src/mc/remote/RemoteClient.cpp

   1 /* Copyright (c) 2014-2018. 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 <algorithm>
   9 #include <cassert>
  10 #include <cerrno>
  11 #include <cstddef>
  12 #include <cstdint>
  13 #include <string>
  14 #include <vector>
  15
  16 #include <sys/ptrace.h>
  17
  18 #include <cstdio>
  19
  20 #include <fcntl.h>
  21 #include <sys/mman.h> // PROT_*
  22 #include <sys/types.h>
  23 #include <unistd.h>
  24
  25 #include <pthread.h>
  26
  27 #include <libgen.h>
  28
  29 #include <libunwind-ptrace.h>
  30 #include <libunwind.h>
  31
  32 #include "xbt/base.h"
  33 #include "xbt/file.hpp"
  34 #include "xbt/log.h"
  35 #include <xbt/mmalloc.h>
  36
  37 #include "src/mc/mc_smx.hpp"
  38 #include "src/mc/mc_unw.hpp"
  39 #include "src/mc/sosp/mc_snapshot.hpp"
  40
  41 #include "src/mc/AddressSpace.hpp"
  42 #include "src/mc/ObjectInformation.hpp"
  43 #include "src/mc/Variable.hpp"
  44 #include "src/mc/remote/RemoteClient.hpp"
  45
  46 using simgrid::mc::remote;
  47
  48 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
  49
  50 namespace simgrid {
  51 namespace mc {
  52
  53 // ***** Helper stuff
  54
  55 // List of library which memory segments are not considered:
  56 static const std::vector<std::string> filtered_libraries = {
  57 #ifdef __linux__
  58     "ld",
  59 #elif defined __FreeBSD__
  60     "ld-elf",
  61     "ld-elf32",
  62     "libkvm",      /* kernel data access library */
  63     "libprocstat", /* process and file information retrieval */
  64     "libthr",      /* thread library */
  65     "libutil",
  66 #endif
  67     "libargp", /* workarounds for glibc-less systems */
  68     "libasan", /* gcc sanitizers */
  69     "libboost_chrono",
  70     "libboost_context",
  71     "libboost_context-mt",
  72     "libboost_system",
  73     "libboost_thread",
  74     "libboost_timer",
  75     "libboost_unit_test_framework",
  76     "libbz2",
  77     "libc",
  78     "libc++",
  79     "libcdt",
  80     "libcgraph",
  81     "libcrypto",
  82     "libcxxrt",
  83     "libdl",
  84     "libdw",
  85     "libelf",
  86     "libevent",
  87     "libexecinfo",
  88     "libflang",
  89     "libflangrti",
  90     "libgcc_s",
  91     "libgfortran",
  92     "libimf",
  93     "libintlc",
  94     "libirng",
  95     "liblua5.1",
  96     "liblua5.3",
  97     "liblzma",
  98     "libm",
  99     "libomp",
 100     "libpapi",
 101     "libpfm",
 102     "libpthread",
 103     "libquadmath",
 104     "librt",
 105     "libstdc++",
 106     "libsvml",
 107     "libtsan",  /* gcc sanitizers */
 108     "libubsan", /* gcc sanitizers */
 109     "libunwind",
 110     "libunwind-ptrace",
 111     "libunwind-x86",
 112     "libunwind-x86_64",
 113     "libz"};
 114
 115 static bool is_simgrid_lib(const std::string& libname)
 116 {
 117   return libname == "libsimgrid";
 118 }
 119
 120 static bool is_filtered_lib(const std::string& libname)
 121 {
 122   return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
 123 }
 124
 125 static std::string get_lib_name(const std::string& pathname)
 126 {
 127   std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
 128   std::string libname;
 129
 130   size_t pos = map_basename.rfind(".so");
 131   if (pos != std::string::npos) {
 132     // strip the extension (matching regex "\.so.*$")
 133     libname.assign(map_basename, 0, pos);
 134
 135     // strip the version suffix (matching regex "-[.0-9-]*$")
 136     while (true) {
 137       pos = libname.rfind('-');
 138       if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
 139         break;
 140       libname.erase(pos);
 141     }
 142   }
 143
 144   return libname;
 145 }
 146
 147 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
 148 {
 149   char* buffer       = (char*)buf;
 150   ssize_t real_count = count;
 151   while (count) {
 152     ssize_t res = pread(fd, buffer, count, offset);
 153     if (res > 0) {
 154       count -= res;
 155       buffer += res;
 156       offset += res;
 157     } else if (res == 0)
 158       return -1;
 159     else if (errno != EINTR) {
 160       perror("pread_whole");
 161       return -1;
 162     }
 163   }
 164   return real_count;
 165 }
 166
 167 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
 168 {
 169   const char* buffer = (const char*)buf;
 170   ssize_t real_count = count;
 171   while (count) {
 172     ssize_t res = pwrite(fd, buffer, count, offset);
 173     if (res > 0) {
 174       count -= res;
 175       buffer += res;
 176       offset += res;
 177     } else if (res == 0)
 178       return -1;
 179     else if (errno != EINTR)
 180       return -1;
 181   }
 182   return real_count;
 183 }
 184
 185 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
 186 static const void* zero_buffer;
 187 static const size_t zero_buffer_size = 10 * 4096;
 188
 189 static void zero_buffer_init()
 190 {
 191   int fd = open("/dev/zero", O_RDONLY);
 192   if (fd < 0)
 193     xbt_die("Could not open /dev/zero");
 194   zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
 195   if (zero_buffer == MAP_FAILED)
 196     xbt_die("Could not map the zero buffer");
 197   close(fd);
 198 }
 199
 200 int open_vm(pid_t pid, int flags)
 201 {
 202   const size_t buffer_size = 30;
 203   char buffer[buffer_size];
 204   int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
 205   if (res < 0 || (size_t)res >= buffer_size) {
 206     errno = ENAMETOOLONG;
 207     return -1;
 208   }
 209   return open(buffer, flags);
 210 }
 211
 212 // ***** Process
 213
 214 RemoteClient::RemoteClient(pid_t pid, int sockfd) : AddressSpace(this), pid_(pid), channel_(sockfd), running_(true)
 215 {
 216 }
 217
 218 void RemoteClient::init()
 219 {
 220   this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
 221   this->init_memory_map_info();
 222
 223   int fd = open_vm(this->pid_, O_RDWR);
 224   if (fd < 0)
 225     xbt_die("Could not open file for process virtual address space");
 226   this->memory_file = fd;
 227
 228   // Read std_heap (is a struct mdesc*):
 229   simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
 230   if (not std_heap_var)
 231     xbt_die("No heap information in the target process");
 232   if (not std_heap_var->address)
 233     xbt_die("No constant address for this variable");
 234   this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address),
 235                    simgrid::mc::ProcessIndexDisabled);
 236
 237   this->smx_actors_infos.clear();
 238   this->smx_dead_actors_infos.clear();
 239   this->unw_addr_space            = simgrid::mc::UnwindContext::createUnwindAddressSpace();
 240   this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
 241   this->unw_underlying_context    = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
 242 }
 243
 244 RemoteClient::~RemoteClient()
 245 {
 246   if (this->memory_file >= 0)
 247     close(this->memory_file);
 248
 249   if (this->unw_underlying_addr_space != unw_local_addr_space) {
 250     if (this->unw_underlying_addr_space)
 251       unw_destroy_addr_space(this->unw_underlying_addr_space);
 252     if (this->unw_underlying_context)
 253       _UPT_destroy(this->unw_underlying_context);
 254   }
 255
 256   unw_destroy_addr_space(this->unw_addr_space);
 257 }
 258
 259 /** Refresh the information about the process
 260  *
 261  *  Do not use directly, this is used by the getters when appropriate
 262  *  in order to have fresh data.
 263  */
 264 void RemoteClient::refresh_heap()
 265 {
 266   // Read/dereference/refresh the std_heap pointer:
 267   if (not this->heap)
 268     this->heap = std::unique_ptr<s_xbt_mheap_t>(new s_xbt_mheap_t());
 269   this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address), simgrid::mc::ProcessIndexDisabled);
 270   this->cache_flags_ |= RemoteClient::cache_heap;
 271 }
 272
 273 /** Refresh the information about the process
 274  *
 275  *  Do not use direclty, this is used by the getters when appropriate
 276  *  in order to have fresh data.
 277  * */
 278 void RemoteClient::refresh_malloc_info()
 279 {
 280   // Refresh process->heapinfo:
 281   if (this->cache_flags_ & RemoteClient::cache_malloc)
 282     return;
 283   size_t count = this->heap->heaplimit + 1;
 284   if (this->heap_info.size() < count)
 285     this->heap_info.resize(count);
 286   this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo),
 287                    simgrid::mc::ProcessIndexDisabled);
 288   this->cache_flags_ |= RemoteClient::cache_malloc;
 289 }
 290
 291 /** @brief Finds the range of the different memory segments and binary paths */
 292 void RemoteClient::init_memory_map_info()
 293 {
 294   XBT_DEBUG("Get debug information ...");
 295   this->maestro_stack_start_ = nullptr;
 296   this->maestro_stack_end_   = nullptr;
 297   this->object_infos.resize(0);
 298   this->binary_info     = nullptr;
 299   this->libsimgrid_info = nullptr;
 300
 301   std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
 302
 303   const char* current_name = nullptr;
 304
 305   this->object_infos.clear();
 306
 307   for (size_t i = 0; i < maps.size(); i++) {
 308     simgrid::xbt::VmMap const& reg = maps[i];
 309     const char* pathname           = maps[i].pathname.c_str();
 310
 311     // Nothing to do
 312     if (maps[i].pathname.empty()) {
 313       current_name = nullptr;
 314       continue;
 315     }
 316
 317     // [stack], [vvar], [vsyscall], [vdso] ...
 318     if (pathname[0] == '[') {
 319       if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
 320         this->maestro_stack_start_ = remote(reg.start_addr);
 321         this->maestro_stack_end_   = remote(reg.end_addr);
 322       }
 323       current_name = nullptr;
 324       continue;
 325     }
 326
 327     if (current_name && strcmp(current_name, pathname) == 0)
 328       continue;
 329
 330     current_name = pathname;
 331     if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
 332       continue;
 333
 334     const bool is_executable = not i;
 335     std::string libname;
 336     if (not is_executable) {
 337       libname = get_lib_name(pathname);
 338       if (is_filtered_lib(libname)) {
 339         continue;
 340       }
 341     }
 342
 343     std::shared_ptr<simgrid::mc::ObjectInformation> info =
 344         simgrid::mc::createObjectInformation(this->memory_map_, pathname);
 345     this->object_infos.push_back(info);
 346     if (is_executable)
 347       this->binary_info = info;
 348     else if (is_simgrid_lib(libname))
 349       this->libsimgrid_info = info;
 350   }
 351
 352   // Resolve time (including across different objects):
 353   for (auto const& object_info : this->object_infos)
 354     postProcessObjectInformation(this, object_info.get());
 355
 356   xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
 357   xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
 358
 359   XBT_DEBUG("Get debug information done !");
 360 }
 361
 362 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteClient::find_object_info(RemotePtr<void> addr) const
 363 {
 364   for (auto const& object_info : this->object_infos)
 365     if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
 366       return object_info;
 367   return nullptr;
 368 }
 369
 370 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_exec(RemotePtr<void> addr) const
 371 {
 372   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
 373     if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
 374       return info;
 375   return nullptr;
 376 }
 377
 378 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_rw(RemotePtr<void> addr) const
 379 {
 380   for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
 381     if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
 382       return info;
 383   return nullptr;
 384 }
 385
 386 simgrid::mc::Frame* RemoteClient::find_function(RemotePtr<void> ip) const
 387 {
 388   std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
 389   return info ? info->find_function((void*)ip.address()) : nullptr;
 390 }
 391
 392 /** Find (one occurrence of) the named variable definition
 393  */
 394 simgrid::mc::Variable* RemoteClient::find_variable(const char* name) const
 395 {
 396   // First lookup the variable in the executable shared object.
 397   // A global variable used directly by the executable code from a library
 398   // is reinstanciated in the executable memory .data/.bss.
 399   // We need to look up the variable in the executable first.
 400   if (this->binary_info) {
 401     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
 402     simgrid::mc::Variable* var                                  = info->find_variable(name);
 403     if (var)
 404       return var;
 405   }
 406
 407   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
 408     simgrid::mc::Variable* var = info->find_variable(name);
 409     if (var)
 410       return var;
 411   }
 412
 413   return nullptr;
 414 }
 415
 416 void RemoteClient::read_variable(const char* name, void* target, size_t size) const
 417 {
 418   simgrid::mc::Variable* var = this->find_variable(name);
 419   xbt_assert(var->address, "No simple location for this variable");
 420   xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
 421   xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
 422              size, (size_t)var->type->full_type->byte_size);
 423   this->read_bytes(target, size, remote(var->address));
 424 }
 425
 426 std::string RemoteClient::read_string(RemotePtr<char> address) const
 427 {
 428   if (not address)
 429     return {};
 430
 431   std::vector<char> res(128);
 432   off_t off = 0;
 433
 434   while (1) {
 435     ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
 436     if (c == -1) {
 437       if (errno == EINTR)
 438         continue;
 439       else
 440         xbt_die("Could not read from from remote process");
 441     }
 442     if (c == 0)
 443       xbt_die("Could not read string from remote process");
 444
 445     void* p = memchr(res.data() + off, '\0', c);
 446     if (p)
 447       return std::string(res.data());
 448
 449     off += c;
 450     if (off == (off_t)res.size())
 451       res.resize(res.size() * 2);
 452   }
 453 }
 454
 455 const void* RemoteClient::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, int process_index,
 456                                      ReadOptions options) const
 457 {
 458 #if HAVE_SMPI
 459   if (process_index != simgrid::mc::ProcessIndexDisabled) {
 460     std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->find_object_info_rw(address);
 461     // Segment overlap is not handled.
 462     if (info.get() && this->privatized(*info)) {
 463       if (process_index < 0)
 464         xbt_die("Missing process index");
 465       if (process_index >= (int)MC_smpi_process_count())
 466         xbt_die("Invalid process index");
 467
 468       // Read smpi_privatization_regions from MCed:
 469       smpi_privatization_region_t remote_smpi_privatization_regions =
 470           mc_model_checker->process().read_variable<smpi_privatization_region_t>("smpi_privatization_regions");
 471
 472       s_smpi_privatization_region_t privatization_region =
 473           mc_model_checker->process().read<s_smpi_privatization_region_t>(
 474               remote(remote_smpi_privatization_regions + process_index));
 475
 476       // Address translation in the privatization segment:
 477       size_t offset = address.address() - (std::uint64_t)info->start_rw;
 478       address       = remote((char*)privatization_region.address + offset);
 479     }
 480   }
 481 #endif
 482   if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
 483     xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
 484   return buffer;
 485 }
 486
 487 /** Write data to a process memory
 488  *
 489  *  @param buffer   local memory address (source)
 490  *  @param len      data size
 491  *  @param address  target process memory address (target)
 492  */
 493 void RemoteClient::write_bytes(const void* buffer, size_t len, RemotePtr<void> address)
 494 {
 495   if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
 496     xbt_die("Write to process %lli failed", (long long)this->pid_);
 497 }
 498
 499 void RemoteClient::clear_bytes(RemotePtr<void> address, size_t len)
 500 {
 501   pthread_once(&zero_buffer_flag, zero_buffer_init);
 502   while (len) {
 503     size_t s = len > zero_buffer_size ? zero_buffer_size : len;
 504     this->write_bytes(zero_buffer, s, address);
 505     address = remote((char*)address.address() + s);
 506     len -= s;
 507   }
 508 }
 509
 510 void RemoteClient::ignore_region(std::uint64_t addr, std::size_t size)
 511 {
 512   IgnoredRegion region;
 513   region.addr = addr;
 514   region.size = size;
 515
 516   if (ignored_regions_.empty()) {
 517     ignored_regions_.push_back(region);
 518     return;
 519   }
 520
 521   unsigned int cursor           = 0;
 522   IgnoredRegion* current_region = nullptr;
 523
 524   int start = 0;
 525   int end   = ignored_regions_.size() - 1;
 526   while (start <= end) {
 527     cursor         = (start + end) / 2;
 528     current_region = &ignored_regions_[cursor];
 529     if (current_region->addr == addr) {
 530       if (current_region->size == size)
 531         return;
 532       else if (current_region->size < size)
 533         start = cursor + 1;
 534       else
 535         end = cursor - 1;
 536     } else if (current_region->addr < addr)
 537       start = cursor + 1;
 538     else
 539       end = cursor - 1;
 540   }
 541
 542   std::size_t position;
 543   if (current_region->addr == addr) {
 544     if (current_region->size < size)
 545       position = cursor + 1;
 546     else
 547       position = cursor;
 548   } else if (current_region->addr < addr)
 549     position = cursor + 1;
 550   else
 551     position = cursor;
 552   ignored_regions_.insert(ignored_regions_.begin() + position, region);
 553 }
 554
 555 void RemoteClient::ignore_heap(IgnoredHeapRegion const& region)
 556 {
 557   if (ignored_heap_.empty()) {
 558     ignored_heap_.push_back(std::move(region));
 559     return;
 560   }
 561
 562   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
 563
 564   size_type start = 0;
 565   size_type end   = ignored_heap_.size() - 1;
 566
 567   // Binary search the position of insertion:
 568   size_type cursor;
 569   while (start <= end) {
 570     cursor               = start + (end - start) / 2;
 571     auto& current_region = ignored_heap_[cursor];
 572     if (current_region.address == region.address)
 573       return;
 574     else if (current_region.address < region.address)
 575       start = cursor + 1;
 576     else if (cursor != 0)
 577       end = cursor - 1;
 578     // Avoid underflow:
 579     else
 580       break;
 581   }
 582
 583   // Insert it mc_heap_ignore_region_t:
 584   if (ignored_heap_[cursor].address < region.address)
 585     ++cursor;
 586   ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
 587 }
 588
 589 void RemoteClient::unignore_heap(void* address, size_t size)
 590 {
 591   typedef std::vector<IgnoredHeapRegion>::size_type size_type;
 592
 593   size_type start = 0;
 594   size_type end   = ignored_heap_.size() - 1;
 595
 596   // Binary search:
 597   size_type cursor;
 598   while (start <= end) {
 599     cursor       = (start + end) / 2;
 600     auto& region = ignored_heap_[cursor];
 601     if (region.address < address)
 602       start = cursor + 1;
 603     else if ((char*)region.address <= ((char*)address + size)) {
 604       ignored_heap_.erase(ignored_heap_.begin() + cursor);
 605       return;
 606     } else if (cursor != 0)
 607       end = cursor - 1;
 608     // Avoid underflow:
 609     else
 610       break;
 611   }
 612 }
 613
 614 void RemoteClient::ignore_local_variable(const char* var_name, const char* frame_name)
 615 {
 616   if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
 617     frame_name = nullptr;
 618   for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
 619     info->remove_local_variable(var_name, frame_name);
 620 }
 621
 622 std::vector<simgrid::mc::ActorInformation>& RemoteClient::actors()
 623 {
 624   this->refresh_simix();
 625   return smx_actors_infos;
 626 }
 627
 628 std::vector<simgrid::mc::ActorInformation>& RemoteClient::dead_actors()
 629 {
 630   this->refresh_simix();
 631   return smx_dead_actors_infos;
 632 }
 633
 634 void RemoteClient::dumpStack()
 635 {
 636   unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
 637   if (as == nullptr) {
 638     XBT_ERROR("Could not initialize ptrace address space");
 639     return;
 640   }
 641
 642   void* context = _UPT_create(this->pid_);
 643   if (context == nullptr) {
 644     unw_destroy_addr_space(as);
 645     XBT_ERROR("Could not initialize ptrace context");
 646     return;
 647   }
 648
 649   unw_cursor_t cursor;
 650   if (unw_init_remote(&cursor, as, context) != 0) {
 651     _UPT_destroy(context);
 652     unw_destroy_addr_space(as);
 653     XBT_ERROR("Could not initialiez ptrace cursor");
 654     return;
 655   }
 656
 657   simgrid::mc::dumpStack(stderr, cursor);
 658
 659   _UPT_destroy(context);
 660   unw_destroy_addr_space(as);
 661 }
 662
 663 bool RemoteClient::actor_is_enabled(aid_t pid)
 664 {
 665   s_mc_message_actor_enabled_t msg{MC_MESSAGE_ACTOR_ENABLED, pid};
 666   process()->getChannel().send(msg);
 667   char buff[MC_MESSAGE_LENGTH];
 668   ssize_t received = process()->getChannel().receive(buff, MC_MESSAGE_LENGTH, true);
 669   xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
 670   return ((s_mc_message_int_t*)buff)->value;
 671 }
 672 }
 673 }