[PATCH 4.4 001/146] mac80211: fix fast_tx header alignment

Greg Kroah-Hartman
2016-07-25T20:57:08Z

From: Felix Fietkau <nbd@nbd.name>

commit 6fe04128f158c5ad27e7504bfdf1b12e63331bc9 upstream.

The header field is defined as u8[] but also accessed as struct
ieee80211_hdr. Enforce an alignment of 2 to prevent unnecessary
unaligned accesses, which can be very harmful for performance on many
platforms.

Fixes: e495c24731a2 ("mac80211: extend fast-xmit for more ciphers")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/mac80211/sta_info.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -269,7 +269,7 @@ struct ieee80211_fast_tx {
u8 sa_offs, da_offs, pn_offs;
u8 band;
u8 hdr[30 + 2 + IEEE80211_FAST_XMIT_MAX_IV +
- sizeof(rfc1042_header)];
+ sizeof(rfc1042_header)] __aligned(2);

struct rcu_head rcu_head;
};