From: Vincent Mailhol <mailhol.vincent@wanadoo.fr> stable inclusion from stable-v4.19.256 commit e5ed6be01b2846c55a3e729a3d0a2d661853a606 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5Q0SQ CVE: NA -------------------------------- [ Upstream commit e70a3263a7eed768d5f947b8f2aff8d2a79c9d97 ] Currently, data[5..7] of struct can_frame, when used as a CAN error frame, are defined as being "controller specific". Device specific behaviours are problematic because it prevents someone from writing code which is portable between devices. As a matter of fact, data[5] is never used, data[6] is always used to report TX error counter and data[7] is always used to report RX error counter. can-utils also relies on this. This patch updates the comment in the uapi header to specify that data[5] is reserved (and thus should not be used) and that data[6..7] are used for error counters. Fixes: 0d66548a10cb ("[CAN]: Add PF_CAN core module") Link: https://lore.kernel.org/all/20220719143550.3681-11-mailhol.vincent@wanadoo.f... Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- include/uapi/linux/can/error.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/can/error.h b/include/uapi/linux/can/error.h index bfc4b5d22a5e..383f3d508a53 100644 --- a/include/uapi/linux/can/error.h +++ b/include/uapi/linux/can/error.h @@ -120,6 +120,9 @@ #define CAN_ERR_TRX_CANL_SHORT_TO_GND 0x70 /* 0111 0000 */ #define CAN_ERR_TRX_CANL_SHORT_TO_CANH 0x80 /* 1000 0000 */ -/* controller specific additional information / data[5..7] */ +/* data[5] is reserved (do not use) */ + +/* TX error counter / data[6] */ +/* RX error counter / data[7] */ #endif /* _UAPI_CAN_ERROR_H */ -- 2.25.1