1 //===-- Host.cpp ------------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // C includes
11 #include <errno.h>
12 #include <limits.h>
13 #include <stdlib.h>
14 #include <sys/types.h>
15 #ifndef _WIN32
16 #include <unistd.h>
17 #include <dlfcn.h>
18 #include <grp.h>
19 #include <netdb.h>
20 #include <pwd.h>
21 #include <sys/stat.h>
22 #endif
23 
24 #if defined (__APPLE__)
25 #include <mach/mach_port.h>
26 #include <mach/mach_init.h>
27 #include <mach-o/dyld.h>
28 #endif
29 
30 #if defined (__linux__) || defined (__FreeBSD__) || defined (__FreeBSD_kernel__) || defined (__APPLE__) || defined(__NetBSD__)
31 #if !defined(__ANDROID__) && !defined(__ANDROID_NDK__)
32 #include <spawn.h>
33 #endif
34 #include <sys/wait.h>
35 #include <sys/syscall.h>
36 #endif
37 
38 #if defined (__FreeBSD__)
39 #include <pthread_np.h>
40 #endif
41 
42 // C++ includes
43 #include <limits>
44 
45 #include "lldb/Host/FileSystem.h"
46 #include "lldb/Host/Host.h"
47 #include "lldb/Host/HostInfo.h"
48 #include "lldb/Core/ArchSpec.h"
49 #include "lldb/Core/Error.h"
50 #include "lldb/Core/Log.h"
51 #include "lldb/Host/FileSpec.h"
52 #include "lldb/Host/HostProcess.h"
53 #include "lldb/Host/MonitoringProcessLauncher.h"
54 #include "lldb/Host/Predicate.h"
55 #include "lldb/Host/ProcessLauncher.h"
56 #include "lldb/Host/ThreadLauncher.h"
57 #include "lldb/lldb-private-forward.h"
58 #include "llvm/Support/FileSystem.h"
59 #include "lldb/Target/FileAction.h"
60 #include "lldb/Target/ProcessLaunchInfo.h"
61 #include "lldb/Target/UnixSignals.h"
62 #include "lldb/Utility/CleanUp.h"
63 #include "llvm/ADT/SmallString.h"
64 
65 #if defined(_WIN32)
66 #include "lldb/Host/windows/ProcessLauncherWindows.h"
67 #elif defined(__ANDROID__) || defined(__ANDROID_NDK__)
68 #include "lldb/Host/android/ProcessLauncherAndroid.h"
69 #else
70 #include "lldb/Host/posix/ProcessLauncherPosix.h"
71 #endif
72 
73 #if defined (__APPLE__)
74 #ifndef _POSIX_SPAWN_DISABLE_ASLR
75 #define _POSIX_SPAWN_DISABLE_ASLR       0x0100
76 #endif
77 
78 extern "C"
79 {
80     int __pthread_chdir(const char *path);
81     int __pthread_fchdir (int fildes);
82 }
83 
84 #endif
85 
86 using namespace lldb;
87 using namespace lldb_private;
88 
89 #if !defined (__APPLE__) && !defined (_WIN32)
90 struct MonitorInfo
91 {
92     lldb::pid_t pid;                            // The process ID to monitor
93     Host::MonitorChildProcessCallback callback; // The callback function to call when "pid" exits or signals
94     void *callback_baton;                       // The callback baton for the callback function
95     bool monitor_signals;                       // If true, call the callback when "pid" gets signaled.
96 };
97 
98 static thread_result_t
99 MonitorChildProcessThreadFunction (void *arg);
100 
101 HostThread
102 Host::StartMonitoringChildProcess(Host::MonitorChildProcessCallback callback, void *callback_baton, lldb::pid_t pid, bool monitor_signals)
103 {
104     MonitorInfo * info_ptr = new MonitorInfo();
105 
106     info_ptr->pid = pid;
107     info_ptr->callback = callback;
108     info_ptr->callback_baton = callback_baton;
109     info_ptr->monitor_signals = monitor_signals;
110 
111     char thread_name[256];
112     ::snprintf(thread_name, sizeof(thread_name), "<lldb.host.wait4(pid=%" PRIu64 ")>", pid);
113     return ThreadLauncher::LaunchThread(thread_name, MonitorChildProcessThreadFunction, info_ptr, NULL);
114 }
115 
116 #ifndef __linux__
117 //------------------------------------------------------------------
118 // Scoped class that will disable thread canceling when it is
119 // constructed, and exception safely restore the previous value it
120 // when it goes out of scope.
121 //------------------------------------------------------------------
122 class ScopedPThreadCancelDisabler
123 {
124 public:
125     ScopedPThreadCancelDisabler()
126     {
127         // Disable the ability for this thread to be cancelled
128         int err = ::pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &m_old_state);
129         if (err != 0)
130             m_old_state = -1;
131     }
132 
133     ~ScopedPThreadCancelDisabler()
134     {
135         // Restore the ability for this thread to be cancelled to what it
136         // previously was.
137         if (m_old_state != -1)
138             ::pthread_setcancelstate (m_old_state, 0);
139     }
140 private:
141     int m_old_state;    // Save the old cancelability state.
142 };
143 #endif // __linux__
144 
145 #ifdef __linux__
146 static thread_local volatile sig_atomic_t g_usr1_called;
147 
148 static void
149 SigUsr1Handler (int)
150 {
151     g_usr1_called = 1;
152 }
153 #endif // __linux__
154 
155 static bool
156 CheckForMonitorCancellation()
157 {
158 #ifdef __linux__
159     if (g_usr1_called)
160     {
161         g_usr1_called = 0;
162         return true;
163     }
164 #else
165     ::pthread_testcancel ();
166 #endif
167     return false;
168 }
169 
170 static thread_result_t
171 MonitorChildProcessThreadFunction (void *arg)
172 {
173     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
174     const char *function = __FUNCTION__;
175     if (log)
176         log->Printf ("%s (arg = %p) thread starting...", function, arg);
177 
178     MonitorInfo *info = (MonitorInfo *)arg;
179 
180     const Host::MonitorChildProcessCallback callback = info->callback;
181     void * const callback_baton = info->callback_baton;
182     const bool monitor_signals = info->monitor_signals;
183 
184     assert (info->pid <= UINT32_MAX);
185     const ::pid_t pid = monitor_signals ? -1 * getpgid(info->pid) : info->pid;
186 
187     delete info;
188 
189     int status = -1;
190 #if defined (__FreeBSD__) || defined (__FreeBSD_kernel__)
191     #define __WALL 0
192 #endif
193     const int options = __WALL;
194 
195 #ifdef __linux__
196     // This signal is only used to interrupt the thread from waitpid
197     struct sigaction sigUsr1Action;
198     memset(&sigUsr1Action, 0, sizeof(sigUsr1Action));
199     sigUsr1Action.sa_handler = SigUsr1Handler;
200     ::sigaction(SIGUSR1, &sigUsr1Action, nullptr);
201 #endif // __linux__
202 
203     while (1)
204     {
205         log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS);
206         if (log)
207             log->Printf("%s ::waitpid (pid = %" PRIi32 ", &status, options = %i)...", function, pid, options);
208 
209         if (CheckForMonitorCancellation ())
210             break;
211 
212         // Get signals from all children with same process group of pid
213         const ::pid_t wait_pid = ::waitpid (pid, &status, options);
214 
215         if (CheckForMonitorCancellation ())
216             break;
217 
218         if (wait_pid == -1)
219         {
220             if (errno == EINTR)
221                 continue;
222             else
223             {
224                 if (log)
225                     log->Printf ("%s (arg = %p) thread exiting because waitpid failed (%s)...", __FUNCTION__, arg, strerror(errno));
226                 break;
227             }
228         }
229         else if (wait_pid > 0)
230         {
231             bool exited = false;
232             int signal = 0;
233             int exit_status = 0;
234             const char *status_cstr = NULL;
235             if (WIFSTOPPED(status))
236             {
237                 signal = WSTOPSIG(status);
238                 status_cstr = "STOPPED";
239             }
240             else if (WIFEXITED(status))
241             {
242                 exit_status = WEXITSTATUS(status);
243                 status_cstr = "EXITED";
244                 exited = true;
245             }
246             else if (WIFSIGNALED(status))
247             {
248                 signal = WTERMSIG(status);
249                 status_cstr = "SIGNALED";
250                 if (wait_pid == abs(pid)) {
251                     exited = true;
252                     exit_status = -1;
253                 }
254             }
255             else
256             {
257                 status_cstr = "(\?\?\?)";
258             }
259 
260             // Scope for pthread_cancel_disabler
261             {
262 #ifndef __linux__
263                 ScopedPThreadCancelDisabler pthread_cancel_disabler;
264 #endif
265 
266                 log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS);
267                 if (log)
268                     log->Printf ("%s ::waitpid (pid = %" PRIi32 ", &status, options = %i) => pid = %" PRIi32 ", status = 0x%8.8x (%s), signal = %i, exit_state = %i",
269                                  function,
270                                  pid,
271                                  options,
272                                  wait_pid,
273                                  status,
274                                  status_cstr,
275                                  signal,
276                                  exit_status);
277 
278                 if (exited || (signal != 0 && monitor_signals))
279                 {
280                     bool callback_return = false;
281                     if (callback)
282                         callback_return = callback (callback_baton, wait_pid, exited, signal, exit_status);
283 
284                     // If our process exited, then this thread should exit
285                     if (exited && wait_pid == abs(pid))
286                     {
287                         if (log)
288                             log->Printf ("%s (arg = %p) thread exiting because pid received exit signal...", __FUNCTION__, arg);
289                         break;
290                     }
291                     // If the callback returns true, it means this process should
292                     // exit
293                     if (callback_return)
294                     {
295                         if (log)
296                             log->Printf ("%s (arg = %p) thread exiting because callback returned true...", __FUNCTION__, arg);
297                         break;
298                     }
299                 }
300             }
301         }
302     }
303 
304     log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS);
305     if (log)
306         log->Printf ("%s (arg = %p) thread exiting...", __FUNCTION__, arg);
307 
308     return NULL;
309 }
310 
311 #endif // #if !defined (__APPLE__) && !defined (_WIN32)
312 
313 #if !defined (__APPLE__)
314 
315 void
316 Host::SystemLog (SystemLogType type, const char *format, va_list args)
317 {
318     vfprintf (stderr, format, args);
319 }
320 
321 #endif
322 
323 void
324 Host::SystemLog (SystemLogType type, const char *format, ...)
325 {
326     va_list args;
327     va_start (args, format);
328     SystemLog (type, format, args);
329     va_end (args);
330 }
331 
332 lldb::pid_t
333 Host::GetCurrentProcessID()
334 {
335     return ::getpid();
336 }
337 
338 #ifndef _WIN32
339 
340 lldb::tid_t
341 Host::GetCurrentThreadID()
342 {
343 #if defined (__APPLE__)
344     // Calling "mach_thread_self()" bumps the reference count on the thread
345     // port, so we need to deallocate it. mach_task_self() doesn't bump the ref
346     // count.
347     thread_port_t thread_self = mach_thread_self();
348     mach_port_deallocate(mach_task_self(), thread_self);
349     return thread_self;
350 #elif defined(__FreeBSD__)
351     return lldb::tid_t(pthread_getthreadid_np());
352 #elif defined(__ANDROID_NDK__)
353     return lldb::tid_t(gettid());
354 #elif defined(__linux__)
355     return lldb::tid_t(syscall(SYS_gettid));
356 #else
357     return lldb::tid_t(pthread_self());
358 #endif
359 }
360 
361 lldb::thread_t
362 Host::GetCurrentThread ()
363 {
364     return lldb::thread_t(pthread_self());
365 }
366 
367 const char *
368 Host::GetSignalAsCString (int signo)
369 {
370     switch (signo)
371     {
372     case SIGHUP:    return "SIGHUP";    // 1    hangup
373     case SIGINT:    return "SIGINT";    // 2    interrupt
374     case SIGQUIT:   return "SIGQUIT";   // 3    quit
375     case SIGILL:    return "SIGILL";    // 4    illegal instruction (not reset when caught)
376     case SIGTRAP:   return "SIGTRAP";   // 5    trace trap (not reset when caught)
377     case SIGABRT:   return "SIGABRT";   // 6    abort()
378 #if  defined(SIGPOLL)
379 #if !defined(SIGIO) || (SIGPOLL != SIGIO)
380 // Under some GNU/Linux, SIGPOLL and SIGIO are the same. Causing the build to
381 // fail with 'multiple define cases with same value'
382     case SIGPOLL:   return "SIGPOLL";   // 7    pollable event ([XSR] generated, not supported)
383 #endif
384 #endif
385 #if  defined(SIGEMT)
386     case SIGEMT:    return "SIGEMT";    // 7    EMT instruction
387 #endif
388     case SIGFPE:    return "SIGFPE";    // 8    floating point exception
389     case SIGKILL:   return "SIGKILL";   // 9    kill (cannot be caught or ignored)
390     case SIGBUS:    return "SIGBUS";    // 10    bus error
391     case SIGSEGV:   return "SIGSEGV";   // 11    segmentation violation
392     case SIGSYS:    return "SIGSYS";    // 12    bad argument to system call
393     case SIGPIPE:   return "SIGPIPE";   // 13    write on a pipe with no one to read it
394     case SIGALRM:   return "SIGALRM";   // 14    alarm clock
395     case SIGTERM:   return "SIGTERM";   // 15    software termination signal from kill
396     case SIGURG:    return "SIGURG";    // 16    urgent condition on IO channel
397     case SIGSTOP:   return "SIGSTOP";   // 17    sendable stop signal not from tty
398     case SIGTSTP:   return "SIGTSTP";   // 18    stop signal from tty
399     case SIGCONT:   return "SIGCONT";   // 19    continue a stopped process
400     case SIGCHLD:   return "SIGCHLD";   // 20    to parent on child stop or exit
401     case SIGTTIN:   return "SIGTTIN";   // 21    to readers pgrp upon background tty read
402     case SIGTTOU:   return "SIGTTOU";   // 22    like TTIN for output if (tp->t_local&LTOSTOP)
403 #if  defined(SIGIO)
404     case SIGIO:     return "SIGIO";     // 23    input/output possible signal
405 #endif
406     case SIGXCPU:   return "SIGXCPU";   // 24    exceeded CPU time limit
407     case SIGXFSZ:   return "SIGXFSZ";   // 25    exceeded file size limit
408     case SIGVTALRM: return "SIGVTALRM"; // 26    virtual time alarm
409     case SIGPROF:   return "SIGPROF";   // 27    profiling time alarm
410 #if  defined(SIGWINCH)
411     case SIGWINCH:  return "SIGWINCH";  // 28    window size changes
412 #endif
413 #if  defined(SIGINFO)
414     case SIGINFO:   return "SIGINFO";   // 29    information request
415 #endif
416     case SIGUSR1:   return "SIGUSR1";   // 30    user defined signal 1
417     case SIGUSR2:   return "SIGUSR2";   // 31    user defined signal 2
418     default:
419         break;
420     }
421     return NULL;
422 }
423 
424 #endif
425 
426 #ifndef _WIN32
427 
428 lldb::thread_key_t
429 Host::ThreadLocalStorageCreate(ThreadLocalStorageCleanupCallback callback)
430 {
431     pthread_key_t key;
432     ::pthread_key_create (&key, callback);
433     return key;
434 }
435 
436 void*
437 Host::ThreadLocalStorageGet(lldb::thread_key_t key)
438 {
439     return ::pthread_getspecific (key);
440 }
441 
442 void
443 Host::ThreadLocalStorageSet(lldb::thread_key_t key, void *value)
444 {
445    ::pthread_setspecific (key, value);
446 }
447 
448 #endif
449 
450 #if !defined (__APPLE__) // see Host.mm
451 
452 bool
453 Host::GetBundleDirectory (const FileSpec &file, FileSpec &bundle)
454 {
455     bundle.Clear();
456     return false;
457 }
458 
459 bool
460 Host::ResolveExecutableInBundle (FileSpec &file)
461 {
462     return false;
463 }
464 #endif
465 
466 #ifndef _WIN32
467 
468 FileSpec
469 Host::GetModuleFileSpecForHostAddress (const void *host_addr)
470 {
471     FileSpec module_filespec;
472 #if !defined(__ANDROID__) && !defined(__ANDROID_NDK__)
473     Dl_info info;
474     if (::dladdr (host_addr, &info))
475     {
476         if (info.dli_fname)
477             module_filespec.SetFile(info.dli_fname, true);
478     }
479 #endif
480     return module_filespec;
481 }
482 
483 #endif
484 
485 #if !defined(__linux__)
486 bool
487 Host::FindProcessThreads (const lldb::pid_t pid, TidMap &tids_to_attach)
488 {
489     return false;
490 }
491 #endif
492 
493 struct ShellInfo
494 {
495     ShellInfo () :
496         process_reaped (false),
497         can_delete (false),
498         pid (LLDB_INVALID_PROCESS_ID),
499         signo(-1),
500         status(-1)
501     {
502     }
503 
504     lldb_private::Predicate<bool> process_reaped;
505     lldb_private::Predicate<bool> can_delete;
506     lldb::pid_t pid;
507     int signo;
508     int status;
509 };
510 
511 static bool
512 MonitorShellCommand (void *callback_baton,
513                      lldb::pid_t pid,
514                      bool exited,       // True if the process did exit
515                      int signo,         // Zero for no signal
516                      int status)   // Exit value of process if signal is zero
517 {
518     ShellInfo *shell_info = (ShellInfo *)callback_baton;
519     shell_info->pid = pid;
520     shell_info->signo = signo;
521     shell_info->status = status;
522     // Let the thread running Host::RunShellCommand() know that the process
523     // exited and that ShellInfo has been filled in by broadcasting to it
524     shell_info->process_reaped.SetValue(1, eBroadcastAlways);
525     // Now wait for a handshake back from that thread running Host::RunShellCommand
526     // so we know that we can delete shell_info_ptr
527     shell_info->can_delete.WaitForValueEqualTo(true);
528     // Sleep a bit to allow the shell_info->can_delete.SetValue() to complete...
529     usleep(1000);
530     // Now delete the shell info that was passed into this function
531     delete shell_info;
532     return true;
533 }
534 
535 Error
536 Host::RunShellCommand(const char *command,
537                       const FileSpec &working_dir,
538                       int *status_ptr,
539                       int *signo_ptr,
540                       std::string *command_output_ptr,
541                       uint32_t timeout_sec,
542                       bool run_in_default_shell)
543 {
544     return RunShellCommand(Args(command), working_dir, status_ptr, signo_ptr, command_output_ptr, timeout_sec, run_in_default_shell);
545 }
546 
547 Error
548 Host::RunShellCommand(const Args &args,
549                       const FileSpec &working_dir,
550                       int *status_ptr,
551                       int *signo_ptr,
552                       std::string *command_output_ptr,
553                       uint32_t timeout_sec,
554                       bool run_in_default_shell)
555 {
556     Error error;
557     ProcessLaunchInfo launch_info;
558     launch_info.SetArchitecture(HostInfo::GetArchitecture());
559     if (run_in_default_shell)
560     {
561         // Run the command in a shell
562         launch_info.SetShell(HostInfo::GetDefaultShell());
563         launch_info.GetArguments().AppendArguments(args);
564         const bool localhost = true;
565         const bool will_debug = false;
566         const bool first_arg_is_full_shell_command = false;
567         launch_info.ConvertArgumentsForLaunchingInShell (error,
568                                                          localhost,
569                                                          will_debug,
570                                                          first_arg_is_full_shell_command,
571                                                          0);
572     }
573     else
574     {
575         // No shell, just run it
576         const bool first_arg_is_executable = true;
577         launch_info.SetArguments(args, first_arg_is_executable);
578     }
579 
580     if (working_dir)
581         launch_info.SetWorkingDirectory(working_dir);
582     llvm::SmallString<PATH_MAX> output_file_path;
583 
584     if (command_output_ptr)
585     {
586         // Create a temporary file to get the stdout/stderr and redirect the
587         // output of the command into this file. We will later read this file
588         // if all goes well and fill the data into "command_output_ptr"
589         FileSpec tmpdir_file_spec;
590         if (HostInfo::GetLLDBPath(ePathTypeLLDBTempSystemDir, tmpdir_file_spec))
591         {
592             tmpdir_file_spec.AppendPathComponent("lldb-shell-output.%%%%%%");
593             llvm::sys::fs::createUniqueFile(tmpdir_file_spec.GetPath().c_str(), output_file_path);
594         }
595         else
596         {
597             llvm::sys::fs::createTemporaryFile("lldb-shell-output.%%%%%%", "", output_file_path);
598         }
599     }
600 
601     FileSpec output_file_spec{output_file_path.c_str(), false};
602 
603     launch_info.AppendSuppressFileAction (STDIN_FILENO, true, false);
604     if (output_file_spec)
605     {
606         launch_info.AppendOpenFileAction(STDOUT_FILENO, output_file_spec, false, true);
607         launch_info.AppendDuplicateFileAction(STDOUT_FILENO, STDERR_FILENO);
608     }
609     else
610     {
611         launch_info.AppendSuppressFileAction (STDOUT_FILENO, false, true);
612         launch_info.AppendSuppressFileAction (STDERR_FILENO, false, true);
613     }
614 
615     // The process monitor callback will delete the 'shell_info_ptr' below...
616     std::unique_ptr<ShellInfo> shell_info_ap (new ShellInfo());
617 
618     const bool monitor_signals = false;
619     launch_info.SetMonitorProcessCallback(MonitorShellCommand, shell_info_ap.get(), monitor_signals);
620 
621     error = LaunchProcess (launch_info);
622     const lldb::pid_t pid = launch_info.GetProcessID();
623 
624     if (error.Success() && pid == LLDB_INVALID_PROCESS_ID)
625         error.SetErrorString("failed to get process ID");
626 
627     if (error.Success())
628     {
629         // The process successfully launched, so we can defer ownership of
630         // "shell_info" to the MonitorShellCommand callback function that will
631         // get called when the process dies. We release the unique pointer as it
632         // doesn't need to delete the ShellInfo anymore.
633         ShellInfo *shell_info = shell_info_ap.release();
634         TimeValue *timeout_ptr = nullptr;
635         TimeValue timeout_time(TimeValue::Now());
636         if (timeout_sec > 0) {
637             timeout_time.OffsetWithSeconds(timeout_sec);
638             timeout_ptr = &timeout_time;
639         }
640         bool timed_out = false;
641         shell_info->process_reaped.WaitForValueEqualTo(true, timeout_ptr, &timed_out);
642         if (timed_out)
643         {
644             error.SetErrorString("timed out waiting for shell command to complete");
645 
646             // Kill the process since it didn't complete within the timeout specified
647             Kill (pid, SIGKILL);
648             // Wait for the monitor callback to get the message
649             timeout_time = TimeValue::Now();
650             timeout_time.OffsetWithSeconds(1);
651             timed_out = false;
652             shell_info->process_reaped.WaitForValueEqualTo(true, &timeout_time, &timed_out);
653         }
654         else
655         {
656             if (status_ptr)
657                 *status_ptr = shell_info->status;
658 
659             if (signo_ptr)
660                 *signo_ptr = shell_info->signo;
661 
662             if (command_output_ptr)
663             {
664                 command_output_ptr->clear();
665                 uint64_t file_size = output_file_spec.GetByteSize();
666                 if (file_size > 0)
667                 {
668                     if (file_size > command_output_ptr->max_size())
669                     {
670                         error.SetErrorStringWithFormat("shell command output is too large to fit into a std::string");
671                     }
672                     else
673                     {
674                         std::vector<char> command_output(file_size);
675                         output_file_spec.ReadFileContents(0, command_output.data(), file_size, &error);
676                         if (error.Success())
677                             command_output_ptr->assign(command_output.data(), file_size);
678                     }
679                 }
680             }
681         }
682         shell_info->can_delete.SetValue(true, eBroadcastAlways);
683     }
684 
685     if (FileSystem::GetFileExists(output_file_spec))
686         FileSystem::Unlink(output_file_spec);
687     // Handshake with the monitor thread, or just let it know in advance that
688     // it can delete "shell_info" in case we timed out and were not able to kill
689     // the process...
690     return error;
691 }
692 
693 // LaunchProcessPosixSpawn for Apple, Linux, FreeBSD and other GLIBC
694 // systems
695 
696 #if defined (__APPLE__) || defined (__linux__) || defined (__FreeBSD__) || defined (__GLIBC__) || defined(__NetBSD__)
697 #if !defined(__ANDROID__) && !defined(__ANDROID_NDK__)
698 // this method needs to be visible to macosx/Host.cpp and
699 // common/Host.cpp.
700 
701 short
702 Host::GetPosixspawnFlags(const ProcessLaunchInfo &launch_info)
703 {
704     short flags = POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK;
705 
706 #if defined (__APPLE__)
707     if (launch_info.GetFlags().Test (eLaunchFlagExec))
708         flags |= POSIX_SPAWN_SETEXEC;           // Darwin specific posix_spawn flag
709 
710     if (launch_info.GetFlags().Test (eLaunchFlagDebug))
711         flags |= POSIX_SPAWN_START_SUSPENDED;   // Darwin specific posix_spawn flag
712 
713     if (launch_info.GetFlags().Test (eLaunchFlagDisableASLR))
714         flags |= _POSIX_SPAWN_DISABLE_ASLR;     // Darwin specific posix_spawn flag
715 
716     if (launch_info.GetLaunchInSeparateProcessGroup())
717         flags |= POSIX_SPAWN_SETPGROUP;
718 
719 #ifdef POSIX_SPAWN_CLOEXEC_DEFAULT
720 #if defined (__APPLE__) && (defined (__x86_64__) || defined (__i386__))
721     static LazyBool g_use_close_on_exec_flag = eLazyBoolCalculate;
722     if (g_use_close_on_exec_flag == eLazyBoolCalculate)
723     {
724         g_use_close_on_exec_flag = eLazyBoolNo;
725 
726         uint32_t major, minor, update;
727         if (HostInfo::GetOSVersion(major, minor, update))
728         {
729             // Kernel panic if we use the POSIX_SPAWN_CLOEXEC_DEFAULT on 10.7 or earlier
730             if (major > 10 || (major == 10 && minor > 7))
731             {
732                 // Only enable for 10.8 and later OS versions
733                 g_use_close_on_exec_flag = eLazyBoolYes;
734             }
735         }
736     }
737 #else
738     static LazyBool g_use_close_on_exec_flag = eLazyBoolYes;
739 #endif
740     // Close all files exception those with file actions if this is supported.
741     if (g_use_close_on_exec_flag == eLazyBoolYes)
742         flags |= POSIX_SPAWN_CLOEXEC_DEFAULT;
743 #endif
744 #endif // #if defined (__APPLE__)
745     return flags;
746 }
747 
748 Error
749 Host::LaunchProcessPosixSpawn(const char *exe_path, const ProcessLaunchInfo &launch_info, lldb::pid_t &pid)
750 {
751     Error error;
752     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_HOST | LIBLLDB_LOG_PROCESS));
753 
754     posix_spawnattr_t attr;
755     error.SetError( ::posix_spawnattr_init (&attr), eErrorTypePOSIX);
756 
757     if (error.Fail() || log)
758         error.PutToLog(log, "::posix_spawnattr_init ( &attr )");
759     if (error.Fail())
760         return error;
761 
762     // Make a quick class that will cleanup the posix spawn attributes in case
763     // we return in the middle of this function.
764     lldb_utility::CleanUp <posix_spawnattr_t *, int> posix_spawnattr_cleanup(&attr, posix_spawnattr_destroy);
765 
766     sigset_t no_signals;
767     sigset_t all_signals;
768     sigemptyset (&no_signals);
769     sigfillset (&all_signals);
770     ::posix_spawnattr_setsigmask(&attr, &no_signals);
771 #if defined (__linux__)  || defined (__FreeBSD__)
772     ::posix_spawnattr_setsigdefault(&attr, &no_signals);
773 #else
774     ::posix_spawnattr_setsigdefault(&attr, &all_signals);
775 #endif
776 
777     short flags = GetPosixspawnFlags(launch_info);
778 
779     error.SetError( ::posix_spawnattr_setflags (&attr, flags), eErrorTypePOSIX);
780     if (error.Fail() || log)
781         error.PutToLog(log, "::posix_spawnattr_setflags ( &attr, flags=0x%8.8x )", flags);
782     if (error.Fail())
783         return error;
784 
785     // posix_spawnattr_setbinpref_np appears to be an Apple extension per:
786     // http://www.unix.com/man-page/OSX/3/posix_spawnattr_setbinpref_np/
787 #if defined (__APPLE__) && !defined (__arm__)
788 
789     // Don't set the binpref if a shell was provided.  After all, that's only going to affect what version of the shell
790     // is launched, not what fork of the binary is launched.  We insert "arch --arch <ARCH> as part of the shell invocation
791     // to do that job on OSX.
792 
793     if (launch_info.GetShell() == nullptr)
794     {
795         // We don't need to do this for ARM, and we really shouldn't now that we
796         // have multiple CPU subtypes and no posix_spawnattr call that allows us
797         // to set which CPU subtype to launch...
798         const ArchSpec &arch_spec = launch_info.GetArchitecture();
799         cpu_type_t cpu = arch_spec.GetMachOCPUType();
800         cpu_type_t sub = arch_spec.GetMachOCPUSubType();
801         if (cpu != 0 &&
802             cpu != static_cast<cpu_type_t>(UINT32_MAX) &&
803             cpu != static_cast<cpu_type_t>(LLDB_INVALID_CPUTYPE) &&
804             !(cpu == 0x01000007 && sub == 8)) // If haswell is specified, don't try to set the CPU type or we will fail
805         {
806             size_t ocount = 0;
807             error.SetError( ::posix_spawnattr_setbinpref_np (&attr, 1, &cpu, &ocount), eErrorTypePOSIX);
808             if (error.Fail() || log)
809                 error.PutToLog(log, "::posix_spawnattr_setbinpref_np ( &attr, 1, cpu_type = 0x%8.8x, count => %llu )", cpu, (uint64_t)ocount);
810 
811             if (error.Fail() || ocount != 1)
812                 return error;
813         }
814     }
815 
816 #endif
817 
818     const char *tmp_argv[2];
819     char * const *argv = (char * const*)launch_info.GetArguments().GetConstArgumentVector();
820     char * const *envp = (char * const*)launch_info.GetEnvironmentEntries().GetConstArgumentVector();
821     if (argv == NULL)
822     {
823         // posix_spawn gets very unhappy if it doesn't have at least the program
824         // name in argv[0]. One of the side affects I have noticed is the environment
825         // variables don't make it into the child process if "argv == NULL"!!!
826         tmp_argv[0] = exe_path;
827         tmp_argv[1] = NULL;
828         argv = (char * const*)tmp_argv;
829     }
830 
831 #if !defined (__APPLE__)
832     // manage the working directory
833     char current_dir[PATH_MAX];
834     current_dir[0] = '\0';
835 #endif
836 
837     FileSpec working_dir{launch_info.GetWorkingDirectory()};
838     if (working_dir)
839     {
840 #if defined (__APPLE__)
841         // Set the working directory on this thread only
842         if (__pthread_chdir(working_dir.GetCString()) < 0) {
843             if (errno == ENOENT) {
844                 error.SetErrorStringWithFormat("No such file or directory: %s",
845                         working_dir.GetCString());
846             } else if (errno == ENOTDIR) {
847                 error.SetErrorStringWithFormat("Path doesn't name a directory: %s",
848                         working_dir.GetCString());
849             } else {
850                 error.SetErrorStringWithFormat("An unknown error occurred when changing directory for process execution.");
851             }
852             return error;
853         }
854 #else
855         if (::getcwd(current_dir, sizeof(current_dir)) == NULL)
856         {
857             error.SetError(errno, eErrorTypePOSIX);
858             error.LogIfError(log, "unable to save the current directory");
859             return error;
860         }
861 
862         if (::chdir(working_dir.GetCString()) == -1)
863         {
864             error.SetError(errno, eErrorTypePOSIX);
865             error.LogIfError(log, "unable to change working directory to %s",
866                     working_dir.GetCString());
867             return error;
868         }
869 #endif
870     }
871 
872     ::pid_t result_pid = LLDB_INVALID_PROCESS_ID;
873     const size_t num_file_actions = launch_info.GetNumFileActions ();
874     if (num_file_actions > 0)
875     {
876         posix_spawn_file_actions_t file_actions;
877         error.SetError( ::posix_spawn_file_actions_init (&file_actions), eErrorTypePOSIX);
878         if (error.Fail() || log)
879             error.PutToLog(log, "::posix_spawn_file_actions_init ( &file_actions )");
880         if (error.Fail())
881             return error;
882 
883         // Make a quick class that will cleanup the posix spawn attributes in case
884         // we return in the middle of this function.
885         lldb_utility::CleanUp <posix_spawn_file_actions_t *, int> posix_spawn_file_actions_cleanup (&file_actions, posix_spawn_file_actions_destroy);
886 
887         for (size_t i=0; i<num_file_actions; ++i)
888         {
889             const FileAction *launch_file_action = launch_info.GetFileActionAtIndex(i);
890             if (launch_file_action)
891             {
892                 if (!AddPosixSpawnFileAction(&file_actions, launch_file_action, log, error))
893                     return error;
894             }
895         }
896 
897         error.SetError(::posix_spawnp(&result_pid, exe_path, &file_actions, &attr, argv, envp), eErrorTypePOSIX);
898 
899         if (error.Fail() || log)
900         {
901             error.PutToLog(log, "::posix_spawnp ( pid => %i, path = '%s', file_actions = %p, attr = %p, argv = %p, envp = %p )", result_pid,
902                            exe_path, static_cast<void *>(&file_actions), static_cast<void *>(&attr), reinterpret_cast<const void *>(argv),
903                            reinterpret_cast<const void *>(envp));
904             if (log)
905             {
906                 for (int ii=0; argv[ii]; ++ii)
907                     log->Printf("argv[%i] = '%s'", ii, argv[ii]);
908             }
909         }
910 
911     }
912     else
913     {
914         error.SetError(::posix_spawnp(&result_pid, exe_path, NULL, &attr, argv, envp), eErrorTypePOSIX);
915 
916         if (error.Fail() || log)
917         {
918             error.PutToLog(log, "::posix_spawnp ( pid => %i, path = '%s', file_actions = NULL, attr = %p, argv = %p, envp = %p )",
919                            result_pid, exe_path, static_cast<void *>(&attr), reinterpret_cast<const void *>(argv),
920                            reinterpret_cast<const void *>(envp));
921             if (log)
922             {
923                 for (int ii=0; argv[ii]; ++ii)
924                     log->Printf("argv[%i] = '%s'", ii, argv[ii]);
925             }
926         }
927     }
928     pid = result_pid;
929 
930     if (working_dir)
931     {
932 #if defined (__APPLE__)
933         // No more thread specific current working directory
934         __pthread_fchdir (-1);
935 #else
936         if (::chdir(current_dir) == -1 && error.Success())
937         {
938             error.SetError(errno, eErrorTypePOSIX);
939             error.LogIfError(log, "unable to change current directory back to %s",
940                     current_dir);
941         }
942 #endif
943     }
944 
945     return error;
946 }
947 
948 bool
949 Host::AddPosixSpawnFileAction(void *_file_actions, const FileAction *info, Log *log, Error &error)
950 {
951     if (info == NULL)
952         return false;
953 
954     posix_spawn_file_actions_t *file_actions = reinterpret_cast<posix_spawn_file_actions_t *>(_file_actions);
955 
956     switch (info->GetAction())
957     {
958         case FileAction::eFileActionNone:
959             error.Clear();
960             break;
961 
962         case FileAction::eFileActionClose:
963             if (info->GetFD() == -1)
964                 error.SetErrorString("invalid fd for posix_spawn_file_actions_addclose(...)");
965             else
966             {
967                 error.SetError(::posix_spawn_file_actions_addclose(file_actions, info->GetFD()), eErrorTypePOSIX);
968                 if (log && (error.Fail() || log))
969                     error.PutToLog(log, "posix_spawn_file_actions_addclose (action=%p, fd=%i)",
970                                    static_cast<void *>(file_actions), info->GetFD());
971             }
972             break;
973 
974         case FileAction::eFileActionDuplicate:
975             if (info->GetFD() == -1)
976                 error.SetErrorString("invalid fd for posix_spawn_file_actions_adddup2(...)");
977             else if (info->GetActionArgument() == -1)
978                 error.SetErrorString("invalid duplicate fd for posix_spawn_file_actions_adddup2(...)");
979             else
980             {
981                 error.SetError(
982                     ::posix_spawn_file_actions_adddup2(file_actions, info->GetFD(), info->GetActionArgument()),
983                     eErrorTypePOSIX);
984                 if (log && (error.Fail() || log))
985                     error.PutToLog(log, "posix_spawn_file_actions_adddup2 (action=%p, fd=%i, dup_fd=%i)",
986                                    static_cast<void *>(file_actions), info->GetFD(), info->GetActionArgument());
987             }
988             break;
989 
990         case FileAction::eFileActionOpen:
991             if (info->GetFD() == -1)
992                 error.SetErrorString("invalid fd in posix_spawn_file_actions_addopen(...)");
993             else
994             {
995                 int oflag = info->GetActionArgument();
996 
997                 mode_t mode = 0;
998 
999                 if (oflag & O_CREAT)
1000                     mode = 0640;
1001 
1002                 error.SetError(
1003                     ::posix_spawn_file_actions_addopen(file_actions, info->GetFD(), info->GetPath(), oflag, mode),
1004                     eErrorTypePOSIX);
1005                 if (error.Fail() || log)
1006                     error.PutToLog(log,
1007                                    "posix_spawn_file_actions_addopen (action=%p, fd=%i, path='%s', oflag=%i, mode=%i)",
1008                                    static_cast<void *>(file_actions), info->GetFD(), info->GetPath(), oflag, mode);
1009             }
1010             break;
1011     }
1012     return error.Success();
1013 }
1014 #endif // !defined(__ANDROID__) && !defined(__ANDROID_NDK__)
1015 #endif // defined (__APPLE__) || defined (__linux__) || defined (__FreeBSD__) || defined (__GLIBC__) || defined(__NetBSD__)
1016 
1017 #if defined(__linux__) || defined(__FreeBSD__) || defined(__GLIBC__) || defined(__NetBSD__) || defined(_WIN32)
1018 // The functions below implement process launching via posix_spawn() for Linux,
1019 // FreeBSD and NetBSD.
1020 
1021 Error
1022 Host::LaunchProcess (ProcessLaunchInfo &launch_info)
1023 {
1024     std::unique_ptr<ProcessLauncher> delegate_launcher;
1025 #if defined(_WIN32)
1026     delegate_launcher.reset(new ProcessLauncherWindows());
1027 #elif defined(__ANDROID__) || defined(__ANDROID_NDK__)
1028     delegate_launcher.reset(new ProcessLauncherAndroid());
1029 #else
1030     delegate_launcher.reset(new ProcessLauncherPosix());
1031 #endif
1032     MonitoringProcessLauncher launcher(std::move(delegate_launcher));
1033 
1034     Error error;
1035     HostProcess process = launcher.LaunchProcess(launch_info, error);
1036 
1037     // TODO(zturner): It would be better if the entire HostProcess were returned instead of writing
1038     // it into this structure.
1039     launch_info.SetProcessID(process.GetProcessId());
1040 
1041     return error;
1042 }
1043 #endif // defined(__linux__) || defined(__FreeBSD__) || defined(__NetBSD__)
1044 
1045 #ifndef _WIN32
1046 void
1047 Host::Kill(lldb::pid_t pid, int signo)
1048 {
1049     ::kill(pid, signo);
1050 }
1051 
1052 #endif
1053 
1054 #if !defined (__APPLE__)
1055 bool
1056 Host::OpenFileInExternalEditor (const FileSpec &file_spec, uint32_t line_no)
1057 {
1058     return false;
1059 }
1060 
1061 void
1062 Host::SetCrashDescriptionWithFormat (const char *format, ...)
1063 {
1064 }
1065 
1066 void
1067 Host::SetCrashDescription (const char *description)
1068 {
1069 }
1070 
1071 #endif
1072 
1073 const UnixSignalsSP &
1074 Host::GetUnixSignals()
1075 {
1076     static const auto s_unix_signals_sp = UnixSignals::Create(HostInfo::GetArchitecture());
1077     return s_unix_signals_sp;
1078 }
1079