Cemu/src/Cafe/HW/Espresso/Debugger/GDBBreakpoints.cpp
GaryOderNichts 4405116324
GDBStub: Support watchpoints on linux (#1030)
* GDBStub: Support watchpoints on linux
* GDBStub: Use `TCP_NODELAY`
2023-12-23 15:25:01 -08:00

305 lines
8.2 KiB
C++

#include "GDBBreakpoints.h"
#include "Debugger.h"
#include "Cafe/HW/Espresso/Recompiler/PPCRecompiler.h"
#if defined(ARCH_X86_64) && BOOST_OS_LINUX
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/user.h>
DRType _GetDR(pid_t tid, int drIndex)
{
size_t drOffset = offsetof(struct user, u_debugreg) + drIndex * sizeof(user::u_debugreg[0]);
long v;
v = ptrace(PTRACE_PEEKUSER, tid, drOffset, nullptr);
if (v == -1)
perror("ptrace(PTRACE_PEEKUSER)");
return (DRType)v;
}
void _SetDR(pid_t tid, int drIndex, DRType newValue)
{
size_t drOffset = offsetof(struct user, u_debugreg) + drIndex * sizeof(user::u_debugreg[0]);
long rc = ptrace(PTRACE_POKEUSER, tid, drOffset, newValue);
if (rc == -1)
perror("ptrace(PTRACE_POKEUSER)");
}
DRType _ReadDR6()
{
pid_t tid = gettid();
// linux doesn't let us attach to the current thread / threads in the current thread group
// we have to create a child process which then modifies the debug registers and quits
pid_t child = fork();
if (child == -1)
{
perror("fork");
return 0;
}
if (child == 0)
{
if (ptrace(PTRACE_ATTACH, tid, nullptr, nullptr))
{
perror("attach");
_exit(0);
}
waitpid(tid, NULL, 0);
uint64_t dr6 = _GetDR(tid, 6);
if (ptrace(PTRACE_DETACH, tid, nullptr, nullptr))
perror("detach");
// since the status code only uses the lower 8 bits, we have to discard the rest of DR6
// this should be fine though, since the lower 4 bits of DR6 contain all the bp conditions
_exit(dr6 & 0xff);
}
// wait for child process
int wstatus;
waitpid(child, &wstatus, 0);
return (DRType)WEXITSTATUS(wstatus);
}
#endif
GDBServer::ExecutionBreakpoint::ExecutionBreakpoint(MPTR address, BreakpointType type, bool visible, std::string reason)
: m_address(address), m_removedAfterInterrupt(false), m_reason(std::move(reason))
{
if (type == BreakpointType::BP_SINGLE)
{
this->m_pauseThreads = true;
this->m_restoreAfterInterrupt = false;
this->m_deleteAfterAnyInterrupt = false;
this->m_pauseOnNextInterrupt = false;
this->m_visible = visible;
}
else if (type == BreakpointType::BP_PERSISTENT)
{
this->m_pauseThreads = true;
this->m_restoreAfterInterrupt = true;
this->m_deleteAfterAnyInterrupt = false;
this->m_pauseOnNextInterrupt = false;
this->m_visible = visible;
}
else if (type == BreakpointType::BP_RESTORE_POINT)
{
this->m_pauseThreads = false;
this->m_restoreAfterInterrupt = false;
this->m_deleteAfterAnyInterrupt = false;
this->m_pauseOnNextInterrupt = false;
this->m_visible = false;
}
else if (type == BreakpointType::BP_STEP_POINT)
{
this->m_pauseThreads = false;
this->m_restoreAfterInterrupt = false;
this->m_deleteAfterAnyInterrupt = true;
this->m_pauseOnNextInterrupt = true;
this->m_visible = false;
}
this->m_origOpCode = memory_readU32(address);
memory_writeU32(address, DEBUGGER_BP_T_GDBSTUB_TW);
PPCRecompiler_invalidateRange(address, address + 4);
}
GDBServer::ExecutionBreakpoint::~ExecutionBreakpoint()
{
memory_writeU32(this->m_address, this->m_origOpCode);
PPCRecompiler_invalidateRange(this->m_address, this->m_address + 4);
}
uint32 GDBServer::ExecutionBreakpoint::GetVisibleOpCode() const
{
if (this->m_visible)
return memory_readU32(this->m_address);
else
return this->m_origOpCode;
}
void GDBServer::ExecutionBreakpoint::RemoveTemporarily()
{
memory_writeU32(this->m_address, this->m_origOpCode);
PPCRecompiler_invalidateRange(this->m_address, this->m_address + 4);
this->m_restoreAfterInterrupt = true;
}
void GDBServer::ExecutionBreakpoint::Restore()
{
memory_writeU32(this->m_address, DEBUGGER_BP_T_GDBSTUB_TW);
PPCRecompiler_invalidateRange(this->m_address, this->m_address + 4);
this->m_restoreAfterInterrupt = false;
}
namespace coreinit
{
#if BOOST_OS_LINUX
std::vector<pid_t>& OSGetSchedulerThreadIds();
#endif
std::vector<std::thread::native_handle_type>& OSGetSchedulerThreads();
}
GDBServer::AccessBreakpoint::AccessBreakpoint(MPTR address, AccessPointType type)
: m_address(address), m_type(type)
{
#if defined(ARCH_X86_64) && BOOST_OS_WINDOWS
for (auto& hThreadNH : coreinit::OSGetSchedulerThreads())
{
HANDLE hThread = (HANDLE)hThreadNH;
CONTEXT ctx{};
ctx.ContextFlags = CONTEXT_DEBUG_REGISTERS;
SuspendThread(hThread);
GetThreadContext(hThread, &ctx);
// use BP 2/3 for gdb stub since cemu's internal debugger uses BP 0/1 already
ctx.Dr2 = (DWORD64)memory_getPointerFromVirtualOffset(address);
ctx.Dr3 = (DWORD64)memory_getPointerFromVirtualOffset(address);
// breakpoint 2
SetBits(ctx.Dr7, 4, 1, 1); // breakpoint #3 enabled: true
SetBits(ctx.Dr7, 24, 2, 1); // breakpoint #3 condition: 1 (write)
SetBits(ctx.Dr7, 26, 2, 3); // breakpoint #3 length: 3 (4 bytes)
// breakpoint 3
SetBits(ctx.Dr7, 6, 1, 1); // breakpoint #4 enabled: true
SetBits(ctx.Dr7, 28, 2, 3); // breakpoint #4 condition: 3 (read & write)
SetBits(ctx.Dr7, 30, 2, 3); // breakpoint #4 length: 3 (4 bytes)
SetThreadContext(hThread, &ctx);
ResumeThread(hThread);
}
#elif defined(ARCH_X86_64) && BOOST_OS_LINUX
// linux doesn't let us attach to threads which are in the same thread group as our current thread
// we have to create a child process which then modifies the debug registers and quits
pid_t child = fork();
if (child == -1)
{
perror("fork");
return;
}
if (child == 0)
{
for (pid_t tid : coreinit::OSGetSchedulerThreadIds())
{
long rc = ptrace(PTRACE_ATTACH, tid, nullptr, nullptr);
if (rc == -1)
perror("ptrace(PTRACE_ATTACH)");
waitpid(tid, nullptr, 0);
DRType dr7 = _GetDR(tid, 7);
// use BP 2/3 for gdb stub since cemu's internal debugger uses BP 0/1 already
DRType dr2 = (uint64)memory_getPointerFromVirtualOffset(address);
DRType dr3 = (uint64)memory_getPointerFromVirtualOffset(address);
// breakpoint 2
SetBits(dr7, 4, 1, 1); // breakpoint #3 enabled: true
SetBits(dr7, 24, 2, 1); // breakpoint #3 condition: 1 (write)
SetBits(dr7, 26, 2, 3); // breakpoint #3 length: 3 (4 bytes)
// breakpoint 3
SetBits(dr7, 6, 1, 1); // breakpoint #4 enabled: true
SetBits(dr7, 28, 2, 3); // breakpoint #4 condition: 3 (read & write)
SetBits(dr7, 30, 2, 3); // breakpoint #4 length: 3 (4 bytes)
_SetDR(tid, 2, dr2);
_SetDR(tid, 3, dr3);
_SetDR(tid, 7, dr7);
rc = ptrace(PTRACE_DETACH, tid, nullptr, nullptr);
if (rc == -1)
perror("ptrace(PTRACE_DETACH)");
}
// exit child process
_exit(0);
}
// wait for child process
waitpid(child, nullptr, 0);
#else
cemuLog_log(LogType::Force, "Debugger read/write breakpoints are not supported on non-x86 CPUs yet.");
#endif
}
GDBServer::AccessBreakpoint::~AccessBreakpoint()
{
#if defined(ARCH_X86_64) && BOOST_OS_WINDOWS
for (auto& hThreadNH : coreinit::OSGetSchedulerThreads())
{
HANDLE hThread = (HANDLE)hThreadNH;
CONTEXT ctx{};
ctx.ContextFlags = CONTEXT_DEBUG_REGISTERS;
SuspendThread(hThread);
GetThreadContext(hThread, &ctx);
// reset BP 2/3 to zero
ctx.Dr2 = (DWORD64)0;
ctx.Dr3 = (DWORD64)0;
// breakpoint 2
SetBits(ctx.Dr7, 4, 1, 0);
SetBits(ctx.Dr7, 24, 2, 0);
SetBits(ctx.Dr7, 26, 2, 0);
// breakpoint 3
SetBits(ctx.Dr7, 6, 1, 0);
SetBits(ctx.Dr7, 28, 2, 0);
SetBits(ctx.Dr7, 30, 2, 0);
SetThreadContext(hThread, &ctx);
ResumeThread(hThread);
}
#elif defined(ARCH_X86_64) && BOOST_OS_LINUX
// linux doesn't let us attach to threads which are in the same thread group as our current thread
// we have to create a child process which then modifies the debug registers and quits
pid_t child = fork();
if (child == -1)
{
perror("fork");
return;
}
if (child == 0)
{
for (pid_t tid : coreinit::OSGetSchedulerThreadIds())
{
long rc = ptrace(PTRACE_ATTACH, tid, nullptr, nullptr);
if (rc == -1)
perror("ptrace(PTRACE_ATTACH)");
waitpid(tid, nullptr, 0);
DRType dr7 = _GetDR(tid, 7);
// reset BP 2/3 to zero
DRType dr2 = 0;
DRType dr3 = 0;
// breakpoint 2
SetBits(dr7, 4, 1, 0);
SetBits(dr7, 24, 2, 0);
SetBits(dr7, 26, 2, 0);
// breakpoint 3
SetBits(dr7, 6, 1, 0);
SetBits(dr7, 28, 2, 0);
SetBits(dr7, 30, 2, 0);
_SetDR(tid, 2, dr2);
_SetDR(tid, 3, dr3);
_SetDR(tid, 7, dr7);
rc = ptrace(PTRACE_DETACH, tid, nullptr, nullptr);
if (rc == -1)
perror("ptrace(PTRACE_DETACH)");
}
// exit child process
_exit(0);
}
// wait for child process
waitpid(child, nullptr, 0);
#endif
}