From: Johannes Berg <johannes.berg@xxxxxxxxx>
If drivers want to support S/G (really just gather DMA on TX) then
we can now easily support this on the fast-xmit path since it just
needs to write to the ethernet header (and already has a check for
that being possible.)
However, disallow this on the regular TX path (which has to handle
fragmentation, software crypto, etc.) by calling skb_linearize().
Also allow the related HIGHDMA since that's not interesting to the
code in mac80211 at all anyway.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 3 ++-
net/mac80211/tx.c | 6 ++++++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 3f837fea05ae..25a456c48043 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -86,7 +86,8 @@ struct ieee80211_local;
/* Only these features can be passed through mac80211 */
#define IEEE80211_SUPPORTED_NETDEV_FEATURES \
(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | \
- NETIF_F_HW_CSUM | NETIF_F_RXCSUM)
+ NETIF_F_HW_CSUM | NETIF_F_RXCSUM | \
+ NETIF_F_SG | NETIF_F_HIGHDMA)
struct ieee80211_fragment_entry {
unsigned long first_frag_time;
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index e76f3e96eb84..53a16257dfc1 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2848,6 +2848,12 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
goto out;
}
+ /* we cannot process non-linear frames on this path */
+ if (skb_linearize(skb)) {
+ kfree_skb(skb);
+ goto out;
+ }
+
/* the frame could be fragmented, software-encrypted, and other things
* so we cannot really handle checksum offload with it - fix it up in
* software before we handle anything else.
--
2.1.4
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