//===-- NativeProcessFreeBSD.cpp ------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "NativeProcessFreeBSD.h"
// clang-format off
#include <sys/types.h>
#include <sys/ptrace.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <sys/wait.h>
#include <machine/elf.h>
// clang-format on
#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
#include "lldb/Host/HostProcess.h"
#include "lldb/Host/posix/ProcessLauncherPosixFork.h"
#include "lldb/Target/Process.h"
#include "lldb/Utility/State.h"
#include "llvm/Support/Errno.h"
using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::process_freebsd;
using namespace llvm;
// Simple helper function to ensure flags are enabled on the given file
// descriptor.
static Status EnsureFDFlags(int fd, int flags) {
Status error;
int status = fcntl(fd, F_GETFL);
if (status == -1) {
error = Status::FromErrno();
return error;
}
if (fcntl(fd, F_SETFL, status | flags) == -1) {
error = Status::FromErrno();
return error;
}
return error;
}
static Status CanTrace() {
int proc_debug, ret;
size_t len = sizeof(proc_debug);
ret = ::sysctlbyname("security.bsd.unprivileged_proc_debug", &proc_debug,
&len, nullptr, 0);
if (ret != 0)
return Status::FromErrorString(
"sysctlbyname() security.bsd.unprivileged_proc_debug failed");
if (proc_debug < 1)
return Status::FromErrorString(
"process debug disabled by security.bsd.unprivileged_proc_debug oid");
return {};
}
// Public Static Methods
llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
NativeProcessFreeBSD::Manager::Launch(ProcessLaunchInfo &launch_info,
NativeDelegate &native_delegate) {
Log *log = GetLog(POSIXLog::Process);
Status status;
::pid_t pid = ProcessLauncherPosixFork()
.LaunchProcess(launch_info, status)
.GetProcessId();
LLDB_LOG(log, "pid = {0:x}", pid);
if (status.Fail()) {
LLDB_LOG(log, "failed to launch process: {0}", status);
auto error = CanTrace();
if (error.Fail())
return error.ToError();
return status.ToError();
}
// Wait for the child process to trap on its call to execve.
int wstatus;
::pid_t wpid = llvm::sys::RetryAfterSignal(-1, ::waitpid, pid, &wstatus, 0);
assert(wpid == pid);
UNUSED_IF_ASSERT_DISABLED(wpid);
if (!WIFSTOPPED(wstatus)) {
LLDB_LOG(log, "Could not sync with inferior process: wstatus={1}",
WaitStatus::Decode(wstatus));
return llvm::make_error<StringError>("Could not sync with inferior process",
llvm::inconvertibleErrorCode());
}
LLDB_LOG(log, "inferior started, now in stopped state");
ProcessInstanceInfo Info;
if (!Host::GetProcessInfo(pid, Info)) {
return llvm::make_error<StringError>("Cannot get process architecture",
llvm::inconvertibleErrorCode());
}
// Set the architecture to the exe architecture.
LLDB_LOG(log, "pid = {0:x}, detected architecture {1}", pid,
Info.GetArchitecture().GetArchitectureName());
std::unique_ptr<NativeProcessFreeBSD> process_up(new NativeProcessFreeBSD(
pid, launch_info.GetPTY().ReleasePrimaryFileDescriptor(), native_delegate,
Info.GetArchitecture(), m_mainloop));
status = process_up->SetupTrace();
if (status.Fail())
return status.ToError();
for (const auto &thread : process_up->m_threads)
static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
process_up->SetState(StateType::eStateStopped, false);
return std::move(process_up);
}
llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
NativeProcessFreeBSD::Manager::Attach(
lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate) {
Log *log = GetLog(POSIXLog::Process);
LLDB_LOG(log, "pid = {0:x}", pid);
// Retrieve the architecture for the running process.
ProcessInstanceInfo Info;
if (!Host::GetProcessInfo(pid, Info)) {
return llvm::make_error<StringError>("Cannot get process architecture",
llvm::inconvertibleErrorCode());
}
std::unique_ptr<NativeProcessFreeBSD> process_up(new NativeProcessFreeBSD(
pid, -1, native_delegate, Info.GetArchitecture(), m_mainloop));
Status status = process_up->Attach();
if (!status.Success())
return status.ToError();
return std::move(process_up);
}
NativeProcessFreeBSD::Extension
NativeProcessFreeBSD::Manager::GetSupportedExtensions() const {
return
#if defined(PT_COREDUMP)
Extension::savecore |
#endif
Extension::multiprocess | Extension::fork | Extension::vfork |
Extension::pass_signals | Extension::auxv | Extension::libraries_svr4 |
Extension::siginfo_read;
}
// Public Instance Methods
NativeProcessFreeBSD::NativeProcessFreeBSD(::pid_t pid, int terminal_fd,
NativeDelegate &delegate,
const ArchSpec &arch,
MainLoop &mainloop)
: NativeProcessELF(pid, terminal_fd, delegate), m_arch(arch),
m_main_loop(mainloop) {
if (m_terminal_fd != -1) {
Status status = EnsureFDFlags(m_terminal_fd, O_NONBLOCK);
assert(status.Success());
}
Status status;
m_sigchld_handle = mainloop.RegisterSignal(
SIGCHLD, [this](MainLoopBase &) { SigchldHandler(); }, status);
assert(m_sigchld_handle && status.Success());
}
// Handles all waitpid events from the inferior process.
void NativeProcessFreeBSD::MonitorCallback(lldb::pid_t pid, int signal) {
switch (signal) {
case SIGTRAP:
return MonitorSIGTRAP(pid);
case SIGSTOP:
return MonitorSIGSTOP(pid);
default:
return MonitorSignal(pid, signal);
}
}
void NativeProcessFreeBSD::MonitorExited(lldb::pid_t pid, WaitStatus status) {
Log *log = GetLog(POSIXLog::Process);
LLDB_LOG(log, "got exit signal({0}) , pid = {1}", status, pid);
/* Stop Tracking All Threads attached to Process */
m_threads.clear();
SetExitStatus(status, true);
// Notify delegate that our process has exited.
SetState(StateType::eStateExited, true);
}
void NativeProcessFreeBSD::MonitorSIGSTOP(lldb::pid_t pid) {
/* Stop all Threads attached to Process */
for (const auto &thread : m_threads) {
static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP,
nullptr);
}
SetState(StateType::eStateStopped, true);
}
void NativeProcessFreeBSD::MonitorSIGTRAP(lldb::pid_t pid) {
Log *log = GetLog(POSIXLog::Process);
struct ptrace_lwpinfo info;
const auto siginfo_err = PtraceWrapper(PT_LWPINFO, pid, &info, sizeof(info));
if (siginfo_err.Fail()) {
LLDB_LOG(log, "PT_LWPINFO failed {0}", siginfo_err);
return;
}
assert(info.pl_event == PL_EVENT_SIGNAL);
LLDB_LOG(log, "got SIGTRAP, pid = {0}, lwpid = {1}, flags = {2:x}", pid,
info.pl_lwpid, info.pl_flags);
NativeThreadFreeBSD *thread = nullptr;
if (info.pl_flags & (PL_FLAG_BORN | PL_FLAG_EXITED)) {
if (info.pl_flags & PL_FLAG_BORN) {
LLDB_LOG(log, "monitoring new thread, tid = {0}", info.pl_lwpid);
NativeThreadFreeBSD &t = AddThread(info.pl_lwpid);
// Technically, the FreeBSD kernel copies the debug registers to new
// threads. However, there is a non-negligible delay between acquiring
// the DR values and reporting the new thread during which the user may
// establish a new watchpoint. In order to ensure that watchpoints
// established during this period are propagated to new threads,
// explicitly copy the DR value at the time the new thread is reported.
//
// See also: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=250954
llvm::Error error = t.CopyWatchpointsFrom(
static_cast<NativeThreadFreeBSD &>(*GetCurrentThread()));
if (error) {
LLDB_LOG_ERROR(log, std::move(error),
"failed to copy watchpoints to new thread {1}: {0}",
info.pl_lwpid);
SetState(StateType::eStateInvalid);
return;
}
} else /*if (info.pl_flags & PL_FLAG_EXITED)*/ {
LLDB_LOG(log, "thread exited, tid = {0}", info.pl_lwpid);
RemoveThread(info.pl_lwpid);
}
Status error =
PtraceWrapper(PT_CONTINUE, pid, reinterpret_cast<void *>(1), 0);
if (error.Fail())
SetState(StateType::eStateInvalid);
return;
}
if (info.pl_flags & PL_FLAG_EXEC) {
Status error = ReinitializeThreads();
if (error.Fail()) {
SetState(StateType::eStateInvalid);
return;
}
// Let our delegate know we have just exec'd.
NotifyDidExec();
for (const auto &thread : m_threads)
static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedByExec();
SetCurrentThreadID(m_threads.front()->GetID());
SetState(StateType::eStateStopped, true);
return;
}
if (info.pl_lwpid > 0) {
for (const auto &t : m_threads) {
if (t->GetID() == static_cast<lldb::tid_t>(info.pl_lwpid))
thread = static_cast<NativeThreadFreeBSD *>(t.get());
static_cast<NativeThreadFreeBSD *>(t.get())->SetStoppedWithNoReason();
}
if (!thread)
LLDB_LOG(log, "thread not found in m_threads, pid = {0}, LWP = {1}", pid,
info.pl_lwpid);
}
if (info.pl_flags & PL_FLAG_FORKED) {
assert(thread);
MonitorClone(info.pl_child_pid, info.pl_flags & PL_FLAG_VFORKED, *thread);
return;
}
if (info.pl_flags & PL_FLAG_VFORK_DONE) {
assert(thread);
if ((m_enabled_extensions & Extension::vfork) == Extension::vfork) {
thread->SetStoppedByVForkDone();
SetState(StateType::eStateStopped, true);
} else {
Status error =
PtraceWrapper(PT_CONTINUE, pid, reinterpret_cast<void *>(1), 0);
if (error.Fail())
SetState(StateType::eStateInvalid);
}
return;
}
if (info.pl_flags & PL_FLAG_SI) {
assert(info.pl_siginfo.si_signo == SIGTRAP);
LLDB_LOG(log, "SIGTRAP siginfo: si_code = {0}, pid = {1}",
info.pl_siginfo.si_code, info.pl_siginfo.si_pid);
switch (info.pl_siginfo.si_code) {
case TRAP_BRKPT:
LLDB_LOG(log, "SIGTRAP/TRAP_BRKPT: si_addr: {0}",
info.pl_siginfo.si_addr);
if (thread) {
auto ®ctx = static_cast<NativeRegisterContextFreeBSD &>(
thread->GetRegisterContext());
auto thread_info =
m_threads_stepping_with_breakpoint.find(thread->GetID());
if (thread_info != m_threads_stepping_with_breakpoint.end() &&
threads_info->second == regctx.GetPC()) {
thread->SetStoppedByTrace();
Status brkpt_error = RemoveBreakpoint(thread_info->second);
if (brkpt_error.Fail())
LLDB_LOG(log, "pid = {0} remove stepping breakpoint: {1}",
thread_info->first, brkpt_error);
m_threads_stepping_with_breakpoint.erase(thread_info);
} else
thread->SetStoppedByBreakpoint();
FixupBreakpointPCAsNeeded(*thread);
SetCurrentThreadID(thread->GetID());
}
SetState(StateType::eStateStopped, true);
return;
case TRAP_TRACE:
LLDB_LOG(log, "SIGTRAP/TRAP_TRACE: si_addr: {0}",
info.pl_siginfo.si_addr);
if (thread) {
auto ®ctx = static_cast<NativeRegisterContextFreeBSD &>(
thread->GetRegisterContext());
uint32_t wp_index = LLDB_INVALID_INDEX32;
Status error = regctx.GetWatchpointHitIndex(
wp_index, reinterpret_cast<uintptr_t>(info.pl_siginfo.si_addr));
if (error.Fail())
LLDB_LOG(log,
"received error while checking for watchpoint hits, pid = "
"{0}, LWP = {1}, error = {2}",
pid, info.pl_lwpid, error);
if (wp_index != LLDB_INVALID_INDEX32) {
regctx.ClearWatchpointHit(wp_index);
thread->SetStoppedByWatchpoint(wp_index);
SetCurrentThreadID(thread->GetID());
SetState(StateType::eStateStopped, true);
break;
}
thread->SetStoppedByTrace();
SetCurrentThreadID(thread->GetID());
}
SetState(StateType::eStateStopped, true);
return;
}
}
// Either user-generated SIGTRAP or an unknown event that would
// otherwise leave the debugger hanging.
LLDB_LOG(log, "unknown SIGTRAP, passing to generic handler");
MonitorSignal(pid, SIGTRAP);
}
void NativeProcessFreeBSD::MonitorSignal(lldb::pid_t pid, int signal) {
Log *log = GetLog(POSIXLog::Process);
struct ptrace_lwpinfo info;
const auto siginfo_err = PtraceWrapper(PT_LWPINFO, pid, &info, sizeof(info));
if (siginfo_err.Fail()) {
LLDB_LOG(log, "PT_LWPINFO failed {0}", siginfo_err);
return;
}
assert(info.pl_event == PL_EVENT_SIGNAL);
// TODO: do we need to handle !PL_FLAG_SI?
assert(info.pl_flags & PL_FLAG_SI);
assert(info.pl_siginfo.si_signo == signal);
for (const auto &abs_thread : m_threads) {
NativeThreadFreeBSD &thread =
static_cast<NativeThreadFreeBSD &>(*abs_thread);
assert(info.pl_lwpid >= 0);
if (info.pl_lwpid == 0 ||
static_cast<lldb::tid_t>(info.pl_lwpid) == thread.GetID()) {
thread.SetStoppedBySignal(info.pl_siginfo.si_signo, &info.pl_siginfo);
SetCurrentThreadID(thread.GetID());
} else
thread.SetStoppedWithNoReason();
}
SetState(StateType::eStateStopped, true);
}
Status NativeProcessFreeBSD::PtraceWrapper(int req, lldb::pid_t pid, void *addr,
int data, int *result) {
Log *log = GetLog(POSIXLog::Ptrace);
Status error;
int ret;
errno = 0;
ret =
ptrace(req, static_cast<::pid_t>(pid), static_cast<caddr_t>(addr), data);
if (ret == -1) {
error = CanTrace();
if (error.Success())
error = Status::FromErrno();
}
if (result)
*result = ret;
LLDB_LOG(log, "ptrace({0}, {1}, {2}, {3})={4:x}", req, pid, addr, data, ret);
if (error.Fail())
LLDB_LOG(log, "ptrace() failed: {0}", error);
return error;
}
llvm::Expected<llvm::ArrayRef<uint8_t>>
NativeProcessFreeBSD::GetSoftwareBreakpointTrapOpcode(size_t size_hint) {
static const uint8_t g_arm_opcode[] = {0xfe, 0xde, 0xff, 0xe7};
static const uint8_t g_thumb_opcode[] = {0x01, 0xde};
switch (GetArchitecture().GetMachine()) {
case llvm::Triple::arm:
switch (size_hint) {
case 2:
return llvm::ArrayRef(g_thumb_opcode);
case 4:
return llvm::ArrayRef(g_arm_opcode);
default:
return llvm::createStringError(llvm::inconvertibleErrorCode(),
"Unrecognised trap opcode size hint!");
}
default:
return NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode(size_hint);
}
}
Status NativeProcessFreeBSD::Resume(const ResumeActionList &resume_actions) {
Log *log = GetLog(POSIXLog::Process);
LLDB_LOG(log, "pid {0}", GetID());
Status ret;
int signal = 0;
for (const auto &abs_thread : m_threads) {
assert(abs_thread && "thread list should not contain NULL threads");
NativeThreadFreeBSD &thread =
static_cast<NativeThreadFreeBSD &>(*abs_thread);
const ResumeAction *action =
resume_actions.GetActionForThread(thread.GetID(), true);
// we need to explicit issue suspend requests, so it is simpler to map it
// into proper action
ResumeAction suspend_action{thread.GetID(), eStateSuspended,
LLDB_INVALID_SIGNAL_NUMBER};
if (action == nullptr) {
LLDB_LOG(log, "no action specified for pid {0} tid {1}", GetID(),
thread.GetID());
action = &suspend_action;
}
LLDB_LOG(
log,
"processing resume action state {0} signal {1} for pid {2} tid {3}",
action->state, action->signal, GetID(), thread.GetID());
switch (action->state) {
case eStateRunning:
ret = thread.Resume();
break;
case eStateStepping:
ret = thread.SingleStep();
break;
case eStateSuspended:
case eStateStopped:
if (action->signal != LLDB_INVALID_SIGNAL_NUMBER)
return Status::FromErrorString(
"Passing signal to suspended thread unsupported");
ret = thread.Suspend();
break;
default:
return Status::FromErrorStringWithFormat(
"NativeProcessFreeBSD::%s (): unexpected state %s specified "
"for pid %" PRIu64 ", tid %" PRIu64,
__FUNCTION__, StateAsCString(action->state), GetID(), thread.GetID());
}
if (!ret.Success())
return ret;
if (action->signal != LLDB_INVALID_SIGNAL_NUMBER)
signal = action->signal;
}
ret =
PtraceWrapper(PT_CONTINUE, GetID(), reinterpret_cast<void *>(1), signal);
if (ret.Success())
SetState(eStateRunning, true);
return ret;
}
Status NativeProcessFreeBSD::Halt() {
Status error;
// Do not try to stop a process that's already stopped, this may cause
// the SIGSTOP to get queued and stop the process again once resumed.
if (StateIsStoppedState(m_state, false))
return error;
if (kill(GetID(), SIGSTOP) != 0)
error = Status::FromErrno();
return error;
}
Status NativeProcessFreeBSD::Detach() {
Status error;
// Stop monitoring the inferior.
m_sigchld_handle.reset();
// Tell ptrace to detach from the process.
if (GetID() == LLDB_INVALID_PROCESS_ID)
return error;
return PtraceWrapper(PT_DETACH, GetID());
}
Status NativeProcessFreeBSD::Signal(int signo) {
Status error;
if (kill(GetID(), signo))
error = Status::FromErrno();
return error;
}
Status NativeProcessFreeBSD::Interrupt() { return Halt(); }
Status NativeProcessFreeBSD::Kill() {
Log *log = GetLog(POSIXLog::Process);
LLDB_LOG(log, "pid {0}", GetID());
Status error;
switch (m_state) {
case StateType::eStateInvalid:
case StateType::eStateExited:
case StateType::eStateCrashed:
case StateType::eStateDetached:
case StateType::eStateUnloaded:
// Nothing to do - the process is already dead.
LLDB_LOG(log, "ignored for PID {0} due to current state: {1}", GetID(),
StateAsCString(m_state));
return error;
case StateType::eStateConnected:
case StateType::eStateAttaching:
case StateType::eStateLaunching:
case StateType::eStateStopped:
case StateType::eStateRunning:
case StateType::eStateStepping:
case StateType::eStateSuspended:
// We can try to kill a process in these states.
break;
}
return PtraceWrapper(PT_KILL, m_pid);
}
Status NativeProcessFreeBSD::GetMemoryRegionInfo(lldb::addr_t load_addr,
MemoryRegionInfo &range_info) {
if (m_supports_mem_region == LazyBool::eLazyBoolNo) {
// We're done.
return Status::FromErrorString("unsupported");
}
Status error = PopulateMemoryRegionCache();
if (error.Fail()) {
return error;
}
lldb::addr_t prev_base_address = 0;
// FIXME start by finding the last region that is <= target address using
// binary search. Data is sorted.
// There can be a ton of regions on pthreads apps with lots of threads.
for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end();
++it) {
MemoryRegionInfo &proc_entry_info = it->first;
// Sanity check assumption that memory map entries are ascending.
assert((proc_entry_info.GetRange().GetRangeBase() >= prev_base_address) &&
"descending memory map entries detected, unexpected");
prev_base_address = proc_entry_info.GetRange().GetRangeBase();
UNUSED_IF_ASSERT_DISABLED(prev_base_address);
// If the target address comes before this entry, indicate distance to next
// region.
if (load_addr < proc_entry_info.GetRange().GetRangeBase()) {
range_info.GetRange().SetRangeBase(load_addr);
range_info.GetRange().SetByteSize(
proc_entry_info.GetRange().GetRangeBase() - load_addr);
range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo);
return error;
} else if (proc_entry_info.GetRange().Contains(load_addr)) {
// The target address is within the memory region we're processing here.
range_info = proc_entry_info;
return error;
}
// The target memory address comes somewhere after the region we just
// parsed.
}
// If we made it here, we didn't find an entry that contained the given
// address. Return the load_addr as start and the amount of bytes betwwen
// load address and the end of the memory as size.
range_info.GetRange().SetRangeBase(load_addr);
range_info.GetRange().SetRangeEnd(LLDB_INVALID_ADDRESS);
range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo);
return error;
}
Status NativeProcessFreeBSD::PopulateMemoryRegionCache() {
Log *log = GetLog(POSIXLog::Process);
// If our cache is empty, pull the latest. There should always be at least
// one memory region if memory region handling is supported.
if (!m_mem_region_cache.empty()) {
LLDB_LOG(log, "reusing {0} cached memory region entries",
m_mem_region_cache.size());
return Status();
}
int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, static_cast<int>(m_pid)};
int ret;
size_t len;
ret = ::sysctl(mib, 4, nullptr, &len, nullptr, 0);
if (ret != 0) {
m_supports_mem_region = LazyBool::eLazyBoolNo;
return Status::FromErrorString("sysctl() for KERN_PROC_VMMAP failed");
}
std::unique_ptr<WritableMemoryBuffer> buf =
llvm::WritableMemoryBuffer::getNewMemBuffer(len);
ret = ::sysctl(mib, 4, buf->getBufferStart(), &len, nullptr, 0);
if (ret != 0) {
m_supports_mem_region = LazyBool::eLazyBoolNo;
return Status::FromErrorString("sysctl() for KERN_PROC_VMMAP failed");
}
char *bp = buf->getBufferStart();
char *end = bp + len;
while (bp < end) {
auto *kv = reinterpret_cast<struct kinfo_vmentry *>(bp);
if (kv->kve_structsize == 0)
break;
bp += kv->kve_structsize;
MemoryRegionInfo info;
info.Clear();
info.GetRange().SetRangeBase(kv->kve_start);
info.GetRange().SetRangeEnd(kv->kve_end);
info.SetMapped(MemoryRegionInfo::OptionalBool::eYes);
if (kv->kve_protection & VM_PROT_READ)
info.SetReadable(MemoryRegionInfo::OptionalBool::eYes);
else
info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
if (kv->kve_protection & VM_PROT_WRITE)
info.SetWritable(MemoryRegionInfo::OptionalBool::eYes);
else
info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
if (kv->kve_protection & VM_PROT_EXECUTE)
info.SetExecutable(MemoryRegionInfo::OptionalBool::eYes);
else
info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
if (kv->kve_path[0])
info.SetName(kv->kve_path);
m_mem_region_cache.emplace_back(info,
FileSpec(info.GetName().GetCString()));
}
if (m_mem_region_cache.empty()) {
// No entries after attempting to read them. This shouldn't happen. Assume
// we don't support map entries.
LLDB_LOG(log, "failed to find any vmmap entries, assuming no support "
"for memory region metadata retrieval");
m_supports_mem_region = LazyBool::eLazyBoolNo;
return Status::FromErrorString("not supported");
}
LLDB_LOG(log, "read {0} memory region entries from process {1}",
m_mem_region_cache.size(), GetID());
// We support memory retrieval, remember that.
m_supports_mem_region = LazyBool::eLazyBoolYes;
return Status();
}
size_t NativeProcessFreeBSD::UpdateThreads() { return m_threads.size(); }
Status NativeProcessFreeBSD::SetBreakpoint(lldb::addr_t addr, uint32_t size,
bool hardware) {
if (hardware)
return SetHardwareBreakpoint(addr, size);
return SetSoftwareBreakpoint(addr, size);
}
Status NativeProcessFreeBSD::GetLoadedModuleFileSpec(const char *module_path,
FileSpec &file_spec) {
Status error = PopulateMemoryRegionCache();
if (error.Fail()) {
auto status = CanTrace();
if (status.Fail())
return status;
return error;
}
FileSpec module_file_spec(module_path);
FileSystem::Instance().Resolve(module_file_spec);
file_spec.Clear();
for (const auto &it : m_mem_region_cache) {
if (it.second.GetFilename() == module_file_spec.GetFilename()) {
file_spec = it.second;
return Status();
}
}
return Status::FromErrorStringWithFormat(
"Module file (%s) not found in process' memory map!",
module_file_spec.GetFilename().AsCString());
}
Status
NativeProcessFreeBSD::GetFileLoadAddress(const llvm::StringRef &file_name,
lldb::addr_t &load_addr) {
load_addr = LLDB_INVALID_ADDRESS;
Status error = PopulateMemoryRegionCache();
if (error.Fail()) {
auto status = CanTrace();
if (status.Fail())
return status;
return error;
}
FileSpec file(file_name);
for (const auto &it : m_mem_region_cache) {
if (it.second == file) {
load_addr = it.first.GetRange().GetRangeBase();
return Status();
}
}
return Status::FromErrorStringWithFormat("No load address found for file %s.",
file_name.str().c_str());
}
void NativeProcessFreeBSD::SigchldHandler() {
Log *log = GetLog(POSIXLog::Process);
int status;
::pid_t wait_pid =
llvm::sys::RetryAfterSignal(-1, waitpid, GetID(), &status, WNOHANG);
if (wait_pid == 0)
return;
if (wait_pid == -1) {
Status error(errno, eErrorTypePOSIX);
LLDB_LOG(log, "waitpid ({0}, &status, _) failed: {1}", GetID(), error);
return;
}
WaitStatus wait_status = WaitStatus::Decode(status);
bool exited = wait_status.type == WaitStatus::Exit ||
(wait_status.type == WaitStatus::Signal &&
wait_pid == static_cast<::pid_t>(GetID()));
LLDB_LOG(log,
"waitpid ({0}, &status, _) => pid = {1}, status = {2}, exited = {3}",
GetID(), wait_pid, status, exited);
if (exited)
MonitorExited(wait_pid, wait_status);
else {
assert(wait_status.type == WaitStatus::Stop);
MonitorCallback(wait_pid, wait_status.status);
}
}
bool NativeProcessFreeBSD::HasThreadNoLock(lldb::tid_t thread_id) {
for (const auto &thread : m_threads) {
assert(thread && "thread list should not contain NULL threads");
if (thread->GetID() == thread_id) {
// We have this thread.
return true;
}
}
// We don't have this thread.
return false;
}
NativeThreadFreeBSD &NativeProcessFreeBSD::AddThread(lldb::tid_t thread_id) {
Log *log = GetLog(POSIXLog::Thread);
LLDB_LOG(log, "pid {0} adding thread with tid {1}", GetID(), thread_id);
assert(thread_id > 0);
assert(!HasThreadNoLock(thread_id) &&
"attempted to add a thread by id that already exists");
// If this is the first thread, save it as the current thread
if (m_threads.empty())
SetCurrentThreadID(thread_id);
m_threads.push_back(std::make_unique<NativeThreadFreeBSD>(*this, thread_id));
return static_cast<NativeThreadFreeBSD &>(*m_threads.back());
}
void NativeProcessFreeBSD::RemoveThread(lldb::tid_t thread_id) {
Log *log = GetLog(POSIXLog::Thread);
LLDB_LOG(log, "pid {0} removing thread with tid {1}", GetID(), thread_id);
assert(thread_id > 0);
assert(HasThreadNoLock(thread_id) &&
"attempted to remove a thread that does not exist");
for (auto it = m_threads.begin(); it != m_threads.end(); ++it) {
if ((*it)->GetID() == thread_id) {
m_threads.erase(it);
break;
}
}
if (GetCurrentThreadID() == thread_id)
SetCurrentThreadID(m_threads.front()->GetID());
}
Status NativeProcessFreeBSD::Attach() {
// Attach to the requested process.
// An attach will cause the thread to stop with a SIGSTOP.
Status status = PtraceWrapper(PT_ATTACH, m_pid);
if (status.Fail())
return status;
int wstatus;
// Need to use WALLSIG otherwise we receive an error with errno=ECHLD At this
// point we should have a thread stopped if waitpid succeeds.
if ((wstatus = llvm::sys::RetryAfterSignal(-1, waitpid, m_pid, nullptr, 0)) <
0)
return Status(errno, eErrorTypePOSIX);
// Initialize threads and tracing status
// NB: this needs to be called before we set thread state
status = SetupTrace();
if (status.Fail())
return status;
for (const auto &thread : m_threads)
static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
// Let our process instance know the thread has stopped.
SetCurrentThreadID(m_threads.front()->GetID());
SetState(StateType::eStateStopped, false);
return Status();
}
Status NativeProcessFreeBSD::ReadMemory(lldb::addr_t addr, void *buf,
size_t size, size_t &bytes_read) {
unsigned char *dst = static_cast<unsigned char *>(buf);
struct ptrace_io_desc io;
Log *log = GetLog(POSIXLog::Memory);
LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
bytes_read = 0;
io.piod_op = PIOD_READ_D;
io.piod_len = size;
do {
io.piod_offs = (void *)(addr + bytes_read);
io.piod_addr = dst + bytes_read;
Status error = NativeProcessFreeBSD::PtraceWrapper(PT_IO, GetID(), &io);
if (error.Fail() || io.piod_len == 0)
return error;
bytes_read += io.piod_len;
io.piod_len = size - bytes_read;
} while (bytes_read < size);
return Status();
}
Status NativeProcessFreeBSD::WriteMemory(lldb::addr_t addr, const void *buf,
size_t size, size_t &bytes_written) {
const unsigned char *src = static_cast<const unsigned char *>(buf);
Status error;
struct ptrace_io_desc io;
Log *log = GetLog(POSIXLog::Memory);
LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
bytes_written = 0;
io.piod_op = PIOD_WRITE_D;
io.piod_len = size;
do {
io.piod_addr =
const_cast<void *>(static_cast<const void *>(src + bytes_written));
io.piod_offs = (void *)(addr + bytes_written);
Status error = NativeProcessFreeBSD::PtraceWrapper(PT_IO, GetID(), &io);
if (error.Fail() || io.piod_len == 0)
return error;
bytes_written += io.piod_len;
io.piod_len = size - bytes_written;
} while (bytes_written < size);
return error;
}
llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
NativeProcessFreeBSD::GetAuxvData() const {
int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_AUXV, static_cast<int>(GetID())};
size_t auxv_size = AT_COUNT * sizeof(Elf_Auxinfo);
std::unique_ptr<WritableMemoryBuffer> buf =
llvm::WritableMemoryBuffer::getNewMemBuffer(auxv_size);
if (::sysctl(mib, 4, buf->getBufferStart(), &auxv_size, nullptr, 0) != 0)
return std::error_code(errno, std::generic_category());
return buf;
}
Status NativeProcessFreeBSD::SetupTrace() {
// Enable event reporting
int events;
Status status =
PtraceWrapper(PT_GET_EVENT_MASK, GetID(), &events, sizeof(events));
if (status.Fail())
return status;
events |= PTRACE_LWP | PTRACE_FORK | PTRACE_VFORK;
status = PtraceWrapper(PT_SET_EVENT_MASK, GetID(), &events, sizeof(events));
if (status.Fail())
return status;
return ReinitializeThreads();
}
Status NativeProcessFreeBSD::ReinitializeThreads() {
// Clear old threads
m_threads.clear();
int num_lwps;
Status error = PtraceWrapper(PT_GETNUMLWPS, GetID(), nullptr, 0, &num_lwps);
if (error.Fail())
return error;
std::vector<lwpid_t> lwp_ids;
lwp_ids.resize(num_lwps);
error = PtraceWrapper(PT_GETLWPLIST, GetID(), lwp_ids.data(),
lwp_ids.size() * sizeof(lwpid_t), &num_lwps);
if (error.Fail())
return error;
// Reinitialize from scratch threads and register them in process
for (lwpid_t lwp : lwp_ids)
AddThread(lwp);
return error;
}
bool NativeProcessFreeBSD::SupportHardwareSingleStepping() const {
return !m_arch.IsMIPS();
}
void NativeProcessFreeBSD::MonitorClone(::pid_t child_pid, bool is_vfork,
NativeThreadFreeBSD &parent_thread) {
Log *log = GetLog(POSIXLog::Process);
LLDB_LOG(log, "fork, child_pid={0}", child_pid);
int status;
::pid_t wait_pid =
llvm::sys::RetryAfterSignal(-1, ::waitpid, child_pid, &status, 0);
if (wait_pid != child_pid) {
LLDB_LOG(log,
"waiting for pid {0} failed. Assuming the pid has "
"disappeared in the meantime",
child_pid);
return;
}
if (WIFEXITED(status)) {
LLDB_LOG(log,
"waiting for pid {0} returned an 'exited' event. Not "
"tracking it.",
child_pid);
return;
}
struct ptrace_lwpinfo info;
const auto siginfo_err = PtraceWrapper(PT_LWPINFO, child_pid, &info, sizeof(info));
if (siginfo_err.Fail()) {
LLDB_LOG(log, "PT_LWPINFO failed {0}", siginfo_err);
return;
}
assert(info.pl_event == PL_EVENT_SIGNAL);
lldb::tid_t child_tid = info.pl_lwpid;
std::unique_ptr<NativeProcessFreeBSD> child_process{
new NativeProcessFreeBSD(static_cast<::pid_t>(child_pid), m_terminal_fd,
m_delegate, m_arch, m_main_loop)};
if (!is_vfork)
child_process->m_software_breakpoints = m_software_breakpoints;
Extension expected_ext = is_vfork ? Extension::vfork : Extension::fork;
if ((m_enabled_extensions & expected_ext) == expected_ext) {
child_process->SetupTrace();
for (const auto &thread : child_process->m_threads)
static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
child_process->SetState(StateType::eStateStopped, false);
m_delegate.NewSubprocess(this, std::move(child_process));
if (is_vfork)
parent_thread.SetStoppedByVFork(child_pid, child_tid);
else
parent_thread.SetStoppedByFork(child_pid, child_tid);
SetState(StateType::eStateStopped, true);
} else {
child_process->Detach();
Status pt_error =
PtraceWrapper(PT_CONTINUE, GetID(), reinterpret_cast<void *>(1), 0);
if (pt_error.Fail()) {
LLDB_LOG_ERROR(log, pt_error.ToError(),
"unable to resume parent process {1}: {0}", GetID());
SetState(StateType::eStateInvalid);
}
}
}
llvm::Expected<std::string>
NativeProcessFreeBSD::SaveCore(llvm::StringRef path_hint) {
#if defined(PT_COREDUMP)
using namespace llvm::sys::fs;
llvm::SmallString<128> path{path_hint};
Status error;
struct ptrace_coredump pc = {};
// Try with the suggested path first. If there is no suggested path or it
// failed to open, use a temporary file.
if (path.empty() ||
openFile(path, pc.pc_fd, CD_CreateNew, FA_Write, OF_None)) {
if (std::error_code errc =
createTemporaryFile("lldb", "core", pc.pc_fd, path))
return llvm::createStringError(errc, "Unable to create a temporary file");
}
error = PtraceWrapper(PT_COREDUMP, GetID(), &pc, sizeof(pc));
std::error_code close_err = closeFile(pc.pc_fd);
if (error.Fail())
return error.ToError();
if (close_err)
return llvm::createStringError(
close_err, "Unable to close the core dump after writing");
return path.str().str();
#else // !defined(PT_COREDUMP)
return llvm::createStringError(
llvm::inconvertibleErrorCode(),
"PT_COREDUMP not supported in the FreeBSD version used to build LLDB");
#endif
}
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