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llvm-project/lldb/source/Plugins/Process/Linux/ProcessMonitor.cpp

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//===-- ProcessMonitor.cpp ------------------------------------ -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// C Includes
#include <errno.h>
#include <poll.h>
#include <string.h>
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
// C++ Includes
// Other libraries and framework includes
#include "lldb/Core/Error.h"
#include "lldb/Core/RegisterValue.h"
#include "lldb/Core/Scalar.h"
#include "lldb/Host/Host.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Utility/PseudoTerminal.h"
#include "LinuxThread.h"
#include "ProcessLinux.h"
#include "ProcessMonitor.h"
using namespace lldb_private;
//------------------------------------------------------------------------------
// Static implementations of ProcessMonitor::ReadMemory and
// ProcessMonitor::WriteMemory. This enables mutual recursion between these
// functions without needed to go thru the thread funnel.
static size_t
DoReadMemory(lldb::pid_t pid, unsigned word_size,
lldb::addr_t vm_addr, void *buf, size_t size, Error &error)
{
unsigned char *dst = static_cast<unsigned char*>(buf);
size_t bytes_read;
size_t remainder;
long data;
for (bytes_read = 0; bytes_read < size; bytes_read += remainder)
{
errno = 0;
data = ptrace(PTRACE_PEEKDATA, pid, vm_addr, NULL);
if (data == -1L && errno)
{
error.SetErrorToErrno();
return bytes_read;
}
remainder = size - bytes_read;
remainder = remainder > word_size ? word_size : remainder;
for (unsigned i = 0; i < remainder; ++i)
dst[i] = ((data >> i*8) & 0xFF);
vm_addr += word_size;
dst += word_size;
}
return bytes_read;
}
static size_t
DoWriteMemory(lldb::pid_t pid, unsigned word_size,
lldb::addr_t vm_addr, const void *buf, size_t size, Error &error)
{
const unsigned char *src = static_cast<const unsigned char*>(buf);
size_t bytes_written = 0;
size_t remainder;
for (bytes_written = 0; bytes_written < size; bytes_written += remainder)
{
remainder = size - bytes_written;
remainder = remainder > word_size ? word_size : remainder;
if (remainder == word_size)
{
unsigned long data = 0;
for (unsigned i = 0; i < word_size; ++i)
data |= (unsigned long)src[i] << i*8;
if (ptrace(PTRACE_POKEDATA, pid, vm_addr, data))
{
error.SetErrorToErrno();
return bytes_written;
}
}
else
{
unsigned char buff[8];
if (DoReadMemory(pid, word_size, vm_addr,
buff, word_size, error) != word_size)
return bytes_written;
memcpy(buff, src, remainder);
if (DoWriteMemory(pid, word_size, vm_addr,
buff, word_size, error) != word_size)
return bytes_written;
}
vm_addr += word_size;
src += word_size;
}
return bytes_written;
}
// Simple helper function to ensure flags are enabled on the given file
// descriptor.
static bool
EnsureFDFlags(int fd, int flags, Error &error)
{
int status;
if ((status = fcntl(fd, F_GETFL)) == -1)
{
error.SetErrorToErrno();
return false;
}
if (fcntl(fd, F_SETFL, status | flags) == -1)
{
error.SetErrorToErrno();
return false;
}
return true;
}
//------------------------------------------------------------------------------
/// @class Operation
/// @brief Represents a ProcessMonitor operation.
///
/// Under Linux, it is not possible to ptrace() from any other thread but the
/// one that spawned or attached to the process from the start. Therefore, when
/// a ProcessMonitor is asked to deliver or change the state of an inferior
/// process the operation must be "funneled" to a specific thread to perform the
/// task. The Operation class provides an abstract base for all services the
/// ProcessMonitor must perform via the single virtual function Execute, thus
/// encapsulating the code that needs to run in the privileged context.
class Operation
{
public:
virtual void Execute(ProcessMonitor *monitor) = 0;
};
//------------------------------------------------------------------------------
/// @class ReadOperation
/// @brief Implements ProcessMonitor::ReadMemory.
class ReadOperation : public Operation
{
public:
ReadOperation(lldb::addr_t addr, void *buff, size_t size,
Error &error, size_t &result)
: m_addr(addr), m_buff(buff), m_size(size),
m_error(error), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::addr_t m_addr;
void *m_buff;
size_t m_size;
Error &m_error;
size_t &m_result;
};
void
ReadOperation::Execute(ProcessMonitor *monitor)
{
const unsigned word_size = monitor->GetProcess().GetAddressByteSize();
lldb::pid_t pid = monitor->GetPID();
m_result = DoReadMemory(pid, word_size, m_addr, m_buff, m_size, m_error);
}
//------------------------------------------------------------------------------
/// @class ReadOperation
/// @brief Implements ProcessMonitor::WriteMemory.
class WriteOperation : public Operation
{
public:
WriteOperation(lldb::addr_t addr, const void *buff, size_t size,
Error &error, size_t &result)
: m_addr(addr), m_buff(buff), m_size(size),
m_error(error), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::addr_t m_addr;
const void *m_buff;
size_t m_size;
Error &m_error;
size_t &m_result;
};
void
WriteOperation::Execute(ProcessMonitor *monitor)
{
const unsigned word_size = monitor->GetProcess().GetAddressByteSize();
lldb::pid_t pid = monitor->GetPID();
m_result = DoWriteMemory(pid, word_size, m_addr, m_buff, m_size, m_error);
}
//------------------------------------------------------------------------------
/// @class ReadRegOperation
/// @brief Implements ProcessMonitor::ReadRegisterValue.
class ReadRegOperation : public Operation
{
public:
ReadRegOperation(unsigned offset, RegisterValue &value, bool &result)
: m_offset(offset), m_value(value), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
unsigned m_offset;
RegisterValue &m_value;
bool &m_result;
};
void
ReadRegOperation::Execute(ProcessMonitor *monitor)
{
lldb::pid_t pid = monitor->GetPID();
// Set errno to zero so that we can detect a failed peek.
errno = 0;
unsigned long data = ptrace(PTRACE_PEEKUSER, pid, m_offset, NULL);
if (data == -1UL && errno)
m_result = false;
else
{
m_value = data;
m_result = true;
}
}
//------------------------------------------------------------------------------
/// @class WriteRegOperation
/// @brief Implements ProcessMonitor::WriteRegisterValue.
class WriteRegOperation : public Operation
{
public:
WriteRegOperation(unsigned offset, const RegisterValue &value, bool &result)
: m_offset(offset), m_value(value), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
unsigned m_offset;
const RegisterValue &m_value;
bool &m_result;
};
void
WriteRegOperation::Execute(ProcessMonitor *monitor)
{
lldb::pid_t pid = monitor->GetPID();
if (ptrace(PTRACE_POKEUSER, pid, m_offset, m_value.GetAsUInt64()))
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class ReadGPROperation
/// @brief Implements ProcessMonitor::ReadGPR.
class ReadGPROperation : public Operation
{
public:
ReadGPROperation(void *buf, bool &result)
: m_buf(buf), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
void *m_buf;
bool &m_result;
};
void
ReadGPROperation::Execute(ProcessMonitor *monitor)
{
if (ptrace(PTRACE_GETREGS, monitor->GetPID(), NULL, m_buf) < 0)
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class ReadFPROperation
/// @brief Implements ProcessMonitor::ReadFPR.
class ReadFPROperation : public Operation
{
public:
ReadFPROperation(void *buf, bool &result)
: m_buf(buf), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
void *m_buf;
bool &m_result;
};
void
ReadFPROperation::Execute(ProcessMonitor *monitor)
{
if (ptrace(PTRACE_GETFPREGS, monitor->GetPID(), NULL, m_buf) < 0)
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class ResumeOperation
/// @brief Implements ProcessMonitor::Resume.
class ResumeOperation : public Operation
{
public:
ResumeOperation(lldb::tid_t tid, uint32_t signo, bool &result) :
m_tid(tid), m_signo(signo), m_result(result) { }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
uint32_t m_signo;
bool &m_result;
};
void
ResumeOperation::Execute(ProcessMonitor *monitor)
{
int data = 0;
if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
data = m_signo;
if (ptrace(PTRACE_CONT, m_tid, NULL, data))
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class ResumeOperation
/// @brief Implements ProcessMonitor::SingleStep.
class SingleStepOperation : public Operation
{
public:
SingleStepOperation(lldb::tid_t tid, uint32_t signo, bool &result)
: m_tid(tid), m_signo(signo), m_result(result) { }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
uint32_t m_signo;
bool &m_result;
};
void
SingleStepOperation::Execute(ProcessMonitor *monitor)
{
int data = 0;
if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
data = m_signo;
if (ptrace(PTRACE_SINGLESTEP, m_tid, NULL, data))
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class SiginfoOperation
/// @brief Implements ProcessMonitor::GetSignalInfo.
class SiginfoOperation : public Operation
{
public:
SiginfoOperation(lldb::tid_t tid, void *info, bool &result)
: m_tid(tid), m_info(info), m_result(result) { }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
void *m_info;
bool &m_result;
};
void
SiginfoOperation::Execute(ProcessMonitor *monitor)
{
if (ptrace(PTRACE_GETSIGINFO, m_tid, NULL, m_info))
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class EventMessageOperation
/// @brief Implements ProcessMonitor::GetEventMessage.
class EventMessageOperation : public Operation
{
public:
EventMessageOperation(lldb::tid_t tid, unsigned long *message, bool &result)
: m_tid(tid), m_message(message), m_result(result) { }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
unsigned long *m_message;
bool &m_result;
};
void
EventMessageOperation::Execute(ProcessMonitor *monitor)
{
if (ptrace(PTRACE_GETEVENTMSG, m_tid, NULL, m_message))
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class KillOperation
/// @brief Implements ProcessMonitor::BringProcessIntoLimbo.
class KillOperation : public Operation
{
public:
KillOperation(bool &result) : m_result(result) { }
void Execute(ProcessMonitor *monitor);
private:
bool &m_result;
};
void
KillOperation::Execute(ProcessMonitor *monitor)
{
lldb::pid_t pid = monitor->GetPID();
if (ptrace(PTRACE_KILL, pid, NULL, NULL))
m_result = false;
else
m_result = true;
}
ProcessMonitor::LaunchArgs::LaunchArgs(ProcessMonitor *monitor,
lldb_private::Module *module,
char const **argv,
char const **envp,
const char *stdin_path,
const char *stdout_path,
const char *stderr_path)
: m_monitor(monitor),
m_module(module),
m_argv(argv),
m_envp(envp),
m_stdin_path(stdin_path),
m_stdout_path(stdout_path),
m_stderr_path(stderr_path)
{
sem_init(&m_semaphore, 0, 0);
}
ProcessMonitor::LaunchArgs::~LaunchArgs()
{
sem_destroy(&m_semaphore);
}
//------------------------------------------------------------------------------
/// The basic design of the ProcessMonitor is built around two threads.
///
/// One thread (@see SignalThread) simply blocks on a call to waitpid() looking
/// for changes in the debugee state. When a change is detected a
/// ProcessMessage is sent to the associated ProcessLinux instance. This thread
/// "drives" state changes in the debugger.
///
/// The second thread (@see OperationThread) is responsible for two things 1)
/// launching or attaching to the inferior process, and then 2) servicing
/// operations such as register reads/writes, stepping, etc. See the comments
/// on the Operation class for more info as to why this is needed.
ProcessMonitor::ProcessMonitor(ProcessLinux *process,
Module *module,
const char *argv[],
const char *envp[],
const char *stdin_path,
const char *stdout_path,
const char *stderr_path,
lldb_private::Error &error)
: m_process(process),
m_operation_thread(LLDB_INVALID_HOST_THREAD),
m_pid(LLDB_INVALID_PROCESS_ID),
m_terminal_fd(-1),
m_monitor_thread(LLDB_INVALID_HOST_THREAD),
m_client_fd(-1),
m_server_fd(-1)
{
std::auto_ptr<LaunchArgs> args;
args.reset(new LaunchArgs(this, module, argv, envp,
stdin_path, stdout_path, stderr_path));
// Server/client descriptors.
if (!EnableIPC())
{
error.SetErrorToGenericError();
error.SetErrorString("Monitor failed to initialize.");
}
StartOperationThread(args.get(), error);
if (!error.Success())
return;
WAIT_AGAIN:
// Wait for the operation thread to initialize.
if (sem_wait(&args->m_semaphore))
{
if (errno == EINTR)
goto WAIT_AGAIN;
else
{
error.SetErrorToErrno();
return;
}
}
// Check that the launch was a success.
if (!args->m_error.Success())
{
StopOperationThread();
error = args->m_error;
return;
}
// Finally, start monitoring the child process for change in state.
m_monitor_thread = Host::StartMonitoringChildProcess(
ProcessMonitor::MonitorCallback, this, GetPID(), true);
if (!IS_VALID_LLDB_HOST_THREAD(m_monitor_thread))
{
error.SetErrorToGenericError();
error.SetErrorString("Process launch failed.");
return;
}
}
ProcessMonitor::~ProcessMonitor()
{
StopMonitor();
}
//------------------------------------------------------------------------------
// Thread setup and tear down.
void
ProcessMonitor::StartOperationThread(LaunchArgs *args, Error &error)
{
static const char *g_thread_name = "lldb.process.linux.operation";
if (IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
return;
m_operation_thread =
Host::ThreadCreate(g_thread_name, OperationThread, args, &error);
}
void
ProcessMonitor::StopOperationThread()
{
lldb::thread_result_t result;
if (!IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
return;
Host::ThreadCancel(m_operation_thread, NULL);
Host::ThreadJoin(m_operation_thread, &result, NULL);
}
void *
ProcessMonitor::OperationThread(void *arg)
{
LaunchArgs *args = static_cast<LaunchArgs*>(arg);
if (!Launch(args))
return NULL;
ServeOperation(args);
return NULL;
}
bool
ProcessMonitor::Launch(LaunchArgs *args)
{
ProcessMonitor *monitor = args->m_monitor;
ProcessLinux &process = monitor->GetProcess();
const char **argv = args->m_argv;
const char **envp = args->m_envp;
const char *stdin_path = args->m_stdin_path;
const char *stdout_path = args->m_stdout_path;
const char *stderr_path = args->m_stderr_path;
lldb_utility::PseudoTerminal terminal;
const size_t err_len = 1024;
char err_str[err_len];
lldb::pid_t pid;
lldb::ThreadSP inferior;
// Propagate the environment if one is not supplied.
if (envp == NULL || envp[0] == NULL)
envp = const_cast<const char **>(environ);
// Pseudo terminal setup.
if (!terminal.OpenFirstAvailableMaster(O_RDWR | O_NOCTTY, err_str, err_len))
{
args->m_error.SetErrorToGenericError();
args->m_error.SetErrorString("Could not open controlling TTY.");
goto FINISH;
}
if ((pid = terminal.Fork(err_str, err_len)) < 0)
{
args->m_error.SetErrorToGenericError();
args->m_error.SetErrorString("Process fork failed.");
goto FINISH;
}
// Child process.
if (pid == 0)
{
// Trace this process.
ptrace(PTRACE_TRACEME, 0, NULL, NULL);
// Do not inherit setgid powers.
setgid(getgid());
// Let us have our own process group.
setpgid(0, 0);
// Dup file descriptors if needed.
//
// FIXME: If two or more of the paths are the same we needlessly open
// the same file multiple times.
if (stdin_path != NULL && stdin_path[0])
if (!DupDescriptor(stdin_path, STDIN_FILENO, O_RDONLY | O_CREAT))
exit(1);
if (stdout_path != NULL && stdout_path[0])
if (!DupDescriptor(stdout_path, STDOUT_FILENO, O_WRONLY | O_CREAT))
exit(1);
if (stderr_path != NULL && stderr_path[0])
if (!DupDescriptor(stderr_path, STDOUT_FILENO, O_WRONLY | O_CREAT))
exit(1);
// Execute. We should never return.
execve(argv[0],
const_cast<char *const *>(argv),
const_cast<char *const *>(envp));
exit(-1);
}
// Wait for the child process to to trap on its call to execve.
int status;
if ((status = waitpid(pid, NULL, 0)) < 0)
{
// execve likely failed for some reason.
args->m_error.SetErrorToErrno();
goto FINISH;
}
assert(status == pid && "Could not sync with inferior process.");
// Have the child raise an event on exit. This is used to keep the child in
// limbo until it is destroyed.
if (ptrace(PTRACE_SETOPTIONS, pid, NULL, PTRACE_O_TRACEEXIT) < 0)
{
args->m_error.SetErrorToErrno();
goto FINISH;
}
// Release the master terminal descriptor and pass it off to the
// ProcessMonitor instance. Similarly stash the inferior pid.
monitor->m_terminal_fd = terminal.ReleaseMasterFileDescriptor();
monitor->m_pid = pid;
// Set the terminal fd to be in non blocking mode (it simplifies the
// implementation of ProcessLinux::GetSTDOUT to have a non-blocking
// descriptor to read from).
if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
goto FINISH;
// Update the process thread list with this new thread and mark it as
// current.
inferior.reset(new LinuxThread(process, pid));
process.GetThreadList().AddThread(inferior);
process.GetThreadList().SetSelectedThreadByID(pid);
// Let our process instance know the thread has stopped.
process.SendMessage(ProcessMessage::Trace(pid));
FINISH:
return args->m_error.Success();
}
bool
ProcessMonitor::EnableIPC()
{
int fd[2];
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fd))
return false;
m_client_fd = fd[0];
m_server_fd = fd[1];
return true;
}
bool
ProcessMonitor::MonitorCallback(void *callback_baton,
lldb::pid_t pid,
int signal,
int status)
{
ProcessMessage message;
ProcessMonitor *monitor = static_cast<ProcessMonitor*>(callback_baton);
ProcessLinux *process = monitor->m_process;
bool stop_monitoring;
siginfo_t info;
if (!monitor->GetSignalInfo(pid, &info))
stop_monitoring = true; // pid is gone. Bail.
else {
switch (info.si_signo)
{
case SIGTRAP:
message = MonitorSIGTRAP(monitor, &info, pid);
break;
default:
message = MonitorSignal(monitor, &info, pid);
break;
}
process->SendMessage(message);
stop_monitoring = message.GetKind() == ProcessMessage::eExitMessage;
}
return stop_monitoring;
}
ProcessMessage
ProcessMonitor::MonitorSIGTRAP(ProcessMonitor *monitor,
const struct siginfo *info, lldb::pid_t pid)
{
ProcessMessage message;
assert(info->si_signo == SIGTRAP && "Unexpected child signal!");
switch (info->si_code)
{
default:
assert(false && "Unexpected SIGTRAP code!");
break;
case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)):
{
// The inferior process is about to exit. Maintain the process in a
// state of "limbo" until we are explicitly commanded to detach,
// destroy, resume, etc.
unsigned long data = 0;
if (!monitor->GetEventMessage(pid, &data))
data = -1;
message = ProcessMessage::Limbo(pid, (data >> 8));
break;
}
case 0:
case TRAP_TRACE:
message = ProcessMessage::Trace(pid);
break;
case SI_KERNEL:
case TRAP_BRKPT:
message = ProcessMessage::Break(pid);
break;
}
return message;
}
ProcessMessage
ProcessMonitor::MonitorSignal(ProcessMonitor *monitor,
const struct siginfo *info, lldb::pid_t pid)
{
ProcessMessage message;
int signo = info->si_signo;
// POSIX says that process behaviour is undefined after it ignores a SIGFPE,
// SIGILL, SIGSEGV, or SIGBUS *unless* that signal was generated by a
// kill(2) or raise(3). Similarly for tgkill(2) on Linux.
//
// IOW, user generated signals never generate what we consider to be a
// "crash".
//
// Similarly, ACK signals generated by this monitor.
if (info->si_code == SI_TKILL || info->si_code == SI_USER)
{
if (info->si_pid == getpid())
return ProcessMessage::SignalDelivered(pid, signo);
else
return ProcessMessage::Signal(pid, signo);
}
if (signo == SIGSEGV) {
lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
ProcessMessage::CrashReason reason = GetCrashReasonForSIGSEGV(info);
return ProcessMessage::Crash(pid, reason, signo, fault_addr);
}
if (signo == SIGILL) {
lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
ProcessMessage::CrashReason reason = GetCrashReasonForSIGILL(info);
return ProcessMessage::Crash(pid, reason, signo, fault_addr);
}
if (signo == SIGFPE) {
lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
ProcessMessage::CrashReason reason = GetCrashReasonForSIGFPE(info);
return ProcessMessage::Crash(pid, reason, signo, fault_addr);
}
if (signo == SIGBUS) {
lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
ProcessMessage::CrashReason reason = GetCrashReasonForSIGBUS(info);
return ProcessMessage::Crash(pid, reason, signo, fault_addr);
}
// Everything else is "normal" and does not require any special action on
// our part.
return ProcessMessage::Signal(pid, signo);
}
ProcessMessage::CrashReason
ProcessMonitor::GetCrashReasonForSIGSEGV(const struct siginfo *info)
{
ProcessMessage::CrashReason reason;
assert(info->si_signo == SIGSEGV);
reason = ProcessMessage::eInvalidCrashReason;
switch (info->si_code)
{
default:
assert(false && "unexpected si_code for SIGSEGV");
break;
case SEGV_MAPERR:
reason = ProcessMessage::eInvalidAddress;
break;
case SEGV_ACCERR:
reason = ProcessMessage::ePrivilegedAddress;
break;
}
return reason;
}
ProcessMessage::CrashReason
ProcessMonitor::GetCrashReasonForSIGILL(const struct siginfo *info)
{
ProcessMessage::CrashReason reason;
assert(info->si_signo == SIGILL);
reason = ProcessMessage::eInvalidCrashReason;
switch (info->si_code)
{
default:
assert(false && "unexpected si_code for SIGILL");
break;
case ILL_ILLOPC:
reason = ProcessMessage::eIllegalOpcode;
break;
case ILL_ILLOPN:
reason = ProcessMessage::eIllegalOperand;
break;
case ILL_ILLADR:
reason = ProcessMessage::eIllegalAddressingMode;
break;
case ILL_ILLTRP:
reason = ProcessMessage::eIllegalTrap;
break;
case ILL_PRVOPC:
reason = ProcessMessage::ePrivilegedOpcode;
break;
case ILL_PRVREG:
reason = ProcessMessage::ePrivilegedRegister;
break;
case ILL_COPROC:
reason = ProcessMessage::eCoprocessorError;
break;
case ILL_BADSTK:
reason = ProcessMessage::eInternalStackError;
break;
}
return reason;
}
ProcessMessage::CrashReason
ProcessMonitor::GetCrashReasonForSIGFPE(const struct siginfo *info)
{
ProcessMessage::CrashReason reason;
assert(info->si_signo == SIGFPE);
reason = ProcessMessage::eInvalidCrashReason;
switch (info->si_code)
{
default:
assert(false && "unexpected si_code for SIGFPE");
break;
case FPE_INTDIV:
reason = ProcessMessage::eIntegerDivideByZero;
break;
case FPE_INTOVF:
reason = ProcessMessage::eIntegerOverflow;
break;
case FPE_FLTDIV:
reason = ProcessMessage::eFloatDivideByZero;
break;
case FPE_FLTOVF:
reason = ProcessMessage::eFloatOverflow;
break;
case FPE_FLTUND:
reason = ProcessMessage::eFloatUnderflow;
break;
case FPE_FLTRES:
reason = ProcessMessage::eFloatInexactResult;
break;
case FPE_FLTINV:
reason = ProcessMessage::eFloatInvalidOperation;
break;
case FPE_FLTSUB:
reason = ProcessMessage::eFloatSubscriptRange;
break;
}
return reason;
}
ProcessMessage::CrashReason
ProcessMonitor::GetCrashReasonForSIGBUS(const struct siginfo *info)
{
ProcessMessage::CrashReason reason;
assert(info->si_signo == SIGBUS);
reason = ProcessMessage::eInvalidCrashReason;
switch (info->si_code)
{
default:
assert(false && "unexpected si_code for SIGBUS");
break;
case BUS_ADRALN:
reason = ProcessMessage::eIllegalAlignment;
break;
case BUS_ADRERR:
reason = ProcessMessage::eIllegalAddress;
break;
case BUS_OBJERR:
reason = ProcessMessage::eHardwareError;
break;
}
return reason;
}
void
ProcessMonitor::ServeOperation(LaunchArgs *args)
{
int status;
pollfd fdset;
ProcessMonitor *monitor = args->m_monitor;
fdset.fd = monitor->m_server_fd;
fdset.events = POLLIN | POLLPRI;
fdset.revents = 0;
// We are finised with the arguments and are ready to go. Sync with the
// parent thread and start serving operations on the inferior.
sem_post(&args->m_semaphore);
for (;;)
{
if ((status = poll(&fdset, 1, -1)) < 0)
{
switch (errno)
{
default:
assert(false && "Unexpected poll() failure!");
continue;
case EINTR: continue; // Just poll again.
case EBADF: return; // Connection terminated.
}
}
assert(status == 1 && "Too many descriptors!");
if (fdset.revents & POLLIN)
{
Operation *op = NULL;
READ_AGAIN:
if ((status = read(fdset.fd, &op, sizeof(op))) < 0)
{
// There is only one acceptable failure.
assert(errno == EINTR);
goto READ_AGAIN;
}
assert(status == sizeof(op));
op->Execute(monitor);
write(fdset.fd, &op, sizeof(op));
}
}
}
void
ProcessMonitor::DoOperation(Operation *op)
{
int status;
Operation *ack = NULL;
Mutex::Locker lock(m_server_mutex);
// FIXME: Do proper error checking here.
write(m_client_fd, &op, sizeof(op));
READ_AGAIN:
if ((status = read(m_client_fd, &ack, sizeof(ack))) < 0)
{
// If interrupted by a signal handler try again. Otherwise the monitor
// thread probably died and we have a stale file descriptor -- abort the
// operation.
if (errno == EINTR)
goto READ_AGAIN;
return;
}
assert(status == sizeof(ack));
assert(ack == op && "Invalid monitor thread response!");
}
size_t
ProcessMonitor::ReadMemory(lldb::addr_t vm_addr, void *buf, size_t size,
Error &error)
{
size_t result;
ReadOperation op(vm_addr, buf, size, error, result);
DoOperation(&op);
return result;
}
size_t
ProcessMonitor::WriteMemory(lldb::addr_t vm_addr, const void *buf, size_t size,
lldb_private::Error &error)
{
size_t result;
WriteOperation op(vm_addr, buf, size, error, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::ReadRegisterValue(unsigned offset, RegisterValue &value)
{
bool result;
ReadRegOperation op(offset, value, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::WriteRegisterValue(unsigned offset, const RegisterValue &value)
{
bool result;
WriteRegOperation op(offset, value, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::ReadGPR(void *buf)
{
bool result;
ReadGPROperation op(buf, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::ReadFPR(void *buf)
{
bool result;
ReadFPROperation op(buf, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::Resume(lldb::tid_t tid, uint32_t signo)
{
bool result;
ResumeOperation op(tid, signo, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::SingleStep(lldb::tid_t tid, uint32_t signo)
{
bool result;
SingleStepOperation op(tid, signo, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::BringProcessIntoLimbo()
{
bool result;
KillOperation op(result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::GetSignalInfo(lldb::tid_t tid, void *siginfo)
{
bool result;
SiginfoOperation op(tid, siginfo, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::GetEventMessage(lldb::tid_t tid, unsigned long *message)
{
bool result;
EventMessageOperation op(tid, message, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::Detach()
{
bool result;
KillOperation op(result);
DoOperation(&op);
StopMonitor();
return result;
}
bool
ProcessMonitor::DupDescriptor(const char *path, int fd, int flags)
{
int target_fd = open(path, flags);
if (target_fd == -1)
return false;
return (dup2(fd, target_fd) == -1) ? false : true;
}
void
ProcessMonitor::StopMonitoringChildProcess()
{
lldb::thread_result_t thread_result;
if (IS_VALID_LLDB_HOST_THREAD(m_monitor_thread))
{
Host::ThreadCancel(m_monitor_thread, NULL);
Host::ThreadJoin(m_monitor_thread, &thread_result, NULL);
m_monitor_thread = LLDB_INVALID_HOST_THREAD;
}
}
void
ProcessMonitor::StopMonitor()
{
StopMonitoringChildProcess();
StopOperationThread();
CloseFD(m_terminal_fd);
CloseFD(m_client_fd);
CloseFD(m_server_fd);
}
void
ProcessMonitor::CloseFD(int &fd)
{
if (fd != -1)
{
close(fd);
fd = -1;
}
}
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