[LTP] [PATCH 1/1] pty04: Fix build for kernel headers < v4.2-rc1

[Petr Vorel]

> Hi!
> > The struct added in 6b6b56cf3 ("pty04: Add SLCAN ldisc and check for CVE-2020-11494") uses
> > uint32_t, kernel version always used __u8. Richie, any reason to use uint32_t
> > instead of uint8_t? I does not fixes the problem, I'm just asking, whether
> > different size affect test coverage.

> > struct can_frame {
> > 	canid_t can_id;
> > 	uint32_t can_dlc;
> > 	uint32_t __pad;
> > 	uint32_t __res0;
> > 	uint32_t __res1;
> > 	uint32_t data[CAN_MAX_DLEN] __attribute__((aligned(8)));
> > };

> > 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)));
> > };

> These two structures are for sure incompatible, that should be uint8_t
> instead uint32_t.
OK I'll fix it.
I also add #define CAN_MTU     (sizeof(struct can_frame)), instead of 16 (which
is now correct, but for uint32_t should be 56).

Kind regards,
Petr