kernel: exit syscall

kernel-src/sys/syscalls/exit.c

@@ -0,0 +1,55 @@
+#include <kernel/syscalls.h>
+#include <kernel/scheduler.h>
+#include <kernel/file.h>
+#include <kernel/vfs.h>
+#include <logging.h>
+#include <semaphore.h>
+
+__attribute__((noreturn)) void syscall_exit(context_t *context, int status) {
+	thread_t *thread = _cpu()->thread; 
+	proc_t *proc = thread->proc;
+	__assert(proc != sched_initproc);
+
+	// TODO stop other threads
+
+	for (int fd = 0; fd < proc->fdcount; ++fd)
+		fd_close(fd);
+
+	spinlock_acquire(&proc->lock);
+
+	VOP_RELEASE(proc->root);
+	VOP_RELEASE(proc->cwd);
+
+	proc->status = status;
+	proc->state = SCHED_PROC_STATE_ZOMBIE;
+	proc_t *lastchild = proc->child;
+
+	spinlock_acquire(&sched_initproc->lock);
+
+	bool haszombie = false;
+
+	while (lastchild && lastchild->sibling) {
+		if (lastchild->state == SCHED_PROC_STATE_ZOMBIE)
+			haszombie = true;
+
+		lastchild->parent = sched_initproc;
+		lastchild = lastchild->sibling;
+	}
+
+	if (lastchild) {
+		if (lastchild->sibling->state == SCHED_PROC_STATE_ZOMBIE)
+			haszombie = true;
+
+		lastchild->sibling = sched_initproc->child;
+		sched_initproc->child = proc->child;
+	}
+
+	spinlock_release(&sched_initproc->lock);
+	spinlock_release(&proc->lock);
+
+	semaphore_signal(&proc->parent->waitsem);
+	if (haszombie)
+		semaphore_signal(&sched_initproc->waitsem);
+
+	sched_threadexit();
+}