1//===-- Host.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// C includes
10#include <cerrno>
11#include <climits>
12#include <cstdlib>
13#include <sys/types.h>
14#ifndef _WIN32
15#include <dlfcn.h>
16#include <grp.h>
17#include <netdb.h>
18#include <pwd.h>
19#include <sys/stat.h>
20#include <unistd.h>
21#endif
22
23#if defined(__APPLE__)
24#include <mach-o/dyld.h>
25#include <mach/mach_init.h>
26#include <mach/mach_port.h>
27#endif
28
29#if defined(__linux__) || defined(__FreeBSD__) || \
30 defined(__FreeBSD_kernel__) || defined(__APPLE__) || \
31 defined(__NetBSD__) || defined(__OpenBSD__) || defined(__EMSCRIPTEN__)
32#if !defined(__ANDROID__)
33#include <spawn.h>
34#endif
35#include <sys/syscall.h>
36#include <sys/wait.h>
37#endif
38
39#if defined(__FreeBSD__)
40#include <pthread_np.h>
41#endif
42
43#if defined(__NetBSD__)
44#include <lwp.h>
45#endif
46
47#include <csignal>
48
49#include "lldb/Host/FileAction.h"
50#include "lldb/Host/FileSystem.h"
51#include "lldb/Host/Host.h"
52#include "lldb/Host/HostInfo.h"
53#include "lldb/Host/HostProcess.h"
54#include "lldb/Host/MonitoringProcessLauncher.h"
55#include "lldb/Host/ProcessLaunchInfo.h"
56#include "lldb/Host/ProcessLauncher.h"
57#include "lldb/Host/ThreadLauncher.h"
58#include "lldb/Host/posix/ConnectionFileDescriptorPosix.h"
59#include "lldb/Utility/FileSpec.h"
60#include "lldb/Utility/LLDBLog.h"
61#include "lldb/Utility/Log.h"
62#include "lldb/Utility/Predicate.h"
63#include "lldb/Utility/Status.h"
64#include "lldb/lldb-private-forward.h"
65#include "llvm/ADT/SmallString.h"
66#include "llvm/Support/Errno.h"
67#include "llvm/Support/FileSystem.h"
68
69#if defined(_WIN32)
70#include "lldb/Host/windows/ConnectionGenericFileWindows.h"
71#include "lldb/Host/windows/ProcessLauncherWindows.h"
72#else
73#include "lldb/Host/posix/ProcessLauncherPosixFork.h"
74#endif
75
76#if defined(__APPLE__)
77#ifndef _POSIX_SPAWN_DISABLE_ASLR
78#define _POSIX_SPAWN_DISABLE_ASLR 0x0100
79#endif
80
81extern "C" {
82int __pthread_chdir(const char *path);
83int __pthread_fchdir(int fildes);
84}
85
86#endif
87
88using namespace lldb;
89using namespace lldb_private;
90
91#if !defined(__APPLE__)
92void Host::SystemLog(llvm::StringRef message) { llvm::errs() << message; }
93#endif
94
95#if !defined(__APPLE__) && !defined(_WIN32)
96static thread_result_t
97MonitorChildProcessThreadFunction(::pid_t pid,
98 Host::MonitorChildProcessCallback callback);
99
100llvm::Expected<HostThread> Host::StartMonitoringChildProcess(
101 const Host::MonitorChildProcessCallback &callback, lldb::pid_t pid) {
102 char thread_name[256];
103 ::snprintf(s: thread_name, maxlen: sizeof(thread_name),
104 format: "<lldb.host.wait4(pid=%" PRIu64 ")>", pid);
105 assert(pid <= UINT32_MAX);
106 return ThreadLauncher::LaunchThread(name: thread_name, thread_function: [pid, callback] {
107 return MonitorChildProcessThreadFunction(pid, callback);
108 });
109}
110
111#ifndef __linux__
112// Scoped class that will disable thread canceling when it is constructed, and
113// exception safely restore the previous value it when it goes out of scope.
114class ScopedPThreadCancelDisabler {
115public:
116 ScopedPThreadCancelDisabler() {
117 // Disable the ability for this thread to be cancelled
118 int err = ::pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &m_old_state);
119 if (err != 0)
120 m_old_state = -1;
121 }
122
123 ~ScopedPThreadCancelDisabler() {
124 // Restore the ability for this thread to be cancelled to what it
125 // previously was.
126 if (m_old_state != -1)
127 ::pthread_setcancelstate(m_old_state, 0);
128 }
129
130private:
131 int m_old_state; // Save the old cancelability state.
132};
133#endif // __linux__
134
135#ifdef __linux__
136static thread_local volatile sig_atomic_t g_usr1_called;
137
138static void SigUsr1Handler(int) { g_usr1_called = 1; }
139#endif // __linux__
140
141static bool CheckForMonitorCancellation() {
142#ifdef __linux__
143 if (g_usr1_called) {
144 g_usr1_called = 0;
145 return true;
146 }
147#else
148 ::pthread_testcancel();
149#endif
150 return false;
151}
152
153static thread_result_t
154MonitorChildProcessThreadFunction(::pid_t pid,
155 Host::MonitorChildProcessCallback callback) {
156 Log *log = GetLog(mask: LLDBLog::Process);
157 LLDB_LOG(log, "pid = {0}", pid);
158
159 int status = -1;
160
161#ifdef __linux__
162 // This signal is only used to interrupt the thread from waitpid
163 struct sigaction sigUsr1Action;
164 memset(s: &sigUsr1Action, c: 0, n: sizeof(sigUsr1Action));
165 sigUsr1Action.sa_handler = SigUsr1Handler;
166 ::sigaction(SIGUSR1, act: &sigUsr1Action, oact: nullptr);
167#endif // __linux__
168
169 while (true) {
170 log = GetLog(mask: LLDBLog::Process);
171 LLDB_LOG(log, "::waitpid({0}, &status, 0)...", pid);
172
173 if (CheckForMonitorCancellation())
174 return nullptr;
175
176 const ::pid_t wait_pid = ::waitpid(pid: pid, stat_loc: &status, options: 0);
177
178 LLDB_LOG(log, "::waitpid({0}, &status, 0) => pid = {1}, status = {2:x}", pid,
179 wait_pid, status);
180
181 if (CheckForMonitorCancellation())
182 return nullptr;
183
184 if (wait_pid != -1)
185 break;
186 if (errno != EINTR) {
187 LLDB_LOG(log, "pid = {0}, thread exiting because waitpid failed ({1})...",
188 pid, llvm::sys::StrError());
189 return nullptr;
190 }
191 }
192
193 int signal = 0;
194 int exit_status = 0;
195 if (WIFEXITED(status)) {
196 exit_status = WEXITSTATUS(status);
197 } else if (WIFSIGNALED(status)) {
198 signal = WTERMSIG(status);
199 exit_status = -1;
200 } else {
201 llvm_unreachable("Unknown status");
202 }
203
204 // Scope for pthread_cancel_disabler
205 {
206#ifndef __linux__
207 ScopedPThreadCancelDisabler pthread_cancel_disabler;
208#endif
209
210 if (callback)
211 callback(pid, signal, exit_status);
212 }
213
214 LLDB_LOG(GetLog(LLDBLog::Process), "pid = {0} thread exiting...", pid);
215 return nullptr;
216}
217
218#endif // #if !defined (__APPLE__) && !defined (_WIN32)
219
220lldb::pid_t Host::GetCurrentProcessID() { return ::getpid(); }
221
222#ifndef _WIN32
223
224lldb::thread_t Host::GetCurrentThread() {
225 return lldb::thread_t(pthread_self());
226}
227
228const char *Host::GetSignalAsCString(int signo) {
229 switch (signo) {
230 case SIGHUP:
231 return "SIGHUP"; // 1 hangup
232 case SIGINT:
233 return "SIGINT"; // 2 interrupt
234 case SIGQUIT:
235 return "SIGQUIT"; // 3 quit
236 case SIGILL:
237 return "SIGILL"; // 4 illegal instruction (not reset when caught)
238 case SIGTRAP:
239 return "SIGTRAP"; // 5 trace trap (not reset when caught)
240 case SIGABRT:
241 return "SIGABRT"; // 6 abort()
242#if defined(SIGPOLL)
243#if !defined(SIGIO) || (SIGPOLL != SIGIO)
244 // Under some GNU/Linux, SIGPOLL and SIGIO are the same. Causing the build to
245 // fail with 'multiple define cases with same value'
246 case SIGPOLL:
247 return "SIGPOLL"; // 7 pollable event ([XSR] generated, not supported)
248#endif
249#endif
250#if defined(SIGEMT)
251 case SIGEMT:
252 return "SIGEMT"; // 7 EMT instruction
253#endif
254 case SIGFPE:
255 return "SIGFPE"; // 8 floating point exception
256 case SIGKILL:
257 return "SIGKILL"; // 9 kill (cannot be caught or ignored)
258 case SIGBUS:
259 return "SIGBUS"; // 10 bus error
260 case SIGSEGV:
261 return "SIGSEGV"; // 11 segmentation violation
262 case SIGSYS:
263 return "SIGSYS"; // 12 bad argument to system call
264 case SIGPIPE:
265 return "SIGPIPE"; // 13 write on a pipe with no one to read it
266 case SIGALRM:
267 return "SIGALRM"; // 14 alarm clock
268 case SIGTERM:
269 return "SIGTERM"; // 15 software termination signal from kill
270 case SIGURG:
271 return "SIGURG"; // 16 urgent condition on IO channel
272 case SIGSTOP:
273 return "SIGSTOP"; // 17 sendable stop signal not from tty
274 case SIGTSTP:
275 return "SIGTSTP"; // 18 stop signal from tty
276 case SIGCONT:
277 return "SIGCONT"; // 19 continue a stopped process
278 case SIGCHLD:
279 return "SIGCHLD"; // 20 to parent on child stop or exit
280 case SIGTTIN:
281 return "SIGTTIN"; // 21 to readers pgrp upon background tty read
282 case SIGTTOU:
283 return "SIGTTOU"; // 22 like TTIN for output if (tp->t_local&LTOSTOP)
284#if defined(SIGIO)
285 case SIGIO:
286 return "SIGIO"; // 23 input/output possible signal
287#endif
288 case SIGXCPU:
289 return "SIGXCPU"; // 24 exceeded CPU time limit
290 case SIGXFSZ:
291 return "SIGXFSZ"; // 25 exceeded file size limit
292 case SIGVTALRM:
293 return "SIGVTALRM"; // 26 virtual time alarm
294 case SIGPROF:
295 return "SIGPROF"; // 27 profiling time alarm
296#if defined(SIGWINCH)
297 case SIGWINCH:
298 return "SIGWINCH"; // 28 window size changes
299#endif
300#if defined(SIGINFO)
301 case SIGINFO:
302 return "SIGINFO"; // 29 information request
303#endif
304 case SIGUSR1:
305 return "SIGUSR1"; // 30 user defined signal 1
306 case SIGUSR2:
307 return "SIGUSR2"; // 31 user defined signal 2
308 default:
309 break;
310 }
311 return nullptr;
312}
313
314#endif
315
316#if !defined(__APPLE__) // see Host.mm
317
318bool Host::GetBundleDirectory(const FileSpec &file, FileSpec &bundle) {
319 bundle.Clear();
320 return false;
321}
322
323bool Host::ResolveExecutableInBundle(FileSpec &file) { return false; }
324#endif
325
326#ifndef _WIN32
327
328FileSpec Host::GetModuleFileSpecForHostAddress(const void *host_addr) {
329 FileSpec module_filespec;
330#if !defined(__ANDROID__)
331 Dl_info info;
332 if (::dladdr(address: host_addr, info: &info)) {
333 if (info.dli_fname) {
334 module_filespec.SetFile(path: info.dli_fname, style: FileSpec::Style::native);
335 FileSystem::Instance().Resolve(file_spec&: module_filespec);
336 }
337 }
338#endif
339 return module_filespec;
340}
341
342#endif
343
344#if !defined(__linux__)
345bool Host::FindProcessThreads(const lldb::pid_t pid, TidMap &tids_to_attach) {
346 return false;
347}
348#endif
349
350struct ShellInfo {
351 ShellInfo() : process_reaped(false) {}
352
353 lldb_private::Predicate<bool> process_reaped;
354 lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
355 int signo = -1;
356 int status = -1;
357};
358
359static void
360MonitorShellCommand(std::shared_ptr<ShellInfo> shell_info, lldb::pid_t pid,
361 int signo, // Zero for no signal
362 int status) // Exit value of process if signal is zero
363{
364 shell_info->pid = pid;
365 shell_info->signo = signo;
366 shell_info->status = status;
367 // Let the thread running Host::RunShellCommand() know that the process
368 // exited and that ShellInfo has been filled in by broadcasting to it
369 shell_info->process_reaped.SetValue(value: true, broadcast_type: eBroadcastAlways);
370}
371
372Status Host::RunShellCommand(llvm::StringRef command,
373 const FileSpec &working_dir, int *status_ptr,
374 int *signo_ptr, std::string *command_output_ptr,
375 const Timeout<std::micro> &timeout,
376 bool run_in_shell, bool hide_stderr) {
377 return RunShellCommand(shell: llvm::StringRef(), args: Args(command), working_dir,
378 status_ptr, signo_ptr, command_output: command_output_ptr, timeout,
379 run_in_shell, hide_stderr);
380}
381
382Status Host::RunShellCommand(llvm::StringRef shell_path,
383 llvm::StringRef command,
384 const FileSpec &working_dir, int *status_ptr,
385 int *signo_ptr, std::string *command_output_ptr,
386 const Timeout<std::micro> &timeout,
387 bool run_in_shell, bool hide_stderr) {
388 return RunShellCommand(shell: shell_path, args: Args(command), working_dir, status_ptr,
389 signo_ptr, command_output: command_output_ptr, timeout, run_in_shell,
390 hide_stderr);
391}
392
393Status Host::RunShellCommand(const Args &args, const FileSpec &working_dir,
394 int *status_ptr, int *signo_ptr,
395 std::string *command_output_ptr,
396 const Timeout<std::micro> &timeout,
397 bool run_in_shell, bool hide_stderr) {
398 return RunShellCommand(shell: llvm::StringRef(), args, working_dir, status_ptr,
399 signo_ptr, command_output: command_output_ptr, timeout, run_in_shell,
400 hide_stderr);
401}
402
403Status Host::RunShellCommand(llvm::StringRef shell_path, const Args &args,
404 const FileSpec &working_dir, int *status_ptr,
405 int *signo_ptr, std::string *command_output_ptr,
406 const Timeout<std::micro> &timeout,
407 bool run_in_shell, bool hide_stderr) {
408 Status error;
409 ProcessLaunchInfo launch_info;
410 launch_info.SetArchitecture(HostInfo::GetArchitecture());
411 if (run_in_shell) {
412 // Run the command in a shell
413 FileSpec shell = HostInfo::GetDefaultShell();
414 if (!shell_path.empty())
415 shell.SetPath(shell_path);
416
417 launch_info.SetShell(shell);
418 launch_info.GetArguments().AppendArguments(rhs: args);
419 const bool will_debug = false;
420 const bool first_arg_is_full_shell_command = false;
421 launch_info.ConvertArgumentsForLaunchingInShell(
422 error, will_debug, first_arg_is_full_shell_command, num_resumes: 0);
423 } else {
424 // No shell, just run it
425 const bool first_arg_is_executable = true;
426 launch_info.SetArguments(args, first_arg_is_executable);
427 }
428
429 launch_info.GetEnvironment() = Host::GetEnvironment();
430
431 if (working_dir)
432 launch_info.SetWorkingDirectory(working_dir);
433 llvm::SmallString<64> output_file_path;
434
435 if (command_output_ptr) {
436 // Create a temporary file to get the stdout/stderr and redirect the output
437 // of the command into this file. We will later read this file if all goes
438 // well and fill the data into "command_output_ptr"
439 if (FileSpec tmpdir_file_spec = HostInfo::GetProcessTempDir()) {
440 tmpdir_file_spec.AppendPathComponent(component: "lldb-shell-output.%%%%%%");
441 llvm::sys::fs::createUniqueFile(Model: tmpdir_file_spec.GetPath(),
442 ResultPath&: output_file_path);
443 } else {
444 llvm::sys::fs::createTemporaryFile(Prefix: "lldb-shell-output.%%%%%%", Suffix: "",
445 ResultPath&: output_file_path);
446 }
447 }
448
449 FileSpec output_file_spec(output_file_path.str());
450 // Set up file descriptors.
451 launch_info.AppendSuppressFileAction(STDIN_FILENO, read: true, write: false);
452 if (output_file_spec)
453 launch_info.AppendOpenFileAction(STDOUT_FILENO, file_spec: output_file_spec, read: false,
454 write: true);
455 else
456 launch_info.AppendSuppressFileAction(STDOUT_FILENO, read: false, write: true);
457
458 if (output_file_spec && !hide_stderr)
459 launch_info.AppendDuplicateFileAction(STDOUT_FILENO, STDERR_FILENO);
460 else
461 launch_info.AppendSuppressFileAction(STDERR_FILENO, read: false, write: true);
462
463 std::shared_ptr<ShellInfo> shell_info_sp(new ShellInfo());
464 launch_info.SetMonitorProcessCallback(
465 std::bind(f&: MonitorShellCommand, args&: shell_info_sp, args: std::placeholders::_1,
466 args: std::placeholders::_2, args: std::placeholders::_3));
467
468 error = LaunchProcess(launch_info);
469 const lldb::pid_t pid = launch_info.GetProcessID();
470
471 if (error.Success() && pid == LLDB_INVALID_PROCESS_ID)
472 error.SetErrorString("failed to get process ID");
473
474 if (error.Success()) {
475 if (!shell_info_sp->process_reaped.WaitForValueEqualTo(value: true, timeout)) {
476 error.SetErrorString("timed out waiting for shell command to complete");
477
478 // Kill the process since it didn't complete within the timeout specified
479 Kill(pid, SIGKILL);
480 // Wait for the monitor callback to get the message
481 shell_info_sp->process_reaped.WaitForValueEqualTo(
482 value: true, timeout: std::chrono::seconds(1));
483 } else {
484 if (status_ptr)
485 *status_ptr = shell_info_sp->status;
486
487 if (signo_ptr)
488 *signo_ptr = shell_info_sp->signo;
489
490 if (command_output_ptr) {
491 command_output_ptr->clear();
492 uint64_t file_size =
493 FileSystem::Instance().GetByteSize(file_spec: output_file_spec);
494 if (file_size > 0) {
495 if (file_size > command_output_ptr->max_size()) {
496 error.SetErrorStringWithFormat(
497 "shell command output is too large to fit into a std::string");
498 } else {
499 WritableDataBufferSP Buffer =
500 FileSystem::Instance().CreateWritableDataBuffer(
501 file_spec: output_file_spec);
502 if (error.Success())
503 command_output_ptr->assign(
504 s: reinterpret_cast<char *>(Buffer->GetBytes()),
505 n: Buffer->GetByteSize());
506 }
507 }
508 }
509 }
510 }
511
512 llvm::sys::fs::remove(path: output_file_spec.GetPath());
513 return error;
514}
515
516// The functions below implement process launching for non-Apple-based
517// platforms
518#if !defined(__APPLE__)
519Status Host::LaunchProcess(ProcessLaunchInfo &launch_info) {
520 std::unique_ptr<ProcessLauncher> delegate_launcher;
521#if defined(_WIN32)
522 delegate_launcher.reset(new ProcessLauncherWindows());
523#else
524 delegate_launcher.reset(p: new ProcessLauncherPosixFork());
525#endif
526 MonitoringProcessLauncher launcher(std::move(delegate_launcher));
527
528 Status error;
529 HostProcess process = launcher.LaunchProcess(launch_info, error);
530
531 // TODO(zturner): It would be better if the entire HostProcess were returned
532 // instead of writing it into this structure.
533 launch_info.SetProcessID(process.GetProcessId());
534
535 return error;
536}
537#endif // !defined(__APPLE__)
538
539#ifndef _WIN32
540void Host::Kill(lldb::pid_t pid, int signo) { ::kill(pid: pid, sig: signo); }
541
542#endif
543
544#if !defined(__APPLE__)
545llvm::Error Host::OpenFileInExternalEditor(llvm::StringRef editor,
546 const FileSpec &file_spec,
547 uint32_t line_no) {
548 return llvm::errorCodeToError(
549 EC: std::error_code(ENOTSUP, std::system_category()));
550}
551
552bool Host::IsInteractiveGraphicSession() { return false; }
553#endif
554
555std::unique_ptr<Connection> Host::CreateDefaultConnection(llvm::StringRef url) {
556#if defined(_WIN32)
557 if (url.starts_with("file://"))
558 return std::unique_ptr<Connection>(new ConnectionGenericFile());
559#endif
560 return std::unique_ptr<Connection>(new ConnectionFileDescriptor());
561}
562
563#if defined(LLVM_ON_UNIX)
564WaitStatus WaitStatus::Decode(int wstatus) {
565 if (WIFEXITED(wstatus))
566 return {Exit, uint8_t(WEXITSTATUS(wstatus))};
567 else if (WIFSIGNALED(wstatus))
568 return {Signal, uint8_t(WTERMSIG(wstatus))};
569 else if (WIFSTOPPED(wstatus))
570 return {Stop, uint8_t(WSTOPSIG(wstatus))};
571 llvm_unreachable("Unknown wait status");
572}
573#endif
574
575void llvm::format_provider<WaitStatus>::format(const WaitStatus &WS,
576 raw_ostream &OS,
577 StringRef Options) {
578 if (Options == "g") {
579 char type;
580 switch (WS.type) {
581 case WaitStatus::Exit:
582 type = 'W';
583 break;
584 case WaitStatus::Signal:
585 type = 'X';
586 break;
587 case WaitStatus::Stop:
588 type = 'S';
589 break;
590 }
591 OS << formatv(Fmt: "{0}{1:x-2}", Vals&: type, Vals: WS.status);
592 return;
593 }
594
595 assert(Options.empty());
596 const char *desc;
597 switch(WS.type) {
598 case WaitStatus::Exit:
599 desc = "Exited with status";
600 break;
601 case WaitStatus::Signal:
602 desc = "Killed by signal";
603 break;
604 case WaitStatus::Stop:
605 desc = "Stopped by signal";
606 break;
607 }
608 OS << desc << " " << int(WS.status);
609}
610
611uint32_t Host::FindProcesses(const ProcessInstanceInfoMatch &match_info,
612 ProcessInstanceInfoList &process_infos) {
613 return FindProcessesImpl(match_info, proc_infos&: process_infos);
614}
615
616char SystemLogHandler::ID;
617
618SystemLogHandler::SystemLogHandler() {}
619
620void SystemLogHandler::Emit(llvm::StringRef message) {
621 Host::SystemLog(message);
622}
623

source code of lldb/source/Host/common/Host.cpp