On Wed, May 28, 2008 at 7:50 PM, Senthilkumar Balasubramanian <Senthilkumar.Balasubramanian@xxxxxxxxxxx> wrote: > ________________________________________ > From: John W. Linville [linville@xxxxxxxxxxxxx] > Sent: Wednesday, May 28, 2008 8:46 PM > To: Senthilkumar Balasubramanian > Cc: johannes@xxxxxxxxxxxxxxxx; ron.rindjunsky@xxxxxxxxx; linux-wireless@xxxxxxxxxxxxxxx; Luis Rodriguez > Subject: Re: [PATCH] mac80211: fix alignment issue with compare_ether_addr() > > On Wed, May 28, 2008 at 08:20:48PM +0530, Senthil Balasubramanian wrote: >> This addresses an alignment issue with compare_ether_addr(). >> The addresses passed to compare_ether_addr should be two bytes aligned. >> It may function properly in x86 platform. However may not work properly >> on IA-64 or ARM processor. > >> --- a/net/mac80211/rx.c >> +++ b/net/mac80211/rx.c >> @@ -1116,7 +1116,9 @@ ieee80211_data_to_8023(struct ieee80211_rx_data *rx) >> u16 fc, hdrlen, ethertype; >> u8 *payload; >> u8 dst[ETH_ALEN]; >> - u8 src[ETH_ALEN]; >> + /* Should be aligned on 2 bytes for compare_ether_addr() */ >> + u16 src_aligned[ETH_ALEN >> 1]; >> + u8 *src = (u8 *)src_aligned; >> struct sk_buff *skb = rx->skb; >> struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); >> DECLARE_MAC_BUF(mac); > > Any reason you couldn't just do this? > > I just thought of using the type u16 instead of attribute here. that's all. No specific reason. > > @@ -1116,7 +1116,7 @@ ieee80211_data_to_8023(struct ieee80211_rx_data *rx) > u16 fc, hdrlen, ethertype; > u8 *payload; > u8 dst[ETH_ALEN]; > - u8 src[ETH_ALEN]; > + u8 src[ETH_ALEN] __attribute__ ((aligned(2))); > struct sk_buff *skb = rx->skb; > struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); > DECLARE_MAC_BUF(mac); > > It seems to compile w/o errors on i686, and it seems more clear to me. > Will that not work? > > Yes. It should also work. I will re-create the patch and send it to you. I will also include Johannes suggestion of just using __aligned macro. > Can we split the two issues in seperate patches. It's better for tracking. Thanks Tomas -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
