net: sched: rcu'ify cls_bpf
This patch makes the cls_bpf classifier RCU safe. The tcf_lock was being used to protect a list of cls_bpf_prog now this list is RCU safe and updates occur with rcu_replace. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>hifive-unleashed-5.1
John Fastabend
David S. Miller
parent
b929d86d25
commit
1f947bf151
|
|
@ -27,6 +27,7 @@ MODULE_DESCRIPTION("TC BPF based classifier");
|
|||
struct cls_bpf_head {
|
||||
struct list_head plist;
|
||||
u32 hgen;
|
||||
struct rcu_head rcu;
|
||||
};
|
||||
|
||||
struct cls_bpf_prog {
|
||||
|
|
@ -37,6 +38,8 @@ struct cls_bpf_prog {
|
|||
struct list_head link;
|
||||
u32 handle;
|
||||
u16 bpf_len;
|
||||
struct tcf_proto *tp;
|
||||
struct rcu_head rcu;
|
||||
};
|
||||
|
||||
static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
|
||||
|
|
@ -49,11 +52,11 @@ static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
|
|||
static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
|
||||
struct tcf_result *res)
|
||||
{
|
||||
struct cls_bpf_head *head = tp->root;
|
||||
struct cls_bpf_head *head = rcu_dereference(tp->root);
|
||||
struct cls_bpf_prog *prog;
|
||||
int ret;
|
||||
|
||||
list_for_each_entry(prog, &head->plist, link) {
|
||||
list_for_each_entry_rcu(prog, &head->plist, link) {
|
||||
int filter_res = BPF_PROG_RUN(prog->filter, skb);
|
||||
|
||||
if (filter_res == 0)
|
||||
|
|
@ -81,8 +84,8 @@ static int cls_bpf_init(struct tcf_proto *tp)
|
|||
if (head == NULL)
|
||||
return -ENOBUFS;
|
||||
|
||||
INIT_LIST_HEAD(&head->plist);
|
||||
tp->root = head;
|
||||
INIT_LIST_HEAD_RCU(&head->plist);
|
||||
rcu_assign_pointer(tp->root, head);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -98,18 +101,22 @@ static void cls_bpf_delete_prog(struct tcf_proto *tp, struct cls_bpf_prog *prog)
|
|||
kfree(prog);
|
||||
}
|
||||
|
||||
static void __cls_bpf_delete_prog(struct rcu_head *rcu)
|
||||
{
|
||||
struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
|
||||
|
||||
cls_bpf_delete_prog(prog->tp, prog);
|
||||
}
|
||||
|
||||
static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
|
||||
{
|
||||
struct cls_bpf_head *head = tp->root;
|
||||
struct cls_bpf_head *head = rtnl_dereference(tp->root);
|
||||
struct cls_bpf_prog *prog, *todel = (struct cls_bpf_prog *) arg;
|
||||
|
||||
list_for_each_entry(prog, &head->plist, link) {
|
||||
if (prog == todel) {
|
||||
tcf_tree_lock(tp);
|
||||
list_del(&prog->link);
|
||||
tcf_tree_unlock(tp);
|
||||
|
||||
cls_bpf_delete_prog(tp, prog);
|
||||
list_del_rcu(&prog->link);
|
||||
call_rcu(&prog->rcu, __cls_bpf_delete_prog);
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
|
@ -119,27 +126,28 @@ static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
|
|||
|
||||
static void cls_bpf_destroy(struct tcf_proto *tp)
|
||||
{
|
||||
struct cls_bpf_head *head = tp->root;
|
||||
struct cls_bpf_head *head = rtnl_dereference(tp->root);
|
||||
struct cls_bpf_prog *prog, *tmp;
|
||||
|
||||
list_for_each_entry_safe(prog, tmp, &head->plist, link) {
|
||||
list_del(&prog->link);
|
||||
cls_bpf_delete_prog(tp, prog);
|
||||
list_del_rcu(&prog->link);
|
||||
call_rcu(&prog->rcu, __cls_bpf_delete_prog);
|
||||
}
|
||||
|
||||
kfree(head);
|
||||
RCU_INIT_POINTER(tp->root, NULL);
|
||||
kfree_rcu(head, rcu);
|
||||
}
|
||||
|
||||
static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
|
||||
{
|
||||
struct cls_bpf_head *head = tp->root;
|
||||
struct cls_bpf_head *head = rtnl_dereference(tp->root);
|
||||
struct cls_bpf_prog *prog;
|
||||
unsigned long ret = 0UL;
|
||||
|
||||
if (head == NULL)
|
||||
return 0UL;
|
||||
|
||||
list_for_each_entry(prog, &head->plist, link) {
|
||||
list_for_each_entry_rcu(prog, &head->plist, link) {
|
||||
if (prog->handle == handle) {
|
||||
ret = (unsigned long) prog;
|
||||
break;
|
||||
|
|
@ -158,10 +166,10 @@ static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,
|
|||
unsigned long base, struct nlattr **tb,
|
||||
struct nlattr *est, bool ovr)
|
||||
{
|
||||
struct sock_filter *bpf_ops, *bpf_old;
|
||||
struct sock_filter *bpf_ops;
|
||||
struct tcf_exts exts;
|
||||
struct sock_fprog_kern tmp;
|
||||
struct bpf_prog *fp, *fp_old;
|
||||
struct bpf_prog *fp;
|
||||
u16 bpf_size, bpf_len;
|
||||
u32 classid;
|
||||
int ret;
|
||||
|
|
@ -197,26 +205,15 @@ static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,
|
|||
if (ret)
|
||||
goto errout_free;
|
||||
|
||||
tcf_tree_lock(tp);
|
||||
fp_old = prog->filter;
|
||||
bpf_old = prog->bpf_ops;
|
||||
|
||||
prog->bpf_len = bpf_len;
|
||||
prog->bpf_ops = bpf_ops;
|
||||
prog->filter = fp;
|
||||
prog->res.classid = classid;
|
||||
tcf_tree_unlock(tp);
|
||||
|
||||
tcf_bind_filter(tp, &prog->res, base);
|
||||
tcf_exts_change(tp, &prog->exts, &exts);
|
||||
|
||||
if (fp_old)
|
||||
bpf_prog_destroy(fp_old);
|
||||
if (bpf_old)
|
||||
kfree(bpf_old);
|
||||
|
||||
return 0;
|
||||
|
||||
errout_free:
|
||||
kfree(bpf_ops);
|
||||
errout:
|
||||
|
|
@ -244,9 +241,10 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
|
|||
u32 handle, struct nlattr **tca,
|
||||
unsigned long *arg, bool ovr)
|
||||
{
|
||||
struct cls_bpf_head *head = tp->root;
|
||||
struct cls_bpf_prog *prog = (struct cls_bpf_prog *) *arg;
|
||||
struct cls_bpf_head *head = rtnl_dereference(tp->root);
|
||||
struct cls_bpf_prog *oldprog = (struct cls_bpf_prog *) *arg;
|
||||
struct nlattr *tb[TCA_BPF_MAX + 1];
|
||||
struct cls_bpf_prog *prog;
|
||||
int ret;
|
||||
|
||||
if (tca[TCA_OPTIONS] == NULL)
|
||||
|
|
@ -256,18 +254,19 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
|
|||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
if (prog != NULL) {
|
||||
if (handle && prog->handle != handle)
|
||||
return -EINVAL;
|
||||
return cls_bpf_modify_existing(net, tp, prog, base, tb,
|
||||
tca[TCA_RATE], ovr);
|
||||
}
|
||||
|
||||
prog = kzalloc(sizeof(*prog), GFP_KERNEL);
|
||||
if (prog == NULL)
|
||||
if (!prog)
|
||||
return -ENOBUFS;
|
||||
|
||||
tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
|
||||
|
||||
if (oldprog) {
|
||||
if (handle && oldprog->handle != handle) {
|
||||
ret = -EINVAL;
|
||||
goto errout;
|
||||
}
|
||||
}
|
||||
|
||||
if (handle == 0)
|
||||
prog->handle = cls_bpf_grab_new_handle(tp, head);
|
||||
else
|
||||
|
|
@ -281,16 +280,17 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
|
|||
if (ret < 0)
|
||||
goto errout;
|
||||
|
||||
tcf_tree_lock(tp);
|
||||
list_add(&prog->link, &head->plist);
|
||||
tcf_tree_unlock(tp);
|
||||
if (oldprog) {
|
||||
list_replace_rcu(&prog->link, &oldprog->link);
|
||||
call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
|
||||
} else {
|
||||
list_add_rcu(&prog->link, &head->plist);
|
||||
}
|
||||
|
||||
*arg = (unsigned long) prog;
|
||||
|
||||
return 0;
|
||||
errout:
|
||||
if (*arg == 0UL && prog)
|
||||
kfree(prog);
|
||||
kfree(prog);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
|
@ -339,10 +339,10 @@ nla_put_failure:
|
|||
|
||||
static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
|
||||
{
|
||||
struct cls_bpf_head *head = tp->root;
|
||||
struct cls_bpf_head *head = rtnl_dereference(tp->root);
|
||||
struct cls_bpf_prog *prog;
|
||||
|
||||
list_for_each_entry(prog, &head->plist, link) {
|
||||
list_for_each_entry_rcu(prog, &head->plist, link) {
|
||||
if (arg->count < arg->skip)
|
||||
goto skip;
|
||||
if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
|
||||
|
|
|
|||
Loading…
Reference in New Issue