| Message ID | 20160821032534.11074-1-linus.luessing@c0d3.blue |
|---|---|
| State | Superseded, archived |
| Delegated to: | Marek Lindner |
| Headers | show |
On Sonntag, 21. August 2016 05:25:32 CEST Linus Lüssing wrote: [...] > @@ -334,8 +333,9 @@ int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface) > goto out; > > skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN); > - elp_buff = skb_push(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN); > - elp_packet = (struct batadv_elp_packet *)elp_buff; > + skb_put(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN); > + elp_packet = (struct batadv_elp_packet *) > + hard_iface->bat_v.elp_skb->data; > memset(elp_packet, 0, BATADV_ELP_HLEN); > > elp_packet->packet_type = BATADV_ELP; > I don't get right now why you did the of split the skb_put into two different "ugly" lines (skb_put + the elp_packet assignment without elp_buff). I fear that this weird (non)-alignment you've created will bite us when the patch is submitted upstream. Maybe you can tell us more about why this removal of elp_buff is necessary. Btw. please use the prefix "batman-adv" in the subject and not "batamn-adv" ;) And it is at the moment not important whether it goes into next or maint. Both will be submitted by Simon to net.git because we are currently completely off with our timing (compared to the upstream submissions). I personally would go for maint. Kind regards, Sven
diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index df42eb1..ea463bf 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -323,7 +323,6 @@ out: int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface) { struct batadv_elp_packet *elp_packet; - unsigned char *elp_buff; u32 random_seqno; size_t size; int res = -ENOMEM; @@ -334,8 +333,9 @@ int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface) goto out; skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN); - elp_buff = skb_push(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN); - elp_packet = (struct batadv_elp_packet *)elp_buff; + skb_put(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN); + elp_packet = (struct batadv_elp_packet *) + hard_iface->bat_v.elp_skb->data; memset(elp_packet, 0, BATADV_ELP_HLEN); elp_packet->packet_type = BATADV_ELP;
The skb_reserve() call only reserved headroom for the mac header, but not the elp packet header itself. Fixing this by using skb_put()'ing towards the skb tail instead of skb_push()'ing towards the skb head. Fixes: a4b88af77e28 ("batman-adv: ELP - adding basic infrastructure") Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> --- Looking at some tests today, we might have been lucky so far: dev_alloc_skb(size = 32) seems to actually round the head- and tailroom reservation to 64 bytes. So there actually is enough headroom for the skb_push(). Not sure whether this is always the case though, so unsure whether this should go to maint/stable. Also switching skb_push() with skb_pull() instead of simply increasing skb_reserve() by ELP_HLEN, because of the next patch in this series. --- net/batman-adv/bat_v_elp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)