From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Björn Töpel" <bjorn.topel@intel.com>,
"Jesper Dangaard Brouer" <brouer@redhat.com>,
"Song Liu" <songliubraving@fb.com>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Sasha Levin" <sashal@kernel.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 135/209] xsk: proper AF_XDP socket teardown ordering
Date: Tue, 12 Nov 2019 20:49:11 -0500 [thread overview]
Message-ID: <20191113015025.9685-135-sashal@kernel.org> (raw)
In-Reply-To: <20191113015025.9685-1-sashal@kernel.org>
From: Björn Töpel <bjorn.topel@intel.com>
[ Upstream commit 541d7fdd7694560404c502f64298a90ffe017e6b ]
The AF_XDP socket struct can exist in three different, implicit
states: setup, bound and released. Setup is prior the socket has been
bound to a device. Bound is when the socket is active for receive and
send. Released is when the process/userspace side of the socket is
released, but the sock object is still lingering, e.g. when there is a
reference to the socket in an XSKMAP after process termination.
The Rx fast-path code uses the "dev" member of struct xdp_sock to
check whether a socket is bound or relased, and the Tx code uses the
struct xdp_umem "xsk_list" member in conjunction with "dev" to
determine the state of a socket.
However, the transition from bound to released did not tear the socket
down in correct order.
On the Rx side "dev" was cleared after synchronize_net() making the
synchronization useless. On the Tx side, the internal queues were
destroyed prior removing them from the "xsk_list".
This commit corrects the cleanup order, and by doing so
xdp_del_sk_umem() can be simplified and one synchronize_net() can be
removed.
Fixes: 965a99098443 ("xsk: add support for bind for Rx")
Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions")
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/xdp/xdp_umem.c | 11 +++--------
net/xdp/xsk.c | 13 ++++++++-----
2 files changed, 11 insertions(+), 13 deletions(-)
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 8cab91c482ff5..d9117ab035f7c 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -32,14 +32,9 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
{
unsigned long flags;
- if (xs->dev) {
- spin_lock_irqsave(&umem->xsk_list_lock, flags);
- list_del_rcu(&xs->list);
- spin_unlock_irqrestore(&umem->xsk_list_lock, flags);
-
- if (umem->zc)
- synchronize_net();
- }
+ spin_lock_irqsave(&umem->xsk_list_lock, flags);
+ list_del_rcu(&xs->list);
+ spin_unlock_irqrestore(&umem->xsk_list_lock, flags);
}
int xdp_umem_query(struct net_device *dev, u16 queue_id)
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 661504042d304..ff15207036dc5 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -343,12 +343,18 @@ static int xsk_release(struct socket *sock)
local_bh_enable();
if (xs->dev) {
+ struct net_device *dev = xs->dev;
+
/* Wait for driver to stop using the xdp socket. */
- synchronize_net();
- dev_put(xs->dev);
+ xdp_del_sk_umem(xs->umem, xs);
xs->dev = NULL;
+ synchronize_net();
+ dev_put(dev);
}
+ xskq_destroy(xs->rx);
+ xskq_destroy(xs->tx);
+
sock_orphan(sk);
sock->sk = NULL;
@@ -707,9 +713,6 @@ static void xsk_destruct(struct sock *sk)
if (!sock_flag(sk, SOCK_DEAD))
return;
- xskq_destroy(xs->rx);
- xskq_destroy(xs->tx);
- xdp_del_sk_umem(xs->umem, xs);
xdp_put_umem(xs->umem);
sk_refcnt_debug_dec(sk);
--
2.20.1
next prev parent reply other threads:[~2019-11-13 2:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191113015025.9685-1-sashal@kernel.org>
2019-11-13 1:48 ` [PATCH AUTOSEL 4.19 068/209] ixgbe: Fix ixgbe TX hangs with XDP_TX beyond queue limit Sasha Levin
2019-11-13 1:49 ` [PATCH AUTOSEL 4.19 124/209] tc-testing: fix build of eBPF programs Sasha Levin
2019-11-13 1:49 ` Sasha Levin [this message]
2019-11-13 1:49 ` [PATCH AUTOSEL 4.19 177/209] bpf: btf: Fix a missing check bug Sasha Levin
2019-11-13 1:49 ` [PATCH AUTOSEL 4.19 178/209] net: fix generic XDP to handle if eth header was mangled Sasha Levin
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