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Merge "Compare new unwinder to old unwinder in debuggerd."

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Christopher Ferris 2017-08-12 16:06:48 +00:00 committed by Gerrit Code Review
commit bb2f03f344
4 changed files with 98 additions and 18 deletions
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2
debuggerd/Android.bp
View file

@ -106,6 +106,7 @@ cc_library_static {
"libdebuggerd",
"libbacktrace",
"libunwind",
"libunwindstack",
"liblzma",
"libcutils",
],
@ -171,6 +172,7 @@ cc_library_static {
static_libs: [
"libbacktrace",
"libunwind",
"libunwindstack",
"liblzma",
"libbase",
"libcutils",

10
debuggerd/crash_dump.cpp
View file

@ -329,6 +329,11 @@ int main(int argc, char** argv) {
LOG(FATAL) << "failed to create backtrace map";
}
}
std::unique_ptr<BacktraceMap> backtrace_map_new;
backtrace_map_new.reset(BacktraceMap::CreateNew(main_tid));
if (!backtrace_map_new) {
LOG(FATAL) << "failed to create backtrace map new";
}
// Collect the list of open files.
OpenFilesList open_files;
@ -408,8 +413,9 @@ int main(int argc, char** argv) {
dump_backtrace(output_fd.get(), backtrace_map.get(), target, main_tid, process_name, threads, 0);
} else {
ATRACE_NAME("engrave_tombstone");
engrave_tombstone(output_fd.get(), backtrace_map.get(), &open_files, target, main_tid,
process_name, threads, abort_address, fatal_signal ? &amfd_data : nullptr);
engrave_tombstone(output_fd.get(), backtrace_map.get(), backtrace_map_new.get(), &open_files,
target, main_tid, process_name, threads, abort_address,
fatal_signal ? &amfd_data : nullptr);
}
// We don't actually need to PTRACE_DETACH, as long as our tracees aren't in

8
debuggerd/libdebuggerd/include/tombstone.h
View file

@ -35,10 +35,10 @@ class BacktraceMap;
int open_tombstone(std::string* path);
/* Creates a tombstone file and writes the crash dump to it. */
void engrave_tombstone(int tombstone_fd, BacktraceMap* map, const OpenFilesList* open_files,
pid_t pid, pid_t tid, const std::string& process_name,
const std::map<pid_t, std::string>& threads, uintptr_t abort_msg_address,
std::string* amfd_data);
void engrave_tombstone(int tombstone_fd, BacktraceMap* map, BacktraceMap* map_new,
const OpenFilesList* open_files, pid_t pid, pid_t tid,
const std::string& process_name, const std::map<pid_t, std::string>& threads,
uintptr_t abort_msg_address, std::string* amfd_data);
void engrave_tombstone_ucontext(int tombstone_fd, uintptr_t abort_msg_address, siginfo_t* siginfo,
ucontext_t* ucontext);

96
debuggerd/libdebuggerd/tombstone.cpp
View file

@ -495,8 +495,55 @@ __attribute__((weak)) void dump_registers(log_t* log, const ucontext_t*) {
_LOG(log, logtype::REGISTERS, " register dumping unimplemented on this architecture");
}
static void dump_thread(log_t* log, pid_t pid, pid_t tid, const std::string& process_name,
const std::string& thread_name, BacktraceMap* map,
static bool verify_backtraces_equal(Backtrace* back1, Backtrace* back2) {
if (back1->NumFrames() != back2->NumFrames()) {
return false;
}
std::string back1_str;
std::string back2_str;
for (size_t i = 0; i < back1->NumFrames(); i++) {
back1_str += back1->FormatFrameData(i);
back2_str += back2->FormatFrameData(i);
}
return back1_str == back2_str;
}
static void log_mismatch_data(log_t* log, Backtrace* backtrace) {
_LOG(log, logtype::THREAD, "MISMATCH: This unwind is different.\n");
if (backtrace->NumFrames() == 0) {
_LOG(log, logtype::THREAD, "MISMATCH: No frames in new backtrace.\n");
return;
}
_LOG(log, logtype::THREAD, "MISMATCH: Backtrace from new unwinder.\n");
for (size_t i = 0; i < backtrace->NumFrames(); i++) {
_LOG(log, logtype::THREAD, "MISMATCH: %s\n", backtrace->FormatFrameData(i).c_str());
}
// Get the stack trace up to 8192 bytes.
std::vector<uint64_t> buffer(8192 / sizeof(uint64_t));
size_t bytes =
backtrace->Read(backtrace->GetFrame(0)->sp, reinterpret_cast<uint8_t*>(buffer.data()),
buffer.size() * sizeof(uint64_t));
std::string log_data;
for (size_t i = 0; i < bytes / sizeof(uint64_t); i++) {
if ((i % 4) == 0) {
if (!log_data.empty()) {
_LOG(log, logtype::THREAD, "MISMATCH: stack_data%s\n", log_data.c_str());
log_data = "";
}
}
log_data += android::base::StringPrintf(" 0x%016" PRIx64, buffer[i]);
}
if (!log_data.empty()) {
_LOG(log, logtype::THREAD, "MISMATCH: data%s\n", log_data.c_str());
}
// If there is any leftover (bytes % sizeof(uint64_t) != 0, ignore it for now.
}
static bool dump_thread(log_t* log, pid_t pid, pid_t tid, const std::string& process_name,
const std::string& thread_name, BacktraceMap* map, BacktraceMap* map_new,
uintptr_t abort_msg_address, bool primary_thread) {
log->current_tid = tid;
if (!primary_thread) {
@ -510,7 +557,18 @@ static void dump_thread(log_t* log, pid_t pid, pid_t tid, const std::string& pro
dump_abort_message(backtrace.get(), log, abort_msg_address);
}
dump_registers(log, tid);
bool matches = true;
if (backtrace->Unwind(0)) {
// Use the new method and verify it is the same as old.
std::unique_ptr<Backtrace> backtrace_new(Backtrace::CreateNew(pid, tid, map_new));
if (!backtrace_new->Unwind(0)) {
_LOG(log, logtype::THREAD, "Failed to unwind with new unwinder: %s\n",
backtrace_new->GetErrorString(backtrace_new->GetError()).c_str());
matches = false;
} else if (!verify_backtraces_equal(backtrace.get(), backtrace_new.get())) {
log_mismatch_data(log, backtrace_new.get());
matches = false;
}
dump_backtrace_and_stack(backtrace.get(), log);
} else {
ALOGE("Unwind failed: pid = %d, tid = %d", pid, tid);
@ -524,6 +582,8 @@ static void dump_thread(log_t* log, pid_t pid, pid_t tid, const std::string& pro
}
log->current_tid = log->crashed_tid;
return matches;
}
// Reads the contents of the specified log device, filters out the entries
@ -657,9 +717,10 @@ static void dump_logs(log_t* log, pid_t pid, unsigned int tail) {
}
// Dumps all information about the specified pid to the tombstone.
static void dump_crash(log_t* log, BacktraceMap* map, const OpenFilesList* open_files, pid_t pid,
pid_t tid, const std::string& process_name,
const std::map<pid_t, std::string>& threads, uintptr_t abort_msg_address) {
static void dump_crash(log_t* log, BacktraceMap* map, BacktraceMap* map_new,
const OpenFilesList* open_files, pid_t pid, pid_t tid,
const std::string& process_name, const std::map<pid_t, std::string>& threads,
uintptr_t abort_msg_address) {
// don't copy log messages to tombstone unless this is a dev device
char value[PROPERTY_VALUE_MAX];
property_get("ro.debuggable", value, "0");
@ -668,7 +729,8 @@ static void dump_crash(log_t* log, BacktraceMap* map, const OpenFilesList* open_
_LOG(log, logtype::HEADER,
"*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n");
dump_header_info(log);
dump_thread(log, pid, tid, process_name, threads.find(tid)->second, map, abort_msg_address, true);
bool new_unwind_matches = dump_thread(log, pid, tid, process_name, threads.find(tid)->second, map,
map_new, abort_msg_address, true);
if (want_logs) {
dump_logs(log, pid, 5);
}
@ -678,7 +740,9 @@ static void dump_crash(log_t* log, BacktraceMap* map, const OpenFilesList* open_
const std::string& thread_name = it.second;
if (thread_tid != tid) {
dump_thread(log, pid, thread_tid, process_name, thread_name, map, 0, false);
bool match =
dump_thread(log, pid, thread_tid, process_name, thread_name, map, map_new, 0, false);
new_unwind_matches = new_unwind_matches && match;
}
}
@ -690,6 +754,14 @@ static void dump_crash(log_t* log, BacktraceMap* map, const OpenFilesList* open_
if (want_logs) {
dump_logs(log, pid, 0);
}
if (!new_unwind_matches) {
_LOG(log, logtype::THREAD, "MISMATCH: New and old unwinder do not agree.\n");
_LOG(log, logtype::THREAD, "MISMATCH: If you see this please file a bug in:\n");
_LOG(log, logtype::THREAD,
"MISMATCH: Android > Android OS & Apps > Runtime > native > tools "
"(debuggerd/gdb/init/simpleperf/strace/valgrind)\n");
_LOG(log, logtype::THREAD, "MISMATCH: and attach this tombstone.\n");
}
}
// open_tombstone - find an available tombstone slot, if any, of the
@ -745,16 +817,16 @@ int open_tombstone(std::string* out_path) {
return fd;
}
void engrave_tombstone(int tombstone_fd, BacktraceMap* map, const OpenFilesList* open_files,
pid_t pid, pid_t tid, const std::string& process_name,
const std::map<pid_t, std::string>& threads, uintptr_t abort_msg_address,
std::string* amfd_data) {
void engrave_tombstone(int tombstone_fd, BacktraceMap* map, BacktraceMap* map_new,
const OpenFilesList* open_files, pid_t pid, pid_t tid,
const std::string& process_name, const std::map<pid_t, std::string>& threads,
uintptr_t abort_msg_address, std::string* amfd_data) {
log_t log;
log.current_tid = tid;
log.crashed_tid = tid;
log.tfd = tombstone_fd;
log.amfd_data = amfd_data;
dump_crash(&log, map, open_files, pid, tid, process_name, threads, abort_msg_address);
dump_crash(&log, map, map_new, open_files, pid, tid, process_name, threads, abort_msg_address);
}
void engrave_tombstone_ucontext(int tombstone_fd, uintptr_t abort_msg_address, siginfo_t* siginfo,