Re: [net-next PATCH 2/3] net: sched: cls_u32 add missing rcu_assign_pointer and annotation
flat view
From: John Fastabend <hidden>
Date: 2014-09-16 06:25:48
On 09/15/2014 07:48 PM, John Fastabend wrote:
quoted hunk ↗ jump to hunk
Add missing rcu_assign_pointer and missing annotation for ht_up in cls_u32.c Caught by kbuild bot,quoted
quoted
net/sched/cls_u32.c:378:36: sparse: incorrect type in initializer (different address spaces)net/sched/cls_u32.c:378:36: expected struct tc_u_hnode *ht net/sched/cls_u32.c:378:36: got struct tc_u_hnode [noderef] <asn:4>*ht_upquoted
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net/sched/cls_u32.c:610:54: sparse: incorrect type in argument 4 (different address spaces)net/sched/cls_u32.c:610:54: expected struct tc_u_hnode *ht net/sched/cls_u32.c:610:54: got struct tc_u_hnode [noderef] <asn:4>*ht_upquoted
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net/sched/cls_u32.c:684:18: sparse: incorrect type in assignment (different address spaces)net/sched/cls_u32.c:684:18: expected struct tc_u_hnode [noderef] <asn:4>*ht_up net/sched/cls_u32.c:684:18: got struct tc_u_hnode *[assigned] htquoted
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net/sched/cls_u32.c:359:18: sparse: dereference of noderef expressionSigned-off-by: John Fastabend <redacted> --- net/sched/cls_u32.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 8cffe5a..19b2808 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c@@ -375,7 +375,7 @@ static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key) { struct tc_u_knode __rcu **kp; struct tc_u_knode *pkp; - struct tc_u_hnode *ht = key->ht_up; + struct tc_u_hnode *ht = rtnl_dereference(key->ht_up); if (ht) { kp = &ht->ht[TC_U32_HASH(key->handle)];@@ -607,7 +607,8 @@ static int u32_change(struct net *net, struct sk_buff *in_skb, if (TC_U32_KEY(n->handle) == 0) return -EINVAL; - return u32_set_parms(net, tp, base, n->ht_up, n, tb, + return u32_set_parms(net, tp, base, + rtnl_dereference(n->ht_up), n, tb, tca[TCA_RATE], ovr); }@@ -681,7 +682,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb, #endif memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key)); - n->ht_up = ht; + rcu_assign_pointer(n->ht_up, ht);
also believe this should be RCU_INIT_POINTER() the rcu_assign_pointer() to attach n to the hash table happens below so there are no concurrent readers until after the assign. however while reviewing this I realize there is a 'copy'/'update' pattern I missed in the u32_set_parms case when the classid and ifindex is changed. So a fix coming for that shortly.
n->handle = handle; n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0; tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE); -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html