| Message ID | 20220915105046.2404072-4-vladimir.oltean@nxp.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9af23657b33679b5b8d8579ca1cc0214398f576f |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Small tc-taprio improvements | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/fixes_present | success | Fixes tag not required for -next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Series has a cover letter |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 2 this patch: 0 |
| netdev/cc_maintainers | success | CCed 9 of 9 maintainers |
| netdev/build_clang | success | Errors and warnings before: 0 this patch: 0 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | No Fixes tag |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 2 this patch: 0 |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 25 lines checked |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 63cbf856894a..6113c6646559 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1636,6 +1636,7 @@ static void taprio_destroy(struct Qdisc *sch) { struct taprio_sched *q = qdisc_priv(sch); struct net_device *dev = qdisc_dev(sch); + struct sched_gate_list *oper, *admin; unsigned int i; spin_lock(&taprio_list_lock); @@ -1659,11 +1660,14 @@ static void taprio_destroy(struct Qdisc *sch) netdev_reset_tc(dev); - if (q->oper_sched) - call_rcu(&q->oper_sched->rcu, taprio_free_sched_cb); + oper = rtnl_dereference(q->oper_sched); + admin = rtnl_dereference(q->admin_sched); + + if (oper) + call_rcu(&oper->rcu, taprio_free_sched_cb); - if (q->admin_sched) - call_rcu(&q->admin_sched->rcu, taprio_free_sched_cb); + if (admin) + call_rcu(&admin->rcu, taprio_free_sched_cb); } static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
Sparse complains that taprio_destroy() dereferences q->oper_sched and q->admin_sched without rcu_dereference(), since they are marked as __rcu in the taprio private structure. 1671:28: warning: incorrect type in argument 1 (different address spaces) 1671:28: expected struct callback_head *head 1671:28: got struct callback_head [noderef] __rcu * 1674:28: warning: incorrect type in argument 1 (different address spaces) 1674:28: expected struct callback_head *head 1674:28: got struct callback_head [noderef] __rcu * To silence that build warning, do actually use rtnl_dereference(), since we know the rtnl_mutex is held at the time of q->destroy(). Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> --- v1->v2: resend to net-next, use rtnl_dereference() instead of opening an rcu_read_lock() net/sched/sch_taprio.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)