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