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| author |   Vincent Mailhol <mailhol.vincent@wanadoo.fr> | 2021-12-14 01:02:24 +0900 |
|---|---|---|
| committer |   Marc Kleine-Budde <mkl@pengutronix.de> | 2022-01-05 12:09:05 +0100 |
| commit | 7d4a101c0bd3c6e5c6e45c705a54f7bc8f6c128d (patch) | |
| tree | bf77ce3f94c4ef2687d4418e78bdf094ec573506 /include/linux/can | |
| parent | can: dev: replace can_priv::ctrlmode_static by can_get_static_ctrlmode() (diff) | |
| download | linux-dev-7d4a101c0bd3c6e5c6e45c705a54f7bc8f6c128d.tar.xz linux-dev-7d4a101c0bd3c6e5c6e45c705a54f7bc8f6c128d.zip | |
can: dev: add sanity check in can_set_static_ctrlmode()
Previous patch removed can_priv::ctrlmode_static to replace it with
can_get_static_ctrlmode().
A condition sine qua non for this to work is that the controller
static modes should never be set in can_priv::ctrlmode_supported
(c.f. the comment on can_priv::ctrlmode_supported which states that it
is for "options that can be *modified* by netlink"). Also, this
condition is already correctly fulfilled by all existing drivers
which rely on the ctrlmode_static feature.
Nonetheless, we added an extra safeguard in can_set_static_ctrlmode()
to return an error value and to warn the developer who would be
adventurous enough to set to static a given feature that is already
set to supported.
The drivers which rely on the static controller mode are then updated
to check the return value of can_set_static_ctrlmode().
Link: https://lore.kernel.org/all/20211213160226.56219-3-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'include/linux/can')
| -rw-r--r-- | include/linux/can/dev.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index 92e2d69462f0..fff3f70df697 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -131,17 +131,24 @@ static inline s32 can_get_relative_tdco(const struct can_priv *priv) } /* helper to define static CAN controller features at device creation time */ -static inline void can_set_static_ctrlmode(struct net_device *dev, - u32 static_mode) +static inline int __must_check can_set_static_ctrlmode(struct net_device *dev, + u32 static_mode) { struct can_priv *priv = netdev_priv(dev); /* alloc_candev() succeeded => netdev_priv() is valid at this point */ + if (priv->ctrlmode_supported & static_mode) { + netdev_warn(dev, + "Controller features can not be supported and static at the same time\n"); + return -EINVAL; + } priv->ctrlmode = static_mode; /* override MTU which was set by default in can_setup()? */ if (static_mode & CAN_CTRLMODE_FD) dev->mtu = CANFD_MTU; + + return 0; } static inline u32 can_get_static_ctrlmode(struct can_priv *priv) |