Re: [PATCH v2 4/4] serial: Add kserial_rs485 to avoid wasted space due to .padding

From: Jiri Slaby
Date: Tue Aug 30 2022 - 04:02:17 EST


On 30. 08. 22, 9:29, Ilpo Järvinen wrote:
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -31,6 +31,29 @@ struct serial_struct;
...
+ * Must match with struct serial_rs485 in include/uapi/linux/serial.h excluding
+ * the padding.

Have you considered BUILD_BUG_ON() checks with few offset_of()s to enforce the above?

+struct kserial_rs485 {
+ __u32 flags;
+ __u32 delay_rts_before_send;
+ __u32 delay_rts_after_send;
+ struct {
+ __u8 addr_recv;
+ __u8 addr_dest;
+ };
+};

thanks,
--
js
suse labs