![Jiri Olsa](/assets/img/avatar_default.png)
Currently we call unwind__prepare_access for map event. In case we report fork event the thread inherits its parent's maps and unwind__prepare_access is never called for the thread. This causes unwind__get_entries seeing uninitialized unwind_libunwind_ops and thus returning no callchain. Adding unwind__prepare_access calls for fork even processing. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1467634583-29147-5-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
317 lines
6.4 KiB
C
317 lines
6.4 KiB
C
#include "../perf.h"
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include "session.h"
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#include "thread.h"
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#include "thread-stack.h"
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#include "util.h"
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#include "debug.h"
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#include "comm.h"
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#include "unwind.h"
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#include <api/fs/fs.h>
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int thread__init_map_groups(struct thread *thread, struct machine *machine)
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{
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struct thread *leader;
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pid_t pid = thread->pid_;
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if (pid == thread->tid || pid == -1) {
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thread->mg = map_groups__new(machine);
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} else {
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leader = __machine__findnew_thread(machine, pid, pid);
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if (leader) {
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thread->mg = map_groups__get(leader->mg);
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thread__put(leader);
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}
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}
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return thread->mg ? 0 : -1;
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}
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struct thread *thread__new(pid_t pid, pid_t tid)
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{
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char *comm_str;
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struct comm *comm;
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struct thread *thread = zalloc(sizeof(*thread));
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if (thread != NULL) {
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thread->pid_ = pid;
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thread->tid = tid;
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thread->ppid = -1;
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thread->cpu = -1;
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INIT_LIST_HEAD(&thread->comm_list);
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comm_str = malloc(32);
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if (!comm_str)
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goto err_thread;
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snprintf(comm_str, 32, ":%d", tid);
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comm = comm__new(comm_str, 0, false);
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free(comm_str);
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if (!comm)
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goto err_thread;
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list_add(&comm->list, &thread->comm_list);
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atomic_set(&thread->refcnt, 1);
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RB_CLEAR_NODE(&thread->rb_node);
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}
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return thread;
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err_thread:
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free(thread);
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return NULL;
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}
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void thread__delete(struct thread *thread)
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{
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struct comm *comm, *tmp;
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BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
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thread_stack__free(thread);
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if (thread->mg) {
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map_groups__put(thread->mg);
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thread->mg = NULL;
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}
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list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
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list_del(&comm->list);
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comm__free(comm);
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}
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unwind__finish_access(thread);
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free(thread);
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}
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struct thread *thread__get(struct thread *thread)
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{
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if (thread)
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atomic_inc(&thread->refcnt);
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return thread;
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}
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void thread__put(struct thread *thread)
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{
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if (thread && atomic_dec_and_test(&thread->refcnt)) {
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/*
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* Remove it from the dead_threads list, as last reference
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* is gone.
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*/
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list_del_init(&thread->node);
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thread__delete(thread);
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}
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}
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struct comm *thread__comm(const struct thread *thread)
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{
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if (list_empty(&thread->comm_list))
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return NULL;
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return list_first_entry(&thread->comm_list, struct comm, list);
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}
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struct comm *thread__exec_comm(const struct thread *thread)
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{
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struct comm *comm, *last = NULL;
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list_for_each_entry(comm, &thread->comm_list, list) {
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if (comm->exec)
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return comm;
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last = comm;
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}
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return last;
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}
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int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
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bool exec)
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{
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struct comm *new, *curr = thread__comm(thread);
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int err;
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/* Override the default :tid entry */
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if (!thread->comm_set) {
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err = comm__override(curr, str, timestamp, exec);
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if (err)
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return err;
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} else {
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new = comm__new(str, timestamp, exec);
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if (!new)
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return -ENOMEM;
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list_add(&new->list, &thread->comm_list);
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if (exec)
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unwind__flush_access(thread);
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}
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thread->comm_set = true;
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return 0;
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}
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int thread__set_comm_from_proc(struct thread *thread)
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{
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char path[64];
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char *comm = NULL;
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size_t sz;
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int err = -1;
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if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
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thread->pid_, thread->tid) >= (int)sizeof(path)) &&
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procfs__read_str(path, &comm, &sz) == 0) {
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comm[sz - 1] = '\0';
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err = thread__set_comm(thread, comm, 0);
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}
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return err;
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}
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const char *thread__comm_str(const struct thread *thread)
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{
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const struct comm *comm = thread__comm(thread);
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if (!comm)
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return NULL;
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return comm__str(comm);
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}
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/* CHECKME: it should probably better return the max comm len from its comm list */
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int thread__comm_len(struct thread *thread)
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{
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if (!thread->comm_len) {
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const char *comm = thread__comm_str(thread);
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if (!comm)
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return 0;
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thread->comm_len = strlen(comm);
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}
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return thread->comm_len;
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}
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size_t thread__fprintf(struct thread *thread, FILE *fp)
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{
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return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
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map_groups__fprintf(thread->mg, fp);
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}
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int thread__insert_map(struct thread *thread, struct map *map)
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{
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int ret;
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ret = unwind__prepare_access(thread, map, NULL);
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if (ret)
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return ret;
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map_groups__fixup_overlappings(thread->mg, map, stderr);
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map_groups__insert(thread->mg, map);
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return 0;
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}
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static int __thread__prepare_access(struct thread *thread)
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{
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bool initialized = false;
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int i, err = 0;
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for (i = 0; i < MAP__NR_TYPES; ++i) {
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struct maps *maps = &thread->mg->maps[i];
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struct map *map;
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pthread_rwlock_rdlock(&maps->lock);
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for (map = maps__first(maps); map; map = map__next(map)) {
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err = unwind__prepare_access(thread, map, &initialized);
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if (err || initialized)
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break;
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}
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pthread_rwlock_unlock(&maps->lock);
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}
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return err;
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}
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static int thread__prepare_access(struct thread *thread)
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{
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int err = 0;
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if (symbol_conf.use_callchain)
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err = __thread__prepare_access(thread);
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return err;
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}
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static int thread__clone_map_groups(struct thread *thread,
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struct thread *parent)
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{
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int i;
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/* This is new thread, we share map groups for process. */
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if (thread->pid_ == parent->pid_)
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return thread__prepare_access(thread);
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if (thread->mg == parent->mg) {
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pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
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thread->pid_, thread->tid, parent->pid_, parent->tid);
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return 0;
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}
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/* But this one is new process, copy maps. */
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for (i = 0; i < MAP__NR_TYPES; ++i)
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if (map_groups__clone(thread, parent->mg, i) < 0)
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return -ENOMEM;
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return 0;
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}
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int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
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{
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int err;
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if (parent->comm_set) {
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const char *comm = thread__comm_str(parent);
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if (!comm)
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return -ENOMEM;
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err = thread__set_comm(thread, comm, timestamp);
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if (err)
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return err;
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}
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thread->ppid = parent->tid;
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return thread__clone_map_groups(thread, parent);
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}
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void thread__find_cpumode_addr_location(struct thread *thread,
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enum map_type type, u64 addr,
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struct addr_location *al)
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{
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size_t i;
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const u8 cpumodes[] = {
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PERF_RECORD_MISC_USER,
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PERF_RECORD_MISC_KERNEL,
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PERF_RECORD_MISC_GUEST_USER,
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PERF_RECORD_MISC_GUEST_KERNEL
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};
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for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
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thread__find_addr_location(thread, cpumodes[i], type, addr, al);
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if (al->map)
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break;
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}
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}
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struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
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{
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if (thread->pid_ == thread->tid)
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return thread__get(thread);
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if (thread->pid_ == -1)
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return NULL;
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return machine__find_thread(machine, thread->pid_, thread->pid_);
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}
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