ladybird/Userland/DevTools/UserspaceEmulator/Emulator.cpp
Andreas Kling 89483a9408 UserspaceEmulator: Implement a proper VM allocator
This patch brings Kernel::RangeAllocator to UserspaceEmulator in a
slightly simplified form.

It supports the basic three allocation types needed by virt$mmap():
allocate_anywhere, allocate_specific, and allocate_randomized.

Porting virt$mmap() and virt$munmap() to use the allocator makes
UE work correctly once again. :^)
2021-02-06 23:15:44 +01:00

1782 lines
55 KiB
C++

/*
* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "Emulator.h"
#include "MmapRegion.h"
#include "SimpleRegion.h"
#include "SoftCPU.h"
#include <AK/Debug.h>
#include <AK/Format.h>
#include <AK/LexicalPath.h>
#include <AK/MappedFile.h>
#include <AK/Random.h>
#include <LibELF/AuxiliaryVector.h>
#include <LibELF/Image.h>
#include <LibELF/Validation.h>
#include <LibPthread/pthread.h>
#include <LibX86/ELFSymbolProvider.h>
#include <fcntl.h>
#include <net/if.h>
#include <net/route.h>
#include <sched.h>
#include <serenity.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <syscall.h>
#include <termios.h>
#include <unistd.h>
#if defined(__GNUC__) && !defined(__clang__)
# pragma GCC optimize("O3")
#endif
namespace UserspaceEmulator {
static constexpr u32 stack_location = 0x10000000;
static constexpr size_t stack_size = 64 * KiB;
static Emulator* s_the;
Emulator& Emulator::the()
{
ASSERT(s_the);
return *s_the;
}
Emulator::Emulator(const String& executable_path, const Vector<String>& arguments, const Vector<String>& environment)
: m_executable_path(executable_path)
, m_arguments(arguments)
, m_environment(environment)
, m_mmu(*this)
, m_cpu(*this)
{
m_malloc_tracer = make<MallocTracer>(*this);
static constexpr FlatPtr userspace_range_base = 0x00800000;
static constexpr FlatPtr userspace_range_ceiling = 0xbe000000;
#ifdef UE_ASLR
static constexpr FlatPtr page_mask = 0xfffff000u;
size_t random_offset = (AK::get_random<u8>() % 32 * MiB) & page_mask;
FlatPtr base = userspace_range_base + random_offset;
#else
FlatPtr base = userspace_range_base;
#endif
m_range_allocator.initialize_with_range(VirtualAddress(base), userspace_range_ceiling - base);
ASSERT(!s_the);
s_the = this;
// setup_stack(arguments, environment);
register_signal_handlers();
setup_signal_trampoline();
}
Vector<ELF::AuxiliaryValue> Emulator::generate_auxiliary_vector(FlatPtr load_base, FlatPtr entry_eip, String executable_path, int executable_fd) const
{
// FIXME: This is not fully compatible with the auxiliary vector the kernel generates, this is just the bare
// minimum to get the loader going.
Vector<ELF::AuxiliaryValue> auxv;
// PHDR/EXECFD
// PH*
auxv.append({ ELF::AuxiliaryValue::PageSize, PAGE_SIZE });
auxv.append({ ELF::AuxiliaryValue::BaseAddress, (void*)load_base });
auxv.append({ ELF::AuxiliaryValue::Entry, (void*)entry_eip });
// FIXME: Don't hard code this? We might support other platforms later.. (e.g. x86_64)
auxv.append({ ELF::AuxiliaryValue::Platform, "i386" });
auxv.append({ ELF::AuxiliaryValue::ExecFilename, executable_path });
auxv.append({ ELF::AuxiliaryValue::ExecFileDescriptor, executable_fd });
auxv.append({ ELF::AuxiliaryValue::Null, 0L });
return auxv;
}
void Emulator::setup_stack(Vector<ELF::AuxiliaryValue> aux_vector)
{
auto stack_region = make<SimpleRegion>(stack_location, stack_size);
stack_region->set_stack(true);
m_mmu.add_region(move(stack_region));
m_cpu.set_esp(shadow_wrap_as_initialized<u32>(stack_location + stack_size));
Vector<u32> argv_entries;
for (auto& argument : m_arguments) {
m_cpu.push_string(argument.characters());
argv_entries.append(m_cpu.esp().value());
}
Vector<u32> env_entries;
for (auto& variable : m_environment) {
m_cpu.push_string(variable.characters());
env_entries.append(m_cpu.esp().value());
}
for (auto& auxv : aux_vector) {
if (!auxv.optional_string.is_empty()) {
m_cpu.push_string(auxv.optional_string.characters());
auxv.auxv.a_un.a_ptr = (void*)m_cpu.esp().value();
}
}
for (ssize_t i = aux_vector.size() - 1; i >= 0; --i) {
auto& value = aux_vector[i].auxv;
m_cpu.push_buffer((const u8*)&value, sizeof(value));
}
m_cpu.push32(shadow_wrap_as_initialized<u32>(0)); // char** envp = { envv_entries..., nullptr }
for (ssize_t i = env_entries.size() - 1; i >= 0; --i)
m_cpu.push32(shadow_wrap_as_initialized(env_entries[i]));
u32 envp = m_cpu.esp().value();
m_cpu.push32(shadow_wrap_as_initialized<u32>(0)); // char** argv = { argv_entries..., nullptr }
for (ssize_t i = argv_entries.size() - 1; i >= 0; --i)
m_cpu.push32(shadow_wrap_as_initialized(argv_entries[i]));
u32 argv = m_cpu.esp().value();
m_cpu.push32(shadow_wrap_as_initialized<u32>(0)); // (alignment)
u32 argc = argv_entries.size();
m_cpu.push32(shadow_wrap_as_initialized(envp));
m_cpu.push32(shadow_wrap_as_initialized(argv));
m_cpu.push32(shadow_wrap_as_initialized(argc));
m_cpu.push32(shadow_wrap_as_initialized<u32>(0)); // (alignment)
}
bool Emulator::load_elf()
{
auto file_or_error = MappedFile::map(m_executable_path);
if (file_or_error.is_error()) {
reportln("Unable to map {}: {}", m_executable_path, file_or_error.error());
return false;
}
auto elf_image_data = file_or_error.value()->bytes();
ELF::Image executable_elf(elf_image_data);
if (!executable_elf.is_dynamic()) {
// FIXME: Support static objects
ASSERT_NOT_REACHED();
}
String interpreter_path;
if (!ELF::validate_program_headers(*(const Elf32_Ehdr*)elf_image_data.data(), elf_image_data.size(), (const u8*)elf_image_data.data(), elf_image_data.size(), &interpreter_path)) {
reportln("failed to validate ELF file");
return false;
}
ASSERT(!interpreter_path.is_null());
dbgln("interpreter: {}", interpreter_path);
auto interpreter_file_or_error = MappedFile::map(interpreter_path);
ASSERT(!interpreter_file_or_error.is_error());
auto interpreter_image_data = interpreter_file_or_error.value()->bytes();
ELF::Image interpreter_image(interpreter_image_data);
constexpr FlatPtr interpreter_load_offset = 0x08000000;
interpreter_image.for_each_program_header([&](const ELF::Image::ProgramHeader& program_header) {
// Loader is not allowed to have its own TLS regions
ASSERT(program_header.type() != PT_TLS);
if (program_header.type() == PT_LOAD) {
auto region = make<SimpleRegion>(program_header.vaddr().offset(interpreter_load_offset).get(), program_header.size_in_memory());
if (program_header.is_executable() && !program_header.is_writable())
region->set_text(true);
memcpy(region->data(), program_header.raw_data(), program_header.size_in_image());
memset(region->shadow_data(), 0x01, program_header.size_in_memory());
if (program_header.is_executable()) {
m_loader_text_base = region->base();
m_loader_text_size = region->size();
}
mmu().add_region(move(region));
return IterationDecision::Continue;
}
return IterationDecision::Continue;
});
auto entry_point = interpreter_image.entry().offset(interpreter_load_offset).get();
m_cpu.set_eip(entry_point);
// executable_fd will be used by the loader
int executable_fd = open(m_executable_path.characters(), O_RDONLY);
if (executable_fd < 0)
return false;
auto aux_vector = generate_auxiliary_vector(interpreter_load_offset, entry_point, m_executable_path, executable_fd);
setup_stack(move(aux_vector));
return true;
}
int Emulator::exec()
{
// X86::ELFSymbolProvider symbol_provider(*m_elf);
X86::ELFSymbolProvider* symbol_provider = nullptr;
bool trace = false;
while (!m_shutdown) {
m_cpu.save_base_eip();
auto insn = X86::Instruction::from_stream(m_cpu, true, true);
if (trace)
outln("{:p} \033[33;1m{}\033[0m", m_cpu.base_eip(), insn.to_string(m_cpu.base_eip(), symbol_provider));
(m_cpu.*insn.handler())(insn);
if (trace)
m_cpu.dump();
if (m_pending_signals)
dispatch_one_pending_signal();
}
if (auto* tracer = malloc_tracer())
tracer->dump_leak_report();
return m_exit_status;
}
Vector<FlatPtr> Emulator::raw_backtrace()
{
Vector<FlatPtr, 128> backtrace;
backtrace.append(m_cpu.base_eip());
// FIXME: Maybe do something if the backtrace has uninitialized data in the frame chain.
u32 frame_ptr = m_cpu.ebp().value();
while (frame_ptr) {
u32 ret_ptr = m_mmu.read32({ 0x23, frame_ptr + 4 }).value();
if (!ret_ptr)
break;
backtrace.append(ret_ptr);
frame_ptr = m_mmu.read32({ 0x23, frame_ptr }).value();
}
return backtrace;
}
const MmapRegion* Emulator::find_text_region(FlatPtr address)
{
const MmapRegion* matching_region = nullptr;
mmu().for_each_region([&](auto& region) {
if (!is<MmapRegion>(region))
return IterationDecision::Continue;
const auto& mmap_region = static_cast<const MmapRegion&>(region);
if (!(mmap_region.is_executable() && address >= mmap_region.base() && address < mmap_region.base() + mmap_region.size()))
return IterationDecision::Continue;
matching_region = &mmap_region;
return IterationDecision::Break;
});
return matching_region;
}
String Emulator::create_backtrace_line(FlatPtr address)
{
String minimal = String::format("=={%d}== %p", getpid(), (void*)address);
const auto* region = find_text_region(address);
if (!region)
return minimal;
auto separator_index = region->name().index_of(":");
if (!separator_index.has_value())
return minimal;
String lib_name = region->name().substring(0, separator_index.value());
String lib_path = lib_name;
if (region->name().contains(".so"))
lib_path = String::formatted("/usr/lib/{}", lib_path);
if (!m_dynamic_library_cache.contains(lib_path)) {
auto file_or_error = MappedFile::map(lib_path);
if (file_or_error.is_error())
return minimal;
auto debug_info = make<Debug::DebugInfo>(make<ELF::Image>(file_or_error.value()->bytes()));
m_dynamic_library_cache.set(lib_path, CachedELF { file_or_error.release_value(), move(debug_info) });
}
auto it = m_dynamic_library_cache.find(lib_path);
auto& elf = it->value.debug_info->elf();
String symbol = elf.symbolicate(address - region->base());
auto line_without_source_info = String::format("=={%d}== %p [%s]: %s", getpid(), (void*)address, lib_name.characters(), symbol.characters());
auto source_position = it->value.debug_info->get_source_position(address - region->base());
if (source_position.has_value())
return String::format("=={%d}== %p [%s]: %s (\033[34;1m%s\033[0m:%zu)", getpid(), (void*)address, lib_name.characters(), symbol.characters(), LexicalPath(source_position.value().file_path).basename().characters(), source_position.value().line_number);
return line_without_source_info;
}
void Emulator::dump_backtrace(const Vector<FlatPtr>& backtrace)
{
for (auto& address : backtrace) {
reportln("{}", create_backtrace_line(address));
}
}
void Emulator::dump_backtrace()
{
dump_backtrace(raw_backtrace());
}
u32 Emulator::virt_syscall(u32 function, u32 arg1, u32 arg2, u32 arg3)
{
#if SPAM_DEBUG
reportln("Syscall: {} ({:x})", Syscall::to_string((Syscall::Function)function), function);
#endif
switch (function) {
case SC_chdir:
return virt$chdir(arg1, arg2);
case SC_dup2:
return virt$dup2(arg1, arg2);
case SC_get_stack_bounds:
return virt$get_stack_bounds(arg1, arg2);
case SC_access:
return virt$access(arg1, arg2, arg3);
case SC_waitid:
return virt$waitid(arg1);
case SC_getcwd:
return virt$getcwd(arg1, arg2);
case SC_ttyname:
return virt$ttyname(arg1, arg2, arg3);
case SC_getpgrp:
return virt$getpgrp();
case SC_getpgid:
return virt$getpgid(arg1);
case SC_setpgid:
return virt$setpgid(arg1, arg2);
case SC_execve:
return virt$execve(arg1);
case SC_sigaction:
return virt$sigaction(arg1, arg2, arg3);
case SC_sigreturn:
return virt$sigreturn();
case SC_stat:
return virt$stat(arg1);
case SC_realpath:
return virt$realpath(arg1);
case SC_gethostname:
return virt$gethostname(arg1, arg2);
case SC_ioctl:
return virt$ioctl(arg1, arg2, arg3);
case SC_get_dir_entries:
return virt$get_dir_entries(arg1, arg2, arg3);
case SC_profiling_enable:
return virt$profiling_enable(arg1);
case SC_profiling_disable:
return virt$profiling_disable(arg1);
case SC_disown:
return virt$disown(arg1);
case SC_purge:
return virt$purge(arg1);
case SC_mmap:
return virt$mmap(arg1);
case SC_mount:
return virt$mount(arg1);
case SC_munmap:
return virt$munmap(arg1, arg2);
case SC_mremap:
return virt$mremap(arg1);
case SC_gettid:
return virt$gettid();
case SC_getpid:
return virt$getpid();
case SC_getsid:
return virt$getsid(arg1);
case SC_pledge:
return virt$pledge(arg1);
case SC_unveil:
return virt$unveil(arg1);
case SC_getuid:
return virt$getuid();
case SC_geteuid:
return virt$geteuid();
case SC_getgid:
return virt$getgid();
case SC_getegid:
return virt$getegid();
case SC_setuid:
return virt$setuid(arg1);
case SC_setgid:
return virt$setgid(arg2);
case SC_close:
return virt$close(arg1);
case SC_fstat:
return virt$fstat(arg1, arg2);
case SC_mkdir:
return virt$mkdir(arg1, arg2, arg3);
case SC_unlink:
return virt$unlink(arg1, arg2);
case SC_write:
return virt$write(arg1, arg2, arg3);
case SC_read:
return virt$read(arg1, arg2, arg3);
case SC_mprotect:
return virt$mprotect(arg1, arg2, arg3);
case SC_madvise:
return virt$madvise(arg1, arg2, arg3);
case SC_anon_create:
return virt$anon_create(arg1, arg2);
case SC_sendfd:
return virt$sendfd(arg1, arg2);
case SC_recvfd:
return virt$recvfd(arg1);
case SC_open:
return virt$open(arg1);
case SC_pipe:
return virt$pipe(arg1, arg2);
case SC_fcntl:
return virt$fcntl(arg1, arg2, arg3);
case SC_getgroups:
return virt$getgroups(arg1, arg2);
case SC_setgroups:
return virt$setgroups(arg1, arg2);
case SC_lseek:
return virt$lseek(arg1, arg2, arg3);
case SC_socket:
return virt$socket(arg1, arg2, arg3);
case SC_getsockopt:
return virt$getsockopt(arg1);
case SC_get_process_name:
return virt$get_process_name(arg1, arg2);
case SC_dbgputstr:
return virt$dbgputstr(arg1, arg2);
case SC_dbgputch:
return virt$dbgputch(arg1);
case SC_chmod:
return virt$chmod(arg1, arg2, arg3);
case SC_fchmod:
return virt$fchmod(arg1, arg2);
case SC_fchown:
return virt$fchown(arg1, arg2, arg3);
case SC_accept:
return virt$accept(arg1, arg2, arg3);
case SC_setsockopt:
return virt$setsockopt(arg1);
case SC_bind:
return virt$bind(arg1, arg2, arg3);
case SC_connect:
return virt$connect(arg1, arg2, arg3);
case SC_listen:
return virt$listen(arg1, arg2);
case SC_select:
return virt$select(arg1);
case SC_recvmsg:
return virt$recvmsg(arg1, arg2, arg3);
case SC_sendmsg:
return virt$sendmsg(arg1, arg2, arg3);
case SC_kill:
return virt$kill(arg1, arg2);
case SC_set_mmap_name:
return virt$set_mmap_name(arg1);
case SC_exit:
virt$exit((int)arg1);
return 0;
case SC_gettimeofday:
return virt$gettimeofday(arg1);
case SC_clock_gettime:
return virt$clock_gettime(arg1, arg2);
case SC_clock_settime:
return virt$clock_settime(arg1, arg2);
case SC_getrandom:
return virt$getrandom(arg1, arg2, arg3);
case SC_fork:
return virt$fork();
case SC_sched_getparam:
return virt$sched_getparam(arg1, arg2);
case SC_sched_setparam:
return virt$sched_setparam(arg1, arg2);
case SC_set_thread_name:
return virt$set_thread_name(arg1, arg2, arg3);
case SC_setsid:
return virt$setsid();
case SC_watch_file:
return virt$watch_file(arg1, arg2);
case SC_clock_nanosleep:
return virt$clock_nanosleep(arg1);
case SC_readlink:
return virt$readlink(arg1);
case SC_ptsname:
return virt$ptsname(arg1, arg2, arg3);
case SC_allocate_tls:
return virt$allocate_tls(arg1);
case SC_beep:
return virt$beep();
case SC_ftruncate:
return virt$ftruncate(arg1, arg2);
case SC_umask:
return virt$umask(arg1);
case SC_chown:
return virt$chown(arg1);
case SC_msyscall:
return virt$msyscall(arg1);
default:
reportln("\n=={}== \033[31;1mUnimplemented syscall: {}\033[0m, {:p}", getpid(), Syscall::to_string((Syscall::Function)function), function);
dump_backtrace();
TODO();
}
}
int Emulator::virt$anon_create(size_t size, int options)
{
return syscall(SC_anon_create, size, options);
}
int Emulator::virt$sendfd(int socket, int fd)
{
return syscall(SC_sendfd, socket, fd);
}
int Emulator::virt$recvfd(int socket)
{
return syscall(SC_recvfd, socket);
}
int Emulator::virt$profiling_enable(pid_t pid)
{
return syscall(SC_profiling_enable, pid);
}
int Emulator::virt$profiling_disable(pid_t pid)
{
return syscall(SC_profiling_disable, pid);
}
int Emulator::virt$disown(pid_t pid)
{
return syscall(SC_disown, pid);
}
int Emulator::virt$purge(int mode)
{
return syscall(SC_purge, mode);
}
int Emulator::virt$fstat(int fd, FlatPtr statbuf)
{
struct stat local_statbuf;
int rc = syscall(SC_fstat, fd, &local_statbuf);
if (rc < 0)
return rc;
mmu().copy_to_vm(statbuf, &local_statbuf, sizeof(local_statbuf));
return rc;
}
int Emulator::virt$close(int fd)
{
return syscall(SC_close, fd);
}
int Emulator::virt$mkdir(FlatPtr path, size_t path_length, mode_t mode)
{
auto buffer = mmu().copy_buffer_from_vm(path, path_length);
return syscall(SC_mkdir, buffer.data(), buffer.size(), mode);
}
int Emulator::virt$unlink(FlatPtr path, size_t path_length)
{
auto buffer = mmu().copy_buffer_from_vm(path, path_length);
return syscall(SC_unlink, buffer.data(), buffer.size());
}
int Emulator::virt$dbgputstr(FlatPtr characters, int length)
{
auto buffer = mmu().copy_buffer_from_vm(characters, length);
dbgputstr((const char*)buffer.data(), buffer.size());
return 0;
}
int Emulator::virt$chmod(FlatPtr path_addr, size_t path_length, mode_t mode)
{
auto path = mmu().copy_buffer_from_vm(path_addr, path_length);
return syscall(SC_chmod, path.data(), path.size(), mode);
}
int Emulator::virt$chown(FlatPtr params_addr)
{
Syscall::SC_chown_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
auto path = mmu().copy_buffer_from_vm((FlatPtr)params.path.characters, params.path.length);
params.path.characters = (const char*)path.data();
params.path.length = path.size();
return syscall(SC_chown, &params);
}
int Emulator::virt$fchmod(int fd, mode_t mode)
{
return syscall(SC_fchmod, fd, mode);
}
int Emulator::virt$fchown(int fd, uid_t uid, gid_t gid)
{
return syscall(SC_fchown, fd, uid, gid);
}
int Emulator::virt$setsockopt(FlatPtr params_addr)
{
Syscall::SC_setsockopt_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
if (params.option == SO_RCVTIMEO || params.option == SO_TIMESTAMP) {
auto host_value_buffer = ByteBuffer::create_zeroed(params.value_size);
mmu().copy_from_vm(host_value_buffer.data(), (FlatPtr)params.value, params.value_size);
int rc = setsockopt(params.sockfd, params.level, params.option, host_value_buffer.data(), host_value_buffer.size());
if (rc < 0)
return -errno;
return rc;
}
if (params.option == SO_BINDTODEVICE) {
auto ifname = mmu().copy_buffer_from_vm((FlatPtr)params.value, params.value_size);
params.value = ifname.data();
params.value_size = ifname.size();
return syscall(SC_setsockopt, &params);
}
TODO();
}
int Emulator::virt$get_stack_bounds(FlatPtr base, FlatPtr size)
{
auto* region = mmu().find_region({ m_cpu.ss(), m_cpu.esp().value() });
FlatPtr b = region->base();
size_t s = region->size();
mmu().copy_to_vm(base, &b, sizeof(b));
mmu().copy_to_vm(size, &s, sizeof(s));
return 0;
}
int Emulator::virt$ftruncate(int fd, off_t length)
{
return syscall(SC_ftruncate, fd, length);
}
mode_t Emulator::virt$umask(mode_t mask)
{
return syscall(SC_umask, mask);
}
int Emulator::virt$accept(int sockfd, FlatPtr address, FlatPtr address_length)
{
socklen_t host_address_length = 0;
mmu().copy_from_vm(&host_address_length, address_length, sizeof(host_address_length));
auto host_buffer = ByteBuffer::create_zeroed(host_address_length);
int rc = syscall(SC_accept, sockfd, host_buffer.data(), &host_address_length);
if (rc < 0)
return rc;
mmu().copy_to_vm(address, host_buffer.data(), min((socklen_t)host_buffer.size(), host_address_length));
mmu().copy_to_vm(address_length, &host_address_length, sizeof(host_address_length));
return rc;
}
int Emulator::virt$bind(int sockfd, FlatPtr address, socklen_t address_length)
{
auto buffer = mmu().copy_buffer_from_vm(address, address_length);
return syscall(SC_bind, sockfd, buffer.data(), buffer.size());
}
int Emulator::virt$connect(int sockfd, FlatPtr address, socklen_t address_size)
{
auto buffer = mmu().copy_buffer_from_vm(address, address_size);
return syscall(SC_connect, sockfd, buffer.data(), buffer.size());
}
int Emulator::virt$dbgputch(char ch)
{
dbgputch(ch);
return 0;
}
int Emulator::virt$listen(int fd, int backlog)
{
return syscall(SC_listen, fd, backlog);
}
int Emulator::virt$kill(pid_t pid, int signal)
{
return syscall(SC_kill, pid, signal);
}
int Emulator::virt$gettimeofday(FlatPtr timeval)
{
struct timeval host_timeval;
int rc = syscall(SC_gettimeofday, &host_timeval);
if (rc < 0)
return rc;
mmu().copy_to_vm(timeval, &host_timeval, sizeof(host_timeval));
return rc;
}
int Emulator::virt$clock_gettime(int clockid, FlatPtr timespec)
{
struct timespec host_timespec;
int rc = syscall(SC_clock_gettime, clockid, &host_timespec);
if (rc < 0)
return rc;
mmu().copy_to_vm(timespec, &host_timespec, sizeof(host_timespec));
return rc;
}
int Emulator::virt$clock_settime(uint32_t clock_id, FlatPtr user_ts)
{
struct timespec user_timespec;
mmu().copy_from_vm(&user_timespec, user_ts, sizeof(user_timespec));
int rc = syscall(SC_clock_settime, clock_id, &user_timespec);
return rc;
}
int Emulator::virt$set_mmap_name(FlatPtr)
{
// FIXME: Implement.
return 0;
}
int Emulator::virt$get_process_name(FlatPtr buffer, int size)
{
if (size < 0)
return -EINVAL;
auto host_buffer = ByteBuffer::create_zeroed((size_t)size);
int rc = syscall(SC_get_process_name, host_buffer.data(), host_buffer.size());
mmu().copy_to_vm(buffer, host_buffer.data(), host_buffer.size());
return rc;
}
int Emulator::virt$lseek(int fd, off_t offset, int whence)
{
return syscall(SC_lseek, fd, offset, whence);
}
int Emulator::virt$socket(int domain, int type, int protocol)
{
return syscall(SC_socket, domain, type, protocol);
}
int Emulator::virt$recvmsg(int sockfd, FlatPtr msg_addr, int flags)
{
msghdr mmu_msg;
mmu().copy_from_vm(&mmu_msg, msg_addr, sizeof(mmu_msg));
Vector<iovec, 1> mmu_iovs;
mmu_iovs.resize(mmu_msg.msg_iovlen);
mmu().copy_from_vm(mmu_iovs.data(), (FlatPtr)mmu_msg.msg_iov, mmu_msg.msg_iovlen * sizeof(iovec));
Vector<ByteBuffer, 1> buffers;
Vector<iovec, 1> iovs;
for (const auto& iov : mmu_iovs) {
buffers.append(ByteBuffer::create_uninitialized(iov.iov_len));
iovs.append({ buffers.last().data(), buffers.last().size() });
}
ByteBuffer control_buffer;
if (mmu_msg.msg_control)
control_buffer = ByteBuffer::create_uninitialized(mmu_msg.msg_controllen);
sockaddr_storage addr;
msghdr msg = { &addr, sizeof(addr), iovs.data(), (int)iovs.size(), mmu_msg.msg_control ? control_buffer.data() : nullptr, mmu_msg.msg_controllen, mmu_msg.msg_flags };
int rc = recvmsg(sockfd, &msg, flags);
if (rc < 0)
return -errno;
for (size_t i = 0; i < buffers.size(); ++i)
mmu().copy_to_vm((FlatPtr)mmu_iovs[i].iov_base, buffers[i].data(), mmu_iovs[i].iov_len);
if (mmu_msg.msg_name)
mmu().copy_to_vm((FlatPtr)mmu_msg.msg_name, &addr, min(sizeof(addr), (size_t)mmu_msg.msg_namelen));
if (mmu_msg.msg_control)
mmu().copy_to_vm((FlatPtr)mmu_msg.msg_control, control_buffer.data(), min(mmu_msg.msg_controllen, msg.msg_controllen));
mmu_msg.msg_namelen = msg.msg_namelen;
mmu_msg.msg_controllen = msg.msg_controllen;
mmu_msg.msg_flags = msg.msg_flags;
mmu().copy_to_vm(msg_addr, &mmu_msg, sizeof(mmu_msg));
return rc;
}
int Emulator::virt$sendmsg(int sockfd, FlatPtr msg_addr, int flags)
{
msghdr mmu_msg;
mmu().copy_from_vm(&mmu_msg, msg_addr, sizeof(mmu_msg));
Vector<iovec, 1> iovs;
iovs.resize(mmu_msg.msg_iovlen);
mmu().copy_from_vm(iovs.data(), (FlatPtr)mmu_msg.msg_iov, mmu_msg.msg_iovlen * sizeof(iovec));
Vector<ByteBuffer, 1> buffers;
for (auto& iov : iovs) {
buffers.append(mmu().copy_buffer_from_vm((FlatPtr)iov.iov_base, iov.iov_len));
iov = { buffers.last().data(), buffers.last().size() };
}
ByteBuffer control_buffer;
if (mmu_msg.msg_control)
control_buffer = ByteBuffer::create_uninitialized(mmu_msg.msg_controllen);
sockaddr_storage address;
socklen_t address_length = 0;
if (mmu_msg.msg_name) {
address_length = min(sizeof(address), (size_t)mmu_msg.msg_namelen);
mmu().copy_from_vm(&address, (FlatPtr)mmu_msg.msg_name, address_length);
}
msghdr msg = { mmu_msg.msg_name ? &address : nullptr, address_length, iovs.data(), (int)iovs.size(), mmu_msg.msg_control ? control_buffer.data() : nullptr, mmu_msg.msg_controllen, mmu_msg.msg_flags };
return sendmsg(sockfd, &msg, flags);
}
int Emulator::virt$select(FlatPtr params_addr)
{
Syscall::SC_select_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
fd_set readfds {};
fd_set writefds {};
fd_set exceptfds {};
struct timespec timeout;
u32 sigmask;
if (params.readfds)
mmu().copy_from_vm(&readfds, (FlatPtr)params.readfds, sizeof(readfds));
if (params.writefds)
mmu().copy_from_vm(&writefds, (FlatPtr)params.writefds, sizeof(writefds));
if (params.exceptfds)
mmu().copy_from_vm(&exceptfds, (FlatPtr)params.exceptfds, sizeof(exceptfds));
if (params.timeout)
mmu().copy_from_vm(&timeout, (FlatPtr)params.timeout, sizeof(timeout));
if (params.sigmask)
mmu().copy_from_vm(&sigmask, (FlatPtr)params.sigmask, sizeof(sigmask));
int rc = pselect(params.nfds, &readfds, &writefds, &exceptfds, params.timeout ? &timeout : nullptr, params.sigmask ? &sigmask : nullptr);
if (rc < 0)
return -errno;
if (params.readfds)
mmu().copy_to_vm((FlatPtr)params.readfds, &readfds, sizeof(readfds));
if (params.writefds)
mmu().copy_to_vm((FlatPtr)params.writefds, &writefds, sizeof(writefds));
if (params.exceptfds)
mmu().copy_to_vm((FlatPtr)params.exceptfds, &exceptfds, sizeof(exceptfds));
if (params.timeout)
mmu().copy_to_vm((FlatPtr)params.timeout, &timeout, sizeof(timeout));
return rc;
}
int Emulator::virt$getsockopt(FlatPtr params_addr)
{
Syscall::SC_getsockopt_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
if (params.option == SO_PEERCRED) {
struct ucred creds = {};
socklen_t creds_size = sizeof(creds);
int rc = getsockopt(params.sockfd, params.level, SO_PEERCRED, &creds, &creds_size);
if (rc < 0)
return -errno;
// FIXME: Check params.value_size
mmu().copy_to_vm((FlatPtr)params.value, &creds, sizeof(creds));
return rc;
}
TODO();
}
int Emulator::virt$getgroups(ssize_t count, FlatPtr groups)
{
if (!count)
return syscall(SC_getgroups, 0, nullptr);
auto buffer = ByteBuffer::create_uninitialized(count * sizeof(gid_t));
int rc = syscall(SC_getgroups, count, buffer.data());
if (rc < 0)
return rc;
mmu().copy_to_vm(groups, buffer.data(), buffer.size());
return 0;
}
int Emulator::virt$setgroups(ssize_t count, FlatPtr groups)
{
if (!count)
return syscall(SC_setgroups, 0, nullptr);
auto buffer = mmu().copy_buffer_from_vm(groups, count * sizeof(gid_t));
return syscall(SC_setgroups, count, buffer.data());
}
u32 Emulator::virt$fcntl(int fd, int cmd, u32 arg)
{
switch (cmd) {
case F_DUPFD:
case F_GETFD:
case F_SETFD:
case F_GETFL:
case F_SETFL:
case F_ISTTY:
break;
default:
TODO();
}
return syscall(SC_fcntl, fd, cmd, arg);
}
u32 Emulator::virt$open(u32 params_addr)
{
Syscall::SC_open_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
auto path = mmu().copy_buffer_from_vm((FlatPtr)params.path.characters, params.path.length);
Syscall::SC_open_params host_params {};
host_params.dirfd = params.dirfd;
host_params.mode = params.mode;
host_params.options = params.options;
host_params.path.characters = (const char*)path.data();
host_params.path.length = path.size();
return syscall(SC_open, &host_params);
}
int Emulator::virt$pipe(FlatPtr vm_pipefd, int flags)
{
int pipefd[2];
int rc = syscall(SC_pipe, pipefd, flags);
if (rc < 0)
return rc;
mmu().copy_to_vm(vm_pipefd, pipefd, sizeof(pipefd));
return rc;
}
u32 Emulator::virt$munmap(FlatPtr address, u32 size)
{
auto* region = mmu().find_region({ 0x23, address });
ASSERT(region);
if (region->size() != round_up_to_power_of_two(size, PAGE_SIZE))
TODO();
m_range_allocator.deallocate(region->range());
mmu().remove_region(*region);
return 0;
}
u32 Emulator::virt$mmap(u32 params_addr)
{
Syscall::SC_mmap_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
u32 requested_size = round_up_to_power_of_two(params.size, PAGE_SIZE);
FlatPtr final_address;
Optional<Range> result;
if (params.flags & MAP_RANDOMIZED) {
result = m_range_allocator.allocate_randomized(requested_size, params.alignment);
} else if (params.flags & MAP_FIXED) {
result = m_range_allocator.allocate_specific(VirtualAddress { params.addr }, requested_size);
} else {
result = m_range_allocator.allocate_anywhere(requested_size, params.alignment);
}
if (!result.has_value())
return -ENOMEM;
final_address = result.value().base().get();
auto final_size = result.value().size();
if (params.flags & MAP_ANONYMOUS)
mmu().add_region(MmapRegion::create_anonymous(final_address, final_size, params.prot));
else {
String name_str;
if (params.name.characters) {
auto name = ByteBuffer::create_uninitialized(params.name.length);
mmu().copy_from_vm(name.data(), (FlatPtr)params.name.characters, params.name.length);
name_str = { name.data(), name.size() };
}
auto region = MmapRegion::create_file_backed(final_address, final_size, params.prot, params.flags, params.fd, params.offset, name_str);
if (region->name() == "libc.so: .text (Emulated)") {
bool rc = find_malloc_symbols(*region);
ASSERT(rc);
}
mmu().add_region(move(region));
}
return final_address;
}
FlatPtr Emulator::virt$mremap(FlatPtr params_addr)
{
Syscall::SC_mremap_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
if (auto* region = mmu().find_region({ m_cpu.ds(), params.old_address })) {
if (!is<MmapRegion>(*region))
return -EINVAL;
ASSERT(region->size() == params.old_size);
auto& mmap_region = *(MmapRegion*)region;
auto* ptr = mremap(mmap_region.data(), mmap_region.size(), mmap_region.size(), params.flags);
if (ptr == MAP_FAILED)
return -errno;
return (FlatPtr)ptr;
}
return -EINVAL;
}
u32 Emulator::virt$mount(u32 params_addr)
{
Syscall::SC_mount_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
auto target = mmu().copy_buffer_from_vm((FlatPtr)params.target.characters, params.target.length);
auto fs_path = mmu().copy_buffer_from_vm((FlatPtr)params.fs_type.characters, params.fs_type.length);
params.fs_type.characters = (char*)fs_path.data();
params.fs_type.length = fs_path.size();
params.target.characters = (char*)target.data();
params.target.length = target.size();
return syscall(SC_mount, &params);
}
u32 Emulator::virt$gettid()
{
return gettid();
}
u32 Emulator::virt$getpid()
{
return getpid();
}
u32 Emulator::virt$pledge(u32)
{
return 0;
}
u32 Emulator::virt$unveil(u32)
{
return 0;
}
u32 Emulator::virt$mprotect(FlatPtr base, size_t size, int prot)
{
if (auto* region = mmu().find_region({ m_cpu.ds(), base })) {
if (!is<MmapRegion>(*region))
return -EINVAL;
ASSERT(region->size() == size);
auto& mmap_region = *(MmapRegion*)region;
mmap_region.set_prot(prot);
return 0;
}
return -EINVAL;
}
u32 Emulator::virt$madvise(FlatPtr, size_t, int)
{
return 0;
}
uid_t Emulator::virt$getuid()
{
return getuid();
}
uid_t Emulator::virt$geteuid()
{
return geteuid();
}
gid_t Emulator::virt$getgid()
{
return getgid();
}
gid_t Emulator::virt$getegid()
{
return getegid();
}
int Emulator::virt$setuid(uid_t uid)
{
return syscall(SC_setuid, uid);
}
int Emulator::virt$setgid(gid_t gid)
{
return syscall(SC_setgid, gid);
}
u32 Emulator::virt$write(int fd, FlatPtr data, ssize_t size)
{
if (size < 0)
return -EINVAL;
auto buffer = mmu().copy_buffer_from_vm(data, size);
return syscall(SC_write, fd, buffer.data(), buffer.size());
}
u32 Emulator::virt$read(int fd, FlatPtr buffer, ssize_t size)
{
if (size < 0)
return -EINVAL;
auto local_buffer = ByteBuffer::create_uninitialized(size);
int nread = syscall(SC_read, fd, local_buffer.data(), local_buffer.size());
if (nread < 0) {
if (nread == -EPERM) {
dump_backtrace();
TODO();
}
return nread;
}
mmu().copy_to_vm(buffer, local_buffer.data(), local_buffer.size());
return nread;
}
void Emulator::virt$exit(int status)
{
reportln("\n=={}== \033[33;1mSyscall: exit({})\033[0m, shutting down!", getpid(), status);
m_exit_status = status;
m_shutdown = true;
}
ssize_t Emulator::virt$getrandom(FlatPtr buffer, size_t buffer_size, unsigned int flags)
{
auto host_buffer = ByteBuffer::create_uninitialized(buffer_size);
int rc = syscall(SC_getrandom, host_buffer.data(), host_buffer.size(), flags);
if (rc < 0)
return rc;
mmu().copy_to_vm(buffer, host_buffer.data(), host_buffer.size());
return rc;
}
int Emulator::virt$get_dir_entries(int fd, FlatPtr buffer, ssize_t size)
{
auto host_buffer = ByteBuffer::create_uninitialized(size);
int rc = syscall(SC_get_dir_entries, fd, host_buffer.data(), host_buffer.size());
if (rc < 0)
return rc;
mmu().copy_to_vm(buffer, host_buffer.data(), host_buffer.size());
return rc;
}
int Emulator::virt$ioctl([[maybe_unused]] int fd, unsigned request, [[maybe_unused]] FlatPtr arg)
{
if (request == TIOCGWINSZ) {
struct winsize ws;
int rc = syscall(SC_ioctl, fd, TIOCGWINSZ, &ws);
if (rc < 0)
return rc;
mmu().copy_to_vm(arg, &ws, sizeof(winsize));
return 0;
}
if (request == TIOCSPGRP) {
return syscall(SC_ioctl, fd, request, arg);
}
if (request == TCGETS) {
struct termios termios;
int rc = syscall(SC_ioctl, fd, request, &termios);
if (rc < 0)
return rc;
mmu().copy_to_vm(arg, &termios, sizeof(termios));
return rc;
}
if (request == TCSETS) {
struct termios termios;
mmu().copy_from_vm(&termios, arg, sizeof(termios));
return syscall(SC_ioctl, fd, request, &termios);
}
if (request == TIOCNOTTY || request == TIOCSCTTY) {
return syscall(SC_ioctl, fd, request, 0);
}
if (request == FB_IOCTL_GET_SIZE_IN_BYTES) {
size_t size = 0;
auto rc = syscall(SC_ioctl, fd, request, &size);
mmu().copy_to_vm(arg, &size, sizeof(size));
return rc;
}
if (request == FB_IOCTL_SET_RESOLUTION) {
FBResolution user_resolution;
mmu().copy_from_vm(&user_resolution, arg, sizeof(user_resolution));
auto rc = syscall(SC_ioctl, fd, request, &user_resolution);
mmu().copy_to_vm(arg, &user_resolution, sizeof(user_resolution));
return rc;
}
if (request == FB_IOCTL_SET_BUFFER) {
return syscall(SC_ioctl, fd, request, arg);
}
reportln("Unsupported ioctl: {}", request);
dump_backtrace();
TODO();
}
int Emulator::virt$fork()
{
int rc = fork();
if (rc < 0)
return -errno;
return rc;
}
int Emulator::virt$execve(FlatPtr params_addr)
{
Syscall::SC_execve_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
auto path = String::copy(mmu().copy_buffer_from_vm((FlatPtr)params.path.characters, params.path.length));
Vector<String> arguments;
Vector<String> environment;
auto copy_string_list = [this](auto& output_vector, auto& string_list) {
for (size_t i = 0; i < string_list.length; ++i) {
Syscall::StringArgument string;
mmu().copy_from_vm(&string, (FlatPtr)&string_list.strings[i], sizeof(string));
output_vector.append(String::copy(mmu().copy_buffer_from_vm((FlatPtr)string.characters, string.length)));
}
};
copy_string_list(arguments, params.arguments);
copy_string_list(environment, params.environment);
reportln("\n=={}== \033[33;1mSyscall:\033[0m execve", getpid());
reportln("=={}== @ {}", getpid(), path);
for (auto& argument : arguments)
reportln("=={}== - {}", getpid(), argument);
Vector<char*> argv;
Vector<char*> envp;
argv.append(const_cast<char*>("/bin/UserspaceEmulator"));
argv.append(const_cast<char*>(path.characters()));
if (g_report_to_debug)
argv.append(const_cast<char*>("--report-to-debug"));
argv.append(const_cast<char*>("--"));
auto create_string_vector = [](auto& output_vector, auto& input_vector) {
for (auto& string : input_vector)
output_vector.append(const_cast<char*>(string.characters()));
output_vector.append(nullptr);
};
create_string_vector(argv, arguments);
create_string_vector(envp, environment);
// Yoink duplicated program name.
argv.remove(3 + (g_report_to_debug ? 1 : 0));
return execve(argv[0], (char* const*)argv.data(), (char* const*)envp.data());
}
int Emulator::virt$stat(FlatPtr params_addr)
{
Syscall::SC_stat_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
auto path = String::copy(mmu().copy_buffer_from_vm((FlatPtr)params.path.characters, params.path.length));
struct stat host_statbuf;
int rc;
if (params.follow_symlinks)
rc = stat(path.characters(), &host_statbuf);
else
rc = lstat(path.characters(), &host_statbuf);
if (rc < 0)
return -errno;
mmu().copy_to_vm((FlatPtr)params.statbuf, &host_statbuf, sizeof(host_statbuf));
return rc;
}
int Emulator::virt$realpath(FlatPtr params_addr)
{
Syscall::SC_realpath_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
auto path = mmu().copy_buffer_from_vm((FlatPtr)params.path.characters, params.path.length);
auto host_buffer = ByteBuffer::create_zeroed(params.buffer.size);
Syscall::SC_realpath_params host_params;
host_params.path = { (const char*)path.data(), path.size() };
host_params.buffer = { (char*)host_buffer.data(), host_buffer.size() };
int rc = syscall(SC_realpath, &host_params);
if (rc < 0)
return rc;
mmu().copy_to_vm((FlatPtr)params.buffer.data, host_buffer.data(), host_buffer.size());
return rc;
}
int Emulator::virt$gethostname(FlatPtr buffer, ssize_t buffer_size)
{
if (buffer_size < 0)
return -EINVAL;
auto host_buffer = ByteBuffer::create_zeroed(buffer_size);
int rc = syscall(SC_gethostname, host_buffer.data(), host_buffer.size());
if (rc < 0)
return rc;
mmu().copy_to_vm(buffer, host_buffer.data(), host_buffer.size());
return rc;
}
static void emulator_signal_handler(int signum)
{
Emulator::the().did_receive_signal(signum);
}
void Emulator::register_signal_handlers()
{
for (int signum = 0; signum < NSIG; ++signum)
signal(signum, emulator_signal_handler);
}
int Emulator::virt$sigaction(int signum, FlatPtr act, FlatPtr oldact)
{
if (signum == SIGKILL) {
reportln("Attempted to sigaction() with SIGKILL");
return -EINVAL;
}
if (signum <= 0 || signum >= NSIG)
return -EINVAL;
struct sigaction host_act;
mmu().copy_from_vm(&host_act, act, sizeof(host_act));
auto& handler = m_signal_handler[signum];
handler.handler = (FlatPtr)host_act.sa_handler;
handler.mask = host_act.sa_mask;
handler.flags = host_act.sa_flags;
if (oldact) {
struct sigaction host_oldact;
auto& old_handler = m_signal_handler[signum];
host_oldact.sa_handler = (void (*)(int))(old_handler.handler);
host_oldact.sa_mask = old_handler.mask;
host_oldact.sa_flags = old_handler.flags;
mmu().copy_to_vm(oldact, &host_oldact, sizeof(host_oldact));
}
return 0;
}
int Emulator::virt$sigreturn()
{
u32 stack_ptr = m_cpu.esp().value();
auto local_pop = [&]() -> ValueWithShadow<u32> {
auto value = m_cpu.read_memory32({ m_cpu.ss(), stack_ptr });
stack_ptr += sizeof(u32);
return value;
};
auto smuggled_eax = local_pop();
stack_ptr += 4 * sizeof(u32);
m_signal_mask = local_pop().value();
m_cpu.set_edi(local_pop());
m_cpu.set_esi(local_pop());
m_cpu.set_ebp(local_pop());
m_cpu.set_esp(local_pop());
m_cpu.set_ebx(local_pop());
m_cpu.set_edx(local_pop());
m_cpu.set_ecx(local_pop());
m_cpu.set_eax(local_pop());
m_cpu.set_eip(local_pop().value());
m_cpu.set_eflags(local_pop());
// FIXME: We're losing shadow bits here.
return smuggled_eax.value();
}
enum class DefaultSignalAction {
Terminate,
Ignore,
DumpCore,
Stop,
Continue,
};
static DefaultSignalAction default_signal_action(int signal)
{
ASSERT(signal && signal < NSIG);
switch (signal) {
case SIGHUP:
case SIGINT:
case SIGKILL:
case SIGPIPE:
case SIGALRM:
case SIGUSR1:
case SIGUSR2:
case SIGVTALRM:
case SIGSTKFLT:
case SIGIO:
case SIGPROF:
case SIGTERM:
return DefaultSignalAction::Terminate;
case SIGCHLD:
case SIGURG:
case SIGWINCH:
case SIGINFO:
return DefaultSignalAction::Ignore;
case SIGQUIT:
case SIGILL:
case SIGTRAP:
case SIGABRT:
case SIGBUS:
case SIGFPE:
case SIGSEGV:
case SIGXCPU:
case SIGXFSZ:
case SIGSYS:
return DefaultSignalAction::DumpCore;
case SIGCONT:
return DefaultSignalAction::Continue;
case SIGSTOP:
case SIGTSTP:
case SIGTTIN:
case SIGTTOU:
return DefaultSignalAction::Stop;
}
ASSERT_NOT_REACHED();
}
void Emulator::dispatch_one_pending_signal()
{
int signum = -1;
for (signum = 1; signum < NSIG; ++signum) {
int mask = 1 << signum;
if (m_pending_signals & mask)
break;
}
ASSERT(signum != -1);
m_pending_signals &= ~(1 << signum);
auto& handler = m_signal_handler[signum];
if (handler.handler == 0) {
// SIG_DFL
auto action = default_signal_action(signum);
if (action == DefaultSignalAction::Ignore)
return;
reportln("\n=={}== Got signal {} ({}), no handler registered", getpid(), signum, strsignal(signum));
m_shutdown = true;
return;
}
if (handler.handler == 1) {
// SIG_IGN
return;
}
reportln("\n=={}== Got signal {} ({}), handler at {:p}", getpid(), signum, strsignal(signum), handler.handler);
auto old_esp = m_cpu.esp();
u32 stack_alignment = (m_cpu.esp().value() - 56) % 16;
m_cpu.set_esp(shadow_wrap_as_initialized(m_cpu.esp().value() - stack_alignment));
m_cpu.push32(shadow_wrap_as_initialized(m_cpu.eflags()));
m_cpu.push32(shadow_wrap_as_initialized(m_cpu.eip()));
m_cpu.push32(m_cpu.eax());
m_cpu.push32(m_cpu.ecx());
m_cpu.push32(m_cpu.edx());
m_cpu.push32(m_cpu.ebx());
m_cpu.push32(old_esp);
m_cpu.push32(m_cpu.ebp());
m_cpu.push32(m_cpu.esi());
m_cpu.push32(m_cpu.edi());
// FIXME: Push old signal mask here.
m_cpu.push32(shadow_wrap_as_initialized(0u));
m_cpu.push32(shadow_wrap_as_initialized((u32)signum));
m_cpu.push32(shadow_wrap_as_initialized(handler.handler));
m_cpu.push32(shadow_wrap_as_initialized(0u));
ASSERT((m_cpu.esp().value() % 16) == 0);
m_cpu.set_eip(m_signal_trampoline);
}
// Make sure the compiler doesn't "optimize away" this function:
extern void signal_trampoline_dummy();
void signal_trampoline_dummy()
{
// The trampoline preserves the current eax, pushes the signal code and
// then calls the signal handler. We do this because, when interrupting a
// blocking syscall, that syscall may return some special error code in eax;
// This error code would likely be overwritten by the signal handler, so it's
// necessary to preserve it here.
asm(
".intel_syntax noprefix\n"
"asm_signal_trampoline:\n"
"push ebp\n"
"mov ebp, esp\n"
"push eax\n" // we have to store eax 'cause it might be the return value from a syscall
"sub esp, 4\n" // align the stack to 16 bytes
"mov eax, [ebp+12]\n" // push the signal code
"push eax\n"
"call [ebp+8]\n" // call the signal handler
"add esp, 8\n"
"mov eax, %P0\n"
"int 0x82\n" // sigreturn syscall
"asm_signal_trampoline_end:\n"
".att_syntax" ::"i"(Syscall::SC_sigreturn));
}
extern "C" void asm_signal_trampoline(void);
extern "C" void asm_signal_trampoline_end(void);
void Emulator::setup_signal_trampoline()
{
auto trampoline_region = make<SimpleRegion>(0xb0000000, 4096);
u8* trampoline = (u8*)asm_signal_trampoline;
u8* trampoline_end = (u8*)asm_signal_trampoline_end;
size_t trampoline_size = trampoline_end - trampoline;
u8* code_ptr = trampoline_region->data();
memcpy(code_ptr, trampoline, trampoline_size);
m_signal_trampoline = trampoline_region->base();
mmu().add_region(move(trampoline_region));
}
int Emulator::virt$getpgrp()
{
return syscall(SC_getpgrp);
}
int Emulator::virt$getpgid(pid_t pid)
{
return syscall(SC_getpgid, pid);
}
int Emulator::virt$setpgid(pid_t pid, pid_t pgid)
{
return syscall(SC_setpgid, pid, pgid);
}
int Emulator::virt$ttyname(int fd, FlatPtr buffer, size_t buffer_size)
{
auto host_buffer = ByteBuffer::create_zeroed(buffer_size);
int rc = syscall(SC_ttyname, fd, host_buffer.data(), host_buffer.size());
if (rc < 0)
return rc;
mmu().copy_to_vm(buffer, host_buffer.data(), host_buffer.size());
return rc;
}
int Emulator::virt$getcwd(FlatPtr buffer, size_t buffer_size)
{
auto host_buffer = ByteBuffer::create_zeroed(buffer_size);
int rc = syscall(SC_getcwd, host_buffer.data(), host_buffer.size());
if (rc < 0)
return rc;
mmu().copy_to_vm(buffer, host_buffer.data(), host_buffer.size());
return rc;
}
int Emulator::virt$getsid(pid_t pid)
{
return syscall(SC_getsid, pid);
}
int Emulator::virt$access(FlatPtr path, size_t path_length, int type)
{
auto host_path = mmu().copy_buffer_from_vm(path, path_length);
return syscall(SC_access, host_path.data(), host_path.size(), type);
}
int Emulator::virt$waitid(FlatPtr params_addr)
{
Syscall::SC_waitid_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
Syscall::SC_waitid_params host_params = params;
siginfo info;
host_params.infop = &info;
int rc = syscall(SC_waitid, &host_params);
if (rc < 0)
return rc;
if (info.si_addr) {
// FIXME: Translate this somehow.
TODO();
}
if (params.infop)
mmu().copy_to_vm((FlatPtr)params.infop, &info, sizeof(info));
return rc;
}
int Emulator::virt$chdir(FlatPtr path, size_t path_length)
{
auto host_path = mmu().copy_buffer_from_vm(path, path_length);
return syscall(SC_chdir, host_path.data(), host_path.size());
}
int Emulator::virt$dup2(int old_fd, int new_fd)
{
return syscall(SC_dup2, old_fd, new_fd);
}
int Emulator::virt$sched_getparam(pid_t pid, FlatPtr user_addr)
{
sched_param user_param;
mmu().copy_from_vm(&user_param, user_addr, sizeof(user_param));
auto rc = syscall(SC_sched_getparam, pid, &user_param);
mmu().copy_to_vm(user_addr, &user_param, sizeof(user_param));
return rc;
}
int Emulator::virt$sched_setparam(int pid, FlatPtr user_addr)
{
sched_param user_param;
mmu().copy_from_vm(&user_param, user_addr, sizeof(user_param));
return syscall(SC_sched_setparam, pid, &user_param);
}
int Emulator::virt$set_thread_name(pid_t pid, FlatPtr name_addr, size_t name_length)
{
auto user_name = mmu().copy_buffer_from_vm(name_addr, name_length);
auto name = String::formatted("(UE) {}", StringView { user_name.data(), user_name.size() });
return syscall(SC_set_thread_name, pid, name.characters(), name.length());
}
pid_t Emulator::virt$setsid()
{
return syscall(SC_setsid);
}
int Emulator::virt$watch_file(FlatPtr user_path_addr, size_t path_length)
{
auto user_path = mmu().copy_buffer_from_vm(user_path_addr, path_length);
return syscall(SC_watch_file, user_path.data(), user_path.size());
}
int Emulator::virt$clock_nanosleep(FlatPtr params_addr)
{
Syscall::SC_clock_nanosleep_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
timespec requested_sleep;
mmu().copy_from_vm(&requested_sleep, (FlatPtr)params.requested_sleep, sizeof(timespec));
params.requested_sleep = &requested_sleep;
auto remaining_vm_addr = params.remaining_sleep;
auto remaining = ByteBuffer::create_zeroed(sizeof(timespec));
params.remaining_sleep = (timespec*)remaining.data();
int rc = syscall(SC_clock_nanosleep, &params);
if (remaining_vm_addr)
mmu().copy_to_vm((FlatPtr)remaining_vm_addr, remaining.data(), sizeof(timespec));
return rc;
}
int Emulator::virt$readlink(FlatPtr params_addr)
{
Syscall::SC_readlink_params params;
mmu().copy_from_vm(&params, params_addr, sizeof(params));
auto path = mmu().copy_buffer_from_vm((FlatPtr)params.path.characters, params.path.length);
auto host_buffer = ByteBuffer::create_zeroed(params.buffer.size);
Syscall::SC_readlink_params host_params;
host_params.path = { (const char*)path.data(), path.size() };
host_params.buffer = { (char*)host_buffer.data(), host_buffer.size() };
int rc = syscall(SC_readlink, &host_params);
if (rc < 0)
return rc;
mmu().copy_to_vm((FlatPtr)params.buffer.data, host_buffer.data(), host_buffer.size());
return rc;
}
u32 Emulator::virt$allocate_tls(size_t size)
{
// TODO: Why is this needed? without this, the loader overflows the bounds of the TLS region.
constexpr size_t TLS_SIZE_HACK = 8;
auto tcb_region = make<SimpleRegion>(0x20000000, size + TLS_SIZE_HACK);
bzero(tcb_region->data(), size);
memset(tcb_region->shadow_data(), 0x01, size);
auto tls_region = make<SimpleRegion>(0, 4);
tls_region->write32(0, shadow_wrap_as_initialized(tcb_region->base() + (u32)size));
memset(tls_region->shadow_data(), 0x01, 4);
u32 tls_base = tcb_region->base();
mmu().add_region(move(tcb_region));
mmu().set_tls_region(move(tls_region));
return tls_base;
}
int Emulator::virt$ptsname(int fd, FlatPtr buffer, size_t buffer_size)
{
auto pts = mmu().copy_buffer_from_vm(buffer, buffer_size);
return syscall(SC_ptsname, fd, pts.data(), pts.size());
}
int Emulator::virt$beep()
{
return syscall(SC_beep);
}
bool Emulator::find_malloc_symbols(const MmapRegion& libc_text)
{
auto file_or_error = MappedFile::map("/usr/lib/libc.so");
if (file_or_error.is_error())
return false;
ELF::Image image(file_or_error.value()->bytes());
auto malloc_symbol = image.find_demangled_function("malloc");
auto free_symbol = image.find_demangled_function("free");
auto realloc_symbol = image.find_demangled_function("realloc");
auto malloc_size_symbol = image.find_demangled_function("malloc_size");
if (!malloc_symbol.has_value() || !free_symbol.has_value() || !realloc_symbol.has_value() || !malloc_size_symbol.has_value())
return false;
m_malloc_symbol_start = malloc_symbol.value().value() + libc_text.base();
m_malloc_symbol_end = m_malloc_symbol_start + malloc_symbol.value().size();
m_free_symbol_start = free_symbol.value().value() + libc_text.base();
m_free_symbol_end = m_free_symbol_start + free_symbol.value().size();
m_realloc_symbol_start = realloc_symbol.value().value() + libc_text.base();
m_realloc_symbol_end = m_realloc_symbol_start + realloc_symbol.value().size();
m_malloc_size_symbol_start = malloc_size_symbol.value().value() + libc_text.base();
m_malloc_size_symbol_end = m_malloc_size_symbol_start + malloc_size_symbol.value().size();
return true;
}
int Emulator::virt$msyscall(FlatPtr)
{
// FIXME: Implement this.
return 0;
}
}