+++ /dev/null
-/* Copyright (c) 2014-2022. The SimGrid Team. All rights reserved. */
-
-/* This program is free software; you can redistribute it and/or modify it
- * under the terms of the license (GNU LGPL) which comes with this package. */
-
-#define _FILE_OFFSET_BITS 64 /* needed for pread_whole to work as expected on 32bits */
-
-#include "src/mc/remote/RemoteProcess.hpp"
-
-#include "src/mc/sosp/Snapshot.hpp"
-#include "xbt/file.hpp"
-#include "xbt/log.h"
-
-#include <fcntl.h>
-#include <libunwind-ptrace.h>
-#include <sys/mman.h> // PROT_*
-
-#include <algorithm>
-#include <cerrno>
-#include <cstring>
-#include <memory>
-#include <mutex>
-#include <string>
-#include <string_view>
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_process, mc, "MC process information");
-
-namespace simgrid::mc {
-
-// ***** Helper stuff
-
-static bool is_filtered_lib(std::string_view libname)
-{
- return libname != "libsimgrid";
-}
-
-static std::string get_lib_name(const std::string& pathname)
-{
- std::string map_basename = simgrid::xbt::Path(pathname).get_base_name();
- std::string libname;
-
- if (size_t pos = map_basename.rfind(".so"); pos != std::string::npos) {
- // strip the extension (matching regex "\.so.*$")
- libname.assign(map_basename, 0, pos);
-
- // strip the version suffix (matching regex "-[.0-9-]*$")
- while (true) {
- pos = libname.rfind('-');
- if (pos == std::string::npos || libname.find_first_not_of(".0123456789", pos + 1) != std::string::npos)
- break;
- libname.erase(pos);
- }
- }
-
- return libname;
-}
-
-static ssize_t pread_whole(int fd, void* buf, size_t count, off_t offset)
-{
- auto* buffer = static_cast<char*>(buf);
- ssize_t real_count = count;
- while (count) {
- ssize_t res = pread(fd, buffer, count, offset);
- if (res > 0) {
- count -= res;
- buffer += res;
- offset += res;
- } else if (res == 0)
- return -1;
- else if (errno != EINTR) {
- XBT_ERROR("pread_whole: %s", strerror(errno));
- return -1;
- }
- }
- return real_count;
-}
-
-static ssize_t pwrite_whole(int fd, const void* buf, size_t count, off_t offset)
-{
- const auto* buffer = static_cast<const char*>(buf);
- ssize_t real_count = count;
- while (count) {
- ssize_t res = pwrite(fd, buffer, count, offset);
- if (res > 0) {
- count -= res;
- buffer += res;
- offset += res;
- } else if (res == 0)
- return -1;
- else if (errno != EINTR) {
- XBT_ERROR("pwrite_whole: %s", strerror(errno));
- return -1;
- }
- }
- return real_count;
-}
-
-int open_vm(pid_t pid, int flags)
-{
- std::string buffer = "/proc/" + std::to_string(pid) + "/mem";
- return open(buffer.c_str(), flags);
-}
-
-// ***** RemoteProcess
-
-RemoteProcess::RemoteProcess(pid_t pid) : AddressSpace(this), pid_(pid), running_(true) {}
-
-void RemoteProcess::init(xbt_mheap_t mmalloc_default_mdp, unsigned long* maxpid)
-{
- this->heap_address = remote(mmalloc_default_mdp);
- this->maxpid_addr_ = remote(maxpid);
-
- this->memory_map_ = simgrid::xbt::get_memory_map(this->pid_);
- this->init_memory_map_info();
-
- int fd = open_vm(this->pid_, O_RDWR);
- xbt_assert(fd >= 0, "Could not open file for process virtual address space");
- this->memory_file = fd;
-
- this->unw_addr_space = simgrid::mc::UnwindContext::createUnwindAddressSpace();
- this->unw_underlying_addr_space = simgrid::unw::create_addr_space();
- this->unw_underlying_context = simgrid::unw::create_context(this->unw_underlying_addr_space, this->pid_);
-}
-
-RemoteProcess::~RemoteProcess()
-{
- if (this->memory_file >= 0)
- close(this->memory_file);
-
- if (this->unw_underlying_addr_space != unw_local_addr_space) {
- if (this->unw_underlying_addr_space)
- unw_destroy_addr_space(this->unw_underlying_addr_space);
- if (this->unw_underlying_context)
- _UPT_destroy(this->unw_underlying_context);
- }
-
- unw_destroy_addr_space(this->unw_addr_space);
-}
-
-/** Refresh the information about the process
- *
- * Do not use directly, this is used by the getters when appropriate
- * in order to have fresh data.
- */
-void RemoteProcess::refresh_heap()
-{
- // Read/dereference/refresh the std_heap pointer:
- this->read(this->heap.get(), this->heap_address);
- this->cache_flags_ |= RemoteProcess::cache_heap;
-}
-
-/** Refresh the information about the process
- *
- * Do not use directly, this is used by the getters when appropriate
- * in order to have fresh data.
- * */
-void RemoteProcess::refresh_malloc_info()
-{
- // Refresh process->heapinfo:
- if (this->cache_flags_ & RemoteProcess::cache_malloc)
- return;
- size_t count = this->heap->heaplimit + 1;
- if (this->heap_info.size() < count)
- this->heap_info.resize(count);
- this->read_bytes(this->heap_info.data(), count * sizeof(malloc_info), remote(this->heap->heapinfo));
- this->cache_flags_ |= RemoteProcess::cache_malloc;
-}
-std::size_t RemoteProcess::get_remote_heap_bytes()
-{
- return mmalloc_get_bytes_used_remote(get_heap()->heaplimit, get_malloc_info());
-}
-
-/** @brief Finds the range of the different memory segments and binary paths */
-void RemoteProcess::init_memory_map_info()
-{
- XBT_DEBUG("Get debug information ...");
- this->maestro_stack_start_ = nullptr;
- this->maestro_stack_end_ = nullptr;
- this->object_infos.clear();
- this->binary_info = nullptr;
-
- std::vector<simgrid::xbt::VmMap> const& maps = this->memory_map_;
-
- const char* current_name = nullptr;
-
- for (size_t i = 0; i < maps.size(); i++) {
- simgrid::xbt::VmMap const& reg = maps[i];
- const char* pathname = maps[i].pathname.c_str();
-
- // Nothing to do
- if (maps[i].pathname.empty()) {
- current_name = nullptr;
- continue;
- }
-
- // [stack], [vvar], [vsyscall], [vdso] ...
- if (pathname[0] == '[') {
- if ((reg.prot & PROT_WRITE) && not memcmp(pathname, "[stack]", 7)) {
- this->maestro_stack_start_ = remote(reg.start_addr);
- this->maestro_stack_end_ = remote(reg.end_addr);
- }
- current_name = nullptr;
- continue;
- }
-
- if (current_name && strcmp(current_name, pathname) == 0)
- continue;
-
- current_name = pathname;
- if (not(reg.prot & PROT_READ) && (reg.prot & PROT_EXEC))
- continue;
-
- const bool is_executable = not i;
- std::string libname;
- if (not is_executable) {
- libname = get_lib_name(pathname);
- if (is_filtered_lib(libname)) {
- continue;
- }
- }
-
- std::shared_ptr<simgrid::mc::ObjectInformation> info =
- simgrid::mc::createObjectInformation(this->memory_map_, pathname);
- this->object_infos.push_back(info);
- if (is_executable)
- this->binary_info = info;
- }
-
- xbt_assert(this->maestro_stack_start_, "Did not find maestro_stack_start");
- xbt_assert(this->maestro_stack_end_, "Did not find maestro_stack_end");
-
- XBT_DEBUG("Get debug information done !");
-}
-
-std::shared_ptr<simgrid::mc::ObjectInformation> RemoteProcess::find_object_info(RemotePtr<void> addr) const
-{
- for (auto const& object_info : this->object_infos)
- if (addr.address() >= (std::uint64_t)object_info->start && addr.address() <= (std::uint64_t)object_info->end)
- return object_info;
- return nullptr;
-}
-
-std::shared_ptr<ObjectInformation> RemoteProcess::find_object_info_exec(RemotePtr<void> addr) const
-{
- for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
- if (addr.address() >= (std::uint64_t)info->start_exec && addr.address() <= (std::uint64_t)info->end_exec)
- return info;
- return nullptr;
-}
-
-std::shared_ptr<ObjectInformation> RemoteProcess::find_object_info_rw(RemotePtr<void> addr) const
-{
- for (std::shared_ptr<ObjectInformation> const& info : this->object_infos)
- if (addr.address() >= (std::uint64_t)info->start_rw && addr.address() <= (std::uint64_t)info->end_rw)
- return info;
- return nullptr;
-}
-
-simgrid::mc::Frame* RemoteProcess::find_function(RemotePtr<void> ip) const
-{
- std::shared_ptr<simgrid::mc::ObjectInformation> info = this->find_object_info_exec(ip);
- return info ? info->find_function((void*)ip.address()) : nullptr;
-}
-
-/** Find (one occurrence of) the named variable definition
- */
-const simgrid::mc::Variable* RemoteProcess::find_variable(const char* name) const
-{
- // First lookup the variable in the executable shared object.
- // A global variable used directly by the executable code from a library
- // is reinstantiated in the executable memory .data/.bss.
- // We need to look up the variable in the executable first.
- if (this->binary_info) {
- std::shared_ptr<simgrid::mc::ObjectInformation> const& info = this->binary_info;
- const simgrid::mc::Variable* var = info->find_variable(name);
- if (var)
- return var;
- }
-
- for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos) {
- const simgrid::mc::Variable* var = info->find_variable(name);
- if (var)
- return var;
- }
-
- return nullptr;
-}
-
-void RemoteProcess::read_variable(const char* name, void* target, size_t size) const
-{
- const simgrid::mc::Variable* var = this->find_variable(name);
- xbt_assert(var, "Variable %s not found", name);
- xbt_assert(var->address, "No simple location for this variable");
-
- if (not var->type->full_type) // Try to resolve this type. The needed ObjectInfo was maybe (lazily) loaded recently
- for (auto const& object_info : this->object_infos)
- postProcessObjectInformation(this, object_info.get());
- xbt_assert(var->type->full_type, "Partial type for %s (even after re-resolving types), cannot retrieve its size.",
- name);
- xbt_assert((size_t)var->type->full_type->byte_size == size, "Unexpected size for %s (expected %zu, received %zu).",
- name, size, (size_t)var->type->full_type->byte_size);
- this->read_bytes(target, size, remote(var->address));
-}
-
-std::string RemoteProcess::read_string(RemotePtr<char> address) const
-{
- if (not address)
- return {};
-
- std::vector<char> res(128);
- off_t off = 0;
-
- while (true) {
- ssize_t c = pread(this->memory_file, res.data() + off, res.size() - off, (off_t)address.address() + off);
- if (c == -1 && errno == EINTR)
- continue;
- xbt_assert(c > 0, "Could not read string from remote process");
-
- if (memchr(res.data() + off, '\0', c))
- return std::string(res.data());
-
- off += c;
- if (off == (off_t)res.size())
- res.resize(res.size() * 2);
- }
-}
-
-void* RemoteProcess::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, ReadOptions /*options*/) const
-{
- xbt_assert(pread_whole(this->memory_file, buffer, size, (size_t)address.address()) != -1,
- "Read at %p from process %lli failed", (void*)address.address(), (long long)this->pid_);
- return buffer;
-}
-
-/** Write data to a process memory
- *
- * @param buffer local memory address (source)
- * @param len data size
- * @param address target process memory address (target)
- */
-void RemoteProcess::write_bytes(const void* buffer, size_t len, RemotePtr<void> address) const
-{
- xbt_assert(pwrite_whole(this->memory_file, buffer, len, (size_t)address.address()) != -1,
- "Write to process %lli failed", (long long)this->pid_);
-}
-
-static void zero_buffer_init(const void** zero_buffer, size_t zero_buffer_size)
-{
- int fd = open("/dev/zero", O_RDONLY);
- xbt_assert(fd >= 0, "Could not open /dev/zero");
- *zero_buffer = mmap(nullptr, zero_buffer_size, PROT_READ, MAP_SHARED, fd, 0);
- xbt_assert(*zero_buffer != MAP_FAILED, "Could not map the zero buffer");
- close(fd);
-}
-
-void RemoteProcess::clear_bytes(RemotePtr<void> address, size_t len) const
-{
- static constexpr size_t zero_buffer_size = 10 * 4096;
- static const void* zero_buffer;
- static std::once_flag zero_buffer_flag;
-
- std::call_once(zero_buffer_flag, zero_buffer_init, &zero_buffer, zero_buffer_size);
- while (len) {
- size_t s = len > zero_buffer_size ? zero_buffer_size : len;
- this->write_bytes(zero_buffer, s, address);
- address = remote((char*)address.address() + s);
- len -= s;
- }
-}
-
-void RemoteProcess::ignore_region(std::uint64_t addr, std::size_t size)
-{
- IgnoredRegion region;
- region.addr = addr;
- region.size = size;
-
- auto pos = std::lower_bound(ignored_regions_.begin(), ignored_regions_.end(), region,
- [](auto const& reg1, auto const& reg2) {
- return reg1.addr < reg2.addr || (reg1.addr == reg2.addr && reg1.size < reg2.size);
- });
- if (pos == ignored_regions_.end() || pos->addr != addr || pos->size != size)
- ignored_regions_.insert(pos, region);
-}
-
-void RemoteProcess::ignore_heap(IgnoredHeapRegion const& region)
-{
- // Binary search the position of insertion:
- auto pos = std::lower_bound(ignored_heap_.begin(), ignored_heap_.end(), region.address,
- [](auto const& reg, auto const* addr) { return reg.address < addr; });
- if (pos == ignored_heap_.end() || pos->address != region.address) {
- // Insert it:
- ignored_heap_.insert(pos, region);
- }
-}
-
-void RemoteProcess::unignore_heap(void* address, size_t size)
-{
- // Binary search:
- auto pos = std::lower_bound(ignored_heap_.begin(), ignored_heap_.end(), address,
- [](auto const& reg, auto const* addr) { return reg.address < addr; });
- if (pos != ignored_heap_.end() && static_cast<char*>(pos->address) <= static_cast<char*>(address) + size)
- ignored_heap_.erase(pos);
-}
-
-void RemoteProcess::ignore_local_variable(const char* var_name, const char* frame_name) const
-{
- if (frame_name != nullptr && strcmp(frame_name, "*") == 0)
- frame_name = nullptr;
- for (std::shared_ptr<simgrid::mc::ObjectInformation> const& info : this->object_infos)
- info->remove_local_variable(var_name, frame_name);
-}
-
-void RemoteProcess::dump_stack() const
-{
- unw_addr_space_t as = unw_create_addr_space(&_UPT_accessors, BYTE_ORDER);
- if (as == nullptr) {
- XBT_ERROR("Could not initialize ptrace address space");
- return;
- }
-
- void* context = _UPT_create(this->pid_);
- if (context == nullptr) {
- unw_destroy_addr_space(as);
- XBT_ERROR("Could not initialize ptrace context");
- return;
- }
-
- unw_cursor_t cursor;
- if (unw_init_remote(&cursor, as, context) != 0) {
- _UPT_destroy(context);
- unw_destroy_addr_space(as);
- XBT_ERROR("Could not initialize ptrace cursor");
- return;
- }
-
- simgrid::mc::dumpStack(stderr, &cursor);
-
- _UPT_destroy(context);
- unw_destroy_addr_space(as);
-}
-} // namespace simgrid::mc
