1//===-- NativeProcessFreeBSD.cpp ------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "NativeProcessFreeBSD.h"
10
11// clang-format off
12#include <sys/types.h>
13#include <sys/ptrace.h>
14#include <sys/sysctl.h>
15#include <sys/user.h>
16#include <sys/wait.h>
17#include <machine/elf.h>
18// clang-format on
19
20#include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
21#include "lldb/Host/HostProcess.h"
22#include "lldb/Host/posix/ProcessLauncherPosixFork.h"
23#include "lldb/Target/Process.h"
24#include "lldb/Utility/State.h"
25#include "llvm/Support/Errno.h"
26
27using namespace lldb;
28using namespace lldb_private;
29using namespace lldb_private::process_freebsd;
30using namespace llvm;
31
32// Simple helper function to ensure flags are enabled on the given file
33// descriptor.
34static Status EnsureFDFlags(int fd, int flags) {
35 Status error;
36
37 int status = fcntl(fd: fd, F_GETFL);
38 if (status == -1) {
39 error = Status::FromErrno();
40 return error;
41 }
42
43 if (fcntl(fd: fd, F_SETFL, status | flags) == -1) {
44 error = Status::FromErrno();
45 return error;
46 }
47
48 return error;
49}
50
51static Status CanTrace() {
52 int proc_debug, ret;
53 size_t len = sizeof(proc_debug);
54 ret = ::sysctlbyname("security.bsd.unprivileged_proc_debug", &proc_debug,
55 &len, nullptr, 0);
56 if (ret != 0)
57 return Status::FromErrorString(
58 str: "sysctlbyname() security.bsd.unprivileged_proc_debug failed");
59
60 if (proc_debug < 1)
61 return Status::FromErrorString(
62 str: "process debug disabled by security.bsd.unprivileged_proc_debug oid");
63
64 return {};
65}
66
67// Public Static Methods
68
69llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
70NativeProcessFreeBSD::Manager::Launch(ProcessLaunchInfo &launch_info,
71 NativeDelegate &native_delegate) {
72 Log *log = GetLog(mask: POSIXLog::Process);
73 Status status;
74
75 ::pid_t pid = ProcessLauncherPosixFork()
76 .LaunchProcess(launch_info, error&: status)
77 .GetProcessId();
78 LLDB_LOG(log, "pid = {0:x}", pid);
79 if (status.Fail()) {
80 LLDB_LOG(log, "failed to launch process: {0}", status);
81 auto error = CanTrace();
82 if (error.Fail())
83 return error.ToError();
84 return status.ToError();
85 }
86
87 // Wait for the child process to trap on its call to execve.
88 int wstatus;
89 ::pid_t wpid = llvm::sys::RetryAfterSignal(Fail: -1, F&: ::waitpid, As: pid, As: &wstatus, As: 0);
90 assert(wpid == pid);
91 UNUSED_IF_ASSERT_DISABLED(wpid);
92 if (!WIFSTOPPED(wstatus)) {
93 LLDB_LOG(log, "Could not sync with inferior process: wstatus={1}",
94 WaitStatus::Decode(wstatus));
95 return llvm::make_error<StringError>(Args: "Could not sync with inferior process",
96 Args: llvm::inconvertibleErrorCode());
97 }
98 LLDB_LOG(log, "inferior started, now in stopped state");
99
100 ProcessInstanceInfo Info;
101 if (!Host::GetProcessInfo(pid, proc_info&: Info)) {
102 return llvm::make_error<StringError>(Args: "Cannot get process architecture",
103 Args: llvm::inconvertibleErrorCode());
104 }
105
106 // Set the architecture to the exe architecture.
107 LLDB_LOG(log, "pid = {0:x}, detected architecture {1}", pid,
108 Info.GetArchitecture().GetArchitectureName());
109
110 std::unique_ptr<NativeProcessFreeBSD> process_up(new NativeProcessFreeBSD(
111 pid, launch_info.GetPTY().ReleasePrimaryFileDescriptor(), native_delegate,
112 Info.GetArchitecture(), m_mainloop));
113
114 status = process_up->SetupTrace();
115 if (status.Fail())
116 return status.ToError();
117
118 for (const auto &thread : process_up->m_threads)
119 static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
120 process_up->SetState(state: StateType::eStateStopped, notify_delegates: false);
121
122 return std::move(process_up);
123}
124
125llvm::Expected<std::unique_ptr<NativeProcessProtocol>>
126NativeProcessFreeBSD::Manager::Attach(
127 lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &native_delegate) {
128 Log *log = GetLog(mask: POSIXLog::Process);
129 LLDB_LOG(log, "pid = {0:x}", pid);
130
131 // Retrieve the architecture for the running process.
132 ProcessInstanceInfo Info;
133 if (!Host::GetProcessInfo(pid, proc_info&: Info)) {
134 return llvm::make_error<StringError>(Args: "Cannot get process architecture",
135 Args: llvm::inconvertibleErrorCode());
136 }
137
138 std::unique_ptr<NativeProcessFreeBSD> process_up(new NativeProcessFreeBSD(
139 pid, -1, native_delegate, Info.GetArchitecture(), m_mainloop));
140
141 Status status = process_up->Attach();
142 if (!status.Success())
143 return status.ToError();
144
145 return std::move(process_up);
146}
147
148NativeProcessFreeBSD::Extension
149NativeProcessFreeBSD::Manager::GetSupportedExtensions() const {
150 return
151#if defined(PT_COREDUMP)
152 Extension::savecore |
153#endif
154 Extension::multiprocess | Extension::fork | Extension::vfork |
155 Extension::pass_signals | Extension::auxv | Extension::libraries_svr4 |
156 Extension::siginfo_read;
157}
158
159// Public Instance Methods
160
161NativeProcessFreeBSD::NativeProcessFreeBSD(::pid_t pid, int terminal_fd,
162 NativeDelegate &delegate,
163 const ArchSpec &arch,
164 MainLoop &mainloop)
165 : NativeProcessELF(pid, terminal_fd, delegate), m_arch(arch),
166 m_main_loop(mainloop) {
167 if (m_terminal_fd != -1) {
168 Status status = EnsureFDFlags(fd: m_terminal_fd, O_NONBLOCK);
169 assert(status.Success());
170 }
171
172 Status status;
173 m_sigchld_handle = mainloop.RegisterSignal(
174 SIGCHLD, callback: [this](MainLoopBase &) { SigchldHandler(); }, error&: status);
175 assert(m_sigchld_handle && status.Success());
176}
177
178// Handles all waitpid events from the inferior process.
179void NativeProcessFreeBSD::MonitorCallback(lldb::pid_t pid, int signal) {
180 switch (signal) {
181 case SIGTRAP:
182 return MonitorSIGTRAP(pid);
183 case SIGSTOP:
184 return MonitorSIGSTOP(pid);
185 default:
186 return MonitorSignal(pid, signal);
187 }
188}
189
190void NativeProcessFreeBSD::MonitorExited(lldb::pid_t pid, WaitStatus status) {
191 Log *log = GetLog(mask: POSIXLog::Process);
192
193 LLDB_LOG(log, "got exit signal({0}) , pid = {1}", status, pid);
194
195 /* Stop Tracking All Threads attached to Process */
196 m_threads.clear();
197
198 SetExitStatus(status, bNotifyStateChange: true);
199
200 // Notify delegate that our process has exited.
201 SetState(state: StateType::eStateExited, notify_delegates: true);
202}
203
204void NativeProcessFreeBSD::MonitorSIGSTOP(lldb::pid_t pid) {
205 /* Stop all Threads attached to Process */
206 for (const auto &thread : m_threads) {
207 static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP,
208 info: nullptr);
209 }
210 SetState(state: StateType::eStateStopped, notify_delegates: true);
211}
212
213void NativeProcessFreeBSD::MonitorSIGTRAP(lldb::pid_t pid) {
214 Log *log = GetLog(mask: POSIXLog::Process);
215 struct ptrace_lwpinfo info;
216
217 const auto siginfo_err = PtraceWrapper(PT_LWPINFO, pid, &info, sizeof(info));
218 if (siginfo_err.Fail()) {
219 LLDB_LOG(log, "PT_LWPINFO failed {0}", siginfo_err);
220 return;
221 }
222 assert(info.pl_event == PL_EVENT_SIGNAL);
223
224 LLDB_LOG(log, "got SIGTRAP, pid = {0}, lwpid = {1}, flags = {2:x}", pid,
225 info.pl_lwpid, info.pl_flags);
226 NativeThreadFreeBSD *thread = nullptr;
227
228 if (info.pl_flags & (PL_FLAG_BORN | PL_FLAG_EXITED)) {
229 if (info.pl_flags & PL_FLAG_BORN) {
230 LLDB_LOG(log, "monitoring new thread, tid = {0}", info.pl_lwpid);
231 NativeThreadFreeBSD &t = AddThread(thread_id: info.pl_lwpid);
232
233 // Technically, the FreeBSD kernel copies the debug registers to new
234 // threads. However, there is a non-negligible delay between acquiring
235 // the DR values and reporting the new thread during which the user may
236 // establish a new watchpoint. In order to ensure that watchpoints
237 // established during this period are propagated to new threads,
238 // explicitly copy the DR value at the time the new thread is reported.
239 //
240 // See also: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=250954
241
242 llvm::Error error = t.CopyWatchpointsFrom(
243 source&: static_cast<NativeThreadFreeBSD &>(*GetCurrentThread()));
244 if (error) {
245 LLDB_LOG_ERROR(log, std::move(error),
246 "failed to copy watchpoints to new thread {1}: {0}",
247 info.pl_lwpid);
248 SetState(state: StateType::eStateInvalid);
249 return;
250 }
251 } else /*if (info.pl_flags & PL_FLAG_EXITED)*/ {
252 LLDB_LOG(log, "thread exited, tid = {0}", info.pl_lwpid);
253 RemoveThread(thread_id: info.pl_lwpid);
254 }
255
256 Status error =
257 PtraceWrapper(PT_CONTINUE, pid, addr: reinterpret_cast<void *>(1), data: 0);
258 if (error.Fail())
259 SetState(state: StateType::eStateInvalid);
260 return;
261 }
262
263 if (info.pl_flags & PL_FLAG_EXEC) {
264 Status error = ReinitializeThreads();
265 if (error.Fail()) {
266 SetState(state: StateType::eStateInvalid);
267 return;
268 }
269
270 // Let our delegate know we have just exec'd.
271 NotifyDidExec();
272
273 for (const auto &thread : m_threads)
274 static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedByExec();
275 SetCurrentThreadID(m_threads.front()->GetID());
276 SetState(state: StateType::eStateStopped, notify_delegates: true);
277 return;
278 }
279
280 if (info.pl_lwpid > 0) {
281 for (const auto &t : m_threads) {
282 if (t->GetID() == static_cast<lldb::tid_t>(info.pl_lwpid))
283 thread = static_cast<NativeThreadFreeBSD *>(t.get());
284 static_cast<NativeThreadFreeBSD *>(t.get())->SetStoppedWithNoReason();
285 }
286 if (!thread)
287 LLDB_LOG(log, "thread not found in m_threads, pid = {0}, LWP = {1}", pid,
288 info.pl_lwpid);
289 }
290
291 if (info.pl_flags & PL_FLAG_FORKED) {
292 assert(thread);
293 MonitorClone(child_pid: info.pl_child_pid, is_vfork: info.pl_flags & PL_FLAG_VFORKED, parent_thread&: *thread);
294 return;
295 }
296
297 if (info.pl_flags & PL_FLAG_VFORK_DONE) {
298 assert(thread);
299 if ((m_enabled_extensions & Extension::vfork) == Extension::vfork) {
300 thread->SetStoppedByVForkDone();
301 SetState(state: StateType::eStateStopped, notify_delegates: true);
302 } else {
303 Status error =
304 PtraceWrapper(PT_CONTINUE, pid, addr: reinterpret_cast<void *>(1), data: 0);
305 if (error.Fail())
306 SetState(state: StateType::eStateInvalid);
307 }
308 return;
309 }
310
311 if (info.pl_flags & PL_FLAG_SI) {
312 assert(info.pl_siginfo.si_signo == SIGTRAP);
313 LLDB_LOG(log, "SIGTRAP siginfo: si_code = {0}, pid = {1}",
314 info.pl_siginfo.si_code, info.pl_siginfo.si_pid);
315
316 switch (info.pl_siginfo.si_code) {
317 case TRAP_BRKPT:
318 LLDB_LOG(log, "SIGTRAP/TRAP_BRKPT: si_addr: {0}",
319 info.pl_siginfo.si_addr);
320
321 if (thread) {
322 auto &regctx = static_cast<NativeRegisterContextFreeBSD &>(
323 thread->GetRegisterContext());
324 auto thread_info =
325 m_threads_stepping_with_breakpoint.find(x: thread->GetID());
326 if (thread_info != m_threads_stepping_with_breakpoint.end() &&
327 thread_info->second == regctx.GetPC()) {
328 thread->SetStoppedByTrace();
329 Status brkpt_error = RemoveBreakpoint(addr: thread_info->second);
330 if (brkpt_error.Fail())
331 LLDB_LOG(log, "pid = {0} remove stepping breakpoint: {1}",
332 thread_info->first, brkpt_error);
333 m_threads_stepping_with_breakpoint.erase(position: thread_info);
334 } else
335 thread->SetStoppedByBreakpoint();
336 FixupBreakpointPCAsNeeded(thread&: *thread);
337 SetCurrentThreadID(thread->GetID());
338 }
339 SetState(state: StateType::eStateStopped, notify_delegates: true);
340 return;
341 case TRAP_TRACE:
342 LLDB_LOG(log, "SIGTRAP/TRAP_TRACE: si_addr: {0}",
343 info.pl_siginfo.si_addr);
344
345 if (thread) {
346 auto &regctx = static_cast<NativeRegisterContextFreeBSD &>(
347 thread->GetRegisterContext());
348 uint32_t wp_index = LLDB_INVALID_INDEX32;
349 Status error = regctx.GetWatchpointHitIndex(
350 wp_index, trap_addr: reinterpret_cast<uintptr_t>(info.pl_siginfo.si_addr));
351 if (error.Fail())
352 LLDB_LOG(log,
353 "received error while checking for watchpoint hits, pid = "
354 "{0}, LWP = {1}, error = {2}",
355 pid, info.pl_lwpid, error);
356 if (wp_index != LLDB_INVALID_INDEX32) {
357 regctx.ClearWatchpointHit(hw_index: wp_index);
358 thread->SetStoppedByWatchpoint(wp_index);
359 SetCurrentThreadID(thread->GetID());
360 SetState(state: StateType::eStateStopped, notify_delegates: true);
361 break;
362 }
363
364 thread->SetStoppedByTrace();
365 SetCurrentThreadID(thread->GetID());
366 }
367
368 SetState(state: StateType::eStateStopped, notify_delegates: true);
369 return;
370 }
371 }
372
373 // Either user-generated SIGTRAP or an unknown event that would
374 // otherwise leave the debugger hanging.
375 LLDB_LOG(log, "unknown SIGTRAP, passing to generic handler");
376 MonitorSignal(pid, SIGTRAP);
377}
378
379void NativeProcessFreeBSD::MonitorSignal(lldb::pid_t pid, int signal) {
380 Log *log = GetLog(mask: POSIXLog::Process);
381 struct ptrace_lwpinfo info;
382
383 const auto siginfo_err = PtraceWrapper(PT_LWPINFO, pid, &info, sizeof(info));
384 if (siginfo_err.Fail()) {
385 LLDB_LOG(log, "PT_LWPINFO failed {0}", siginfo_err);
386 return;
387 }
388 assert(info.pl_event == PL_EVENT_SIGNAL);
389 // TODO: do we need to handle !PL_FLAG_SI?
390 assert(info.pl_flags & PL_FLAG_SI);
391 assert(info.pl_siginfo.si_signo == signal);
392
393 for (const auto &abs_thread : m_threads) {
394 NativeThreadFreeBSD &thread =
395 static_cast<NativeThreadFreeBSD &>(*abs_thread);
396 assert(info.pl_lwpid >= 0);
397 if (info.pl_lwpid == 0 ||
398 static_cast<lldb::tid_t>(info.pl_lwpid) == thread.GetID()) {
399 thread.SetStoppedBySignal(signo: info.pl_siginfo.si_signo, info: &info.pl_siginfo);
400 SetCurrentThreadID(thread.GetID());
401 } else
402 thread.SetStoppedWithNoReason();
403 }
404 SetState(state: StateType::eStateStopped, notify_delegates: true);
405}
406
407Status NativeProcessFreeBSD::PtraceWrapper(int req, lldb::pid_t pid, void *addr,
408 int data, int *result) {
409 Log *log = GetLog(mask: POSIXLog::Ptrace);
410 Status error;
411 int ret;
412
413 errno = 0;
414 ret =
415 ptrace(req, static_cast<::pid_t>(pid), static_cast<caddr_t>(addr), data);
416
417 if (ret == -1) {
418 error = CanTrace();
419 if (error.Success())
420 error = Status::FromErrno();
421 }
422
423 if (result)
424 *result = ret;
425
426 LLDB_LOG(log, "ptrace({0}, {1}, {2}, {3})={4:x}", req, pid, addr, data, ret);
427
428 if (error.Fail())
429 LLDB_LOG(log, "ptrace() failed: {0}", error);
430
431 return error;
432}
433
434llvm::Expected<llvm::ArrayRef<uint8_t>>
435NativeProcessFreeBSD::GetSoftwareBreakpointTrapOpcode(size_t size_hint) {
436 static const uint8_t g_arm_opcode[] = {0xfe, 0xde, 0xff, 0xe7};
437 static const uint8_t g_thumb_opcode[] = {0x01, 0xde};
438
439 switch (GetArchitecture().GetMachine()) {
440 case llvm::Triple::arm:
441 switch (size_hint) {
442 case 2:
443 return llvm::ArrayRef(g_thumb_opcode);
444 case 4:
445 return llvm::ArrayRef(g_arm_opcode);
446 default:
447 return llvm::createStringError(EC: llvm::inconvertibleErrorCode(),
448 S: "Unrecognised trap opcode size hint!");
449 }
450 default:
451 return NativeProcessProtocol::GetSoftwareBreakpointTrapOpcode(size_hint);
452 }
453}
454
455Status NativeProcessFreeBSD::Resume(const ResumeActionList &resume_actions) {
456 Log *log = GetLog(mask: POSIXLog::Process);
457 LLDB_LOG(log, "pid {0}", GetID());
458
459 Status ret;
460
461 int signal = 0;
462 for (const auto &abs_thread : m_threads) {
463 assert(abs_thread && "thread list should not contain NULL threads");
464 NativeThreadFreeBSD &thread =
465 static_cast<NativeThreadFreeBSD &>(*abs_thread);
466
467 const ResumeAction *action =
468 resume_actions.GetActionForThread(tid: thread.GetID(), default_ok: true);
469 // we need to explicit issue suspend requests, so it is simpler to map it
470 // into proper action
471 ResumeAction suspend_action{.tid: thread.GetID(), .state: eStateSuspended,
472 LLDB_INVALID_SIGNAL_NUMBER};
473
474 if (action == nullptr) {
475 LLDB_LOG(log, "no action specified for pid {0} tid {1}", GetID(),
476 thread.GetID());
477 action = &suspend_action;
478 }
479
480 LLDB_LOG(
481 log,
482 "processing resume action state {0} signal {1} for pid {2} tid {3}",
483 action->state, action->signal, GetID(), thread.GetID());
484
485 switch (action->state) {
486 case eStateRunning:
487 ret = thread.Resume();
488 break;
489 case eStateStepping:
490 ret = thread.SingleStep();
491 break;
492 case eStateSuspended:
493 case eStateStopped:
494 if (action->signal != LLDB_INVALID_SIGNAL_NUMBER)
495 return Status::FromErrorString(
496 str: "Passing signal to suspended thread unsupported");
497
498 ret = thread.Suspend();
499 break;
500
501 default:
502 return Status::FromErrorStringWithFormat(
503 format: "NativeProcessFreeBSD::%s (): unexpected state %s specified "
504 "for pid %" PRIu64 ", tid %" PRIu64,
505 __FUNCTION__, StateAsCString(state: action->state), GetID(), thread.GetID());
506 }
507
508 if (!ret.Success())
509 return ret;
510 if (action->signal != LLDB_INVALID_SIGNAL_NUMBER)
511 signal = action->signal;
512 }
513
514 ret =
515 PtraceWrapper(PT_CONTINUE, pid: GetID(), addr: reinterpret_cast<void *>(1), data: signal);
516 if (ret.Success())
517 SetState(state: eStateRunning, notify_delegates: true);
518 return ret;
519}
520
521Status NativeProcessFreeBSD::Halt() {
522 Status error;
523
524 // Do not try to stop a process that's already stopped, this may cause
525 // the SIGSTOP to get queued and stop the process again once resumed.
526 if (StateIsStoppedState(state: m_state, must_exist: false))
527 return error;
528 if (kill(pid: GetID(), SIGSTOP) != 0)
529 error = Status::FromErrno();
530 return error;
531}
532
533Status NativeProcessFreeBSD::Detach() {
534 Status error;
535
536 // Stop monitoring the inferior.
537 m_sigchld_handle.reset();
538
539 // Tell ptrace to detach from the process.
540 if (GetID() == LLDB_INVALID_PROCESS_ID)
541 return error;
542
543 return PtraceWrapper(PT_DETACH, pid: GetID());
544}
545
546Status NativeProcessFreeBSD::Signal(int signo) {
547 Status error;
548
549 if (kill(pid: GetID(), sig: signo))
550 error = Status::FromErrno();
551
552 return error;
553}
554
555Status NativeProcessFreeBSD::Interrupt() { return Halt(); }
556
557Status NativeProcessFreeBSD::Kill() {
558 Log *log = GetLog(mask: POSIXLog::Process);
559 LLDB_LOG(log, "pid {0}", GetID());
560
561 Status error;
562
563 switch (m_state) {
564 case StateType::eStateInvalid:
565 case StateType::eStateExited:
566 case StateType::eStateCrashed:
567 case StateType::eStateDetached:
568 case StateType::eStateUnloaded:
569 // Nothing to do - the process is already dead.
570 LLDB_LOG(log, "ignored for PID {0} due to current state: {1}", GetID(),
571 StateAsCString(m_state));
572 return error;
573
574 case StateType::eStateConnected:
575 case StateType::eStateAttaching:
576 case StateType::eStateLaunching:
577 case StateType::eStateStopped:
578 case StateType::eStateRunning:
579 case StateType::eStateStepping:
580 case StateType::eStateSuspended:
581 // We can try to kill a process in these states.
582 break;
583 }
584
585 return PtraceWrapper(PT_KILL, pid: m_pid);
586}
587
588Status NativeProcessFreeBSD::GetMemoryRegionInfo(lldb::addr_t load_addr,
589 MemoryRegionInfo &range_info) {
590
591 if (m_supports_mem_region == LazyBool::eLazyBoolNo) {
592 // We're done.
593 return Status::FromErrorString(str: "unsupported");
594 }
595
596 Status error = PopulateMemoryRegionCache();
597 if (error.Fail()) {
598 return error;
599 }
600
601 lldb::addr_t prev_base_address = 0;
602 // FIXME start by finding the last region that is <= target address using
603 // binary search. Data is sorted.
604 // There can be a ton of regions on pthreads apps with lots of threads.
605 for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end();
606 ++it) {
607 MemoryRegionInfo &proc_entry_info = it->first;
608 // Sanity check assumption that memory map entries are ascending.
609 assert((proc_entry_info.GetRange().GetRangeBase() >= prev_base_address) &&
610 "descending memory map entries detected, unexpected");
611 prev_base_address = proc_entry_info.GetRange().GetRangeBase();
612 UNUSED_IF_ASSERT_DISABLED(prev_base_address);
613 // If the target address comes before this entry, indicate distance to next
614 // region.
615 if (load_addr < proc_entry_info.GetRange().GetRangeBase()) {
616 range_info.GetRange().SetRangeBase(load_addr);
617 range_info.GetRange().SetByteSize(
618 proc_entry_info.GetRange().GetRangeBase() - load_addr);
619 range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
620 range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
621 range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
622 range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo);
623 return error;
624 } else if (proc_entry_info.GetRange().Contains(r: load_addr)) {
625 // The target address is within the memory region we're processing here.
626 range_info = proc_entry_info;
627 return error;
628 }
629 // The target memory address comes somewhere after the region we just
630 // parsed.
631 }
632 // If we made it here, we didn't find an entry that contained the given
633 // address. Return the load_addr as start and the amount of bytes betwwen
634 // load address and the end of the memory as size.
635 range_info.GetRange().SetRangeBase(load_addr);
636 range_info.GetRange().SetRangeEnd(LLDB_INVALID_ADDRESS);
637 range_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
638 range_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
639 range_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
640 range_info.SetMapped(MemoryRegionInfo::OptionalBool::eNo);
641 return error;
642}
643
644Status NativeProcessFreeBSD::PopulateMemoryRegionCache() {
645 Log *log = GetLog(mask: POSIXLog::Process);
646 // If our cache is empty, pull the latest. There should always be at least
647 // one memory region if memory region handling is supported.
648 if (!m_mem_region_cache.empty()) {
649 LLDB_LOG(log, "reusing {0} cached memory region entries",
650 m_mem_region_cache.size());
651 return Status();
652 }
653
654 int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, static_cast<int>(m_pid)};
655 int ret;
656 size_t len;
657
658 ret = ::sysctl(mib, 4, nullptr, &len, nullptr, 0);
659 if (ret != 0) {
660 m_supports_mem_region = LazyBool::eLazyBoolNo;
661 return Status::FromErrorString(str: "sysctl() for KERN_PROC_VMMAP failed");
662 }
663
664 std::unique_ptr<WritableMemoryBuffer> buf =
665 llvm::WritableMemoryBuffer::getNewMemBuffer(Size: len);
666 ret = ::sysctl(mib, 4, buf->getBufferStart(), &len, nullptr, 0);
667 if (ret != 0) {
668 m_supports_mem_region = LazyBool::eLazyBoolNo;
669 return Status::FromErrorString(str: "sysctl() for KERN_PROC_VMMAP failed");
670 }
671
672 char *bp = buf->getBufferStart();
673 char *end = bp + len;
674 while (bp < end) {
675 auto *kv = reinterpret_cast<struct kinfo_vmentry *>(bp);
676 if (kv->kve_structsize == 0)
677 break;
678 bp += kv->kve_structsize;
679
680 MemoryRegionInfo info;
681 info.Clear();
682 info.GetRange().SetRangeBase(kv->kve_start);
683 info.GetRange().SetRangeEnd(kv->kve_end);
684 info.SetMapped(MemoryRegionInfo::OptionalBool::eYes);
685
686 if (kv->kve_protection & VM_PROT_READ)
687 info.SetReadable(MemoryRegionInfo::OptionalBool::eYes);
688 else
689 info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
690
691 if (kv->kve_protection & VM_PROT_WRITE)
692 info.SetWritable(MemoryRegionInfo::OptionalBool::eYes);
693 else
694 info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
695
696 if (kv->kve_protection & VM_PROT_EXECUTE)
697 info.SetExecutable(MemoryRegionInfo::OptionalBool::eYes);
698 else
699 info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
700
701 if (kv->kve_path[0])
702 info.SetName(kv->kve_path);
703
704 m_mem_region_cache.emplace_back(args&: info,
705 args: FileSpec(info.GetName().GetCString()));
706 }
707
708 if (m_mem_region_cache.empty()) {
709 // No entries after attempting to read them. This shouldn't happen. Assume
710 // we don't support map entries.
711 LLDB_LOG(log, "failed to find any vmmap entries, assuming no support "
712 "for memory region metadata retrieval");
713 m_supports_mem_region = LazyBool::eLazyBoolNo;
714 return Status::FromErrorString(str: "not supported");
715 }
716 LLDB_LOG(log, "read {0} memory region entries from process {1}",
717 m_mem_region_cache.size(), GetID());
718 // We support memory retrieval, remember that.
719 m_supports_mem_region = LazyBool::eLazyBoolYes;
720
721 return Status();
722}
723
724size_t NativeProcessFreeBSD::UpdateThreads() { return m_threads.size(); }
725
726Status NativeProcessFreeBSD::SetBreakpoint(lldb::addr_t addr, uint32_t size,
727 bool hardware) {
728 if (hardware)
729 return SetHardwareBreakpoint(addr, size);
730 return SetSoftwareBreakpoint(addr, size_hint: size);
731}
732
733Status NativeProcessFreeBSD::GetLoadedModuleFileSpec(const char *module_path,
734 FileSpec &file_spec) {
735 Status error = PopulateMemoryRegionCache();
736 if (error.Fail()) {
737 auto status = CanTrace();
738 if (status.Fail())
739 return status;
740 return error;
741 }
742
743 FileSpec module_file_spec(module_path);
744 FileSystem::Instance().Resolve(file_spec&: module_file_spec);
745
746 file_spec.Clear();
747 for (const auto &it : m_mem_region_cache) {
748 if (it.second.GetFilename() == module_file_spec.GetFilename()) {
749 file_spec = it.second;
750 return Status();
751 }
752 }
753 return Status::FromErrorStringWithFormat(
754 format: "Module file (%s) not found in process' memory map!",
755 module_file_spec.GetFilename().AsCString());
756}
757
758Status
759NativeProcessFreeBSD::GetFileLoadAddress(const llvm::StringRef &file_name,
760 lldb::addr_t &load_addr) {
761 load_addr = LLDB_INVALID_ADDRESS;
762 Status error = PopulateMemoryRegionCache();
763 if (error.Fail()) {
764 auto status = CanTrace();
765 if (status.Fail())
766 return status;
767 return error;
768 }
769
770 FileSpec file(file_name);
771 for (const auto &it : m_mem_region_cache) {
772 if (it.second == file) {
773 load_addr = it.first.GetRange().GetRangeBase();
774 return Status();
775 }
776 }
777 return Status::FromErrorStringWithFormat(format: "No load address found for file %s.",
778 file_name.str().c_str());
779}
780
781void NativeProcessFreeBSD::SigchldHandler() {
782 Log *log = GetLog(mask: POSIXLog::Process);
783 int status;
784 ::pid_t wait_pid =
785 llvm::sys::RetryAfterSignal(Fail: -1, F&: waitpid, As: GetID(), As: &status, WNOHANG);
786
787 if (wait_pid == 0)
788 return;
789
790 if (wait_pid == -1) {
791 Status error(errno, eErrorTypePOSIX);
792 LLDB_LOG(log, "waitpid ({0}, &status, _) failed: {1}", GetID(), error);
793 return;
794 }
795
796 WaitStatus wait_status = WaitStatus::Decode(wstatus: status);
797 bool exited = wait_status.type == WaitStatus::Exit ||
798 (wait_status.type == WaitStatus::Signal &&
799 wait_pid == static_cast<::pid_t>(GetID()));
800
801 LLDB_LOG(log,
802 "waitpid ({0}, &status, _) => pid = {1}, status = {2}, exited = {3}",
803 GetID(), wait_pid, status, exited);
804
805 if (exited)
806 MonitorExited(pid: wait_pid, status: wait_status);
807 else {
808 assert(wait_status.type == WaitStatus::Stop);
809 MonitorCallback(pid: wait_pid, signal: wait_status.status);
810 }
811}
812
813bool NativeProcessFreeBSD::HasThreadNoLock(lldb::tid_t thread_id) {
814 for (const auto &thread : m_threads) {
815 assert(thread && "thread list should not contain NULL threads");
816 if (thread->GetID() == thread_id) {
817 // We have this thread.
818 return true;
819 }
820 }
821
822 // We don't have this thread.
823 return false;
824}
825
826NativeThreadFreeBSD &NativeProcessFreeBSD::AddThread(lldb::tid_t thread_id) {
827 Log *log = GetLog(mask: POSIXLog::Thread);
828 LLDB_LOG(log, "pid {0} adding thread with tid {1}", GetID(), thread_id);
829
830 assert(thread_id > 0);
831 assert(!HasThreadNoLock(thread_id) &&
832 "attempted to add a thread by id that already exists");
833
834 // If this is the first thread, save it as the current thread
835 if (m_threads.empty())
836 SetCurrentThreadID(thread_id);
837
838 m_threads.push_back(x: std::make_unique<NativeThreadFreeBSD>(args&: *this, args&: thread_id));
839 return static_cast<NativeThreadFreeBSD &>(*m_threads.back());
840}
841
842void NativeProcessFreeBSD::RemoveThread(lldb::tid_t thread_id) {
843 Log *log = GetLog(mask: POSIXLog::Thread);
844 LLDB_LOG(log, "pid {0} removing thread with tid {1}", GetID(), thread_id);
845
846 assert(thread_id > 0);
847 assert(HasThreadNoLock(thread_id) &&
848 "attempted to remove a thread that does not exist");
849
850 for (auto it = m_threads.begin(); it != m_threads.end(); ++it) {
851 if ((*it)->GetID() == thread_id) {
852 m_threads.erase(position: it);
853 break;
854 }
855 }
856
857 if (GetCurrentThreadID() == thread_id)
858 SetCurrentThreadID(m_threads.front()->GetID());
859}
860
861Status NativeProcessFreeBSD::Attach() {
862 // Attach to the requested process.
863 // An attach will cause the thread to stop with a SIGSTOP.
864 Status status = PtraceWrapper(PT_ATTACH, pid: m_pid);
865 if (status.Fail())
866 return status;
867
868 int wstatus;
869 // Need to use WALLSIG otherwise we receive an error with errno=ECHLD At this
870 // point we should have a thread stopped if waitpid succeeds.
871 if ((wstatus = llvm::sys::RetryAfterSignal(Fail: -1, F&: waitpid, As: m_pid, As: nullptr, As: 0)) <
872 0)
873 return Status(errno, eErrorTypePOSIX);
874
875 // Initialize threads and tracing status
876 // NB: this needs to be called before we set thread state
877 status = SetupTrace();
878 if (status.Fail())
879 return status;
880
881 for (const auto &thread : m_threads)
882 static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
883
884 // Let our process instance know the thread has stopped.
885 SetCurrentThreadID(m_threads.front()->GetID());
886 SetState(state: StateType::eStateStopped, notify_delegates: false);
887 return Status();
888}
889
890Status NativeProcessFreeBSD::ReadMemory(lldb::addr_t addr, void *buf,
891 size_t size, size_t &bytes_read) {
892 unsigned char *dst = static_cast<unsigned char *>(buf);
893 struct ptrace_io_desc io;
894
895 Log *log = GetLog(mask: POSIXLog::Memory);
896 LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
897
898 bytes_read = 0;
899 io.piod_op = PIOD_READ_D;
900 io.piod_len = size;
901
902 do {
903 io.piod_offs = (void *)(addr + bytes_read);
904 io.piod_addr = dst + bytes_read;
905
906 Status error = NativeProcessFreeBSD::PtraceWrapper(req: PT_IO, pid: GetID(), addr: &io);
907 if (error.Fail() || io.piod_len == 0)
908 return error;
909
910 bytes_read += io.piod_len;
911 io.piod_len = size - bytes_read;
912 } while (bytes_read < size);
913
914 return Status();
915}
916
917Status NativeProcessFreeBSD::WriteMemory(lldb::addr_t addr, const void *buf,
918 size_t size, size_t &bytes_written) {
919 const unsigned char *src = static_cast<const unsigned char *>(buf);
920 Status error;
921 struct ptrace_io_desc io;
922
923 Log *log = GetLog(mask: POSIXLog::Memory);
924 LLDB_LOG(log, "addr = {0}, buf = {1}, size = {2}", addr, buf, size);
925
926 bytes_written = 0;
927 io.piod_op = PIOD_WRITE_D;
928 io.piod_len = size;
929
930 do {
931 io.piod_addr =
932 const_cast<void *>(static_cast<const void *>(src + bytes_written));
933 io.piod_offs = (void *)(addr + bytes_written);
934
935 Status error = NativeProcessFreeBSD::PtraceWrapper(req: PT_IO, pid: GetID(), addr: &io);
936 if (error.Fail() || io.piod_len == 0)
937 return error;
938
939 bytes_written += io.piod_len;
940 io.piod_len = size - bytes_written;
941 } while (bytes_written < size);
942
943 return error;
944}
945
946llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
947NativeProcessFreeBSD::GetAuxvData() const {
948 int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_AUXV, static_cast<int>(GetID())};
949 size_t auxv_size = AT_COUNT * sizeof(Elf_Auxinfo);
950 std::unique_ptr<WritableMemoryBuffer> buf =
951 llvm::WritableMemoryBuffer::getNewMemBuffer(Size: auxv_size);
952
953 if (::sysctl(mib, 4, buf->getBufferStart(), &auxv_size, nullptr, 0) != 0)
954 return std::error_code(errno, std::generic_category());
955
956 return buf;
957}
958
959Status NativeProcessFreeBSD::SetupTrace() {
960 // Enable event reporting
961 int events;
962 Status status =
963 PtraceWrapper(req: PT_GET_EVENT_MASK, pid: GetID(), addr: &events, data: sizeof(events));
964 if (status.Fail())
965 return status;
966 events |= PTRACE_LWP | PTRACE_FORK | PTRACE_VFORK;
967 status = PtraceWrapper(req: PT_SET_EVENT_MASK, pid: GetID(), addr: &events, data: sizeof(events));
968 if (status.Fail())
969 return status;
970
971 return ReinitializeThreads();
972}
973
974Status NativeProcessFreeBSD::ReinitializeThreads() {
975 // Clear old threads
976 m_threads.clear();
977
978 int num_lwps;
979 Status error = PtraceWrapper(req: PT_GETNUMLWPS, pid: GetID(), addr: nullptr, data: 0, result: &num_lwps);
980 if (error.Fail())
981 return error;
982
983 std::vector<lwpid_t> lwp_ids;
984 lwp_ids.resize(new_size: num_lwps);
985 error = PtraceWrapper(req: PT_GETLWPLIST, pid: GetID(), addr: lwp_ids.data(),
986 data: lwp_ids.size() * sizeof(lwpid_t), result: &num_lwps);
987 if (error.Fail())
988 return error;
989
990 // Reinitialize from scratch threads and register them in process
991 for (lwpid_t lwp : lwp_ids)
992 AddThread(thread_id: lwp);
993
994 return error;
995}
996
997bool NativeProcessFreeBSD::SupportHardwareSingleStepping() const {
998 return !m_arch.IsMIPS();
999}
1000
1001void NativeProcessFreeBSD::MonitorClone(::pid_t child_pid, bool is_vfork,
1002 NativeThreadFreeBSD &parent_thread) {
1003 Log *log = GetLog(mask: POSIXLog::Process);
1004 LLDB_LOG(log, "fork, child_pid={0}", child_pid);
1005
1006 int status;
1007 ::pid_t wait_pid =
1008 llvm::sys::RetryAfterSignal(Fail: -1, F&: ::waitpid, As: child_pid, As: &status, As: 0);
1009 if (wait_pid != child_pid) {
1010 LLDB_LOG(log,
1011 "waiting for pid {0} failed. Assuming the pid has "
1012 "disappeared in the meantime",
1013 child_pid);
1014 return;
1015 }
1016 if (WIFEXITED(status)) {
1017 LLDB_LOG(log,
1018 "waiting for pid {0} returned an 'exited' event. Not "
1019 "tracking it.",
1020 child_pid);
1021 return;
1022 }
1023
1024 struct ptrace_lwpinfo info;
1025 const auto siginfo_err = PtraceWrapper(PT_LWPINFO, child_pid, &info, sizeof(info));
1026 if (siginfo_err.Fail()) {
1027 LLDB_LOG(log, "PT_LWPINFO failed {0}", siginfo_err);
1028 return;
1029 }
1030 assert(info.pl_event == PL_EVENT_SIGNAL);
1031 lldb::tid_t child_tid = info.pl_lwpid;
1032
1033 std::unique_ptr<NativeProcessFreeBSD> child_process{
1034 new NativeProcessFreeBSD(static_cast<::pid_t>(child_pid), m_terminal_fd,
1035 m_delegate, m_arch, m_main_loop)};
1036 if (!is_vfork)
1037 child_process->m_software_breakpoints = m_software_breakpoints;
1038
1039 Extension expected_ext = is_vfork ? Extension::vfork : Extension::fork;
1040 if ((m_enabled_extensions & expected_ext) == expected_ext) {
1041 child_process->SetupTrace();
1042 for (const auto &thread : child_process->m_threads)
1043 static_cast<NativeThreadFreeBSD &>(*thread).SetStoppedBySignal(SIGSTOP);
1044 child_process->SetState(state: StateType::eStateStopped, notify_delegates: false);
1045
1046 m_delegate.NewSubprocess(parent_process: this, child_process: std::move(child_process));
1047 if (is_vfork)
1048 parent_thread.SetStoppedByVFork(child_pid, child_tid);
1049 else
1050 parent_thread.SetStoppedByFork(child_pid, child_tid);
1051 SetState(state: StateType::eStateStopped, notify_delegates: true);
1052 } else {
1053 child_process->Detach();
1054 Status pt_error =
1055 PtraceWrapper(PT_CONTINUE, pid: GetID(), addr: reinterpret_cast<void *>(1), data: 0);
1056 if (pt_error.Fail()) {
1057 LLDB_LOG_ERROR(log, pt_error.ToError(),
1058 "unable to resume parent process {1}: {0}", GetID());
1059 SetState(state: StateType::eStateInvalid);
1060 }
1061 }
1062}
1063
1064llvm::Expected<std::string>
1065NativeProcessFreeBSD::SaveCore(llvm::StringRef path_hint) {
1066#if defined(PT_COREDUMP)
1067 using namespace llvm::sys::fs;
1068
1069 llvm::SmallString<128> path{path_hint};
1070 Status error;
1071 struct ptrace_coredump pc = {};
1072
1073 // Try with the suggested path first. If there is no suggested path or it
1074 // failed to open, use a temporary file.
1075 if (path.empty() ||
1076 openFile(path, pc.pc_fd, CD_CreateNew, FA_Write, OF_None)) {
1077 if (std::error_code errc =
1078 createTemporaryFile("lldb", "core", pc.pc_fd, path))
1079 return llvm::createStringError(errc, "Unable to create a temporary file");
1080 }
1081 error = PtraceWrapper(PT_COREDUMP, GetID(), &pc, sizeof(pc));
1082
1083 std::error_code close_err = closeFile(pc.pc_fd);
1084 if (error.Fail())
1085 return error.ToError();
1086 if (close_err)
1087 return llvm::createStringError(
1088 close_err, "Unable to close the core dump after writing");
1089 return path.str().str();
1090#else // !defined(PT_COREDUMP)
1091 return llvm::createStringError(
1092 EC: llvm::inconvertibleErrorCode(),
1093 S: "PT_COREDUMP not supported in the FreeBSD version used to build LLDB");
1094#endif
1095}
1096

source code of lldb/source/Plugins/Process/FreeBSD/NativeProcessFreeBSD.cpp