From a2f11835994ed5bcd6d66c7205947cc482231b08 Mon Sep 17 00:00:00 2001 From: Shawn Landden Date: Tue, 5 May 2015 09:07:16 -0700 Subject: [PATCH] can.h: make padding given by gcc explicit The current definition of struct can_frame has a 16-byte size, with 8-byte alignment, but the 3 bytes of padding are not explicit like the similar 2 bytes of padding of struct canfd_frame. Make it explicit so it is easier to read. Signed-off-by: Shawn Landden Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- Documentation/networking/can.txt | 3 +++ include/uapi/linux/can.h | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt index 5abad1e921ca..b48d4a149411 100644 --- a/Documentation/networking/can.txt +++ b/Documentation/networking/can.txt @@ -268,6 +268,9 @@ solution for a couple of reasons: struct can_frame { canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */ __u8 can_dlc; /* frame payload length in byte (0 .. 8) */ + __u8 __pad; /* padding */ + __u8 __res0; /* reserved / padding */ + __u8 __res1; /* reserved / padding */ __u8 data[8] __attribute__((aligned(8))); }; diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h index 41892f720057..9692cda5f8fc 100644 --- a/include/uapi/linux/can.h +++ b/include/uapi/linux/can.h @@ -95,11 +95,17 @@ typedef __u32 can_err_mask_t; * @can_dlc: frame payload length in byte (0 .. 8) aka data length code * N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1 * mapping of the 'data length code' to the real payload length + * @__pad: padding + * @__res0: reserved / padding + * @__res1: reserved / padding * @data: CAN frame payload (up to 8 byte) */ struct can_frame { canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */ __u8 can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */ + __u8 __pad; /* padding */ + __u8 __res0; /* reserved / padding */ + __u8 __res1; /* reserved / padding */ __u8 data[CAN_MAX_DLEN] __attribute__((aligned(8))); }; -- 2.20.1