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: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2016-08-23 11:55:31 -07:00 committed by David S. Miller
parent cff6a334e6
commit 1616b38f20
2 changed files with 23 additions and 10 deletions

View File

@ -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");
}

View File

@ -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))