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_*
19 using simgrid::mc::remote;
21 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
28 // List of library which memory segments are not considered:
29 static const std::vector<std::string> filtered_libraries = {
32 #elif defined __FreeBSD__
35 "libkvm", /* kernel data access library */
36 "libprocstat", /* process and file information retrieval */
37 "libthr", /* thread library */
40 "libargp", /* workarounds for glibc-less systems */
41 "libasan", /* gcc sanitizers */
44 "libboost_context-mt",
45 "libboost_stacktrace_addr2line",
46 "libboost_stacktrace_backtrace",
80 "libkrb5support", /*odd behaviour on fedora rawhide ... remove these when fixed*/
105 "libtsan", /* gcc sanitizers */
106 "libubsan", /* gcc sanitizers */
115 static bool is_simgrid_lib(const std::string& libname)
117 return libname == "libsimgrid";
120 static bool is_filtered_lib(const std::string& libname)
122 return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
125 static std::string get_lib_name(const std::string& pathname)
127 std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
130 size_t pos = map_basename.rfind(".so");
131 if (pos != std::string::npos) {
132 // strip the extension (matching regex "\.so.*$")
133 libname.assign(map_basename, 0, pos);
135 // strip the version suffix (matching regex "-[.0-9-]*$")
137 pos = libname.rfind('-');
138 if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
147 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
149 auto* buffer = static_cast<char*>(buf);
150 ssize_t real_count = count;
152 ssize_t res = pread(fd, buffer, count, offset);
159 else if (errno != EINTR) {
160 perror("pread_whole");
167 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
169 const auto* buffer = static_cast<const char*>(buf);
170 ssize_t real_count = count;
172 ssize_t res = pwrite(fd, buffer, count, offset);
179 else if (errno != EINTR)
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;
189 static void zero_buffer_init()
191 int fd = open("/dev/zero", O_RDONLY);
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");
200 int open_vm(pid_t pid, int flags)
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;
209 return open(buffer, flags);
212 // ***** RemoteSimulation
214 RemoteSimulation::RemoteSimulation(pid_t pid) : AddressSpace(this), pid_(pid), running_(true) {}
216 void RemoteSimulation::init()
218 this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
219 this->init_memory_map_info();
221 int fd = open_vm(this->pid_, O_RDWR);
222 xbt_assert(fd >= 0, "Could not open file for process virtual address space");
223 this->memory_file = fd;
225 // Read std_heap (is a struct mdesc*):
226 const simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
227 xbt_assert(std_heap_var, "No heap information in the target process");
228 xbt_assert(std_heap_var->address, "No constant address for this variable");
229 this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address));
231 this->smx_actors_infos.clear();
232 this->smx_dead_actors_infos.clear();
233 this->unw_addr_space = simgrid::mc::UnwindContext::createUnwindAddressSpace();
234 this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
235 this->unw_underlying_context = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
238 RemoteSimulation::~RemoteSimulation()
240 if (this->memory_file >= 0)
241 close(this->memory_file);
243 if (this->unw_underlying_addr_space != unw_local_addr_space) {
244 if (this->unw_underlying_addr_space)
245 unw_destroy_addr_space(this->unw_underlying_addr_space);
246 if (this->unw_underlying_context)
247 _UPT_destroy(this->unw_underlying_context);
250 unw_destroy_addr_space(this->unw_addr_space);
253 /** Refresh the information about the process
255 * Do not use directly, this is used by the getters when appropriate
256 * in order to have fresh data.
258 void RemoteSimulation::refresh_heap()
260 // Read/dereference/refresh the std_heap pointer:
262 this->heap.reset(new s_xbt_mheap_t());
263 this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address));
264 this->cache_flags_ |= RemoteSimulation::cache_heap;
267 /** Refresh the information about the process
269 * Do not use directly, this is used by the getters when appropriate
270 * in order to have fresh data.
272 void RemoteSimulation::refresh_malloc_info()
274 // Refresh process->heapinfo:
275 if (this->cache_flags_ & RemoteSimulation::cache_malloc)
277 size_t count = this->heap->heaplimit + 1;
278 if (this->heap_info.size() < count)
279 this->heap_info.resize(count);
280 this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo));
281 this->cache_flags_ |= RemoteSimulation::cache_malloc;
284 /** @brief Finds the range of the different memory segments and binary paths */
285 void RemoteSimulation::init_memory_map_info()
287 XBT_DEBUG("Get debug information ...");
288 this->maestro_stack_start_ = nullptr;
289 this->maestro_stack_end_ = nullptr;
290 this->object_infos.resize(0);
291 this->binary_info = nullptr;
292 this->libsimgrid_info = nullptr;
294 std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
296 const char* current_name = nullptr;
298 this->object_infos.clear();
300 for (size_t i = 0; i < maps.size(); i++) {
301 simgrid::xbt::VmMap const& reg = maps[i];
302 const char* pathname = maps[i].pathname.c_str();
305 if (maps[i].pathname.empty()) {
306 current_name = nullptr;
310 // [stack], [vvar], [vsyscall], [vdso] ...
311 if (pathname[0] == '[') {
312 if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
313 this->maestro_stack_start_ = remote(reg.start_addr);
314 this->maestro_stack_end_ = remote(reg.end_addr);
316 current_name = nullptr;
320 if (current_name && strcmp(current_name, pathname) == 0)
323 current_name = pathname;
324 if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
327 const bool is_executable = not i;
329 if (not is_executable) {
330 libname = get_lib_name(pathname);
331 if (is_filtered_lib(libname)) {
336 std::shared_ptr<simgrid::mc::ObjectInformation> info =
337 simgrid::mc::createObjectInformation(this->memory_map_, pathname);
338 this->object_infos.push_back(info);
340 this->binary_info = info;
341 else if (is_simgrid_lib(libname))
342 this->libsimgrid_info = info;
345 // Resolve time (including across different objects):
346 for (auto const& object_info : this->object_infos)
347 postProcessObjectInformation(this, object_info.get());
349 xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
350 xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
352 XBT_DEBUG("Get debug information done !");
355 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteSimulation::find_object_info(RemotePtr<void> addr) const
357 for (auto const& object_info : this->object_infos)
358 if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
363 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_exec(RemotePtr<void> addr) const
365 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
366 if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
371 std::shared_ptr<ObjectInformation> RemoteSimulation::find_object_info_rw(RemotePtr<void> addr) const
373 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
374 if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
379 simgrid::mc::Frame* RemoteSimulation::find_function(RemotePtr<void> ip) const
381 std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
382 return info ? info->find_function((void*)ip.address()) : nullptr;
385 /** Find (one occurrence of) the named variable definition
387 const simgrid::mc::Variable* RemoteSimulation::find_variable(const char* name) const
389 // First lookup the variable in the executable shared object.
390 // A global variable used directly by the executable code from a library
391 // is reinstantiated in the executable memory .data/.bss.
392 // We need to look up the variable in the executable first.
393 if (this->binary_info) {
394 std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
395 const simgrid::mc::Variable* var = info->find_variable(name);
400 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
401 const simgrid::mc::Variable* var = info->find_variable(name);
409 void RemoteSimulation::read_variable(const char* name, void* target, size_t size) const
411 const simgrid::mc::Variable* var = this->find_variable(name);
412 xbt_assert(var, "Variable %s not found", name);
413 xbt_assert(var->address, "No simple location for this variable");
414 xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
415 xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
416 size, (size_t)var->type->full_type->byte_size);
417 this->read_bytes(target, size, remote(var->address));
420 std::string RemoteSimulation::read_string(RemotePtr<char> address) const
425 std::vector<char> res(128);
429 ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
430 if (c == -1 && errno == EINTR)
432 xbt_assert(c > 0, "Could not read string from remote process");
434 const void* p = memchr(res.data() + off, '\0', c);
436 return std::string(res.data());
439 if (off == (off_t)res.size())
440 res.resize(res.size() * 2);
444 void* RemoteSimulation::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address,
445 ReadOptions /*options*/) const
447 if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
448 xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
452 /** Write data to a process memory
454 * @param buffer local memory address (source)
455 * @param len data size
456 * @param address target process memory address (target)
458 void RemoteSimulation::write_bytes(const void* buffer, size_t len, RemotePtr<void> address) const
460 if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
461 xbt_die("Write to process %lli failed", (long long)this->pid_);
464 void RemoteSimulation::clear_bytes(RemotePtr<void> address, size_t len) const
466 pthread_once(&zero_buffer_flag, zero_buffer_init);
468 size_t s = len > zero_buffer_size ? zero_buffer_size : len;
469 this->write_bytes(zero_buffer, s, address);
470 address = remote((char*)address.address() + s);
475 void RemoteSimulation::ignore_region(std::uint64_t addr, std::size_t size)
477 IgnoredRegion region;
481 if (ignored_regions_.empty()) {
482 ignored_regions_.push_back(region);
486 unsigned int cursor = 0;
487 const IgnoredRegion* current_region = nullptr;
490 int end = ignored_regions_.size() - 1;
491 while (start <= end) {
492 cursor = (start + end) / 2;
493 current_region = &ignored_regions_[cursor];
494 if (current_region->addr == addr) {
495 if (current_region->size == size)
497 else if (current_region->size < size)
501 } else if (current_region->addr < addr)
507 std::size_t position;
508 if (current_region->addr == addr) {
509 if (current_region->size < size)
510 position = cursor + 1;
513 } else if (current_region->addr < addr)
514 position = cursor + 1;
517 ignored_regions_.insert(ignored_regions_.begin() + position, region);
520 void RemoteSimulation::ignore_heap(IgnoredHeapRegion const& region)
522 if (ignored_heap_.empty()) {
523 ignored_heap_.push_back(std::move(region));
527 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
530 size_type end = ignored_heap_.size() - 1;
532 // Binary search the position of insertion:
534 while (start <= end) {
535 cursor = start + (end - start) / 2;
536 auto const& current_region = ignored_heap_[cursor];
537 if (current_region.address == region.address)
539 else if (current_region.address < region.address)
541 else if (cursor != 0)
548 // Insert it mc_heap_ignore_region_t:
549 if (ignored_heap_[cursor].address < region.address)
551 ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
554 void RemoteSimulation::unignore_heap(void* address, size_t size)
556 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
559 size_type end = ignored_heap_.size() - 1;
563 while (start <= end) {
564 cursor = (start + end) / 2;
565 auto const& region = ignored_heap_[cursor];
566 if (region.address < address)
568 else if ((char*)region.address <= ((char*)address + size)) {
569 ignored_heap_.erase(ignored_heap_.begin() + cursor);
571 } else if (cursor != 0)
579 void RemoteSimulation::ignore_local_variable(const char* var_name, const char* frame_name) const
581 if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
582 frame_name = nullptr;
583 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
584 info->remove_local_variable(var_name, frame_name);
587 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::actors()
589 this->refresh_simix();
590 return smx_actors_infos;
593 std::vector<simgrid::mc::ActorInformation>& RemoteSimulation::dead_actors()
595 this->refresh_simix();
596 return smx_dead_actors_infos;
599 void RemoteSimulation::dump_stack() const
601 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
603 XBT_ERROR("Could not initialize ptrace address space");
607 void* context = _UPT_create(this->pid_);
608 if (context == nullptr) {
609 unw_destroy_addr_space(as);
610 XBT_ERROR("Could not initialize ptrace context");
615 if (unw_init_remote(&cursor, as, context) != 0) {
616 _UPT_destroy(context);
617 unw_destroy_addr_space(as);
618 XBT_ERROR("Could not initialiez ptrace cursor");
622 simgrid::mc::dumpStack(stderr, &cursor);
624 _UPT_destroy(context);
625 unw_destroy_addr_space(as);
628 } // namespace simgrid