From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 19 May 2016 15:34:38 +0000 (+0200)
Subject: mac80211: fix fast_tx header alignment
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6fe04128f158c5ad27e7504bfdf1b12e63331bc9;p=linux-beck.git

mac80211: fix fast_tx header alignment

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")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index c8b8ccc370eb..78b0ef32dddd 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -280,7 +280,7 @@ 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;
 };