Clean up remaining write_scalar

Author: tiif

src/shims/unix/fd.rs

@@ -573,8 +573,8 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         // We temporarily dup the FD to be able to retain mutable access to `this`.
         let Some(fd) = this.machine.fds.get(fd_num) else {
             trace!("read: FD not found");
-            let res = Scalar::from_target_isize(this.fd_not_found()?, this);
-            this.write_scalar(res, dest)?;
+            let res: i32 = this.fd_not_found()?;
+            this.write_int(res, dest)?;
             return Ok(());
         };
 
@@ -626,6 +626,9 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let Some(fd) = this.machine.fds.get(fd_num) else {
             let res = this.fd_not_found()?;
             this.write_scalar(Scalar::from_target_isize(res, this), dest)?;
+        let Some(fd) = this.machine.fds.get(fd_num) else {
+            let res: i32 = this.fd_not_found()?;
+            this.write_int(res, dest)?;
             return Ok(());
         };
 

src/shims/unix/linux/eventfd.rs

@@ -71,7 +71,6 @@ impl FileDescription for Event {
         let Some(bytes) = bytes.first_chunk_mut::<U64_ARRAY_SIZE>() else {
             let result = Ok(Err(Error::from(ErrorKind::InvalidInput)));
             ecx.read_byte_helper(ptr, bytes.to_vec(), result, dest)?;
-            // TODO: remove the usize later
             return Ok(());
         };
         // Block when counter == 0.