xref: /llvm-project/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp (revision 6edef20405d2f6ac190d796b215d6d288e8dc125)
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 #if defined(__ANDROID_NDK__) && defined (__arm__)
22 #include <linux/personality.h>
23 #include <linux/user.h>
24 #else
25 #include <sys/personality.h>
26 #include <sys/user.h>
27 #endif
28 #ifndef __ANDROID__
29 #include <sys/procfs.h>
30 #endif
31 #include <sys/ptrace.h>
32 #include <sys/uio.h>
33 #include <sys/socket.h>
34 #include <sys/syscall.h>
35 #include <sys/types.h>
36 #include <sys/wait.h>
37 
38 #if defined (__arm64__) || defined (__aarch64__)
39 // NT_PRSTATUS and NT_FPREGSET definition
40 #include <elf.h>
41 #endif
42 
43 // C++ Includes
44 #include <fstream>
45 #include <string>
46 
47 // Other libraries and framework includes
48 #include "lldb/Core/Debugger.h"
49 #include "lldb/Core/Error.h"
50 #include "lldb/Core/Module.h"
51 #include "lldb/Core/ModuleSpec.h"
52 #include "lldb/Core/RegisterValue.h"
53 #include "lldb/Core/Scalar.h"
54 #include "lldb/Core/State.h"
55 #include "lldb/Host/Host.h"
56 #include "lldb/Host/HostInfo.h"
57 #include "lldb/Host/ThreadLauncher.h"
58 #include "lldb/Symbol/ObjectFile.h"
59 #include "lldb/Target/NativeRegisterContext.h"
60 #include "lldb/Target/ProcessLaunchInfo.h"
61 #include "lldb/Utility/PseudoTerminal.h"
62 
63 #include "Host/common/NativeBreakpoint.h"
64 #include "Utility/StringExtractor.h"
65 
66 #include "Plugins/Process/Utility/LinuxSignals.h"
67 #include "NativeThreadLinux.h"
68 #include "ProcFileReader.h"
69 #include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
70 
71 #ifdef __ANDROID__
72 #define __ptrace_request int
73 #define PT_DETACH PTRACE_DETACH
74 #endif
75 
76 #define DEBUG_PTRACE_MAXBYTES 20
77 
78 // Support ptrace extensions even when compiled without required kernel support
79 #ifndef PT_GETREGS
80 #ifndef PTRACE_GETREGS
81   #define PTRACE_GETREGS 12
82 #endif
83 #endif
84 #ifndef PT_SETREGS
85 #ifndef PTRACE_SETREGS
86   #define PTRACE_SETREGS 13
87 #endif
88 #endif
89 #ifndef PT_GETFPREGS
90 #ifndef PTRACE_GETFPREGS
91   #define PTRACE_GETFPREGS 14
92 #endif
93 #endif
94 #ifndef PT_SETFPREGS
95 #ifndef PTRACE_SETFPREGS
96   #define PTRACE_SETFPREGS 15
97 #endif
98 #endif
99 #ifndef PTRACE_GETREGSET
100   #define PTRACE_GETREGSET 0x4204
101 #endif
102 #ifndef PTRACE_SETREGSET
103   #define PTRACE_SETREGSET 0x4205
104 #endif
105 #ifndef PTRACE_GET_THREAD_AREA
106   #define PTRACE_GET_THREAD_AREA 25
107 #endif
108 #ifndef PTRACE_ARCH_PRCTL
109   #define PTRACE_ARCH_PRCTL      30
110 #endif
111 #ifndef ARCH_GET_FS
112   #define ARCH_SET_GS 0x1001
113   #define ARCH_SET_FS 0x1002
114   #define ARCH_GET_FS 0x1003
115   #define ARCH_GET_GS 0x1004
116 #endif
117 
118 #define LLDB_PERSONALITY_GET_CURRENT_SETTINGS  0xffffffff
119 
120 // Support hardware breakpoints in case it has not been defined
121 #ifndef TRAP_HWBKPT
122   #define TRAP_HWBKPT 4
123 #endif
124 
125 // Try to define a macro to encapsulate the tgkill syscall
126 // fall back on kill() if tgkill isn't available
127 #define tgkill(pid, tid, sig)  syscall(SYS_tgkill, pid, tid, sig)
128 
129 // We disable the tracing of ptrace calls for integration builds to
130 // avoid the additional indirection and checks.
131 #ifndef LLDB_CONFIGURATION_BUILDANDINTEGRATION
132 #define PTRACE(req, pid, addr, data, data_size) \
133     PtraceWrapper((req), (pid), (addr), (data), (data_size), #req, __FILE__, __LINE__)
134 #else
135 #define PTRACE(req, pid, addr, data, data_size) \
136     PtraceWrapper((req), (pid), (addr), (data), (data_size))
137 #endif
138 
139 // Private bits we only need internally.
140 namespace
141 {
142     using namespace lldb;
143     using namespace lldb_private;
144 
145     const UnixSignals&
146     GetUnixSignals ()
147     {
148         static process_linux::LinuxSignals signals;
149         return signals;
150     }
151 
152     Error
153     ResolveProcessArchitecture (lldb::pid_t pid, Platform &platform, ArchSpec &arch)
154     {
155         // Grab process info for the running process.
156         ProcessInstanceInfo process_info;
157         if (!platform.GetProcessInfo (pid, process_info))
158             return lldb_private::Error("failed to get process info");
159 
160         // Resolve the executable module.
161         ModuleSP exe_module_sp;
162         ModuleSpec exe_module_spec(process_info.GetExecutableFile(), platform.GetSystemArchitecture ());
163         FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths ());
164         Error error = platform.ResolveExecutable(
165             process_info.GetExecutableFile (),
166             exe_module_sp,
167             executable_search_paths.GetSize () ? &executable_search_paths : NULL);
168 
169         if (!error.Success ())
170             return error;
171 
172         // Check if we've got our architecture from the exe_module.
173         arch = exe_module_sp->GetArchitecture ();
174         if (arch.IsValid ())
175             return Error();
176         else
177             return Error("failed to retrieve a valid architecture from the exe module");
178     }
179 
180     void
181     DisplayBytes (lldb_private::StreamString &s, void *bytes, uint32_t count)
182     {
183         uint8_t *ptr = (uint8_t *)bytes;
184         const uint32_t loop_count = std::min<uint32_t>(DEBUG_PTRACE_MAXBYTES, count);
185         for(uint32_t i=0; i<loop_count; i++)
186         {
187             s.Printf ("[%x]", *ptr);
188             ptr++;
189         }
190     }
191 
192     void
193     PtraceDisplayBytes(int &req, void *data, size_t data_size)
194     {
195         StreamString buf;
196         Log *verbose_log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (
197                     POSIX_LOG_PTRACE | POSIX_LOG_VERBOSE));
198 
199         if (verbose_log)
200         {
201             switch(req)
202             {
203             case PTRACE_POKETEXT:
204             {
205                 DisplayBytes(buf, &data, 8);
206                 verbose_log->Printf("PTRACE_POKETEXT %s", buf.GetData());
207                 break;
208             }
209             case PTRACE_POKEDATA:
210             {
211                 DisplayBytes(buf, &data, 8);
212                 verbose_log->Printf("PTRACE_POKEDATA %s", buf.GetData());
213                 break;
214             }
215             case PTRACE_POKEUSER:
216             {
217                 DisplayBytes(buf, &data, 8);
218                 verbose_log->Printf("PTRACE_POKEUSER %s", buf.GetData());
219                 break;
220             }
221             case PTRACE_SETREGS:
222             {
223                 DisplayBytes(buf, data, data_size);
224                 verbose_log->Printf("PTRACE_SETREGS %s", buf.GetData());
225                 break;
226             }
227             case PTRACE_SETFPREGS:
228             {
229                 DisplayBytes(buf, data, data_size);
230                 verbose_log->Printf("PTRACE_SETFPREGS %s", buf.GetData());
231                 break;
232             }
233             case PTRACE_SETSIGINFO:
234             {
235                 DisplayBytes(buf, data, sizeof(siginfo_t));
236                 verbose_log->Printf("PTRACE_SETSIGINFO %s", buf.GetData());
237                 break;
238             }
239             case PTRACE_SETREGSET:
240             {
241                 // Extract iov_base from data, which is a pointer to the struct IOVEC
242                 DisplayBytes(buf, *(void **)data, data_size);
243                 verbose_log->Printf("PTRACE_SETREGSET %s", buf.GetData());
244                 break;
245             }
246             default:
247             {
248             }
249             }
250         }
251     }
252 
253     // Wrapper for ptrace to catch errors and log calls.
254     // Note that ptrace sets errno on error because -1 can be a valid result (i.e. for PTRACE_PEEK*)
255     long
256     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size,
257             const char* reqName, const char* file, int line)
258     {
259         long int result;
260 
261         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_PTRACE));
262 
263         PtraceDisplayBytes(req, data, data_size);
264 
265         errno = 0;
266         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
267             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
268         else
269             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
270 
271         if (log)
272             log->Printf("ptrace(%s, %" PRIu64 ", %p, %p, %zu)=%lX called from file %s line %d",
273                     reqName, pid, addr, data, data_size, result, file, line);
274 
275         PtraceDisplayBytes(req, data, data_size);
276 
277         if (log && errno != 0)
278         {
279             const char* str;
280             switch (errno)
281             {
282             case ESRCH:  str = "ESRCH"; break;
283             case EINVAL: str = "EINVAL"; break;
284             case EBUSY:  str = "EBUSY"; break;
285             case EPERM:  str = "EPERM"; break;
286             default:     str = "<unknown>";
287             }
288             log->Printf("ptrace() failed; errno=%d (%s)", errno, str);
289         }
290 
291         return result;
292     }
293 
294 #ifdef LLDB_CONFIGURATION_BUILDANDINTEGRATION
295     // Wrapper for ptrace when logging is not required.
296     // Sets errno to 0 prior to calling ptrace.
297     long
298     PtraceWrapper(int req, lldb::pid_t pid, void *addr, void *data, size_t data_size)
299     {
300         long result = 0;
301         errno = 0;
302         if (req == PTRACE_GETREGSET || req == PTRACE_SETREGSET)
303             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), *(unsigned int *)addr, data);
304         else
305             result = ptrace(static_cast<__ptrace_request>(req), static_cast< ::pid_t>(pid), addr, data);
306         return result;
307     }
308 #endif
309 
310     //------------------------------------------------------------------------------
311     // Static implementations of NativeProcessLinux::ReadMemory and
312     // NativeProcessLinux::WriteMemory.  This enables mutual recursion between these
313     // functions without needed to go thru the thread funnel.
314 
315     static lldb::addr_t
316     DoReadMemory (
317         lldb::pid_t pid,
318         lldb::addr_t vm_addr,
319         void *buf,
320         lldb::addr_t size,
321         Error &error)
322     {
323         // ptrace word size is determined by the host, not the child
324         static const unsigned word_size = sizeof(void*);
325         unsigned char *dst = static_cast<unsigned char*>(buf);
326         lldb::addr_t bytes_read;
327         lldb::addr_t remainder;
328         long data;
329 
330         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
331         if (log)
332             ProcessPOSIXLog::IncNestLevel();
333         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
334             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %d, %p, %p, %zd, _)", __FUNCTION__,
335                     pid, word_size, (void*)vm_addr, buf, size);
336 
337         assert(sizeof(data) >= word_size);
338         for (bytes_read = 0; bytes_read < size; bytes_read += remainder)
339         {
340             errno = 0;
341             data = PTRACE(PTRACE_PEEKDATA, pid, (void*)vm_addr, NULL, 0);
342             if (errno)
343             {
344                 error.SetErrorToErrno();
345                 if (log)
346                     ProcessPOSIXLog::DecNestLevel();
347                 return bytes_read;
348             }
349 
350             remainder = size - bytes_read;
351             remainder = remainder > word_size ? word_size : remainder;
352 
353             // Copy the data into our buffer
354             for (unsigned i = 0; i < remainder; ++i)
355                 dst[i] = ((data >> i*8) & 0xFF);
356 
357             if (log && ProcessPOSIXLog::AtTopNestLevel() &&
358                     (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
359                             (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
360                                     size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
361             {
362                 uintptr_t print_dst = 0;
363                 // Format bytes from data by moving into print_dst for log output
364                 for (unsigned i = 0; i < remainder; ++i)
365                     print_dst |= (((data >> i*8) & 0xFF) << i*8);
366                 log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
367                         (void*)vm_addr, print_dst, (unsigned long)data);
368             }
369 
370             vm_addr += word_size;
371             dst += word_size;
372         }
373 
374         if (log)
375             ProcessPOSIXLog::DecNestLevel();
376         return bytes_read;
377     }
378 
379     static lldb::addr_t
380     DoWriteMemory(
381         lldb::pid_t pid,
382         lldb::addr_t vm_addr,
383         const void *buf,
384         lldb::addr_t size,
385         Error &error)
386     {
387         // ptrace word size is determined by the host, not the child
388         static const unsigned word_size = sizeof(void*);
389         const unsigned char *src = static_cast<const unsigned char*>(buf);
390         lldb::addr_t bytes_written = 0;
391         lldb::addr_t remainder;
392 
393         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_ALL));
394         if (log)
395             ProcessPOSIXLog::IncNestLevel();
396         if (log && ProcessPOSIXLog::AtTopNestLevel() && log->GetMask().Test(POSIX_LOG_MEMORY))
397             log->Printf ("NativeProcessLinux::%s(%" PRIu64 ", %u, %p, %p, %" PRIu64 ")", __FUNCTION__,
398                     pid, word_size, (void*)vm_addr, buf, size);
399 
400         for (bytes_written = 0; bytes_written < size; bytes_written += remainder)
401         {
402             remainder = size - bytes_written;
403             remainder = remainder > word_size ? word_size : remainder;
404 
405             if (remainder == word_size)
406             {
407                 unsigned long data = 0;
408                 assert(sizeof(data) >= word_size);
409                 for (unsigned i = 0; i < word_size; ++i)
410                     data |= (unsigned long)src[i] << i*8;
411 
412                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
413                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
414                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
415                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
416                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
417                             (void*)vm_addr, *(unsigned long*)src, data);
418 
419                 if (PTRACE(PTRACE_POKEDATA, pid, (void*)vm_addr, (void*)data, 0))
420                 {
421                     error.SetErrorToErrno();
422                     if (log)
423                         ProcessPOSIXLog::DecNestLevel();
424                     return bytes_written;
425                 }
426             }
427             else
428             {
429                 unsigned char buff[8];
430                 if (DoReadMemory(pid, vm_addr,
431                                 buff, word_size, error) != word_size)
432                 {
433                     if (log)
434                         ProcessPOSIXLog::DecNestLevel();
435                     return bytes_written;
436                 }
437 
438                 memcpy(buff, src, remainder);
439 
440                 if (DoWriteMemory(pid, vm_addr,
441                                 buff, word_size, error) != word_size)
442                 {
443                     if (log)
444                         ProcessPOSIXLog::DecNestLevel();
445                     return bytes_written;
446                 }
447 
448                 if (log && ProcessPOSIXLog::AtTopNestLevel() &&
449                         (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_LONG) ||
450                                 (log->GetMask().Test(POSIX_LOG_MEMORY_DATA_SHORT) &&
451                                         size <= POSIX_LOG_MEMORY_SHORT_BYTES)))
452                     log->Printf ("NativeProcessLinux::%s() [%p]:0x%lx (0x%lx)", __FUNCTION__,
453                             (void*)vm_addr, *(unsigned long*)src, *(unsigned long*)buff);
454             }
455 
456             vm_addr += word_size;
457             src += word_size;
458         }
459         if (log)
460             ProcessPOSIXLog::DecNestLevel();
461         return bytes_written;
462     }
463 
464     //------------------------------------------------------------------------------
465     /// @class Operation
466     /// @brief Represents a NativeProcessLinux operation.
467     ///
468     /// Under Linux, it is not possible to ptrace() from any other thread but the
469     /// one that spawned or attached to the process from the start.  Therefore, when
470     /// a NativeProcessLinux is asked to deliver or change the state of an inferior
471     /// process the operation must be "funneled" to a specific thread to perform the
472     /// task.  The Operation class provides an abstract base for all services the
473     /// NativeProcessLinux must perform via the single virtual function Execute, thus
474     /// encapsulating the code that needs to run in the privileged context.
475     class Operation
476     {
477     public:
478         Operation () : m_error() { }
479 
480         virtual
481         ~Operation() {}
482 
483         virtual void
484         Execute (NativeProcessLinux *process) = 0;
485 
486         const Error &
487         GetError () const { return m_error; }
488 
489     protected:
490         Error m_error;
491     };
492 
493     //------------------------------------------------------------------------------
494     /// @class ReadOperation
495     /// @brief Implements NativeProcessLinux::ReadMemory.
496     class ReadOperation : public Operation
497     {
498     public:
499         ReadOperation (
500             lldb::addr_t addr,
501             void *buff,
502             lldb::addr_t size,
503             lldb::addr_t &result) :
504             Operation (),
505             m_addr (addr),
506             m_buff (buff),
507             m_size (size),
508             m_result (result)
509             {
510             }
511 
512         void Execute (NativeProcessLinux *process) override;
513 
514     private:
515         lldb::addr_t m_addr;
516         void *m_buff;
517         lldb::addr_t m_size;
518         lldb::addr_t &m_result;
519     };
520 
521     void
522     ReadOperation::Execute (NativeProcessLinux *process)
523     {
524         m_result = DoReadMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
525     }
526 
527     //------------------------------------------------------------------------------
528     /// @class WriteOperation
529     /// @brief Implements NativeProcessLinux::WriteMemory.
530     class WriteOperation : public Operation
531     {
532     public:
533         WriteOperation (
534             lldb::addr_t addr,
535             const void *buff,
536             lldb::addr_t size,
537             lldb::addr_t &result) :
538             Operation (),
539             m_addr (addr),
540             m_buff (buff),
541             m_size (size),
542             m_result (result)
543             {
544             }
545 
546         void Execute (NativeProcessLinux *process) override;
547 
548     private:
549         lldb::addr_t m_addr;
550         const void *m_buff;
551         lldb::addr_t m_size;
552         lldb::addr_t &m_result;
553     };
554 
555     void
556     WriteOperation::Execute(NativeProcessLinux *process)
557     {
558         m_result = DoWriteMemory (process->GetID (), m_addr, m_buff, m_size, m_error);
559     }
560 
561     //------------------------------------------------------------------------------
562     /// @class ReadRegOperation
563     /// @brief Implements NativeProcessLinux::ReadRegisterValue.
564     class ReadRegOperation : public Operation
565     {
566     public:
567         ReadRegOperation(lldb::tid_t tid, uint32_t offset, const char *reg_name,
568                 RegisterValue &value, bool &result)
569             : m_tid(tid), m_offset(static_cast<uintptr_t> (offset)), m_reg_name(reg_name),
570               m_value(value), m_result(result)
571             { }
572 
573         void Execute(NativeProcessLinux *monitor);
574 
575     private:
576         lldb::tid_t m_tid;
577         uintptr_t m_offset;
578         const char *m_reg_name;
579         RegisterValue &m_value;
580         bool &m_result;
581     };
582 
583     void
584     ReadRegOperation::Execute(NativeProcessLinux *monitor)
585     {
586 #if defined (__arm64__) || defined (__aarch64__)
587         if (m_offset > sizeof(struct user_pt_regs))
588         {
589             uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
590             if (offset > sizeof(struct user_fpsimd_state))
591             {
592                 m_result = false;
593             }
594             else
595             {
596                 elf_fpregset_t regs;
597                 int regset = NT_FPREGSET;
598                 struct iovec ioVec;
599 
600                 ioVec.iov_base = &regs;
601                 ioVec.iov_len = sizeof regs;
602                 if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
603                     m_result = false;
604                 else
605                 {
606                     lldb_private::ArchSpec arch;
607                     if (monitor->GetArchitecture(arch))
608                     {
609                         m_result = true;
610                         m_value.SetBytes((void *)(((unsigned char *)(&regs)) + offset), 16, arch.GetByteOrder());
611                     }
612                     else
613                         m_result = false;
614                 }
615             }
616         }
617         else
618         {
619             elf_gregset_t regs;
620             int regset = NT_PRSTATUS;
621             struct iovec ioVec;
622 
623             ioVec.iov_base = &regs;
624             ioVec.iov_len = sizeof regs;
625             if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
626                 m_result = false;
627             else
628             {
629                 lldb_private::ArchSpec arch;
630                 if (monitor->GetArchitecture(arch))
631                 {
632                     m_result = true;
633                     m_value.SetBytes((void *)(((unsigned char *)(regs)) + m_offset), 8, arch.GetByteOrder());
634                 } else
635                     m_result = false;
636             }
637         }
638 #else
639         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
640 
641         // Set errno to zero so that we can detect a failed peek.
642         errno = 0;
643         lldb::addr_t data = PTRACE(PTRACE_PEEKUSER, m_tid, (void*)m_offset, NULL, 0);
644         if (errno)
645             m_result = false;
646         else
647         {
648             m_value = data;
649             m_result = true;
650         }
651         if (log)
652             log->Printf ("NativeProcessLinux::%s() reg %s: 0x%" PRIx64, __FUNCTION__,
653                     m_reg_name, data);
654 #endif
655     }
656 
657     //------------------------------------------------------------------------------
658     /// @class WriteRegOperation
659     /// @brief Implements NativeProcessLinux::WriteRegisterValue.
660     class WriteRegOperation : public Operation
661     {
662     public:
663         WriteRegOperation(lldb::tid_t tid, unsigned offset, const char *reg_name,
664                 const RegisterValue &value, bool &result)
665             : m_tid(tid), m_offset(offset), m_reg_name(reg_name),
666               m_value(value), m_result(result)
667             { }
668 
669         void Execute(NativeProcessLinux *monitor);
670 
671     private:
672         lldb::tid_t m_tid;
673         uintptr_t m_offset;
674         const char *m_reg_name;
675         const RegisterValue &m_value;
676         bool &m_result;
677     };
678 
679     void
680     WriteRegOperation::Execute(NativeProcessLinux *monitor)
681     {
682 #if defined (__arm64__) || defined (__aarch64__)
683         if (m_offset > sizeof(struct user_pt_regs))
684         {
685             uintptr_t offset = m_offset - sizeof(struct user_pt_regs);
686             if (offset > sizeof(struct user_fpsimd_state))
687             {
688                 m_result = false;
689             }
690             else
691             {
692                 elf_fpregset_t regs;
693                 int regset = NT_FPREGSET;
694                 struct iovec ioVec;
695 
696                 ioVec.iov_base = &regs;
697                 ioVec.iov_len = sizeof regs;
698                 if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
699                     m_result = false;
700                 else
701                 {
702                     ::memcpy((void *)(((unsigned char *)(&regs)) + offset), m_value.GetBytes(), 16);
703                     if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
704                         m_result = false;
705                     else
706                         m_result = true;
707                 }
708             }
709         }
710         else
711         {
712             elf_gregset_t regs;
713             int regset = NT_PRSTATUS;
714             struct iovec ioVec;
715 
716             ioVec.iov_base = &regs;
717             ioVec.iov_len = sizeof regs;
718             if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
719                 m_result = false;
720             else
721             {
722                 ::memcpy((void *)(((unsigned char *)(&regs)) + m_offset), m_value.GetBytes(), 8);
723                 if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, sizeof regs) < 0)
724                     m_result = false;
725                 else
726                     m_result = true;
727             }
728         }
729 #else
730         void* buf;
731         Log *log (ProcessPOSIXLog::GetLogIfAllCategoriesSet (POSIX_LOG_REGISTERS));
732 
733         buf = (void*) m_value.GetAsUInt64();
734 
735         if (log)
736             log->Printf ("NativeProcessLinux::%s() reg %s: %p", __FUNCTION__, m_reg_name, buf);
737         if (PTRACE(PTRACE_POKEUSER, m_tid, (void*)m_offset, buf, 0))
738             m_result = false;
739         else
740             m_result = true;
741 #endif
742     }
743 
744     //------------------------------------------------------------------------------
745     /// @class ReadGPROperation
746     /// @brief Implements NativeProcessLinux::ReadGPR.
747     class ReadGPROperation : public Operation
748     {
749     public:
750         ReadGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
751             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
752             { }
753 
754         void Execute(NativeProcessLinux *monitor);
755 
756     private:
757         lldb::tid_t m_tid;
758         void *m_buf;
759         size_t m_buf_size;
760         bool &m_result;
761     };
762 
763     void
764     ReadGPROperation::Execute(NativeProcessLinux *monitor)
765     {
766 #if defined (__arm64__) || defined (__aarch64__)
767         int regset = NT_PRSTATUS;
768         struct iovec ioVec;
769 
770         ioVec.iov_base = m_buf;
771         ioVec.iov_len = m_buf_size;
772         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
773             m_result = false;
774         else
775             m_result = true;
776 #else
777         if (PTRACE(PTRACE_GETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
778             m_result = false;
779         else
780             m_result = true;
781 #endif
782     }
783 
784     //------------------------------------------------------------------------------
785     /// @class ReadFPROperation
786     /// @brief Implements NativeProcessLinux::ReadFPR.
787     class ReadFPROperation : public Operation
788     {
789     public:
790         ReadFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
791             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), 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         bool &m_result;
801     };
802 
803     void
804     ReadFPROperation::Execute(NativeProcessLinux *monitor)
805     {
806 #if defined (__arm64__) || defined (__aarch64__)
807         int regset = NT_FPREGSET;
808         struct iovec ioVec;
809 
810         ioVec.iov_base = m_buf;
811         ioVec.iov_len = m_buf_size;
812         if (PTRACE(PTRACE_GETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
813             m_result = false;
814         else
815             m_result = true;
816 #else
817         if (PTRACE(PTRACE_GETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
818             m_result = false;
819         else
820             m_result = true;
821 #endif
822     }
823 
824     //------------------------------------------------------------------------------
825     /// @class ReadRegisterSetOperation
826     /// @brief Implements NativeProcessLinux::ReadRegisterSet.
827     class ReadRegisterSetOperation : public Operation
828     {
829     public:
830         ReadRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
831             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
832             { }
833 
834         void Execute(NativeProcessLinux *monitor);
835 
836     private:
837         lldb::tid_t m_tid;
838         void *m_buf;
839         size_t m_buf_size;
840         const unsigned int m_regset;
841         bool &m_result;
842     };
843 
844     void
845     ReadRegisterSetOperation::Execute(NativeProcessLinux *monitor)
846     {
847         if (PTRACE(PTRACE_GETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
848             m_result = false;
849         else
850             m_result = true;
851     }
852 
853     //------------------------------------------------------------------------------
854     /// @class WriteGPROperation
855     /// @brief Implements NativeProcessLinux::WriteGPR.
856     class WriteGPROperation : public Operation
857     {
858     public:
859         WriteGPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
860             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
861             { }
862 
863         void Execute(NativeProcessLinux *monitor);
864 
865     private:
866         lldb::tid_t m_tid;
867         void *m_buf;
868         size_t m_buf_size;
869         bool &m_result;
870     };
871 
872     void
873     WriteGPROperation::Execute(NativeProcessLinux *monitor)
874     {
875 #if defined (__arm64__) || defined (__aarch64__)
876         int regset = NT_PRSTATUS;
877         struct iovec ioVec;
878 
879         ioVec.iov_base = m_buf;
880         ioVec.iov_len = m_buf_size;
881         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
882             m_result = false;
883         else
884             m_result = true;
885 #else
886         if (PTRACE(PTRACE_SETREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
887             m_result = false;
888         else
889             m_result = true;
890 #endif
891     }
892 
893     //------------------------------------------------------------------------------
894     /// @class WriteFPROperation
895     /// @brief Implements NativeProcessLinux::WriteFPR.
896     class WriteFPROperation : public Operation
897     {
898     public:
899         WriteFPROperation(lldb::tid_t tid, void *buf, size_t buf_size, bool &result)
900             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_result(result)
901             { }
902 
903         void Execute(NativeProcessLinux *monitor);
904 
905     private:
906         lldb::tid_t m_tid;
907         void *m_buf;
908         size_t m_buf_size;
909         bool &m_result;
910     };
911 
912     void
913     WriteFPROperation::Execute(NativeProcessLinux *monitor)
914     {
915 #if defined (__arm64__) || defined (__aarch64__)
916         int regset = NT_FPREGSET;
917         struct iovec ioVec;
918 
919         ioVec.iov_base = m_buf;
920         ioVec.iov_len = m_buf_size;
921         if (PTRACE(PTRACE_SETREGSET, m_tid, &regset, &ioVec, m_buf_size) < 0)
922             m_result = false;
923         else
924             m_result = true;
925 #else
926         if (PTRACE(PTRACE_SETFPREGS, m_tid, NULL, m_buf, m_buf_size) < 0)
927             m_result = false;
928         else
929             m_result = true;
930 #endif
931     }
932 
933     //------------------------------------------------------------------------------
934     /// @class WriteRegisterSetOperation
935     /// @brief Implements NativeProcessLinux::WriteRegisterSet.
936     class WriteRegisterSetOperation : public Operation
937     {
938     public:
939         WriteRegisterSetOperation(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset, bool &result)
940             : m_tid(tid), m_buf(buf), m_buf_size(buf_size), m_regset(regset), m_result(result)
941             { }
942 
943         void Execute(NativeProcessLinux *monitor);
944 
945     private:
946         lldb::tid_t m_tid;
947         void *m_buf;
948         size_t m_buf_size;
949         const unsigned int m_regset;
950         bool &m_result;
951     };
952 
953     void
954     WriteRegisterSetOperation::Execute(NativeProcessLinux *monitor)
955     {
956         if (PTRACE(PTRACE_SETREGSET, m_tid, (void *)&m_regset, m_buf, m_buf_size) < 0)
957             m_result = false;
958         else
959             m_result = true;
960     }
961 
962     //------------------------------------------------------------------------------
963     /// @class ResumeOperation
964     /// @brief Implements NativeProcessLinux::Resume.
965     class ResumeOperation : public Operation
966     {
967     public:
968         ResumeOperation(lldb::tid_t tid, uint32_t signo, bool &result) :
969             m_tid(tid), m_signo(signo), m_result(result) { }
970 
971         void Execute(NativeProcessLinux *monitor);
972 
973     private:
974         lldb::tid_t m_tid;
975         uint32_t m_signo;
976         bool &m_result;
977     };
978 
979     void
980     ResumeOperation::Execute(NativeProcessLinux *monitor)
981     {
982         intptr_t data = 0;
983 
984         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
985             data = m_signo;
986 
987         if (PTRACE(PTRACE_CONT, m_tid, NULL, (void*)data, 0))
988         {
989             Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
990 
991             if (log)
992                 log->Printf ("ResumeOperation (%"  PRIu64 ") failed: %s", m_tid, strerror(errno));
993             m_result = false;
994         }
995         else
996             m_result = true;
997     }
998 
999     //------------------------------------------------------------------------------
1000     /// @class SingleStepOperation
1001     /// @brief Implements NativeProcessLinux::SingleStep.
1002     class SingleStepOperation : public Operation
1003     {
1004     public:
1005         SingleStepOperation(lldb::tid_t tid, uint32_t signo, bool &result)
1006             : m_tid(tid), m_signo(signo), m_result(result) { }
1007 
1008         void Execute(NativeProcessLinux *monitor);
1009 
1010     private:
1011         lldb::tid_t m_tid;
1012         uint32_t m_signo;
1013         bool &m_result;
1014     };
1015 
1016     void
1017     SingleStepOperation::Execute(NativeProcessLinux *monitor)
1018     {
1019         intptr_t data = 0;
1020 
1021         if (m_signo != LLDB_INVALID_SIGNAL_NUMBER)
1022             data = m_signo;
1023 
1024         if (PTRACE(PTRACE_SINGLESTEP, m_tid, NULL, (void*)data, 0))
1025             m_result = false;
1026         else
1027             m_result = true;
1028     }
1029 
1030     //------------------------------------------------------------------------------
1031     /// @class SiginfoOperation
1032     /// @brief Implements NativeProcessLinux::GetSignalInfo.
1033     class SiginfoOperation : public Operation
1034     {
1035     public:
1036         SiginfoOperation(lldb::tid_t tid, void *info, bool &result, int &ptrace_err)
1037             : m_tid(tid), m_info(info), m_result(result), m_err(ptrace_err) { }
1038 
1039         void Execute(NativeProcessLinux *monitor);
1040 
1041     private:
1042         lldb::tid_t m_tid;
1043         void *m_info;
1044         bool &m_result;
1045         int &m_err;
1046     };
1047 
1048     void
1049     SiginfoOperation::Execute(NativeProcessLinux *monitor)
1050     {
1051         if (PTRACE(PTRACE_GETSIGINFO, m_tid, NULL, m_info, 0)) {
1052             m_result = false;
1053             m_err = errno;
1054         }
1055         else
1056             m_result = true;
1057     }
1058 
1059     //------------------------------------------------------------------------------
1060     /// @class EventMessageOperation
1061     /// @brief Implements NativeProcessLinux::GetEventMessage.
1062     class EventMessageOperation : public Operation
1063     {
1064     public:
1065         EventMessageOperation(lldb::tid_t tid, unsigned long *message, bool &result)
1066             : m_tid(tid), m_message(message), m_result(result) { }
1067 
1068         void Execute(NativeProcessLinux *monitor);
1069 
1070     private:
1071         lldb::tid_t m_tid;
1072         unsigned long *m_message;
1073         bool &m_result;
1074     };
1075 
1076     void
1077     EventMessageOperation::Execute(NativeProcessLinux *monitor)
1078     {
1079         if (PTRACE(PTRACE_GETEVENTMSG, m_tid, NULL, m_message, 0))
1080             m_result = false;
1081         else
1082             m_result = true;
1083     }
1084 
1085     class DetachOperation : public Operation
1086     {
1087     public:
1088         DetachOperation(lldb::tid_t tid, Error &result) : m_tid(tid), m_error(result) { }
1089 
1090         void Execute(NativeProcessLinux *monitor);
1091 
1092     private:
1093         lldb::tid_t m_tid;
1094         Error &m_error;
1095     };
1096 
1097     void
1098     DetachOperation::Execute(NativeProcessLinux *monitor)
1099     {
1100         if (ptrace(PT_DETACH, m_tid, NULL, 0) < 0)
1101             m_error.SetErrorToErrno();
1102     }
1103 
1104 }
1105 
1106 using namespace lldb_private;
1107 
1108 // Simple helper function to ensure flags are enabled on the given file
1109 // descriptor.
1110 static bool
1111 EnsureFDFlags(int fd, int flags, Error &error)
1112 {
1113     int status;
1114 
1115     if ((status = fcntl(fd, F_GETFL)) == -1)
1116     {
1117         error.SetErrorToErrno();
1118         return false;
1119     }
1120 
1121     if (fcntl(fd, F_SETFL, status | flags) == -1)
1122     {
1123         error.SetErrorToErrno();
1124         return false;
1125     }
1126 
1127     return true;
1128 }
1129 
1130 NativeProcessLinux::OperationArgs::OperationArgs(NativeProcessLinux *monitor)
1131     : m_monitor(monitor)
1132 {
1133     sem_init(&m_semaphore, 0, 0);
1134 }
1135 
1136 NativeProcessLinux::OperationArgs::~OperationArgs()
1137 {
1138     sem_destroy(&m_semaphore);
1139 }
1140 
1141 NativeProcessLinux::LaunchArgs::LaunchArgs(NativeProcessLinux *monitor,
1142                                        lldb_private::Module *module,
1143                                        char const **argv,
1144                                        char const **envp,
1145                                        const std::string &stdin_path,
1146                                        const std::string &stdout_path,
1147                                        const std::string &stderr_path,
1148                                        const char *working_dir,
1149                                        const lldb_private::ProcessLaunchInfo &launch_info)
1150     : OperationArgs(monitor),
1151       m_module(module),
1152       m_argv(argv),
1153       m_envp(envp),
1154       m_stdin_path(stdin_path),
1155       m_stdout_path(stdout_path),
1156       m_stderr_path(stderr_path),
1157       m_working_dir(working_dir),
1158       m_launch_info(launch_info)
1159 {
1160 }
1161 
1162 NativeProcessLinux::LaunchArgs::~LaunchArgs()
1163 { }
1164 
1165 NativeProcessLinux::AttachArgs::AttachArgs(NativeProcessLinux *monitor,
1166                                        lldb::pid_t pid)
1167     : OperationArgs(monitor), m_pid(pid) { }
1168 
1169 NativeProcessLinux::AttachArgs::~AttachArgs()
1170 { }
1171 
1172 // -----------------------------------------------------------------------------
1173 // Public Static Methods
1174 // -----------------------------------------------------------------------------
1175 
1176 lldb_private::Error
1177 NativeProcessLinux::LaunchProcess (
1178     lldb_private::Module *exe_module,
1179     lldb_private::ProcessLaunchInfo &launch_info,
1180     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1181     NativeProcessProtocolSP &native_process_sp)
1182 {
1183     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1184 
1185     Error error;
1186 
1187     // Verify the working directory is valid if one was specified.
1188     const char* working_dir = launch_info.GetWorkingDirectory ();
1189     if (working_dir)
1190     {
1191       FileSpec working_dir_fs (working_dir, true);
1192       if (!working_dir_fs || working_dir_fs.GetFileType () != FileSpec::eFileTypeDirectory)
1193       {
1194           error.SetErrorStringWithFormat ("No such file or directory: %s", working_dir);
1195           return error;
1196       }
1197     }
1198 
1199     const lldb_private::FileAction *file_action;
1200 
1201     // Default of NULL will mean to use existing open file descriptors.
1202     std::string stdin_path;
1203     std::string stdout_path;
1204     std::string stderr_path;
1205 
1206     file_action = launch_info.GetFileActionForFD (STDIN_FILENO);
1207     if (file_action)
1208         stdin_path = file_action->GetPath ();
1209 
1210     file_action = launch_info.GetFileActionForFD (STDOUT_FILENO);
1211     if (file_action)
1212         stdout_path = file_action->GetPath ();
1213 
1214     file_action = launch_info.GetFileActionForFD (STDERR_FILENO);
1215     if (file_action)
1216         stderr_path = file_action->GetPath ();
1217 
1218     if (log)
1219     {
1220         if (!stdin_path.empty ())
1221             log->Printf ("NativeProcessLinux::%s setting STDIN to '%s'", __FUNCTION__, stdin_path.c_str ());
1222         else
1223             log->Printf ("NativeProcessLinux::%s leaving STDIN as is", __FUNCTION__);
1224 
1225         if (!stdout_path.empty ())
1226             log->Printf ("NativeProcessLinux::%s setting STDOUT to '%s'", __FUNCTION__, stdout_path.c_str ());
1227         else
1228             log->Printf ("NativeProcessLinux::%s leaving STDOUT as is", __FUNCTION__);
1229 
1230         if (!stderr_path.empty ())
1231             log->Printf ("NativeProcessLinux::%s setting STDERR to '%s'", __FUNCTION__, stderr_path.c_str ());
1232         else
1233             log->Printf ("NativeProcessLinux::%s leaving STDERR as is", __FUNCTION__);
1234     }
1235 
1236     // Create the NativeProcessLinux in launch mode.
1237     native_process_sp.reset (new NativeProcessLinux ());
1238 
1239     if (log)
1240     {
1241         int i = 0;
1242         for (const char **args = launch_info.GetArguments ().GetConstArgumentVector (); *args; ++args, ++i)
1243         {
1244             log->Printf ("NativeProcessLinux::%s arg %d: \"%s\"", __FUNCTION__, i, *args ? *args : "nullptr");
1245             ++i;
1246         }
1247     }
1248 
1249     if (!native_process_sp->RegisterNativeDelegate (native_delegate))
1250     {
1251         native_process_sp.reset ();
1252         error.SetErrorStringWithFormat ("failed to register the native delegate");
1253         return error;
1254     }
1255 
1256     reinterpret_cast<NativeProcessLinux*> (native_process_sp.get ())->LaunchInferior (
1257             exe_module,
1258             launch_info.GetArguments ().GetConstArgumentVector (),
1259             launch_info.GetEnvironmentEntries ().GetConstArgumentVector (),
1260             stdin_path,
1261             stdout_path,
1262             stderr_path,
1263             working_dir,
1264             launch_info,
1265             error);
1266 
1267     if (error.Fail ())
1268     {
1269         native_process_sp.reset ();
1270         if (log)
1271             log->Printf ("NativeProcessLinux::%s failed to launch process: %s", __FUNCTION__, error.AsCString ());
1272         return error;
1273     }
1274 
1275     launch_info.SetProcessID (native_process_sp->GetID ());
1276 
1277     return error;
1278 }
1279 
1280 lldb_private::Error
1281 NativeProcessLinux::AttachToProcess (
1282     lldb::pid_t pid,
1283     lldb_private::NativeProcessProtocol::NativeDelegate &native_delegate,
1284     NativeProcessProtocolSP &native_process_sp)
1285 {
1286     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1287     if (log && log->GetMask ().Test (POSIX_LOG_VERBOSE))
1288         log->Printf ("NativeProcessLinux::%s(pid = %" PRIi64 ")", __FUNCTION__, pid);
1289 
1290     // Grab the current platform architecture.  This should be Linux,
1291     // since this code is only intended to run on a Linux host.
1292     PlatformSP platform_sp (Platform::GetHostPlatform ());
1293     if (!platform_sp)
1294         return Error("failed to get a valid default platform");
1295 
1296     // Retrieve the architecture for the running process.
1297     ArchSpec process_arch;
1298     Error error = ResolveProcessArchitecture (pid, *platform_sp.get (), process_arch);
1299     if (!error.Success ())
1300         return error;
1301 
1302     std::shared_ptr<NativeProcessLinux> native_process_linux_sp (new NativeProcessLinux ());
1303 
1304     if (!native_process_linux_sp->RegisterNativeDelegate (native_delegate))
1305     {
1306         error.SetErrorStringWithFormat ("failed to register the native delegate");
1307         return error;
1308     }
1309 
1310     native_process_linux_sp->AttachToInferior (pid, error);
1311     if (!error.Success ())
1312         return error;
1313 
1314     native_process_sp = native_process_linux_sp;
1315     return error;
1316 }
1317 
1318 // -----------------------------------------------------------------------------
1319 // Public Instance Methods
1320 // -----------------------------------------------------------------------------
1321 
1322 NativeProcessLinux::NativeProcessLinux () :
1323     NativeProcessProtocol (LLDB_INVALID_PROCESS_ID),
1324     m_arch (),
1325     m_operation (nullptr),
1326     m_operation_mutex (),
1327     m_operation_pending (),
1328     m_operation_done (),
1329     m_wait_for_stop_tids (),
1330     m_wait_for_stop_tids_mutex (),
1331     m_wait_for_group_stop_tids (),
1332     m_group_stop_signal_tid (LLDB_INVALID_THREAD_ID),
1333     m_group_stop_signal (LLDB_INVALID_SIGNAL_NUMBER),
1334     m_wait_for_group_stop_tids_mutex (),
1335     m_supports_mem_region (eLazyBoolCalculate),
1336     m_mem_region_cache (),
1337     m_mem_region_cache_mutex ()
1338 {
1339 }
1340 
1341 //------------------------------------------------------------------------------
1342 /// The basic design of the NativeProcessLinux is built around two threads.
1343 ///
1344 /// One thread (@see SignalThread) simply blocks on a call to waitpid() looking
1345 /// for changes in the debugee state.  When a change is detected a
1346 /// ProcessMessage is sent to the associated ProcessLinux instance.  This thread
1347 /// "drives" state changes in the debugger.
1348 ///
1349 /// The second thread (@see OperationThread) is responsible for two things 1)
1350 /// launching or attaching to the inferior process, and then 2) servicing
1351 /// operations such as register reads/writes, stepping, etc.  See the comments
1352 /// on the Operation class for more info as to why this is needed.
1353 void
1354 NativeProcessLinux::LaunchInferior (
1355     Module *module,
1356     const char *argv[],
1357     const char *envp[],
1358     const std::string &stdin_path,
1359     const std::string &stdout_path,
1360     const std::string &stderr_path,
1361     const char *working_dir,
1362     const lldb_private::ProcessLaunchInfo &launch_info,
1363     lldb_private::Error &error)
1364 {
1365     if (module)
1366         m_arch = module->GetArchitecture ();
1367 
1368     SetState(eStateLaunching);
1369 
1370     std::unique_ptr<LaunchArgs> args(
1371         new LaunchArgs(
1372             this, module, argv, envp,
1373             stdin_path, stdout_path, stderr_path,
1374             working_dir, launch_info));
1375 
1376     sem_init(&m_operation_pending, 0, 0);
1377     sem_init(&m_operation_done, 0, 0);
1378 
1379     StartLaunchOpThread(args.get(), error);
1380     if (!error.Success())
1381         return;
1382 
1383 WAIT_AGAIN:
1384     // Wait for the operation thread to initialize.
1385     if (sem_wait(&args->m_semaphore))
1386     {
1387         if (errno == EINTR)
1388             goto WAIT_AGAIN;
1389         else
1390         {
1391             error.SetErrorToErrno();
1392             return;
1393         }
1394     }
1395 
1396     // Check that the launch was a success.
1397     if (!args->m_error.Success())
1398     {
1399         StopOpThread();
1400         error = args->m_error;
1401         return;
1402     }
1403 
1404     // Finally, start monitoring the child process for change in state.
1405     m_monitor_thread = Host::StartMonitoringChildProcess(
1406         NativeProcessLinux::MonitorCallback, this, GetID(), true);
1407     if (!m_monitor_thread.IsJoinable())
1408     {
1409         error.SetErrorToGenericError();
1410         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1411         return;
1412     }
1413 }
1414 
1415 void
1416 NativeProcessLinux::AttachToInferior (lldb::pid_t pid, lldb_private::Error &error)
1417 {
1418     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1419     if (log)
1420         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ")", __FUNCTION__, pid);
1421 
1422     // We can use the Host for everything except the ResolveExecutable portion.
1423     PlatformSP platform_sp = Platform::GetHostPlatform ();
1424     if (!platform_sp)
1425     {
1426         if (log)
1427             log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 "): no default platform set", __FUNCTION__, pid);
1428         error.SetErrorString ("no default platform available");
1429         return;
1430     }
1431 
1432     // Gather info about the process.
1433     ProcessInstanceInfo process_info;
1434     if (!platform_sp->GetProcessInfo (pid, process_info))
1435     {
1436         if (log)
1437             log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 "): failed to get process info", __FUNCTION__, pid);
1438         error.SetErrorString ("failed to get process info");
1439         return;
1440     }
1441 
1442     // Resolve the executable module
1443     ModuleSP exe_module_sp;
1444     FileSpecList executable_search_paths (Target::GetDefaultExecutableSearchPaths());
1445     ModuleSpec exe_module_spec(process_info.GetExecutableFile(), HostInfo::GetArchitecture());
1446     error = platform_sp->ResolveExecutable(exe_module_spec, exe_module_sp,
1447                                            executable_search_paths.GetSize() ? &executable_search_paths : NULL);
1448     if (!error.Success())
1449         return;
1450 
1451     // Set the architecture to the exe architecture.
1452     m_arch = exe_module_sp->GetArchitecture();
1453     if (log)
1454         log->Printf ("NativeProcessLinux::%s (pid = %" PRIi64 ") detected architecture %s", __FUNCTION__, pid, m_arch.GetArchitectureName ());
1455 
1456     m_pid = pid;
1457     SetState(eStateAttaching);
1458 
1459     sem_init (&m_operation_pending, 0, 0);
1460     sem_init (&m_operation_done, 0, 0);
1461 
1462     std::unique_ptr<AttachArgs> args (new AttachArgs (this, pid));
1463 
1464     StartAttachOpThread(args.get (), error);
1465     if (!error.Success ())
1466         return;
1467 
1468 WAIT_AGAIN:
1469     // Wait for the operation thread to initialize.
1470     if (sem_wait (&args->m_semaphore))
1471     {
1472         if (errno == EINTR)
1473             goto WAIT_AGAIN;
1474         else
1475         {
1476             error.SetErrorToErrno ();
1477             return;
1478         }
1479     }
1480 
1481     // Check that the attach was a success.
1482     if (!args->m_error.Success ())
1483     {
1484         StopOpThread ();
1485         error = args->m_error;
1486         return;
1487     }
1488 
1489     // Finally, start monitoring the child process for change in state.
1490     m_monitor_thread = Host::StartMonitoringChildProcess (
1491         NativeProcessLinux::MonitorCallback, this, GetID (), true);
1492     if (!m_monitor_thread.IsJoinable())
1493     {
1494         error.SetErrorToGenericError ();
1495         error.SetErrorString ("Process attach failed to create monitor thread for NativeProcessLinux::MonitorCallback.");
1496         return;
1497     }
1498 }
1499 
1500 NativeProcessLinux::~NativeProcessLinux()
1501 {
1502     StopMonitor();
1503 }
1504 
1505 //------------------------------------------------------------------------------
1506 // Thread setup and tear down.
1507 
1508 void
1509 NativeProcessLinux::StartLaunchOpThread(LaunchArgs *args, Error &error)
1510 {
1511     static const char *g_thread_name = "lldb.process.nativelinux.operation";
1512 
1513     if (m_operation_thread.IsJoinable())
1514         return;
1515 
1516     m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, LaunchOpThread, args, &error);
1517 }
1518 
1519 void *
1520 NativeProcessLinux::LaunchOpThread(void *arg)
1521 {
1522     LaunchArgs *args = static_cast<LaunchArgs*>(arg);
1523 
1524     if (!Launch(args)) {
1525         sem_post(&args->m_semaphore);
1526         return NULL;
1527     }
1528 
1529     ServeOperation(args);
1530     return NULL;
1531 }
1532 
1533 bool
1534 NativeProcessLinux::Launch(LaunchArgs *args)
1535 {
1536     assert (args && "null args");
1537     if (!args)
1538         return false;
1539 
1540     NativeProcessLinux *monitor = args->m_monitor;
1541     assert (monitor && "monitor is NULL");
1542     if (!monitor)
1543         return false;
1544 
1545     const char **argv = args->m_argv;
1546     const char **envp = args->m_envp;
1547     const char *working_dir = args->m_working_dir;
1548 
1549     lldb_utility::PseudoTerminal terminal;
1550     const size_t err_len = 1024;
1551     char err_str[err_len];
1552     lldb::pid_t pid;
1553     NativeThreadProtocolSP thread_sp;
1554 
1555     lldb::ThreadSP inferior;
1556 
1557     // Propagate the environment if one is not supplied.
1558     if (envp == NULL || envp[0] == NULL)
1559         envp = const_cast<const char **>(environ);
1560 
1561     if ((pid = terminal.Fork(err_str, err_len)) == static_cast<lldb::pid_t> (-1))
1562     {
1563         args->m_error.SetErrorToGenericError();
1564         args->m_error.SetErrorString("Process fork failed.");
1565         return false;
1566     }
1567 
1568     // Recognized child exit status codes.
1569     enum {
1570         ePtraceFailed = 1,
1571         eDupStdinFailed,
1572         eDupStdoutFailed,
1573         eDupStderrFailed,
1574         eChdirFailed,
1575         eExecFailed,
1576         eSetGidFailed
1577     };
1578 
1579     // Child process.
1580     if (pid == 0)
1581     {
1582         // FIXME consider opening a pipe between parent/child and have this forked child
1583         // send log info to parent re: launch status, in place of the log lines removed here.
1584 
1585         // Start tracing this child that is about to exec.
1586         if (PTRACE(PTRACE_TRACEME, 0, NULL, NULL, 0) < 0)
1587             exit(ePtraceFailed);
1588 
1589         // Do not inherit setgid powers.
1590         if (setgid(getgid()) != 0)
1591             exit(eSetGidFailed);
1592 
1593         // Attempt to have our own process group.
1594         if (setpgid(0, 0) != 0)
1595         {
1596             // FIXME log that this failed. This is common.
1597             // Don't allow this to prevent an inferior exec.
1598         }
1599 
1600         // Dup file descriptors if needed.
1601         if (!args->m_stdin_path.empty ())
1602             if (!DupDescriptor(args->m_stdin_path.c_str (), STDIN_FILENO, O_RDONLY))
1603                 exit(eDupStdinFailed);
1604 
1605         if (!args->m_stdout_path.empty ())
1606             if (!DupDescriptor(args->m_stdout_path.c_str (), STDOUT_FILENO, O_WRONLY | O_CREAT))
1607                 exit(eDupStdoutFailed);
1608 
1609         if (!args->m_stderr_path.empty ())
1610             if (!DupDescriptor(args->m_stderr_path.c_str (), STDERR_FILENO, O_WRONLY | O_CREAT))
1611                 exit(eDupStderrFailed);
1612 
1613         // Change working directory
1614         if (working_dir != NULL && working_dir[0])
1615           if (0 != ::chdir(working_dir))
1616               exit(eChdirFailed);
1617 
1618         // Disable ASLR if requested.
1619         if (args->m_launch_info.GetFlags ().Test (lldb::eLaunchFlagDisableASLR))
1620         {
1621             const int old_personality = personality (LLDB_PERSONALITY_GET_CURRENT_SETTINGS);
1622             if (old_personality == -1)
1623             {
1624                 // Can't retrieve Linux personality.  Cannot disable ASLR.
1625             }
1626             else
1627             {
1628                 const int new_personality = personality (ADDR_NO_RANDOMIZE | old_personality);
1629                 if (new_personality == -1)
1630                 {
1631                     // Disabling ASLR failed.
1632                 }
1633                 else
1634                 {
1635                     // Disabling ASLR succeeded.
1636                 }
1637             }
1638         }
1639 
1640         // Execute.  We should never return...
1641         execve(argv[0],
1642                const_cast<char *const *>(argv),
1643                const_cast<char *const *>(envp));
1644 
1645         // ...unless exec fails.  In which case we definitely need to end the child here.
1646         exit(eExecFailed);
1647     }
1648 
1649     //
1650     // This is the parent code here.
1651     //
1652     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1653 
1654     // Wait for the child process to trap on its call to execve.
1655     ::pid_t wpid;
1656     int status;
1657     if ((wpid = waitpid(pid, &status, 0)) < 0)
1658     {
1659         args->m_error.SetErrorToErrno();
1660 
1661         if (log)
1662             log->Printf ("NativeProcessLinux::%s waitpid for inferior failed with %s", __FUNCTION__, args->m_error.AsCString ());
1663 
1664         // Mark the inferior as invalid.
1665         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1666         monitor->SetState (StateType::eStateInvalid);
1667 
1668         return false;
1669     }
1670     else if (WIFEXITED(status))
1671     {
1672         // open, dup or execve likely failed for some reason.
1673         args->m_error.SetErrorToGenericError();
1674         switch (WEXITSTATUS(status))
1675         {
1676             case ePtraceFailed:
1677                 args->m_error.SetErrorString("Child ptrace failed.");
1678                 break;
1679             case eDupStdinFailed:
1680                 args->m_error.SetErrorString("Child open stdin failed.");
1681                 break;
1682             case eDupStdoutFailed:
1683                 args->m_error.SetErrorString("Child open stdout failed.");
1684                 break;
1685             case eDupStderrFailed:
1686                 args->m_error.SetErrorString("Child open stderr failed.");
1687                 break;
1688             case eChdirFailed:
1689                 args->m_error.SetErrorString("Child failed to set working directory.");
1690                 break;
1691             case eExecFailed:
1692                 args->m_error.SetErrorString("Child exec failed.");
1693                 break;
1694             case eSetGidFailed:
1695                 args->m_error.SetErrorString("Child setgid failed.");
1696                 break;
1697             default:
1698                 args->m_error.SetErrorString("Child returned unknown exit status.");
1699                 break;
1700         }
1701 
1702         if (log)
1703         {
1704             log->Printf ("NativeProcessLinux::%s inferior exited with status %d before issuing a STOP",
1705                     __FUNCTION__,
1706                     WEXITSTATUS(status));
1707         }
1708 
1709         // Mark the inferior as invalid.
1710         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1711         monitor->SetState (StateType::eStateInvalid);
1712 
1713         return false;
1714     }
1715     assert(WIFSTOPPED(status) && (wpid == static_cast< ::pid_t> (pid)) &&
1716            "Could not sync with inferior process.");
1717 
1718     if (log)
1719         log->Printf ("NativeProcessLinux::%s inferior started, now in stopped state", __FUNCTION__);
1720 
1721     if (!SetDefaultPtraceOpts(pid))
1722     {
1723         args->m_error.SetErrorToErrno();
1724         if (log)
1725             log->Printf ("NativeProcessLinux::%s inferior failed to set default ptrace options: %s",
1726                     __FUNCTION__,
1727                     args->m_error.AsCString ());
1728 
1729         // Mark the inferior as invalid.
1730         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1731         monitor->SetState (StateType::eStateInvalid);
1732 
1733         return false;
1734     }
1735 
1736     // Release the master terminal descriptor and pass it off to the
1737     // NativeProcessLinux instance.  Similarly stash the inferior pid.
1738     monitor->m_terminal_fd = terminal.ReleaseMasterFileDescriptor();
1739     monitor->m_pid = pid;
1740 
1741     // Set the terminal fd to be in non blocking mode (it simplifies the
1742     // implementation of ProcessLinux::GetSTDOUT to have a non-blocking
1743     // descriptor to read from).
1744     if (!EnsureFDFlags(monitor->m_terminal_fd, O_NONBLOCK, args->m_error))
1745     {
1746         if (log)
1747             log->Printf ("NativeProcessLinux::%s inferior EnsureFDFlags failed for ensuring terminal O_NONBLOCK setting: %s",
1748                     __FUNCTION__,
1749                     args->m_error.AsCString ());
1750 
1751         // Mark the inferior as invalid.
1752         // FIXME this could really use a new state - eStateLaunchFailure.  For now, using eStateInvalid.
1753         monitor->SetState (StateType::eStateInvalid);
1754 
1755         return false;
1756     }
1757 
1758     if (log)
1759         log->Printf ("NativeProcessLinux::%s() adding pid = %" PRIu64, __FUNCTION__, pid);
1760 
1761     thread_sp = monitor->AddThread (static_cast<lldb::tid_t> (pid));
1762     assert (thread_sp && "AddThread() returned a nullptr thread");
1763     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1764     monitor->SetCurrentThreadID (thread_sp->GetID ());
1765 
1766     // Let our process instance know the thread has stopped.
1767     monitor->SetState (StateType::eStateStopped);
1768 
1769     if (log)
1770     {
1771         if (args->m_error.Success ())
1772         {
1773             log->Printf ("NativeProcessLinux::%s inferior launching succeeded", __FUNCTION__);
1774         }
1775         else
1776         {
1777             log->Printf ("NativeProcessLinux::%s inferior launching failed: %s",
1778                 __FUNCTION__,
1779                 args->m_error.AsCString ());
1780         }
1781     }
1782     return args->m_error.Success();
1783 }
1784 
1785 void
1786 NativeProcessLinux::StartAttachOpThread(AttachArgs *args, lldb_private::Error &error)
1787 {
1788     static const char *g_thread_name = "lldb.process.linux.operation";
1789 
1790     if (m_operation_thread.IsJoinable())
1791         return;
1792 
1793     m_operation_thread = ThreadLauncher::LaunchThread(g_thread_name, AttachOpThread, args, &error);
1794 }
1795 
1796 void *
1797 NativeProcessLinux::AttachOpThread(void *arg)
1798 {
1799     AttachArgs *args = static_cast<AttachArgs*>(arg);
1800 
1801     if (!Attach(args)) {
1802         sem_post(&args->m_semaphore);
1803         return NULL;
1804     }
1805 
1806     ServeOperation(args);
1807     return NULL;
1808 }
1809 
1810 bool
1811 NativeProcessLinux::Attach(AttachArgs *args)
1812 {
1813     lldb::pid_t pid = args->m_pid;
1814 
1815     NativeProcessLinux *monitor = args->m_monitor;
1816     lldb::ThreadSP inferior;
1817     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
1818 
1819     // Use a map to keep track of the threads which we have attached/need to attach.
1820     Host::TidMap tids_to_attach;
1821     if (pid <= 1)
1822     {
1823         args->m_error.SetErrorToGenericError();
1824         args->m_error.SetErrorString("Attaching to process 1 is not allowed.");
1825         goto FINISH;
1826     }
1827 
1828     while (Host::FindProcessThreads(pid, tids_to_attach))
1829     {
1830         for (Host::TidMap::iterator it = tids_to_attach.begin();
1831              it != tids_to_attach.end();)
1832         {
1833             if (it->second == false)
1834             {
1835                 lldb::tid_t tid = it->first;
1836 
1837                 // Attach to the requested process.
1838                 // An attach will cause the thread to stop with a SIGSTOP.
1839                 if (PTRACE(PTRACE_ATTACH, tid, NULL, NULL, 0) < 0)
1840                 {
1841                     // No such thread. The thread may have exited.
1842                     // More error handling may be needed.
1843                     if (errno == ESRCH)
1844                     {
1845                         it = tids_to_attach.erase(it);
1846                         continue;
1847                     }
1848                     else
1849                     {
1850                         args->m_error.SetErrorToErrno();
1851                         goto FINISH;
1852                     }
1853                 }
1854 
1855                 int status;
1856                 // Need to use __WALL otherwise we receive an error with errno=ECHLD
1857                 // At this point we should have a thread stopped if waitpid succeeds.
1858                 if ((status = waitpid(tid, NULL, __WALL)) < 0)
1859                 {
1860                     // No such thread. The thread may have exited.
1861                     // More error handling may be needed.
1862                     if (errno == ESRCH)
1863                     {
1864                         it = tids_to_attach.erase(it);
1865                         continue;
1866                     }
1867                     else
1868                     {
1869                         args->m_error.SetErrorToErrno();
1870                         goto FINISH;
1871                     }
1872                 }
1873 
1874                 if (!SetDefaultPtraceOpts(tid))
1875                 {
1876                     args->m_error.SetErrorToErrno();
1877                     goto FINISH;
1878                 }
1879 
1880 
1881                 if (log)
1882                     log->Printf ("NativeProcessLinux::%s() adding tid = %" PRIu64, __FUNCTION__, tid);
1883 
1884                 it->second = true;
1885 
1886                 // Create the thread, mark it as stopped.
1887                 NativeThreadProtocolSP thread_sp (monitor->AddThread (static_cast<lldb::tid_t> (tid)));
1888                 assert (thread_sp && "AddThread() returned a nullptr");
1889                 reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGSTOP);
1890                 monitor->SetCurrentThreadID (thread_sp->GetID ());
1891             }
1892 
1893             // move the loop forward
1894             ++it;
1895         }
1896     }
1897 
1898     if (tids_to_attach.size() > 0)
1899     {
1900         monitor->m_pid = pid;
1901         // Let our process instance know the thread has stopped.
1902         monitor->SetState (StateType::eStateStopped);
1903     }
1904     else
1905     {
1906         args->m_error.SetErrorToGenericError();
1907         args->m_error.SetErrorString("No such process.");
1908     }
1909 
1910  FINISH:
1911     return args->m_error.Success();
1912 }
1913 
1914 bool
1915 NativeProcessLinux::SetDefaultPtraceOpts(lldb::pid_t pid)
1916 {
1917     long ptrace_opts = 0;
1918 
1919     // Have the child raise an event on exit.  This is used to keep the child in
1920     // limbo until it is destroyed.
1921     ptrace_opts |= PTRACE_O_TRACEEXIT;
1922 
1923     // Have the tracer trace threads which spawn in the inferior process.
1924     // TODO: if we want to support tracing the inferiors' child, add the
1925     // appropriate ptrace flags here (PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK)
1926     ptrace_opts |= PTRACE_O_TRACECLONE;
1927 
1928     // Have the tracer notify us before execve returns
1929     // (needed to disable legacy SIGTRAP generation)
1930     ptrace_opts |= PTRACE_O_TRACEEXEC;
1931 
1932     return PTRACE(PTRACE_SETOPTIONS, pid, NULL, (void*)ptrace_opts, 0) >= 0;
1933 }
1934 
1935 static ExitType convert_pid_status_to_exit_type (int status)
1936 {
1937     if (WIFEXITED (status))
1938         return ExitType::eExitTypeExit;
1939     else if (WIFSIGNALED (status))
1940         return ExitType::eExitTypeSignal;
1941     else if (WIFSTOPPED (status))
1942         return ExitType::eExitTypeStop;
1943     else
1944     {
1945         // We don't know what this is.
1946         return ExitType::eExitTypeInvalid;
1947     }
1948 }
1949 
1950 static int convert_pid_status_to_return_code (int status)
1951 {
1952     if (WIFEXITED (status))
1953         return WEXITSTATUS (status);
1954     else if (WIFSIGNALED (status))
1955         return WTERMSIG (status);
1956     else if (WIFSTOPPED (status))
1957         return WSTOPSIG (status);
1958     else
1959     {
1960         // We don't know what this is.
1961         return ExitType::eExitTypeInvalid;
1962     }
1963 }
1964 
1965 // Main process monitoring waitpid-loop handler.
1966 bool
1967 NativeProcessLinux::MonitorCallback(void *callback_baton,
1968                                 lldb::pid_t pid,
1969                                 bool exited,
1970                                 int signal,
1971                                 int status)
1972 {
1973     Log *log (GetLogIfAnyCategoriesSet (LIBLLDB_LOG_PROCESS));
1974 
1975     NativeProcessLinux *const process = static_cast<NativeProcessLinux*>(callback_baton);
1976     assert (process && "process is null");
1977     if (!process)
1978     {
1979         if (log)
1980             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " callback_baton was null, can't determine process to use", __FUNCTION__, pid);
1981         return true;
1982     }
1983 
1984     // Certain activities differ based on whether the pid is the tid of the main thread.
1985     const bool is_main_thread = (pid == process->GetID ());
1986 
1987     // Assume we keep monitoring by default.
1988     bool stop_monitoring = false;
1989 
1990     // Handle when the thread exits.
1991     if (exited)
1992     {
1993         if (log)
1994             log->Printf ("NativeProcessLinux::%s() got exit signal, tid = %"  PRIu64 " (%s main thread)", __FUNCTION__, pid, is_main_thread ? "is" : "is not");
1995 
1996         // This is a thread that exited.  Ensure we're not tracking it anymore.
1997         const bool thread_found = process->StopTrackingThread (pid);
1998 
1999         if (is_main_thread)
2000         {
2001             // We only set the exit status and notify the delegate if we haven't already set the process
2002             // state to an exited state.  We normally should have received a SIGTRAP | (PTRACE_EVENT_EXIT << 8)
2003             // for the main thread.
2004             const bool already_notified = (process->GetState() == StateType::eStateExited) | (process->GetState () == StateType::eStateCrashed);
2005             if (!already_notified)
2006             {
2007                 if (log)
2008                     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 ()));
2009                 // The main thread exited.  We're done monitoring.  Report to delegate.
2010                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
2011 
2012                 // Notify delegate that our process has exited.
2013                 process->SetState (StateType::eStateExited, true);
2014             }
2015             else
2016             {
2017                 if (log)
2018                     log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " main thread now exited (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
2019             }
2020             return true;
2021         }
2022         else
2023         {
2024             // Do we want to report to the delegate in this case?  I think not.  If this was an orderly
2025             // thread exit, we would already have received the SIGTRAP | (PTRACE_EVENT_EXIT << 8) signal,
2026             // and we would have done an all-stop then.
2027             if (log)
2028                 log->Printf ("NativeProcessLinux::%s() tid = %"  PRIu64 " handling non-main thread exit (%s)", __FUNCTION__, pid, thread_found ? "stopped tracking thread metadata" : "thread metadata not found");
2029 
2030             // Not the main thread, we keep going.
2031             return false;
2032         }
2033     }
2034 
2035     // Get details on the signal raised.
2036     siginfo_t info;
2037     int ptrace_err = 0;
2038 
2039     if (!process->GetSignalInfo (pid, &info, ptrace_err))
2040     {
2041         if (ptrace_err == EINVAL)
2042         {
2043             process->OnGroupStop (pid);
2044         }
2045         else
2046         {
2047             // ptrace(GETSIGINFO) failed (but not due to group-stop).
2048 
2049             // A return value of ESRCH means the thread/process is no longer on the system,
2050             // so it was killed somehow outside of our control.  Either way, we can't do anything
2051             // with it anymore.
2052 
2053             // We stop monitoring if it was the main thread.
2054             stop_monitoring = is_main_thread;
2055 
2056             // Stop tracking the metadata for the thread since it's entirely off the system now.
2057             const bool thread_found = process->StopTrackingThread (pid);
2058 
2059             if (log)
2060                 log->Printf ("NativeProcessLinux::%s GetSignalInfo failed: %s, tid = %" PRIu64 ", signal = %d, status = %d (%s, %s, %s)",
2061                              __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");
2062 
2063             if (is_main_thread)
2064             {
2065                 // Notify the delegate - our process is not available but appears to have been killed outside
2066                 // our control.  Is eStateExited the right exit state in this case?
2067                 process->SetExitStatus (convert_pid_status_to_exit_type (status), convert_pid_status_to_return_code (status), nullptr, true);
2068                 process->SetState (StateType::eStateExited, true);
2069             }
2070             else
2071             {
2072                 // This thread was pulled out from underneath us.  Anything to do here? Do we want to do an all stop?
2073                 if (log)
2074                     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);
2075             }
2076         }
2077     }
2078     else
2079     {
2080         // We have retrieved the signal info.  Dispatch appropriately.
2081         if (info.si_signo == SIGTRAP)
2082             process->MonitorSIGTRAP(&info, pid);
2083         else
2084             process->MonitorSignal(&info, pid, exited);
2085 
2086         stop_monitoring = false;
2087     }
2088 
2089     return stop_monitoring;
2090 }
2091 
2092 void
2093 NativeProcessLinux::MonitorSIGTRAP(const siginfo_t *info, lldb::pid_t pid)
2094 {
2095     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2096     const bool is_main_thread = (pid == GetID ());
2097 
2098     assert(info && info->si_signo == SIGTRAP && "Unexpected child signal!");
2099     if (!info)
2100         return;
2101 
2102     // See if we can find a thread for this signal.
2103     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2104     if (!thread_sp)
2105     {
2106         if (log)
2107             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2108     }
2109 
2110     switch (info->si_code)
2111     {
2112     // TODO: these two cases are required if we want to support tracing of the inferiors' children.  We'd need this to debug a monitor.
2113     // case (SIGTRAP | (PTRACE_EVENT_FORK << 8)):
2114     // case (SIGTRAP | (PTRACE_EVENT_VFORK << 8)):
2115 
2116     case (SIGTRAP | (PTRACE_EVENT_CLONE << 8)):
2117     {
2118         lldb::tid_t tid = LLDB_INVALID_THREAD_ID;
2119 
2120         unsigned long event_message = 0;
2121         if (GetEventMessage(pid, &event_message))
2122             tid = static_cast<lldb::tid_t> (event_message);
2123 
2124         if (log)
2125             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " received thread creation event for tid %" PRIu64, __FUNCTION__, pid, tid);
2126 
2127         // If we don't track the thread yet: create it, mark as stopped.
2128         // If we do track it, this is the wait we needed.  Now resume the new thread.
2129         // In all cases, resume the current (i.e. main process) thread.
2130         bool created_now = false;
2131         thread_sp = GetOrCreateThread (tid, created_now);
2132         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2133 
2134         // If the thread was already tracked, it means the created thread already received its SI_USER notification of creation.
2135         if (!created_now)
2136         {
2137             // FIXME loops like we want to stop all theads here.
2138             // StopAllThreads
2139 
2140             // We can now resume the newly created thread since it is fully created.
2141             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2142             Resume (tid, LLDB_INVALID_SIGNAL_NUMBER);
2143         }
2144         else
2145         {
2146             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2147             // this thread is ready to go.
2148             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2149         }
2150 
2151         // In all cases, we can resume the main thread here.
2152         Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2153         break;
2154     }
2155 
2156     case (SIGTRAP | (PTRACE_EVENT_EXEC << 8)):
2157     {
2158         NativeThreadProtocolSP main_thread_sp;
2159 
2160         if (log)
2161             log->Printf ("NativeProcessLinux::%s() received exec event, code = %d", __FUNCTION__, info->si_code ^ SIGTRAP);
2162 
2163         // Remove all but the main thread here.
2164         // FIXME check if we really need to do this - how does ptrace behave under exec when multiple threads were present
2165         // before the exec?  If we get all the detach signals right, we don't need to do this.  However, it makes it clearer
2166         // what we should really be tracking.
2167         {
2168             Mutex::Locker locker (m_threads_mutex);
2169 
2170             if (log)
2171                 log->Printf ("NativeProcessLinux::%s exec received, stop tracking all but main thread", __FUNCTION__);
2172 
2173             for (auto thread_sp : m_threads)
2174             {
2175                 const bool is_main_thread = thread_sp && thread_sp->GetID () == GetID ();
2176                 if (is_main_thread)
2177                 {
2178                     main_thread_sp = thread_sp;
2179                     if (log)
2180                         log->Printf ("NativeProcessLinux::%s found main thread with tid %" PRIu64 ", keeping", __FUNCTION__, main_thread_sp->GetID ());
2181                 }
2182                 else
2183                 {
2184                     if (log)
2185                         log->Printf ("NativeProcessLinux::%s discarding non-main-thread tid %" PRIu64 " due to exec", __FUNCTION__, thread_sp->GetID ());
2186                 }
2187             }
2188 
2189             m_threads.clear ();
2190 
2191             if (main_thread_sp)
2192             {
2193                 m_threads.push_back (main_thread_sp);
2194                 SetCurrentThreadID (main_thread_sp->GetID ());
2195                 reinterpret_cast<NativeThreadLinux*>(main_thread_sp.get())->SetStoppedByExec ();
2196             }
2197             else
2198             {
2199                 SetCurrentThreadID (LLDB_INVALID_THREAD_ID);
2200                 if (log)
2201                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 "no main thread found, discarded all threads, we're in a no-thread state!", __FUNCTION__, GetID ());
2202             }
2203         }
2204 
2205         // Let our delegate know we have just exec'd.
2206         NotifyDidExec ();
2207 
2208         // If we have a main thread, indicate we are stopped.
2209         assert (main_thread_sp && "exec called during ptraced process but no main thread metadata tracked");
2210         SetState (StateType::eStateStopped);
2211 
2212         break;
2213     }
2214 
2215     case (SIGTRAP | (PTRACE_EVENT_EXIT << 8)):
2216     {
2217         // The inferior process or one of its threads is about to exit.
2218         unsigned long data = 0;
2219         if (!GetEventMessage(pid, &data))
2220             data = -1;
2221 
2222         if (log)
2223         {
2224             log->Printf ("NativeProcessLinux::%s() received PTRACE_EVENT_EXIT, data = %lx (WIFEXITED=%s,WIFSIGNALED=%s), pid = %" PRIu64 " (%s)",
2225                          __FUNCTION__,
2226                          data, WIFEXITED (data) ? "true" : "false", WIFSIGNALED (data) ? "true" : "false",
2227                          pid,
2228                     is_main_thread ? "is main thread" : "not main thread");
2229         }
2230 
2231         // Set the thread to exited.
2232         if (thread_sp)
2233             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetExited ();
2234         else
2235         {
2236             if (log)
2237                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " failed to retrieve thread for tid %" PRIu64", cannot set thread state", __FUNCTION__, GetID (), pid);
2238         }
2239 
2240         if (is_main_thread)
2241         {
2242             SetExitStatus (convert_pid_status_to_exit_type (data), convert_pid_status_to_return_code (data), nullptr, true);
2243         }
2244 
2245         // Resume the thread so it completely exits.
2246         Resume (pid, LLDB_INVALID_SIGNAL_NUMBER);
2247 
2248         break;
2249     }
2250 
2251     case 0:
2252     case TRAP_TRACE:
2253         // We receive this on single stepping.
2254         if (log)
2255             log->Printf ("NativeProcessLinux::%s() received trace event, pid = %" PRIu64 " (single stepping)", __FUNCTION__, pid);
2256 
2257         if (thread_sp)
2258         {
2259             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2260             SetCurrentThreadID (thread_sp->GetID ());
2261         }
2262         else
2263         {
2264             if (log)
2265                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 " single stepping received trace but thread not found", __FUNCTION__, GetID (), pid);
2266         }
2267 
2268         // Tell the process we have a stop (from single stepping).
2269         SetState (StateType::eStateStopped, true);
2270         break;
2271 
2272     case SI_KERNEL:
2273     case TRAP_BRKPT:
2274         if (log)
2275             log->Printf ("NativeProcessLinux::%s() received breakpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2276 
2277         // Mark the thread as stopped at breakpoint.
2278         if (thread_sp)
2279         {
2280             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2281             Error error = FixupBreakpointPCAsNeeded (thread_sp);
2282             if (error.Fail ())
2283             {
2284                 if (log)
2285                     log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " fixup: %s", __FUNCTION__, pid, error.AsCString ());
2286             }
2287         }
2288         else
2289         {
2290             if (log)
2291                 log->Printf ("NativeProcessLinux::%s()  pid = %" PRIu64 ": warning, cannot process software breakpoint since no thread metadata", __FUNCTION__, pid);
2292         }
2293 
2294 
2295         // Tell the process we have a stop from this thread.
2296         SetCurrentThreadID (pid);
2297         SetState (StateType::eStateStopped, true);
2298         break;
2299 
2300     case TRAP_HWBKPT:
2301         if (log)
2302             log->Printf ("NativeProcessLinux::%s() received watchpoint event, pid = %" PRIu64, __FUNCTION__, pid);
2303 
2304         // Mark the thread as stopped at watchpoint.
2305         // The address is at (lldb::addr_t)info->si_addr if we need it.
2306         if (thread_sp)
2307             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (SIGTRAP);
2308         else
2309         {
2310             if (log)
2311                 log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ": warning, cannot process hardware breakpoint since no thread metadata", __FUNCTION__, GetID (), pid);
2312         }
2313 
2314         // Tell the process we have a stop from this thread.
2315         SetCurrentThreadID (pid);
2316         SetState (StateType::eStateStopped, true);
2317         break;
2318 
2319     case SIGTRAP:
2320     case (SIGTRAP | 0x80):
2321         if (log)
2322             log->Printf ("NativeProcessLinux::%s() received system call stop event, pid %" PRIu64 "tid %" PRIu64, __FUNCTION__, GetID (), pid);
2323         // Ignore these signals until we know more about them.
2324         Resume(pid, 0);
2325         break;
2326 
2327     default:
2328         assert(false && "Unexpected SIGTRAP code!");
2329         if (log)
2330             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)));
2331         break;
2332 
2333     }
2334 }
2335 
2336 void
2337 NativeProcessLinux::MonitorSignal(const siginfo_t *info, lldb::pid_t pid, bool exited)
2338 {
2339     assert (info && "null info");
2340     if (!info)
2341         return;
2342 
2343     const int signo = info->si_signo;
2344     const bool is_from_llgs = info->si_pid == getpid ();
2345 
2346     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2347 
2348     // POSIX says that process behaviour is undefined after it ignores a SIGFPE,
2349     // SIGILL, SIGSEGV, or SIGBUS *unless* that signal was generated by a
2350     // kill(2) or raise(3).  Similarly for tgkill(2) on Linux.
2351     //
2352     // IOW, user generated signals never generate what we consider to be a
2353     // "crash".
2354     //
2355     // Similarly, ACK signals generated by this monitor.
2356 
2357     // See if we can find a thread for this signal.
2358     NativeThreadProtocolSP thread_sp = GetThreadByID (pid);
2359     if (!thread_sp)
2360     {
2361         if (log)
2362             log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " no thread found for tid %" PRIu64, __FUNCTION__, GetID (), pid);
2363     }
2364 
2365     // Handle the signal.
2366     if (info->si_code == SI_TKILL || info->si_code == SI_USER)
2367     {
2368         if (log)
2369             log->Printf ("NativeProcessLinux::%s() received signal %s (%d) with code %s, (siginfo pid = %d (%s), waitpid pid = %" PRIu64 ")",
2370                             __FUNCTION__,
2371                             GetUnixSignals ().GetSignalAsCString (signo),
2372                             signo,
2373                             (info->si_code == SI_TKILL ? "SI_TKILL" : "SI_USER"),
2374                             info->si_pid,
2375                             is_from_llgs ? "from llgs" : "not from llgs",
2376                             pid);
2377     }
2378 
2379     // Check for new thread notification.
2380     if ((info->si_pid == 0) && (info->si_code == SI_USER))
2381     {
2382         // A new thread creation is being signaled.  This is one of two parts that come in
2383         // a non-deterministic order.  pid is the thread id.
2384         if (log)
2385             log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": new thread notification",
2386                      __FUNCTION__, GetID (), pid);
2387 
2388         // Did we already create the thread?
2389         bool created_now = false;
2390         thread_sp = GetOrCreateThread (pid, created_now);
2391         assert (thread_sp.get() && "failed to get or create the tracking data for newly created inferior thread");
2392 
2393         // If the thread was already tracked, it means the main thread already received its SIGTRAP for the create.
2394         if (!created_now)
2395         {
2396             // We can now resume this thread up since it is fully created.
2397             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetRunning ();
2398             Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2399         }
2400         else
2401         {
2402             // Mark the thread as currently launching.  Need to wait for SIGTRAP clone on the main thread before
2403             // this thread is ready to go.
2404             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetLaunching ();
2405         }
2406 
2407         // Done handling.
2408         return;
2409     }
2410 
2411     // Check for thread stop notification.
2412     if (is_from_llgs && (info->si_code == SI_TKILL) && (signo == SIGSTOP))
2413     {
2414         // This is a tgkill()-based stop.
2415         if (thread_sp)
2416         {
2417             // An inferior thread just stopped.  Mark it as such.
2418             reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2419             SetCurrentThreadID (thread_sp->GetID ());
2420 
2421             // Remove this tid from the wait-for-stop set.
2422             Mutex::Locker locker (m_wait_for_stop_tids_mutex);
2423 
2424             auto removed_count = m_wait_for_stop_tids.erase (thread_sp->GetID ());
2425             if (removed_count < 1)
2426             {
2427                 log->Printf ("NativeProcessLinux::%s() pid = %" PRIu64 " tid %" PRIu64 ": tgkill()-stopped thread not in m_wait_for_stop_tids",
2428                              __FUNCTION__, GetID (), thread_sp->GetID ());
2429 
2430             }
2431 
2432             // If this is the last thread in the m_wait_for_stop_tids, we need to notify
2433             // the delegate that a stop has occurred now that every thread that was supposed
2434             // to stop has stopped.
2435             if (m_wait_for_stop_tids.empty ())
2436             {
2437                 if (log)
2438                 {
2439                     log->Printf ("NativeProcessLinux::%s() pid %" PRIu64 " tid %" PRIu64 ", setting process state to stopped now that all tids marked for stop have completed",
2440                                  __FUNCTION__,
2441                                  GetID (),
2442                                  pid);
2443                 }
2444                 SetState (StateType::eStateStopped, true);
2445             }
2446         }
2447 
2448         // Done handling.
2449         return;
2450     }
2451 
2452     if (log)
2453         log->Printf ("NativeProcessLinux::%s() received signal %s", __FUNCTION__, GetUnixSignals ().GetSignalAsCString (signo));
2454 
2455     switch (signo)
2456     {
2457     case SIGSEGV:
2458         {
2459             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2460 
2461             // FIXME figure out how to propagate this properly.  Seems like it
2462             // should go in ThreadStopInfo.
2463             // We can get more details on the exact nature of the crash here.
2464             // ProcessMessage::CrashReason reason = GetCrashReasonForSIGSEGV(info);
2465             if (!exited)
2466             {
2467                 // This is just a pre-signal-delivery notification of the incoming signal.
2468                 // Send a stop to the debugger.
2469                 if (thread_sp)
2470                 {
2471                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2472                     SetCurrentThreadID (thread_sp->GetID ());
2473                 }
2474                 SetState (StateType::eStateStopped, true);
2475             }
2476             else
2477             {
2478                 if (thread_sp)
2479                 {
2480                     // FIXME figure out what type this is.
2481                     const uint64_t exception_type = static_cast<uint64_t> (SIGSEGV);
2482                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2483                 }
2484                 SetState (StateType::eStateCrashed, true);
2485             }
2486         }
2487         break;
2488 
2489     case SIGABRT:
2490     case SIGILL:
2491     case SIGFPE:
2492     case SIGBUS:
2493         {
2494             // Break these out into separate cases once I have more data for each type of signal.
2495             lldb::addr_t fault_addr = reinterpret_cast<lldb::addr_t>(info->si_addr);
2496             if (!exited)
2497             {
2498                 // This is just a pre-signal-delivery notification of the incoming signal.
2499                 // Send a stop to the debugger.
2500                 if (thread_sp)
2501                 {
2502                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetStoppedBySignal (signo);
2503                     SetCurrentThreadID (thread_sp->GetID ());
2504                 }
2505                 SetState (StateType::eStateStopped, true);
2506             }
2507             else
2508             {
2509                 if (thread_sp)
2510                 {
2511                     // FIXME figure out how to report exit by signal correctly.
2512                     const uint64_t exception_type = static_cast<uint64_t> (SIGABRT);
2513                     reinterpret_cast<NativeThreadLinux*> (thread_sp.get ())->SetCrashedWithException (exception_type, fault_addr);
2514                 }
2515                 SetState (StateType::eStateCrashed, true);
2516             }
2517         }
2518         break;
2519 
2520     case SIGSTOP:
2521         {
2522             if (log)
2523             {
2524                 if (is_from_llgs)
2525                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " received SIGSTOP from llgs, most likely an interrupt", __FUNCTION__, GetID (), pid);
2526                 else
2527                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " received SIGSTOP from outside of debugger", __FUNCTION__, GetID (), pid);
2528             }
2529 
2530             // Save group stop tids to wait for.
2531             SetGroupStopTids (pid, SIGSTOP);
2532             // Fall through to deliver signal to thread.
2533             // This will trigger a group stop sequence, after which we'll notify the process that everything stopped.
2534         }
2535 
2536     default:
2537         {
2538             if (log)
2539                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " resuming thread with signal %s (%d)", __FUNCTION__, GetID (), pid, GetUnixSignals().GetSignalAsCString (signo), signo);
2540 
2541             // Pass the signal on to the inferior.
2542             const bool resume_success = Resume (pid, signo);
2543 
2544             if (log)
2545                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " resume %s", __FUNCTION__, GetID (), pid, resume_success ? "SUCCESS" : "FAILURE");
2546 
2547         }
2548         break;
2549     }
2550 }
2551 
2552 void
2553 NativeProcessLinux::SetGroupStopTids (lldb::tid_t signaled_thread_tid, int signo)
2554 {
2555     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
2556 
2557     // Lock 1 - thread lock.
2558     {
2559         Mutex::Locker locker (m_threads_mutex);
2560         // Lock 2 - group stop tids
2561         {
2562             Mutex::Locker locker (m_wait_for_group_stop_tids_mutex);
2563             if (log)
2564                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " loading up known threads in set%s",
2565                              __FUNCTION__,
2566                              GetID (),
2567                              signaled_thread_tid,
2568                              m_wait_for_group_stop_tids.empty () ? " (currently empty)"
2569                                 : "(group_stop_tids not empty?!?)");
2570 
2571             // Add all known threads not already stopped into the wait for group-stop tids.
2572             for (auto thread_sp : m_threads)
2573             {
2574                 int unused_signo = LLDB_INVALID_SIGNAL_NUMBER;
2575                 if (thread_sp && !((NativeThreadLinux*)thread_sp.get())->IsStopped (&unused_signo))
2576                 {
2577                     // Wait on this thread for a group stop before we notify the delegate about the process state change.
2578                     m_wait_for_group_stop_tids.insert (thread_sp->GetID ());
2579                 }
2580             }
2581 
2582             m_group_stop_signal_tid = signaled_thread_tid;
2583             m_group_stop_signal = signo;
2584         }
2585     }
2586 }
2587 
2588 void
2589 NativeProcessLinux::OnGroupStop (lldb::tid_t tid)
2590 {
2591     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
2592     bool should_tell_delegate = false;
2593 
2594     // Lock 1 - thread lock.
2595     {
2596         Mutex::Locker locker (m_threads_mutex);
2597         // Lock 2 - group stop tids
2598         {
2599             Mutex::Locker locker (m_wait_for_group_stop_tids_mutex);
2600 
2601             // Remove this thread from the set.
2602             auto remove_result = m_wait_for_group_stop_tids.erase (tid);
2603             if (log)
2604                 log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " tried to remove tid from group-stop set: %s",
2605                              __FUNCTION__,
2606                              GetID (),
2607                              tid,
2608                              remove_result > 0 ? "SUCCESS" : "FAILURE");
2609 
2610             // Grab the thread metadata for this thread.
2611             NativeThreadProtocolSP thread_sp = GetThreadByIDUnlocked (tid);
2612             if (thread_sp)
2613             {
2614                 NativeThreadLinux *const linux_thread = static_cast<NativeThreadLinux*> (thread_sp.get ());
2615                 if (thread_sp->GetID () == m_group_stop_signal_tid)
2616                 {
2617                     linux_thread->SetStoppedBySignal (m_group_stop_signal);
2618                     if (log)
2619                         log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " set group stop tid to state 'stopped by signal %d'",
2620                                      __FUNCTION__,
2621                                      GetID (),
2622                                      tid,
2623                                      m_group_stop_signal);
2624                 }
2625                 else
2626                 {
2627                     int stopping_signal = LLDB_INVALID_SIGNAL_NUMBER;
2628                     if (linux_thread->IsStopped (&stopping_signal))
2629                     {
2630                         if (log)
2631                             log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " thread is already stopped with signal %d, not clearing",
2632                                          __FUNCTION__,
2633                                          GetID (),
2634                                          tid,
2635                                          stopping_signal);
2636 
2637                     }
2638                     else
2639                     {
2640                         linux_thread->SetStoppedBySignal (0);
2641                         if (log)
2642                             log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " set stopped by signal with signal 0 (i.e. debugger-initiated stop)",
2643                                          __FUNCTION__,
2644                                          GetID (),
2645                                          tid);
2646 
2647                     }
2648                 }
2649             }
2650             else
2651             {
2652                 if (log)
2653                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " WARNING failed to find thread metadata for tid",
2654                                  __FUNCTION__,
2655                                  GetID (),
2656                                  tid);
2657 
2658             }
2659 
2660             // If there are no more threads we're waiting on for group stop, signal the process.
2661             if (m_wait_for_group_stop_tids.empty ())
2662             {
2663                 if (log)
2664                     log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " done waiting for group stop, will notify delegate of process state change",
2665                                  __FUNCTION__,
2666                                  GetID (),
2667                                  tid);
2668 
2669                 SetCurrentThreadID (m_group_stop_signal_tid);
2670 
2671                 // Tell the delegate about the stop event, after we release our mutexes.
2672                 should_tell_delegate = true;
2673             }
2674         }
2675     }
2676 
2677     // If we're ready to broadcast the process event change, do it now that we're no longer
2678     // holding any locks.  Note this does introduce a potential race, we should think about
2679     // adding a notification queue.
2680     if (should_tell_delegate)
2681     {
2682         if (log)
2683             log->Printf ("NativeProcessLinux::%s pid = %" PRIu64 " tid %" PRIu64 " done waiting for group stop, notifying delegate of process state change",
2684                          __FUNCTION__,
2685                          GetID (),
2686                          tid);
2687         SetState (StateType::eStateStopped, true);
2688     }
2689 }
2690 
2691 Error
2692 NativeProcessLinux::Resume (const ResumeActionList &resume_actions)
2693 {
2694     Error error;
2695 
2696     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_THREAD));
2697     if (log)
2698         log->Printf ("NativeProcessLinux::%s called: pid %" PRIu64, __FUNCTION__, GetID ());
2699 
2700     int run_thread_count = 0;
2701     int stop_thread_count = 0;
2702     int step_thread_count = 0;
2703 
2704     std::vector<NativeThreadProtocolSP> new_stop_threads;
2705 
2706     Mutex::Locker locker (m_threads_mutex);
2707     for (auto thread_sp : m_threads)
2708     {
2709         assert (thread_sp && "thread list should not contain NULL threads");
2710         NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get ());
2711 
2712         const ResumeAction *const action = resume_actions.GetActionForThread (thread_sp->GetID (), true);
2713         assert (action && "NULL ResumeAction returned for thread during Resume ()");
2714 
2715         if (log)
2716         {
2717             log->Printf ("NativeProcessLinux::%s processing resume action state %s for pid %" PRIu64 " tid %" PRIu64,
2718                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2719         }
2720 
2721         switch (action->state)
2722         {
2723         case eStateRunning:
2724             // Run the thread, possibly feeding it the signal.
2725             linux_thread_p->SetRunning ();
2726             if (action->signal > 0)
2727             {
2728                 // Resume the thread and deliver the given signal,
2729                 // then mark as delivered.
2730                 Resume (thread_sp->GetID (), action->signal);
2731                 resume_actions.SetSignalHandledForThread (thread_sp->GetID ());
2732             }
2733             else
2734             {
2735                 // Just resume the thread with no signal.
2736                 Resume (thread_sp->GetID (), LLDB_INVALID_SIGNAL_NUMBER);
2737             }
2738             ++run_thread_count;
2739             break;
2740 
2741         case eStateStepping:
2742             // Note: if we have multiple threads, we may need to stop
2743             // the other threads first, then step this one.
2744             linux_thread_p->SetStepping ();
2745             if (SingleStep (thread_sp->GetID (), 0))
2746             {
2747                 if (log)
2748                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step succeeded",
2749                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2750             }
2751             else
2752             {
2753                 if (log)
2754                     log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 " single step failed",
2755                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2756             }
2757             ++step_thread_count;
2758             break;
2759 
2760         case eStateSuspended:
2761         case eStateStopped:
2762             if (!StateIsStoppedState (linux_thread_p->GetState (), false))
2763                 new_stop_threads.push_back (thread_sp);
2764             else
2765             {
2766                 if (log)
2767                     log->Printf ("NativeProcessLinux::%s no need to stop pid %" PRIu64 " tid %" PRIu64 ", thread state already %s",
2768                                  __FUNCTION__, GetID (), thread_sp->GetID (), StateAsCString (linux_thread_p->GetState ()));
2769             }
2770 
2771             ++stop_thread_count;
2772             break;
2773 
2774         default:
2775             return Error ("NativeProcessLinux::%s (): unexpected state %s specified for pid %" PRIu64 ", tid %" PRIu64,
2776                     __FUNCTION__, StateAsCString (action->state), GetID (), thread_sp->GetID ());
2777         }
2778     }
2779 
2780     // If any thread was set to run, notify the process state as running.
2781     if (run_thread_count > 0)
2782         SetState (StateType::eStateRunning, true);
2783 
2784     // Now do a tgkill SIGSTOP on each thread we want to stop.
2785     if (!new_stop_threads.empty ())
2786     {
2787         // Lock the m_wait_for_stop_tids set so we can fill it with every thread we expect to have stopped.
2788         Mutex::Locker stop_thread_id_locker (m_wait_for_stop_tids_mutex);
2789         for (auto thread_sp : new_stop_threads)
2790         {
2791             // Send a stop signal to the thread.
2792             const int result = tgkill (GetID (), thread_sp->GetID (), SIGSTOP);
2793             if (result != 0)
2794             {
2795                 // tgkill failed.
2796                 if (log)
2797                     log->Printf ("NativeProcessLinux::%s error: tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 "failed, retval %d",
2798                                  __FUNCTION__, GetID (), thread_sp->GetID (), result);
2799             }
2800             else
2801             {
2802                 // tgkill succeeded.  Don't mark the thread state, though.  Let the signal
2803                 // handling mark it.
2804                 if (log)
2805                     log->Printf ("NativeProcessLinux::%s tgkill SIGSTOP for pid %" PRIu64 " tid %" PRIu64 " succeeded",
2806                                  __FUNCTION__, GetID (), thread_sp->GetID ());
2807 
2808                 // Add it to the set of threads we expect to signal a stop.
2809                 // We won't tell the delegate about it until this list drains to empty.
2810                 m_wait_for_stop_tids.insert (thread_sp->GetID ());
2811             }
2812         }
2813     }
2814 
2815     return error;
2816 }
2817 
2818 Error
2819 NativeProcessLinux::Halt ()
2820 {
2821     Error error;
2822 
2823     // FIXME check if we're already stopped
2824     const bool is_stopped = false;
2825     if (is_stopped)
2826         return error;
2827 
2828     if (kill (GetID (), SIGSTOP) != 0)
2829         error.SetErrorToErrno ();
2830 
2831     return error;
2832 }
2833 
2834 Error
2835 NativeProcessLinux::Detach ()
2836 {
2837     Error error;
2838 
2839     // Tell ptrace to detach from the process.
2840     if (GetID () != LLDB_INVALID_PROCESS_ID)
2841         error = Detach (GetID ());
2842 
2843     // Stop monitoring the inferior.
2844     StopMonitor ();
2845 
2846     // No error.
2847     return error;
2848 }
2849 
2850 Error
2851 NativeProcessLinux::Signal (int signo)
2852 {
2853     Error error;
2854 
2855     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2856     if (log)
2857         log->Printf ("NativeProcessLinux::%s: sending signal %d (%s) to pid %" PRIu64,
2858                 __FUNCTION__, signo,  GetUnixSignals ().GetSignalAsCString (signo), GetID ());
2859 
2860     if (kill(GetID(), signo))
2861         error.SetErrorToErrno();
2862 
2863     return error;
2864 }
2865 
2866 Error
2867 NativeProcessLinux::Kill ()
2868 {
2869     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2870     if (log)
2871         log->Printf ("NativeProcessLinux::%s called for PID %" PRIu64, __FUNCTION__, GetID ());
2872 
2873     Error error;
2874 
2875     switch (m_state)
2876     {
2877         case StateType::eStateInvalid:
2878         case StateType::eStateExited:
2879         case StateType::eStateCrashed:
2880         case StateType::eStateDetached:
2881         case StateType::eStateUnloaded:
2882             // Nothing to do - the process is already dead.
2883             if (log)
2884                 log->Printf ("NativeProcessLinux::%s ignored for PID %" PRIu64 " due to current state: %s", __FUNCTION__, GetID (), StateAsCString (m_state));
2885             return error;
2886 
2887         case StateType::eStateConnected:
2888         case StateType::eStateAttaching:
2889         case StateType::eStateLaunching:
2890         case StateType::eStateStopped:
2891         case StateType::eStateRunning:
2892         case StateType::eStateStepping:
2893         case StateType::eStateSuspended:
2894             // We can try to kill a process in these states.
2895             break;
2896     }
2897 
2898     if (kill (GetID (), SIGKILL) != 0)
2899     {
2900         error.SetErrorToErrno ();
2901         return error;
2902     }
2903 
2904     return error;
2905 }
2906 
2907 static Error
2908 ParseMemoryRegionInfoFromProcMapsLine (const std::string &maps_line, MemoryRegionInfo &memory_region_info)
2909 {
2910     memory_region_info.Clear();
2911 
2912     StringExtractor line_extractor (maps_line.c_str ());
2913 
2914     // Format: {address_start_hex}-{address_end_hex} perms offset  dev   inode   pathname
2915     // perms: rwxp   (letter is present if set, '-' if not, final character is p=private, s=shared).
2916 
2917     // Parse out the starting address
2918     lldb::addr_t start_address = line_extractor.GetHexMaxU64 (false, 0);
2919 
2920     // Parse out hyphen separating start and end address from range.
2921     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != '-'))
2922         return Error ("malformed /proc/{pid}/maps entry, missing dash between address range");
2923 
2924     // Parse out the ending address
2925     lldb::addr_t end_address = line_extractor.GetHexMaxU64 (false, start_address);
2926 
2927     // Parse out the space after the address.
2928     if (!line_extractor.GetBytesLeft () || (line_extractor.GetChar () != ' '))
2929         return Error ("malformed /proc/{pid}/maps entry, missing space after range");
2930 
2931     // Save the range.
2932     memory_region_info.GetRange ().SetRangeBase (start_address);
2933     memory_region_info.GetRange ().SetRangeEnd (end_address);
2934 
2935     // Parse out each permission entry.
2936     if (line_extractor.GetBytesLeft () < 4)
2937         return Error ("malformed /proc/{pid}/maps entry, missing some portion of permissions");
2938 
2939     // Handle read permission.
2940     const char read_perm_char = line_extractor.GetChar ();
2941     if (read_perm_char == 'r')
2942         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eYes);
2943     else
2944     {
2945         assert ( (read_perm_char == '-') && "unexpected /proc/{pid}/maps read permission char" );
2946         memory_region_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
2947     }
2948 
2949     // Handle write permission.
2950     const char write_perm_char = line_extractor.GetChar ();
2951     if (write_perm_char == 'w')
2952         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eYes);
2953     else
2954     {
2955         assert ( (write_perm_char == '-') && "unexpected /proc/{pid}/maps write permission char" );
2956         memory_region_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
2957     }
2958 
2959     // Handle execute permission.
2960     const char exec_perm_char = line_extractor.GetChar ();
2961     if (exec_perm_char == 'x')
2962         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eYes);
2963     else
2964     {
2965         assert ( (exec_perm_char == '-') && "unexpected /proc/{pid}/maps exec permission char" );
2966         memory_region_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
2967     }
2968 
2969     return Error ();
2970 }
2971 
2972 Error
2973 NativeProcessLinux::GetMemoryRegionInfo (lldb::addr_t load_addr, MemoryRegionInfo &range_info)
2974 {
2975     // FIXME review that the final memory region returned extends to the end of the virtual address space,
2976     // with no perms if it is not mapped.
2977 
2978     // Use an approach that reads memory regions from /proc/{pid}/maps.
2979     // Assume proc maps entries are in ascending order.
2980     // FIXME assert if we find differently.
2981     Mutex::Locker locker (m_mem_region_cache_mutex);
2982 
2983     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
2984     Error error;
2985 
2986     if (m_supports_mem_region == LazyBool::eLazyBoolNo)
2987     {
2988         // We're done.
2989         error.SetErrorString ("unsupported");
2990         return error;
2991     }
2992 
2993     // If our cache is empty, pull the latest.  There should always be at least one memory region
2994     // if memory region handling is supported.
2995     if (m_mem_region_cache.empty ())
2996     {
2997         error = ProcFileReader::ProcessLineByLine (GetID (), "maps",
2998              [&] (const std::string &line) -> bool
2999              {
3000                  MemoryRegionInfo info;
3001                  const Error parse_error = ParseMemoryRegionInfoFromProcMapsLine (line, info);
3002                  if (parse_error.Success ())
3003                  {
3004                      m_mem_region_cache.push_back (info);
3005                      return true;
3006                  }
3007                  else
3008                  {
3009                      if (log)
3010                          log->Printf ("NativeProcessLinux::%s failed to parse proc maps line '%s': %s", __FUNCTION__, line.c_str (), error.AsCString ());
3011                      return false;
3012                  }
3013              });
3014 
3015         // If we had an error, we'll mark unsupported.
3016         if (error.Fail ())
3017         {
3018             m_supports_mem_region = LazyBool::eLazyBoolNo;
3019             return error;
3020         }
3021         else if (m_mem_region_cache.empty ())
3022         {
3023             // No entries after attempting to read them.  This shouldn't happen if /proc/{pid}/maps
3024             // is supported.  Assume we don't support map entries via procfs.
3025             if (log)
3026                 log->Printf ("NativeProcessLinux::%s failed to find any procfs maps entries, assuming no support for memory region metadata retrieval", __FUNCTION__);
3027             m_supports_mem_region = LazyBool::eLazyBoolNo;
3028             error.SetErrorString ("not supported");
3029             return error;
3030         }
3031 
3032         if (log)
3033             log->Printf ("NativeProcessLinux::%s read %" PRIu64 " memory region entries from /proc/%" PRIu64 "/maps", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()), GetID ());
3034 
3035         // We support memory retrieval, remember that.
3036         m_supports_mem_region = LazyBool::eLazyBoolYes;
3037     }
3038     else
3039     {
3040         if (log)
3041             log->Printf ("NativeProcessLinux::%s reusing %" PRIu64 " cached memory region entries", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
3042     }
3043 
3044     lldb::addr_t prev_base_address = 0;
3045 
3046     // FIXME start by finding the last region that is <= target address using binary search.  Data is sorted.
3047     // There can be a ton of regions on pthreads apps with lots of threads.
3048     for (auto it = m_mem_region_cache.begin(); it != m_mem_region_cache.end (); ++it)
3049     {
3050         MemoryRegionInfo &proc_entry_info = *it;
3051 
3052         // Sanity check assumption that /proc/{pid}/maps entries are ascending.
3053         assert ((proc_entry_info.GetRange ().GetRangeBase () >= prev_base_address) && "descending /proc/pid/maps entries detected, unexpected");
3054         prev_base_address = proc_entry_info.GetRange ().GetRangeBase ();
3055 
3056         // If the target address comes before this entry, indicate distance to next region.
3057         if (load_addr < proc_entry_info.GetRange ().GetRangeBase ())
3058         {
3059             range_info.GetRange ().SetRangeBase (load_addr);
3060             range_info.GetRange ().SetByteSize (proc_entry_info.GetRange ().GetRangeBase () - load_addr);
3061             range_info.SetReadable (MemoryRegionInfo::OptionalBool::eNo);
3062             range_info.SetWritable (MemoryRegionInfo::OptionalBool::eNo);
3063             range_info.SetExecutable (MemoryRegionInfo::OptionalBool::eNo);
3064 
3065             return error;
3066         }
3067         else if (proc_entry_info.GetRange ().Contains (load_addr))
3068         {
3069             // The target address is within the memory region we're processing here.
3070             range_info = proc_entry_info;
3071             return error;
3072         }
3073 
3074         // The target memory address comes somewhere after the region we just parsed.
3075     }
3076 
3077     // If we made it here, we didn't find an entry that contained the given address.
3078     error.SetErrorString ("address comes after final region");
3079 
3080     if (log)
3081         log->Printf ("NativeProcessLinux::%s failed to find map entry for address 0x%" PRIx64 ": %s", __FUNCTION__, load_addr, error.AsCString ());
3082 
3083     return error;
3084 }
3085 
3086 void
3087 NativeProcessLinux::DoStopIDBumped (uint32_t newBumpId)
3088 {
3089     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3090     if (log)
3091         log->Printf ("NativeProcessLinux::%s(newBumpId=%" PRIu32 ") called", __FUNCTION__, newBumpId);
3092 
3093     {
3094         Mutex::Locker locker (m_mem_region_cache_mutex);
3095         if (log)
3096             log->Printf ("NativeProcessLinux::%s clearing %" PRIu64 " entries from the cache", __FUNCTION__, static_cast<uint64_t> (m_mem_region_cache.size ()));
3097         m_mem_region_cache.clear ();
3098     }
3099 }
3100 
3101 Error
3102 NativeProcessLinux::AllocateMemory (
3103     lldb::addr_t size,
3104     uint32_t permissions,
3105     lldb::addr_t &addr)
3106 {
3107     // FIXME implementing this requires the equivalent of
3108     // InferiorCallPOSIX::InferiorCallMmap, which depends on
3109     // functional ThreadPlans working with Native*Protocol.
3110 #if 1
3111     return Error ("not implemented yet");
3112 #else
3113     addr = LLDB_INVALID_ADDRESS;
3114 
3115     unsigned prot = 0;
3116     if (permissions & lldb::ePermissionsReadable)
3117         prot |= eMmapProtRead;
3118     if (permissions & lldb::ePermissionsWritable)
3119         prot |= eMmapProtWrite;
3120     if (permissions & lldb::ePermissionsExecutable)
3121         prot |= eMmapProtExec;
3122 
3123     // TODO implement this directly in NativeProcessLinux
3124     // (and lift to NativeProcessPOSIX if/when that class is
3125     // refactored out).
3126     if (InferiorCallMmap(this, addr, 0, size, prot,
3127                          eMmapFlagsAnon | eMmapFlagsPrivate, -1, 0)) {
3128         m_addr_to_mmap_size[addr] = size;
3129         return Error ();
3130     } else {
3131         addr = LLDB_INVALID_ADDRESS;
3132         return Error("unable to allocate %" PRIu64 " bytes of memory with permissions %s", size, GetPermissionsAsCString (permissions));
3133     }
3134 #endif
3135 }
3136 
3137 Error
3138 NativeProcessLinux::DeallocateMemory (lldb::addr_t addr)
3139 {
3140     // FIXME see comments in AllocateMemory - required lower-level
3141     // bits not in place yet (ThreadPlans)
3142     return Error ("not implemented");
3143 }
3144 
3145 lldb::addr_t
3146 NativeProcessLinux::GetSharedLibraryInfoAddress ()
3147 {
3148 #if 1
3149     // punt on this for now
3150     return LLDB_INVALID_ADDRESS;
3151 #else
3152     // Return the image info address for the exe module
3153 #if 1
3154     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3155 
3156     ModuleSP module_sp;
3157     Error error = GetExeModuleSP (module_sp);
3158     if (error.Fail ())
3159     {
3160          if (log)
3161             log->Warning ("NativeProcessLinux::%s failed to retrieve exe module: %s", __FUNCTION__, error.AsCString ());
3162         return LLDB_INVALID_ADDRESS;
3163     }
3164 
3165     if (module_sp == nullptr)
3166     {
3167          if (log)
3168             log->Warning ("NativeProcessLinux::%s exe module returned was NULL", __FUNCTION__);
3169          return LLDB_INVALID_ADDRESS;
3170     }
3171 
3172     ObjectFileSP object_file_sp = module_sp->GetObjectFile ();
3173     if (object_file_sp == nullptr)
3174     {
3175          if (log)
3176             log->Warning ("NativeProcessLinux::%s exe module returned a NULL object file", __FUNCTION__);
3177          return LLDB_INVALID_ADDRESS;
3178     }
3179 
3180     return obj_file_sp->GetImageInfoAddress();
3181 #else
3182     Target *target = &GetTarget();
3183     ObjectFile *obj_file = target->GetExecutableModule()->GetObjectFile();
3184     Address addr = obj_file->GetImageInfoAddress(target);
3185 
3186     if (addr.IsValid())
3187         return addr.GetLoadAddress(target);
3188     return LLDB_INVALID_ADDRESS;
3189 #endif
3190 #endif // punt on this for now
3191 }
3192 
3193 size_t
3194 NativeProcessLinux::UpdateThreads ()
3195 {
3196     // The NativeProcessLinux monitoring threads are always up to date
3197     // with respect to thread state and they keep the thread list
3198     // populated properly. All this method needs to do is return the
3199     // thread count.
3200     Mutex::Locker locker (m_threads_mutex);
3201     return m_threads.size ();
3202 }
3203 
3204 bool
3205 NativeProcessLinux::GetArchitecture (ArchSpec &arch) const
3206 {
3207     arch = m_arch;
3208     return true;
3209 }
3210 
3211 Error
3212 NativeProcessLinux::GetSoftwareBreakpointSize (NativeRegisterContextSP context_sp, uint32_t &actual_opcode_size)
3213 {
3214     // FIXME put this behind a breakpoint protocol class that can be
3215     // set per architecture.  Need ARM, MIPS support here.
3216     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
3217     static const uint8_t g_i386_opcode [] = { 0xCC };
3218 
3219     switch (m_arch.GetMachine ())
3220     {
3221         case llvm::Triple::aarch64:
3222             actual_opcode_size = static_cast<uint32_t> (sizeof(g_aarch64_opcode));
3223             return Error ();
3224 
3225         case llvm::Triple::x86:
3226         case llvm::Triple::x86_64:
3227             actual_opcode_size = static_cast<uint32_t> (sizeof(g_i386_opcode));
3228             return Error ();
3229 
3230         default:
3231             assert(false && "CPU type not supported!");
3232             return Error ("CPU type not supported");
3233     }
3234 }
3235 
3236 Error
3237 NativeProcessLinux::SetBreakpoint (lldb::addr_t addr, uint32_t size, bool hardware)
3238 {
3239     if (hardware)
3240         return Error ("NativeProcessLinux does not support hardware breakpoints");
3241     else
3242         return SetSoftwareBreakpoint (addr, size);
3243 }
3244 
3245 Error
3246 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode (size_t trap_opcode_size_hint, size_t &actual_opcode_size, const uint8_t *&trap_opcode_bytes)
3247 {
3248     // FIXME put this behind a breakpoint protocol class that can be
3249     // set per architecture.  Need ARM, MIPS support here.
3250     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
3251     static const uint8_t g_i386_opcode [] = { 0xCC };
3252 
3253     switch (m_arch.GetMachine ())
3254     {
3255     case llvm::Triple::aarch64:
3256         trap_opcode_bytes = g_aarch64_opcode;
3257         actual_opcode_size = sizeof(g_aarch64_opcode);
3258         return Error ();
3259 
3260     case llvm::Triple::x86:
3261     case llvm::Triple::x86_64:
3262         trap_opcode_bytes = g_i386_opcode;
3263         actual_opcode_size = sizeof(g_i386_opcode);
3264         return Error ();
3265 
3266     default:
3267         assert(false && "CPU type not supported!");
3268         return Error ("CPU type not supported");
3269     }
3270 }
3271 
3272 #if 0
3273 ProcessMessage::CrashReason
3274 NativeProcessLinux::GetCrashReasonForSIGSEGV(const siginfo_t *info)
3275 {
3276     ProcessMessage::CrashReason reason;
3277     assert(info->si_signo == SIGSEGV);
3278 
3279     reason = ProcessMessage::eInvalidCrashReason;
3280 
3281     switch (info->si_code)
3282     {
3283     default:
3284         assert(false && "unexpected si_code for SIGSEGV");
3285         break;
3286     case SI_KERNEL:
3287         // Linux will occasionally send spurious SI_KERNEL codes.
3288         // (this is poorly documented in sigaction)
3289         // One way to get this is via unaligned SIMD loads.
3290         reason = ProcessMessage::eInvalidAddress; // for lack of anything better
3291         break;
3292     case SEGV_MAPERR:
3293         reason = ProcessMessage::eInvalidAddress;
3294         break;
3295     case SEGV_ACCERR:
3296         reason = ProcessMessage::ePrivilegedAddress;
3297         break;
3298     }
3299 
3300     return reason;
3301 }
3302 #endif
3303 
3304 
3305 #if 0
3306 ProcessMessage::CrashReason
3307 NativeProcessLinux::GetCrashReasonForSIGILL(const siginfo_t *info)
3308 {
3309     ProcessMessage::CrashReason reason;
3310     assert(info->si_signo == SIGILL);
3311 
3312     reason = ProcessMessage::eInvalidCrashReason;
3313 
3314     switch (info->si_code)
3315     {
3316     default:
3317         assert(false && "unexpected si_code for SIGILL");
3318         break;
3319     case ILL_ILLOPC:
3320         reason = ProcessMessage::eIllegalOpcode;
3321         break;
3322     case ILL_ILLOPN:
3323         reason = ProcessMessage::eIllegalOperand;
3324         break;
3325     case ILL_ILLADR:
3326         reason = ProcessMessage::eIllegalAddressingMode;
3327         break;
3328     case ILL_ILLTRP:
3329         reason = ProcessMessage::eIllegalTrap;
3330         break;
3331     case ILL_PRVOPC:
3332         reason = ProcessMessage::ePrivilegedOpcode;
3333         break;
3334     case ILL_PRVREG:
3335         reason = ProcessMessage::ePrivilegedRegister;
3336         break;
3337     case ILL_COPROC:
3338         reason = ProcessMessage::eCoprocessorError;
3339         break;
3340     case ILL_BADSTK:
3341         reason = ProcessMessage::eInternalStackError;
3342         break;
3343     }
3344 
3345     return reason;
3346 }
3347 #endif
3348 
3349 #if 0
3350 ProcessMessage::CrashReason
3351 NativeProcessLinux::GetCrashReasonForSIGFPE(const siginfo_t *info)
3352 {
3353     ProcessMessage::CrashReason reason;
3354     assert(info->si_signo == SIGFPE);
3355 
3356     reason = ProcessMessage::eInvalidCrashReason;
3357 
3358     switch (info->si_code)
3359     {
3360     default:
3361         assert(false && "unexpected si_code for SIGFPE");
3362         break;
3363     case FPE_INTDIV:
3364         reason = ProcessMessage::eIntegerDivideByZero;
3365         break;
3366     case FPE_INTOVF:
3367         reason = ProcessMessage::eIntegerOverflow;
3368         break;
3369     case FPE_FLTDIV:
3370         reason = ProcessMessage::eFloatDivideByZero;
3371         break;
3372     case FPE_FLTOVF:
3373         reason = ProcessMessage::eFloatOverflow;
3374         break;
3375     case FPE_FLTUND:
3376         reason = ProcessMessage::eFloatUnderflow;
3377         break;
3378     case FPE_FLTRES:
3379         reason = ProcessMessage::eFloatInexactResult;
3380         break;
3381     case FPE_FLTINV:
3382         reason = ProcessMessage::eFloatInvalidOperation;
3383         break;
3384     case FPE_FLTSUB:
3385         reason = ProcessMessage::eFloatSubscriptRange;
3386         break;
3387     }
3388 
3389     return reason;
3390 }
3391 #endif
3392 
3393 #if 0
3394 ProcessMessage::CrashReason
3395 NativeProcessLinux::GetCrashReasonForSIGBUS(const siginfo_t *info)
3396 {
3397     ProcessMessage::CrashReason reason;
3398     assert(info->si_signo == SIGBUS);
3399 
3400     reason = ProcessMessage::eInvalidCrashReason;
3401 
3402     switch (info->si_code)
3403     {
3404     default:
3405         assert(false && "unexpected si_code for SIGBUS");
3406         break;
3407     case BUS_ADRALN:
3408         reason = ProcessMessage::eIllegalAlignment;
3409         break;
3410     case BUS_ADRERR:
3411         reason = ProcessMessage::eIllegalAddress;
3412         break;
3413     case BUS_OBJERR:
3414         reason = ProcessMessage::eHardwareError;
3415         break;
3416     }
3417 
3418     return reason;
3419 }
3420 #endif
3421 
3422 void
3423 NativeProcessLinux::ServeOperation(OperationArgs *args)
3424 {
3425     NativeProcessLinux *monitor = args->m_monitor;
3426 
3427     // We are finised with the arguments and are ready to go.  Sync with the
3428     // parent thread and start serving operations on the inferior.
3429     sem_post(&args->m_semaphore);
3430 
3431     for(;;)
3432     {
3433         // wait for next pending operation
3434         if (sem_wait(&monitor->m_operation_pending))
3435         {
3436             if (errno == EINTR)
3437                 continue;
3438             assert(false && "Unexpected errno from sem_wait");
3439         }
3440 
3441         reinterpret_cast<Operation*>(monitor->m_operation)->Execute(monitor);
3442 
3443         // notify calling thread that operation is complete
3444         sem_post(&monitor->m_operation_done);
3445     }
3446 }
3447 
3448 void
3449 NativeProcessLinux::DoOperation(void *op)
3450 {
3451     Mutex::Locker lock(m_operation_mutex);
3452 
3453     m_operation = op;
3454 
3455     // notify operation thread that an operation is ready to be processed
3456     sem_post(&m_operation_pending);
3457 
3458     // wait for operation to complete
3459     while (sem_wait(&m_operation_done))
3460     {
3461         if (errno == EINTR)
3462             continue;
3463         assert(false && "Unexpected errno from sem_wait");
3464     }
3465 }
3466 
3467 Error
3468 NativeProcessLinux::ReadMemory (lldb::addr_t addr, void *buf, lldb::addr_t size, lldb::addr_t &bytes_read)
3469 {
3470     ReadOperation op(addr, buf, size, bytes_read);
3471     DoOperation(&op);
3472     return op.GetError ();
3473 }
3474 
3475 Error
3476 NativeProcessLinux::WriteMemory (lldb::addr_t addr, const void *buf, lldb::addr_t size, lldb::addr_t &bytes_written)
3477 {
3478     WriteOperation op(addr, buf, size, bytes_written);
3479     DoOperation(&op);
3480     return op.GetError ();
3481 }
3482 
3483 bool
3484 NativeProcessLinux::ReadRegisterValue(lldb::tid_t tid, uint32_t offset, const char* reg_name,
3485                                   uint32_t size, RegisterValue &value)
3486 {
3487     bool result;
3488     ReadRegOperation op(tid, offset, reg_name, value, result);
3489     DoOperation(&op);
3490     return result;
3491 }
3492 
3493 bool
3494 NativeProcessLinux::WriteRegisterValue(lldb::tid_t tid, unsigned offset,
3495                                    const char* reg_name, const RegisterValue &value)
3496 {
3497     bool result;
3498     WriteRegOperation op(tid, offset, reg_name, value, result);
3499     DoOperation(&op);
3500     return result;
3501 }
3502 
3503 bool
3504 NativeProcessLinux::ReadGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3505 {
3506     bool result;
3507     ReadGPROperation op(tid, buf, buf_size, result);
3508     DoOperation(&op);
3509     return result;
3510 }
3511 
3512 bool
3513 NativeProcessLinux::ReadFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3514 {
3515     bool result;
3516     ReadFPROperation op(tid, buf, buf_size, result);
3517     DoOperation(&op);
3518     return result;
3519 }
3520 
3521 bool
3522 NativeProcessLinux::ReadRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3523 {
3524     bool result;
3525     ReadRegisterSetOperation op(tid, buf, buf_size, regset, result);
3526     DoOperation(&op);
3527     return result;
3528 }
3529 
3530 bool
3531 NativeProcessLinux::WriteGPR(lldb::tid_t tid, void *buf, size_t buf_size)
3532 {
3533     bool result;
3534     WriteGPROperation op(tid, buf, buf_size, result);
3535     DoOperation(&op);
3536     return result;
3537 }
3538 
3539 bool
3540 NativeProcessLinux::WriteFPR(lldb::tid_t tid, void *buf, size_t buf_size)
3541 {
3542     bool result;
3543     WriteFPROperation op(tid, buf, buf_size, result);
3544     DoOperation(&op);
3545     return result;
3546 }
3547 
3548 bool
3549 NativeProcessLinux::WriteRegisterSet(lldb::tid_t tid, void *buf, size_t buf_size, unsigned int regset)
3550 {
3551     bool result;
3552     WriteRegisterSetOperation op(tid, buf, buf_size, regset, result);
3553     DoOperation(&op);
3554     return result;
3555 }
3556 
3557 bool
3558 NativeProcessLinux::Resume (lldb::tid_t tid, uint32_t signo)
3559 {
3560     bool result;
3561     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
3562 
3563     if (log)
3564         log->Printf ("NativeProcessLinux::%s() resuming thread = %"  PRIu64 " with signal %s", __FUNCTION__, tid,
3565                                  GetUnixSignals().GetSignalAsCString (signo));
3566     ResumeOperation op (tid, signo, result);
3567     DoOperation (&op);
3568     if (log)
3569         log->Printf ("NativeProcessLinux::%s() resuming result = %s", __FUNCTION__, result ? "true" : "false");
3570     return result;
3571 }
3572 
3573 bool
3574 NativeProcessLinux::SingleStep(lldb::tid_t tid, uint32_t signo)
3575 {
3576     bool result;
3577     SingleStepOperation op(tid, signo, result);
3578     DoOperation(&op);
3579     return result;
3580 }
3581 
3582 bool
3583 NativeProcessLinux::GetSignalInfo(lldb::tid_t tid, void *siginfo, int &ptrace_err)
3584 {
3585     bool result;
3586     SiginfoOperation op(tid, siginfo, result, ptrace_err);
3587     DoOperation(&op);
3588     return result;
3589 }
3590 
3591 bool
3592 NativeProcessLinux::GetEventMessage(lldb::tid_t tid, unsigned long *message)
3593 {
3594     bool result;
3595     EventMessageOperation op(tid, message, result);
3596     DoOperation(&op);
3597     return result;
3598 }
3599 
3600 lldb_private::Error
3601 NativeProcessLinux::Detach(lldb::tid_t tid)
3602 {
3603     lldb_private::Error error;
3604     if (tid != LLDB_INVALID_THREAD_ID)
3605     {
3606         DetachOperation op(tid, error);
3607         DoOperation(&op);
3608     }
3609     return error;
3610 }
3611 
3612 bool
3613 NativeProcessLinux::DupDescriptor(const char *path, int fd, int flags)
3614 {
3615     int target_fd = open(path, flags, 0666);
3616 
3617     if (target_fd == -1)
3618         return false;
3619 
3620     return (dup2(target_fd, fd) == -1) ? false : true;
3621 }
3622 
3623 void
3624 NativeProcessLinux::StopMonitoringChildProcess()
3625 {
3626     if (m_monitor_thread.IsJoinable())
3627     {
3628         m_monitor_thread.Cancel();
3629         m_monitor_thread.Join(nullptr);
3630     }
3631 }
3632 
3633 void
3634 NativeProcessLinux::StopMonitor()
3635 {
3636     StopMonitoringChildProcess();
3637     StopOpThread();
3638     sem_destroy(&m_operation_pending);
3639     sem_destroy(&m_operation_done);
3640 
3641     // TODO: validate whether this still holds, fix up comment.
3642     // Note: ProcessPOSIX passes the m_terminal_fd file descriptor to
3643     // Process::SetSTDIOFileDescriptor, which in turn transfers ownership of
3644     // the descriptor to a ConnectionFileDescriptor object.  Consequently
3645     // even though still has the file descriptor, we shouldn't close it here.
3646 }
3647 
3648 void
3649 NativeProcessLinux::StopOpThread()
3650 {
3651     if (!m_operation_thread.IsJoinable())
3652         return;
3653 
3654     m_operation_thread.Cancel();
3655     m_operation_thread.Join(nullptr);
3656 }
3657 
3658 bool
3659 NativeProcessLinux::HasThreadNoLock (lldb::tid_t thread_id)
3660 {
3661     for (auto thread_sp : m_threads)
3662     {
3663         assert (thread_sp && "thread list should not contain NULL threads");
3664         if (thread_sp->GetID () == thread_id)
3665         {
3666             // We have this thread.
3667             return true;
3668         }
3669     }
3670 
3671     // We don't have this thread.
3672     return false;
3673 }
3674 
3675 NativeThreadProtocolSP
3676 NativeProcessLinux::MaybeGetThreadNoLock (lldb::tid_t thread_id)
3677 {
3678     // CONSIDER organize threads by map - we can do better than linear.
3679     for (auto thread_sp : m_threads)
3680     {
3681         if (thread_sp->GetID () == thread_id)
3682             return thread_sp;
3683     }
3684 
3685     // We don't have this thread.
3686     return NativeThreadProtocolSP ();
3687 }
3688 
3689 bool
3690 NativeProcessLinux::StopTrackingThread (lldb::tid_t thread_id)
3691 {
3692     Mutex::Locker locker (m_threads_mutex);
3693     for (auto it = m_threads.begin (); it != m_threads.end (); ++it)
3694     {
3695         if (*it && ((*it)->GetID () == thread_id))
3696         {
3697             m_threads.erase (it);
3698             return true;
3699         }
3700     }
3701 
3702     // Didn't find it.
3703     return false;
3704 }
3705 
3706 NativeThreadProtocolSP
3707 NativeProcessLinux::AddThread (lldb::tid_t thread_id)
3708 {
3709     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3710 
3711     Mutex::Locker locker (m_threads_mutex);
3712 
3713     if (log)
3714     {
3715         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " adding thread with tid %" PRIu64,
3716                 __FUNCTION__,
3717                 GetID (),
3718                 thread_id);
3719     }
3720 
3721     assert (!HasThreadNoLock (thread_id) && "attempted to add a thread by id that already exists");
3722 
3723     // If this is the first thread, save it as the current thread
3724     if (m_threads.empty ())
3725         SetCurrentThreadID (thread_id);
3726 
3727     NativeThreadProtocolSP thread_sp (new NativeThreadLinux (this, thread_id));
3728     m_threads.push_back (thread_sp);
3729 
3730     return thread_sp;
3731 }
3732 
3733 NativeThreadProtocolSP
3734 NativeProcessLinux::GetOrCreateThread (lldb::tid_t thread_id, bool &created)
3735 {
3736     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
3737 
3738     Mutex::Locker locker (m_threads_mutex);
3739     if (log)
3740     {
3741         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " get/create thread with tid %" PRIu64,
3742                      __FUNCTION__,
3743                      GetID (),
3744                      thread_id);
3745     }
3746 
3747     // Retrieve the thread if it is already getting tracked.
3748     NativeThreadProtocolSP thread_sp = MaybeGetThreadNoLock (thread_id);
3749     if (thread_sp)
3750     {
3751         if (log)
3752             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread already tracked, returning",
3753                          __FUNCTION__,
3754                          GetID (),
3755                          thread_id);
3756         created = false;
3757         return thread_sp;
3758 
3759     }
3760 
3761     // Create the thread metadata since it isn't being tracked.
3762     if (log)
3763         log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": thread didn't exist, tracking now",
3764                      __FUNCTION__,
3765                      GetID (),
3766                      thread_id);
3767 
3768     thread_sp.reset (new NativeThreadLinux (this, thread_id));
3769     m_threads.push_back (thread_sp);
3770     created = true;
3771 
3772     return thread_sp;
3773 }
3774 
3775 Error
3776 NativeProcessLinux::FixupBreakpointPCAsNeeded (NativeThreadProtocolSP &thread_sp)
3777 {
3778     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_BREAKPOINTS));
3779 
3780     Error error;
3781 
3782     // Get a linux thread pointer.
3783     if (!thread_sp)
3784     {
3785         error.SetErrorString ("null thread_sp");
3786         if (log)
3787             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3788         return error;
3789     }
3790     NativeThreadLinux *const linux_thread_p = reinterpret_cast<NativeThreadLinux*> (thread_sp.get());
3791 
3792     // Find out the size of a breakpoint (might depend on where we are in the code).
3793     NativeRegisterContextSP context_sp = linux_thread_p->GetRegisterContext ();
3794     if (!context_sp)
3795     {
3796         error.SetErrorString ("cannot get a NativeRegisterContext for the thread");
3797         if (log)
3798             log->Printf ("NativeProcessLinux::%s failed: %s", __FUNCTION__, error.AsCString ());
3799         return error;
3800     }
3801 
3802     uint32_t breakpoint_size = 0;
3803     error = GetSoftwareBreakpointSize (context_sp, breakpoint_size);
3804     if (error.Fail ())
3805     {
3806         if (log)
3807             log->Printf ("NativeProcessLinux::%s GetBreakpointSize() failed: %s", __FUNCTION__, error.AsCString ());
3808         return error;
3809     }
3810     else
3811     {
3812         if (log)
3813             log->Printf ("NativeProcessLinux::%s breakpoint size: %" PRIu32, __FUNCTION__, breakpoint_size);
3814     }
3815 
3816     // First try probing for a breakpoint at a software breakpoint location: PC - breakpoint size.
3817     const lldb::addr_t initial_pc_addr = context_sp->GetPC ();
3818     lldb::addr_t breakpoint_addr = initial_pc_addr;
3819     if (breakpoint_size > static_cast<lldb::addr_t> (0))
3820     {
3821         // Do not allow breakpoint probe to wrap around.
3822         if (breakpoint_addr >= static_cast<lldb::addr_t> (breakpoint_size))
3823             breakpoint_addr -= static_cast<lldb::addr_t> (breakpoint_size);
3824     }
3825 
3826     // Check if we stopped because of a breakpoint.
3827     NativeBreakpointSP breakpoint_sp;
3828     error = m_breakpoint_list.GetBreakpoint (breakpoint_addr, breakpoint_sp);
3829     if (!error.Success () || !breakpoint_sp)
3830     {
3831         // We didn't find one at a software probe location.  Nothing to do.
3832         if (log)
3833             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " no lldb breakpoint found at current pc with adjustment: 0x%" PRIx64, __FUNCTION__, GetID (), breakpoint_addr);
3834         return Error ();
3835     }
3836 
3837     // If the breakpoint is not a software breakpoint, nothing to do.
3838     if (!breakpoint_sp->IsSoftwareBreakpoint ())
3839     {
3840         if (log)
3841             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " breakpoint found at 0x%" PRIx64 ", not software, nothing to adjust", __FUNCTION__, GetID (), breakpoint_addr);
3842         return Error ();
3843     }
3844 
3845     //
3846     // We have a software breakpoint and need to adjust the PC.
3847     //
3848 
3849     // Sanity check.
3850     if (breakpoint_size == 0)
3851     {
3852         // Nothing to do!  How did we get here?
3853         if (log)
3854             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);
3855         return Error ();
3856     }
3857 
3858     // Change the program counter.
3859     if (log)
3860         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);
3861 
3862     error = context_sp->SetPC (breakpoint_addr);
3863     if (error.Fail ())
3864     {
3865         if (log)
3866             log->Printf ("NativeProcessLinux::%s pid %" PRIu64 " tid %" PRIu64 ": failed to set PC: %s", __FUNCTION__, GetID (), linux_thread_p->GetID (), error.AsCString ());
3867         return error;
3868     }
3869 
3870     return error;
3871 }
3872