1 /* Copyright (c) 2014-2020. The SimGrid Team. All rights reserved. */
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. */
6 #define _FILE_OFFSET_BITS 64 /* needed for pread_whole to work as expected on 32bits */
8 #include "src/mc/remote/RemoteSimulation.hpp"
10 #include "src/mc/mc_smx.hpp"
11 #include "src/mc/sosp/Snapshot.hpp"
12 #include "xbt/file.hpp"
16 #include <libunwind-ptrace.h>
17 #include <sys/mman.h> // PROT_*
21 using simgrid::mc::remote;
23 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
30 // List of library which memory segments are not considered:
31 static const std::vector<std::string> filtered_libraries = {
34 #elif defined __FreeBSD__
37 "libkvm", /* kernel data access library */
38 "libprocstat", /* process and file information retrieval */
39 "libthr", /* thread library */
42 "libargp", /* workarounds for glibc-less systems */
43 "libasan", /* gcc sanitizers */
46 "libboost_context-mt",
47 "libboost_stacktrace_addr2line",
48 "libboost_stacktrace_backtrace",
89 "libkrb5support", /*odd behaviour on fedora rawhide ... remove these when fixed*/
120 "libtsan", /* gcc sanitizers */
121 "libubsan", /* gcc sanitizers */
130 static bool is_simgrid_lib(const std::string& libname)
132 return libname == "libsimgrid";
135 static bool is_filtered_lib(const std::string& libname)
137 return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
140 static std::string get_lib_name(const std::string& pathname)
142 std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
145 size_t pos = map_basename.rfind(".so");
146 if (pos != std::string::npos) {
147 // strip the extension (matching regex "\.so.*$")
148 libname.assign(map_basename, 0, pos);
150 // strip the version suffix (matching regex "-[.0-9-]*$")
152 pos = libname.rfind('-');
153 if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
162 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
164 auto* buffer = static_cast<char*>(buf);
165 ssize_t real_count = count;
167 ssize_t res = pread(fd, buffer, count, offset);
174 else if (errno != EINTR) {
175 perror("pread_whole");
182 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
184 const auto* buffer = static_cast<const char*>(buf);
185 ssize_t real_count = count;
187 ssize_t res = pwrite(fd, buffer, count, offset);
194 else if (errno != EINTR)
200 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
201 static const void* zero_buffer;
202 static const size_t zero_buffer_size = 10 * 4096;
204 static void zero_buffer_init()
206 int fd = open("/dev/zero", O_RDONLY);
208 xbt_die("Could not open /dev/zero");
209 zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
210 if (zero_buffer == MAP_FAILED)
211 xbt_die("Could not map the zero buffer");
215 int open_vm(pid_t pid, int flags)
217 const size_t buffer_size = 30;
218 char buffer[buffer_size];
219 int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
220 if (res < 0 || (size_t)res >= buffer_size) {
221 errno = ENAMETOOLONG;
224 return open(buffer, flags);
227 // ***** RemoteSimulation
229 RemoteSimulation::RemoteSimulation(pid_t pid) : AddressSpace(this), pid_(pid), running_(true) {}
231 void RemoteSimulation::init()
233 this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
234 this->init_memory_map_info();
236 int fd = open_vm(this->pid_, O_RDWR);
237 xbt_assert(fd >= 0, "Could not open file for process virtual address space");
238 this->memory_file = fd;
240 // Read std_heap (is a struct mdesc*):
241 const simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
242 xbt_assert(std_heap_var, "No heap information in the target process");
243 xbt_assert(std_heap_var->address, "No constant address for this variable");
244 this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address));
246 this->smx_actors_infos.clear();
247 this->smx_dead_actors_infos.clear();
248 this->unw_addr_space = simgrid::mc::UnwindContext::createUnwindAddressSpace();
249 this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
250 this->unw_underlying_context = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
253 RemoteSimulation::~RemoteSimulation()
255 if (this->memory_file >= 0)
256 close(this->memory_file);
258 if (this->unw_underlying_addr_space != unw_local_addr_space) {
259 if (this->unw_underlying_addr_space)
260 unw_destroy_addr_space(this->unw_underlying_addr_space);
261 if (this->unw_underlying_context)
262 _UPT_destroy(this->unw_underlying_context);
265 unw_destroy_addr_space(this->unw_addr_space);
268 /** Refresh the information about the process
270 * Do not use directly, this is used by the getters when appropriate
271 * in order to have fresh data.
273 void RemoteSimulation::refresh_heap()
275 // Read/dereference/refresh the std_heap pointer:
277 this->heap = std::make_unique<s_xbt_mheap_t>();
278 this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address));
279 this->cache_flags_ |= RemoteSimulation::cache_heap;
282 /** Refresh the information about the process
284 * Do not use directly, this is used by the getters when appropriate
285 * in order to have fresh data.
287 void RemoteSimulation::refresh_malloc_info()
289 // Refresh process->heapinfo:
290 if (this->cache_flags_ & RemoteSimulation::cache_malloc)
292 size_t count = this->heap->heaplimit + 1;
293 if (this->heap_info.size() < count)
294 this->heap_info.resize(count);
295 this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo));
296 this->cache_flags_ |= RemoteSimulation::cache_malloc;
299 /** @brief Finds the range of the different memory segments and binary paths */
300 void RemoteSimulation::init_memory_map_info()
302 XBT_DEBUG("Get debug information ...");
303 this->maestro_stack_start_ = nullptr;
304 this->maestro_stack_end_ = nullptr;
305 this->object_infos.resize(0);
306 this->binary_info = nullptr;
307 this->libsimgrid_info = nullptr;
309 std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
311 const char* current_name = nullptr;
313 this->object_infos.clear();
315 for (size_t i = 0; i < maps.size(); i++) {
316 simgrid::xbt::VmMap const& reg = maps[i];
317 const char* pathname = maps[i].pathname.c_str();
320 if (maps[i].pathname.empty()) {
321 current_name = nullptr;
325 // [stack], [vvar], [vsyscall], [vdso] ...
326 if (pathname[0] == '[') {
327 if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
328 this->maestro_stack_start_ = remote(reg.start_addr);
329 this->maestro_stack_end_ = remote(reg.end_addr);
331 current_name = nullptr;
335 if (current_name && strcmp(current_name, pathname) == 0)
338 current_name = pathname;
339 if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
342 const bool is_executable = not i;
344 if (not is_executable) {
345 libname = get_lib_name(pathname);
346 if (is_filtered_lib(libname)) {
351 std::shared_ptr<simgrid::mc::ObjectInformation> info =
352 simgrid::mc::createObjectInformation(this->memory_map_, pathname);
353 this->object_infos.push_back(info);
355 this->binary_info = info;
356 else if (is_simgrid_lib(libname))
357 this->libsimgrid_info = info;
360 // Resolve time (including across different objects):
361 for (auto const& object_info : this->object_infos)
362 postProcessObjectInformation(this, object_info.get());
364 xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
365 xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
367 XBT_DEBUG("Get debug information done !");
370 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteSimulation::find_object_info(RemotePtr<void> addr) const
372 for (auto const& object_info : this->object_infos)
373 if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
378 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_exec(RemotePtr<void> addr) const
380 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
381 if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
386 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_rw(RemotePtr<void> addr) const
388 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
389 if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
394 simgrid::mc::Frame* RemoteSimulation::find_function(RemotePtr<void> ip) const
396 std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
397 return info ? info->find_function((void*)ip.address()) : nullptr;
400 /** Find (one occurrence of) the named variable definition
402 const simgrid::mc::Variable* RemoteSimulation::find_variable(const char* name) const
404 // First lookup the variable in the executable shared object.
405 // A global variable used directly by the executable code from a library
406 // is reinstantiated in the executable memory .data/.bss.
407 // We need to look up the variable in the executable first.
408 if (this->binary_info) {
409 std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
410 const simgrid::mc::Variable* var = info->find_variable(name);
415 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
416 const simgrid::mc::Variable* var = info->find_variable(name);
424 void RemoteSimulation::read_variable(const char* name, void* target, size_t size) const
426 const simgrid::mc::Variable* var = this->find_variable(name);
427 xbt_assert(var, "Variable %s not found", name);
428 xbt_assert(var->address, "No simple location for this variable");
429 xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
430 xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
431 size, (size_t)var->type->full_type->byte_size);
432 this->read_bytes(target, size, remote(var->address));
435 std::string RemoteSimulation::read_string(RemotePtr<char> address) const
440 std::vector<char> res(128);
444 ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
445 if (c == -1 && errno == EINTR)
447 xbt_assert(c > 0, "Could not read string from remote process");
449 const void* p = memchr(res.data() + off, '\0', c);
451 return std::string(res.data());
454 if (off == (off_t)res.size())
455 res.resize(res.size() * 2);
459 void* RemoteSimulation::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address,
460 ReadOptions /*options*/) const
462 if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
463 xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
467 /** Write data to a process memory
469 * @param buffer local memory address (source)
470 * @param len data size
471 * @param address target process memory address (target)
473 void RemoteSimulation::write_bytes(const void* buffer, size_t len, RemotePtr<void> address) const
475 if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
476 xbt_die("Write to process %lli failed", (long long)this->pid_);
479 void RemoteSimulation::clear_bytes(RemotePtr<void> address, size_t len) const
481 pthread_once(&zero_buffer_flag, zero_buffer_init);
483 size_t s = len > zero_buffer_size ? zero_buffer_size : len;
484 this->write_bytes(zero_buffer, s, address);
485 address = remote((char*)address.address() + s);
490 void RemoteSimulation::ignore_region(std::uint64_t addr, std::size_t size)
492 IgnoredRegion region;
496 if (ignored_regions_.empty()) {
497 ignored_regions_.push_back(region);
501 unsigned int cursor = 0;
502 const IgnoredRegion* current_region = nullptr;
505 int end = ignored_regions_.size() - 1;
506 while (start <= end) {
507 cursor = (start + end) / 2;
508 current_region = &ignored_regions_[cursor];
509 if (current_region->addr == addr) {
510 if (current_region->size == size)
512 else if (current_region->size < size)
516 } else if (current_region->addr < addr)
522 std::size_t position;
523 if (current_region->addr == addr) {
524 if (current_region->size < size)
525 position = cursor + 1;
528 } else if (current_region->addr < addr)
529 position = cursor + 1;
532 ignored_regions_.insert(ignored_regions_.begin() + position, region);
535 void RemoteSimulation::ignore_heap(IgnoredHeapRegion const& region)
537 if (ignored_heap_.empty()) {
538 ignored_heap_.push_back(std::move(region));
542 using size_type = std::vector<IgnoredHeapRegion>::size_type;
545 size_type end = ignored_heap_.size() - 1;
547 // Binary search the position of insertion:
549 while (start <= end) {
550 cursor = start + (end - start) / 2;
551 auto const& current_region = ignored_heap_[cursor];
552 if (current_region.address == region.address)
554 else if (current_region.address < region.address)
556 else if (cursor != 0)
563 // Insert it mc_heap_ignore_region_t:
564 if (ignored_heap_[cursor].address < region.address)
566 ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
569 void RemoteSimulation::unignore_heap(void* address, size_t size)
571 using size_type = std::vector<IgnoredHeapRegion>::size_type;
574 size_type end = ignored_heap_.size() - 1;
578 while (start <= end) {
579 cursor = (start + end) / 2;
580 auto const& region = ignored_heap_[cursor];
581 if (region.address < address)
583 else if ((char*)region.address <= ((char*)address + size)) {
584 ignored_heap_.erase(ignored_heap_.begin() + cursor);
586 } else if (cursor != 0)
594 void RemoteSimulation::ignore_local_variable(const char* var_name, const char* frame_name) const
596 if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
597 frame_name = nullptr;
598 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
599 info->remove_local_variable(var_name, frame_name);
602 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::actors()
604 this->refresh_simix();
605 return smx_actors_infos;
608 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::dead_actors()
610 this->refresh_simix();
611 return smx_dead_actors_infos;
614 void RemoteSimulation::dump_stack() const
616 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
618 XBT_ERROR("Could not initialize ptrace address space");
622 void* context = _UPT_create(this->pid_);
623 if (context == nullptr) {
624 unw_destroy_addr_space(as);
625 XBT_ERROR("Could not initialize ptrace context");
630 if (unw_init_remote(&cursor, as, context) != 0) {
631 _UPT_destroy(context);
632 unw_destroy_addr_space(as);
633 XBT_ERROR("Could not initialiez ptrace cursor");
637 simgrid::mc::dumpStack(stderr, &cursor);
639 _UPT_destroy(context);
640 unw_destroy_addr_space(as);
643 } // namespace simgrid