[PATCH net-next 0/2] strp: Minor fixes to strparser and kcm

[PATCH net-next 0/2] strp: Minor fixes to strparser and kcm

[Tom Herbert]

Fix locking issue in kcm and losing events when paused.

Tom Herbert (2):
  strparser: Queue work when being unpaused
  kcm: Fix locking issue

 include/net/strparser.h   |  5 +----
 net/kcm/kcmproc.c         | 20 +++++++++++++++-----
 net/kcm/kcmsock.c         | 13 ++++++++-----
 net/strparser/strparser.c | 11 +++++++++++
 4 files changed, 35 insertions(+), 14 deletions(-)

-- 
2.8.0.rc2

[PATCH net-next 1/2] strparser: Queue work when being unpaused

[Tom Herbert]

When the upper layer unpauses a stream parser connection we need to
queue rx_work to make sure no events are missed.

Signed-off-by: Tom Herbert <tom@herbertland.com>
---
 include/net/strparser.h   |  5 +----
 net/strparser/strparser.c | 11 +++++++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/net/strparser.h b/include/net/strparser.h
index fdb3d67..91fa0b9 100644
--- a/include/net/strparser.h
+++ b/include/net/strparser.h
@@ -88,10 +88,7 @@ static inline void strp_pause(struct strparser *strp)
 }
 
 /* May be called without holding lock for attached socket */
-static inline void strp_unpause(struct strparser *strp)
-{
-	strp->rx_paused = 0;
-}
+void strp_unpause(struct strparser *strp);
 
 static inline void save_strp_stats(struct strparser *strp,
 				   struct strp_aggr_stats *agg_stats)
diff --git a/net/strparser/strparser.c b/net/strparser/strparser.c
index 68334b5..4ecfc10 100644
--- a/net/strparser/strparser.c
+++ b/net/strparser/strparser.c
@@ -445,6 +445,17 @@ int strp_init(struct strparser *strp, struct sock *csk,
 }
 EXPORT_SYMBOL_GPL(strp_init);
 
+void strp_unpause(struct strparser *strp)
+{
+	strp->rx_paused = 0;
+
+	/* Sync setting rx_paused with RX work */
+	smp_mb();
+
+	queue_work(strp_wq, &strp->rx_work);
+}
+EXPORT_SYMBOL_GPL(strp_unpause);
+
 /* strp must already be stopped so that strp_tcp_recv will no longer be called.
  * Note that strp_done is not called with the lower socket held.
  */
-- 
2.8.0.rc2

[PATCH net-next 2/2] kcm: Fix locking issue

[Tom Herbert]

Lock the lower socket in kcm_unattach. Release during call to strp_done
since that function cancels the RX timers and work queue with sync.

Also added some status information in psock reporting.

Signed-off-by: Tom Herbert <tom@herbertland.com>
---
 net/kcm/kcmproc.c | 20 +++++++++++++++-----
 net/kcm/kcmsock.c | 13 ++++++++-----
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/net/kcm/kcmproc.c b/net/kcm/kcmproc.c
index 47e4453..bf75c92 100644
--- a/net/kcm/kcmproc.c
+++ b/net/kcm/kcmproc.c
@@ -173,14 +173,24 @@ static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
 	if (psock->strp.rx_stopped)
 		seq_puts(seq, "RxStop ");
 
-	if (psock->strp.rx_paused)
-		seq_puts(seq, "RxPause ");
-
 	if (psock->tx_kcm)
 		seq_printf(seq, "Rsvd-%d ", psock->tx_kcm->index);
 
-	if (psock->ready_rx_msg)
-		seq_puts(seq, "RdyRx ");
+	if (!psock->strp.rx_paused && !psock->ready_rx_msg) {
+		if (psock->sk->sk_receive_queue.qlen) {
+			if (psock->strp.rx_need_bytes)
+				seq_printf(seq, "RxWait=%u ",
+					   psock->strp.rx_need_bytes);
+			else
+				seq_printf(seq, "RxWait ");
+		}
+	} else  {
+		if (psock->strp.rx_paused)
+			seq_puts(seq, "RxPause ");
+
+		if (psock->ready_rx_msg)
+			seq_puts(seq, "RdyRx ");
+	}
 
 	seq_puts(seq, "\n");
 }
diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index eedbe40..eb731ca 100644
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -1477,12 +1477,13 @@ out:
 	return err;
 }
 
-/* Lower socket lock held */
 static void kcm_unattach(struct kcm_psock *psock)
 {
 	struct sock *csk = psock->sk;
 	struct kcm_mux *mux = psock->mux;
 
+	lock_sock(csk);
+
 	/* Stop getting callbacks from TCP socket. After this there should
 	 * be no way to reserve a kcm for this psock.
 	 */
@@ -1514,7 +1515,10 @@ static void kcm_unattach(struct kcm_psock *psock)
 
 	write_unlock_bh(&csk->sk_callback_lock);
 
+	/* Call strp_done without sock lock */
+	release_sock(csk);
 	strp_done(&psock->strp);
+	lock_sock(csk);
 
 	bpf_prog_put(psock->bpf_prog);
 
@@ -1564,6 +1568,8 @@ no_reserved:
 		fput(csk->sk_socket->file);
 		kmem_cache_free(kcm_psockp, psock);
 	}
+
+	release_sock(csk);
 }
 
 static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info)
@@ -1749,11 +1755,8 @@ static void release_mux(struct kcm_mux *mux)
 	/* Release psocks */
 	list_for_each_entry_safe(psock, tmp_psock,
 				 &mux->psocks, psock_list) {
-		if (!WARN_ON(psock->unattaching)) {
-			lock_sock(psock->strp.sk);
+		if (!WARN_ON(psock->unattaching))
 			kcm_unattach(psock);
-			release_sock(psock->strp.sk);
-		}
 	}
 
 	if (WARN_ON(mux->psocks_cnt))
-- 
2.8.0.rc2

Re: [PATCH net-next 0/2] strp: Minor fixes to strparser and kcm

[David Miller]

From: Tom Herbert <tom@herbertland.com>
Date: Tue, 23 Aug 2016 11:55:29 -0700

> Fix locking issue in kcm and losing events when paused.

Series applied, thanks Tom.