mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

skmsg: Introduce a spinlock to protect ingress_msg 

Currently we rely on lock_sock to protect ingress_msg,
it is too big for this, we can actually just use a spinlock
to protect this list like protecting other skb queues.

__tcp_bpf_recvmsg() is still special because of peeking,
it still has to use lock_sock.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210331023237.41094-3-xiyou.wangcong@gmail.com
This commit is contained in:
Cong Wang 2021-03-30 19:32:23 -07:00 committed by Alexei Starovoitov
parent 37f0e514db
commit b01fd6e802
3 changed files with 55 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

46
include/linux/skmsg.h
View File

@ -89,6 +89,7 @@ struct sk_psock {
#endif
struct sk_buff_head ingress_skb;
struct list_head ingress_msg;
spinlock_t ingress_lock;
unsigned long state;
struct list_head link;
spinlock_t link_lock;
@ -284,7 +285,45 @@ static inline struct sk_psock *sk_psock(const struct sock *sk)
static inline void sk_psock_queue_msg(struct sk_psock *psock,
struct sk_msg *msg)
{
spin_lock_bh(&psock->ingress_lock);
list_add_tail(&msg->list, &psock->ingress_msg);
spin_unlock_bh(&psock->ingress_lock);
}
static inline struct sk_msg *sk_psock_dequeue_msg(struct sk_psock *psock)
{
struct sk_msg *msg;
spin_lock_bh(&psock->ingress_lock);
msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
if (msg)
list_del(&msg->list);
spin_unlock_bh(&psock->ingress_lock);
return msg;
}
static inline struct sk_msg *sk_psock_peek_msg(struct sk_psock *psock)
{
struct sk_msg *msg;
spin_lock_bh(&psock->ingress_lock);
msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
spin_unlock_bh(&psock->ingress_lock);
return msg;
}
static inline struct sk_msg *sk_psock_next_msg(struct sk_psock *psock,
struct sk_msg *msg)
{
struct sk_msg *ret;
spin_lock_bh(&psock->ingress_lock);
if (list_is_last(&msg->list, &psock->ingress_msg))
ret = NULL;
else
ret = list_next_entry(msg, list);
spin_unlock_bh(&psock->ingress_lock);
return ret;
}
static inline bool sk_psock_queue_empty(const struct sk_psock *psock)
@ -292,6 +331,13 @@ static inline bool sk_psock_queue_empty(const struct sk_psock *psock)
return psock ? list_empty(&psock->ingress_msg) : true;
}
static inline void kfree_sk_msg(struct sk_msg *msg)
{
if (msg->skb)
consume_skb(msg->skb);
kfree(msg);
}
static inline void sk_psock_report_error(struct sk_psock *psock, int err)
{
struct sock *sk = psock->sk;

3
net/core/skmsg.c
View File

@ -592,6 +592,7 @@ struct sk_psock *sk_psock_init(struct sock *sk, int node)
INIT_WORK(&psock->work, sk_psock_backlog);
INIT_LIST_HEAD(&psock->ingress_msg);
spin_lock_init(&psock->ingress_lock);
skb_queue_head_init(&psock->ingress_skb);
sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED);
@ -638,7 +639,9 @@ static void sk_psock_zap_ingress(struct sk_psock *psock)
skb_bpf_redirect_clear(skb);
kfree_skb(skb);
}
spin_lock_bh(&psock->ingress_lock);
__sk_psock_purge_ingress_msg(psock);
spin_unlock_bh(&psock->ingress_lock);
}
static void sk_psock_link_destroy(struct sk_psock *psock)

18
net/ipv4/tcp_bpf.c
View File

@ -18,9 +18,7 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
struct sk_msg *msg_rx;
int i, copied = 0;
msg_rx = list_first_entry_or_null(&psock->ingress_msg,
struct sk_msg, list);
msg_rx = sk_psock_peek_msg(psock);
while (copied != len) {
struct scatterlist *sge;
@ -68,22 +66,18 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
} while (i != msg_rx->sg.end);
if (unlikely(peek)) {
if (msg_rx == list_last_entry(&psock->ingress_msg,
struct sk_msg, list))
msg_rx = sk_psock_next_msg(psock, msg_rx);
if (!msg_rx)
break;
msg_rx = list_next_entry(msg_rx, list);
continue;
}
msg_rx->sg.start = i;
if (!sge->length && msg_rx->sg.start == msg_rx->sg.end) {
list_del(&msg_rx->list);
if (msg_rx->skb)
consume_skb(msg_rx->skb);
kfree(msg_rx);
msg_rx = sk_psock_dequeue_msg(psock);
kfree_sk_msg(msg_rx);
}
msg_rx = list_first_entry_or_null(&psock->ingress_msg,
struct sk_msg, list);
msg_rx = sk_psock_peek_msg(psock);
}
return copied;