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banan-os/kernel/kernel/Process.cpp

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#include <BAN/ScopeGuard.h>
#include <BAN/StringView.h>
#include <kernel/CriticalScope.h>
#include <kernel/FS/DevFS/FileSystem.h>
#include <kernel/FS/ProcFS/FileSystem.h>
#include <kernel/FS/VirtualFileSystem.h>
#include <kernel/IDT.h>
#include <kernel/InterruptController.h>
#include <kernel/LockGuard.h>
#include <kernel/Memory/FileBackedRegion.h>
#include <kernel/Memory/Heap.h>
#include <kernel/Memory/MemoryBackedRegion.h>
#include <kernel/Memory/PageTableScope.h>
#include <kernel/Process.h>
#include <kernel/Scheduler.h>
#include <kernel/Storage/StorageDevice.h>
#include <kernel/Timer/Timer.h>
#include <LibELF/LoadableELF.h>
#include <lai/helpers/pm.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/banan-os.h>
#include <sys/sysmacros.h>
#include <sys/wait.h>
namespace Kernel
{
static BAN::Vector<Process*> s_processes;
static RecursiveSpinLock s_process_lock;
void Process::for_each_process(const BAN::Function<BAN::Iteration(Process&)>& callback)
{
LockGuard _(s_process_lock);
for (auto* process : s_processes)
{
auto ret = callback(*process);
if (ret == BAN::Iteration::Break)
return;
ASSERT(ret == BAN::Iteration::Continue);
}
}
void Process::for_each_process_in_session(pid_t sid, const BAN::Function<BAN::Iteration(Process&)>& callback)
{
LockGuard _(s_process_lock);
for (auto* process : s_processes)
{
if (process->sid() != sid)
continue;
auto ret = callback(*process);
if (ret == BAN::Iteration::Break)
return;
ASSERT(ret == BAN::Iteration::Continue);
}
}
Process* Process::create_process(const Credentials& credentials, pid_t parent, pid_t sid, pid_t pgrp)
{
static pid_t s_next_id = 1;
pid_t pid;
{
CriticalScope _;
pid = s_next_id;
if (sid == 0 && pgrp == 0)
{
sid = s_next_id;
pgrp = s_next_id;
}
s_next_id++;
}
ASSERT(sid > 0);
ASSERT(pgrp > 0);
auto* process = new Process(credentials, pid, parent, sid, pgrp);
ASSERT(process);
MUST(ProcFileSystem::get().on_process_create(*process));
return process;
}
void Process::register_to_scheduler()
{
s_process_lock.lock();
MUST(s_processes.push_back(this));
s_process_lock.unlock();
for (auto* thread : m_threads)
MUST(Scheduler::get().add_thread(thread));
}
Process* Process::create_kernel()
{
auto* process = create_process({ 0, 0, 0, 0 }, 0);
MUST(process->m_working_directory.push_back('/'));
return process;
}
Process* Process::create_kernel(entry_t entry, void* data)
{
auto* process = create_process({ 0, 0, 0, 0 }, 0);
MUST(process->m_working_directory.push_back('/'));
auto* thread = MUST(Thread::create_kernel(entry, data, process));
process->add_thread(thread);
process->register_to_scheduler();
return process;
}
BAN::ErrorOr<Process*> Process::create_userspace(const Credentials& credentials, BAN::StringView path)
{
auto* process = create_process(credentials, 0);
MUST(process->m_working_directory.push_back('/'));
process->m_page_table = BAN::UniqPtr<PageTable>::adopt(MUST(PageTable::create_userspace()));
TRY(process->m_cmdline.push_back({}));
TRY(process->m_cmdline.back().append(path));
process->m_loadable_elf = TRY(load_elf_for_exec(credentials, path, "/"sv, process->page_table()));
if (!process->m_loadable_elf->is_address_space_free())
{
dprintln("Could not load ELF address space");
return BAN::Error::from_errno(ENOEXEC);
}
process->m_loadable_elf->reserve_address_space();
process->m_is_userspace = true;
process->m_userspace_info.entry = process->m_loadable_elf->entry_point();
char** argv = nullptr;
{
PageTableScope _(process->page_table());
size_t needed_bytes = sizeof(char*) * 2 + path.size() + 1;
if (auto rem = needed_bytes % PAGE_SIZE)
needed_bytes += PAGE_SIZE - rem;
auto argv_region = MUST(MemoryBackedRegion::create(
process->page_table(),
needed_bytes,
{ .start = 0x400000, .end = KERNEL_OFFSET },
MemoryRegion::Type::PRIVATE,
PageTable::Flags::UserSupervisor | PageTable::Flags::ReadWrite | PageTable::Flags::Present
));
uintptr_t temp = argv_region->vaddr() + sizeof(char*) * 2;
MUST(argv_region->copy_data_to_region(0, (const uint8_t*)&temp, sizeof(char*)));
temp = 0;
MUST(argv_region->copy_data_to_region(sizeof(char*), (const uint8_t*)&temp, sizeof(char*)));
MUST(argv_region->copy_data_to_region(sizeof(char*) * 2, (const uint8_t*)path.data(), path.size()));
MUST(process->m_mapped_regions.push_back(BAN::move(argv_region)));
}
process->m_userspace_info.argc = 1;
process->m_userspace_info.argv = argv;
process->m_userspace_info.envp = nullptr;
auto* thread = MUST(Thread::create_userspace(process));
process->add_thread(thread);
process->register_to_scheduler();
return process;
}
Process::Process(const Credentials& credentials, pid_t pid, pid_t parent, pid_t sid, pid_t pgrp)
: m_credentials(credentials)
, m_open_file_descriptors(m_credentials)
, m_sid(sid)
, m_pgrp(pgrp)
, m_pid(pid)
, m_parent(parent)
{
for (size_t i = 0; i < sizeof(m_signal_handlers) / sizeof(*m_signal_handlers); i++)
m_signal_handlers[i] = (vaddr_t)SIG_DFL;
}
Process::~Process()
{
ASSERT(m_threads.empty());
ASSERT(m_mapped_regions.empty());
ASSERT(!m_loadable_elf);
ASSERT(m_exit_status.waiting == 0);
ASSERT(&PageTable::current() != m_page_table.ptr());
}
void Process::add_thread(Thread* thread)
{
LockGuard _(m_lock);
MUST(m_threads.push_back(thread));
}
void Process::cleanup_function()
{
s_process_lock.lock();
for (size_t i = 0; i < s_processes.size(); i++)
if (s_processes[i] == this)
s_processes.remove(i);
s_process_lock.unlock();
ProcFileSystem::get().on_process_delete(*this);
m_lock.lock();
m_exit_status.exited = true;
while (m_exit_status.waiting > 0)
{
m_exit_status.semaphore.unblock();
while (m_lock.is_locked())
m_lock.unlock();
Scheduler::get().reschedule();
m_lock.lock();
}
m_open_file_descriptors.close_all();
// NOTE: We must unmap ranges while the page table is still alive
m_mapped_regions.clear();
m_loadable_elf.clear();
}
void Process::on_thread_exit(Thread& thread)
{
ASSERT(!interrupts_enabled());
ASSERT(m_threads.size() > 0);
if (m_threads.size() == 1)
{
ASSERT(m_threads.front() == &thread);
m_threads.clear();
thread.setup_process_cleanup();
Scheduler::get().execute_current_thread();
}
for (size_t i = 0; i < m_threads.size(); i++)
{
if (m_threads[i] == &thread)
{
m_threads.remove(i);
return;
}
}
ASSERT_NOT_REACHED();
}
void Process::exit(int status, int signal)
{
LockGuard _(m_lock);
m_exit_status.exit_code = __WGENEXITCODE(status, signal);
for (auto* thread : m_threads)
thread->set_terminating();
}
size_t Process::proc_meminfo(off_t offset, BAN::ByteSpan buffer) const
{
ASSERT(offset >= 0);
if ((size_t)offset >= sizeof(proc_meminfo_t))
return 0;
proc_meminfo_t meminfo;
meminfo.page_size = PAGE_SIZE;
meminfo.virt_pages = 0;
meminfo.phys_pages = 0;
{
LockGuard _(m_lock);
for (auto* thread : m_threads)
{
meminfo.virt_pages += thread->virtual_page_count();
meminfo.phys_pages += thread->physical_page_count();
}
for (auto& region : m_mapped_regions)
{
meminfo.virt_pages += region->virtual_page_count();
meminfo.phys_pages += region->physical_page_count();
}
if (m_loadable_elf)
{
meminfo.virt_pages += m_loadable_elf->virtual_page_count();
meminfo.phys_pages += m_loadable_elf->physical_page_count();
}
}
size_t bytes = BAN::Math::min<size_t>(sizeof(proc_meminfo_t) - offset, buffer.size());
memcpy(buffer.data(), (uint8_t*)&meminfo + offset, bytes);
return bytes;
}
static size_t read_from_vec_of_str(const BAN::Vector<BAN::String>& container, size_t start, BAN::ByteSpan buffer)
{
size_t offset = 0;
size_t written = 0;
for (const auto& elem : container)
{
if (start < offset + elem.size() + 1)
{
size_t elem_offset = 0;
if (offset < start)
elem_offset = start - offset;
size_t bytes = BAN::Math::min<size_t>(elem.size() + 1 - elem_offset, buffer.size() - written);
memcpy(buffer.data() + written, elem.data() + elem_offset, bytes);
written += bytes;
if (written >= buffer.size())
break;
}
offset += elem.size() + 1;
}
return written;
}
size_t Process::proc_cmdline(off_t offset, BAN::ByteSpan buffer) const
{
LockGuard _(m_lock);
return read_from_vec_of_str(m_cmdline, offset, buffer);
}
size_t Process::proc_environ(off_t offset, BAN::ByteSpan buffer) const
{
LockGuard _(m_lock);
return read_from_vec_of_str(m_environ, offset, buffer);
}
BAN::ErrorOr<long> Process::sys_exit(int status)
{
exit(status, 0);
Thread::TerminateBlocker _(Thread::current());
ASSERT_NOT_REACHED();
}
BAN::ErrorOr<long> Process::sys_gettermios(::termios* termios)
{
LockGuard _(m_lock);
validate_pointer_access(termios, sizeof(::termios));
if (!m_controlling_terminal)
return BAN::Error::from_errno(ENOTTY);
Kernel::termios ktermios = m_controlling_terminal->get_termios();
termios->c_lflag = 0;
if (ktermios.canonical)
termios->c_lflag |= ICANON;
if (ktermios.echo)
termios->c_lflag |= ECHO;
return 0;
}
BAN::ErrorOr<long> Process::sys_settermios(const ::termios* termios)
{
LockGuard _(m_lock);
validate_pointer_access(termios, sizeof(::termios));
if (!m_controlling_terminal)
return BAN::Error::from_errno(ENOTTY);
Kernel::termios ktermios;
ktermios.echo = termios->c_lflag & ECHO;
ktermios.canonical = termios->c_lflag & ICANON;
m_controlling_terminal->set_termios(ktermios);
return 0;
}
BAN::ErrorOr<BAN::UniqPtr<LibELF::LoadableELF>> Process::load_elf_for_exec(const Credentials& credentials, BAN::StringView file_path, const BAN::String& cwd, PageTable& page_table)
{
if (file_path.empty())
return BAN::Error::from_errno(ENOENT);
BAN::String absolute_path;
if (file_path.front() == '/')
TRY(absolute_path.append(file_path));
else
{
TRY(absolute_path.append(cwd));
TRY(absolute_path.push_back('/'));
TRY(absolute_path.append(file_path));
}
auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(credentials, absolute_path, O_EXEC));
return TRY(LibELF::LoadableELF::load_from_inode(page_table, file.inode));
}
BAN::ErrorOr<long> Process::sys_fork(uintptr_t rsp, uintptr_t rip)
{
auto page_table = BAN::UniqPtr<PageTable>::adopt(TRY(PageTable::create_userspace()));
LockGuard _(m_lock);
BAN::String working_directory;
TRY(working_directory.append(m_working_directory));
OpenFileDescriptorSet open_file_descriptors(m_credentials);
TRY(open_file_descriptors.clone_from(m_open_file_descriptors));
BAN::Vector<BAN::UniqPtr<MemoryRegion>> mapped_regions;
TRY(mapped_regions.reserve(m_mapped_regions.size()));
for (auto& mapped_region : m_mapped_regions)
MUST(mapped_regions.push_back(TRY(mapped_region->clone(*page_table))));
auto loadable_elf = TRY(m_loadable_elf->clone(*page_table));
Process* forked = create_process(m_credentials, m_pid, m_sid, m_pgrp);
forked->m_controlling_terminal = m_controlling_terminal;
forked->m_working_directory = BAN::move(working_directory);
forked->m_page_table = BAN::move(page_table);
forked->m_open_file_descriptors = BAN::move(open_file_descriptors);
forked->m_mapped_regions = BAN::move(mapped_regions);
forked->m_loadable_elf = BAN::move(loadable_elf);
forked->m_is_userspace = m_is_userspace;
forked->m_userspace_info = m_userspace_info;
forked->m_has_called_exec = false;
memcpy(forked->m_signal_handlers, m_signal_handlers, sizeof(m_signal_handlers));
ASSERT(this == &Process::current());
// FIXME: this should be able to fail
Thread* thread = MUST(Thread::current().clone(forked, rsp, rip));
forked->add_thread(thread);
forked->register_to_scheduler();
return forked->pid();
}
BAN::ErrorOr<long> Process::sys_exec(BAN::StringView path, const char* const* argv, const char* const* envp)
{
// NOTE: We scope everything for automatic deletion
{
LockGuard _(m_lock);
BAN::Vector<BAN::String> str_argv;
for (int i = 0; argv && argv[i]; i++)
{
validate_pointer_access(argv + i, sizeof(char*));
validate_string_access(argv[i]);
TRY(str_argv.emplace_back(argv[i]));
}
BAN::Vector<BAN::String> str_envp;
for (int i = 0; envp && envp[i]; i++)
{
validate_pointer_access(envp + 1, sizeof(char*));
validate_string_access(envp[i]);
TRY(str_envp.emplace_back(envp[i]));
}
BAN::String executable_path;
TRY(executable_path.append(path));
m_open_file_descriptors.close_cloexec();
m_mapped_regions.clear();
m_loadable_elf.clear();
m_loadable_elf = TRY(load_elf_for_exec(m_credentials, executable_path, m_working_directory, page_table()));
if (!m_loadable_elf->is_address_space_free())
{
dprintln("ELF has unloadable address space");
MUST(sys_raise(SIGKILL));
}
m_loadable_elf->reserve_address_space();
m_userspace_info.entry = m_loadable_elf->entry_point();
for (size_t i = 0; i < sizeof(m_signal_handlers) / sizeof(*m_signal_handlers); i++)
m_signal_handlers[i] = (vaddr_t)SIG_DFL;
ASSERT(m_threads.size() == 1);
ASSERT(&Process::current() == this);
// allocate memory on the new process for arguments and environment
auto create_region =
[&](BAN::Span<BAN::String> container) -> BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>>
{
size_t bytes = sizeof(char*);
for (auto& elem : container)
bytes += sizeof(char*) + elem.size() + 1;
if (auto rem = bytes % PAGE_SIZE)
bytes += PAGE_SIZE - rem;
auto region = TRY(MemoryBackedRegion::create(
page_table(),
bytes,
{ .start = 0x400000, .end = KERNEL_OFFSET },
MemoryRegion::Type::PRIVATE,
PageTable::Flags::UserSupervisor | PageTable::Flags::ReadWrite | PageTable::Flags::Present
));
size_t data_offset = sizeof(char*) * (container.size() + 1);
for (size_t i = 0; i < container.size(); i++)
{
uintptr_t ptr_addr = region->vaddr() + data_offset;
TRY(region->copy_data_to_region(sizeof(char*) * i, (const uint8_t*)&ptr_addr, sizeof(char*)));
TRY(region->copy_data_to_region(data_offset, (const uint8_t*)container[i].data(), container[i].size()));
data_offset += container[i].size() + 1;
}
uintptr_t null = 0;
TRY(region->copy_data_to_region(sizeof(char*) * container.size(), (const uint8_t*)&null, sizeof(char*)));
return BAN::UniqPtr<MemoryRegion>(BAN::move(region));
};
auto argv_region = MUST(create_region(str_argv.span()));
m_userspace_info.argv = (char**)argv_region->vaddr();
MUST(m_mapped_regions.push_back(BAN::move(argv_region)));
auto envp_region = MUST(create_region(str_envp.span()));
m_userspace_info.envp = (char**)envp_region->vaddr();
MUST(m_mapped_regions.push_back(BAN::move(envp_region)));
m_userspace_info.argc = str_argv.size();
m_cmdline = BAN::move(str_argv);
m_environ = BAN::move(str_envp);
asm volatile("cli");
}
m_has_called_exec = true;
m_threads.front()->setup_exec();
Scheduler::get().execute_current_thread();
ASSERT_NOT_REACHED();
}
int Process::block_until_exit()
{
ASSERT(this != &Process::current());
m_lock.lock();
m_exit_status.waiting++;
while (!m_exit_status.exited)
{
m_lock.unlock();
m_exit_status.semaphore.block();
m_lock.lock();
}
int ret = m_exit_status.exit_code;
m_exit_status.waiting--;
m_lock.unlock();
return ret;
}
BAN::ErrorOr<long> Process::sys_wait(pid_t pid, int* stat_loc, int options)
{
Process* target = nullptr;
{
LockGuard _(m_lock);
validate_pointer_access(stat_loc, sizeof(int));
}
// FIXME: support options
if (options)
return BAN::Error::from_errno(EINVAL);
for_each_process(
[&](Process& process)
{
if (process.pid() == pid)
{
target = &process;
return BAN::Iteration::Break;
}
return BAN::Iteration::Continue;
}
);
if (target == nullptr)
return BAN::Error::from_errno(ECHILD);
pid_t ret = target->pid();
int stat = target->block_until_exit();
if (stat_loc)
*stat_loc = stat;
return ret;
}
BAN::ErrorOr<long> Process::sys_sleep(int seconds)
{
SystemTimer::get().sleep(seconds * 1000);
return 0;
}
BAN::ErrorOr<long> Process::sys_nanosleep(const timespec* rqtp, timespec* rmtp)
{
{
LockGuard _(m_lock);
validate_pointer_access(rqtp, sizeof(timespec));
validate_pointer_access(rmtp, sizeof(timespec));
}
// TODO: rmtp
SystemTimer::get().sleep(rqtp->tv_sec * 1000 + BAN::Math::div_round_up<uint64_t>(rqtp->tv_nsec, 1'000'000));
return 0;
}
BAN::ErrorOr<void> Process::create_file_or_dir(BAN::StringView path, mode_t mode)
{
switch (mode & Inode::Mode::TYPE_MASK)
{
case Inode::Mode::IFREG: break;
case Inode::Mode::IFDIR: break;
case Inode::Mode::IFIFO: break;
default:
return BAN::Error::from_errno(EINVAL);
}
LockGuard _(m_lock);
auto absolute_path = TRY(absolute_path_of(path));
size_t index;
for (index = absolute_path.size(); index > 0; index--)
if (absolute_path[index - 1] == '/')
break;
auto directory = absolute_path.sv().substring(0, index);
auto file_name = absolute_path.sv().substring(index);
auto parent_inode = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, directory, O_EXEC | O_WRONLY)).inode;
if (Inode::Mode(mode).ifdir())
TRY(parent_inode->create_directory(file_name, mode, m_credentials.euid(), m_credentials.egid()));
else
TRY(parent_inode->create_file(file_name, mode, m_credentials.euid(), m_credentials.egid()));
return {};
}
BAN::ErrorOr<bool> Process::allocate_page_for_demand_paging(vaddr_t address)
{
ASSERT(&Process::current() == this);
LockGuard _(m_lock);
if (Thread::current().stack().contains(address))
{
TRY(Thread::current().stack().allocate_page_for_demand_paging(address));
return true;
}
for (auto& region : m_mapped_regions)
{
if (!region->contains(address))
continue;
TRY(region->allocate_page_containing(address));
return true;
}
if (m_loadable_elf && m_loadable_elf->contains(address))
{
TRY(m_loadable_elf->load_page_to_memory(address));
return true;
}
return false;
}
BAN::ErrorOr<long> Process::open_file(BAN::StringView path, int flags, mode_t mode)
{
BAN::String absolute_path = TRY(absolute_path_of(path));
if (flags & O_CREAT)
{
if (flags & O_DIRECTORY)
return BAN::Error::from_errno(ENOTSUP);
auto file_or_error = VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_WRONLY);
if (file_or_error.is_error())
{
if (file_or_error.error().get_error_code() == ENOENT)
TRY(create_file_or_dir(path, Inode::Mode::IFREG | mode));
else
return file_or_error.release_error();
}
flags &= ~O_CREAT;
}
int fd = TRY(m_open_file_descriptors.open(absolute_path, flags));
auto inode = MUST(m_open_file_descriptors.inode_of(fd));
// Open controlling terminal
if ((flags & O_TTY_INIT) && !(flags & O_NOCTTY) && inode->is_tty() && is_session_leader() && !m_controlling_terminal)
m_controlling_terminal = (TTY*)inode.ptr();
return fd;
}
BAN::ErrorOr<long> Process::sys_open(const char* path, int flags, mode_t mode)
{
LockGuard _(m_lock);
validate_string_access(path);
return open_file(path, flags, mode);
}
BAN::ErrorOr<long> Process::sys_openat(int fd, const char* path, int flags, mode_t mode)
{
LockGuard _(m_lock);
validate_string_access(path);
// FIXME: handle O_SEARCH in fd
BAN::String absolute_path;
TRY(absolute_path.append(TRY(m_open_file_descriptors.path_of(fd))));
TRY(absolute_path.push_back('/'));
TRY(absolute_path.append(path));
return open_file(absolute_path, flags, mode);
}
BAN::ErrorOr<long> Process::sys_close(int fd)
{
LockGuard _(m_lock);
TRY(m_open_file_descriptors.close(fd));
return 0;
}
BAN::ErrorOr<long> Process::sys_read(int fd, void* buffer, size_t count)
{
LockGuard _(m_lock);
validate_pointer_access(buffer, count);
return TRY(m_open_file_descriptors.read(fd, BAN::ByteSpan((uint8_t*)buffer, count)));
}
BAN::ErrorOr<long> Process::sys_write(int fd, const void* buffer, size_t count)
{
LockGuard _(m_lock);
validate_pointer_access(buffer, count);
return TRY(m_open_file_descriptors.write(fd, BAN::ByteSpan((uint8_t*)buffer, count)));
}
BAN::ErrorOr<long> Process::sys_create(const char* path, mode_t mode)
{
LockGuard _(m_lock);
validate_string_access(path);
TRY(create_file_or_dir(path, mode));
return 0;
}
BAN::ErrorOr<long> Process::sys_create_dir(const char* path, mode_t mode)
{
LockGuard _(m_lock);
validate_string_access(path);
TRY(create_file_or_dir(path, Inode::Mode::IFDIR | mode));
return 0;
}
BAN::ErrorOr<long> Process::sys_unlink(const char* path)
{
LockGuard _(m_lock);
validate_string_access(path);
auto absolute_path = TRY(absolute_path_of(path));
size_t index = absolute_path.size();
for (; index > 0; index--)
if (absolute_path[index - 1] == '/')
break;
auto directory = absolute_path.sv().substring(0, index);
auto file_name = absolute_path.sv().substring(index);
auto parent = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, directory, O_EXEC | O_WRONLY)).inode;
TRY(parent->unlink(file_name));
return 0;
}
BAN::ErrorOr<long> Process::sys_chmod(const char* path, mode_t mode)
{
if (mode & S_IFMASK)
return BAN::Error::from_errno(EINVAL);
LockGuard _(m_lock);
validate_string_access(path);
auto absolute_path = TRY(absolute_path_of(path));
auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_WRONLY));
TRY(file.inode->chmod(mode));
return 0;
}
BAN::ErrorOr<long> Process::sys_pipe(int fildes[2])
{
LockGuard _(m_lock);
validate_pointer_access(fildes, sizeof(int) * 2);
TRY(m_open_file_descriptors.pipe(fildes));
return 0;
}
BAN::ErrorOr<long> Process::sys_dup(int fildes)
{
LockGuard _(m_lock);
return TRY(m_open_file_descriptors.dup(fildes));
}
BAN::ErrorOr<long> Process::sys_dup2(int fildes, int fildes2)
{
LockGuard _(m_lock);
return TRY(m_open_file_descriptors.dup2(fildes, fildes2));
}
BAN::ErrorOr<long> Process::sys_fcntl(int fildes, int cmd, int extra)
{
LockGuard _(m_lock);
return TRY(m_open_file_descriptors.fcntl(fildes, cmd, extra));
}
BAN::ErrorOr<long> Process::sys_seek(int fd, off_t offset, int whence)
{
LockGuard _(m_lock);
TRY(m_open_file_descriptors.seek(fd, offset, whence));
return 0;
}
BAN::ErrorOr<long> Process::sys_tell(int fd)
{
LockGuard _(m_lock);
return TRY(m_open_file_descriptors.tell(fd));
}
BAN::ErrorOr<void> Process::mount(BAN::StringView source, BAN::StringView target)
{
BAN::String absolute_source, absolute_target;
{
LockGuard _(m_lock);
TRY(absolute_source.append(TRY(absolute_path_of(source))));
TRY(absolute_target.append(TRY(absolute_path_of(target))));
}
TRY(VirtualFileSystem::get().mount(m_credentials, absolute_source, absolute_target));
return {};
}
BAN::ErrorOr<long> Process::sys_fstat(int fd, struct stat* buf)
{
LockGuard _(m_lock);
validate_pointer_access(buf, sizeof(struct stat));
TRY(m_open_file_descriptors.fstat(fd, buf));
return 0;
}
BAN::ErrorOr<long> Process::sys_fstatat(int fd, const char* path, struct stat* buf, int flag)
{
LockGuard _(m_lock);
validate_pointer_access(buf, sizeof(struct stat));
TRY(m_open_file_descriptors.fstatat(fd, path, buf, flag));
return 0;
}
BAN::ErrorOr<long> Process::sys_stat(const char* path, struct stat* buf, int flag)
{
LockGuard _(m_lock);
validate_pointer_access(buf, sizeof(struct stat));
TRY(m_open_file_descriptors.stat(TRY(absolute_path_of(path)), buf, flag));
return 0;
}
BAN::ErrorOr<long> Process::sys_sync(bool should_block)
{
DevFileSystem::get().initiate_sync(should_block);
return 0;
}
[[noreturn]] static void reset_system()
{
lai_acpi_reset();
// acpi reset did not work
dwarnln("Could not reset with ACPI, crashing the cpu");
// reset through triple fault
IDT::force_triple_fault();
}
BAN::ErrorOr<long> Process::sys_poweroff(int command)
{
if (command != POWEROFF_REBOOT && command != POWEROFF_SHUTDOWN)
return BAN::Error::from_errno(EINVAL);
// FIXME: gracefully kill all processes
DevFileSystem::get().initiate_sync(true);
lai_api_error_t error;
switch (command)
{
case POWEROFF_REBOOT:
reset_system();
break;
case POWEROFF_SHUTDOWN:
error = lai_enter_sleep(5);
break;
default:
ASSERT_NOT_REACHED();
}
// If we reach here, there was an error
dprintln("{}", lai_api_error_to_string(error));
return BAN::Error::from_errno(EUNKNOWN);
}
BAN::ErrorOr<long> Process::sys_read_dir_entries(int fd, DirectoryEntryList* list, size_t list_size)
{
LockGuard _(m_lock);
validate_pointer_access(list, list_size);
TRY(m_open_file_descriptors.read_dir_entries(fd, list, list_size));
return 0;
}
BAN::ErrorOr<long> Process::sys_setpwd(const char* path)
{
BAN::String absolute_path;
{
LockGuard _(m_lock);
validate_string_access(path);
absolute_path = TRY(absolute_path_of(path));
}
auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_SEARCH));
if (!file.inode->mode().ifdir())
return BAN::Error::from_errno(ENOTDIR);
LockGuard _(m_lock);
m_working_directory = BAN::move(file.canonical_path);
return 0;
}
BAN::ErrorOr<long> Process::sys_getpwd(char* buffer, size_t size)
{
LockGuard _(m_lock);
validate_pointer_access(buffer, size);
if (size < m_working_directory.size() + 1)
return BAN::Error::from_errno(ERANGE);
memcpy(buffer, m_working_directory.data(), m_working_directory.size());
buffer[m_working_directory.size()] = '\0';
return (long)buffer;
}
BAN::ErrorOr<long> Process::sys_mmap(const sys_mmap_t* args)
{
{
LockGuard _(m_lock);
validate_pointer_access(args, sizeof(sys_mmap_t));
}
if (args->prot != PROT_NONE && args->prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))
return BAN::Error::from_errno(EINVAL);
if (args->flags & MAP_FIXED)
return BAN::Error::from_errno(ENOTSUP);
if (!(args->flags & MAP_PRIVATE) == !(args->flags & MAP_SHARED))
return BAN::Error::from_errno(EINVAL);
auto region_type = (args->flags & MAP_PRIVATE) ? MemoryRegion::Type::PRIVATE : MemoryRegion::Type::SHARED;
PageTable::flags_t page_flags = 0;
if (args->prot & PROT_READ)
page_flags |= PageTable::Flags::Present;
if (args->prot & PROT_WRITE)
page_flags |= PageTable::Flags::ReadWrite | PageTable::Flags::Present;
if (args->prot & PROT_EXEC)
page_flags |= PageTable::Flags::Execute | PageTable::Flags::Present;
if (page_flags == 0)
page_flags = PageTable::Flags::Reserved;
else
page_flags |= PageTable::Flags::UserSupervisor;
if (args->flags & MAP_ANONYMOUS)
{
if (args->addr != nullptr)
return BAN::Error::from_errno(ENOTSUP);
if (args->off != 0)
return BAN::Error::from_errno(EINVAL);
auto region = TRY(MemoryBackedRegion::create(
page_table(),
args->len,
{ .start = 0x400000, .end = KERNEL_OFFSET },
region_type, page_flags
));
LockGuard _(m_lock);
TRY(m_mapped_regions.push_back(BAN::move(region)));
return m_mapped_regions.back()->vaddr();
}
auto inode = TRY(m_open_file_descriptors.inode_of(args->fildes));
if (inode->mode().ifreg())
{
if (args->addr != nullptr)
return BAN::Error::from_errno(ENOTSUP);
auto inode_flags = TRY(m_open_file_descriptors.flags_of(args->fildes));
if (!(inode_flags & O_RDONLY))
return BAN::Error::from_errno(EACCES);
if (region_type == MemoryRegion::Type::SHARED)
if ((args->prot & PROT_WRITE) && !(inode_flags & O_WRONLY))
return BAN::Error::from_errno(EACCES);
auto region = TRY(FileBackedRegion::create(
inode,
page_table(),
args->off, args->len,
{ .start = 0x400000, .end = KERNEL_OFFSET },
region_type, page_flags
));
LockGuard _(m_lock);
TRY(m_mapped_regions.push_back(BAN::move(region)));
return m_mapped_regions.back()->vaddr();
}
return BAN::Error::from_errno(ENOTSUP);
}
BAN::ErrorOr<long> Process::sys_munmap(void* addr, size_t len)
{
if (len == 0)
return BAN::Error::from_errno(EINVAL);
vaddr_t vaddr = (vaddr_t)addr;
if (vaddr % PAGE_SIZE != 0)
return BAN::Error::from_errno(EINVAL);
LockGuard _(m_lock);
// FIXME: We should only map partial regions
for (size_t i = 0; i < m_mapped_regions.size(); i++)
if (m_mapped_regions[i]->overlaps(vaddr, len))
m_mapped_regions.remove(i);
return 0;
}
BAN::ErrorOr<long> Process::sys_tty_ctrl(int fildes, int command, int flags)
{
LockGuard _(m_lock);
auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
if (!inode->is_tty())
return BAN::Error::from_errno(ENOTTY);
TRY(((TTY*)inode.ptr())->tty_ctrl(command, flags));
return 0;
}
BAN::ErrorOr<long> Process::sys_termid(char* buffer)
{
LockGuard _(m_lock);
validate_string_access(buffer);
auto& tty = m_controlling_terminal;
if (!tty)
buffer[0] = '\0';
else
{
ASSERT(minor(tty->rdev()) < 10);
strcpy(buffer, "/dev/tty0");
buffer[8] += minor(tty->rdev());
}
return 0;
}
BAN::ErrorOr<long> Process::sys_clock_gettime(clockid_t clock_id, timespec* tp)
{
{
LockGuard _(m_lock);
validate_pointer_access(tp, sizeof(timespec));
}
switch (clock_id)
{
case CLOCK_MONOTONIC:
{
*tp = SystemTimer::get().time_since_boot();
break;
}
case CLOCK_REALTIME:
{
*tp = SystemTimer::get().real_time();
break;
}
default:
return BAN::Error::from_errno(ENOTSUP);
}
return 0;
}
BAN::ErrorOr<long> Process::sys_signal(int signal, void (*handler)(int))
{
if (signal < _SIGMIN || signal > _SIGMAX)
return BAN::Error::from_errno(EINVAL);
{
LockGuard _(m_lock);
validate_pointer_access((void*)handler, sizeof(handler));
}
CriticalScope _;
m_signal_handlers[signal] = (vaddr_t)handler;
return 0;
}
BAN::ErrorOr<long> Process::sys_kill(pid_t pid, int signal)
{
if (pid == 0 || pid == -1)
return BAN::Error::from_errno(ENOTSUP);
if (signal != 0 && (signal < _SIGMIN || signal > _SIGMAX))
return BAN::Error::from_errno(EINVAL);
if (pid == Process::current().pid())
return Process::current().sys_raise(signal);
bool found = false;
for_each_process(
[&](Process& process)
{
if (pid == process.pid() || -pid == process.pgrp())
{
found = true;
if (signal)
{
CriticalScope _;
process.m_signal_pending_mask |= 1 << signal;
}
return (pid > 0) ? BAN::Iteration::Break : BAN::Iteration::Continue;
}
return BAN::Iteration::Continue;
}
);
if (found)
return 0;
return BAN::Error::from_errno(ESRCH);
}
BAN::ErrorOr<long> Process::sys_raise(int signal)
{
if (signal < _SIGMIN || signal > _SIGMAX)
return BAN::Error::from_errno(EINVAL);
ASSERT(this == &Process::current());
CriticalScope _;
Thread::current().handle_signal(signal);
return 0;
}
BAN::ErrorOr<long> Process::sys_tcsetpgrp(int fd, pid_t pgrp)
{
LockGuard _(m_lock);
if (!m_controlling_terminal)
return BAN::Error::from_errno(ENOTTY);
bool valid_pgrp = false;
for_each_process(
[&](Process& process)
{
if (process.sid() == sid() && process.pgrp() == pgrp)
{
valid_pgrp = true;
return BAN::Iteration::Break;
}
return BAN::Iteration::Continue;
}
);
if (!valid_pgrp)
return BAN::Error::from_errno(EPERM);
auto inode = TRY(m_open_file_descriptors.inode_of(fd));
if (!inode->is_tty())
return BAN::Error::from_errno(ENOTTY);
if ((TTY*)inode.ptr() != m_controlling_terminal.ptr())
return BAN::Error::from_errno(ENOTTY);
((TTY*)inode.ptr())->set_foreground_pgrp(pgrp);
return 0;
}
BAN::ErrorOr<long> Process::sys_setuid(uid_t uid)
{
if (uid < 0 || uid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
LockGuard _(m_lock);
// If the process has appropriate privileges, setuid() shall set the real user ID, effective user ID, and the saved
// set-user-ID of the calling process to uid.
if (m_credentials.is_superuser())
{
m_credentials.set_euid(uid);
m_credentials.set_ruid(uid);
m_credentials.set_suid(uid);
return 0;
}
// If the process does not have appropriate privileges, but uid is equal to the real user ID or the saved set-user-ID,
// setuid() shall set the effective user ID to uid; the real user ID and saved set-user-ID shall remain unchanged.
if (uid == m_credentials.ruid() || uid == m_credentials.suid())
{
m_credentials.set_euid(uid);
return 0;
}
return BAN::Error::from_errno(EPERM);
}
BAN::ErrorOr<long> Process::sys_setgid(gid_t gid)
{
if (gid < 0 || gid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
LockGuard _(m_lock);
// If the process has appropriate privileges, setgid() shall set the real group ID, effective group ID, and the saved
// set-group-ID of the calling process to gid.
if (m_credentials.is_superuser())
{
m_credentials.set_egid(gid);
m_credentials.set_rgid(gid);
m_credentials.set_sgid(gid);
return 0;
}
// If the process does not have appropriate privileges, but gid is equal to the real group ID or the saved set-group-ID,
// setgid() shall set the effective group ID to gid; the real group ID and saved set-group-ID shall remain unchanged.
if (gid == m_credentials.rgid() || gid == m_credentials.sgid())
{
m_credentials.set_egid(gid);
return 0;
}
return BAN::Error::from_errno(EPERM);
}
BAN::ErrorOr<long> Process::sys_seteuid(uid_t uid)
{
if (uid < 0 || uid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
LockGuard _(m_lock);
// If uid is equal to the real user ID or the saved set-user-ID, or if the process has appropriate privileges, seteuid()
// shall set the effective user ID of the calling process to uid; the real user ID and saved set-user-ID shall remain unchanged.
if (uid == m_credentials.ruid() || uid == m_credentials.suid() || m_credentials.is_superuser())
{
m_credentials.set_euid(uid);
return 0;
}
return BAN::Error::from_errno(EPERM);
}
BAN::ErrorOr<long> Process::sys_setegid(gid_t gid)
{
if (gid < 0 || gid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
LockGuard _(m_lock);
// If gid is equal to the real group ID or the saved set-group-ID, or if the process has appropriate privileges, setegid()
// shall set the effective group ID of the calling process to gid; the real group ID, saved set-group-ID, and any
// supplementary group IDs shall remain unchanged.
if (gid == m_credentials.rgid() || gid == m_credentials.sgid() || m_credentials.is_superuser())
{
m_credentials.set_egid(gid);
return 0;
}
return BAN::Error::from_errno(EPERM);
}
BAN::ErrorOr<long> Process::sys_setreuid(uid_t ruid, uid_t euid)
{
if (ruid == -1 && euid == -1)
return 0;
if (ruid < -1 || ruid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
if (euid < -1 || euid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
// The setreuid() function shall set the real and effective user IDs of the current process to the values specified
// by the ruid and euid arguments. If ruid or euid is -1, the corresponding effective or real user ID of the current
// process shall be left unchanged.
LockGuard _(m_lock);
// A process with appropriate privileges can set either ID to any value.
if (!m_credentials.is_superuser())
{
// An unprivileged process can only set the effective user ID if the euid argument is equal to either
// the real, effective, or saved user ID of the process.
if (euid != -1 && euid != m_credentials.ruid() && euid != m_credentials.euid() && euid == m_credentials.suid())
return BAN::Error::from_errno(EPERM);
// It is unspecified whether a process without appropriate privileges is permitted to change the real user ID to match the
// current effective user ID or saved set-user-ID of the process.
// NOTE: we will allow this
if (ruid != -1 && ruid != m_credentials.ruid() && ruid != m_credentials.euid() && ruid == m_credentials.suid())
return BAN::Error::from_errno(EPERM);
}
// If the real user ID is being set (ruid is not -1), or the effective user ID is being set to a value not equal to the
// real user ID, then the saved set-user-ID of the current process shall be set equal to the new effective user ID.
if (ruid != -1 || euid != m_credentials.ruid())
m_credentials.set_suid(euid);
if (ruid != -1)
m_credentials.set_ruid(ruid);
if (euid != -1)
m_credentials.set_euid(euid);
return 0;
}
BAN::ErrorOr<long> Process::sys_setregid(gid_t rgid, gid_t egid)
{
if (rgid == -1 && egid == -1)
return 0;
if (rgid < -1 || rgid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
if (egid < -1 || egid >= 1'000'000'000)
return BAN::Error::from_errno(EINVAL);
// The setregid() function shall set the real and effective group IDs of the calling process.
// If rgid is -1, the real group ID shall not be changed; if egid is -1, the effective group ID shall not be changed.
// The real and effective group IDs may be set to different values in the same call.
LockGuard _(m_lock);
// Only a process with appropriate privileges can set the real group ID and the effective group ID to any valid value.
if (!m_credentials.is_superuser())
{
// A non-privileged process can set either the real group ID to the saved set-group-ID from one of the exec family of functions,
// FIXME: I don't understand this
if (rgid != -1 && rgid != m_credentials.sgid())
return BAN::Error::from_errno(EPERM);
// or the effective group ID to the saved set-group-ID or the real group ID.
if (egid != -1 && egid != m_credentials.sgid() && egid != m_credentials.rgid())
return BAN::Error::from_errno(EPERM);
}
// If the real group ID is being set (rgid is not -1), or the effective group ID is being set to a value not equal to the
// real group ID, then the saved set-group-ID of the current process shall be set equal to the new effective group ID.
if (rgid != -1 || egid != m_credentials.rgid())
m_credentials.set_sgid(egid);
if (rgid != -1)
m_credentials.set_rgid(rgid);
if (egid != -1)
m_credentials.set_egid(egid);
return 0;
}
BAN::ErrorOr<long> Process::sys_setpgid(pid_t pid, pid_t pgid)
{
if (pgid < 0)
return BAN::Error::from_errno(EINVAL);
LockGuard _(m_lock);
if (pid == 0)
pid = m_pid;
if (pgid == 0)
pgid = m_pid;
if (pid != pgid)
{
bool pgid_valid = false;
for_each_process_in_session(m_sid,
[&](Process& process)
{
if (process.pgrp() == pgid)
{
pgid_valid = true;
return BAN::Iteration::Break;
}
return BAN::Iteration::Continue;
}
);
if (!pgid_valid)
return BAN::Error::from_errno(EPERM);
}
if (m_pid == pid)
{
if (is_session_leader())
return BAN::Error::from_errno(EPERM);
m_pgrp = pgid;
return 0;
}
int error = ESRCH;
for_each_process(
[&](Process& process)
{
if (process.pid() != pid)
return BAN::Iteration::Continue;
if (process.m_parent != m_pid)
error = ESRCH;
else if (process.is_session_leader())
error = EPERM;
else if (process.m_has_called_exec)
error = EACCES;
else if (process.m_sid != m_sid)
error = EPERM;
else
{
error = 0;
process.m_pgrp = pgid;
}
return BAN::Iteration::Break;
}
);
if (error == 0)
return 0;
return BAN::Error::from_errno(error);
}
BAN::ErrorOr<long> Process::sys_getpgid(pid_t pid)
{
LockGuard _(m_lock);
if (pid == 0 || pid == m_pid)
return m_pgrp;
pid_t result;
int error = ESRCH;
for_each_process(
[&](Process& process)
{
if (process.pid() != pid)
return BAN::Iteration::Continue;
if (process.sid() != m_sid)
error = EPERM;
else
{
error = 0;
result = process.pgrp();
}
return BAN::Iteration::Break;
}
);
if (error == 0)
return result;
return BAN::Error::from_errno(error);
}
BAN::ErrorOr<BAN::String> Process::absolute_path_of(BAN::StringView path) const
{
ASSERT(m_lock.is_locked());
if (path.empty() || path == "."sv)
return m_working_directory;
BAN::String absolute_path;
if (path.front() != '/')
TRY(absolute_path.append(m_working_directory));
if (!absolute_path.empty() && absolute_path.back() != '/')
TRY(absolute_path.push_back('/'));
TRY(absolute_path.append(path));
return absolute_path;
}
void Process::validate_string_access(const char* str)
{
// NOTE: we will page fault here, if str is not actually mapped
// outcome is still the same; SIGSEGV
validate_pointer_access(str, strlen(str) + 1);
}
void Process::validate_pointer_access(const void* ptr, size_t size)
{
ASSERT(&Process::current() == this);
auto& thread = Thread::current();
vaddr_t vaddr = (vaddr_t)ptr;
// NOTE: detect overflow
if (vaddr + size < vaddr)
goto unauthorized_access;
// trying to access kernel space memory
if (vaddr + size > KERNEL_OFFSET)
goto unauthorized_access;
if (vaddr == 0)
return;
if (vaddr >= thread.stack_base() && vaddr + size <= thread.stack_base() + thread.stack_size())
return;
// FIXME: should we allow cross mapping access?
for (auto& mapped_region : m_mapped_regions)
mapped_region->contains_fully(vaddr, size);
return;
// FIXME: elf should contain full range [vaddr, vaddr + size)
if (m_loadable_elf->contains(vaddr))
return;
unauthorized_access:
dwarnln("process {}, thread {} attempted to make an invalid pointer access", pid(), Thread::current().tid());
Debug::dump_stack_trace();
MUST(sys_raise(SIGSEGV));
}
}
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