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authorVladimir Oltean <vladimir.oltean@nxp.com>2023-04-11 21:01:53 +0300
committerJakub Kicinski <kuba@kernel.org>2023-04-13 22:22:10 -0700
commitc54876cd5961ce0f8e74807f79a6739cd6b35ddf (patch)
treea61014a9e76680e63a7fd02cc925041d38d2a38b /net/sched
parentab277d2084ba59956b177a7d417791a27361e283 (diff)
net/sched: pass netlink extack to mqprio and taprio offload
With the multiplexed ndo_setup_tc() model which lacks a first-class struct netlink_ext_ack * argument, the only way to pass the netlink extended ACK message down to the device driver is to embed it within the offload structure. Do this for struct tc_mqprio_qopt_offload and struct tc_taprio_qopt_offload. Since struct tc_taprio_qopt_offload also contains a tc_mqprio_qopt_offload structure, and since device drivers might effectively reuse their mqprio implementation for the mqprio portion of taprio, we make taprio set the extack in both offload structures to point at the same netlink extack message. In fact, the taprio handling is a bit more tricky, for 2 reasons. First is because the offload structure has a longer lifetime than the extack structure. The driver is supposed to populate the extack synchronously from ndo_setup_tc() and leave it alone afterwards. To not have any use-after-free surprises, we zero out the extack pointer when we leave taprio_enable_offload(). The second reason is because taprio does overwrite the extack message on ndo_setup_tc() error. We need to switch to the weak form of setting an extack message, which preserves a potential message set by the driver. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_mqprio.c5
-rw-r--r--net/sched/sch_taprio.c12
2 files changed, 14 insertions, 3 deletions
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index aae4d64dbf3f..67d77495c8fd 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -33,9 +33,12 @@ static int mqprio_enable_offload(struct Qdisc *sch,
const struct tc_mqprio_qopt *qopt,
struct netlink_ext_ack *extack)
{
- struct tc_mqprio_qopt_offload mqprio = {.qopt = *qopt};
struct mqprio_sched *priv = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
+ struct tc_mqprio_qopt_offload mqprio = {
+ .qopt = *qopt,
+ .extack = extack,
+ };
int err, i;
switch (priv->mode) {
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 1f469861eae3..cbad43019172 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1520,7 +1520,9 @@ static int taprio_enable_offload(struct net_device *dev,
return -ENOMEM;
}
offload->enable = 1;
+ offload->extack = extack;
mqprio_qopt_reconstruct(dev, &offload->mqprio.qopt);
+ offload->mqprio.extack = extack;
taprio_sched_to_offload(dev, sched, offload, &caps);
for (tc = 0; tc < TC_MAX_QUEUE; tc++)
@@ -1528,14 +1530,20 @@ static int taprio_enable_offload(struct net_device *dev,
err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
if (err < 0) {
- NL_SET_ERR_MSG(extack,
- "Device failed to setup taprio offload");
+ NL_SET_ERR_MSG_WEAK(extack,
+ "Device failed to setup taprio offload");
goto done;
}
q->offloaded = true;
done:
+ /* The offload structure may linger around via a reference taken by the
+ * device driver, so clear up the netlink extack pointer so that the
+ * driver isn't tempted to dereference data which stopped being valid
+ */
+ offload->extack = NULL;
+ offload->mqprio.extack = NULL;
taprio_offload_free(offload);
return err;