From: Vlad Buslov <vladbu@mellanox.com>
Date: Fri, 10 Aug 2018 20:51:41 +0300
Subject: net: sched: act_bpf: remove dependency on rtnl lock
Patch-mainline: v4.19-rc1
Git-commit: 2142236b45843dbcbe9691d24cf06caff91a78fd
References: bsc#1109837
Use tcf spinlock to protect bpf action private data from concurrent
modification during dump and init. Remove rtnl lock assertion that is no
longer necessary.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
net/sched/act_bpf.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/net/sched/act_bpf.c
+++ b/net/sched/act_bpf.c
@@ -143,11 +143,12 @@ static int tcf_bpf_dump(struct sk_buff *
.index = prog->tcf_index,
.refcnt = refcount_read(&prog->tcf_refcnt) - ref,
.bindcnt = atomic_read(&prog->tcf_bindcnt) - bind,
- .action = prog->tcf_action,
};
struct tcf_t tm;
int ret;
+ spin_lock(&prog->tcf_lock);
+ opt.action = prog->tcf_action;
if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
@@ -163,9 +164,11 @@ static int tcf_bpf_dump(struct sk_buff *
TCA_ACT_BPF_PAD))
goto nla_put_failure;
+ spin_unlock(&prog->tcf_lock);
return skb->len;
nla_put_failure:
+ spin_unlock(&prog->tcf_lock);
nlmsg_trim(skb, tp);
return -1;
}
@@ -264,7 +267,7 @@ static void tcf_bpf_prog_fill_cfg(const
{
cfg->is_ebpf = tcf_bpf_is_ebpf(prog);
/* updates to prog->filter are prevented, since it's called either
- * with rtnl lock or during final cleanup in rcu callback
+ * with tcf lock or during final cleanup in rcu callback
*/
cfg->filter = rcu_dereference_protected(prog->filter, 1);
@@ -336,8 +339,8 @@ static int tcf_bpf_init(struct net *net,
goto out;
prog = to_bpf(*act);
- ASSERT_RTNL();
+ spin_lock(&prog->tcf_lock);
if (res != ACT_P_CREATED)
tcf_bpf_prog_fill_cfg(prog, &old);
@@ -349,6 +352,7 @@ static int tcf_bpf_init(struct net *net,
prog->tcf_action = parm->action;
rcu_assign_pointer(prog->filter, cfg.filter);
+ spin_unlock(&prog->tcf_lock);
if (res == ACT_P_CREATED) {
tcf_idr_insert(tn, *act);