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llvm-project/lldb/source/Plugins/Process/FreeBSD/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 <stdint.h>
#include <unistd.h>
#include <signal.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 "POSIXThread.h"
#include "ProcessFreeBSD.h"
#include "ProcessPOSIXLog.h"
#include "ProcessMonitor.h"
extern "C" {
extern char ** environ;
}
using namespace lldb;
using namespace lldb_private;
// We disable the tracing of ptrace calls for integration builds to
// avoid the additional indirection and checks.
#ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
// Wrapper for ptrace to catch errors and log calls.
const char *
Get_PT_IO_OP(int op)
{
switch (op) {
case PIOD_READ_D: return "READ_D";
case PIOD_WRITE_D: return "WRITE_D";
case PIOD_READ_I: return "READ_I";
case PIOD_WRITE_I: return "WRITE_I";
default: return "Unknown op";
}
}
// Wrapper for ptrace to catch errors and log calls.
// Note that ptrace sets errno on error because -1 is reserved as a valid result.
extern long
PtraceWrapper(int req, lldb::pid_t pid, void *addr, int data,
const char* reqName, const char* file, int line)
{
long int result;
Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_PTRACE));
if (log) {
log->Printf("ptrace(%s, %lu, %p, %x) called from file %s line %d",
reqName, pid, addr, data, file, line);
if (req == PT_IO) {
struct ptrace_io_desc *pi = (struct ptrace_io_desc *) addr;
log->Printf("PT_IO: op=%s offs=%zx size=%ld",
Get_PT_IO_OP(pi->piod_op), (size_t)pi->piod_offs, pi->piod_len);
}
}
//PtraceDisplayBytes(req, data);
errno = 0;
result = ptrace(req, pid, (caddr_t) addr, data);
//PtraceDisplayBytes(req, data);
if (log && errno != 0)
{
const char* str;
switch (errno)
{
case ESRCH: str = "ESRCH"; break;
case EINVAL: str = "EINVAL"; break;
case EBUSY: str = "EBUSY"; break;
case EPERM: str = "EPERM"; break;
default: str = "<unknown>";
}
log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
}
#ifdef __amd64__
if (log) {
if (req == PT_GETREGS) {
struct reg *r = (struct reg *) addr;
log->Printf("PT_GETREGS: ip=0x%lx", r->r_rip);
log->Printf("PT_GETREGS: sp=0x%lx", r->r_rsp);
log->Printf("PT_GETREGS: bp=0x%lx", r->r_rbp);
log->Printf("PT_GETREGS: ax=0x%lx", r->r_rax);
}
}
#endif
return result;
}
// Wrapper for ptrace when logging is not required.
// Sets errno to 0 prior to calling ptrace.
extern long
PtraceWrapper(int req, lldb::pid_t pid, void *addr, int data)
{
long result = 0;
errno = 0;
result = ptrace(req, pid, (caddr_t)addr, data);
return result;
}
#define PTRACE(req, pid, addr, data) \
PtraceWrapper((req), (pid), (addr), (data), #req, __FILE__, __LINE__)
#else
PtraceWrapper((req), (pid), (addr), (data))
#endif
//------------------------------------------------------------------------------
// 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, lldb::addr_t vm_addr, void *buf, size_t size,
Error &error)
{
struct ptrace_io_desc pi_desc;
pi_desc.piod_op = PIOD_READ_D;
pi_desc.piod_offs = (void *)vm_addr;
pi_desc.piod_addr = buf;
pi_desc.piod_len = size;
if (PTRACE(PT_IO, pid, (caddr_t)&pi_desc, 0) < 0)
error.SetErrorToErrno();
return pi_desc.piod_len;
}
static size_t
DoWriteMemory(lldb::pid_t pid, lldb::addr_t vm_addr, const void *buf,
size_t size, Error &error)
{
struct ptrace_io_desc pi_desc;
pi_desc.piod_op = PIOD_WRITE_D;
pi_desc.piod_offs = (void *)vm_addr;
pi_desc.piod_addr = (void *)buf;
pi_desc.piod_len = size;
if (PTRACE(PT_IO, pid, (caddr_t)&pi_desc, 0) < 0)
error.SetErrorToErrno();
return pi_desc.piod_len;
}
// 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 FreeBSD, 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 ~Operation() {}
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)
{
lldb::pid_t pid = monitor->GetPID();
m_result = DoReadMemory(pid, m_addr, m_buff, m_size, m_error);
}
//------------------------------------------------------------------------------
/// @class WriteOperation
/// @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)
{
lldb::pid_t pid = monitor->GetPID();
m_result = DoWriteMemory(pid, m_addr, m_buff, m_size, m_error);
}
//------------------------------------------------------------------------------
/// @class ReadRegOperation
/// @brief Implements ProcessMonitor::ReadRegisterValue.
class ReadRegOperation : public Operation
{
public:
ReadRegOperation(lldb::tid_t tid, unsigned offset, unsigned size,
RegisterValue &value, bool &result)
: m_tid(tid), m_offset(offset), m_size(size),
m_value(value), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
unsigned m_offset;
unsigned m_size;
RegisterValue &m_value;
bool &m_result;
};
void
ReadRegOperation::Execute(ProcessMonitor *monitor)
{
struct reg regs;
int rc;
if ((rc = PTRACE(PT_GETREGS, m_tid, (caddr_t)&regs, 0)) < 0) {
m_result = false;
} else {
if (m_size == sizeof(uintptr_t))
m_value = *(uintptr_t *)(((caddr_t)&regs) + m_offset);
else
memcpy(&m_value, (((caddr_t)&regs) + m_offset), m_size);
m_result = true;
}
}
//------------------------------------------------------------------------------
/// @class WriteRegOperation
/// @brief Implements ProcessMonitor::WriteRegisterValue.
class WriteRegOperation : public Operation
{
public:
WriteRegOperation(lldb::tid_t tid, unsigned offset,
const RegisterValue &value, bool &result)
: m_tid(tid), m_offset(offset),
m_value(value), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
unsigned m_offset;
const RegisterValue &m_value;
bool &m_result;
};
void
WriteRegOperation::Execute(ProcessMonitor *monitor)
{
struct reg regs;
if (PTRACE(PT_GETREGS, m_tid, (caddr_t)&regs, 0) < 0) {
m_result = false;
return;
}
*(uintptr_t *)(((caddr_t)&regs) + m_offset) = (uintptr_t)m_value.GetAsUInt64();
if (PTRACE(PT_SETREGS, m_tid, (caddr_t)&regs, 0) < 0)
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class ReadGPROperation
/// @brief Implements ProcessMonitor::ReadGPR.
class ReadGPROperation : public Operation
{
public:
ReadGPROperation(lldb::tid_t tid, void *buf, bool &result)
: m_tid(tid), m_buf(buf), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
void *m_buf;
bool &m_result;
};
void
ReadGPROperation::Execute(ProcessMonitor *monitor)
{
int rc;
errno = 0;
rc = PTRACE(PT_GETREGS, m_tid, (caddr_t)m_buf, 0);
if (errno != 0)
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class ReadFPROperation
/// @brief Implements ProcessMonitor::ReadFPR.
class ReadFPROperation : public Operation
{
public:
ReadFPROperation(lldb::tid_t tid, void *buf, bool &result)
: m_tid(tid), m_buf(buf), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
void *m_buf;
bool &m_result;
};
void
ReadFPROperation::Execute(ProcessMonitor *monitor)
{
if (PTRACE(PT_GETFPREGS, m_tid, (caddr_t)m_buf, 0) < 0)
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class WriteGPROperation
/// @brief Implements ProcessMonitor::WriteGPR.
class WriteGPROperation : public Operation
{
public:
WriteGPROperation(lldb::tid_t tid, void *buf, bool &result)
: m_tid(tid), m_buf(buf), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
void *m_buf;
bool &m_result;
};
void
WriteGPROperation::Execute(ProcessMonitor *monitor)
{
if (PTRACE(PT_SETREGS, m_tid, (caddr_t)m_buf, 0) < 0)
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class WriteFPROperation
/// @brief Implements ProcessMonitor::WriteFPR.
class WriteFPROperation : public Operation
{
public:
WriteFPROperation(lldb::tid_t tid, void *buf, bool &result)
: m_tid(tid), m_buf(buf), m_result(result)
{ }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
void *m_buf;
bool &m_result;
};
void
WriteFPROperation::Execute(ProcessMonitor *monitor)
{
if (PTRACE(PT_SETFPREGS, m_tid, (caddr_t)m_buf, 0) < 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(PT_CONTINUE, m_tid, (caddr_t)1, data))
{
Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
if (log)
log->Printf ("ResumeOperation (%" PRIu64 ") failed: %s", m_tid, strerror(errno));
m_result = false;
}
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class SingleStepOperation
/// @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(PT_STEP, m_tid, NULL, data))
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class LwpInfoOperation
/// @brief Implements ProcessMonitor::GetLwpInfo.
class LwpInfoOperation : public Operation
{
public:
LwpInfoOperation(lldb::tid_t tid, void *info, bool &result, int &ptrace_err)
: m_tid(tid), m_info(info), m_result(result), m_err(ptrace_err) { }
void Execute(ProcessMonitor *monitor);
private:
lldb::tid_t m_tid;
void *m_info;
bool &m_result;
int &m_err;
};
void
LwpInfoOperation::Execute(ProcessMonitor *monitor)
{
struct ptrace_lwpinfo plwp;
if (PTRACE(PT_LWPINFO, m_tid, (caddr_t)&plwp, sizeof(plwp))) {
m_result = false;
m_err = errno;
} else {
memcpy(m_info, &plwp, sizeof(plwp));
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)
{
struct ptrace_lwpinfo plwp;
if (PTRACE(PT_LWPINFO, m_tid, (caddr_t)&plwp, sizeof(plwp)))
m_result = false;
else {
if (plwp.pl_flags & PL_FLAG_FORKED) {
m_message = (unsigned long *)plwp.pl_child_pid;
m_result = true;
} else
m_result = false;
}
}
//------------------------------------------------------------------------------
/// @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(PT_KILL, pid, NULL, 0))
m_result = false;
else
m_result = true;
}
//------------------------------------------------------------------------------
/// @class DetachOperation
/// @brief Implements ProcessMonitor::BringProcessIntoLimbo.
class DetachOperation : public Operation
{
public:
DetachOperation(Error &result) : m_error(result) { }
void Execute(ProcessMonitor *monitor);
private:
Error &m_error;
};
void
DetachOperation::Execute(ProcessMonitor *monitor)
{
lldb::pid_t pid = monitor->GetPID();
if (PTRACE(PT_DETACH, pid, NULL, 0) < 0)
m_error.SetErrorToErrno();
}
ProcessMonitor::OperationArgs::OperationArgs(ProcessMonitor *monitor)
: m_monitor(monitor)
{
sem_init(&m_semaphore, 0, 0);
}
ProcessMonitor::OperationArgs::~OperationArgs()
{
sem_destroy(&m_semaphore);
}
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,
const char *working_dir)
: OperationArgs(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),
m_working_dir(working_dir) { }
ProcessMonitor::LaunchArgs::~LaunchArgs()
{ }
ProcessMonitor::AttachArgs::AttachArgs(ProcessMonitor *monitor,
lldb::pid_t pid)
: OperationArgs(monitor), m_pid(pid) { }
ProcessMonitor::AttachArgs::~AttachArgs()
{ }
//------------------------------------------------------------------------------
/// 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 ProcessFreeBSD 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(ProcessPOSIX *process,
Module *module,
const char *argv[],
const char *envp[],
const char *stdin_path,
const char *stdout_path,
const char *stderr_path,
const char *working_dir,
lldb_private::Error &error)
: m_process(static_cast<ProcessFreeBSD *>(process)),
m_operation_thread(LLDB_INVALID_HOST_THREAD),
m_monitor_thread(LLDB_INVALID_HOST_THREAD),
m_pid(LLDB_INVALID_PROCESS_ID),
m_terminal_fd(-1),
m_operation(0)
{
std::unique_ptr<LaunchArgs> args(new LaunchArgs(this, module, argv, envp,
stdin_path, stdout_path, stderr_path,
working_dir));
sem_init(&m_operation_pending, 0, 0);
sem_init(&m_operation_done, 0, 0);
StartLaunchOpThread(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())
{
StopOpThread();
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(ProcessPOSIX *process,
lldb::pid_t pid,
lldb_private::Error &error)
: m_process(static_cast<ProcessFreeBSD *>(process)),
m_operation_thread(LLDB_INVALID_HOST_THREAD),
m_monitor_thread(LLDB_INVALID_HOST_THREAD),
m_pid(pid),
m_terminal_fd(-1),
m_operation(0)
{
sem_init(&m_operation_pending, 0, 0);
sem_init(&m_operation_done, 0, 0);
std::unique_ptr<AttachArgs> args(new AttachArgs(this, pid));
StartAttachOpThread(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 attach was a success.
if (!args->m_error.Success())
{
StopOpThread();
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 attach failed.");
return;
}
}
ProcessMonitor::~ProcessMonitor()
{
StopMonitor();
}
//------------------------------------------------------------------------------
// Thread setup and tear down.
void
ProcessMonitor::StartLaunchOpThread(LaunchArgs *args, Error &error)
{
static const char *g_thread_name = "lldb.process.freebsd.operation";
if (IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
return;
m_operation_thread =
Host::ThreadCreate(g_thread_name, LaunchOpThread, args, &error);
}
void *
ProcessMonitor::LaunchOpThread(void *arg)
{
LaunchArgs *args = static_cast<LaunchArgs*>(arg);
if (!Launch(args)) {
sem_post(&args->m_semaphore);
return NULL;
}
ServeOperation(args);
return NULL;
}
bool
ProcessMonitor::Launch(LaunchArgs *args)
{
ProcessMonitor *monitor = args->m_monitor;
ProcessFreeBSD &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;
const char *working_dir = args->m_working_dir;
lldb_utility::PseudoTerminal terminal;
const size_t err_len = 1024;
char err_str[err_len];
lldb::pid_t pid;
// 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)) == -1)
{
args->m_error.SetErrorToGenericError();
args->m_error.SetErrorString("Process fork failed.");
goto FINISH;
}
// Recognized child exit status codes.
enum {
ePtraceFailed = 1,
eDupStdinFailed,
eDupStdoutFailed,
eDupStderrFailed,
eChdirFailed,
eExecFailed
};
// Child process.
if (pid == 0)
{
// Trace this process.
if (PTRACE(PT_TRACE_ME, 0, NULL, 0) < 0)
exit(ePtraceFailed);
// 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))
exit(eDupStdinFailed);
if (stdout_path != NULL && stdout_path[0])
if (!DupDescriptor(stdout_path, STDOUT_FILENO, O_WRONLY | O_CREAT))
exit(eDupStdoutFailed);
if (stderr_path != NULL && stderr_path[0])
if (!DupDescriptor(stderr_path, STDERR_FILENO, O_WRONLY | O_CREAT))
exit(eDupStderrFailed);
// Change working directory
if (working_dir != NULL && working_dir[0])
if (0 != ::chdir(working_dir))
exit(eChdirFailed);
// Execute. We should never return.
execve(argv[0],
const_cast<char *const *>(argv),
const_cast<char *const *>(envp));
exit(eExecFailed);
}
// Wait for the child process to to trap on its call to execve.
::pid_t wpid;
int status;
if ((wpid = waitpid(pid, &status, 0)) < 0)
{
args->m_error.SetErrorToErrno();
goto FINISH;
}
else if (WIFEXITED(status))
{
// open, dup or execve likely failed for some reason.
args->m_error.SetErrorToGenericError();
switch (WEXITSTATUS(status))
{
case ePtraceFailed:
args->m_error.SetErrorString("Child ptrace failed.");
break;
case eDupStdinFailed:
args->m_error.SetErrorString("Child open stdin failed.");
break;
case eDupStdoutFailed:
args->m_error.SetErrorString("Child open stdout failed.");
break;
case eDupStderrFailed:
args->m_error.SetErrorString("Child open stderr failed.");
break;
case eChdirFailed:
args->m_error.SetErrorString("Child failed to set working directory.");
break;
case eExecFailed:
args->m_error.SetErrorString("Child exec failed.");
break;
default:
args->m_error.SetErrorString("Child returned unknown exit status.");
break;
}
goto FINISH;
}
assert(WIFSTOPPED(status) && wpid == pid &&
"Could not sync with inferior process.");
#ifdef notyet
// 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;
}
#endif
// 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 ProcessFreeBSD::GetSTDOUT to have a non-blocking
// descriptor to read from).
if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
goto FINISH;
process.SendMessage(ProcessMessage::Attach(pid));
FINISH:
return args->m_error.Success();
}
void
ProcessMonitor::StartAttachOpThread(AttachArgs *args, lldb_private::Error &error)
{
static const char *g_thread_name = "lldb.process.freebsd.operation";
if (IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
return;
m_operation_thread =
Host::ThreadCreate(g_thread_name, AttachOpThread, args, &error);
}
void *
ProcessMonitor::AttachOpThread(void *arg)
{
AttachArgs *args = static_cast<AttachArgs*>(arg);
if (!Attach(args))
return NULL;
ServeOperation(args);
return NULL;
}
bool
ProcessMonitor::Attach(AttachArgs *args)
{
lldb::pid_t pid = args->m_pid;
ProcessMonitor *monitor = args->m_monitor;
ProcessFreeBSD &process = monitor->GetProcess();
if (pid <= 1)
{
args->m_error.SetErrorToGenericError();
args->m_error.SetErrorString("Attaching to process 1 is not allowed.");
goto FINISH;
}
// Attach to the requested process.
if (PTRACE(PT_ATTACH, pid, NULL, 0) < 0)
{
args->m_error.SetErrorToErrno();
goto FINISH;
}
int status;
if ((status = waitpid(pid, NULL, 0)) < 0)
{
args->m_error.SetErrorToErrno();
goto FINISH;
}
process.SendMessage(ProcessMessage::Attach(pid));
FINISH:
return args->m_error.Success();
}
bool
ProcessMonitor::MonitorCallback(void *callback_baton,
lldb::pid_t pid,
bool exited,
int signal,
int status)
{
ProcessMessage message;
ProcessMonitor *monitor = static_cast<ProcessMonitor*>(callback_baton);
ProcessFreeBSD *process = monitor->m_process;
assert(process);
bool stop_monitoring;
struct ptrace_lwpinfo plwp;
int ptrace_err;
Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
if (exited)
{
if (log)
log->Printf ("ProcessMonitor::%s() got exit signal, tid = %" PRIu64, __FUNCTION__, pid);
message = ProcessMessage::Exit(pid, status);
process->SendMessage(message);
return pid == process->GetID();
}
if (!monitor->GetLwpInfo(pid, &plwp, ptrace_err))
stop_monitoring = true; // pid is gone. Bail.
else {
switch (plwp.pl_siginfo.si_signo)
{
case SIGTRAP:
message = MonitorSIGTRAP(monitor, &plwp.pl_siginfo, pid);
break;
default:
message = MonitorSignal(monitor, &plwp.pl_siginfo, pid);
break;
}
process->SendMessage(message);
stop_monitoring = message.GetKind() == ProcessMessage::eExitMessage;
}
return stop_monitoring;
}
ProcessMessage
ProcessMonitor::MonitorSIGTRAP(ProcessMonitor *monitor,
const siginfo_t *info, lldb::pid_t pid)
{
ProcessMessage message;
Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
assert(monitor);
assert(info && 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;
if (log)
log->Printf ("ProcessMonitor::%s() received exit? event, data = %lx, pid = %" PRIu64, __FUNCTION__, data, pid);
message = ProcessMessage::Limbo(pid, (data >> 8));
break;
}
case 0:
case TRAP_TRACE:
if (log)
log->Printf ("ProcessMonitor::%s() received trace event, pid = %" PRIu64, __FUNCTION__, pid);
message = ProcessMessage::Trace(pid);
break;
case SI_KERNEL:
case TRAP_BRKPT:
if (log)
log->Printf ("ProcessMonitor::%s() received breakpoint event, pid = %" PRIu64, __FUNCTION__, pid);
message = ProcessMessage::Break(pid);
break;
}
return message;
}
ProcessMessage
ProcessMonitor::MonitorSignal(ProcessMonitor *monitor,
const siginfo_t *info, lldb::pid_t pid)
{
ProcessMessage message;
int signo = info->si_signo;
Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
// 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 FreeBSD.
//
// 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_USER)
{
if (log)
log->Printf ("ProcessMonitor::%s() received signal %s with code %s, pid = %d",
__FUNCTION__,
monitor->m_process->GetUnixSignals().GetSignalAsCString (signo),
"SI_USER",
info->si_pid);
if (info->si_pid == getpid())
return ProcessMessage::SignalDelivered(pid, signo);
else
return ProcessMessage::Signal(pid, signo);
}
if (log)
log->Printf ("ProcessMonitor::%s() received signal %s", __FUNCTION__, monitor->m_process->GetUnixSignals().GetSignalAsCString (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 siginfo_t *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 siginfo_t *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 siginfo_t *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 siginfo_t *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(OperationArgs *args)
{
int status;
ProcessMonitor *monitor = args->m_monitor;
// 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 (;;)
{
// wait for next pending operation
sem_wait(&monitor->m_operation_pending);
monitor->m_operation->Execute(monitor);
// notify calling thread that operation is complete
sem_post(&monitor->m_operation_done);
}
}
void
ProcessMonitor::DoOperation(Operation *op)
{
Mutex::Locker lock(m_operation_mutex);
m_operation = op;
// notify operation thread that an operation is ready to be processed
sem_post(&m_operation_pending);
// wait for operation to complete
sem_wait(&m_operation_done);
}
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(lldb::tid_t tid, unsigned offset, const char* reg_name,
unsigned size, RegisterValue &value)
{
bool result;
ReadRegOperation op(tid, offset, size, value, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::WriteRegisterValue(lldb::tid_t tid, unsigned offset,
const char* reg_name, const RegisterValue &value)
{
bool result;
WriteRegOperation op(tid, offset, value, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
{
bool result;
ReadGPROperation op(tid, buf, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size)
{
bool result;
ReadFPROperation op(tid, buf, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
{
return false;
}
bool
ProcessMonitor::WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size)
{
bool result;
WriteGPROperation op(tid, buf, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size)
{
bool result;
WriteFPROperation op(tid, buf, result);
DoOperation(&op);
return result;
}
bool
ProcessMonitor::WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
{
return false;
}
bool
ProcessMonitor::Resume(lldb::tid_t tid, uint32_t signo)
{
bool result;
Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PROCESS));
if (log)
log->Printf ("ProcessMonitor::%s() resuming thread = %" PRIu64 " with signal %s", __FUNCTION__, tid,
m_process->GetUnixSignals().GetSignalAsCString (signo));
ResumeOperation op(tid, signo, result);
DoOperation(&op);
if (log)
log->Printf ("ProcessMonitor::%s() resuming result = %s", __FUNCTION__, result ? "true" : "false");
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::GetLwpInfo(lldb::tid_t tid, void *lwpinfo, int &ptrace_err)
{
bool result;
LwpInfoOperation op(tid, lwpinfo, result, ptrace_err);
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;
}
lldb_private::Error
ProcessMonitor::Detach(lldb::tid_t tid)
{
lldb_private::Error error;
if (tid != LLDB_INVALID_THREAD_ID)
{
DetachOperation op(error);
DoOperation(&op);
}
return error;
}
bool
ProcessMonitor::DupDescriptor(const char *path, int fd, int flags)
{
int target_fd = open(path, flags, 0666);
if (target_fd == -1)
return false;
return (dup2(target_fd, 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();
StopOpThread();
sem_destroy(&m_operation_pending);
sem_destroy(&m_operation_done);
// Note: ProcessPOSIX passes the m_terminal_fd file descriptor to
// Process::SetSTDIOFileDescriptor, which in turn transfers ownership of
// the descriptor to a ConnectionFileDescriptor object. Consequently
// even though still has the file descriptor, we shouldn't close it here.
}
// FIXME: On Linux, when a new thread is created, we receive to notifications,
// (1) a SIGTRAP|PTRACE_EVENT_CLONE from the main process thread with the
// child thread id as additional information, and (2) a SIGSTOP|SI_USER from
// the new child thread indicating that it has is stopped because we attached.
// We have no guarantee of the order in which these arrive, but we need both
// before we are ready to proceed. We currently keep a list of threads which
// have sent the initial SIGSTOP|SI_USER event. Then when we receive the
// SIGTRAP|PTRACE_EVENT_CLONE notification, if the initial stop has not occurred
// we call ProcessMonitor::WaitForInitialTIDStop() to wait for it.
//
// Right now, the above logic is in ProcessPOSIX, so we need a definition of
// this function in the FreeBSD ProcessMonitor implementation even if it isn't
// logically needed.
//
// We really should figure out what actually happens on FreeBSD and move the
// Linux-specific logic out of ProcessPOSIX as needed.
bool
ProcessMonitor::WaitForInitialTIDStop(lldb::tid_t tid)
{
return true;
}
void
ProcessMonitor::StopOpThread()
{
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);
m_operation_thread = LLDB_INVALID_HOST_THREAD;
}
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