Merge pull request #2482 from hermit-os/fcntl-getfd

fix(fcntl): return 0 on F_GETFD

Author: mkroening

src/syscalls/mod.rs

@@ -684,13 +684,17 @@ pub unsafe extern "C" fn sys_ioctl(fd: RawFd, cmd: i32, argp: *mut core::ffi::c_
 #[hermit_macro::system(errno)]
 #[unsafe(no_mangle)]
 pub extern "C" fn sys_fcntl(fd: i32, cmd: i32, arg: i32) -> i32 {
+	const F_GETFD: i32 = 1;
 	const F_SETFD: i32 = 2;
 	const F_GETFL: i32 = 3;
 	const F_SETFL: i32 = 4;
 	const FD_CLOEXEC: i32 = 1;
 
 	if cmd == F_SETFD && arg == FD_CLOEXEC {
 		0
+	} else if cmd == F_GETFD {
+		// Only the FD_CLOEXEC flag is defined, and it has no effect in hermit, so always return 0
+		0
 	} else if cmd == F_GETFL {
 		let obj = get_object(fd);
 		obj.map_or_else(