diff mbox series

[net,4/9] wireguard: use synchronize_net rather than synchronize_rcu

Message ID 20210604151738.220232-5-Jason@zx2c4.com (mailing list archive)
State Accepted
Commit 24b70eeeb4f46c09487f8155239ebfb1f875774a
Delegated to: Netdev Maintainers
Headers show
Series wireguard fixes for 5.13-rc5 | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net
netdev/subject_prefix success Link
netdev/cc_maintainers warning 1 maintainers not CCed: wireguard@lists.zx2c4.com
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 32 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Jason A. Donenfeld June 4, 2021, 3:17 p.m. UTC
Many of the synchronization points are sometimes called under the rtnl
lock, which means we should use synchronize_net rather than
synchronize_rcu. Under the hood, this expands to using the expedited
flavor of function in the event that rtnl is held, in order to not stall
other concurrent changes.

This fixes some very, very long delays when removing multiple peers at
once, which would cause some operations to take several minutes.

Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Cc: stable@vger.kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 drivers/net/wireguard/peer.c   | 6 +++---
 drivers/net/wireguard/socket.c | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/wireguard/peer.c b/drivers/net/wireguard/peer.c
index cd5cb0292cb6..3a042d28eb2e 100644
--- a/drivers/net/wireguard/peer.c
+++ b/drivers/net/wireguard/peer.c
@@ -88,7 +88,7 @@  static void peer_make_dead(struct wg_peer *peer)
 	/* Mark as dead, so that we don't allow jumping contexts after. */
 	WRITE_ONCE(peer->is_dead, true);
 
-	/* The caller must now synchronize_rcu() for this to take effect. */
+	/* The caller must now synchronize_net() for this to take effect. */
 }
 
 static void peer_remove_after_dead(struct wg_peer *peer)
@@ -160,7 +160,7 @@  void wg_peer_remove(struct wg_peer *peer)
 	lockdep_assert_held(&peer->device->device_update_lock);
 
 	peer_make_dead(peer);
-	synchronize_rcu();
+	synchronize_net();
 	peer_remove_after_dead(peer);
 }
 
@@ -178,7 +178,7 @@  void wg_peer_remove_all(struct wg_device *wg)
 		peer_make_dead(peer);
 		list_add_tail(&peer->peer_list, &dead_peers);
 	}
-	synchronize_rcu();
+	synchronize_net();
 	list_for_each_entry_safe(peer, temp, &dead_peers, peer_list)
 		peer_remove_after_dead(peer);
 }
diff --git a/drivers/net/wireguard/socket.c b/drivers/net/wireguard/socket.c
index d9ad850daa79..8c496b747108 100644
--- a/drivers/net/wireguard/socket.c
+++ b/drivers/net/wireguard/socket.c
@@ -430,7 +430,7 @@  void wg_socket_reinit(struct wg_device *wg, struct sock *new4,
 	if (new4)
 		wg->incoming_port = ntohs(inet_sk(new4)->inet_sport);
 	mutex_unlock(&wg->socket_update_lock);
-	synchronize_rcu();
+	synchronize_net();
 	sock_free(old4);
 	sock_free(old6);
 }