kernel: implement eventfs/eventfd

kernel-src/sys/syscalls/eventfd.c

@@ -0,0 +1,40 @@
+#include <kernel/syscalls.h>
+#include <kernel/eventfs.h>
+
+#define EFD_CLOEXEC O_CLOEXEC
+#define EFD_NONBLOCK O_NONBLOCK
+#define EFD_SEMAPHORE 1
+
+#define KNOWN_FLAGS (EFD_CLOEXEC | EFD_NONBLOCK | EFD_SEMAPHORE)
+
+syscallret_t syscall_eventfd(context_t *, size_t initval, int flags) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	if (flags & ~KNOWN_FLAGS) {
+		ret.errno = EINVAL;
+		return ret;
+	}
+
+	vnode_t *vnode;
+	ret.errno = eventfs_create_node(&vnode, initval, flags & EFD_SEMAPHORE);
+	if (ret.errno)
+		return ret;
+
+	file_t *file;
+	int fd;
+	ret.errno = fd_new((flags & EFD_CLOEXEC) ? O_CLOEXEC : 0, &file, &fd);
+	if (ret.errno) {
+		VOP_RELEASE(vnode);
+		return ret;
+	}
+
+	file->vnode = vnode;
+	file->flags = FILE_WRITE | FILE_READ | ((flags & EFD_NONBLOCK) ? O_NONBLOCK : 0);
+	file->offset = 0;
+	file->mode = 0666;
+
+	ret.ret = fd;
+	return ret;
+}