xref: /llvm-project/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp (revision 0bce1b67a3074d26c53fc5eb8d8edfa66bcfff77)
1 //===-- NativeProcessLinux.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 #include "lldb/lldb-python.h"
11 
12 #include "NativeProcessLinux.h"
13 
14 // C Includes
15 #include <errno.h>
16 #include <poll.h>
17 #include <string.h>
18 #include <stdint.h>
19 #include <unistd.h>
20 #include <linux/unistd.h>
21 #include <sys/personality.h>
22 #include <sys/ptrace.h>
23 #include <sys/socket.h>
24 #include <sys/syscall.h>
25 #include <sys/types.h>
26 #include <sys/user.h>
27 #include <sys/wait.h>
28 
29 // C++ Includes
30 #include <fstream>
31 #include <string>
32 
33 // Other libraries and framework includes
34 #include "lldb/Core/Debugger.h"
35 #include "lldb/Core/Error.h"
36 #include "lldb/Core/Module.h"
37 #include "lldb/Core/RegisterValue.h"
38 #include "lldb/Core/Scalar.h"
39 #include "lldb/Core/State.h"
40 #include "lldb/Host/Host.h"
41 #include "lldb/Symbol/ObjectFile.h"
42 #include "lldb/Target/NativeRegisterContext.h"
43 #include "lldb/Target/ProcessLaunchInfo.h"
44 #include "lldb/Utility/PseudoTerminal.h"
45 
46 #include "Host/common/NativeBreakpoint.h"
47 #include "Utility/StringExtractor.h"
48 
49 #include "Plugins/Process/Utility/LinuxSignals.h"
50 #include "NativeThreadLinux.h"
51 #include "ProcFileReader.h"
52 #include "ProcessPOSIXLog.h"
53 
54 #define DEBUG_PTRACE_MAXBYTES 20
55 
56 // Support ptrace extensions even when compiled without required kernel support
57 #ifndef PT_GETREGS
58 #ifndef PTRACE_GETREGS
59   #define PTRACE_GETREGS 12
60 #endif
61 #endif
62 #ifndef PT_SETREGS
63 #ifndef PTRACE_SETREGS
64   #define PTRACE_SETREGS 13
65 #endif
66 #endif
67 #ifndef PT_GETFPREGS
68 #ifndef PTRACE_GETFPREGS
69   #define PTRACE_GETFPREGS 14
70 #endif
71 #endif
72 #ifndef PT_SETFPREGS
73 #ifndef PTRACE_SETFPREGS
74   #define PTRACE_SETFPREGS 15
75 #endif
76 #endif
77 #ifndef PTRACE_GETREGSET
78   #define PTRACE_GETREGSET 0x4204
79 #endif
80 #ifndef PTRACE_SETREGSET
81   #define PTRACE_SETREGSET 0x4205
82 #endif
83 #ifndef PTRACE_GET_THREAD_AREA
84   #define PTRACE_GET_THREAD_AREA 25
85 #endif
86 #ifndef PTRACE_ARCH_PRCTL
87   #define PTRACE_ARCH_PRCTL      30
88 #endif
89 #ifndef ARCH_GET_FS
90   #define ARCH_SET_GS 0x1001
91   #define ARCH_SET_FS 0x1002
92   #define ARCH_GET_FS 0x1003
93   #define ARCH_GET_GS 0x1004
94 #endif
95 
96 #define LLDB_PERSONALITY_GET_CURRENT_SETTINGS  0xffffffff
97 
98 // Support hardware breakpoints in case it has not been defined
99 #ifndef TRAP_HWBKPT
100   #define TRAP_HWBKPT 4
101 #endif
102 
103 // Try to define a macro to encapsulate the tgkill syscall
104 // fall back on kill() if tgkill isn't available
105 #define tgkill(pid, tid, sig)  syscall(SYS_tgkill, pid, tid, sig)
106 
107 // We disable the tracing of ptrace calls for integration builds to
108 // avoid the additional indirection and checks.
109 #ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
110 #define PTRACE(req, pid, addr, data, data_size) \
111     PtraceWrapper((req), (pid), (addr), (data), (data_size), #req, __FILE__, __LINE__)
112 #else
113 #define PTRACE(req, pid, addr, data, data_size) \
114     PtraceWrapper((req), (pid), (addr), (data), (data_size))
115 #endif
116 
117 // Private bits we only need internally.
118 namespace
119 {
120     using namespace lldb;
121     using namespace lldb_private;
122 
123     const UnixSignals&
124     GetUnixSignals ()
125     {
126         static process_linux::LinuxSignals signals;
127         return signals;
128     }
129 
130     const char *
131     GetFilePath(const lldb_private::FileAction *file_action, const char *default_path)
132     {
133         const char *pts_name = "/dev/pts/";
134         const char *path = NULL;
135 
136         if (file_action)
137         {
138             if (file_action->GetAction() == FileAction::eFileActionOpen)
139             {
140                 path = file_action->GetPath ();
141                 // By default the stdio paths passed in will be pseudo-terminal
142                 // (/dev/pts). If so, convert to using a different default path
143                 // instead to redirect I/O to the debugger console. This should
144                 //  also handle user overrides to /dev/null or a different file.
145                 if (!path || ::strncmp (path, pts_name, ::strlen (pts_name)) == 0)
146                     path = default_path;
147             }
148         }
149 
150         return path;
151     }
152 
153     Error
154     ResolveProcessArchitecture (lldb::pid_t pid, Platform &platform, ArchSpec &arch)
155     {
156         // Grab process info for the running process.
157         ProcessInstanceInfo process_info;
158         if (!platform.GetProcessInfo (pid, process_info))
159             return lldb_private::Error("failed to get process info");
160 
161         // Resolve the executable module.
162         ModuleSP exe_module_sp;
163         FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths ());
164         Error error = platform.ResolveExecutable(
165             process_info.GetExecutableFile (),
166             platform.GetSystemArchitecture (),
167             exe_module_sp,
168             executable_search_paths.GetSize () ? &executable_search_paths : NULL);
169 
170         if (!error.Success ())
171             return error;
172 
173         // Check if we've got our architecture from the exe_module.
174         arch = exe_module_sp->GetArchitecture ();
175         if (arch.IsValid ())
176             return Error();
177         else
178             return Error("failed to retrieve a valid architecture from the exe module");
179     }
180 
181     void
182     DisplayBytes (lldb_private::StreamString &s, void *bytes, uint32_t count)
183     {
184         uint8_t *ptr = (uint8_t *)bytes;
185         const uint32_t loop_count = std::min<uint32_t>(DEBUG_PTRACE_MAXBYTES, count);
186         for(uint32_t i=0; i<loop_count; i++)
187         {
188             s.Printf ("[%x]", *ptr);
189             ptr++;
190         }
191     }
192 
193     void
194     PtraceDisplayBytes(int &req, void *data, size_t data_size)
195     {
196         StreamString buf;
197         Log *verbose_log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (
198                     POSIX_LOG_PTRACE | POSIX_LOG_VERBOSE));
199 
200         if (verbose_log)
201         {
202             switch(req)
203             {
204             case PTRACE_POKETEXT:
205             {
206                 DisplayBytes(buf, &data, 8);
207                 verbose_log->Printf("PTRACE_POKETEXT %s", buf.GetData());
208                 break;
209             }
210             case PTRACE_POKEDATA:
211             {
212                 DisplayBytes(buf, &data, 8);
213                 verbose_log->Printf("PTRACE_POKEDATA %s", buf.GetData());
214                 break;
215             }
216             case PTRACE_POKEUSER:
217             {
218                 DisplayBytes(buf, &data, 8);
219                 verbose_log->Printf("PTRACE_POKEUSER %s", buf.GetData());
220                 break;
221             }
222             case PTRACE_SETREGS:
223             {
224                 DisplayBytes(buf, data, data_size);
225                 verbose_log->Printf("PTRACE_SETREGS %s", buf.GetData());
226                 break;
227             }
228             case PTRACE_SETFPREGS:
229             {
230                 DisplayBytes(buf, data, data_size);
231                 verbose_log->Printf("PTRACE_SETFPREGS %s", buf.GetData());
232                 break;
233             }
234             case PTRACE_SETSIGINFO:
235             {
236                 DisplayBytes(buf, data, sizeof(siginfo_t));
237                 verbose_log->Printf("PTRACE_SETSIGINFO %s", buf.GetData());
238                 break;
239             }
240             case PTRACE_SETREGSET:
241             {
242                 // Extract iov_base from data, which is a pointer to the struct IOVEC
243                 DisplayBytes(buf, *(void **)data, data_size);
244                 verbose_log->Printf("PTRACE_SETREGSET %s", buf.GetData());
245                 break;
246             }
247             default:
248             {
249             }
250             }
251         }
252     }
253 
254     // Wrapper for ptrace to catch errors and log calls.
255     // Note that ptrace sets errno on error because -1 can be a valid result (i.e. for PTRACE_PEEK*)
256     long
257     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size,
258             const char* reqName, const char* file, int line)
259     {
260         long int result;
261 
262         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PTRACE));
263 
264         PtraceDisplayBytes(req, data, data_size);
265 
266         errno = 0;
267         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
268             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
269         else
270             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
271 
272         if (log)
273             log->Printf("ptrace(%s, %" PRIu64 ", %p, %p, %zu)=%lX called from file %s line %d",
274                     reqName, pid, addr, data, data_size, result, file, line);
275 
276         PtraceDisplayBytes(req, data, data_size);
277 
278         if (log && errno != 0)
279         {
280             const char* str;
281             switch (errno)
282             {
283             case ESRCH:  str = "ESRCH"; break;
284             case EINVAL: str = "EINVAL"; break;
285             case EBUSY:  str = "EBUSY"; break;
286             case EPERM:  str = "EPERM"; break;
287             default:     str = "<unknown>";
288             }
289             log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
290         }
291 
292         return result;
293     }
294 
295 #ifdef LLDB_CONFIGURATION_BUILDANDINTEGRATION
296     // Wrapper for ptrace when logging is not required.
297     // Sets errno to 0 prior to calling ptrace.
298     long
299     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size)
300     {
301         long result = 0;
302         errno = 0;
303         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
304             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
305         else
306             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
307         return result;
308     }
309 #endif
310 
311     //------------------------------------------------------------------------------
312     // Static implementations of NativeProcessLinux::ReadMemory and
313     // NativeProcessLinux::WriteMemory.  This enables mutual recursion between these
314     // functions without needed to go thru the thread funnel.
315 
316     static lldb::addr_t
317     DoReadMemory (
318         lldb::pid_t pid,
319         lldb::addr_t vm_addr,
320         void *buf,
321         lldb::addr_t size,
322         Error &error)
323     {
324         // ptrace word size is determined by the host, not the child
325         static const unsigned word_size = sizeof(void*);
326         unsigned char *dst = static_cast<unsigned char*>(buf);
327         lldb::addr_t bytes_read;
328         lldb::addr_t remainder;
329         long data;
330 
331         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
332         if (log)
333             ProcessPOSIXLog::IncNestLevel();
334         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
335             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %d, %p, %p, %zd, _)", __FUNCTION__,
336                     pid, word_size, (void*)vm_addr, buf, size);
337 
338         assert(sizeof(data) >= word_size);
339         for (bytes_read = 0; bytes_read < size; bytes_read += remainder)
340         {
341             errno = 0;
342             data = PTRACE(PTRACE_PEEKDATA, pid, (void*)vm_addr, NULL, 0);
343             if (errno)
344             {
345                 error.SetErrorToErrno();
346                 if (log)
347                     ProcessPOSIXLog::DecNestLevel();
348                 return bytes_read;
349             }
350 
351             remainder = size - bytes_read;
352             remainder = remainder > word_size ? word_size : remainder;
353 
354             // Copy the data into our buffer
355             for (unsigned i = 0; i < remainder; ++i)
356                 dst[i] = ((data >> i*8) & 0xFF);
357 
358             if (log && ProcessPOSIXLog::AtTopNestLevel() &&
359                     (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
360                             (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
361                                     size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
362             {
363                 uintptr_t print_dst = 0;
364                 // Format bytes from data by moving into print_dst for log output
365                 for (unsigned i = 0; i < remainder; ++i)
366                     print_dst |= (((data >> i*8) & 0xFF) << i*8);
367                 log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
368                         (void*)vm_addr, print_dst, (unsigned long)data);
369             }
370 
371             vm_addr += word_size;
372             dst += word_size;
373         }
374 
375         if (log)
376             ProcessPOSIXLog::DecNestLevel();
377         return bytes_read;
378     }
379 
380     static lldb::addr_t
381     DoWriteMemory(
382         lldb::pid_t pid,
383         lldb::addr_t vm_addr,
384         const void *buf,
385         lldb::addr_t size,
386         Error &error)
387     {
388         // ptrace word size is determined by the host, not the child
389         static const unsigned word_size = sizeof(void*);
390         const unsigned char *src = static_cast<const unsigned char*>(buf);
391         lldb::addr_t bytes_written = 0;
392         lldb::addr_t remainder;
393 
394         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
395         if (log)
396             ProcessPOSIXLog::IncNestLevel();
397         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
398             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %u, %p, %p, %" PRIu64 ")", __FUNCTION__,
399                     pid, word_size, (void*)vm_addr, buf, size);
400 
401         for (bytes_written = 0; bytes_written < size; bytes_written += remainder)
402         {
403             remainder = size - bytes_written;
404             remainder = remainder > word_size ? word_size : remainder;
405 
406             if (remainder == word_size)
407             {
408                 unsigned long data = 0;
409                 assert(sizeof(data) >= word_size);
410                 for (unsigned i = 0; i < word_size; ++i)
411                     data |= (unsigned long)src[i] << i*8;
412 
413                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
414                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
415                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
416                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
417                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
418                             (void*)vm_addr, *(unsigned long*)src, data);
419 
420                 if (PTRACE(PTRACE_POKEDATA, pid, (void*)vm_addr, (void*)data, 0))
421                 {
422                     error.SetErrorToErrno();
423                     if (log)
424                         ProcessPOSIXLog::DecNestLevel();
425                     return bytes_written;
426                 }
427             }
428             else
429             {
430                 unsigned char buff[8];
431                 if (DoReadMemory(pid, vm_addr,
432                                 buff, word_size, error) != word_size)
433                 {
434                     if (log)
435                         ProcessPOSIXLog::DecNestLevel();
436                     return bytes_written;
437                 }
438 
439                 memcpy(buff, src, remainder);
440 
441                 if (DoWriteMemory(pid, vm_addr,
442                                 buff, word_size, error) != word_size)
443                 {
444                     if (log)
445                         ProcessPOSIXLog::DecNestLevel();
446                     return bytes_written;
447                 }
448 
449                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
450                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
451                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
452                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
453                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
454                             (void*)vm_addr, *(unsigned long*)src, *(unsigned long*)buff);
455             }
456 
457             vm_addr += word_size;
458             src += word_size;
459         }
460         if (log)
461             ProcessPOSIXLog::DecNestLevel();
462         return bytes_written;
463     }
464 
465     //------------------------------------------------------------------------------
466     /// @class Operation
467     /// @brief Represents a NativeProcessLinux operation.
468     ///
469     /// Under Linux, it is not possible to ptrace() from any other thread but the
470     /// one that spawned or attached to the process from the start.  Therefore, when
471     /// a NativeProcessLinux is asked to deliver or change the state of an inferior
472     /// process the operation must be "funneled" to a specific thread to perform the
473     /// task.  The Operation class provides an abstract base for all services the
474     /// NativeProcessLinux must perform via the single virtual function Execute, thus
475     /// encapsulating the code that needs to run in the privileged context.
476     class Operation
477     {
478     public:
479         Operation () : m_error() { }
480 
481         virtual
482         ~Operation() {}
483 
484         virtual void
485         Execute (NativeProcessLinux *process) = 0;
486 
487         const Error &
488         GetError () const { return m_error; }
489 
490     protected:
491         Error m_error;
492     };
493 
494     //------------------------------------------------------------------------------
495     /// @class ReadOperation
496     /// @brief Implements NativeProcessLinux::ReadMemory.
497     class ReadOperation : public Operation
498     {
499     public:
500         ReadOperation (
501             lldb::addr_t addr,
502             void *buff,
503             lldb::addr_t size,
504             lldb::addr_t &result) :
505             Operation (),
506             m_addr (addr),
507             m_buff (buff),
508             m_size (size),
509             m_result (result)
510             {
511             }
512 
513         void Execute (NativeProcessLinux *process) override;
514 
515     private:
516         lldb::addr_t m_addr;
517         void *m_buff;
518         lldb::addr_t m_size;
519         lldb::addr_t &m_result;
520     };
521 
522     void
523     ReadOperation::Execute (NativeProcessLinux *process)
524     {
525         m_result = DoReadMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
526     }
527 
528     //------------------------------------------------------------------------------
529     /// @class WriteOperation
530     /// @brief Implements NativeProcessLinux::WriteMemory.
531     class WriteOperation : public Operation
532     {
533     public:
534         WriteOperation (
535             lldb::addr_t addr,
536             const void *buff,
537             lldb::addr_t size,
538             lldb::addr_t &result) :
539             Operation (),
540             m_addr (addr),
541             m_buff (buff),
542             m_size (size),
543             m_result (result)
544             {
545             }
546 
547         void Execute (NativeProcessLinux *process) override;
548 
549     private:
550         lldb::addr_t m_addr;
551         const void *m_buff;
552         lldb::addr_t m_size;
553         lldb::addr_t &m_result;
554     };
555 
556     void
557     WriteOperation::Execute(NativeProcessLinux *process)
558     {
559         m_result = DoWriteMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
560     }
561 
562     //------------------------------------------------------------------------------
563     /// @class ReadRegOperation
564     /// @brief Implements NativeProcessLinux::ReadRegisterValue.
565     class ReadRegOperation : public Operation
566     {
567     public:
568         ReadRegOperation(lldb::tid_t tid, uint32_t offset, const char *reg_name,
569                 RegisterValue &value, bool &result)
570             : m_tid(tid), m_offset(static_cast<uintptr_t> (offset)), m_reg_name(reg_name),
571               m_value(value), m_result(result)
572             { }
573 
574         void Execute(NativeProcessLinux *monitor);
575 
576     private:
577         lldb::tid_t m_tid;
578         uintptr_t m_offset;
579         const char *m_reg_name;
580         RegisterValue &m_value;
581         bool &m_result;
582     };
583 
584     void
585     ReadRegOperation::Execute(NativeProcessLinux *monitor)
586     {
587         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
588 
589         // Set errno to zero so that we can detect a failed peek.
590         errno = 0;
591         lldb::addr_t data = PTRACE(PTRACE_PEEKUSER, m_tid, (void*)m_offset, NULL, 0);
592         if (errno)
593             m_result = false;
594         else
595         {
596             m_value = data;
597             m_result = true;
598         }
599         if (log)
600             log->Printf ("NativeProcessLinux::%s() reg %s: 0x%" PRIx64, __FUNCTION__,
601                     m_reg_name, data);
602     }
603 
604     //------------------------------------------------------------------------------
605     /// @class WriteRegOperation
606     /// @brief Implements NativeProcessLinux::WriteRegisterValue.
607     class WriteRegOperation : public Operation
608     {
609     public:
610         WriteRegOperation(lldb::tid_t tid, unsigned offset, const char *reg_name,
611                 const RegisterValue &value, bool &result)
612             : m_tid(tid), m_offset(offset), m_reg_name(reg_name),
613               m_value(value), m_result(result)
614             { }
615 
616         void Execute(NativeProcessLinux *monitor);
617 
618     private:
619         lldb::tid_t m_tid;
620         uintptr_t m_offset;
621         const char *m_reg_name;
622         const RegisterValue &m_value;
623         bool &m_result;
624     };
625 
626     void
627     WriteRegOperation::Execute(NativeProcessLinux *monitor)
628     {
629         void* buf;
630         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
631 
632         buf = (void*) m_value.GetAsUInt64();
633 
634         if (log)
635             log->Printf ("NativeProcessLinux::%s() reg %s: %p", __FUNCTION__, m_reg_name, buf);
636         if (PTRACE(PTRACE_POKEUSER, m_tid, (void*)m_offset, buf, 0))
637             m_result = false;
638         else
639             m_result = true;
640     }
641 
642     //------------------------------------------------------------------------------
643     /// @class ReadGPROperation
644     /// @brief Implements NativeProcessLinux::ReadGPR.
645     class ReadGPROperation : public Operation
646     {
647     public:
648         ReadGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
649             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
650             { }
651 
652         void Execute(NativeProcessLinux *monitor);
653 
654     private:
655         lldb::tid_t m_tid;
656         void *m_buf;
657         size_t m_buf_size;
658         bool &m_result;
659     };
660 
661     void
662     ReadGPROperation::Execute(NativeProcessLinux *monitor)
663     {
664         if (PTRACE(PTRACE_GETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
665             m_result = false;
666         else
667             m_result = true;
668     }
669 
670     //------------------------------------------------------------------------------
671     /// @class ReadFPROperation
672     /// @brief Implements NativeProcessLinux::ReadFPR.
673     class ReadFPROperation : public Operation
674     {
675     public:
676         ReadFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
677             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
678             { }
679 
680         void Execute(NativeProcessLinux *monitor);
681 
682     private:
683         lldb::tid_t m_tid;
684         void *m_buf;
685         size_t m_buf_size;
686         bool &m_result;
687     };
688 
689     void
690     ReadFPROperation::Execute(NativeProcessLinux *monitor)
691     {
692         if (PTRACE(PTRACE_GETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
693             m_result = false;
694         else
695             m_result = true;
696     }
697 
698     //------------------------------------------------------------------------------
699     /// @class ReadRegisterSetOperation
700     /// @brief Implements NativeProcessLinux::ReadRegisterSet.
701     class ReadRegisterSetOperation : public Operation
702     {
703     public:
704         ReadRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
705             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
706             { }
707 
708         void Execute(NativeProcessLinux *monitor);
709 
710     private:
711         lldb::tid_t m_tid;
712         void *m_buf;
713         size_t m_buf_size;
714         const unsigned int m_regset;
715         bool &m_result;
716     };
717 
718     void
719     ReadRegisterSetOperation::Execute(NativeProcessLinux *monitor)
720     {
721         if (PTRACE(PTRACE_GETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
722             m_result = false;
723         else
724             m_result = true;
725     }
726 
727     //------------------------------------------------------------------------------
728     /// @class WriteGPROperation
729     /// @brief Implements NativeProcessLinux::WriteGPR.
730     class WriteGPROperation : public Operation
731     {
732     public:
733         WriteGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
734             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
735             { }
736 
737         void Execute(NativeProcessLinux *monitor);
738 
739     private:
740         lldb::tid_t m_tid;
741         void *m_buf;
742         size_t m_buf_size;
743         bool &m_result;
744     };
745 
746     void
747     WriteGPROperation::Execute(NativeProcessLinux *monitor)
748     {
749         if (PTRACE(PTRACE_SETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
750             m_result = false;
751         else
752             m_result = true;
753     }
754 
755     //------------------------------------------------------------------------------
756     /// @class WriteFPROperation
757     /// @brief Implements NativeProcessLinux::WriteFPR.
758     class WriteFPROperation : public Operation
759     {
760     public:
761         WriteFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
762             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
763             { }
764 
765         void Execute(NativeProcessLinux *monitor);
766 
767     private:
768         lldb::tid_t m_tid;
769         void *m_buf;
770         size_t m_buf_size;
771         bool &m_result;
772     };
773 
774     void
775     WriteFPROperation::Execute(NativeProcessLinux *monitor)
776     {
777         if (PTRACE(PTRACE_SETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
778             m_result = false;
779         else
780             m_result = true;
781     }
782 
783     //------------------------------------------------------------------------------
784     /// @class WriteRegisterSetOperation
785     /// @brief Implements NativeProcessLinux::WriteRegisterSet.
786     class WriteRegisterSetOperation : public Operation
787     {
788     public:
789         WriteRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
790             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
791             { }
792 
793         void Execute(NativeProcessLinux *monitor);
794 
795     private:
796         lldb::tid_t m_tid;
797         void *m_buf;
798         size_t m_buf_size;
799         const unsigned int m_regset;
800         bool &m_result;
801     };
802 
803     void
804     WriteRegisterSetOperation::Execute(NativeProcessLinux *monitor)
805     {
806         if (PTRACE(PTRACE_SETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
807             m_result = false;
808         else
809             m_result = true;
810     }
811 
812     //------------------------------------------------------------------------------
813     /// @class ResumeOperation
814     /// @brief Implements NativeProcessLinux::Resume.
815     class ResumeOperation : public Operation
816     {
817     public:
818         ResumeOperation(lldb::tid_t tid, uint32_t signo, bool &result) :
819             m_tid(tid), m_signo(signo), m_result(result) { }
820 
821         void Execute(NativeProcessLinux *monitor);
822 
823     private:
824         lldb::tid_t m_tid;
825         uint32_t m_signo;
826         bool &m_result;
827     };
828 
829     void
830     ResumeOperation::Execute(NativeProcessLinux *monitor)
831     {
832         intptr_t data = 0;
833 
834         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
835             data = m_signo;
836 
837         if (PTRACE(PTRACE_CONT, m_tid, NULL, (void*)data, 0))
838         {
839             Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
840 
841             if (log)
842                 log->Printf ("ResumeOperation (%"  PRIu64 ") failed: %s", m_tid, strerror(errno));
843             m_result = false;
844         }
845         else
846             m_result = true;
847     }
848 
849     //------------------------------------------------------------------------------
850     /// @class SingleStepOperation
851     /// @brief Implements NativeProcessLinux::SingleStep.
852     class SingleStepOperation : public Operation
853     {
854     public:
855         SingleStepOperation(lldb::tid_t tid, uint32_t signo, bool &result)
856             : m_tid(tid), m_signo(signo), m_result(result) { }
857 
858         void Execute(NativeProcessLinux *monitor);
859 
860     private:
861         lldb::tid_t m_tid;
862         uint32_t m_signo;
863         bool &m_result;
864     };
865 
866     void
867     SingleStepOperation::Execute(NativeProcessLinux *monitor)
868     {
869         intptr_t data = 0;
870 
871         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
872             data = m_signo;
873 
874         if (PTRACE(PTRACE_SINGLESTEP, m_tid, NULL, (void*)data, 0))
875             m_result = false;
876         else
877             m_result = true;
878     }
879 
880     //------------------------------------------------------------------------------
881     /// @class SiginfoOperation
882     /// @brief Implements NativeProcessLinux::GetSignalInfo.
883     class SiginfoOperation : public Operation
884     {
885     public:
886         SiginfoOperation(lldb::tid_t tid, void *info, bool &result, int &ptrace_err)
887             : m_tid(tid), m_info(info), m_result(result), m_err(ptrace_err) { }
888 
889         void Execute(NativeProcessLinux *monitor);
890 
891     private:
892         lldb::tid_t m_tid;
893         void *m_info;
894         bool &m_result;
895         int &m_err;
896     };
897 
898     void
899     SiginfoOperation::Execute(NativeProcessLinux *monitor)
900     {
901         if (PTRACE(PTRACE_GETSIGINFO, m_tid, NULL, m_info, 0)) {
902             m_result = false;
903             m_err = errno;
904         }
905         else
906             m_result = true;
907     }
908 
909     //------------------------------------------------------------------------------
910     /// @class EventMessageOperation
911     /// @brief Implements NativeProcessLinux::GetEventMessage.
912     class EventMessageOperation : public Operation
913     {
914     public:
915         EventMessageOperation(lldb::tid_t tid, unsigned long *message, bool &result)
916             : m_tid(tid), m_message(message), m_result(result) { }
917 
918         void Execute(NativeProcessLinux *monitor);
919 
920     private:
921         lldb::tid_t m_tid;
922         unsigned long *m_message;
923         bool &m_result;
924     };
925 
926     void
927     EventMessageOperation::Execute(NativeProcessLinux *monitor)
928     {
929         if (PTRACE(PTRACE_GETEVENTMSG, m_tid, NULL, m_message, 0))
930             m_result = false;
931         else
932             m_result = true;
933     }
934 
935     class DetachOperation : public Operation
936     {
937     public:
938         DetachOperation(lldb::tid_t tid, Error &result) : m_tid(tid), m_error(result) { }
939 
940         void Execute(NativeProcessLinux *monitor);
941 
942     private:
943         lldb::tid_t m_tid;
944         Error &m_error;
945     };
946 
947     void
948     DetachOperation::Execute(NativeProcessLinux *monitor)
949     {
950         if (ptrace(PT_DETACH, m_tid, NULL, 0) < 0)
951             m_error.SetErrorToErrno();
952     }
953 
954 }
955 
956 using namespace lldb_private;
957 
958 // Simple helper function to ensure flags are enabled on the given file
959 // descriptor.
960 static bool
961 EnsureFDFlags(int fd, int flags, Error &error)
962 {
963     int status;
964 
965     if ((status = fcntl(fd, F_GETFL)) == -1)
966     {
967         error.SetErrorToErrno();
968         return false;
969     }
970 
971     if (fcntl(fd, F_SETFL, status | flags) == -1)
972     {
973         error.SetErrorToErrno();
974         return false;
975     }
976 
977     return true;
978 }
979 
980 NativeProcessLinux::OperationArgs::OperationArgs(NativeProcessLinux *monitor)
981     : m_monitor(monitor)
982 {
983     sem_init(&m_semaphore, 0, 0);
984 }
985 
986 NativeProcessLinux::OperationArgs::~OperationArgs()
987 {
988     sem_destroy(&m_semaphore);
989 }
990 
991 NativeProcessLinux::LaunchArgs::LaunchArgs(NativeProcessLinux *monitor,
992                                        lldb_private::Module *module,
993                                        char const **argv,
994                                        char const **envp,
995                                        const char *stdin_path,
996                                        const char *stdout_path,
997                                        const char *stderr_path,
998                                        const char *working_dir,
999                                        const lldb_private::ProcessLaunchInfo &launch_info)
1000     : OperationArgs(monitor),
1001       m_module(module),
1002       m_argv(argv),
1003       m_envp(envp),
1004       m_stdin_path(stdin_path),
1005       m_stdout_path(stdout_path),
1006       m_stderr_path(stderr_path),
1007       m_working_dir(working_dir),
1008       m_launch_info(launch_info)
1009 {
1010 }
1011 
1012 NativeProcessLinux::LaunchArgs::~LaunchArgs()
1013 { }
1014 
1015 NativeProcessLinux::AttachArgs::AttachArgs(NativeProcessLinux *monitor,
1016                                        lldb::pid_t pid)
1017     : OperationArgs(monitor), m_pid(pid) { }
1018 
1019 NativeProcessLinux::AttachArgs::~AttachArgs()
1020 { }
1021 
1022 // -----------------------------------------------------------------------------
1023 // Public Static Methods
1024 // -----------------------------------------------------------------------------
1025 
1026 lldb_private::Error
1027 NativeProcessLinux::LaunchProcess (
1028     lldb_private::Module *exe_module,
1029     lldb_private::ProcessLaunchInfo &launch_info,
1030     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1031     NativeProcessProtocolSP &native_process_sp)
1032 {
1033     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1034 
1035     Error error;
1036 
1037     // Verify the working directory is valid if one was specified.
1038     const char* working_dir = launch_info.GetWorkingDirectory ();
1039     if (working_dir)
1040     {
1041       FileSpec working_dir_fs (working_dir, true);
1042       if (!working_dir_fs || working_dir_fs.GetFileType () != FileSpec::eFileTypeDirectory)
1043       {
1044           error.SetErrorStringWithFormat ("No such file or directory: %s", working_dir);
1045           return error;
1046       }
1047     }
1048 
1049     const lldb_private::FileAction *file_action;
1050 
1051     // Default of NULL will mean to use existing open file descriptors.
1052     const char *stdin_path = NULL;
1053     const char *stdout_path = NULL;
1054     const char *stderr_path = NULL;
1055 
1056     file_action = launch_info.GetFileActionForFD (STDIN_FILENO);
1057     stdin_path = GetFilePath (file_action, stdin_path);
1058 
1059     file_action = launch_info.GetFileActionForFD (STDOUT_FILENO);
1060     stdout_path = GetFilePath (file_action, stdout_path);
1061 
1062     file_action = launch_info.GetFileActionForFD (STDERR_FILENO);
1063     stderr_path = GetFilePath (file_action, stderr_path);
1064 
1065     // Create the NativeProcessLinux in launch mode.
1066     native_process_sp.reset (new NativeProcessLinux ());
1067 
1068     if (log)
1069     {
1070         int i = 0;
1071         for (const char **args = launch_info.GetArguments ().GetConstArgumentVector (); *args; ++args, ++i)
1072         {
1073             log->Printf ("NativeProcessLinux::%s arg %d: \"%s\"", __FUNCTION__, i, *args ? *args : "nullptr");
1074             ++i;
1075         }
1076     }
1077 
1078     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1079     {
1080         native_process_sp.reset ();
1081         error.SetErrorStringWithFormat ("failed to register the native delegate");
1082         return error;
1083     }
1084 
1085     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->LaunchInferior (
1086             exe_module,
1087             launch_info.GetArguments ().GetConstArgumentVector (),
1088             launch_info.GetEnvironmentEntries ().GetConstArgumentVector (),
1089             stdin_path,
1090             stdout_path,
1091             stderr_path,
1092             working_dir,
1093             launch_info,
1094             error);
1095 
1096     if (error.Fail ())
1097     {
1098         native_process_sp.reset ();
1099         if (log)
1100             log->Printf ("NativeProcessLinux::%s failed to launch process: %s", __FUNCTION__, error.AsCString ());
1101         return error;
1102     }
1103 
1104     launch_info.SetProcessID (native_process_sp->GetID ());
1105 
1106     return error;
1107 }
1108 
1109 lldb_private::Error
1110 NativeProcessLinux::AttachToProcess (
1111     lldb::pid_t pid,
1112     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1113     NativeProcessProtocolSP &native_process_sp)
1114 {
1115     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1116     if (log && log->GetMask ().Test (POSIX_LOG_VERBOSE))
1117         log->Printf ("NativeProcessLinux::%s(pid = %" PRIi64 ")", __FUNCTION__, pid);
1118 
1119     // Grab the current platform architecture.  This should be Linux,
1120     // since this code is only intended to run on a Linux host.
1121     PlatformSP platform_sp (Platform::GetDefaultPlatform ());
1122     if (!platform_sp)
1123         return Error("failed to get a valid default platform");
1124 
1125     // Retrieve the architecture for the running process.
1126     ArchSpec process_arch;
1127     Error error = ResolveProcessArchitecture (pid, *platform_sp.get (), process_arch);
1128     if (!error.Success ())
1129         return error;
1130 
1131     native_process_sp.reset (new NativeProcessLinux ());
1132 
1133     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1134     {
1135         native_process_sp.reset (new NativeProcessLinux ());
1136         error.SetErrorStringWithFormat ("failed to register the native delegate");
1137         return error;
1138     }
1139 
1140     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->AttachToInferior (pid, error);
1141     if (!error.Success ())
1142     {
1143         native_process_sp.reset ();
1144         return error;
1145     }
1146 
1147     return error;
1148 }
1149 
1150 // -----------------------------------------------------------------------------
1151 // Public Instance Methods
1152 // -----------------------------------------------------------------------------
1153 
1154 NativeProcessLinux::NativeProcessLinux () :
1155     NativeProcessProtocol (LLDB_INVALID_PROCESS_ID),
1156     m_arch (),
1157     m_operation_thread (LLDB_INVALID_HOST_THREAD),
1158     m_monitor_thread (LLDB_INVALID_HOST_THREAD),
1159     m_operation (nullptr),
1160     m_operation_mutex (),
1161     m_operation_pending (),
1162     m_operation_done (),
1163     m_wait_for_stop_tids (),
1164     m_wait_for_stop_tids_mutex (),
1165     m_supports_mem_region (eLazyBoolCalculate),
1166     m_mem_region_cache (),
1167     m_mem_region_cache_mutex ()
1168 {
1169 }
1170 
1171 //------------------------------------------------------------------------------
1172 /// The basic design of the NativeProcessLinux is built around two threads.
1173 ///
1174 /// One thread (@see SignalThread) simply blocks on a call to waitpid() looking
1175 /// for changes in the debugee state.  When a change is detected a
1176 /// ProcessMessage is sent to the associated ProcessLinux instance.  This thread
1177 /// "drives" state changes in the debugger.
1178 ///
1179 /// The second thread (@see OperationThread) is responsible for two things 1)
1180 /// launching or attaching to the inferior process, and then 2) servicing
1181 /// operations such as register reads/writes, stepping, etc.  See the comments
1182 /// on the Operation class for more info as to why this is needed.
1183 void
1184 NativeProcessLinux::LaunchInferior (
1185     Module *module,
1186     const char *argv[],
1187     const char *envp[],
1188     const char *stdin_path,
1189     const char *stdout_path,
1190     const char *stderr_path,
1191     const char *working_dir,
1192     const lldb_private::ProcessLaunchInfo &launch_info,
1193     lldb_private::Error &error)
1194 {
1195     if (module)
1196         m_arch = module->GetArchitecture ();
1197 
1198     SetState(eStateLaunching);
1199 
1200     std::unique_ptr<LaunchArgs> args(
1201         new LaunchArgs(
1202             this, module, argv, envp,
1203             stdin_path, stdout_path, stderr_path,
1204             working_dir, launch_info));
1205 
1206     sem_init(&m_operation_pending, 0, 0);
1207     sem_init(&m_operation_done, 0, 0);
1208 
1209     StartLaunchOpThread(args.get(), error);
1210     if (!error.Success())
1211         return;
1212 
1213 WAIT_AGAIN:
1214     // Wait for the operation thread to initialize.
1215     if (sem_wait(&args->m_semaphore))
1216     {
1217         if (errno == EINTR)
1218             goto WAIT_AGAIN;
1219         else
1220         {
1221             error.SetErrorToErrno();
1222             return;
1223         }
1224     }
1225 
1226     // Check that the launch was a success.
1227     if (!args->m_error.Success())
1228     {
1229         StopOpThread();
1230         error = args->m_error;
1231         return;
1232     }
1233 
1234     // Finally, start monitoring the child process for change in state.
1235     m_monitor_thread = Host::StartMonitoringChildProcess(
1236         NativeProcessLinux::MonitorCallback, this, GetID(), true);
1237     if (!IS_VALID_LLDB_HOST_THREAD(m_monitor_thread))
1238     {
1239         error.SetErrorToGenericError();
1240         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1241         return;
1242     }
1243 }
1244 
1245 void
1246 NativeProcessLinux::AttachToInferior (lldb::pid_t pid, lldb_private::Error &error)
1247 {
1248     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1249     if (log)
1250         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ")", __FUNCTION__, pid);
1251 
1252     // We can use the Host for everything except the ResolveExecutable portion.
1253     PlatformSP platform_sp = Platform::GetDefaultPlatform ();
1254     if (!platform_sp)
1255     {
1256         if (log)
1257             log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 "): no default platform set", __FUNCTION__, pid);
1258         error.SetErrorString ("no default platform available");
1259     }
1260 
1261     // Gather info about the process.
1262     ProcessInstanceInfo process_info;
1263     platform_sp->GetProcessInfo (pid, process_info);
1264 
1265     // Resolve the executable module
1266     ModuleSP exe_module_sp;
1267     FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths());
1268 
1269     error = platform_sp->ResolveExecutable(process_info.GetExecutableFile(),
1270                                     Host::GetArchitecture(),
1271                                     exe_module_sp,
1272                                     executable_search_paths.GetSize() ? &executable_search_paths : NULL);
1273     if (!error.Success())
1274         return;
1275 
1276     // Set the architecture to the exe architecture.
1277     m_arch = exe_module_sp->GetArchitecture();
1278     if (log)
1279         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ") detected architecture %s", __FUNCTION__, pid, m_arch.GetArchitectureName ());
1280 
1281     m_pid = pid;
1282     SetState(eStateAttaching);
1283 
1284     sem_init (&m_operation_pending, 0, 0);
1285     sem_init (&m_operation_done, 0, 0);
1286 
1287     std::unique_ptr<AttachArgs> args (new AttachArgs (this, pid));
1288 
1289     StartAttachOpThread(args.get (), error);
1290     if (!error.Success ())
1291         return;
1292 
1293 WAIT_AGAIN:
1294     // Wait for the operation thread to initialize.
1295     if (sem_wait (&args->m_semaphore))
1296     {
1297         if (errno == EINTR)
1298             goto WAIT_AGAIN;
1299         else
1300         {
1301             error.SetErrorToErrno ();
1302             return;
1303         }
1304     }
1305 
1306     // Check that the attach was a success.
1307     if (!args->m_error.Success ())
1308     {
1309         StopOpThread ();
1310         error = args->m_error;
1311         return;
1312     }
1313 
1314     // Finally, start monitoring the child process for change in state.
1315     m_monitor_thread = Host::StartMonitoringChildProcess (
1316         NativeProcessLinux::MonitorCallback, this, GetID (), true);
1317     if (!IS_VALID_LLDB_HOST_THREAD (m_monitor_thread))
1318     {
1319         error.SetErrorToGenericError ();
1320         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1321         return;
1322     }
1323 }
1324 
1325 NativeProcessLinux::~NativeProcessLinux()
1326 {
1327     StopMonitor();
1328 }
1329 
1330 //------------------------------------------------------------------------------
1331 // Thread setup and tear down.
1332 
1333 void
1334 NativeProcessLinux::StartLaunchOpThread(LaunchArgs *args, Error &error)
1335 {
1336     static const char *g_thread_name = "lldb.process.nativelinux.operation";
1337 
1338     if (IS_VALID_LLDB_HOST_THREAD (m_operation_thread))
1339         return;
1340 
1341     m_operation_thread =
1342         Host::ThreadCreate (g_thread_name, LaunchOpThread, args, &error);
1343 }
1344 
1345 void *
1346 NativeProcessLinux::LaunchOpThread(void *arg)
1347 {
1348     LaunchArgs *args = static_cast<LaunchArgs*>(arg);
1349 
1350     if (!Launch(args)) {
1351         sem_post(&args->m_semaphore);
1352         return NULL;
1353     }
1354 
1355     ServeOperation(args);
1356     return NULL;
1357 }
1358 
1359 bool
1360 NativeProcessLinux::Launch(LaunchArgs *args)
1361 {
1362     assert (args && "null args");
1363     if (!args)
1364         return false;
1365 
1366     NativeProcessLinux *monitor = args->m_monitor;
1367     assert (monitor && "monitor is NULL");
1368     if (!monitor)
1369         return false;
1370 
1371     const char **argv = args->m_argv;
1372     const char **envp = args->m_envp;
1373     const char *stdin_path = args->m_stdin_path;
1374     const char *stdout_path = args->m_stdout_path;
1375     const char *stderr_path = args->m_stderr_path;
1376     const char *working_dir = args->m_working_dir;
1377 
1378     lldb_utility::PseudoTerminal terminal;
1379     const size_t err_len = 1024;
1380     char err_str[err_len];
1381     lldb::pid_t pid;
1382     NativeThreadProtocolSP thread_sp;
1383 
1384     lldb::ThreadSP inferior;
1385     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1386 
1387     // Propagate the environment if one is not supplied.
1388     if (envp == NULL || envp[0] == NULL)
1389         envp = const_cast<const char **>(environ);
1390 
1391     if ((pid = terminal.Fork(err_str, err_len)) == static_cast<lldb::pid_t> (-1))
1392     {
1393         args->m_error.SetErrorToGenericError();
1394         args->m_error.SetErrorString("Process fork failed.");
1395         goto FINISH;
1396     }
1397 
1398     // Recognized child exit status codes.
1399     enum {
1400         ePtraceFailed = 1,
1401         eDupStdinFailed,
1402         eDupStdoutFailed,
1403         eDupStderrFailed,
1404         eChdirFailed,
1405         eExecFailed,
1406         eSetGidFailed
1407     };
1408 
1409     // Child process.
1410     if (pid == 0)
1411     {
1412         if (log)
1413             log->Printf ("NativeProcessLinux::%s inferior process preparing to fork", __FUNCTION__);
1414 
1415         // Trace this process.
1416         if (log)
1417             log->Printf ("NativeProcessLinux::%s inferior process issuing PTRACE_TRACEME", __FUNCTION__);
1418 
1419         if (PTRACE(PTRACE_TRACEME, 0, NULL, NULL, 0) < 0)
1420         {
1421             if (log)
1422                 log->Printf ("NativeProcessLinux::%s inferior process PTRACE_TRACEME failed", __FUNCTION__);
1423             exit(ePtraceFailed);
1424         }
1425 
1426         // Do not inherit setgid powers.
1427         if (log)
1428             log->Printf ("NativeProcessLinux::%s inferior process resetting gid", __FUNCTION__);
1429 
1430         if (setgid(getgid()) != 0)
1431         {
1432             if (log)
1433                 log->Printf ("NativeProcessLinux::%s inferior process setgid() failed", __FUNCTION__);
1434             exit(eSetGidFailed);
1435         }
1436 
1437         // Attempt to have our own process group.
1438         // TODO verify if we really want this.
1439         if (log)
1440             log->Printf ("NativeProcessLinux::%s inferior process resetting process group", __FUNCTION__);
1441 
1442         if (setpgid(0, 0) != 0)
1443         {
1444             if (log)
1445             {
1446                 const int error_code = errno;
1447                 log->Printf ("NativeProcessLinux::%s inferior setpgid() failed, errno=%d (%s), continuing with existing proccess group %" PRIu64,
1448                         __FUNCTION__,
1449                         error_code,
1450                         strerror (error_code),
1451                         static_cast<lldb::pid_t> (getpgid (0)));
1452             }
1453             // Don't allow this to prevent an inferior exec.
1454         }
1455 
1456         // Dup file descriptors if needed.
1457         //
1458         // FIXME: If two or more of the paths are the same we needlessly open
1459         // the same file multiple times.
1460         if (stdin_path != NULL && stdin_path[0])
1461             if (!DupDescriptor(stdin_path, STDIN_FILENO, O_RDONLY))
1462                 exit(eDupStdinFailed);
1463 
1464         if (stdout_path != NULL && stdout_path[0])
1465             if (!DupDescriptor(stdout_path, STDOUT_FILENO, O_WRONLY | O_CREAT))
1466                 exit(eDupStdoutFailed);
1467 
1468         if (stderr_path != NULL && stderr_path[0])
1469             if (!DupDescriptor(stderr_path, STDERR_FILENO, O_WRONLY | O_CREAT))
1470                 exit(eDupStderrFailed);
1471 
1472         // Change working directory
1473         if (working_dir != NULL && working_dir[0])
1474           if (0 != ::chdir(working_dir))
1475               exit(eChdirFailed);
1476 
1477         // Disable ASLR if requested.
1478         if (args->m_launch_info.GetFlags ().Test (lldb::eLaunchFlagDisableASLR))
1479         {
1480             const int old_personality = personality (LLDB_PERSONALITY_GET_CURRENT_SETTINGS);
1481             if (old_personality == -1)
1482             {
1483                 if (log)
1484                     log->Printf ("NativeProcessLinux::%s retrieval of Linux personality () failed: %s. Cannot disable ASLR.", __FUNCTION__, strerror (errno));
1485             }
1486             else
1487             {
1488                 const int new_personality = personality (ADDR_NO_RANDOMIZE | old_personality);
1489                 if (new_personality == -1)
1490                 {
1491                     if (log)
1492                         log->Printf ("NativeProcessLinux::%s setting of Linux personality () to disable ASLR failed, ignoring: %s", __FUNCTION__, strerror (errno));
1493 
1494                 }
1495                 else
1496                 {
1497                     if (log)
1498                         log->Printf ("NativeProcessLinux::%s disbling ASLR: SUCCESS", __FUNCTION__);
1499 
1500                 }
1501             }
1502         }
1503 
1504         // Execute.  We should never return.
1505         execve(argv[0],
1506                const_cast<char *const *>(argv),
1507                const_cast<char *const *>(envp));
1508         exit(eExecFailed);
1509     }
1510 
1511     // Wait for the child process to trap on its call to execve.
1512     ::pid_t wpid;
1513     int status;
1514     if ((wpid = waitpid(pid, &status, 0)) < 0)
1515     {
1516         args->m_error.SetErrorToErrno();
1517 
1518         if (log)
1519             log->Printf ("NativeProcessLinux::%s waitpid for inferior failed with %s", __FUNCTION__, args->m_error.AsCString ());
1520 
1521         // Mark the inferior as invalid.
1522         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1523         monitor->SetState (StateType::eStateInvalid);
1524 
1525         goto FINISH;
1526     }
1527     else if (WIFEXITED(status))
1528     {
1529         // open, dup or execve likely failed for some reason.
1530         args->m_error.SetErrorToGenericError();
1531         switch (WEXITSTATUS(status))
1532         {
1533             case ePtraceFailed:
1534                 args->m_error.SetErrorString("Child ptrace failed.");
1535                 break;
1536             case eDupStdinFailed:
1537                 args->m_error.SetErrorString("Child open stdin failed.");
1538                 break;
1539             case eDupStdoutFailed:
1540                 args->m_error.SetErrorString("Child open stdout failed.");
1541                 break;
1542             case eDupStderrFailed:
1543                 args->m_error.SetErrorString("Child open stderr failed.");
1544                 break;
1545             case eChdirFailed:
1546                 args->m_error.SetErrorString("Child failed to set working directory.");
1547                 break;
1548             case eExecFailed:
1549                 args->m_error.SetErrorString("Child exec failed.");
1550                 break;
1551             case eSetGidFailed:
1552                 args->m_error.SetErrorString("Child setgid failed.");
1553                 break;
1554             default:
1555                 args->m_error.SetErrorString("Child returned unknown exit status.");
1556                 break;
1557         }
1558 
1559         if (log)
1560         {
1561             log->Printf ("NativeProcessLinux::%s inferior exited with status %d before issuing a STOP",
1562                     __FUNCTION__,
1563                     WEXITSTATUS(status));
1564         }
1565 
1566         // Mark the inferior as invalid.
1567         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1568         monitor->SetState (StateType::eStateInvalid);
1569 
1570         goto FINISH;
1571     }
1572     assert(WIFSTOPPED(status) && (wpid == static_cast< ::pid_t> (pid)) &&
1573            "Could not sync with inferior process.");
1574 
1575     if (log)
1576         log->Printf ("NativeProcessLinux::%s inferior started, now in stopped state", __FUNCTION__);
1577 
1578     if (!SetDefaultPtraceOpts(pid))
1579     {
1580         args->m_error.SetErrorToErrno();
1581         if (log)
1582             log->Printf ("NativeProcessLinux::%s inferior failed to set default ptrace options: %s",
1583                     __FUNCTION__,
1584                     args->m_error.AsCString ());
1585 
1586         // Mark the inferior as invalid.
1587         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1588         monitor->SetState (StateType::eStateInvalid);
1589 
1590         goto FINISH;
1591     }
1592 
1593     // Release the master terminal descriptor and pass it off to the
1594     // NativeProcessLinux instance.  Similarly stash the inferior pid.
1595     monitor->m_terminal_fd = terminal.ReleaseMasterFileDescriptor();
1596     monitor->m_pid = pid;
1597 
1598     // Set the terminal fd to be in non blocking mode (it simplifies the
1599     // implementation of ProcessLinux::GetSTDOUT to have a non-blocking
1600     // descriptor to read from).
1601     if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
1602     {
1603         if (log)
1604             log->Printf ("NativeProcessLinux::%s inferior EnsureFDFlags failed for ensuring terminal O_NONBLOCK setting: %s",
1605                     __FUNCTION__,
1606                     args->m_error.AsCString ());
1607 
1608         // Mark the inferior as invalid.
1609         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1610         monitor->SetState (StateType::eStateInvalid);
1611 
1612         goto FINISH;
1613     }
1614 
1615     if (log)
1616         log->Printf ("NativeProcessLinux::%s() adding pid = %" PRIu64, __FUNCTION__, pid);
1617 
1618     thread_sp = monitor->AddThread (static_cast<lldb::tid_t> (pid));
1619     assert (thread_sp && "AddThread() returned a nullptr thread");
1620     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1621     monitor->SetCurrentThreadID (thread_sp->GetID ());
1622 
1623     // Let our process instance know the thread has stopped.
1624     monitor->SetState (StateType::eStateStopped);
1625 
1626 FINISH:
1627     if (log)
1628     {
1629         if (args->m_error.Success ())
1630         {
1631             log->Printf ("NativeProcessLinux::%s inferior launching succeeded", __FUNCTION__);
1632         }
1633         else
1634         {
1635             log->Printf ("NativeProcessLinux::%s inferior launching failed: %s",
1636                 __FUNCTION__,
1637                 args->m_error.AsCString ());
1638         }
1639     }
1640     return args->m_error.Success();
1641 }
1642 
1643 void
1644 NativeProcessLinux::StartAttachOpThread(AttachArgs *args, lldb_private::Error &error)
1645 {
1646     static const char *g_thread_name = "lldb.process.linux.operation";
1647 
1648     if (IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
1649         return;
1650 
1651     m_operation_thread =
1652         Host::ThreadCreate(g_thread_name, AttachOpThread, args, &error);
1653 }
1654 
1655 void *
1656 NativeProcessLinux::AttachOpThread(void *arg)
1657 {
1658     AttachArgs *args = static_cast<AttachArgs*>(arg);
1659 
1660     if (!Attach(args)) {
1661         sem_post(&args->m_semaphore);
1662         return NULL;
1663     }
1664 
1665     ServeOperation(args);
1666     return NULL;
1667 }
1668 
1669 bool
1670 NativeProcessLinux::Attach(AttachArgs *args)
1671 {
1672     lldb::pid_t pid = args->m_pid;
1673 
1674     NativeProcessLinux *monitor = args->m_monitor;
1675     lldb::ThreadSP inferior;
1676     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1677 
1678     // Use a map to keep track of the threads which we have attached/need to attach.
1679     Host::TidMap tids_to_attach;
1680     if (pid <= 1)
1681     {
1682         args->m_error.SetErrorToGenericError();
1683         args->m_error.SetErrorString("Attaching to process 1 is not allowed.");
1684         goto FINISH;
1685     }
1686 
1687     while (Host::FindProcessThreads(pid, tids_to_attach))
1688     {
1689         for (Host::TidMap::iterator it = tids_to_attach.begin();
1690              it != tids_to_attach.end();)
1691         {
1692             if (it->second == false)
1693             {
1694                 lldb::tid_t tid = it->first;
1695 
1696                 // Attach to the requested process.
1697                 // An attach will cause the thread to stop with a SIGSTOP.
1698                 if (PTRACE(PTRACE_ATTACH, tid, NULL, NULL, 0) < 0)
1699                 {
1700                     // No such thread. The thread may have exited.
1701                     // More error handling may be needed.
1702                     if (errno == ESRCH)
1703                     {
1704                         it = tids_to_attach.erase(it);
1705                         continue;
1706                     }
1707                     else
1708                     {
1709                         args->m_error.SetErrorToErrno();
1710                         goto FINISH;
1711                     }
1712                 }
1713 
1714                 int status;
1715                 // Need to use __WALL otherwise we receive an error with errno=ECHLD
1716                 // At this point we should have a thread stopped if waitpid succeeds.
1717                 if ((status = waitpid(tid, NULL, __WALL)) < 0)
1718                 {
1719                     // No such thread. The thread may have exited.
1720                     // More error handling may be needed.
1721                     if (errno == ESRCH)
1722                     {
1723                         it = tids_to_attach.erase(it);
1724                         continue;
1725                     }
1726                     else
1727                     {
1728                         args->m_error.SetErrorToErrno();
1729                         goto FINISH;
1730                     }
1731                 }
1732 
1733                 if (!SetDefaultPtraceOpts(tid))
1734                 {
1735                     args->m_error.SetErrorToErrno();
1736                     goto FINISH;
1737                 }
1738 
1739 
1740                 if (log)
1741                     log->Printf ("NativeProcessLinux::%s() adding tid = %" PRIu64, __FUNCTION__, tid);
1742 
1743                 it->second = true;
1744 
1745                 // Create the thread, mark it as stopped.
1746                 NativeThreadProtocolSP thread_sp (monitor->AddThread (static_cast<lldb::tid_t> (tid)));
1747                 assert (thread_sp && "AddThread() returned a nullptr");
1748                 reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1749                 monitor->SetCurrentThreadID (thread_sp->GetID ());
1750             }
1751 
1752             // move the loop forward
1753             ++it;
1754         }
1755     }
1756 
1757     if (tids_to_attach.size() > 0)
1758     {
1759         monitor->m_pid = pid;
1760         // Let our process instance know the thread has stopped.
1761         monitor->SetState (StateType::eStateStopped);
1762     }
1763     else
1764     {
1765         args->m_error.SetErrorToGenericError();
1766         args->m_error.SetErrorString("No such process.");
1767     }
1768 
1769  FINISH:
1770     return args->m_error.Success();
1771 }
1772 
1773 bool
1774 NativeProcessLinux::SetDefaultPtraceOpts(lldb::pid_t pid)
1775 {
1776     long ptrace_opts = 0;
1777 
1778     // Have the child raise an event on exit.  This is used to keep the child in
1779     // limbo until it is destroyed.
1780     ptrace_opts |= PTRACE_O_TRACEEXIT;
1781 
1782     // Have the tracer trace threads which spawn in the inferior process.
1783     // TODO: if we want to support tracing the inferiors' child, add the
1784     // appropriate ptrace flags here (PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
1785     ptrace_opts |= PTRACE_O_TRACECLONE;
1786 
1787     // Have the tracer notify us before execve returns
1788     // (needed to disable legacy SIGTRAP generation)
1789     ptrace_opts |= PTRACE_O_TRACEEXEC;
1790 
1791     return PTRACE(PTRACE_SETOPTIONS, pid, NULL, (void*)ptrace_opts, 0) >= 0;
1792 }
1793 
1794 static ExitType convert_pid_status_to_exit_type (int status)
1795 {
1796     if (WIFEXITED (status))
1797         return ExitType::eExitTypeExit;
1798     else if (WIFSIGNALED (status))
1799         return ExitType::eExitTypeSignal;
1800     else if (WIFSTOPPED (status))
1801         return ExitType::eExitTypeStop;
1802     else
1803     {
1804         // We don't know what this is.
1805         return ExitType::eExitTypeInvalid;
1806     }
1807 }
1808 
1809 static int convert_pid_status_to_return_code (int status)
1810 {
1811     if (WIFEXITED (status))
1812         return WEXITSTATUS (status);
1813     else if (WIFSIGNALED (status))
1814         return WTERMSIG (status);
1815     else if (WIFSTOPPED (status))
1816         return WSTOPSIG (status);
1817     else
1818     {
1819         // We don't know what this is.
1820         return ExitType::eExitTypeInvalid;
1821     }
1822 }
1823 
1824 // Main process monitoring waitpid-loop handler.
1825 bool
1826 NativeProcessLinux::MonitorCallback(void *callback_baton,
1827                                 lldb::pid_t pid,
1828                                 bool exited,
1829                                 int signal,
1830                                 int status)
1831 {
1832     Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_PROCESS));
1833 
1834     NativeProcessLinux *const process = static_cast<NativeProcessLinux*>(callback_baton);
1835     assert (process && "process is null");
1836     if (!process)
1837     {
1838         if (log)
1839             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " callback_baton was null, can't determine process to use", __FUNCTION__, pid);
1840         return true;
1841     }
1842 
1843     // Certain activities differ based on whether the pid is the tid of the main thread.
1844     const bool is_main_thread = (pid == process->GetID ());
1845 
1846     // Assume we keep monitoring by default.
1847     bool stop_monitoring = false;
1848 
1849     // Handle when the thread exits.
1850     if (exited)
1851     {
1852         if (log)
1853             log->Printf ("NativeProcessLinux::%s() got exit signal, tid = %"  PRIu64 " (%s main thread)", __FUNCTION__, pid, is_main_thread ? "is" : "is not");
1854 
1855         // This is a thread that exited.  Ensure we're not tracking it anymore.
1856         const bool thread_found = process->StopTrackingThread (pid);
1857 
1858         if (is_main_thread)
1859         {
1860             // We only set the exit status and notify the delegate if we haven't already set the process
1861             // state to an exited state.  We normally should have received a SIGTRAP | (PTRACE_EVENT_EXIT << 8)
1862             // for the main thread.
1863             const bool already_notified = (process->GetState() == StateType::eStateExited) | (process->GetState () == StateType::eStateCrashed);
1864             if (!already_notified)
1865             {
1866                 if (log)
1867                     log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " handling main thread exit (%s), expected exit state already set but state was %s instead, setting exit state now", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found", StateAsCString (process->GetState ()));
1868                 // The main thread exited.  We're done monitoring.  Report to delegate.
1869                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
1870 
1871                 // Notify delegate that our process has exited.
1872                 process->SetState (StateType::eStateExited, true);
1873             }
1874             else
1875             {
1876                 if (log)
1877                     log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " main thread now exited (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
1878             }
1879             return true;
1880         }
1881         else
1882         {
1883             // Do we want to report to the delegate in this case?  I think not.  If this was an orderly
1884             // thread exit, we would already have received the SIGTRAP | (PTRACE_EVENT_EXIT << 8) signal,
1885             // and we would have done an all-stop then.
1886             if (log)
1887                 log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " handling non-main thread exit (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
1888 
1889             // Not the main thread, we keep going.
1890             return false;
1891         }
1892     }
1893 
1894     // Get details on the signal raised.
1895     siginfo_t info;
1896     int ptrace_err = 0;
1897 
1898     if (!process->GetSignalInfo (pid, &info, ptrace_err))
1899     {
1900         if (ptrace_err == EINVAL)
1901         {
1902             // This is the first part of the Linux ptrace group-stop mechanism.
1903             // The tracer (i.e. NativeProcessLinux) is expected to inject the signal
1904             // into the tracee (i.e. inferior) at this point.
1905             if (log)
1906                 log->Printf ("NativeProcessLinux::%s() resuming from group-stop", __FUNCTION__);
1907 
1908             // The inferior process is in 'group-stop', so deliver the stopping signal.
1909             const bool signal_delivered = process->Resume (pid, info.si_signo);
1910             if (log)
1911                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " group-stop signal delivery of signal 0x%x (%s) - %s", __FUNCTION__, pid, info.si_signo, GetUnixSignals ().GetSignalAsCString (info.si_signo), signal_delivered ? "success" : "failed");
1912 
1913             assert(signal_delivered && "SIGSTOP delivery failed while in 'group-stop' state");
1914 
1915             stop_monitoring = false;
1916         }
1917         else
1918         {
1919             // ptrace(GETSIGINFO) failed (but not due to group-stop).
1920 
1921             // A return value of ESRCH means the thread/process is no longer on the system,
1922             // so it was killed somehow outside of our control.  Either way, we can't do anything
1923             // with it anymore.
1924 
1925             // We stop monitoring if it was the main thread.
1926             stop_monitoring = is_main_thread;
1927 
1928             // Stop tracking the metadata for the thread since it's entirely off the system now.
1929             const bool thread_found = process->StopTrackingThread (pid);
1930 
1931             if (log)
1932                 log->Printf ("NativeProcessLinux::%s GetSignalInfo failed: %s, tid = %" PRIu64 ", signal = %d, status = %d (%s, %s, %s)",
1933                              __FUNCTION__, strerror(ptrace_err), pid, signal, status, ptrace_err == ESRCH ? "thread/process killed" : "unknown reason", is_main_thread ? "is main thread" : "is not main thread", thread_found ? "thread metadata removed" : "thread metadata not found");
1934 
1935             if (is_main_thread)
1936             {
1937                 // Notify the delegate - our process is not available but appears to have been killed outside
1938                 // our control.  Is eStateExited the right exit state in this case?
1939                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
1940                 process->SetState (StateType::eStateExited, true);
1941             }
1942             else
1943             {
1944                 // This thread was pulled out from underneath us.  Anything to do here? Do we want to do an all stop?
1945                 if (log)
1946                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " non-main thread exit occurred, didn't tell delegate anything since thread disappeared out from underneath us", __FUNCTION__, process->GetID (), pid);
1947             }
1948         }
1949     }
1950     else
1951     {
1952         // We have retrieved the signal info.  Dispatch appropriately.
1953         if (info.si_signo == SIGTRAP)
1954             process->MonitorSIGTRAP(&info, pid);
1955         else
1956             process->MonitorSignal(&info, pid, exited);
1957 
1958         stop_monitoring = false;
1959     }
1960 
1961     return stop_monitoring;
1962 }
1963 
1964 void
1965 NativeProcessLinux::MonitorSIGTRAP(const siginfo_t *info, lldb::pid_t pid)
1966 {
1967     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1968     const bool is_main_thread = (pid == GetID ());
1969 
1970     assert(info && info->si_signo == SIGTRAP && "Unexpected child signal!");
1971     if (!info)
1972         return;
1973 
1974     // See if we can find a thread for this signal.
1975     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
1976     if (!thread_sp)
1977     {
1978         if (log)
1979             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
1980     }
1981 
1982     switch (info->si_code)
1983     {
1984     // TODO: these two cases are required if we want to support tracing of the inferiors' children.  We'd need this to debug a monitor.
1985     // case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):
1986     // case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):
1987 
1988     case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)):
1989     {
1990         lldb::tid_t tid = LLDB_INVALID_THREAD_ID;
1991 
1992         unsigned long event_message = 0;
1993         if (GetEventMessage(pid, &event_message))
1994             tid = static_cast<lldb::tid_t> (event_message);
1995 
1996         if (log)
1997             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " received thread creation event for tid %" PRIu64, __FUNCTION__, pid, tid);
1998 
1999         // If we don't track the thread yet: create it, mark as stopped.
2000         // If we do track it, this is the wait we needed.  Now resume the new thread.
2001         // In all cases, resume the current (i.e. main process) thread.
2002         bool already_tracked = false;
2003         thread_sp = GetOrCreateThread (tid, already_tracked);
2004         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2005 
2006         // If the thread was already tracked, it means the created thread already received its SI_USER notification of creation.
2007         if (already_tracked)
2008         {
2009             // FIXME loops like we want to stop all theads here.
2010             // StopAllThreads
2011 
2012             // We can now resume the newly created thread since it is fully created.
2013             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2014             Resume (tid, LLDB_INVALID_SIGNAL_NUMBER);
2015         }
2016         else
2017         {
2018             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2019             // this thread is ready to go.
2020             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2021         }
2022 
2023         // In all cases, we can resume the main thread here.
2024         Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2025         break;
2026     }
2027 
2028     case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)):
2029         if (log)
2030             log->Printf ("NativeProcessLinux::%s() received exec event, code = %d", __FUNCTION__, info->si_code ^ SIGTRAP);
2031         // FIXME stop all threads, mark thread stop reason as ThreadStopInfo.reason = eStopReasonExec;
2032         break;
2033 
2034     case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)):
2035     {
2036         // The inferior process or one of its threads is about to exit.
2037         // Maintain the process or thread in a state of "limbo" until we are
2038         // explicitly commanded to detach, destroy, resume, etc.
2039         unsigned long data = 0;
2040         if (!GetEventMessage(pid, &data))
2041             data = -1;
2042 
2043         if (log)
2044         {
2045             log->Printf ("NativeProcessLinux::%s() received PTRACE_EVENT_EXIT, data = %lx (WIFEXITED=%s,WIFSIGNALED=%s), pid = %" PRIu64 " (%s)",
2046                          __FUNCTION__,
2047                          data, WIFEXITED (data) ? "true" : "false", WIFSIGNALED (data) ? "true" : "false",
2048                          pid,
2049                     is_main_thread ? "is main thread" : "not main thread");
2050         }
2051 
2052         // Set the thread to exited.
2053         if (thread_sp)
2054             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetExited ();
2055         else
2056         {
2057             if (log)
2058                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " failed to retrieve thread for tid %" PRIu64", cannot set thread state", __FUNCTION__, GetID (), pid);
2059         }
2060 
2061         if (is_main_thread)
2062         {
2063             SetExitStatus (convert_pid_status_to_exit_type (data), convert_pid_status_to_return_code (data), nullptr, true);
2064             // Resume the thread so it completely exits.
2065             Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2066         }
2067         else
2068         {
2069             // FIXME figure out the path where we plan to reap the metadata for the thread.
2070         }
2071 
2072         break;
2073     }
2074 
2075     case 0:
2076     case TRAP_TRACE:
2077         // We receive this on single stepping.
2078         if (log)
2079             log->Printf ("NativeProcessLinux::%s() received trace event, pid = %" PRIu64 " (single stepping)", __FUNCTION__, pid);
2080 
2081         if (thread_sp)
2082         {
2083             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2084             SetCurrentThreadID (thread_sp->GetID ());
2085         }
2086         else
2087         {
2088             if (log)
2089                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 " single stepping received trace but thread not found", __FUNCTION__, GetID (), pid);
2090         }
2091 
2092         // Tell the process we have a stop (from single stepping).
2093         SetState (StateType::eStateStopped, true);
2094         break;
2095 
2096     case SI_KERNEL:
2097     case TRAP_BRKPT:
2098         if (log)
2099             log->Printf ("NativeProcessLinux::%s() received breakpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2100 
2101         // Mark the thread as stopped at breakpoint.
2102         if (thread_sp)
2103         {
2104             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2105             Error error = FixupBreakpointPCAsNeeded (thread_sp);
2106             if (error.Fail ())
2107             {
2108                 if (log)
2109                     log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " fixup: %s", __FUNCTION__, pid, error.AsCString ());
2110             }
2111         }
2112         else
2113         {
2114             if (log)
2115                 log->Printf ("NativeProcessLinux::%s()  pid = %" PRIu64 ": warning, cannot process software breakpoint since no thread metadata", __FUNCTION__, pid);
2116         }
2117 
2118 
2119         // Tell the process we have a stop from this thread.
2120         SetCurrentThreadID (pid);
2121         SetState (StateType::eStateStopped, true);
2122         break;
2123 
2124     case TRAP_HWBKPT:
2125         if (log)
2126             log->Printf ("NativeProcessLinux::%s() received watchpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2127 
2128         // Mark the thread as stopped at watchpoint.
2129         // The address is at (lldb::addr_t)info->si_addr if we need it.
2130         if (thread_sp)
2131             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2132         else
2133         {
2134             if (log)
2135                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ": warning, cannot process hardware breakpoint since no thread metadata", __FUNCTION__, GetID (), pid);
2136         }
2137 
2138         // Tell the process we have a stop from this thread.
2139         SetCurrentThreadID (pid);
2140         SetState (StateType::eStateStopped, true);
2141         break;
2142 
2143     case SIGTRAP:
2144     case (SIGTRAP | 0x80):
2145         if (log)
2146             log->Printf ("NativeProcessLinux::%s() received system call stop event, pid %" PRIu64 "tid %" PRIu64, __FUNCTION__, GetID (), pid);
2147         // Ignore these signals until we know more about them.
2148         Resume(pid, 0);
2149         break;
2150 
2151     default:
2152         assert(false && "Unexpected SIGTRAP code!");
2153         if (log)
2154             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 "tid %" PRIu64 " received unhandled SIGTRAP code: 0x%" PRIx64, __FUNCTION__, GetID (), pid, static_cast<uint64_t> (SIGTRAP | (PTRACE_EVENT_CLONE << 8)));
2155         break;
2156 
2157     }
2158 }
2159 
2160 void
2161 NativeProcessLinux::MonitorSignal(const siginfo_t *info, lldb::pid_t pid, bool exited)
2162 {
2163     int signo = info->si_signo;
2164 
2165     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2166 
2167     // POSIX says that process behaviour is undefined after it ignores a SIGFPE,
2168     // SIGILL, SIGSEGV, or SIGBUS *unless* that signal was generated by a
2169     // kill(2) or raise(3).  Similarly for tgkill(2) on Linux.
2170     //
2171     // IOW, user generated signals never generate what we consider to be a
2172     // "crash".
2173     //
2174     // Similarly, ACK signals generated by this monitor.
2175 
2176     // See if we can find a thread for this signal.
2177     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2178     if (!thread_sp)
2179     {
2180         if (log)
2181             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2182     }
2183 
2184     // Handle the signal.
2185     if (info->si_code == SI_TKILL || info->si_code == SI_USER)
2186     {
2187         if (log)
2188             log->Printf ("NativeProcessLinux::%s() received signal %s (%d) with code %s, (siginfo pid = %d (%s), waitpid pid = %" PRIu64 ")",
2189                             __FUNCTION__,
2190                             GetUnixSignals ().GetSignalAsCString (signo),
2191                             signo,
2192                             (info->si_code == SI_TKILL ? "SI_TKILL" : "SI_USER"),
2193                             info->si_pid,
2194                             (info->si_pid == getpid ()) ? "is monitor" : "is not monitor",
2195                             pid);
2196     }
2197 
2198     // Check for new thread notification.
2199     if ((info->si_pid == 0) && (info->si_code == SI_USER))
2200     {
2201         // A new thread creation is being signaled.  This is one of two parts that come in
2202         // a non-deterministic order.  pid is the thread id.
2203         if (log)
2204             log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": new thread notification",
2205                      __FUNCTION__, GetID (), pid);
2206 
2207         // Did we already create the thread?
2208         bool already_tracked = false;
2209         thread_sp = GetOrCreateThread (pid, already_tracked);
2210         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2211 
2212         // If the thread was already tracked, it means the main thread already received its SIGTRAP for the create.
2213         if (already_tracked)
2214         {
2215             // We can now resume this thread up since it is fully created.
2216             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2217             Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2218         }
2219         else
2220         {
2221             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2222             // this thread is ready to go.
2223             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2224         }
2225 
2226         // Done handling.
2227         return;
2228     }
2229 
2230     // Check for thread stop notification.
2231     if ((info->si_pid == getpid ()) && (info->si_code == SI_TKILL) && (signo == SIGSTOP))
2232     {
2233         // This is a tgkill()-based stop.
2234         if (thread_sp)
2235         {
2236             // An inferior thread just stopped.  Mark it as such.
2237             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2238             SetCurrentThreadID (thread_sp->GetID ());
2239 
2240             // Remove this tid from the wait-for-stop set.
2241             Mutex::Locker locker (m_wait_for_stop_tids_mutex);
2242 
2243             auto removed_count = m_wait_for_stop_tids.erase (thread_sp->GetID ());
2244             if (removed_count < 1)
2245             {
2246                 log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": tgkill()-stopped thread not in m_wait_for_stop_tids",
2247                              __FUNCTION__, GetID (), thread_sp->GetID ());
2248 
2249             }
2250 
2251             // If this is the last thread in the m_wait_for_stop_tids, we need to notify
2252             // the delegate that a stop has occurred now that every thread that was supposed
2253             // to stop has stopped.
2254             if (m_wait_for_stop_tids.empty ())
2255             {
2256                 if (log)
2257                 {
2258                     log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ", setting process state to stopped now that all tids marked for stop have completed",
2259                                  __FUNCTION__,
2260                                  GetID (),
2261                                  pid);
2262                 }
2263                 SetState (StateType::eStateStopped, true);
2264             }
2265         }
2266 
2267         // Done handling.
2268         return;
2269     }
2270 
2271     if (log)
2272         log->Printf ("NativeProcessLinux::%s() received signal %s", __FUNCTION__, GetUnixSignals ().GetSignalAsCString (signo));
2273 
2274     switch (signo)
2275     {
2276     case SIGSEGV:
2277         {
2278             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2279 
2280             // FIXME figure out how to propagate this properly.  Seems like it
2281             // should go in ThreadStopInfo.
2282             // We can get more details on the exact nature of the crash here.
2283             // ProcessMessage::CrashReason reason = GetCrashReasonForSIGSEGV(info);
2284             if (!exited)
2285             {
2286                 // This is just a pre-signal-delivery notification of the incoming signal.
2287                 // Send a stop to the debugger.
2288                 if (thread_sp)
2289                 {
2290                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2291                     SetCurrentThreadID (thread_sp->GetID ());
2292                 }
2293                 SetState (StateType::eStateStopped, true);
2294             }
2295             else
2296             {
2297                 if (thread_sp)
2298                 {
2299                     // FIXME figure out what type this is.
2300                     const uint64_t exception_type = static_cast<uint64_t> (SIGSEGV);
2301                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2302                 }
2303                 SetState (StateType::eStateCrashed, true);
2304             }
2305         }
2306         break;
2307 
2308     case SIGABRT:
2309     case SIGILL:
2310     case SIGFPE:
2311     case SIGBUS:
2312         {
2313             // Break these out into separate cases once I have more data for each type of signal.
2314             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2315             if (!exited)
2316             {
2317                 // This is just a pre-signal-delivery notification of the incoming signal.
2318                 // Send a stop to the debugger.
2319                 if (thread_sp)
2320                 {
2321                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2322                     SetCurrentThreadID (thread_sp->GetID ());
2323                 }
2324                 SetState (StateType::eStateStopped, true);
2325             }
2326             else
2327             {
2328                 if (thread_sp)
2329                 {
2330                     // FIXME figure out how to report exit by signal correctly.
2331                     const uint64_t exception_type = static_cast<uint64_t> (SIGABRT);
2332                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2333                 }
2334                 SetState (StateType::eStateCrashed, true);
2335             }
2336         }
2337         break;
2338 
2339     default:
2340         if (log)
2341             log->Printf ("NativeProcessLinux::%s unhandled signal %s (%d)", __FUNCTION__, GetUnixSignals ().GetSignalAsCString (signo), signo);
2342         break;
2343     }
2344 }
2345 
2346 Error
2347 NativeProcessLinux::Resume (const ResumeActionList &resume_actions)
2348 {
2349     Error error;
2350 
2351     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_THREAD));
2352     if (log)
2353         log->Printf ("NativeProcessLinux::%s called: pid %" PRIu64, __FUNCTION__, GetID ());
2354 
2355     int run_thread_count = 0;
2356     int stop_thread_count = 0;
2357     int step_thread_count = 0;
2358 
2359     std::vector<NativeThreadProtocolSP> new_stop_threads;
2360 
2361     Mutex::Locker locker (m_threads_mutex);
2362     for (auto thread_sp : m_threads)
2363     {
2364         assert (thread_sp && "thread list should not contain NULL threads");
2365         NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get ());
2366 
2367         const ResumeAction *const action = resume_actions.GetActionForThread (thread_sp->GetID (), true);
2368         assert (action && "NULL ResumeAction returned for thread during Resume ()");
2369 
2370         if (log)
2371         {
2372             log->Printf ("NativeProcessLinux::%s processing resume action state %s for pid %" PRIu64 " tid %" PRIu64,
2373                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2374         }
2375 
2376         switch (action->state)
2377         {
2378         case eStateRunning:
2379             // Run the thread, possibly feeding it the signal.
2380             linux_thread_p->SetRunning ();
2381             if (action->signal > 0)
2382             {
2383                 // Resume the thread and deliver the given signal,
2384                 // then mark as delivered.
2385                 Resume (thread_sp->GetID (), action->signal);
2386                 resume_actions.SetSignalHandledForThread (thread_sp->GetID ());
2387             }
2388             else
2389             {
2390                 // Just resume the thread with no signal.
2391                 Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2392             }
2393             ++run_thread_count;
2394             break;
2395 
2396         case eStateStepping:
2397             // Note: if we have multiple threads, we may need to stop
2398             // the other threads first, then step this one.
2399             linux_thread_p->SetStepping ();
2400             if (SingleStep (thread_sp->GetID (), 0))
2401             {
2402                 if (log)
2403                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step succeeded",
2404                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2405             }
2406             else
2407             {
2408                 if (log)
2409                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step failed",
2410                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2411             }
2412             ++step_thread_count;
2413             break;
2414 
2415         case eStateSuspended:
2416         case eStateStopped:
2417             if (!StateIsStoppedState (linux_thread_p->GetState (), false))
2418                 new_stop_threads.push_back (thread_sp);
2419             else
2420             {
2421                 if (log)
2422                     log->Printf ("NativeProcessLinux::%s no need to stop pid %" PRIu64 " tid %" PRIu64 ", thread state already %s",
2423                                  __FUNCTION__, GetID (), thread_sp->GetID (), StateAsCString (linux_thread_p->GetState ()));
2424             }
2425 
2426             ++stop_thread_count;
2427             break;
2428 
2429         default:
2430             return Error ("NativeProcessLinux::%s (): unexpected state %s specified for pid %" PRIu64 ", tid %" PRIu64,
2431                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2432         }
2433     }
2434 
2435     // If any thread was set to run, notify the process state as running.
2436     if (run_thread_count > 0)
2437         SetState (StateType::eStateRunning, true);
2438 
2439     // Now do a tgkill SIGSTOP on each thread we want to stop.
2440     if (!new_stop_threads.empty ())
2441     {
2442         // Lock the m_wait_for_stop_tids set so we can fill it with every thread we expect to have stopped.
2443         Mutex::Locker stop_thread_id_locker (m_wait_for_stop_tids_mutex);
2444         for (auto thread_sp : new_stop_threads)
2445         {
2446             // Send a stop signal to the thread.
2447             const int result = tgkill (GetID (), thread_sp->GetID (), SIGSTOP);
2448             if (result != 0)
2449             {
2450                 // tgkill failed.
2451                 if (log)
2452                     log->Printf ("NativeProcessLinux::%s error: tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 "failed, retval %d",
2453                                  __FUNCTION__, GetID (), thread_sp->GetID (), result);
2454             }
2455             else
2456             {
2457                 // tgkill succeeded.  Don't mark the thread state, though.  Let the signal
2458                 // handling mark it.
2459                 if (log)
2460                     log->Printf ("NativeProcessLinux::%s tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 " succeeded",
2461                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2462 
2463                 // Add it to the set of threads we expect to signal a stop.
2464                 // We won't tell the delegate about it until this list drains to empty.
2465                 m_wait_for_stop_tids.insert (thread_sp->GetID ());
2466             }
2467         }
2468     }
2469 
2470     return error;
2471 }
2472 
2473 Error
2474 NativeProcessLinux::Halt ()
2475 {
2476     Error error;
2477 
2478     // FIXME check if we're already stopped
2479     const bool is_stopped = false;
2480     if (is_stopped)
2481         return error;
2482 
2483     if (kill (GetID (), SIGSTOP) != 0)
2484         error.SetErrorToErrno ();
2485 
2486     return error;
2487 }
2488 
2489 Error
2490 NativeProcessLinux::Detach ()
2491 {
2492     Error error;
2493 
2494     // Tell ptrace to detach from the process.
2495     if (GetID () != LLDB_INVALID_PROCESS_ID)
2496         error = Detach (GetID ());
2497 
2498     // Stop monitoring the inferior.
2499     StopMonitor ();
2500 
2501     // No error.
2502     return error;
2503 }
2504 
2505 Error
2506 NativeProcessLinux::Signal (int signo)
2507 {
2508     Error error;
2509 
2510     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2511     if (log)
2512         log->Printf ("NativeProcessLinux::%s: sending signal %d (%s) to pid %" PRIu64,
2513                 __FUNCTION__, signo,  GetUnixSignals ().GetSignalAsCString (signo), GetID ());
2514 
2515     if (kill(GetID(), signo))
2516         error.SetErrorToErrno();
2517 
2518     return error;
2519 }
2520 
2521 Error
2522 NativeProcessLinux::Kill ()
2523 {
2524     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2525     if (log)
2526         log->Printf ("NativeProcessLinux::%s called for PID %" PRIu64, __FUNCTION__, GetID ());
2527 
2528     Error error;
2529 
2530     switch (m_state)
2531     {
2532         case StateType::eStateInvalid:
2533         case StateType::eStateExited:
2534         case StateType::eStateCrashed:
2535         case StateType::eStateDetached:
2536         case StateType::eStateUnloaded:
2537             // Nothing to do - the process is already dead.
2538             if (log)
2539                 log->Printf ("NativeProcessLinux::%s ignored for PID %" PRIu64 " due to current state: %s", __FUNCTION__, GetID (), StateAsCString (m_state));
2540             return error;
2541 
2542         case StateType::eStateConnected:
2543         case StateType::eStateAttaching:
2544         case StateType::eStateLaunching:
2545         case StateType::eStateStopped:
2546         case StateType::eStateRunning:
2547         case StateType::eStateStepping:
2548         case StateType::eStateSuspended:
2549             // We can try to kill a process in these states.
2550             break;
2551     }
2552 
2553     if (kill (GetID (), SIGKILL) != 0)
2554     {
2555         error.SetErrorToErrno ();
2556         return error;
2557     }
2558 
2559     return error;
2560 }
2561 
2562 static Error
2563 ParseMemoryRegionInfoFromProcMapsLine (const std::string &maps_line, MemoryRegionInfo &memory_region_info)
2564 {
2565     memory_region_info.Clear();
2566 
2567     StringExtractor line_extractor (maps_line.c_str ());
2568 
2569     // Format: {address_start_hex}-{address_end_hex} perms offset  dev   inode   pathname
2570     // perms: rwxp   (letter is present if set, '-' if not, final character is p=private, s=shared).
2571 
2572     // Parse out the starting address
2573     lldb::addr_t start_address = line_extractor.GetHexMaxU64 (false, 0);
2574 
2575     // Parse out hyphen separating start and end address from range.
2576     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != '-'))
2577         return Error ("malformed /proc/{pid}/maps entry, missing dash between address range");
2578 
2579     // Parse out the ending address
2580     lldb::addr_t end_address = line_extractor.GetHexMaxU64 (false, start_address);
2581 
2582     // Parse out the space after the address.
2583     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != ' '))
2584         return Error ("malformed /proc/{pid}/maps entry, missing space after range");
2585 
2586     // Save the range.
2587     memory_region_info.GetRange ().SetRangeBase (start_address);
2588     memory_region_info.GetRange ().SetRangeEnd (end_address);
2589 
2590     // Parse out each permission entry.
2591     if (line_extractor.GetBytesLeft () < 4)
2592         return Error ("malformed /proc/{pid}/maps entry, missing some portion of permissions");
2593 
2594     // Handle read permission.
2595     const char read_perm_char = line_extractor.GetChar ();
2596     if (read_perm_char == 'r')
2597         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eYes);
2598     else
2599     {
2600         assert ( (read_perm_char == '-') && "unexpected /proc/{pid}/maps read permission char" );
2601         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
2602     }
2603 
2604     // Handle write permission.
2605     const char write_perm_char = line_extractor.GetChar ();
2606     if (write_perm_char == 'w')
2607         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eYes);
2608     else
2609     {
2610         assert ( (write_perm_char == '-') && "unexpected /proc/{pid}/maps write permission char" );
2611         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
2612     }
2613 
2614     // Handle execute permission.
2615     const char exec_perm_char = line_extractor.GetChar ();
2616     if (exec_perm_char == 'x')
2617         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eYes);
2618     else
2619     {
2620         assert ( (exec_perm_char == '-') && "unexpected /proc/{pid}/maps exec permission char" );
2621         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
2622     }
2623 
2624     return Error ();
2625 }
2626 
2627 Error
2628 NativeProcessLinux::GetMemoryRegionInfo (lldb::addr_t load_addr, MemoryRegionInfo &range_info)
2629 {
2630     // FIXME review that the final memory region returned extends to the end of the virtual address space,
2631     // with no perms if it is not mapped.
2632 
2633     // Use an approach that reads memory regions from /proc/{pid}/maps.
2634     // Assume proc maps entries are in ascending order.
2635     // FIXME assert if we find differently.
2636     Mutex::Locker locker (m_mem_region_cache_mutex);
2637 
2638     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2639     Error error;
2640 
2641     if (m_supports_mem_region == LazyBool::eLazyBoolNo)
2642     {
2643         // We're done.
2644         error.SetErrorString ("unsupported");
2645         return error;
2646     }
2647 
2648     // If our cache is empty, pull the latest.  There should always be at least one memory region
2649     // if memory region handling is supported.
2650     if (m_mem_region_cache.empty ())
2651     {
2652         error = ProcFileReader::ProcessLineByLine (GetID (), "maps",
2653              [&] (const std::string &line) -> bool
2654              {
2655                  MemoryRegionInfo info;
2656                  const Error parse_error = ParseMemoryRegionInfoFromProcMapsLine (line, info);
2657                  if (parse_error.Success ())
2658                  {
2659                      m_mem_region_cache.push_back (info);
2660                      return true;
2661                  }
2662                  else
2663                  {
2664                      if (log)
2665                          log->Printf ("NativeProcessLinux::%s failed to parse proc maps line '%s': %s", __FUNCTION__, line.c_str (), error.AsCString ());
2666                      return false;
2667                  }
2668              });
2669 
2670         // If we had an error, we'll mark unsupported.
2671         if (error.Fail ())
2672         {
2673             m_supports_mem_region = LazyBool::eLazyBoolNo;
2674             return error;
2675         }
2676         else if (m_mem_region_cache.empty ())
2677         {
2678             // No entries after attempting to read them.  This shouldn't happen if /proc/{pid}/maps
2679             // is supported.  Assume we don't support map entries via procfs.
2680             if (log)
2681                 log->Printf ("NativeProcessLinux::%s failed to find any procfs maps entries, assuming no support for memory region metadata retrieval", __FUNCTION__);
2682             m_supports_mem_region = LazyBool::eLazyBoolNo;
2683             error.SetErrorString ("not supported");
2684             return error;
2685         }
2686 
2687         if (log)
2688             log->Printf ("NativeProcessLinux::%s read %" PRIu64 " memory region entries from /proc/%" PRIu64 "/maps", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()), GetID ());
2689 
2690         // We support memory retrieval, remember that.
2691         m_supports_mem_region = LazyBool::eLazyBoolYes;
2692     }
2693     else
2694     {
2695         if (log)
2696             log->Printf ("NativeProcessLinux::%s reusing %" PRIu64 " cached memory region entries", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
2697     }
2698 
2699     lldb::addr_t prev_base_address = 0;
2700 
2701     // FIXME start by finding the last region that is <= target address using binary search.  Data is sorted.
2702     // There can be a ton of regions on pthreads apps with lots of threads.
2703     for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end (); ++it)
2704     {
2705         MemoryRegionInfo &proc_entry_info = *it;
2706 
2707         // Sanity check assumption that /proc/{pid}/maps entries are ascending.
2708         assert ((proc_entry_info.GetRange ().GetRangeBase () >= prev_base_address) && "descending /proc/pid/maps entries detected, unexpected");
2709         prev_base_address = proc_entry_info.GetRange ().GetRangeBase ();
2710 
2711         // If the target address comes before this entry, indicate distance to next region.
2712         if (load_addr < proc_entry_info.GetRange ().GetRangeBase ())
2713         {
2714             range_info.GetRange ().SetRangeBase (load_addr);
2715             range_info.GetRange ().SetByteSize (proc_entry_info.GetRange ().GetRangeBase () - load_addr);
2716             range_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
2717             range_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
2718             range_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
2719 
2720             return error;
2721         }
2722         else if (proc_entry_info.GetRange ().Contains (load_addr))
2723         {
2724             // The target address is within the memory region we're processing here.
2725             range_info = proc_entry_info;
2726             return error;
2727         }
2728 
2729         // The target memory address comes somewhere after the region we just parsed.
2730     }
2731 
2732     // If we made it here, we didn't find an entry that contained the given address.
2733     error.SetErrorString ("address comes after final region");
2734 
2735     if (log)
2736         log->Printf ("NativeProcessLinux::%s failed to find map entry for address 0x%" PRIx64 ": %s", __FUNCTION__, load_addr, error.AsCString ());
2737 
2738     return error;
2739 }
2740 
2741 void
2742 NativeProcessLinux::DoStopIDBumped (uint32_t newBumpId)
2743 {
2744     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2745     if (log)
2746         log->Printf ("NativeProcessLinux::%s(newBumpId=%" PRIu32 ") called", __FUNCTION__, newBumpId);
2747 
2748     {
2749         Mutex::Locker locker (m_mem_region_cache_mutex);
2750         if (log)
2751             log->Printf ("NativeProcessLinux::%s clearing %" PRIu64 " entries from the cache", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
2752         m_mem_region_cache.clear ();
2753     }
2754 }
2755 
2756 Error
2757 NativeProcessLinux::AllocateMemory (
2758     lldb::addr_t size,
2759     uint32_t permissions,
2760     lldb::addr_t &addr)
2761 {
2762     // FIXME implementing this requires the equivalent of
2763     // InferiorCallPOSIX::InferiorCallMmap, which depends on
2764     // functional ThreadPlans working with Native*Protocol.
2765 #if 1
2766     return Error ("not implemented yet");
2767 #else
2768     addr = LLDB_INVALID_ADDRESS;
2769 
2770     unsigned prot = 0;
2771     if (permissions & lldb::ePermissionsReadable)
2772         prot |= eMmapProtRead;
2773     if (permissions & lldb::ePermissionsWritable)
2774         prot |= eMmapProtWrite;
2775     if (permissions & lldb::ePermissionsExecutable)
2776         prot |= eMmapProtExec;
2777 
2778     // TODO implement this directly in NativeProcessLinux
2779     // (and lift to NativeProcessPOSIX if/when that class is
2780     // refactored out).
2781     if (InferiorCallMmap(this, addr, 0, size, prot,
2782                          eMmapFlagsAnon | eMmapFlagsPrivate, -1, 0)) {
2783         m_addr_to_mmap_size[addr] = size;
2784         return Error ();
2785     } else {
2786         addr = LLDB_INVALID_ADDRESS;
2787         return Error("unable to allocate %" PRIu64 " bytes of memory with permissions %s", size, GetPermissionsAsCString (permissions));
2788     }
2789 #endif
2790 }
2791 
2792 Error
2793 NativeProcessLinux::DeallocateMemory (lldb::addr_t addr)
2794 {
2795     // FIXME see comments in AllocateMemory - required lower-level
2796     // bits not in place yet (ThreadPlans)
2797     return Error ("not implemented");
2798 }
2799 
2800 lldb::addr_t
2801 NativeProcessLinux::GetSharedLibraryInfoAddress ()
2802 {
2803 #if 1
2804     // punt on this for now
2805     return LLDB_INVALID_ADDRESS;
2806 #else
2807     // Return the image info address for the exe module
2808 #if 1
2809     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2810 
2811     ModuleSP module_sp;
2812     Error error = GetExeModuleSP (module_sp);
2813     if (error.Fail ())
2814     {
2815          if (log)
2816             log->Warning ("NativeProcessLinux::%s failed to retrieve exe module: %s", __FUNCTION__, error.AsCString ());
2817         return LLDB_INVALID_ADDRESS;
2818     }
2819 
2820     if (module_sp == nullptr)
2821     {
2822          if (log)
2823             log->Warning ("NativeProcessLinux::%s exe module returned was NULL", __FUNCTION__);
2824          return LLDB_INVALID_ADDRESS;
2825     }
2826 
2827     ObjectFileSP object_file_sp = module_sp->GetObjectFile ();
2828     if (object_file_sp == nullptr)
2829     {
2830          if (log)
2831             log->Warning ("NativeProcessLinux::%s exe module returned a NULL object file", __FUNCTION__);
2832          return LLDB_INVALID_ADDRESS;
2833     }
2834 
2835     return obj_file_sp->GetImageInfoAddress();
2836 #else
2837     Target *target = &GetTarget();
2838     ObjectFile *obj_file = target->GetExecutableModule()->GetObjectFile();
2839     Address addr = obj_file->GetImageInfoAddress(target);
2840 
2841     if (addr.IsValid())
2842         return addr.GetLoadAddress(target);
2843     return LLDB_INVALID_ADDRESS;
2844 #endif
2845 #endif // punt on this for now
2846 }
2847 
2848 size_t
2849 NativeProcessLinux::UpdateThreads ()
2850 {
2851     // The NativeProcessLinux monitoring threads are always up to date
2852     // with respect to thread state and they keep the thread list
2853     // populated properly. All this method needs to do is return the
2854     // thread count.
2855     Mutex::Locker locker (m_threads_mutex);
2856     return m_threads.size ();
2857 }
2858 
2859 bool
2860 NativeProcessLinux::GetArchitecture (ArchSpec &arch) const
2861 {
2862     arch = m_arch;
2863     return true;
2864 }
2865 
2866 Error
2867 NativeProcessLinux::GetSoftwareBreakpointSize (NativeRegisterContextSP context_sp, uint32_t &actual_opcode_size)
2868 {
2869     // FIXME put this behind a breakpoint protocol class that can be
2870     // set per architecture.  Need ARM, MIPS support here.
2871     static const uint8_t g_i386_opcode [] = { 0xCC };
2872 
2873     switch (m_arch.GetMachine ())
2874     {
2875         case llvm::Triple::x86:
2876         case llvm::Triple::x86_64:
2877             actual_opcode_size = static_cast<uint32_t> (sizeof(g_i386_opcode));
2878             return Error ();
2879 
2880         default:
2881             assert(false && "CPU type not supported!");
2882             return Error ("CPU type not supported");
2883     }
2884 }
2885 
2886 Error
2887 NativeProcessLinux::SetBreakpoint (lldb::addr_t addr, uint32_t size, bool hardware)
2888 {
2889     if (hardware)
2890         return Error ("NativeProcessLinux does not support hardware breakpoints");
2891     else
2892         return SetSoftwareBreakpoint (addr, size);
2893 }
2894 
2895 Error
2896 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode (size_t trap_opcode_size_hint, size_t &actual_opcode_size, const uint8_t *&trap_opcode_bytes)
2897 {
2898     // FIXME put this behind a breakpoint protocol class that can be
2899     // set per architecture.  Need ARM, MIPS support here.
2900     static const uint8_t g_i386_opcode [] = { 0xCC };
2901 
2902     switch (m_arch.GetMachine ())
2903     {
2904     case llvm::Triple::x86:
2905     case llvm::Triple::x86_64:
2906         trap_opcode_bytes = g_i386_opcode;
2907         actual_opcode_size = sizeof(g_i386_opcode);
2908         return Error ();
2909 
2910     default:
2911         assert(false && "CPU type not supported!");
2912         return Error ("CPU type not supported");
2913     }
2914 }
2915 
2916 #if 0
2917 ProcessMessage::CrashReason
2918 NativeProcessLinux::GetCrashReasonForSIGSEGV(const siginfo_t *info)
2919 {
2920     ProcessMessage::CrashReason reason;
2921     assert(info->si_signo == SIGSEGV);
2922 
2923     reason = ProcessMessage::eInvalidCrashReason;
2924 
2925     switch (info->si_code)
2926     {
2927     default:
2928         assert(false && "unexpected si_code for SIGSEGV");
2929         break;
2930     case SI_KERNEL:
2931         // Linux will occasionally send spurious SI_KERNEL codes.
2932         // (this is poorly documented in sigaction)
2933         // One way to get this is via unaligned SIMD loads.
2934         reason = ProcessMessage::eInvalidAddress; // for lack of anything better
2935         break;
2936     case SEGV_MAPERR:
2937         reason = ProcessMessage::eInvalidAddress;
2938         break;
2939     case SEGV_ACCERR:
2940         reason = ProcessMessage::ePrivilegedAddress;
2941         break;
2942     }
2943 
2944     return reason;
2945 }
2946 #endif
2947 
2948 
2949 #if 0
2950 ProcessMessage::CrashReason
2951 NativeProcessLinux::GetCrashReasonForSIGILL(const siginfo_t *info)
2952 {
2953     ProcessMessage::CrashReason reason;
2954     assert(info->si_signo == SIGILL);
2955 
2956     reason = ProcessMessage::eInvalidCrashReason;
2957 
2958     switch (info->si_code)
2959     {
2960     default:
2961         assert(false && "unexpected si_code for SIGILL");
2962         break;
2963     case ILL_ILLOPC:
2964         reason = ProcessMessage::eIllegalOpcode;
2965         break;
2966     case ILL_ILLOPN:
2967         reason = ProcessMessage::eIllegalOperand;
2968         break;
2969     case ILL_ILLADR:
2970         reason = ProcessMessage::eIllegalAddressingMode;
2971         break;
2972     case ILL_ILLTRP:
2973         reason = ProcessMessage::eIllegalTrap;
2974         break;
2975     case ILL_PRVOPC:
2976         reason = ProcessMessage::ePrivilegedOpcode;
2977         break;
2978     case ILL_PRVREG:
2979         reason = ProcessMessage::ePrivilegedRegister;
2980         break;
2981     case ILL_COPROC:
2982         reason = ProcessMessage::eCoprocessorError;
2983         break;
2984     case ILL_BADSTK:
2985         reason = ProcessMessage::eInternalStackError;
2986         break;
2987     }
2988 
2989     return reason;
2990 }
2991 #endif
2992 
2993 #if 0
2994 ProcessMessage::CrashReason
2995 NativeProcessLinux::GetCrashReasonForSIGFPE(const siginfo_t *info)
2996 {
2997     ProcessMessage::CrashReason reason;
2998     assert(info->si_signo == SIGFPE);
2999 
3000     reason = ProcessMessage::eInvalidCrashReason;
3001 
3002     switch (info->si_code)
3003     {
3004     default:
3005         assert(false && "unexpected si_code for SIGFPE");
3006         break;
3007     case FPE_INTDIV:
3008         reason = ProcessMessage::eIntegerDivideByZero;
3009         break;
3010     case FPE_INTOVF:
3011         reason = ProcessMessage::eIntegerOverflow;
3012         break;
3013     case FPE_FLTDIV:
3014         reason = ProcessMessage::eFloatDivideByZero;
3015         break;
3016     case FPE_FLTOVF:
3017         reason = ProcessMessage::eFloatOverflow;
3018         break;
3019     case FPE_FLTUND:
3020         reason = ProcessMessage::eFloatUnderflow;
3021         break;
3022     case FPE_FLTRES:
3023         reason = ProcessMessage::eFloatInexactResult;
3024         break;
3025     case FPE_FLTINV:
3026         reason = ProcessMessage::eFloatInvalidOperation;
3027         break;
3028     case FPE_FLTSUB:
3029         reason = ProcessMessage::eFloatSubscriptRange;
3030         break;
3031     }
3032 
3033     return reason;
3034 }
3035 #endif
3036 
3037 #if 0
3038 ProcessMessage::CrashReason
3039 NativeProcessLinux::GetCrashReasonForSIGBUS(const siginfo_t *info)
3040 {
3041     ProcessMessage::CrashReason reason;
3042     assert(info->si_signo == SIGBUS);
3043 
3044     reason = ProcessMessage::eInvalidCrashReason;
3045 
3046     switch (info->si_code)
3047     {
3048     default:
3049         assert(false && "unexpected si_code for SIGBUS");
3050         break;
3051     case BUS_ADRALN:
3052         reason = ProcessMessage::eIllegalAlignment;
3053         break;
3054     case BUS_ADRERR:
3055         reason = ProcessMessage::eIllegalAddress;
3056         break;
3057     case BUS_OBJERR:
3058         reason = ProcessMessage::eHardwareError;
3059         break;
3060     }
3061 
3062     return reason;
3063 }
3064 #endif
3065 
3066 void
3067 NativeProcessLinux::ServeOperation(OperationArgs *args)
3068 {
3069     NativeProcessLinux *monitor = args->m_monitor;
3070 
3071     // We are finised with the arguments and are ready to go.  Sync with the
3072     // parent thread and start serving operations on the inferior.
3073     sem_post(&args->m_semaphore);
3074 
3075     for(;;)
3076     {
3077         // wait for next pending operation
3078         if (sem_wait(&monitor->m_operation_pending))
3079         {
3080             if (errno == EINTR)
3081                 continue;
3082             assert(false && "Unexpected errno from sem_wait");
3083         }
3084 
3085         reinterpret_cast<Operation*>(monitor->m_operation)->Execute(monitor);
3086 
3087         // notify calling thread that operation is complete
3088         sem_post(&monitor->m_operation_done);
3089     }
3090 }
3091 
3092 void
3093 NativeProcessLinux::DoOperation(void *op)
3094 {
3095     Mutex::Locker lock(m_operation_mutex);
3096 
3097     m_operation = op;
3098 
3099     // notify operation thread that an operation is ready to be processed
3100     sem_post(&m_operation_pending);
3101 
3102     // wait for operation to complete
3103     while (sem_wait(&m_operation_done))
3104     {
3105         if (errno == EINTR)
3106             continue;
3107         assert(false && "Unexpected errno from sem_wait");
3108     }
3109 }
3110 
3111 Error
3112 NativeProcessLinux::ReadMemory (lldb::addr_t addr, void *buf, lldb::addr_t size, lldb::addr_t &bytes_read)
3113 {
3114     ReadOperation op(addr, buf, size, bytes_read);
3115     DoOperation(&op);
3116     return op.GetError ();
3117 }
3118 
3119 Error
3120 NativeProcessLinux::WriteMemory (lldb::addr_t addr, const void *buf, lldb::addr_t size, lldb::addr_t &bytes_written)
3121 {
3122     WriteOperation op(addr, buf, size, bytes_written);
3123     DoOperation(&op);
3124     return op.GetError ();
3125 }
3126 
3127 bool
3128 NativeProcessLinux::ReadRegisterValue(lldb::tid_t tid, uint32_t offset, const char* reg_name,
3129                                   uint32_t size, RegisterValue &value)
3130 {
3131     bool result;
3132     ReadRegOperation op(tid, offset, reg_name, value, result);
3133     DoOperation(&op);
3134     return result;
3135 }
3136 
3137 bool
3138 NativeProcessLinux::WriteRegisterValue(lldb::tid_t tid, unsigned offset,
3139                                    const char* reg_name, const RegisterValue &value)
3140 {
3141     bool result;
3142     WriteRegOperation op(tid, offset, reg_name, value, result);
3143     DoOperation(&op);
3144     return result;
3145 }
3146 
3147 bool
3148 NativeProcessLinux::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3149 {
3150     bool result;
3151     ReadGPROperation op(tid, buf, buf_size, result);
3152     DoOperation(&op);
3153     return result;
3154 }
3155 
3156 bool
3157 NativeProcessLinux::ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3158 {
3159     bool result;
3160     ReadFPROperation op(tid, buf, buf_size, result);
3161     DoOperation(&op);
3162     return result;
3163 }
3164 
3165 bool
3166 NativeProcessLinux::ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3167 {
3168     bool result;
3169     ReadRegisterSetOperation op(tid, buf, buf_size, regset, result);
3170     DoOperation(&op);
3171     return result;
3172 }
3173 
3174 bool
3175 NativeProcessLinux::WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3176 {
3177     bool result;
3178     WriteGPROperation op(tid, buf, buf_size, result);
3179     DoOperation(&op);
3180     return result;
3181 }
3182 
3183 bool
3184 NativeProcessLinux::WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3185 {
3186     bool result;
3187     WriteFPROperation op(tid, buf, buf_size, result);
3188     DoOperation(&op);
3189     return result;
3190 }
3191 
3192 bool
3193 NativeProcessLinux::WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3194 {
3195     bool result;
3196     WriteRegisterSetOperation op(tid, buf, buf_size, regset, result);
3197     DoOperation(&op);
3198     return result;
3199 }
3200 
3201 bool
3202 NativeProcessLinux::Resume (lldb::tid_t tid, uint32_t signo)
3203 {
3204     bool result;
3205     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3206 
3207     if (log)
3208         log->Printf ("NativeProcessLinux::%s() resuming thread = %"  PRIu64 " with signal %s", __FUNCTION__, tid,
3209                                  GetUnixSignals().GetSignalAsCString (signo));
3210     ResumeOperation op (tid, signo, result);
3211     DoOperation (&op);
3212     if (log)
3213         log->Printf ("NativeProcessLinux::%s() resuming result = %s", __FUNCTION__, result ? "true" : "false");
3214     return result;
3215 }
3216 
3217 bool
3218 NativeProcessLinux::SingleStep(lldb::tid_t tid, uint32_t signo)
3219 {
3220     bool result;
3221     SingleStepOperation op(tid, signo, result);
3222     DoOperation(&op);
3223     return result;
3224 }
3225 
3226 bool
3227 NativeProcessLinux::GetSignalInfo(lldb::tid_t tid, void *siginfo, int &ptrace_err)
3228 {
3229     bool result;
3230     SiginfoOperation op(tid, siginfo, result, ptrace_err);
3231     DoOperation(&op);
3232     return result;
3233 }
3234 
3235 bool
3236 NativeProcessLinux::GetEventMessage(lldb::tid_t tid, unsigned long *message)
3237 {
3238     bool result;
3239     EventMessageOperation op(tid, message, result);
3240     DoOperation(&op);
3241     return result;
3242 }
3243 
3244 lldb_private::Error
3245 NativeProcessLinux::Detach(lldb::tid_t tid)
3246 {
3247     lldb_private::Error error;
3248     if (tid != LLDB_INVALID_THREAD_ID)
3249     {
3250         DetachOperation op(tid, error);
3251         DoOperation(&op);
3252     }
3253     return error;
3254 }
3255 
3256 bool
3257 NativeProcessLinux::DupDescriptor(const char *path, int fd, int flags)
3258 {
3259     int target_fd = open(path, flags, 0666);
3260 
3261     if (target_fd == -1)
3262         return false;
3263 
3264     return (dup2(target_fd, fd) == -1) ? false : true;
3265 }
3266 
3267 void
3268 NativeProcessLinux::StopMonitoringChildProcess()
3269 {
3270     lldb::thread_result_t thread_result;
3271 
3272     if (IS_VALID_LLDB_HOST_THREAD(m_monitor_thread))
3273     {
3274         Host::ThreadCancel(m_monitor_thread, NULL);
3275         Host::ThreadJoin(m_monitor_thread, &thread_result, NULL);
3276         m_monitor_thread = LLDB_INVALID_HOST_THREAD;
3277     }
3278 }
3279 
3280 void
3281 NativeProcessLinux::StopMonitor()
3282 {
3283     StopMonitoringChildProcess();
3284     StopOpThread();
3285     sem_destroy(&m_operation_pending);
3286     sem_destroy(&m_operation_done);
3287 
3288     // TODO: validate whether this still holds, fix up comment.
3289     // Note: ProcessPOSIX passes the m_terminal_fd file descriptor to
3290     // Process::SetSTDIOFileDescriptor, which in turn transfers ownership of
3291     // the descriptor to a ConnectionFileDescriptor object.  Consequently
3292     // even though still has the file descriptor, we shouldn't close it here.
3293 }
3294 
3295 void
3296 NativeProcessLinux::StopOpThread()
3297 {
3298     lldb::thread_result_t result;
3299 
3300     if (!IS_VALID_LLDB_HOST_THREAD(m_operation_thread))
3301         return;
3302 
3303     Host::ThreadCancel(m_operation_thread, NULL);
3304     Host::ThreadJoin(m_operation_thread, &result, NULL);
3305     m_operation_thread = LLDB_INVALID_HOST_THREAD;
3306 }
3307 
3308 bool
3309 NativeProcessLinux::HasThreadNoLock (lldb::tid_t thread_id)
3310 {
3311     for (auto thread_sp : m_threads)
3312     {
3313         assert (thread_sp && "thread list should not contain NULL threads");
3314         if (thread_sp->GetID () == thread_id)
3315         {
3316             // We have this thread.
3317             return true;
3318         }
3319     }
3320 
3321     // We don't have this thread.
3322     return false;
3323 }
3324 
3325 NativeThreadProtocolSP
3326 NativeProcessLinux::MaybeGetThreadNoLock (lldb::tid_t thread_id)
3327 {
3328     // CONSIDER organize threads by map - we can do better than linear.
3329     for (auto thread_sp : m_threads)
3330     {
3331         if (thread_sp->GetID () == thread_id)
3332             return thread_sp;
3333     }
3334 
3335     // We don't have this thread.
3336     return NativeThreadProtocolSP ();
3337 }
3338 
3339 bool
3340 NativeProcessLinux::StopTrackingThread (lldb::tid_t thread_id)
3341 {
3342     Mutex::Locker locker (m_threads_mutex);
3343     for (auto it = m_threads.begin (); it != m_threads.end (); ++it)
3344     {
3345         if (*it && ((*it)->GetID () == thread_id))
3346         {
3347             m_threads.erase (it);
3348             return true;
3349         }
3350     }
3351 
3352     // Didn't find it.
3353     return false;
3354 }
3355 
3356 NativeThreadProtocolSP
3357 NativeProcessLinux::AddThread (lldb::tid_t thread_id)
3358 {
3359     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3360 
3361     Mutex::Locker locker (m_threads_mutex);
3362 
3363     if (log)
3364     {
3365         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " adding thread with tid %" PRIu64,
3366                 __FUNCTION__,
3367                 GetID (),
3368                 thread_id);
3369     }
3370 
3371     assert (!HasThreadNoLock (thread_id) && "attempted to add a thread by id that already exists");
3372 
3373     // If this is the first thread, save it as the current thread
3374     if (m_threads.empty ())
3375         SetCurrentThreadID (thread_id);
3376 
3377     NativeThreadProtocolSP thread_sp (new NativeThreadLinux (this, thread_id));
3378     m_threads.push_back (thread_sp);
3379 
3380     return thread_sp;
3381 }
3382 
3383 NativeThreadProtocolSP
3384 NativeProcessLinux::GetOrCreateThread (lldb::tid_t thread_id, bool &created)
3385 {
3386     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3387 
3388     Mutex::Locker locker (m_threads_mutex);
3389     if (log)
3390     {
3391         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " get/create thread with tid %" PRIu64,
3392                      __FUNCTION__,
3393                      GetID (),
3394                      thread_id);
3395     }
3396 
3397     // Retrieve the thread if it is already getting tracked.
3398     NativeThreadProtocolSP thread_sp = MaybeGetThreadNoLock (thread_id);
3399     if (thread_sp)
3400     {
3401         if (log)
3402             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread already tracked, returning",
3403                          __FUNCTION__,
3404                          GetID (),
3405                          thread_id);
3406         created = false;
3407         return thread_sp;
3408 
3409     }
3410 
3411     // Create the thread metadata since it isn't being tracked.
3412     if (log)
3413         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread didn't exist, tracking now",
3414                      __FUNCTION__,
3415                      GetID (),
3416                      thread_id);
3417 
3418     thread_sp.reset (new NativeThreadLinux (this, thread_id));
3419     m_threads.push_back (thread_sp);
3420     created = true;
3421 
3422     return thread_sp;
3423 }
3424 
3425 Error
3426 NativeProcessLinux::FixupBreakpointPCAsNeeded (NativeThreadProtocolSP &thread_sp)
3427 {
3428     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3429 
3430     Error error;
3431 
3432     // Get a linux thread pointer.
3433     if (!thread_sp)
3434     {
3435         error.SetErrorString ("null thread_sp");
3436         if (log)
3437             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3438         return error;
3439     }
3440     NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get());
3441 
3442     // Find out the size of a breakpoint (might depend on where we are in the code).
3443     NativeRegisterContextSP context_sp = linux_thread_p->GetRegisterContext ();
3444     if (!context_sp)
3445     {
3446         error.SetErrorString ("cannot get a NativeRegisterContext for the thread");
3447         if (log)
3448             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3449         return error;
3450     }
3451 
3452     uint32_t breakpoint_size = 0;
3453     error = GetSoftwareBreakpointSize (context_sp, breakpoint_size);
3454     if (error.Fail ())
3455     {
3456         if (log)
3457             log->Printf ("NativeProcessLinux::%s GetBreakpointSize() failed: %s", __FUNCTION__, error.AsCString ());
3458         return error;
3459     }
3460     else
3461     {
3462         if (log)
3463             log->Printf ("NativeProcessLinux::%s breakpoint size: %" PRIu32, __FUNCTION__, breakpoint_size);
3464     }
3465 
3466     // First try probing for a breakpoint at a software breakpoint location: PC - breakpoint size.
3467     const lldb::addr_t initial_pc_addr = context_sp->GetPC ();
3468     lldb::addr_t breakpoint_addr = initial_pc_addr;
3469     if (breakpoint_size > static_cast<lldb::addr_t> (0))
3470     {
3471         // Do not allow breakpoint probe to wrap around.
3472         if (breakpoint_addr >= static_cast<lldb::addr_t> (breakpoint_size))
3473             breakpoint_addr -= static_cast<lldb::addr_t> (breakpoint_size);
3474     }
3475 
3476     // Check if we stopped because of a breakpoint.
3477     NativeBreakpointSP breakpoint_sp;
3478     error = m_breakpoint_list.GetBreakpoint (breakpoint_addr, breakpoint_sp);
3479     if (!error.Success () || !breakpoint_sp)
3480     {
3481         // We didn't find one at a software probe location.  Nothing to do.
3482         if (log)
3483             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " no lldb breakpoint found at current pc with adjustment: 0x%" PRIx64, __FUNCTION__, GetID (), breakpoint_addr);
3484         return Error ();
3485     }
3486 
3487     // If the breakpoint is not a software breakpoint, nothing to do.
3488     if (!breakpoint_sp->IsSoftwareBreakpoint ())
3489     {
3490         if (log)
3491             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " breakpoint found at 0x%" PRIx64 ", not software, nothing to adjust", __FUNCTION__, GetID (), breakpoint_addr);
3492         return Error ();
3493     }
3494 
3495     //
3496     // We have a software breakpoint and need to adjust the PC.
3497     //
3498 
3499     // Sanity check.
3500     if (breakpoint_size == 0)
3501     {
3502         // Nothing to do!  How did we get here?
3503         if (log)
3504             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " breakpoint found at 0x%" PRIx64 ", it is software, but the size is zero, nothing to do (unexpected)", __FUNCTION__, GetID (), breakpoint_addr);
3505         return Error ();
3506     }
3507 
3508     // Change the program counter.
3509     if (log)
3510         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": changing PC from 0x%" PRIx64 " to 0x%" PRIx64, __FUNCTION__, GetID (), linux_thread_p->GetID (), initial_pc_addr, breakpoint_addr);
3511 
3512     error = context_sp->SetPC (breakpoint_addr);
3513     if (error.Fail ())
3514     {
3515         if (log)
3516             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": failed to set PC: %s", __FUNCTION__, GetID (), linux_thread_p->GetID (), error.AsCString ());
3517         return error;
3518     }
3519 
3520     return error;
3521 }
3522