Commit 1616b38f authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
Browse files

kcm: Fix locking issue 



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: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cff6a334

net/kcm/kcmproc.c

+15 −5
Original line number Diff line number Diff line
@@ -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->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");

}

net/kcm/kcmsock.c

+8 −5
Original line number Diff line number Diff line
@@ -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))

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