Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 63 insertions, 16 deletions

diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index a00e5f81156..c630a21b2be 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -82,6 +82,7 @@ static struct sk_buff *tipc_disc_init_msg(u32 type,
 		msg = buf_msg(buf);
 		tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain);
 		msg_set_non_seq(msg, 1);
+		msg_set_node_sig(msg, tipc_random);
 		msg_set_dest_domain(msg, dest_domain);
 		msg_set_bc_netid(msg, tipc_net_id);
 		b_ptr->media->addr2msg(&b_ptr->addr, msg_media_addr(msg));
@@ -121,20 +122,22 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 {
 	struct tipc_node *n_ptr;
 	struct tipc_link *link;
-	struct tipc_media_addr media_addr, *addr;
+	struct tipc_media_addr media_addr;
 	struct sk_buff *rbuf;
 	struct tipc_msg *msg = buf_msg(buf);
 	u32 dest = msg_dest_domain(msg);
 	u32 orig = msg_prevnode(msg);
 	u32 net_id = msg_bc_netid(msg);
 	u32 type = msg_type(msg);
+	u32 signature = msg_node_sig(msg);
+	int addr_mismatch;
 	int link_fully_up;
 
 	media_addr.broadcast = 1;
 	b_ptr->media->msg2addr(&media_addr, msg_media_addr(msg));
-	buf_discard(buf);
+	kfree_skb(buf);
 
-	/* Validate discovery message from requesting node */
+	/* Ensure message from node is valid and communication is permitted */
 	if (net_id != tipc_net_id)
 		return;
 	if (media_addr.broadcast)
@@ -162,15 +165,50 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 	}
 	tipc_node_lock(n_ptr);
 
+	/* Prepare to validate requesting node's signature and media address */
 	link = n_ptr->links[b_ptr->identity];
+	addr_mismatch = (link != NULL) &&
+		memcmp(&link->media_addr, &media_addr, sizeof(media_addr));
 
-	/* Create a link endpoint for this bearer, if necessary */
-	if (!link) {
-		link = tipc_link_create(n_ptr, b_ptr, &media_addr);
-		if (!link) {
+	/*
+	 * Ensure discovery message's signature is correct
+	 *
+	 * If signature is incorrect and there is no working link to the node,
+	 * accept the new signature but invalidate all existing links to the
+	 * node so they won't re-activate without a new discovery message.
+	 *
+	 * If signature is incorrect and the requested link to the node is
+	 * working, accept the new signature. (This is an instance of delayed
+	 * rediscovery, where a link endpoint was able to re-establish contact
+	 * with its peer endpoint on a node that rebooted before receiving a
+	 * discovery message from that node.)
+	 *
+	 * If signature is incorrect and there is a working link to the node
+	 * that is not the requested link, reject the request (must be from
+	 * a duplicate node).
+	 */
+	if (signature != n_ptr->signature) {
+		if (n_ptr->working_links == 0) {
+			struct tipc_link *curr_link;
+			int i;
+
+			for (i = 0; i < MAX_BEARERS; i++) {
+				curr_link = n_ptr->links[i];
+				if (curr_link) {
+					memset(&curr_link->media_addr, 0,
+					       sizeof(media_addr));
+					tipc_link_reset(curr_link);
+				}
+			}
+			addr_mismatch = (link != NULL);
+		} else if (tipc_link_is_up(link) && !addr_mismatch) {
+			/* delayed rediscovery */
+		} else {
+			disc_dupl_alert(b_ptr, orig, &media_addr);
 			tipc_node_unlock(n_ptr);
 			return;
 		}
+		n_ptr->signature = signature;
 	}
 
 	/*
@@ -183,17 +221,26 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 	 * the new media address and reset the link to ensure it starts up
 	 * cleanly.
 	 */
-	addr = &link->media_addr;
-	if (memcmp(addr, &media_addr, sizeof(*addr))) {
-		if (tipc_link_is_up(link) || (!link->started)) {
+
+	if (addr_mismatch) {
+		if (tipc_link_is_up(link)) {
 			disc_dupl_alert(b_ptr, orig, &media_addr);
 			tipc_node_unlock(n_ptr);
 			return;
+		} else {
+			memcpy(&link->media_addr, &media_addr,
+			       sizeof(media_addr));
+			tipc_link_reset(link);
+		}
+	}
+
+	/* Create a link endpoint for this bearer, if necessary */
+	if (!link) {
+		link = tipc_link_create(n_ptr, b_ptr, &media_addr);
+		if (!link) {
+			tipc_node_unlock(n_ptr);
+			return;
 		}
-		warn("Resetting link <%s>, peer interface address changed\n",
-		     link->name);
-		memcpy(addr, &media_addr, sizeof(*addr));
-		tipc_link_reset(link);
 	}
 
 	/* Accept discovery message & send response, if necessary */
@@ -203,7 +250,7 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 		rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr);
 		if (rbuf) {
 			b_ptr->media->send_msg(rbuf, b_ptr, &media_addr);
-			buf_discard(rbuf);
+			kfree_skb(rbuf);
 		}
 	}
 
@@ -349,7 +396,7 @@ void tipc_disc_delete(struct tipc_link_req *req)
 {
 	k_cancel_timer(&req->timer);
 	k_term_timer(&req->timer);
-	buf_discard(req->buf);
+	kfree_skb(req->buf);
 	kfree(req);
 }