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-rw-r--r--net/core/skmsg.c87
1 files changed, 74 insertions, 13 deletions
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 654182ecf87b..25cdbb20f3a0 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -170,10 +170,12 @@ static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
struct scatterlist *sge = sk_msg_elem(msg, i);
u32 len = sge->length;
- if (charge)
- sk_mem_uncharge(sk, len);
- if (!msg->skb)
+ /* When the skb owns the memory we free it from consume_skb path. */
+ if (!msg->skb) {
+ if (charge)
+ sk_mem_uncharge(sk, len);
put_page(sg_page(sge));
+ }
memset(sge, 0, sizeof(*sge));
return len;
}
@@ -397,28 +399,45 @@ out:
}
EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
-static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
+static struct sk_msg *sk_psock_create_ingress_msg(struct sock *sk,
+ struct sk_buff *skb)
{
- struct sock *sk = psock->sk;
- int copied = 0, num_sge;
struct sk_msg *msg;
+ if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
+ return NULL;
+
+ if (!sk_rmem_schedule(sk, skb, skb->truesize))
+ return NULL;
+
msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
if (unlikely(!msg))
- return -EAGAIN;
- if (!sk_rmem_schedule(sk, skb, skb->len)) {
- kfree(msg);
- return -EAGAIN;
- }
+ return NULL;
sk_msg_init(msg);
+ return msg;
+}
+
+static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb,
+ struct sk_psock *psock,
+ struct sock *sk,
+ struct sk_msg *msg)
+{
+ int num_sge, copied;
+
+ /* skb linearize may fail with ENOMEM, but lets simply try again
+ * later if this happens. Under memory pressure we don't want to
+ * drop the skb. We need to linearize the skb so that the mapping
+ * in skb_to_sgvec can not error.
+ */
+ if (skb_linearize(skb))
+ return -EAGAIN;
num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len);
if (unlikely(num_sge < 0)) {
kfree(msg);
return num_sge;
}
- sk_mem_charge(sk, skb->len);
copied = skb->len;
msg->sg.start = 0;
msg->sg.size = copied;
@@ -430,6 +449,48 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
return copied;
}
+static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb);
+
+static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
+{
+ struct sock *sk = psock->sk;
+ struct sk_msg *msg;
+
+ /* If we are receiving on the same sock skb->sk is already assigned,
+ * skip memory accounting and owner transition seeing it already set
+ * correctly.
+ */
+ if (unlikely(skb->sk == sk))
+ return sk_psock_skb_ingress_self(psock, skb);
+ msg = sk_psock_create_ingress_msg(sk, skb);
+ if (!msg)
+ return -EAGAIN;
+
+ /* This will transition ownership of the data from the socket where
+ * the BPF program was run initiating the redirect to the socket
+ * we will eventually receive this data on. The data will be released
+ * from skb_consume found in __tcp_bpf_recvmsg() after its been copied
+ * into user buffers.
+ */
+ skb_set_owner_r(skb, sk);
+ return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
+}
+
+/* Puts an skb on the ingress queue of the socket already assigned to the
+ * skb. In this case we do not need to check memory limits or skb_set_owner_r
+ * because the skb is already accounted for here.
+ */
+static int sk_psock_skb_ingress_self(struct sk_psock *psock, struct sk_buff *skb)
+{
+ struct sk_msg *msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
+ struct sock *sk = psock->sk;
+
+ if (unlikely(!msg))
+ return -EAGAIN;
+ sk_msg_init(msg);
+ return sk_psock_skb_ingress_enqueue(skb, psock, sk, msg);
+}
+
static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
u32 off, u32 len, bool ingress)
{
@@ -789,7 +850,7 @@ static void sk_psock_verdict_apply(struct sk_psock *psock,
* retrying later from workqueue.
*/
if (skb_queue_empty(&psock->ingress_skb)) {
- err = sk_psock_skb_ingress(psock, skb);
+ err = sk_psock_skb_ingress_self(psock, skb);
}
if (err < 0) {
skb_queue_tail(&psock->ingress_skb, skb);