platform_system_core/debuggerd/libdebuggerd/backtrace.cpp
Christopher Ferris 4ae266ccbd Add indicator that an elf is memory backed.
Modify the unwinder library to indicate that at least one of the stack
frames contains an elf file that is unreadable.

Modify debuggerd to display a note about the unreadable frame and a possible
way to fix it.

Bug: 129769339

Test: New unit tests pass.
Test: Ran an app that crashes and has an unreadable file and verified the
Test: message is displayed. Then setenforce 0 and verify the message is
Test: not displayed.
Change-Id: Ibc4fe1d117e9b5840290454e90914ddc698d3cc2
2019-04-18 15:37:52 -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 "libdebuggerd/backtrace.h"
#include <errno.h>
#include <dirent.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ptrace.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <map>
#include <memory>
#include <string>
#include <android-base/unique_fd.h>
#include <log/log.h>
#include <unwindstack/Unwinder.h>
#include "libdebuggerd/types.h"
#include "libdebuggerd/utility.h"
static void dump_process_header(log_t* log, pid_t pid, const char* process_name) {
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 (process_name) {
_LOG(log, logtype::BACKTRACE, "Cmd line: %s\n", process_name);
}
_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);
}
void dump_backtrace_thread(int output_fd, unwindstack::Unwinder* unwinder,
const ThreadInfo& thread) {
log_t log;
log.tfd = output_fd;
log.amfd_data = nullptr;
_LOG(&log, logtype::BACKTRACE, "\n\"%s\" sysTid=%d\n", thread.thread_name.c_str(), thread.tid);
unwinder->SetRegs(thread.registers.get());
unwinder->Unwind();
if (unwinder->NumFrames() == 0) {
_LOG(&log, logtype::THREAD, "Unwind failed: tid = %d", thread.tid);
return;
}
log_backtrace(&log, unwinder, " ");
}
void dump_backtrace(android::base::unique_fd output_fd, unwindstack::Unwinder* unwinder,
const std::map<pid_t, ThreadInfo>& thread_info, pid_t target_thread) {
log_t log;
log.tfd = output_fd.get();
log.amfd_data = nullptr;
auto target = thread_info.find(target_thread);
if (target == thread_info.end()) {
ALOGE("failed to find target thread in thread info");
return;
}
dump_process_header(&log, target->second.pid, target->second.process_name.c_str());
dump_backtrace_thread(output_fd.get(), unwinder, target->second);
for (const auto& [tid, info] : thread_info) {
if (tid != target_thread) {
dump_backtrace_thread(output_fd.get(), unwinder, info);
}
}
dump_process_footer(&log, target->second.pid);
}
void dump_backtrace_header(int output_fd) {
log_t log;
log.tfd = output_fd;
log.amfd_data = nullptr;
char process_name[128];
read_with_default("/proc/self/cmdline", process_name, sizeof(process_name), "<unknown>");
dump_process_header(&log, getpid(), process_name);
}
void dump_backtrace_footer(int output_fd) {
log_t log;
log.tfd = output_fd;
log.amfd_data = nullptr;
dump_process_footer(&log, getpid());
}