Merge branch 'uprobes-v7' of git://git.linaro.org/people/dave.long/linux into devel-stable

This patch series adds basic uprobes support to ARM. It is based on
patches developed earlier by Rabin Vincent. That approach of adding
hooks into the kprobes instruction parsing code was not well received.
This approach separates the ARM instruction parsing code in kprobes out
into a separate set of functions which can be used by both kprobes and
uprobes. Both kprobes and uprobes then provide their own semantic action
tables to process the results of the parsing.

1 files changed, 17 insertions, 65 deletions

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 5ae609200674..f558433537b8 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1367,44 +1367,35 @@ static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
 	return false;
 }
 
-/* Increase asoc's rwnd by len and send any window update SACK if needed. */
-void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
+/* Update asoc's rwnd for the approximated state in the buffer,
+ * and check whether SACK needs to be sent.
+ */
+void sctp_assoc_rwnd_update(struct sctp_association *asoc, bool update_peer)
 {
+	int rx_count;
 	struct sctp_chunk *sack;
 	struct timer_list *timer;
 
-	if (asoc->rwnd_over) {
-		if (asoc->rwnd_over >= len) {
-			asoc->rwnd_over -= len;
-		} else {
-			asoc->rwnd += (len - asoc->rwnd_over);
-			asoc->rwnd_over = 0;
-		}
-	} else {
-		asoc->rwnd += len;
-	}
+	if (asoc->ep->rcvbuf_policy)
+		rx_count = atomic_read(&asoc->rmem_alloc);
+	else
+		rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
 
-	/* If we had window pressure, start recovering it
-	 * once our rwnd had reached the accumulated pressure
-	 * threshold.  The idea is to recover slowly, but up
-	 * to the initial advertised window.
-	 */
-	if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) {
-		int change = min(asoc->pathmtu, asoc->rwnd_press);
-		asoc->rwnd += change;
-		asoc->rwnd_press -= change;
-	}
+	if ((asoc->base.sk->sk_rcvbuf - rx_count) > 0)
+		asoc->rwnd = (asoc->base.sk->sk_rcvbuf - rx_count) >> 1;
+	else
+		asoc->rwnd = 0;
 
-	pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
-		 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
-		 asoc->a_rwnd);
+	pr_debug("%s: asoc:%p rwnd=%u, rx_count=%d, sk_rcvbuf=%d\n",
+		 __func__, asoc, asoc->rwnd, rx_count,
+		 asoc->base.sk->sk_rcvbuf);
 
 	/* Send a window update SACK if the rwnd has increased by at least the
 	 * minimum of the association's PMTU and half of the receive buffer.
 	 * The algorithm used is similar to the one described in
 	 * Section 4.2.3.3 of RFC 1122.
 	 */
-	if (sctp_peer_needs_update(asoc)) {
+	if (update_peer && sctp_peer_needs_update(asoc)) {
 		asoc->a_rwnd = asoc->rwnd;
 
 		pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
@@ -1426,45 +1417,6 @@ void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
 	}
 }
 
-/* Decrease asoc's rwnd by len. */
-void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
-{
-	int rx_count;
-	int over = 0;
-
-	if (unlikely(!asoc->rwnd || asoc->rwnd_over))
-		pr_debug("%s: association:%p has asoc->rwnd:%u, "
-			 "asoc->rwnd_over:%u!\n", __func__, asoc,
-			 asoc->rwnd, asoc->rwnd_over);
-
-	if (asoc->ep->rcvbuf_policy)
-		rx_count = atomic_read(&asoc->rmem_alloc);
-	else
-		rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
-
-	/* If we've reached or overflowed our receive buffer, announce
-	 * a 0 rwnd if rwnd would still be positive.  Store the
-	 * the potential pressure overflow so that the window can be restored
-	 * back to original value.
-	 */
-	if (rx_count >= asoc->base.sk->sk_rcvbuf)
-		over = 1;
-
-	if (asoc->rwnd >= len) {
-		asoc->rwnd -= len;
-		if (over) {
-			asoc->rwnd_press += asoc->rwnd;
-			asoc->rwnd = 0;
-		}
-	} else {
-		asoc->rwnd_over = len - asoc->rwnd;
-		asoc->rwnd = 0;
-	}
-
-	pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
-		 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
-		 asoc->rwnd_press);
-}
 
 /* Build the bind address list for the association based on info from the
  * local endpoint and the remote peer.