[PATCH 4.0 099/148] mac80211: dont use napi_gro_receive() outside NAPI context

Greg Kroah-Hartman
2015-06-03T12:44:47Z

From: Johannes Berg <johannes.berg@intel.com>

commit 22d3a3c829fa9ecdb493d1f1f2838d543f8d86a3 upstream.

No matter how the driver manages its NAPI context, there's no way
sending frames to it from a timer can be correct, since it would
corrupt the internal GRO lists.

To avoid that, always use the non-NAPI path when releasing frames
from the timer.

Reported-by: Jean Trivelly <jean.trivelly@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/mac80211/ieee80211_i.h | 3 +++
net/mac80211/rx.c | 5 +++--
2 files changed, 6 insertions(+), 2 deletions(-)

--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -204,6 +204,8 @@ enum ieee80211_packet_rx_flags {
* @IEEE80211_RX_CMNTR: received on cooked monitor already
* @IEEE80211_RX_BEACON_REPORTED: This frame was already reported
* to cfg80211_report_obss_beacon().
+ * @IEEE80211_RX_REORDER_TIMER: this frame is released by the
+ * reorder buffer timeout timer, not the normal RX path
*
* These flags are used across handling multiple interfaces
* for a single frame.
@@ -211,6 +213,7 @@ enum ieee80211_packet_rx_flags {
enum ieee80211_rx_flags {
IEEE80211_RX_CMNTR = BIT(0),
IEEE80211_RX_BEACON_REPORTED = BIT(1),
+ IEEE80211_RX_REORDER_TIMER = BIT(2),
};

struct ieee80211_rx_data {
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2106,7 +2106,8 @@ ieee80211_deliver_skb(struct ieee80211_r
/* deliver to local stack */
skb->protocol = eth_type_trans(skb, dev);
memset(skb->cb, 0, sizeof(skb->cb));
- if (rx->local->napi)
+ if (!(rx->flags & IEEE80211_RX_REORDER_TIMER) &&
+ rx->local->napi)
napi_gro_receive(rx->local->napi, skb);
else
netif_receive_skb(skb);
@@ -3215,7 +3216,7 @@ void ieee80211_release_reorder_timeout(s
/* This is OK -- must be QoS data frame */
.security_idx = tid,
.seqno_idx = tid,
- .flags = 0,
+ .flags = IEEE80211_RX_REORDER_TIMER,
};
struct tid_ampdu_rx *tid_agg_rx;