platform_system_core/debuggerd/backtrace.c

151 lines
4.6 KiB
C

/*
* 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 <stdbool.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 <corkscrew/backtrace.h>
#include "tombstone.h"
#include "utility.h"
#define STACK_DEPTH 32
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, SCOPE_AT_FAULT, "\n\n----- pid %d at %s -----\n", pid, timestr);
if (procname) {
_LOG(log, SCOPE_AT_FAULT, "Cmd line: %s\n", procname);
}
}
static void dump_process_footer(log_t* log, pid_t pid) {
_LOG(log, SCOPE_AT_FAULT, "\n----- end %d -----\n", pid);
}
static void dump_thread(log_t* log, pid_t tid, ptrace_context_t* context, 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, SCOPE_AT_FAULT, "\n\"%s\" sysTid=%d\n",
threadname ? threadname : "<unknown>", tid);
if (!attached && ptrace(PTRACE_ATTACH, tid, 0, 0) < 0) {
_LOG(log, SCOPE_AT_FAULT, "Could not attach to thread: %s\n", strerror(errno));
return;
}
wait_for_stop(tid, total_sleep_time_usec);
backtrace_frame_t backtrace[STACK_DEPTH];
ssize_t frames = unwind_backtrace_ptrace(tid, context, backtrace, 0, STACK_DEPTH);
if (frames <= 0) {
_LOG(log, SCOPE_AT_FAULT, "Could not obtain stack trace for thread.\n");
} else {
backtrace_symbol_t backtrace_symbols[STACK_DEPTH];
get_backtrace_symbols_ptrace(context, backtrace, frames, backtrace_symbols);
for (size_t i = 0; i < (size_t)frames; i++) {
char line[MAX_BACKTRACE_LINE_LENGTH];
format_backtrace_line(i, &backtrace[i], &backtrace_symbols[i],
line, MAX_BACKTRACE_LINE_LENGTH);
_LOG(log, SCOPE_AT_FAULT, " %s\n", line);
}
free_backtrace_symbols(backtrace_symbols, frames);
}
if (!attached && ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
LOG("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;
log.quiet = true;
ptrace_context_t* context = load_ptrace_context(tid);
dump_process_header(&log, pid);
dump_thread(&log, tid, context, 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, context, false, detach_failed, total_sleep_time_usec);
}
closedir(d);
}
dump_process_footer(&log, pid);
free_ptrace_context(context);
}