNEL;
+
+ if (!thread__find_map(thread, cpumode, ip, &al) || !al.map->dso ||
+ al.map->dso->data.status == DSO_DATA_STATUS_ERROR ||
+ map__load(al.map) < 0)
+ return -1;
+
+ offset = al.map->map_ip(al.map, ip);
+ if (is64bit)
+ *is64bit = al.map->dso->is_64_bit;
+
+ return dso__data_read_offset(al.map->dso, machine, offset, buf, len);
+}
+
+void thread__free_stitch_list(struct thread *thread)
+{
+ struct lbr_stitch *lbr_stitch = thread->lbr_stitch;
+ struct stitch_list *pos, *tmp;
+
+ if (!lbr_stitch)
+ return;
+
+ list_for_each_entry_safe(pos, tmp, &lbr_stitch->lists, node) {
+ list_del_init(&pos->node);
+ free(pos);
+ }
+
+ list_for_each_entry_safe(pos, tmp, &lbr_stitch->free_lists, node) {
+ list_del_init(&pos->node);
+ free(pos);
+ }
+
+ zfree(&lbr_stitch->prev_lbr_cursor);
+ zfree(&thread->lbr_stitch);
+}
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