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authorPaolo Abeni <pabeni@redhat.com>2018-02-02 16:02:22 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-12 07:07:21 +0100
commitce6fa12a7ba5f685ab6a5833f5d5c04b3da25df5 (patch)
tree3b6c8df11ff6e8038bfa0a6c322cd864669c173d
parenta742a89695ce06f064406ab6fcd64110b12b9917 (diff)
download96b-common-ce6fa12a7ba5f685ab6a5833f5d5c04b3da25df5.tar.gz
cls_u32: add missing RCU annotation.
[ Upstream commit 058a6c033488494a6b1477b05fe8e1a16e344462 ] 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: a1b7c5fd7fe9 ("net: sched: add cls_u32 offload hooks for netdevs") Fixes: de5df63228fc ("net: sched: cls_u32 changes to knode must appear atomic to readers") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/sched/cls_u32.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 507859cdd1cb..33294b5b2c6a 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -544,6 +544,7 @@ static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
u32 flags)
{
+ 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);
@@ -563,7 +564,7 @@ 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) {
@@ -840,8 +841,9 @@ 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);
@@ -859,11 +861,11 @@ 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