summaryrefslogtreecommitdiffstats
path: root/debuggerd/backtrace.cpp
blob: c2a1dbc1c881fca903d915a31c2dc31de0f6649f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <limits.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ptrace.h>

#include <backtrace/Backtrace.h>
#include <UniquePtr.h>

#include "backtrace.h"

#include "utility.h"

static void dump_process_header(log_t* log, pid_t pid) {
  char path[PATH_MAX];
  char procnamebuf[1024];
  char* procname = NULL;
  FILE* fp;

  snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
  if ((fp = fopen(path, "r"))) {
    procname = fgets(procnamebuf, sizeof(procnamebuf), fp);
    fclose(fp);
  }

  time_t t = time(NULL);
  struct tm tm;
  localtime_r(&t, &tm);
  char timestr[64];
  strftime(timestr, sizeof(timestr), "%F %T", &tm);
  _LOG(log, logtype::BACKTRACE, "\n\n----- pid %d at %s -----\n", pid, timestr);

  if (procname) {
    _LOG(log, logtype::BACKTRACE, "Cmd line: %s\n", procname);
  }
  _LOG(log, logtype::BACKTRACE, "ABI: '%s'\n", ABI_STRING);
}

static void dump_process_footer(log_t* log, pid_t pid) {
  _LOG(log, logtype::BACKTRACE, "\n----- end %d -----\n", pid);
}

static void dump_thread(
    log_t* log, pid_t tid, bool attached, bool* detach_failed, int* total_sleep_time_usec) {
  char path[PATH_MAX];
  char threadnamebuf[1024];
  char* threadname = NULL;
  FILE* fp;

  snprintf(path, sizeof(path), "/proc/%d/comm", tid);
  if ((fp = fopen(path, "r"))) {
    threadname = fgets(threadnamebuf, sizeof(threadnamebuf), fp);
    fclose(fp);
    if (threadname) {
      size_t len = strlen(threadname);
      if (len && threadname[len - 1] == '\n') {
          threadname[len - 1] = '\0';
      }
    }
  }

  _LOG(log, logtype::BACKTRACE, "\n\"%s\" sysTid=%d\n", threadname ? threadname : "<unknown>", tid);

  if (!attached && ptrace(PTRACE_ATTACH, tid, 0, 0) < 0) {
    _LOG(log, logtype::BACKTRACE, "Could not attach to thread: %s\n", strerror(errno));
    return;
  }

  if (!attached && wait_for_sigstop(tid, total_sleep_time_usec, detach_failed) == -1) {
    return;
  }

  UniquePtr<Backtrace> backtrace(Backtrace::Create(tid, BACKTRACE_CURRENT_THREAD));
  if (backtrace->Unwind(0)) {
    dump_backtrace_to_log(backtrace.get(), log, "  ");
  }

  if (!attached && ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
    _LOG(log, logtype::ERROR, "ptrace detach from %d failed: %s\n", tid, strerror(errno));
    *detach_failed = true;
  }
}

void dump_backtrace(int fd, int amfd, pid_t pid, pid_t tid, bool* detach_failed,
                    int* total_sleep_time_usec) {
  log_t log;
  log.tfd = fd;
  log.amfd = amfd;

  dump_process_header(&log, pid);
  dump_thread(&log, tid, true, detach_failed, total_sleep_time_usec);

  char task_path[64];
  snprintf(task_path, sizeof(task_path), "/proc/%d/task", pid);
  DIR* d = opendir(task_path);
  if (d != NULL) {
    struct dirent* de = NULL;
    while ((de = readdir(d)) != NULL) {
      if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..")) {
        continue;
      }

      char* end;
      pid_t new_tid = strtoul(de->d_name, &end, 10);
      if (*end || new_tid == tid) {
        continue;
      }

      dump_thread(&log, new_tid, false, detach_failed, total_sleep_time_usec);
    }
    closedir(d);
  }

  dump_process_footer(&log, pid);
}

void dump_backtrace_to_log(Backtrace* backtrace, log_t* log, const char* prefix) {
  for (size_t i = 0; i < backtrace->NumFrames(); i++) {
    _LOG(log, logtype::BACKTRACE, "%s%s\n", prefix, backtrace->FormatFrameData(i).c_str());
  }
}