dmnt: add attach support to gdbstub

This commit is contained in:
Michael Scire 2021-07-18 23:22:44 -07:00
parent 22bce9f680
commit 74ca199c94
3 changed files with 507 additions and 19 deletions

View file

@ -25,6 +25,7 @@ namespace ams::dmnt {
constexpr size_t ServerThreadStackSize = util::AlignUp(4 * GdbPacketBufferSize + os::MemoryPageSize, os::ThreadStackAlignment);
alignas(os::ThreadStackAlignment) constinit u8 g_server_thread_stack[ServerThreadStackSize];
alignas(os::ThreadStackAlignment) constinit u8 g_events_thread_stack[16_KB];
constinit os::ThreadType g_server_thread;
@ -68,7 +69,7 @@ namespace ams::dmnt {
{
/* Create gdb server for the socket. */
util::ConstructAt(g_gdb_server, client_fd);
util::ConstructAt(g_gdb_server, client_fd, g_events_thread_stack, sizeof(g_events_thread_stack));
ON_SCOPE_EXIT { util::DestroyAt(g_gdb_server); };
/* Process for the server. */

View file

@ -20,13 +20,11 @@
namespace ams::dmnt {
namespace {
constexpr const char TargetXmlAarch64[] =
"l<?xml version=\"1.0\"?>"
"<!DOCTYPE target SYSTEM \"gdb-target.dtd\">"
"<target>"
"<architecture>aarch64</architecture>"
"<osabi>GNU/Linux</osabi>"
"<xi:include href=\"aarch64-core.xml\"/>"
"<xi:include href=\"aarch64-fpu.xml\"/>"
"</target>";
@ -299,6 +297,34 @@ namespace ams::dmnt {
}
}
constexpr u64 DecodeHex(const char *s) {
u64 value = 0;
while (true) {
const char c = *(s++);
if (int v = DecodeHex(c); v >= 0) {
value <<= 4;
value |= v & 0xF;
} else {
break;
}
}
return value;
}
void MemoryToHex(char *dst, const void *mem, size_t size) {
const u8 *mem_u8 = static_cast<const u8 *>(mem);
while (size-- > 0) {
const u8 v = *(mem_u8++);
*(dst++) = "0123456789abcdef"[v >> 4];
*(dst++) = "0123456789abcdef"[v & 0xF];
}
*dst = 0;
}
void ParseOffsetLength(const char *packet, u32 &offset, u32 &length) {
/* Default to zero. */
offset = 0;
@ -325,11 +351,194 @@ namespace ams::dmnt {
constinit char g_process_list_buffer[0x2000];
constinit os::SdkMutex g_event_request_lock;
constinit os::SdkMutex g_event_lock;
constinit os::SdkConditionVariable g_event_request_cv;
constinit os::SdkConditionVariable g_event_done_cv;
}
GdbServerImpl::GdbServerImpl(int socket) : m_socket(socket), m_session(socket), m_packet_io() { /* ... */ }
GdbServerImpl::GdbServerImpl(int socket, void *stack, size_t stack_size) : m_socket(socket), m_session(socket), m_packet_io(), m_state(State::Initial), m_event(os::EventClearMode_AutoClear) {
/* Create and start the events thread. */
R_ABORT_UNLESS(os::CreateThread(std::addressof(m_events_thread), DebugEventsThreadEntry, this, stack, stack_size, os::HighestThreadPriority - 1));
os::StartThread(std::addressof(m_events_thread));
GdbServerImpl::~GdbServerImpl() { /* ... */ }
/* Set our state. */
m_state = State::Running;
}
GdbServerImpl::~GdbServerImpl() {
/* Set ourselves as killed. */
m_killed = true;
/* Signal to our events thread. */
{
std::scoped_lock lk(g_event_request_lock);
g_event_request_cv.Signal();
}
/* Signal our event. */
m_event.Signal();
/* Wait for our thread to finish. */
os::WaitThread(std::addressof(m_events_thread));
os::DestroyThread(std::addressof(m_events_thread));
/* Clear our state. */
m_state = State::Destroyed;
/* Detach. */
if (m_attached) {
R_ABORT_UNLESS(svc::CloseHandle(m_debug_handle));
}
}
void GdbServerImpl::DebugEventsThread() {
/* Process events. */
{
std::scoped_lock lk(g_event_lock);
/* Loop while we're not killed. */
while (!m_killed) {
/* Wait for a request to come in. */
g_event_request_cv.Wait(g_event_lock);
/* Check that we're not killed now. */
if (m_killed) {
break;
}
/* Set ourselves as unattached. */
m_attached = false;
/* If we have a process id, attach. */
if (R_FAILED(svc::DebugActiveProcess(std::addressof(m_debug_handle), m_process_id.value))) {
AMS_DMNT2_GDB_LOG_DEBUG("Failed to attach to %016lx\n", m_process_id.value);
m_debug_handle = svc::InvalidHandle;
g_event_done_cv.Signal();
continue;
}
/* Get the process id. */
if (R_FAILED(svc::GetProcessId(std::addressof(m_process_id.value), m_debug_handle))) {
AMS_DMNT2_GDB_LOG_DEBUG("Failed to get process id for debug handle\n");
R_ABORT_UNLESS(svc::CloseHandle(m_debug_handle));
m_debug_handle = svc::InvalidHandle;
g_event_done_cv.Signal();
continue;
}
/* Set ourselves as attached. */
m_attached = true;
/* Get the create process event. */
{
svc::DebugEventInfo d;
R_ABORT_UNLESS(svc::GetDebugEvent(std::addressof(d), m_debug_handle));
AMS_ABORT_UNLESS(d.type == svc::DebugEvent_CreateProcess);
m_create_process_info = d.info.create_process;
}
/* Signal that we're done attaching. */
g_event_done_cv.Signal();
/* Process debug events without the lock held. */
{
g_event_lock.Unlock();
this->ProcessDebugEvents();
g_event_lock.Lock();
}
/* Clear our process ids. */
m_process_id = os::InvalidProcessId;
m_target_process_id = os::InvalidProcessId;
}
}
/* Set our state. */
m_state = State::Exited;
}
void GdbServerImpl::ProcessDebugEvents() {
AMS_DMNT2_GDB_LOG_DEBUG("Processing debug events for %016lx\n", m_process_id.value);
while (true) {
/* Wait for an event to come in. */
const Result wait_result = [&] ALWAYS_INLINE_LAMBDA {
std::scoped_lock lk(g_event_lock);
s32 dummy = -1;
return svc::WaitSynchronization(std::addressof(dummy), std::addressof(m_debug_handle), 1, TimeSpan::FromMilliSeconds(20).GetNanoSeconds());
}();
/* Check if we're killed. */
if (m_killed) {
break;
}
/* If we didn't get an event, try again. */
if (svc::ResultTimedOut::Includes(wait_result)) {
continue;
}
/* Try to get the event. */
svc::DebugEventInfo d;
if (R_FAILED(svc::GetDebugEvent(std::addressof(d), m_debug_handle))) {
continue;
}
/* Process the event. */
switch (d.type) {
default:
AMS_DMNT2_GDB_LOG_DEBUG("Unhandled ProcessEvent %u\n", static_cast<u32>(d.type));
break;
}
}
}
void GdbServerImpl::SetStopReplyPacket(GdbSignal signal) {
/* Set the signal. */
SetReply(m_reply_packet, "T%02X", static_cast<u32>(signal));
/* Get the thread context. */
svc::ThreadContext thread_context = {};
svc::GetDebugThreadContext(std::addressof(thread_context), m_debug_handle, m_thread_id, svc::ThreadContextFlag_General | svc::ThreadContextFlag_Control);
/* Add important registers. */
/* TODO: aarch32 */
{
if (thread_context.fp != 0) {
AppendReply(m_reply_packet, "1d:%016lx", util::ConvertToBigEndian(thread_context.fp));
} else {
AppendReply(m_reply_packet, "1d:0*,");
}
if (thread_context.sp != 0) {
AppendReply(m_reply_packet, ";1f:%016lx", util::ConvertToBigEndian(thread_context.sp));
} else {
AppendReply(m_reply_packet, ";1f:0*,");
}
if (thread_context.pc != 0) {
AppendReply(m_reply_packet, ";20:%016lx", util::ConvertToBigEndian(thread_context.pc));
} else {
AppendReply(m_reply_packet, ";20:0*,");
}
}
/* Add the thread id. */
AppendReply(m_reply_packet, ";thread:p%lx.%lx", m_target_process_id.value, m_thread_id);
/* Add the thread core. */
{
u64 dummy;
u32 core = 0;
svc::GetDebugThreadParam(std::addressof(dummy), std::addressof(core), m_debug_handle, m_thread_id, svc::DebugThreadParam_CurrentCore);
AppendReply(m_reply_packet, ";core:%u;", core);
}
}
void GdbServerImpl::LoopProcess() {
/* Process packets. */
@ -366,6 +575,17 @@ namespace ams::dmnt {
case 'H':
this->H();
break;
case 'g':
if (!this->g()) {
m_killed = true;
}
break;
case 'm':
this->m();
break;
case 'v':
this->v();
break;
case 'q':
this->q();
break;
@ -383,8 +603,164 @@ namespace ams::dmnt {
void GdbServerImpl::H() {
if (this->HasDebugProcess()) {
/* TODO */
if (ParsePrefix(m_receive_packet, "Hg") || ParsePrefix(m_receive_packet, "HG")) {
this->Hg();
} else {
SetReplyError(m_reply_packet, "E01");
}
} else {
SetReplyError(m_reply_packet, "E01");
}
}
void GdbServerImpl::Hg() {
if (const char *dot = std::strchr(m_receive_packet, '.'); dot != nullptr) {
m_thread_id = DecodeHex(dot + 1);
AMS_DMNT2_GDB_LOG_DEBUG("Set thread id = %lx\n", m_thread_id);
/* TODO: Validate thread exists for the process? */
}
SetReplyOk(m_reply_packet);
}
bool GdbServerImpl::g() {
/* TODO: aarch32 */
/* Get thread context. */
svc::ThreadContext thread_context;
if (R_FAILED(svc::GetDebugThreadContext(std::addressof(thread_context), m_debug_handle, m_thread_id, svc::ThreadContextFlag_All))) {
return false;
}
/* Copy general purpose registers. */
for (size_t i = 0; i < util::size(thread_context.r); ++i) {
if (thread_context.r[i] != 0) {
AppendReply(m_reply_packet, "%016lx", util::ConvertToBigEndian(thread_context.r[i]));
} else {
AppendReply(m_reply_packet, "0*,");
}
}
/* Copy special registers. */
if (thread_context.fp != 0) {
AppendReply(m_reply_packet, "%016lx", util::ConvertToBigEndian(thread_context.fp));
} else {
AppendReply(m_reply_packet, "0*,");
}
if (thread_context.lr != 0) {
AppendReply(m_reply_packet, "%016lx", util::ConvertToBigEndian(thread_context.lr));
} else {
AppendReply(m_reply_packet, "0*,");
}
if (thread_context.sp != 0) {
AppendReply(m_reply_packet, "%016lx", util::ConvertToBigEndian(thread_context.sp));
} else {
AppendReply(m_reply_packet, "0*,");
}
if (thread_context.pc != 0) {
AppendReply(m_reply_packet, "%016lx", util::ConvertToBigEndian(thread_context.pc));
} else {
AppendReply(m_reply_packet, "0*,");
}
if (thread_context.pstate != 0) {
AppendReply(m_reply_packet, "%08x", util::ConvertToBigEndian(thread_context.pstate));
} else {
AppendReply(m_reply_packet, "0*\"0");
}
/* Copy FPU registers. */
for (size_t i = 0; i < util::size(thread_context.v); ++i) {
if (thread_context.v[i] != 0) {
AppendReply(m_reply_packet, "%016lx%016lx", util::ConvertToBigEndian(static_cast<u64>(thread_context.v[i] >> 0)), util::ConvertToBigEndian(static_cast<u64>(thread_context.v[i] >> BITSIZEOF(u64))));
} else {
AppendReply(m_reply_packet, "0*<");
}
}
return true;
}
void GdbServerImpl::m() {
++m_receive_packet;
/* Validate format. */
const char *comma = std::strchr(m_receive_packet, ',');
if (comma == nullptr) {
SetReplyError(m_reply_packet, "E01");
return;
}
/* Parse address/length. */
const u64 address = DecodeHex(m_receive_packet);
const u64 length = DecodeHex(comma + 1);
if (length >= sizeof(m_buffer)) {
SetReplyError(m_reply_packet, "E01");
return;
}
/* Read the memory. */
/* TODO: Detect partial readability? */
if (R_FAILED(svc::ReadDebugProcessMemory(reinterpret_cast<uintptr_t>(m_buffer), m_debug_handle, address, length))) {
SetReplyError(m_reply_packet, "E01");
return;
}
/* Encode the memory. */
MemoryToHex(m_reply_packet, m_buffer, length);
}
void GdbServerImpl::v() {
if (ParsePrefix(m_receive_packet, "vAttach;")) {
this->vAttach();
} else {
AMS_DMNT2_GDB_LOG_DEBUG("Not Implemented v: %s\n", m_receive_packet);
}
}
void GdbServerImpl::vAttach() {
if (!this->HasDebugProcess()) {
/* Get the process id. */
if (const u64 process_id = DecodeHex(m_receive_packet); process_id != 0) {
/* Set our process id. */
m_process_id = { process_id };
m_target_process_id = { process_id };
/* Wait for us to be attached. */
bool attached;
{
std::scoped_lock lk(g_event_request_lock);
g_event_request_cv.Signal();
if (!g_event_done_cv.TimedWait(g_event_request_lock, TimeSpan::FromSeconds(2))) {
m_event.Signal();
}
attached = m_attached;
}
/* If we're attached, send a stop reply packet. */
if (attached) {
/* Set our initial thread id. */
{
s32 dummy;
u64 thread_id = 0;
R_ABORT_UNLESS(svc::GetThreadList(std::addressof(dummy), std::addressof(thread_id), 1, m_debug_handle));
m_thread_id = thread_id;
}
/* Set the stop reply packet. */
this->SetStopReplyPacket(GdbSignal_Signal0);
} else {
SetReplyError(m_reply_packet, "E01");
}
} else {
SetReplyError(m_reply_packet, "E01");
}
} else {
SetReplyError(m_reply_packet, "E01");
}
@ -406,7 +782,11 @@ namespace ams::dmnt {
void GdbServerImpl::qAttached() {
if (this->HasDebugProcess()) {
/* TODO: Parse/Save the requested process id */
/* Parse/Save the requested process id */
if (const char *colon = std::strchr(m_receive_packet, ':'); colon != nullptr) {
m_target_process_id.value = DecodeHex(colon + 1);
AMS_DMNT2_GDB_LOG_DEBUG("Queried for attached to %016lx\n", m_target_process_id.value);
}
SetReply(m_reply_packet, "1");
} else {
SetReplyError(m_reply_packet, "E01");
@ -415,8 +795,20 @@ namespace ams::dmnt {
void GdbServerImpl::qC() {
if (this->HasDebugProcess()) {
/* TODO */
SetReplyError(m_reply_packet, "E01");
/* Potentially get our thread id. */
if (m_thread_id == 0) {
s32 dummy;
u64 thread_id = 0;
if (R_FAILED(svc::GetThreadList(std::addressof(dummy), std::addressof(thread_id), 1, m_debug_handle))) {
SetReplyError(m_reply_packet, "E01");
return;
}
m_thread_id = thread_id;
}
/* Send the thread id. */
SetReply(m_reply_packet, "QCp%lx.%lx", m_target_process_id.value, m_thread_id);
} else {
SetReplyError(m_reply_packet, "E01");
}
@ -430,10 +822,12 @@ namespace ams::dmnt {
AppendReply(m_reply_packet, ";multiprocess+");
AppendReply(m_reply_packet, ";qXfer:osdata:read+");
AppendReply(m_reply_packet, ";qXfer:features:read+");
AppendReply(m_reply_packet, ";qXfer:libraries:read+");
AppendReply(m_reply_packet, ";qXfer:libraries-svr4:read+");
AppendReply(m_reply_packet, ";augmented-libraries-svr4-read+");
AppendReply(m_reply_packet, ";qXfer:threads:read+");
AppendReply(m_reply_packet, ";swbreak+");
AppendReply(m_reply_packet, ";hwbreak+");
AppendReply(m_reply_packet, ";vContSupported+");
}
void GdbServerImpl::qXfer() {
@ -450,6 +844,11 @@ namespace ams::dmnt {
/* Process. */
if (ParsePrefix(m_receive_packet, "features:read:")) {
this->qXferFeaturesRead();
} else if (ParsePrefix(m_receive_packet, "threads:read:")) {
if (!this->qXferThreadsRead()) {
m_killed = true;
SetReplyError(m_reply_packet, "E01");
}
} else {
AMS_DMNT2_GDB_LOG_DEBUG("Not Implemented qxfer: %s\n", m_receive_packet);
SetReplyError(m_reply_packet, "E01");
@ -539,13 +938,10 @@ namespace ams::dmnt {
/* Get the create process event. */
svc::DebugEventInfo d;
while (true) {
R_ABORT_UNLESS(svc::GetDebugEvent(std::addressof(d), handle));
if (d.type == svc::DebugEvent_CreateProcess) {
AppendReply(g_process_list_buffer, "<item>\n<column name=\"pid\">%lu</column>\n<column name=\"command\">%s</column>\n</item>\n", d.info.create_process.process_id, d.info.create_process.name);
break;
}
}
R_ABORT_UNLESS(svc::GetDebugEvent(std::addressof(d), handle));
AMS_ABORT_UNLESS(d.type == svc::DebugEvent_CreateProcess);
AppendReply(g_process_list_buffer, "<item>\n<column name=\"pid\">%lu</column>\n<column name=\"command\">%s</column>\n</item>\n", d.info.create_process.process_id, d.info.create_process.name);
}
}
}
@ -577,6 +973,51 @@ namespace ams::dmnt {
}
}
bool GdbServerImpl::qXferThreadsRead() {
/* Set header. */
SetReply(m_reply_packet, "l<threads>");
/* Get thread list. */
s32 num_threads;
u64 thread_ids[0x80];
if (R_FAILED(svc::GetThreadList(std::addressof(num_threads), thread_ids, util::size(thread_ids), m_debug_handle))) {
return false;
}
/* Cap thread limit at 128. */
if (num_threads > 0x80) {
num_threads = 0x80;
}
/* Add all threads. */
for (s32 i = 0; i < num_threads; ++i) {
const auto thread_id = thread_ids[num_threads - 1 - i];
/* Check that we can get the thread context. */
svc::ThreadContext thread_context;
if (R_FAILED(svc::GetDebugThreadContext(std::addressof(thread_context), m_debug_handle, thread_id, svc::ThreadContextFlag_All))) {
continue;
}
/* Get the thread core. */
u32 core = 0;
{
u64 dummy;
u32 val32;
if (R_SUCCEEDED(svc::GetDebugThreadParam(std::addressof(dummy), std::addressof(val32), m_debug_handle, m_thread_id, svc::DebugThreadParam_CurrentCore))) {
core = val32;
}
}
/* TODO: `name=\"%s\"`? */
AppendReply(m_reply_packet, "<thread id=\"p%lx.%lx\" core=\"%u\"/>", m_target_process_id.value, thread_id, core);
}
AppendReply(m_reply_packet, "</threads>");
return true;
}
void GdbServerImpl::QuestionMark() {
/* TODO */
AMS_DMNT2_GDB_LOG_DEBUG("Not Implemented QuestionMark\n");

View file

@ -20,6 +20,26 @@
namespace ams::dmnt {
class GdbServerImpl {
private:
enum class State {
Initial,
Running,
Exited,
Destroyed,
};
enum GdbSignal {
GdbSignal_Signal0 = 0,
GdbSignal_Interrupt = 2,
GdbSignal_IllegalInstruction = 4,
GdbSignal_BreakpointTrap = 5,
GdbSignal_EmulationTrap = 7,
GdbSignal_ArithmeticException = 8,
GdbSignal_Killed = 9,
GdbSignal_BusError = 10,
GdbSignal_SegmentationFault = 11,
GdbSignal_BadSystemCall = 12,
};
private:
int m_socket;
HtcsSession m_session;
@ -27,9 +47,18 @@ namespace ams::dmnt {
char *m_receive_packet{nullptr};
char *m_reply_packet{nullptr};
char m_buffer[GdbPacketBufferSize / 2];
bool m_killed{false};
svc::Handle m_debug_handle{svc::InvalidHandle};
os::ThreadType m_events_thread;
State m_state;
bool m_attached{false};
u64 m_thread_id{0};
os::ProcessId m_process_id{os::InvalidProcessId};
os::ProcessId m_target_process_id{os::InvalidProcessId};
svc::DebugInfoCreateProcess m_create_process_info;
os::Event m_event;
public:
GdbServerImpl(int socket);
GdbServerImpl(int socket, void *thread_stack, size_t stack_size);
~GdbServerImpl();
void LoopProcess();
@ -40,9 +69,25 @@ namespace ams::dmnt {
char *ReceivePacket(bool *out_break, char *dst, size_t size) { return m_packet_io.ReceivePacket(out_break, dst, size, std::addressof(m_session)); }
private:
bool HasDebugProcess() const { return m_debug_handle != svc::InvalidHandle; }
bool Is64Bit() const { return true; /* TODO: Retrieve from debug process info. */ }
bool Is64Bit() const { return (m_create_process_info.flags & svc::CreateProcessFlag_Is64Bit) == svc::CreateProcessFlag_Is64Bit; }
bool Is64BitAddressSpace() const { return (m_create_process_info.flags & svc::CreateProcessFlag_AddressSpaceMask) == svc::CreateProcessFlag_AddressSpace64Bit; }
private:
static void DebugEventsThreadEntry(void *arg) { static_cast<GdbServerImpl *>(arg)->DebugEventsThread(); }
void DebugEventsThread();
void ProcessDebugEvents();
void SetStopReplyPacket(GdbSignal signal);
private:
void H();
void Hg();
bool g();
void m();
void v();
void vAttach();
void q();
void qAttached();
@ -51,6 +96,7 @@ namespace ams::dmnt {
void qXfer();
void qXferFeaturesRead();
void qXferOsdataRead();
bool qXferThreadsRead();
void QuestionMark();
};