From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>, Wei Liu <wei.liu@kernel.org>,
Paul Durrant <paul@xen.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Igor Druzhinin <igor.druzhinin@citrix.com>,
stable@vger.kernel.org
Subject: [PATCH] xen/netback: avoid race in xenvif_rx_ring_slots_available()
Date: Tue, 2 Feb 2021 08:09:38 +0100 [thread overview]
Message-ID: <20210202070938.7863-1-jgross@suse.com> (raw)
Since commit 23025393dbeb3b8b3 ("xen/netback: use lateeoi irq binding")
xenvif_rx_ring_slots_available() is no longer called only from the rx
queue kernel thread, so it needs to access the rx queue with the
associated queue held.
Reported-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Fixes: 23025393dbeb3b8b3 ("xen/netback: use lateeoi irq binding")
Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/net/xen-netback/rx.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
index b8febe1d1bfd..accc991d153f 100644
--- a/drivers/net/xen-netback/rx.c
+++ b/drivers/net/xen-netback/rx.c
@@ -38,10 +38,15 @@ static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
RING_IDX prod, cons;
struct sk_buff *skb;
int needed;
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->rx_queue.lock, flags);
skb = skb_peek(&queue->rx_queue);
- if (!skb)
+ if (!skb) {
+ spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
return false;
+ }
needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);
if (skb_is_gso(skb))
@@ -49,6 +54,8 @@ static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
if (skb->sw_hash)
needed++;
+ spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
+
do {
prod = queue->rx.sring->req_prod;
cons = queue->rx.req_cons;
--
2.26.2
next reply other threads:[~2021-02-02 7:10 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 7:09 Juergen Gross [this message]
2021-02-02 15:26 ` [PATCH] xen/netback: avoid race in xenvif_rx_ring_slots_available() Igor Druzhinin
2021-02-02 16:12 ` Jürgen Groß
2021-02-02 16:22 ` Wei Liu
2021-02-03 23:48 ` Jakub Kicinski
2021-02-04 5:32 ` Jürgen Groß
2021-02-05 1:56 ` Jakub Kicinski
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