banan-os/kernel/kernel/Thread.cpp

360 lines
9.1 KiB
C++

#include <BAN/Errors.h>
#include <BAN/ScopeGuard.h>
#include <kernel/GDT.h>
#include <kernel/InterruptController.h>
#include <kernel/InterruptStack.h>
#include <kernel/Memory/kmalloc.h>
#include <kernel/Memory/PageTableScope.h>
#include <kernel/Process.h>
#include <kernel/Scheduler.h>
#include <kernel/Thread.h>
namespace Kernel
{
extern "C" void thread_userspace_trampoline(uint64_t rsp, uint64_t rip, int argc, char** argv, char** envp);
extern "C" uintptr_t read_rip();
extern "C" void signal_trampoline();
template<typename T>
static void write_to_stack(uintptr_t& rsp, const T& value)
{
rsp -= sizeof(uintptr_t);
if constexpr(sizeof(T) < sizeof(uintptr_t))
*(uintptr_t*)rsp = (uintptr_t)value;
else
memcpy((void*)rsp, (void*)&value, sizeof(uintptr_t));
}
void Thread::terminate()
{
CriticalScope _;
ASSERT(this == &Thread::current());
m_state = Thread::State::Terminated;
if (this == &Thread::current())
Scheduler::get().execute_current_thread();
}
static pid_t s_next_tid = 1;
BAN::ErrorOr<Thread*> Thread::create_kernel(entry_t entry, void* data, Process* process)
{
// Create the thread object
Thread* thread = new Thread(s_next_tid++, process);
if (thread == nullptr)
return BAN::Error::from_errno(ENOMEM);
BAN::ScopeGuard thread_deleter([thread] { delete thread; });
// Initialize stack and registers
thread->m_stack = TRY(VirtualRange::create_kmalloc(m_kernel_stack_size));
thread->m_rsp = thread->stack_base() + thread->stack_size();
thread->m_rip = (uintptr_t)entry;
// Initialize stack for returning
write_to_stack(thread->m_rsp, nullptr); // alignment
write_to_stack(thread->m_rsp, thread);
write_to_stack(thread->m_rsp, &Thread::on_exit);
write_to_stack(thread->m_rsp, data);
thread_deleter.disable();
return thread;
}
BAN::ErrorOr<Thread*> Thread::create_userspace(Process* process)
{
ASSERT(process);
// Create the thread object
Thread* thread = new Thread(s_next_tid++, process);
if (thread == nullptr)
return BAN::Error::from_errno(ENOMEM);
BAN::ScopeGuard thread_deleter([thread] { delete thread; });
thread->m_is_userspace = true;
thread->m_stack = TRY(VirtualRange::create_to_vaddr_range(
process->page_table(),
0x300000, KERNEL_OFFSET,
m_userspace_stack_size,
PageTable::Flags::UserSupervisor | PageTable::Flags::ReadWrite | PageTable::Flags::Present,
true
));
thread->m_interrupt_stack = TRY(VirtualRange::create_to_vaddr_range(
process->page_table(),
0x300000, KERNEL_OFFSET,
m_interrupt_stack_size,
PageTable::Flags::ReadWrite | PageTable::Flags::Present,
true
));
thread->setup_exec();
thread_deleter.disable();
return thread;
}
Thread::Thread(pid_t tid, Process* process)
: m_tid(tid), m_process(process)
{}
Thread& Thread::current()
{
return Scheduler::get().current_thread();
}
Process& Thread::process()
{
ASSERT(m_process);
return *m_process;
}
Thread::~Thread()
{
}
BAN::ErrorOr<Thread*> Thread::clone(Process* new_process, uintptr_t rsp, uintptr_t rip)
{
ASSERT(m_is_userspace);
ASSERT(m_state == State::Executing);
Thread* thread = new Thread(s_next_tid++, new_process);
if (thread == nullptr)
return BAN::Error::from_errno(ENOMEM);
BAN::ScopeGuard thread_deleter([thread] { delete thread; });
thread->m_is_userspace = true;
thread->m_interrupt_stack = TRY(m_interrupt_stack->clone(new_process->page_table()));
thread->m_stack = TRY(m_stack->clone(new_process->page_table()));
thread->m_state = State::Executing;
thread->m_rip = rip;
thread->m_rsp = rsp;
thread_deleter.disable();
return thread;
}
void Thread::setup_exec()
{
ASSERT(is_userspace());
m_state = State::NotStarted;
static entry_t entry_trampoline(
[](void*)
{
const auto& info = Process::current().userspace_info();
thread_userspace_trampoline(Thread::current().rsp(), info.entry, info.argc, info.argv, info.envp);
ASSERT_NOT_REACHED();
}
);
m_rsp = stack_base() + stack_size();
m_rip = (uintptr_t)entry_trampoline;
// Signal mask is inherited
// Setup stack for returning
{
// FIXME: don't use PageTableScope
PageTableScope _(process().page_table());
write_to_stack(m_rsp, nullptr); // alignment
write_to_stack(m_rsp, this);
write_to_stack(m_rsp, &Thread::on_exit);
write_to_stack(m_rsp, nullptr);
}
}
void Thread::setup_process_cleanup()
{
m_state = State::NotStarted;
static entry_t entry(
[](void* process)
{
((Process*)process)->cleanup_function();
Scheduler::get().delete_current_process_and_thread();
ASSERT_NOT_REACHED();
}
);
m_rsp = stack_base() + stack_size();
m_rip = (uintptr_t)entry;
m_signal_pending_mask = 0;
m_signal_block_mask = ~0ull;
// Setup stack for returning
{
// FIXME: don't use PageTableScope
PageTableScope _(process().page_table());
write_to_stack(m_rsp, nullptr); // alignment
write_to_stack(m_rsp, this);
write_to_stack(m_rsp, &Thread::on_exit);
write_to_stack(m_rsp, m_process);
}
}
bool Thread::is_interrupted_by_signal()
{
while (can_add_signal_to_execute())
handle_signal();
return will_execute_signal();
}
bool Thread::can_add_signal_to_execute() const
{
if (!is_userspace() || m_state != State::Executing)
return false;
auto& interrupt_stack = *reinterpret_cast<InterruptStack*>(interrupt_stack_base() + interrupt_stack_size() - sizeof(InterruptStack));
if (!GDT::is_user_segment(interrupt_stack.cs))
return false;
uint64_t full_pending_mask = m_signal_pending_mask | m_process->m_signal_pending_mask;
return full_pending_mask & ~m_signal_block_mask;
}
bool Thread::will_execute_signal() const
{
if (!is_userspace() || m_state != State::Executing)
return false;
auto& interrupt_stack = *reinterpret_cast<InterruptStack*>(interrupt_stack_base() + interrupt_stack_size() - sizeof(InterruptStack));
return interrupt_stack.rip == (uintptr_t)signal_trampoline;
}
void Thread::handle_signal(int signal)
{
ASSERT(!interrupts_enabled());
ASSERT(&Thread::current() == this);
ASSERT(is_userspace());
auto& interrupt_stack = *reinterpret_cast<InterruptStack*>(interrupt_stack_base() + interrupt_stack_size() - sizeof(InterruptStack));
ASSERT(GDT::is_user_segment(interrupt_stack.cs));
if (signal == 0)
{
uint64_t full_pending_mask = m_signal_pending_mask | process().m_signal_pending_mask;
for (signal = _SIGMIN; signal <= _SIGMAX; signal++)
{
uint64_t mask = 1ull << signal;
if ((full_pending_mask & mask) && !(m_signal_block_mask & mask))
break;
}
ASSERT(signal <= _SIGMAX);
}
else
{
ASSERT(signal >= _SIGMIN);
ASSERT(signal <= _SIGMAX);
}
vaddr_t signal_handler = process().m_signal_handlers[signal];
m_signal_pending_mask &= ~(1ull << signal);
process().m_signal_pending_mask &= ~(1ull << signal);
if (signal_handler == (vaddr_t)SIG_IGN)
;
else if (signal_handler != (vaddr_t)SIG_DFL)
{
// call userspace signal handlers
interrupt_stack.rsp -= 128; // skip possible red-zone
write_to_stack(interrupt_stack.rsp, interrupt_stack.rip);
write_to_stack(interrupt_stack.rsp, signal);
write_to_stack(interrupt_stack.rsp, signal_handler);
interrupt_stack.rip = (uintptr_t)signal_trampoline;
}
else
{
switch (signal)
{
// Abnormal termination of the process with additional actions.
case SIGABRT:
case SIGBUS:
case SIGFPE:
case SIGILL:
case SIGQUIT:
case SIGSEGV:
case SIGSYS:
case SIGTRAP:
case SIGXCPU:
case SIGXFSZ:
process().exit(128 + signal, signal | 0x80);
break;
// Abnormal termination of the process
case SIGALRM:
case SIGHUP:
case SIGINT:
case SIGKILL:
case SIGPIPE:
case SIGTERM:
case SIGUSR1:
case SIGUSR2:
case SIGPOLL:
case SIGPROF:
case SIGVTALRM:
process().exit(128 + signal, signal);
break;
// Ignore the signal
case SIGCHLD:
case SIGURG:
break;
// Stop the process:
case SIGTSTP:
case SIGTTIN:
case SIGTTOU:
ASSERT_NOT_REACHED();
// Continue the process, if it is stopped; otherwise, ignore the signal.
case SIGCONT:
ASSERT_NOT_REACHED();
}
}
}
bool Thread::add_signal(int signal)
{
ASSERT(!interrupts_enabled());
uint64_t mask = 1ull << signal;
if (!(m_signal_block_mask & mask))
{
m_signal_pending_mask |= mask;
if (this != &Thread::current())
Scheduler::get().unblock_thread(tid());
return true;
}
return false;
}
bool Thread::block_or_eintr(Semaphore& semaphore)
{
if (is_interrupted_by_signal())
return true;
semaphore.block();
return is_interrupted_by_signal();
}
void Thread::validate_stack() const
{
if (stack_base() <= m_rsp && m_rsp <= stack_base() + stack_size())
return;
if (interrupt_stack_base() <= m_rsp && m_rsp <= interrupt_stack_base() + interrupt_stack_size())
return;
Kernel::panic("rsp {8H}, stack {8H}->{8H}, interrupt_stack {8H}->{8H}", m_rsp,
stack_base(), stack_base() + stack_size(),
interrupt_stack_base(), interrupt_stack_base() + interrupt_stack_size()
);
}
void Thread::on_exit()
{
ASSERT(this == &Thread::current());
terminate();
ASSERT_NOT_REACHED();
}
}