platform_system_core/debuggerd/backtrace.cpp
Christopher Ferris 99235e9967 Fix problem with wait_for_gdb.
When someone enables wait_for_gdb, activity manager will kill the
stopped process before a developer can attach to the process. To
allow debugging in this case, change the code to only contact the
activity manager right before continuing the process that is
crashing.

Also, modify the conditions under which to do a gdb attach. The previous
code did a partial attach if perform_dump failed. The new version simply
allows an attach regardless of whether perform_dump passes or fails.

Bug: 28409358
(cherry picked from commit 9818bd2bbe)

Change-Id: I42f464b69332748e16b07d9d00f44b3aa26ce8b7
2016-05-05 10:50:39 -07:00

120 lines
3.3 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.
*/
#define LOG_TAG "DEBUG"
#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 <memory>
#include <string>
#include <backtrace/Backtrace.h>
#include <log/log.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, BacktraceMap* map, pid_t pid, pid_t tid) {
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);
std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, tid, map));
if (backtrace->Unwind(0)) {
dump_backtrace_to_log(backtrace.get(), log, " ");
} else {
ALOGE("Unwind failed: tid = %d: %s", tid,
backtrace->GetErrorString(backtrace->GetError()).c_str());
}
}
void dump_backtrace(int fd, BacktraceMap* map, pid_t pid, pid_t tid,
const std::set<pid_t>& siblings, std::string* amfd_data) {
log_t log;
log.tfd = fd;
log.amfd_data = amfd_data;
dump_process_header(&log, pid);
dump_thread(&log, map, pid, tid);
for (pid_t sibling : siblings) {
dump_thread(&log, map, pid, sibling);
}
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());
}
}