Luna/kernel/src/sys/waitpid.cpp
apio e2a77bb3da
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kernel+libc: Add pledge support
2023-08-12 21:38:25 +02:00

91 lines
2.7 KiB
C++

#include "Log.h"
#include "Pledge.h"
#include "memory/MemoryManager.h"
#include "sys/Syscall.h"
#include "thread/Scheduler.h"
#include <bits/waitpid.h>
Result<u64> sys_waitpid(Registers* regs, SyscallArgs args)
{
pid_t pid = (pid_t)args[0];
int* status_ptr = (int*)args[1];
int options = (int)args[2];
Thread* current = Scheduler::current();
TRY(check_pledge(current, Promise::p_stdio));
Thread* thread;
if (pid > 0)
{
thread = TRY(Result<Thread*>::from_option(Scheduler::find_by_pid(pid), ESRCH));
if (thread->parent && thread->parent != current) return err(ECHILD);
if (options & WNOHANG) return err(EAGAIN);
wait_for_child:
if (thread->state != ThreadState::Exited) kernel_wait(pid);
if (current->interrupted)
{
kdbgln("signal: waitpid interrupted by signal");
if (current->will_ignore_pending_signal())
{
current->process_pending_signals(regs);
goto wait_for_child;
}
return err(EINTR);
}
check(thread->state == ThreadState::Exited);
}
else if (pid == -1)
{
if (!Scheduler::has_children(current)) return err(ECHILD);
auto child = Scheduler::find_exited_child(current);
if (!child.has_value())
{
if (options & WNOHANG) return err(EAGAIN);
wait_for_any_child:
kernel_wait(pid);
if (current->interrupted)
{
kdbgln("signal: waitpid interrupted by signal");
if (current->will_ignore_pending_signal())
{
current->process_pending_signals(regs);
goto wait_for_any_child;
}
return err(EINTR);
}
check(current->child_being_waited_for.value_or(-1) != -1);
thread = TRY(Result<Thread*>::from_option(Scheduler::find_by_pid(*current->child_being_waited_for), ESRCH));
check(thread->state == ThreadState::Exited);
}
else
thread = child.value();
}
else // FIXME: Now that we have process groups, implement the cases where pid = 0 and pid < -1.
return err(ENOTSUP);
current->child_being_waited_for = {};
int status = (int)thread->status;
u64 id = thread->id;
current->user_ticks_children += thread->user_ticks_self + thread->user_ticks_children;
current->kernel_ticks_children += thread->kernel_ticks_self + thread->kernel_ticks_children;
thread->state = ThreadState::Dying;
Scheduler::signal_reap_thread();
if (status_ptr)
if (!MemoryManager::copy_to_user_typed(status_ptr, &status)) return err(EFAULT);
return id;
}