Enable syscall restart

kernel/src/syscall/read.rs

@@ -22,16 +22,22 @@ pub fn sys_read(
     // According to <https://man7.org/linux/man-pages/man2/read.2.html>, if
     // the user specified an empty buffer, we should detect errors by checking
     // the file descriptor. If no errors detected, return 0 successfully.
-    let read_len = if buf_len != 0 {
-        let mut writer = ctx
-            .process
-            .root_vmar()
-            .vm_space()
-            .writer(user_buf_addr, buf_len)?;
-        file.read(&mut writer)?
-    } else {
-        file.read_bytes(&mut [])?
-    };
+    let read_len = {
+        if buf_len != 0 {
+            let mut writer = ctx
+                .process
+                .root_vmar()
+                .vm_space()
+                .writer(user_buf_addr, buf_len)?;
+            file.read(&mut writer)
+        } else {
+            file.read_bytes(&mut [])
+        }
+    }
+    .map_err(|err| match err.error() {
+        Errno::EINTR => Error::new(Errno::ERESTARTSYS),
+        _ => err,
+    })?;
 
     Ok(SyscallReturn::Return(read_len as _))
 }