1 /* Copyright (c) 2014-2019. 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/RemoteClient.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",
82 "libtsan", /* gcc sanitizers */
83 "libubsan", /* gcc sanitizers */
90 static bool is_simgrid_lib(const std::string& libname)
92 return libname == "libsimgrid";
95 static bool is_filtered_lib(const std::string& libname)
97 return std::find(begin(filtered_libraries), end(filtered_libraries), libname) != end(filtered_libraries);
100 static std::string get_lib_name(const std::string& pathname)
102 std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
105 size_t pos = map_basename.rfind(".so");
106 if (pos != std::string::npos) {
107 // strip the extension (matching regex "\.so.*$")
108 libname.assign(map_basename, 0, pos);
110 // strip the version suffix (matching regex "-[.0-9-]*$")
112 pos = libname.rfind('-');
113 if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
122 static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
124 char* buffer = (char*)buf;
125 ssize_t real_count = count;
127 ssize_t res = pread(fd, buffer, count, offset);
134 else if (errno != EINTR) {
135 perror("pread_whole");
142 static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
144 const char* buffer = (const char*)buf;
145 ssize_t real_count = count;
147 ssize_t res = pwrite(fd, buffer, count, offset);
154 else if (errno != EINTR)
160 static pthread_once_t zero_buffer_flag = PTHREAD_ONCE_INIT;
161 static const void* zero_buffer;
162 static const size_t zero_buffer_size = 10 * 4096;
164 static void zero_buffer_init()
166 int fd = open("/dev/zero", O_RDONLY);
168 xbt_die("Could not open /dev/zero");
169 zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
170 if (zero_buffer == MAP_FAILED)
171 xbt_die("Could not map the zero buffer");
175 int open_vm(pid_t pid, int flags)
177 const size_t buffer_size = 30;
178 char buffer[buffer_size];
179 int res = snprintf(buffer, buffer_size, "/proc/%lli/mem", (long long)pid);
180 if (res < 0 || (size_t)res >= buffer_size) {
181 errno = ENAMETOOLONG;
184 return open(buffer, flags);
189 RemoteClient::RemoteClient(pid_t pid, int sockfd) : AddressSpace(this), pid_(pid), channel_(sockfd), running_(true)
193 void RemoteClient::init()
195 this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
196 this->init_memory_map_info();
198 int fd = open_vm(this->pid_, O_RDWR);
200 xbt_die("Could not open file for process virtual address space");
201 this->memory_file = fd;
203 // Read std_heap (is a struct mdesc*):
204 const simgrid::mc::Variable* std_heap_var = this->find_variable("__mmalloc_default_mdp");
205 if (not std_heap_var)
206 xbt_die("No heap information in the target process");
207 if (not std_heap_var->address)
208 xbt_die("No constant address for this variable");
209 this->read_bytes(&this->heap_address, sizeof(mdesc*), remote(std_heap_var->address));
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_);
218 RemoteClient::~RemoteClient()
220 if (this->memory_file >= 0)
221 close(this->memory_file);
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);
230 unw_destroy_addr_space(this->unw_addr_space);
233 /** Refresh the information about the process
235 * Do not use directly, this is used by the getters when appropriate
236 * in order to have fresh data.
238 void RemoteClient::refresh_heap()
240 // Read/dereference/refresh the std_heap pointer:
242 this->heap.reset(new s_xbt_mheap_t());
243 this->read_bytes(this->heap.get(), sizeof(mdesc), remote(this->heap_address));
244 this->cache_flags_ |= RemoteClient::cache_heap;
247 /** Refresh the information about the process
249 * Do not use direclty, this is used by the getters when appropriate
250 * in order to have fresh data.
252 void RemoteClient::refresh_malloc_info()
254 // Refresh process->heapinfo:
255 if (this->cache_flags_ & RemoteClient::cache_malloc)
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 this->cache_flags_ |= RemoteClient::cache_malloc;
264 /** @brief Finds the range of the different memory segments and binary paths */
265 void RemoteClient::init_memory_map_info()
267 XBT_DEBUG("Get debug information ...");
268 this->maestro_stack_start_ = nullptr;
269 this->maestro_stack_end_ = nullptr;
270 this->object_infos.resize(0);
271 this->binary_info = nullptr;
272 this->libsimgrid_info = nullptr;
274 std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
276 const char* current_name = nullptr;
278 this->object_infos.clear();
280 for (size_t i = 0; i < maps.size(); i++) {
281 simgrid::xbt::VmMap const& reg = maps[i];
282 const char* pathname = maps[i].pathname.c_str();
285 if (maps[i].pathname.empty()) {
286 current_name = nullptr;
290 // [stack], [vvar], [vsyscall], [vdso] ...
291 if (pathname[0] == '[') {
292 if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
293 this->maestro_stack_start_ = remote(reg.start_addr);
294 this->maestro_stack_end_ = remote(reg.end_addr);
296 current_name = nullptr;
300 if (current_name && strcmp(current_name, pathname) == 0)
303 current_name = pathname;
304 if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
307 const bool is_executable = not i;
309 if (not is_executable) {
310 libname = get_lib_name(pathname);
311 if (is_filtered_lib(libname)) {
316 std::shared_ptr<simgrid::mc::ObjectInformation> info =
317 simgrid::mc::createObjectInformation(this->memory_map_, pathname);
318 this->object_infos.push_back(info);
320 this->binary_info = info;
321 else if (is_simgrid_lib(libname))
322 this->libsimgrid_info = info;
325 // Resolve time (including across different objects):
326 for (auto const& object_info : this->object_infos)
327 postProcessObjectInformation(this, object_info.get());
329 xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
330 xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
332 XBT_DEBUG("Get debug information done !");
335 std::shared_ptr<simgrid::mc::ObjectInformation> RemoteClient::find_object_info(RemotePtr<void> addr) const
337 for (auto const& object_info : this->object_infos)
338 if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
343 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_exec(RemotePtr<void> addr) const
345 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
346 if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
351 std::shared_ptr<ObjectInformation> RemoteClient::find_object_info_rw(RemotePtr<void> addr) const
353 for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
354 if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
359 simgrid::mc::Frame* RemoteClient::find_function(RemotePtr<void> ip) const
361 std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
362 return info ? info->find_function((void*)ip.address()) : nullptr;
365 /** Find (one occurrence of) the named variable definition
367 const simgrid::mc::Variable* RemoteClient::find_variable(const char* name) const
369 // First lookup the variable in the executable shared object.
370 // A global variable used directly by the executable code from a library
371 // is reinstanciated in the executable memory .data/.bss.
372 // We need to look up the variable in the executable first.
373 if (this->binary_info) {
374 std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
375 const simgrid::mc::Variable* var = info->find_variable(name);
380 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
381 const simgrid::mc::Variable* var = info->find_variable(name);
389 void RemoteClient::read_variable(const char* name, void* target, size_t size) const
391 const simgrid::mc::Variable* var = this->find_variable(name);
392 xbt_assert(var->address, "No simple location for this variable");
393 xbt_assert(var->type->full_type, "Partial type for %s, cannot check size", name);
394 xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, was %zu)", name,
395 size, (size_t)var->type->full_type->byte_size);
396 this->read_bytes(target, size, remote(var->address));
399 std::string RemoteClient::read_string(RemotePtr<char> address) const
404 std::vector<char> res(128);
408 ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
413 xbt_die("Could not read from from remote process");
416 xbt_die("Could not read string from remote process");
418 void* p = memchr(res.data() + off, '\0', c);
420 return std::string(res.data());
423 if (off == (off_t)res.size())
424 res.resize(res.size() * 2);
428 const void* RemoteClient::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address,
429 ReadOptions /*options*/) const
431 if (pread_whole(this->memory_file, buffer, size, (size_t)address.address()) < 0)
432 xbt_die("Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
436 /** Write data to a process memory
438 * @param buffer local memory address (source)
439 * @param len data size
440 * @param address target process memory address (target)
442 void RemoteClient::write_bytes(const void* buffer, size_t len, RemotePtr<void> address)
444 if (pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) < 0)
445 xbt_die("Write to process %lli failed", (long long)this->pid_);
448 void RemoteClient::clear_bytes(RemotePtr<void> address, size_t len)
450 pthread_once(&zero_buffer_flag, zero_buffer_init);
452 size_t s = len > zero_buffer_size ? zero_buffer_size : len;
453 this->write_bytes(zero_buffer, s, address);
454 address = remote((char*)address.address() + s);
459 void RemoteClient::ignore_region(std::uint64_t addr, std::size_t size)
461 IgnoredRegion region;
465 if (ignored_regions_.empty()) {
466 ignored_regions_.push_back(region);
470 unsigned int cursor = 0;
471 IgnoredRegion* current_region = nullptr;
474 int end = ignored_regions_.size() - 1;
475 while (start <= end) {
476 cursor = (start + end) / 2;
477 current_region = &ignored_regions_[cursor];
478 if (current_region->addr == addr) {
479 if (current_region->size == size)
481 else if (current_region->size < size)
485 } else if (current_region->addr < addr)
491 std::size_t position;
492 if (current_region->addr == addr) {
493 if (current_region->size < size)
494 position = cursor + 1;
497 } else if (current_region->addr < addr)
498 position = cursor + 1;
501 ignored_regions_.insert(ignored_regions_.begin() + position, region);
504 void RemoteClient::ignore_heap(IgnoredHeapRegion const& region)
506 if (ignored_heap_.empty()) {
507 ignored_heap_.push_back(std::move(region));
511 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
514 size_type end = ignored_heap_.size() - 1;
516 // Binary search the position of insertion:
518 while (start <= end) {
519 cursor = start + (end - start) / 2;
520 auto& current_region = ignored_heap_[cursor];
521 if (current_region.address == region.address)
523 else if (current_region.address < region.address)
525 else if (cursor != 0)
532 // Insert it mc_heap_ignore_region_t:
533 if (ignored_heap_[cursor].address < region.address)
535 ignored_heap_.insert(ignored_heap_.begin() + cursor, region);
538 void RemoteClient::unignore_heap(void* address, size_t size)
540 typedef std::vector<IgnoredHeapRegion>::size_type size_type;
543 size_type end = ignored_heap_.size() - 1;
547 while (start <= end) {
548 cursor = (start + end) / 2;
549 auto& region = ignored_heap_[cursor];
550 if (region.address < address)
552 else if ((char*)region.address <= ((char*)address + size)) {
553 ignored_heap_.erase(ignored_heap_.begin() + cursor);
555 } else if (cursor != 0)
563 void RemoteClient::ignore_local_variable(const char* var_name, const char* frame_name)
565 if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
566 frame_name = nullptr;
567 for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
568 info->remove_local_variable(var_name, frame_name);
571 std::vector<simgrid::mc::ActorInformation>& RemoteClient::actors()
573 this->refresh_simix();
574 return smx_actors_infos;
577 std::vector<simgrid::mc::ActorInformation>& RemoteClient::dead_actors()
579 this->refresh_simix();
580 return smx_dead_actors_infos;
583 void RemoteClient::dump_stack()
585 unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
587 XBT_ERROR("Could not initialize ptrace address space");
591 void* context = _UPT_create(this->pid_);
592 if (context == nullptr) {
593 unw_destroy_addr_space(as);
594 XBT_ERROR("Could not initialize ptrace context");
599 if (unw_init_remote(&cursor, as, context) != 0) {
600 _UPT_destroy(context);
601 unw_destroy_addr_space(as);
602 XBT_ERROR("Could not initialiez ptrace cursor");
606 simgrid::mc::dumpStack(stderr, std::move(cursor));
608 _UPT_destroy(context);
609 unw_destroy_addr_space(as);
612 bool RemoteClient::actor_is_enabled(aid_t pid)
614 s_mc_message_actor_enabled_t msg{MC_MESSAGE_ACTOR_ENABLED, pid};
615 process()->get_channel().send(msg);
616 char buff[MC_MESSAGE_LENGTH];
617 ssize_t received = process()->get_channel().receive(buff, MC_MESSAGE_LENGTH, true);
618 xbt_assert(received == sizeof(s_mc_message_int_t), "Unexpected size in answer to ACTOR_ENABLED");
619 return ((s_mc_message_int_t*)buff)->value;