diff options
| author | Pedro Tammela <pctammela@mojatatu.com> | 2023-07-28 12:35:33 -0300 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2023-08-01 10:47:24 +0200 |
| commit | 8798481b667fa7c9bbd5aa843bf1557ada699964 (patch) | |
| tree | 164b3ceb99342adfe3cfa8da837947ccfa784704 /net/sched/sch_htb.c | |
| parent | 05e1d8bdb276068069d3de65e488700280029e20 (diff) | |
net/sched: wrap open coded Qdics class filter counter
The 'filter_cnt' counter is used to control a Qdisc class lifetime.
Each filter referecing this class by its id will eventually
increment/decrement this counter in their respective
'add/update/delete' routines.
As these operations are always serialized under rtnl lock, we don't
need an atomic type like 'refcount_t'.
It also means that we lose the overflow/underflow checks already
present in refcount_t, which are valuable to hunt down bugs
where the unsigned counter wraps around as it aids automated tools
like syzkaller to scream in such situations.
Wrap the open coded increment/decrement into helper functions and
add overflow checks to the operations.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/sched/sch_htb.c')
| -rw-r--r-- | net/sched/sch_htb.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 333800a7d4eb..05c8291865ae 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -102,7 +102,6 @@ struct htb_class { struct tcf_proto __rcu *filter_list; /* class attached filters */ struct tcf_block *block; - int filter_cnt; int level; /* our level (see above) */ unsigned int children; @@ -1710,7 +1709,7 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg, * tc subsys guarantee us that in htb_destroy it holds no class * refs so that we can remove children safely there ? */ - if (cl->children || cl->filter_cnt) + if (cl->children || qdisc_class_in_use(&cl->common)) return -EBUSY; if (!cl->level && htb_parent_last_child(cl)) @@ -2107,7 +2106,7 @@ static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent, * be broken by class during destroy IIUC. */ if (cl) - cl->filter_cnt++; + qdisc_class_get(&cl->common); return (unsigned long)cl; } @@ -2115,8 +2114,7 @@ static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg) { struct htb_class *cl = (struct htb_class *)arg; - if (cl) - cl->filter_cnt--; + qdisc_class_put(&cl->common); } static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg) |