Commit 058a6c03 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

cls_u32: add missing RCU annotation. 



In a couple of points of the control path, n->ht_down is currently
accessed without the required RCU annotation. The accesses are
safe, but sparse complaints. Since we already held the
rtnl lock, let use rtnl_dereference().

Fixes: a1b7c5fd ("net: sched: add cls_u32 offload hooks for netdevs")
Fixes: de5df632 ("net: sched: cls_u32 changes to knode must appear atomic to readers")
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Acked-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0072f0c4

net/sched/cls_u32.c

+7 −5
Original line number Diff line number Diff line
@@ -548,6 +548,7 @@ static void u32_remove_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n, 
static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,

				u32 flags, struct netlink_ext_ack *extack)

{

	struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);

	struct tcf_block *block = tp->chain->block;

	struct tc_cls_u32_offload cls_u32 = {};

	bool skip_sw = tc_skip_sw(flags);
@@ -567,7 +568,7 @@ static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n, 
	cls_u32.knode.sel = &n->sel;

	cls_u32.knode.exts = &n->exts;

	if (n->ht_down)

		cls_u32.knode.link_handle = n->ht_down->handle;

		cls_u32.knode.link_handle = ht->handle;



	err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSU32, &cls_u32, skip_sw);

	if (err < 0) {
@@ -855,8 +856,9 @@ static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c, 
static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,

					 struct tc_u_knode *n)

{

	struct tc_u_knode *new;

	struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);

	struct tc_u32_sel *s = &n->sel;

	struct tc_u_knode *new;



	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),

		      GFP_KERNEL);
@@ -874,11 +876,11 @@ static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp, 
	new->fshift = n->fshift;

	new->res = n->res;

	new->flags = n->flags;

	RCU_INIT_POINTER(new->ht_down, n->ht_down);

	RCU_INIT_POINTER(new->ht_down, ht);



	/* bump reference count as long as we hold pointer to structure */

	if (new->ht_down)

		new->ht_down->refcnt++;

	if (ht)

		ht->refcnt++;



#ifdef CONFIG_CLS_U32_PERF

	/* Statistics may be incremented by readers during update

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