Check each bit timing parameter first individually against their limits and report a meaningful error message via netlink to the user space. In case of an error, return -EINVAL instead of -ERANGE, this corresponds better to the actual meaning of the error value. Link: https://lore.kernel.org/all/20230202110854.2318594-12-mkl@xxxxxxxxxxxxxx Suggested-by: Vincent Mailhol <vincent.mailhol@xxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/dev/bittiming.c | 38 +++++++++++++++++++++++++++------ 1 file changed, 31 insertions(+), 7 deletions(-) diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c index 101de1b3bf30..727dcd52cc2c 100644 --- a/drivers/net/can/dev/bittiming.c +++ b/drivers/net/can/dev/bittiming.c @@ -33,22 +33,38 @@ static int can_fixup_bittiming(const struct net_device *dev, struct can_bittimin const struct can_bittiming_const *btc, struct netlink_ext_ack *extack) { + const unsigned int tseg1 = bt->prop_seg + bt->phase_seg1; const struct can_priv *priv = netdev_priv(dev); - unsigned int tseg1; u64 brp64; int err; + if (tseg1 < btc->tseg1_min) { + NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u less than tseg1-min: %u", + tseg1, btc->tseg1_min); + return -EINVAL; + } + if (tseg1 > btc->tseg1_max) { + NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u greater than tseg1-max: %u", + tseg1, btc->tseg1_max); + return -EINVAL; + } + if (bt->phase_seg2 < btc->tseg2_min) { + NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u less than tseg2-min: %u", + bt->phase_seg2, btc->tseg2_min); + return -EINVAL; + } + if (bt->phase_seg2 > btc->tseg2_max) { + NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u greater than tseg2-max: %u", + bt->phase_seg2, btc->tseg2_max); + return -EINVAL; + } + can_sjw_set_default(bt); err = can_sjw_check(dev, bt, btc, extack); if (err) return err; - tseg1 = bt->prop_seg + bt->phase_seg1; - if (tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max || - bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max) - return -ERANGE; - brp64 = (u64)priv->clock.freq * (u64)bt->tq; if (btc->brp_inc > 1) do_div(brp64, btc->brp_inc); @@ -58,8 +74,16 @@ static int can_fixup_bittiming(const struct net_device *dev, struct can_bittimin brp64 *= btc->brp_inc; bt->brp = (u32)brp64; - if (bt->brp < btc->brp_min || bt->brp > btc->brp_max) + if (bt->brp < btc->brp_min) { + NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u less than brp-min: %u", + bt->brp, btc->brp_min); return -EINVAL; + } + if (bt->brp > btc->brp_max) { + NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u greater than brp-max: %u", + bt->brp, btc->brp_max); + return -EINVAL; + } bt->bitrate = priv->clock.freq / (bt->brp * can_bit_time(bt)); bt->sample_point = ((CAN_SYNC_SEG + tseg1) * 1000) / can_bit_time(bt); -- 2.39.1
