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_*
23 using simgrid::mc::remote;
25 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
32 // List of library which memory segments are not considered:
33 static const std::vector<std::string> filtered_libraries = {
36 #elif defined __FreeBSD__
39 "libkvm", /* kernel data access library */
40 "libprocstat", /* process and file information retrieval */
41 "libthr", /* thread library */
44 "libargp", /* workarounds for glibc-less systems */
45 "libasan", /* gcc sanitizers */
48 "libboost_context-mt",
49 "libboost_stacktrace_addr2line",
50 "libboost_stacktrace_backtrace",
91 "libkrb5support", /*odd behaviour on fedora rawhide ... remove these when fixed*/
122 "libtsan", /* gcc sanitizers */
123 "libubsan", /* gcc sanitizers */
132 static bool is_filtered_lib(const std::string& libname)
134 return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
137 static std::string get_lib_name(const std::string& pathname)
139 std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
142 size_t pos = map_basename.rfind(".so");
143 if (pos != std::string::npos) {
144 // strip the extension (matching regex "\.so.*$")
145 libname.assign(map_basename, 0, pos);
147 // strip the version suffix (matching regex "-[.0-9-]*$")
149 pos = libname.rfind('-');
150 if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
159 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
161 auto* buffer = static_cast<char*>(buf);
162 ssize_t real_count = count;
164 ssize_t res = pread(fd, buffer, count, offset);
171 else if (errno != EINTR) {
172 perror("pread_whole");
179 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
181 const auto* buffer = static_cast<const char*>(buf);
182 ssize_t real_count = count;
184 ssize_t res = pwrite(fd, buffer, count, offset);
191 else if (errno != EINTR)
197 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
198 static const void* zero_buffer;
199 static const size_t zero_buffer_size = 10 * 4096;
201 static void zero_buffer_init()
203 int fd = open("/dev/zero", O_RDONLY);
205 xbt_die("Could not open /dev/zero");
206 zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
207 if (zero_buffer == MAP_FAILED)
208 xbt_die("Could not map the zero buffer");
212 int open_vm(pid_t pid, int flags)
214 std::string buffer = "/proc/" + std::to_string(pid) + "/mem";
215 return open(buffer.c_str(), flags);
218 // ***** RemoteSimulation
220 RemoteSimulation::RemoteSimulation(pid_t pid) : AddressSpace(this), pid_(pid), running_(true) {}
222 void RemoteSimulation::init()
224 this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
225 this->init_memory_map_info();
227 int fd = open_vm(this->pid_, O_RDWR);
228 xbt_assert(fd >= 0, "Could not open file for process virtual address space");
229 this->memory_file = fd;
231 // Read std_heap (is a struct mdesc*):
232 const simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
233 xbt_assert(std_heap_var, "No heap information in the target process");
234 xbt_assert(std_heap_var->address, "No constant address for this variable");
235 this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address));
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_);
244 RemoteSimulation::~RemoteSimulation()
246 if (this->memory_file >= 0)
247 close(this->memory_file);
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);
256 unw_destroy_addr_space(this->unw_addr_space);
259 /** Refresh the information about the process
261 * Do not use directly, this is used by the getters when appropriate
262 * in order to have fresh data.
264 void RemoteSimulation::refresh_heap()
266 // Read/dereference/refresh the std_heap pointer:
268 this->heap = std::make_unique<s_xbt_mheap_t>();
269 this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address));
270 this->cache_flags_ |= RemoteSimulation::cache_heap;
273 /** Refresh the information about the process
275 * Do not use directly, this is used by the getters when appropriate
276 * in order to have fresh data.
278 void RemoteSimulation::refresh_malloc_info()
280 // Refresh process->heapinfo:
281 if (this->cache_flags_ & RemoteSimulation::cache_malloc)
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 this->cache_flags_ |= RemoteSimulation::cache_malloc;
290 /** @brief Finds the range of the different memory segments and binary paths */
291 void RemoteSimulation::init_memory_map_info()
293 XBT_DEBUG("Get debug information ...");
294 this->maestro_stack_start_ = nullptr;
295 this->maestro_stack_end_ = nullptr;
296 this->object_infos.resize(0);
297 this->binary_info = nullptr;
299 std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
301 const char* current_name = nullptr;
303 this->object_infos.clear();
305 for (size_t i = 0; i < maps.size(); i++) {
306 simgrid::xbt::VmMap const& reg = maps[i];
307 const char* pathname = maps[i].pathname.c_str();
310 if (maps[i].pathname.empty()) {
311 current_name = nullptr;
315 // [stack], [vvar], [vsyscall], [vdso] ...
316 if (pathname[0] == '[') {
317 if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
318 this->maestro_stack_start_ = remote(reg.start_addr);
319 this->maestro_stack_end_ = remote(reg.end_addr);
321 current_name = nullptr;
325 if (current_name && strcmp(current_name, pathname) == 0)
328 current_name = pathname;
329 if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
332 const bool is_executable = not i;
334 if (not is_executable) {
335 libname = get_lib_name(pathname);
336 if (is_filtered_lib(libname)) {
341 std::shared_ptr<simgrid::mc::ObjectInformation> info =
342 simgrid::mc::createObjectInformation(this->memory_map_, pathname);
343 this->object_infos.push_back(info);
345 this->binary_info = info;
348 // Resolve time (including across different objects):
349 for (auto const& object_info : this->object_infos)
350 postProcessObjectInformation(this, object_info.get());
352 xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
353 xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
355 XBT_DEBUG("Get debug information done !");
358 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteSimulation::find_object_info(RemotePtr<void> addr) const
360 for (auto const& object_info : this->object_infos)
361 if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
366 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_exec(RemotePtr<void> addr) const
368 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
369 if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
374 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_rw(RemotePtr<void> addr) const
376 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
377 if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
382 simgrid::mc::Frame* RemoteSimulation::find_function(RemotePtr<void> ip) const
384 std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
385 return info ? info->find_function((void*)ip.address()) : nullptr;
388 /** Find (one occurrence of) the named variable definition
390 const simgrid::mc::Variable* RemoteSimulation::find_variable(const char* name) const
392 // First lookup the variable in the executable shared object.
393 // A global variable used directly by the executable code from a library
394 // is reinstantiated in the executable memory .data/.bss.
395 // We need to look up the variable in the executable first.
396 if (this->binary_info) {
397 std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
398 const simgrid::mc::Variable* var = info->find_variable(name);
403 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
404 const simgrid::mc::Variable* var = info->find_variable(name);
412 void RemoteSimulation::read_variable(const char* name, void* target, size_t size) const
414 const simgrid::mc::Variable* var = this->find_variable(name);
415 xbt_assert(var, "Variable %s not found", name);
416 xbt_assert(var->address, "No simple location for this variable");
417 xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
418 xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
419 size, (size_t)var->type->full_type->byte_size);
420 this->read_bytes(target, size, remote(var->address));
423 std::string RemoteSimulation::read_string(RemotePtr<char> address) const
428 std::vector<char> res(128);
432 ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
433 if (c == -1 && errno == EINTR)
435 xbt_assert(c > 0, "Could not read string from remote process");
437 const void* p = memchr(res.data() + off, '\0', c);
439 return std::string(res.data());
442 if (off == (off_t)res.size())
443 res.resize(res.size() * 2);
447 void* RemoteSimulation::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address,
448 ReadOptions /*options*/) const
450 if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
451 xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
455 /** Write data to a process memory
457 * @param buffer local memory address (source)
458 * @param len data size
459 * @param address target process memory address (target)
461 void RemoteSimulation::write_bytes(const void* buffer, size_t len, RemotePtr<void> address) const
463 if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
464 xbt_die("Write to process %lli failed", (long long)this->pid_);
467 void RemoteSimulation::clear_bytes(RemotePtr<void> address, size_t len) const
469 pthread_once(&zero_buffer_flag, zero_buffer_init);
471 size_t s = len > zero_buffer_size ? zero_buffer_size : len;
472 this->write_bytes(zero_buffer, s, address);
473 address = remote((char*)address.address() + s);
478 void RemoteSimulation::ignore_region(std::uint64_t addr, std::size_t size)
480 IgnoredRegion region;
484 auto pos = std::lower_bound(ignored_regions_.begin(), ignored_regions_.end(), region,
485 [](auto const& reg1, auto const& reg2) {
486 return reg1.addr < reg2.addr || (reg1.addr == reg2.addr && reg1.size < reg2.size);
488 if (pos == ignored_regions_.end() || pos->addr != addr || pos->size != size)
489 ignored_regions_.insert(pos, region);
492 void RemoteSimulation::ignore_heap(IgnoredHeapRegion const& region)
494 // Binary search the position of insertion:
495 auto pos = std::lower_bound(ignored_heap_.begin(), ignored_heap_.end(), region.address,
496 [](auto const& reg, auto const* addr) { return reg.address < addr; });
497 if (pos == ignored_heap_.end() || pos->address != region.address) {
499 ignored_heap_.insert(pos, region);
503 void RemoteSimulation::unignore_heap(void* address, size_t size)
506 auto pos = std::lower_bound(ignored_heap_.begin(), ignored_heap_.end(), address,
507 [](auto const& reg, auto const* addr) { return reg.address < addr; });
508 if (pos != ignored_heap_.end() && static_cast<char*>(pos->address) <= static_cast<char*>(address) + size)
509 ignored_heap_.erase(pos);
512 void RemoteSimulation::ignore_local_variable(const char* var_name, const char* frame_name) const
514 if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
515 frame_name = nullptr;
516 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
517 info->remove_local_variable(var_name, frame_name);
520 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::actors()
522 this->refresh_simix();
523 return smx_actors_infos;
526 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::dead_actors()
528 this->refresh_simix();
529 return smx_dead_actors_infos;
532 void RemoteSimulation::dump_stack() const
534 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
536 XBT_ERROR("Could not initialize ptrace address space");
540 void* context = _UPT_create(this->pid_);
541 if (context == nullptr) {
542 unw_destroy_addr_space(as);
543 XBT_ERROR("Could not initialize ptrace context");
548 if (unw_init_remote(&cursor, as, context) != 0) {
549 _UPT_destroy(context);
550 unw_destroy_addr_space(as);
551 XBT_ERROR("Could not initialiez ptrace cursor");
555 simgrid::mc::dumpStack(stderr, &cursor);
557 _UPT_destroy(context);
558 unw_destroy_addr_space(as);
561 } // namespace simgrid