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[simgrid.git] / src / mc / remote / RemoteClient.cpp
1 /* Copyright (c) 2014-2019. The SimGrid Team. All rights reserved.          */
2
3 /* This program is free software; you can redistribute it and/or modify it
4  * under the terms of the license (GNU LGPL) which comes with this package. */
5
6 #define _FILE_OFFSET_BITS 64 /* needed for pread_whole to work as expected on 32bits */
7
8 #include "src/mc/remote/RemoteClient.hpp"
9
10 #include "xbt/file.hpp"
11 #include "xbt/log.h"
12 #include "src/mc/mc_smx.hpp"
13 #include "src/mc/sosp/mc_snapshot.hpp"
14
15 #include <fcntl.h>
16 #include <libunwind-ptrace.h>
17 #include <sys/mman.h> // PROT_*
18
19 using simgrid::mc::remote;
20
21 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
22
23 namespace simgrid {
24 namespace mc {
25
26 // ***** Helper stuff
27
28 // List of library which memory segments are not considered:
29 static const std::vector<std::string> filtered_libraries = {
30 #ifdef __linux__
31     "ld",
32 #elif defined __FreeBSD__
33     "ld-elf",
34     "ld-elf32",
35     "libkvm",      /* kernel data access library */
36     "libprocstat", /* process and file information retrieval */
37     "libthr",      /* thread library */
38     "libutil",
39 #endif
40     "libargp", /* workarounds for glibc-less systems */
41     "libasan", /* gcc sanitizers */
42     "libboost_chrono",
43     "libboost_context",
44     "libboost_context-mt",
45     "libboost_stacktrace_backtrace",
46     "libboost_system",
47     "libboost_thread",
48     "libboost_timer",
49     "libbz2",
50     "libc",
51     "libc++",
52     "libcdt",
53     "libcgraph",
54     "libcrypto",
55     "libcxxrt",
56     "libdl",
57     "libdw",
58     "libelf",
59     "libevent",
60     "libexecinfo",
61     "libflang",
62     "libflangrti",
63     "libgcc_s",
64     "libgfortran",
65     "libimf",
66     "libintlc",
67     "libirng",
68     "liblua5.1",
69     "liblua5.3",
70     "liblzma",
71     "libm",
72     "libomp",
73     "libpapi",
74     "libpfm",
75     "libpgmath",
76     "libpthread",
77     "libquadmath",
78     "librt",
79     "libstdc++",
80     "libsvml",
81     "libtsan",  /* gcc sanitizers */
82     "libubsan", /* gcc sanitizers */
83     "libunwind",
84     "libunwind-ptrace",
85     "libunwind-x86",
86     "libunwind-x86_64",
87     "libz"};
88
89 static bool is_simgrid_lib(const std::string& libname)
90 {
91   return libname == "libsimgrid";
92 }
93
94 static bool is_filtered_lib(const std::string& libname)
95 {
96   return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
97 }
98
99 static std::string get_lib_name(const std::string& pathname)
100 {
101   std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
102   std::string libname;
103
104   size_t pos = map_basename.rfind(".so");
105   if (pos != std::string::npos) {
106     // strip the extension (matching regex "\.so.*$")
107     libname.assign(map_basename, 0, pos);
108
109     // strip the version suffix (matching regex "-[.0-9-]*$")
110     while (true) {
111       pos = libname.rfind('-');
112       if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
113         break;
114       libname.erase(pos);
115     }
116   }
117
118   return libname;
119 }
120
121 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
122 {
123   char* buffer       = (char*)buf;
124   ssize_t real_count = count;
125   while (count) {
126     ssize_t res = pread(fd, buffer, count, offset);
127     if (res > 0) {
128       count -= res;
129       buffer += res;
130       offset += res;
131     } else if (res == 0)
132       return -1;
133     else if (errno != EINTR) {
134       perror("pread_whole");
135       return -1;
136     }
137   }
138   return real_count;
139 }
140
141 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
142 {
143   const char* buffer = (const char*)buf;
144   ssize_t real_count = count;
145   while (count) {
146     ssize_t res = pwrite(fd, buffer, count, offset);
147     if (res > 0) {
148       count -= res;
149       buffer += res;
150       offset += res;
151     } else if (res == 0)
152       return -1;
153     else if (errno != EINTR)
154       return -1;
155   }
156   return real_count;
157 }
158
159 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
160 static const void* zero_buffer;
161 static const size_t zero_buffer_size = 10 * 4096;
162
163 static void zero_buffer_init()
164 {
165   int fd = open("/dev/zero", O_RDONLY);
166   if (fd < 0)
167     xbt_die("Could not open /dev/zero");
168   zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
169   if (zero_buffer == MAP_FAILED)
170     xbt_die("Could not map the zero buffer");
171   close(fd);
172 }
173
174 int open_vm(pid_t pid, int flags)
175 {
176   const size_t buffer_size = 30;
177   char buffer[buffer_size];
178   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
179   if (res < 0 || (size_t)res >= buffer_size) {
180     errno = ENAMETOOLONG;
181     return -1;
182   }
183   return open(buffer, flags);
184 }
185
186 // ***** Process
187
188 RemoteClient::RemoteClient(pid_t pid, int sockfd) : AddressSpace(this), pid_(pid), channel_(sockfd), running_(true)
189 {
190 }
191
192 void RemoteClient::init()
193 {
194   this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
195   this->init_memory_map_info();
196
197   int fd = open_vm(this->pid_, O_RDWR);
198   if (fd < 0)
199     xbt_die("Could not open file for process virtual address space");
200   this->memory_file = fd;
201
202   // Read std_heap (is a struct mdesc*):
203   simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
204   if (not std_heap_var)
205     xbt_die("No heap information in the target process");
206   if (not std_heap_var->address)
207     xbt_die("No constant address for this variable");
208   this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address),
209                    simgrid::mc::ProcessIndexDisabled);
210
211   this->smx_actors_infos.clear();
212   this->smx_dead_actors_infos.clear();
213   this->unw_addr_space            = simgrid::mc::UnwindContext::createUnwindAddressSpace();
214   this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
215   this->unw_underlying_context    = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
216 }
217
218 RemoteClient::~RemoteClient()
219 {
220   if (this->memory_file >= 0)
221     close(this->memory_file);
222
223   if (this->unw_underlying_addr_space != unw_local_addr_space) {
224     if (this->unw_underlying_addr_space)
225       unw_destroy_addr_space(this->unw_underlying_addr_space);
226     if (this->unw_underlying_context)
227       _UPT_destroy(this->unw_underlying_context);
228   }
229
230   unw_destroy_addr_space(this->unw_addr_space);
231 }
232
233 /** Refresh the information about the process
234  *
235  *  Do not use directly, this is used by the getters when appropriate
236  *  in order to have fresh data.
237  */
238 void RemoteClient::refresh_heap()
239 {
240   // Read/dereference/refresh the std_heap pointer:
241   if (not this->heap)
242     this->heap.reset(new s_xbt_mheap_t());
243   this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address), simgrid::mc::ProcessIndexDisabled);
244   this->cache_flags_ |= RemoteClient::cache_heap;
245 }
246
247 /** Refresh the information about the process
248  *
249  *  Do not use direclty, this is used by the getters when appropriate
250  *  in order to have fresh data.
251  * */
252 void RemoteClient::refresh_malloc_info()
253 {
254   // Refresh process->heapinfo:
255   if (this->cache_flags_ & RemoteClient::cache_malloc)
256     return;
257   size_t count = this->heap->heaplimit + 1;
258   if (this->heap_info.size() < count)
259     this->heap_info.resize(count);
260   this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo),
261                    simgrid::mc::ProcessIndexDisabled);
262   this->cache_flags_ |= RemoteClient::cache_malloc;
263 }
264
265 /** @brief Finds the range of the different memory segments and binary paths */
266 void RemoteClient::init_memory_map_info()
267 {
268   XBT_DEBUG("Get debug information ...");
269   this->maestro_stack_start_ = nullptr;
270   this->maestro_stack_end_   = nullptr;
271   this->object_infos.resize(0);
272   this->binary_info     = nullptr;
273   this->libsimgrid_info = nullptr;
274
275   std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
276
277   const char* current_name = nullptr;
278
279   this->object_infos.clear();
280
281   for (size_t i = 0; i < maps.size(); i++) {
282     simgrid::xbt::VmMap const& reg = maps[i];
283     const char* pathname           = maps[i].pathname.c_str();
284
285     // Nothing to do
286     if (maps[i].pathname.empty()) {
287       current_name = nullptr;
288       continue;
289     }
290
291     // [stack], [vvar], [vsyscall], [vdso] ...
292     if (pathname[0] == '[') {
293       if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
294         this->maestro_stack_start_ = remote(reg.start_addr);
295         this->maestro_stack_end_   = remote(reg.end_addr);
296       }
297       current_name = nullptr;
298       continue;
299     }
300
301     if (current_name && strcmp(current_name, pathname) == 0)
302       continue;
303
304     current_name = pathname;
305     if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
306       continue;
307
308     const bool is_executable = not i;
309     std::string libname;
310     if (not is_executable) {
311       libname = get_lib_name(pathname);
312       if (is_filtered_lib(libname)) {
313         continue;
314       }
315     }
316
317     std::shared_ptr<simgrid::mc::ObjectInformation> info =
318         simgrid::mc::createObjectInformation(this->memory_map_, pathname);
319     this->object_infos.push_back(info);
320     if (is_executable)
321       this->binary_info = info;
322     else if (is_simgrid_lib(libname))
323       this->libsimgrid_info = info;
324   }
325
326   // Resolve time (including across different objects):
327   for (auto const& object_info : this->object_infos)
328     postProcessObjectInformation(this, object_info.get());
329
330   xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
331   xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
332
333   XBT_DEBUG("Get debug information done !");
334 }
335
336 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteClient::find_object_info(RemotePtr<void> addr) const
337 {
338   for (auto const& object_info : this->object_infos)
339     if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
340       return object_info;
341   return nullptr;
342 }
343
344 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_exec(RemotePtr<void> addr) const
345 {
346   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
347     if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
348       return info;
349   return nullptr;
350 }
351
352 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_rw(RemotePtr<void> addr) const
353 {
354   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
355     if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
356       return info;
357   return nullptr;
358 }
359
360 simgrid::mc::Frame* RemoteClient::find_function(RemotePtr<void> ip) const
361 {
362   std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
363   return info ? info->find_function((void*)ip.address()) : nullptr;
364 }
365
366 /** Find (one occurrence of) the named variable definition
367  */
368 simgrid::mc::Variable* RemoteClient::find_variable(const char* name) const
369 {
370   // First lookup the variable in the executable shared object.
371   // A global variable used directly by the executable code from a library
372   // is reinstanciated in the executable memory .data/.bss.
373   // We need to look up the variable in the executable first.
374   if (this->binary_info) {
375     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
376     simgrid::mc::Variable* var                                  = info->find_variable(name);
377     if (var)
378       return var;
379   }
380
381   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
382     simgrid::mc::Variable* var = info->find_variable(name);
383     if (var)
384       return var;
385   }
386
387   return nullptr;
388 }
389
390 void RemoteClient::read_variable(const char* name, void* target, size_t size) const
391 {
392   simgrid::mc::Variable* var = this->find_variable(name);
393   xbt_assert(var->address, "No simple location for this variable");
394   xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
395   xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
396              size, (size_t)var->type->full_type->byte_size);
397   this->read_bytes(target, size, remote(var->address));
398 }
399
400 std::string RemoteClient::read_string(RemotePtr<char> address) const
401 {
402   if (not address)
403     return {};
404
405   std::vector<char> res(128);
406   off_t off = 0;
407
408   while (1) {
409     ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
410     if (c == -1) {
411       if (errno == EINTR)
412         continue;
413       else
414         xbt_die("Could not read from from remote process");
415     }
416     if (c == 0)
417       xbt_die("Could not read string from remote process");
418
419     void* p = memchr(res.data() + off, '\0', c);
420     if (p)
421       return std::string(res.data());
422
423     off += c;
424     if (off == (off_t)res.size())
425       res.resize(res.size() * 2);
426   }
427 }
428
429 const void* RemoteClient::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, int process_index,
430                                      ReadOptions /*options*/) const
431 {
432 #if HAVE_SMPI
433   if (process_index != simgrid::mc::ProcessIndexDisabled) {
434     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->find_object_info_rw(address);
435     // Segment overlap is not handled.
436     if (info.get() && this->privatized(*info)) {
437       if (process_index < 0)
438         xbt_die("Missing process index");
439       if (process_index >= (int)MC_smpi_process_count())
440         xbt_die("Invalid process index");
441
442       // Read smpi_privatization_regions from MCed:
443       smpi_privatization_region_t remote_smpi_privatization_regions =
444           mc_model_checker->process().read_variable<smpi_privatization_region_t>("smpi_privatization_regions");
445
446       s_smpi_privatization_region_t privatization_region =
447           mc_model_checker->process().read<s_smpi_privatization_region_t>(
448               remote(remote_smpi_privatization_regions + process_index));
449
450       // Address translation in the privatization segment:
451       size_t offset = address.address() - (std::uint64_t)info->start_rw;
452       address       = remote((char*)privatization_region.address + offset);
453     }
454   }
455 #endif
456   if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
457     xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
458   return buffer;
459 }
460
461 /** Write data to a process memory
462  *
463  *  @param buffer   local memory address (source)
464  *  @param len      data size
465  *  @param address  target process memory address (target)
466  */
467 void RemoteClient::write_bytes(const void* buffer, size_t len, RemotePtr<void> address)
468 {
469   if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
470     xbt_die("Write to process %lli failed", (long long)this->pid_);
471 }
472
473 void RemoteClient::clear_bytes(RemotePtr<void> address, size_t len)
474 {
475   pthread_once(&zero_buffer_flag, zero_buffer_init);
476   while (len) {
477     size_t s = len > zero_buffer_size ? zero_buffer_size : len;
478     this->write_bytes(zero_buffer, s, address);
479     address = remote((char*)address.address() + s);
480     len -= s;
481   }
482 }
483
484 void RemoteClient::ignore_region(std::uint64_t addr, std::size_t size)
485 {
486   IgnoredRegion region;
487   region.addr = addr;
488   region.size = size;
489
490   if (ignored_regions_.empty()) {
491     ignored_regions_.push_back(region);
492     return;
493   }
494
495   unsigned int cursor           = 0;
496   IgnoredRegion* current_region = nullptr;
497
498   int start = 0;
499   int end   = ignored_regions_.size() - 1;
500   while (start <= end) {
501     cursor         = (start + end) / 2;
502     current_region = &ignored_regions_[cursor];
503     if (current_region->addr == addr) {
504       if (current_region->size == size)
505         return;
506       else if (current_region->size < size)
507         start = cursor + 1;
508       else
509         end = cursor - 1;
510     } else if (current_region->addr < addr)
511       start = cursor + 1;
512     else
513       end = cursor - 1;
514   }
515
516   std::size_t position;
517   if (current_region->addr == addr) {
518     if (current_region->size < size)
519       position = cursor + 1;
520     else
521       position = cursor;
522   } else if (current_region->addr < addr)
523     position = cursor + 1;
524   else
525     position = cursor;
526   ignored_regions_.insert(ignored_regions_.begin() + position, region);
527 }
528
529 void RemoteClient::ignore_heap(IgnoredHeapRegion const& region)
530 {
531   if (ignored_heap_.empty()) {
532     ignored_heap_.push_back(std::move(region));
533     return;
534   }
535
536   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
537
538   size_type start = 0;
539   size_type end   = ignored_heap_.size() - 1;
540
541   // Binary search the position of insertion:
542   size_type cursor;
543   while (start <= end) {
544     cursor               = start + (end - start) / 2;
545     auto& current_region = ignored_heap_[cursor];
546     if (current_region.address == region.address)
547       return;
548     else if (current_region.address < region.address)
549       start = cursor + 1;
550     else if (cursor != 0)
551       end = cursor - 1;
552     // Avoid underflow:
553     else
554       break;
555   }
556
557   // Insert it mc_heap_ignore_region_t:
558   if (ignored_heap_[cursor].address < region.address)
559     ++cursor;
560   ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
561 }
562
563 void RemoteClient::unignore_heap(void* address, size_t size)
564 {
565   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
566
567   size_type start = 0;
568   size_type end   = ignored_heap_.size() - 1;
569
570   // Binary search:
571   size_type cursor;
572   while (start <= end) {
573     cursor       = (start + end) / 2;
574     auto& region = ignored_heap_[cursor];
575     if (region.address < address)
576       start = cursor + 1;
577     else if ((char*)region.address <= ((char*)address + size)) {
578       ignored_heap_.erase(ignored_heap_.begin() + cursor);
579       return;
580     } else if (cursor != 0)
581       end = cursor - 1;
582     // Avoid underflow:
583     else
584       break;
585   }
586 }
587
588 void RemoteClient::ignore_local_variable(const char* var_name, const char* frame_name)
589 {
590   if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
591     frame_name = nullptr;
592   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
593     info->remove_local_variable(var_name, frame_name);
594 }
595
596 std::vector<simgrid::mc::ActorInformation>& RemoteClient::actors()
597 {
598   this->refresh_simix();
599   return smx_actors_infos;
600 }
601
602 std::vector<simgrid::mc::ActorInformation>& RemoteClient::dead_actors()
603 {
604   this->refresh_simix();
605   return smx_dead_actors_infos;
606 }
607
608 void RemoteClient::dumpStack()
609 {
610   unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
611   if (as == nullptr) {
612     XBT_ERROR("Could not initialize ptrace address space");
613     return;
614   }
615
616   void* context = _UPT_create(this->pid_);
617   if (context == nullptr) {
618     unw_destroy_addr_space(as);
619     XBT_ERROR("Could not initialize ptrace context");
620     return;
621   }
622
623   unw_cursor_t cursor;
624   if (unw_init_remote(&cursor, as, context) != 0) {
625     _UPT_destroy(context);
626     unw_destroy_addr_space(as);
627     XBT_ERROR("Could not initialiez ptrace cursor");
628     return;
629   }
630
631   simgrid::mc::dumpStack(stderr, cursor);
632
633   _UPT_destroy(context);
634   unw_destroy_addr_space(as);
635 }
636
637 bool RemoteClient::actor_is_enabled(aid_t pid)
638 {
639   s_mc_message_actor_enabled_t msg{MC_MESSAGE_ACTOR_ENABLED, pid};
640   process()->getChannel().send(msg);
641   char buff[MC_MESSAGE_LENGTH];
642   ssize_t received = process()->getChannel().receive(buff, MC_MESSAGE_LENGTH, true);
643   xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
644   return ((s_mc_message_int_t*)buff)->value;
645 }
646 }
647 }