[SK_BUFF]: Convert skb->tail to sk_buff_data_t

So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)

Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.

Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

arch/ia64/sn/kernel/xpnet.c

···
 
 	dev_dbg(xpnet, "<skb->head=0x%p skb->data=0x%p skb->tail=0x%p "
 		"skb->end=0x%p skb->len=%d\n", (void *) skb->head,
-		(void *) skb->data, (void *) skb->tail, (void *) skb->end,
+		(void *)skb->data, skb_tail_pointer(skb), (void *)skb->end,
 		skb->len);
 
 	skb->protocol = eth_type_trans(skb, xpnet_device);
···
 
 	dev_dbg(xpnet, "passing skb to network layer; \n\tskb->head=0x%p "
 		"skb->data=0x%p skb->tail=0x%p skb->end=0x%p skb->len=%d\n",
-		(void *) skb->head, (void *) skb->data, (void *) skb->tail,
+		(void *)skb->head, (void *)skb->data, skb_tail_pointer(skb),
 		(void *) skb->end, skb->len);
 
 
···
 
 	dev_dbg(xpnet, ">skb->head=0x%p skb->data=0x%p skb->tail=0x%p "
 		"skb->end=0x%p skb->len=%d\n", (void *) skb->head,
-		(void *) skb->data, (void *) skb->tail, (void *) skb->end,
+		(void *)skb->data, skb_tail_pointer(skb), (void *)skb->end,
 		skb->len);
 
 
···
 
 	/* get the beginning of the first cacheline and end of last */
 	start_addr = ((u64) skb->data & ~(L1_CACHE_BYTES - 1));
-	end_addr = L1_CACHE_ALIGN((u64) skb->tail);
+	end_addr = L1_CACHE_ALIGN((u64)skb_tail_pointer(skb));
 
 	/* calculate how many bytes to embed in the XPC message */
 	embedded_bytes = 0;
···
 		msg->magic = XPNET_MAGIC;
 		msg->size = end_addr - start_addr;
 		msg->leadin_ignore = (u64) skb->data - start_addr;
-		msg->tailout_ignore = end_addr - (u64) skb->tail;
+		msg->tailout_ignore = end_addr - (u64)skb_tail_pointer(skb);
 		msg->buf_pa = __pa(start_addr);
 
 		dev_dbg(xpnet, "sending XPC message to %d:%d\nmsg->buf_pa="

drivers/atm/he.c

···
 			case ATM_AAL0:
 				/* 2.10.1.5 raw cell receive */
 				skb->len = ATM_AAL0_SDU;
-				skb->tail = skb->data + skb->len;
+				skb_set_tail_pointer(skb, skb->len);
 				break;
 			case ATM_AAL5:
 				/* 2.10.1.2 aal5 receive */
 
 				skb->len = AAL5_LEN(skb->data, he_vcc->pdu_len);
-				skb->tail = skb->data + skb->len;
+				skb_set_tail_pointer(skb, skb->len);
 #ifdef USE_CHECKSUM_HW
 				if (vcc->vpi == 0 && vcc->vci >= ATM_NOT_RSV_VCI) {
 					skb->ip_summed = CHECKSUM_COMPLETE;

drivers/atm/idt77252.c

···
 	u32 handle;
 	u32 addr;
 
-	skb->data = skb->tail = skb->head;
+	skb->data = skb->head;
+	skb_reset_tail_pointer(skb);
 	skb->len = 0;
 
 	skb_reserve(skb, 16);

drivers/atm/nicstar.c

···
          if (i == 1 && ns_rsqe_eopdu(rsqe))
             *((u32 *) sb->data) |= 0x00000002;
          skb_put(sb, NS_AAL0_HEADER);
-         memcpy(sb->tail, cell, ATM_CELL_PAYLOAD);
+         memcpy(skb_tail_pointer(sb), cell, ATM_CELL_PAYLOAD);
          skb_put(sb, ATM_CELL_PAYLOAD);
          ATM_SKB(sb)->vcc = vcc;
 	 __net_timestamp(sb);
···
       vc->rx_iov = iovb;
       NS_SKB(iovb)->iovcnt = 0;
       iovb->len = 0;
-      iovb->tail = iovb->data = iovb->head;
+      iovb->data = iovb->head;
+      skb_reset_tail_pointer(iovb);
       NS_SKB(iovb)->vcc = vcc;
       /* IMPORTANT: a pointer to the sk_buff containing the small or large
                     buffer is stored as iovec base, NOT a pointer to the 
···
       recycle_iovec_rx_bufs(card, (struct iovec *) iovb->data, NS_MAX_IOVECS);
       NS_SKB(iovb)->iovcnt = 0;
       iovb->len = 0;
-      iovb->tail = iovb->data = iovb->head;
+      iovb->data = iovb->head;
+      skb_reset_tail_pointer(iovb);
       NS_SKB(iovb)->vcc = vcc;
    }
    iov = &((struct iovec *) iovb->data)[NS_SKB(iovb)->iovcnt++];
···
             {
                lb = (struct sk_buff *) iov->iov_base;
                tocopy = min_t(int, remaining, iov->iov_len);
-               memcpy(hb->tail, lb->data, tocopy);
+               memcpy(skb_tail_pointer(hb), lb->data, tocopy);
                skb_put(hb, tocopy);
                iov++;
                remaining -= tocopy;

drivers/infiniband/hw/amso1100/c2.c

···
 	}
 
 	/* Setup the skb for reuse since we're dropping this pkt */
-	elem->skb->tail = elem->skb->data = elem->skb->head;
+	elem->skb->data = elem->skb->head;
+	skb_reset_tail_pointer(elem->skb);
 
 	/* Zero out the rxp hdr in the sk_buff */
 	memset(elem->skb->data, 0, sizeof(*rxp_hdr));
···
 		 * "sizeof(struct c2_rxp_hdr)".
 		 */
 		skb->data += sizeof(*rxp_hdr);
-		skb->tail = skb->data + buflen;
+		skb_set_tail_pointer(skb, buflen);
 		skb->len = buflen;
 		skb->protocol = eth_type_trans(skb, netdev);
 

drivers/isdn/i4l/isdn_net.c

···
 
 	addinfo[0] = '\0';
 	/* This check stolen from 2.1.72 dev_queue_xmit_nit() */
-	if (p < skb->data || p >= skb->tail) {
+	if (p < skb->data || skb->network_header >= skb->tail) {
 		/* fall back to old isdn_net_log_packet method() */
 		char * buf = skb->data;
 

drivers/media/dvb/dvb-core/dvb_net.c

···
 			/* Check CRC32, we've got it in our skb already. */
 			unsigned short ulen = htons(priv->ule_sndu_len);
 			unsigned short utype = htons(priv->ule_sndu_type);
+			const u8 *tail;
 			struct kvec iov[3] = {
 				{ &ulen, sizeof ulen },
 				{ &utype, sizeof utype },
···
 			}
 
 			ule_crc = iov_crc32(ule_crc, iov, 3);
-			expected_crc = *((u8 *)priv->ule_skb->tail - 4) << 24 |
-				       *((u8 *)priv->ule_skb->tail - 3) << 16 |
-				       *((u8 *)priv->ule_skb->tail - 2) << 8 |
-				       *((u8 *)priv->ule_skb->tail - 1);
+			tail = skb_tail_pointer(priv->ule_skb);
+			expected_crc = *(tail - 4) << 24 |
+				       *(tail - 3) << 16 |
+				       *(tail - 2) << 8 |
+				       *(tail - 1);
 			if (ule_crc != expected_crc) {
 				printk(KERN_WARNING "%lu: CRC32 check FAILED: %08x / %08x, SNDU len %d type %#x, ts_remain %d, next 2: %x.\n",
 				       priv->ts_count, ule_crc, expected_crc, priv->ule_sndu_len, priv->ule_sndu_type, ts_remain, ts_remain > 2 ? *(unsigned short *)from_where : 0);

drivers/net/cris/eth_v10.c

···
 
 #ifdef ETHDEBUG
 		printk("head = 0x%x, data = 0x%x, tail = 0x%x, end = 0x%x\n",
-		  skb->head, skb->data, skb->tail, skb->end);
+		  skb->head, skb->data, skb_tail_pointer(skb), skb->end);
 		printk("copying packet to 0x%x.\n", skb_data_ptr);
 #endif
 

drivers/net/cxgb3/sge.c

···
 	flits = skb_transport_offset(skb) / 8;
 	sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl;
 	sgl_flits = make_sgl(skb, sgp, skb_transport_header(skb),
-			     skb->tail - skb_transport_header(skb),
+			     skb->tail - skb->transport_header,
 			     adap->pdev);
 	if (need_skb_unmap()) {
 		setup_deferred_unmapping(skb, adap->pdev, sgp, sgl_flits);
 		skb->destructor = deferred_unmap_destructor;
 		((struct unmap_info *)skb->cb)->len = (skb->tail -
-						       skb_transport_header(skb));
+						       skb->transport_header);
 	}
 
 	write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits,
···
 		return 1;	/* packet fits as immediate data */
 
 	flits = skb_transport_offset(skb) / 8;	/* headers */
-	if (skb->tail != skb_transport_header(skb))
+	if (skb->tail != skb->transport_header)
 		cnt++;
 	return flits_to_desc(flits + sgl_len(cnt));
 }

drivers/net/e1000/e1000_main.c

···
 				 * NOTE: this is a TSO only workaround
 				 * if end byte alignment not correct move us
 				 * into the next dword */
-				if ((unsigned long)(skb->tail - 1) & 4)
+				if ((unsigned long)(skb_tail_pointer(skb) - 1) & 4)
 					break;
 				/* fall through */
 			case e1000_82571:
···
 				PCI_DMA_FROMDEVICE);
 			vaddr = kmap_atomic(ps_page->ps_page[0],
 			                    KM_SKB_DATA_SOFTIRQ);
-			memcpy(skb->tail, vaddr, l1);
+			memcpy(skb_tail_pointer(skb), vaddr, l1);
 			kunmap_atomic(vaddr, KM_SKB_DATA_SOFTIRQ);
 			pci_dma_sync_single_for_device(pdev,
 				ps_page_dma->ps_page_dma[0],

drivers/net/ibm_emac/ibm_emac_core.c

···
 			dev_kfree_skb(dev->rx_sg_skb);
 			dev->rx_sg_skb = NULL;
 		} else {
-			cacheable_memcpy(dev->rx_sg_skb->tail,
+			cacheable_memcpy(skb_tail_pointer(dev->rx_sg_skb),
 					 dev->rx_skb[slot]->data, len);
 			skb_put(dev->rx_sg_skb, len);
 			emac_recycle_rx_skb(dev, slot, len);

drivers/net/macb.c

···
 	int i;
 	dev_dbg(&bp->pdev->dev,
 		"start_xmit: len %u head %p data %p tail %p end %p\n",
-		skb->len, skb->head, skb->data, skb->tail, skb->end);
+		skb->len, skb->head, skb->data,
+		skb_tail_pointer(skb), skb->end);
 	dev_dbg(&bp->pdev->dev,
 		"data:");
 	for (i = 0; i < 16; i++)

drivers/net/pcmcia/nmclan_cs.c

···
 	skb_reserve(skb, 2);
 	insw(ioaddr + AM2150_RCV, skb_put(skb, pkt_len), pkt_len>>1);
 	if (pkt_len & 1)
-	    *(skb->tail-1) = inb(ioaddr + AM2150_RCV);
+	    *(skb_tail_pointer(skb) - 1) = inb(ioaddr + AM2150_RCV);
 	skb->protocol = eth_type_trans(skb, dev);
 	
 	netif_rx(skb); /* Send the packet to the upper (protocol) layers. */

drivers/net/s2io.c

···
 	frag_list->next = NULL;
 	tmp = (void *)ALIGN((long)frag_list->data, ALIGN_SIZE + 1);
 	frag_list->data = tmp;
-	frag_list->tail = tmp;
+	skb_reset_tail_pointer(frag_list);
 
 	/* Buffer-2 receives L4 data payload */
 	((struct RxD3*)rxdp)->Buffer2_ptr = pci_map_single(nic->pdev,
···
 			tmp += ALIGN_SIZE;
 			tmp &= ~ALIGN_SIZE;
 			skb->data = (void *) (unsigned long)tmp;
-			skb->tail = (void *) (unsigned long)tmp;
+			skb_reset_tail_pointer(skb);
 
 			if (!(((struct RxD3*)rxdp)->Buffer0_ptr))
 				((struct RxD3*)rxdp)->Buffer0_ptr =

drivers/net/tulip/uli526x.c

···
 					!= NULL) ) {
 					/* size less than COPY_SIZE, allocate a rxlen SKB */
 					skb_reserve(skb, 2); /* 16byte align */
-					memcpy(skb_put(skb, rxlen), rxptr->rx_skb_ptr->tail, rxlen);
+					memcpy(skb_put(skb, rxlen),
+					       skb_tail_pointer(rxptr->rx_skb_ptr),
+					       rxlen);
 					uli526x_reuse_skb(db, rxptr->rx_skb_ptr);
 				} else
 					skb_put(skb, rxlen);
···
 
 	if (!(rxptr->rdes0 & cpu_to_le32(0x80000000))) {
 		rxptr->rx_skb_ptr = skb;
-		rxptr->rdes2 = cpu_to_le32( pci_map_single(db->pdev, skb->tail, RX_ALLOC_SIZE, PCI_DMA_FROMDEVICE) );
+		rxptr->rdes2 = cpu_to_le32(pci_map_single(db->pdev,
+							  skb_tail_pointer(skb),
+							  RX_ALLOC_SIZE,
+							  PCI_DMA_FROMDEVICE));
 		wmb();
 		rxptr->rdes0 = cpu_to_le32(0x80000000);
 		db->rx_avail_cnt++;
···
 		if ( ( skb = dev_alloc_skb(RX_ALLOC_SIZE) ) == NULL )
 			break;
 		rxptr->rx_skb_ptr = skb; /* FIXME (?) */
-		rxptr->rdes2 = cpu_to_le32( pci_map_single(db->pdev, skb->tail, RX_ALLOC_SIZE, PCI_DMA_FROMDEVICE) );
+		rxptr->rdes2 = cpu_to_le32(pci_map_single(db->pdev,
+							  skb_tail_pointer(skb),
+							  RX_ALLOC_SIZE,
+							  PCI_DMA_FROMDEVICE));
 		wmb();
 		rxptr->rdes0 = cpu_to_le32(0x80000000);
 		rxptr = rxptr->next_rx_desc;

drivers/net/wan/hdlc_fr.c

···
 		skb->protocol = __constant_htons(NLPID_CCITT_ANSI_LMI);
 		fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
 	}
-	data = skb->tail;
+	data = skb_tail_pointer(skb);
 	data[i++] = LMI_CALLREF;
 	data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
 	if (lmi == LMI_ANSI)

drivers/net/wan/lmc/lmc_main.c

···
             if (nsb) {
                 sc->lmc_rxq[i] = nsb;
                 nsb->dev = dev;
-                sc->lmc_rxring[i].buffer1 = virt_to_bus (nsb->tail);
+                sc->lmc_rxring[i].buffer1 = virt_to_bus(skb_tail_pointer(nsb));
             }
             sc->failed_recv_alloc = 1;
             goto skip_packet;
···
             if (nsb) {
                 sc->lmc_rxq[i] = nsb;
                 nsb->dev = dev;
-                sc->lmc_rxring[i].buffer1 = virt_to_bus (nsb->tail);
+                sc->lmc_rxring[i].buffer1 = virt_to_bus(skb_tail_pointer(nsb));
                 /* Transferred to 21140 below */
             }
             else {

drivers/net/wireless/hostap/hostap_80211_rx.c

···
 		if (frag != 0)
 			flen -= hdrlen;
 
-		if (frag_skb->tail + flen > frag_skb->end) {
+		if (skb_tail_pointer(frag_skb) + flen > frag_skb->end) {
 			printk(KERN_WARNING "%s: host decrypted and "
 			       "reassembled frame did not fit skb\n",
 			       dev->name);

drivers/s390/net/ctcmain.c

···
 			spin_unlock(&ch->collect_lock);
 			return;
 		}
-		ch->trans_skb->tail = ch->trans_skb->data = ch->trans_skb_data;
+		ch->trans_skb->data = ch->trans_skb_data;
+		skb_reset_tail_pointer(ch->trans_skb);
 		ch->trans_skb->len = 0;
 		if (ch->prof.maxmulti < (ch->collect_len + 2))
 			ch->prof.maxmulti = ch->collect_len + 2;
···
 		ctc_unpack_skb(ch, skb);
 	}
  again:
-	skb->data = skb->tail = ch->trans_skb_data;
+	skb->data = ch->trans_skb_data;
+	skb_reset_tail_pointer(skb);
 	skb->len = 0;
 	if (ctc_checkalloc_buffer(ch, 1))
 		return;
···
 		 * IDAL support in CTC is broken, so we have to
 		 * care about skb's above 2G ourselves.
 		 */
-		hi = ((unsigned long) skb->tail + LL_HEADER_LENGTH) >> 31;
+		hi = ((unsigned long)skb_tail_pointer(skb) +
+		      LL_HEADER_LENGTH) >> 31;
 		if (hi) {
 			nskb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
 			if (!nskb) {
···
 				return -EBUSY;
 			}
 
-			ch->trans_skb->tail = ch->trans_skb->data;
+			skb_reset_tail_pointer(ch->trans_skb);
 			ch->trans_skb->len = 0;
 			ch->ccw[1].count = skb->len;
 			memcpy(skb_put(ch->trans_skb, skb->len), skb->data,

drivers/s390/net/netiucv.c

···
 			       msg->length, conn->max_buffsize);
 		return;
 	}
-	conn->rx_buff->data = conn->rx_buff->tail = conn->rx_buff->head;
+	conn->rx_buff->data = conn->rx_buff->head;
+	skb_reset_tail_pointer(conn->rx_buff);
 	conn->rx_buff->len = 0;
 	rc = iucv_message_receive(conn->path, msg, 0, conn->rx_buff->data,
 				  msg->length, NULL);
···
 			}
 		}
 	}
-	conn->tx_buff->data = conn->tx_buff->tail = conn->tx_buff->head;
+	conn->tx_buff->data = conn->tx_buff->head;
+	skb_reset_tail_pointer(conn->tx_buff);
 	conn->tx_buff->len = 0;
 	spin_lock_irqsave(&conn->collect_lock, saveflags);
 	while ((skb = skb_dequeue(&conn->collect_queue))) {
···
 		 * Copy the skb to a new allocated skb in lowmem only if the
 		 * data is located above 2G in memory or tailroom is < 2.
 		 */
-		unsigned long hi =
-			((unsigned long)(skb->tail + NETIUCV_HDRLEN)) >> 31;
+		unsigned long hi = ((unsigned long)(skb_tail_pointer(skb) +
+				    NETIUCV_HDRLEN)) >> 31;
 		int copied = 0;
 		if (hi || (skb_tailroom(skb) < 2)) {
 			nskb = alloc_skb(skb->len + NETIUCV_HDRLEN +

drivers/usb/atm/usbatm.c

···
 
 	sarb = instance->cached_vcc->sarb;
 
-	if (sarb->tail + ATM_CELL_PAYLOAD > sarb->end) {
+	if (skb_tail_pointer(sarb) + ATM_CELL_PAYLOAD > sarb->end) {
 		atm_rldbg(instance, "%s: buffer overrun (sarb->len %u, vcc: 0x%p)!\n",
 				__func__, sarb->len, vcc);
 		/* discard cells already received */
 		skb_trim(sarb, 0);
-		UDSL_ASSERT(sarb->tail + ATM_CELL_PAYLOAD <= sarb->end);
+		UDSL_ASSERT(skb_tail_pointer(sarb) + ATM_CELL_PAYLOAD <= sarb->end);
 	}
 
-	memcpy(sarb->tail, source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
+	memcpy(skb_tail_pointer(sarb), source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
 	__skb_put(sarb, ATM_CELL_PAYLOAD);
 
 	if (pti & 1) {
···
 			goto out;
 		}
 
-		if (crc32_be(~0, sarb->tail - pdu_length, pdu_length) != 0xc704dd7b) {
+		if (crc32_be(~0, skb_tail_pointer(sarb) - pdu_length, pdu_length) != 0xc704dd7b) {
 			atm_rldbg(instance, "%s: packet failed crc check (vcc: 0x%p)!\n",
 				  __func__, vcc);
 			atomic_inc(&vcc->stats->rx_err);
···
 			goto out;	/* atm_charge increments rx_drop */
 		}
 
-		memcpy(skb->data, sarb->tail - pdu_length, length);
+		memcpy(skb->data, skb_tail_pointer(sarb) - pdu_length, length);
 		__skb_put(skb, length);
 
 		vdbg("%s: sending skb 0x%p, skb->len %u, skb->truesize %u",

drivers/usb/net/asix.c

···
 		if (ax_skb) {
 			ax_skb->len = size;
 			ax_skb->data = packet;
-			ax_skb->tail = packet + size;
+			skb_set_tail_pointer(ax_skb, size);
 			usbnet_skb_return(dev, ax_skb);
 		} else {
 			return 0;
···
 	    && ((headroom + tailroom) >= (4 + padlen))) {
 		if ((headroom < 4) || (tailroom < padlen)) {
 			skb->data = memmove(skb->head + 4, skb->data, skb->len);
-			skb->tail = skb->data + skb->len;
+			skb_set_tail_pointer(skb, skb->len);
 		}
 	} else {
 		struct sk_buff *skb2;
···
 
 	if ((skb->len % 512) == 0) {
 		cpu_to_le32s(&padbytes);
-		memcpy( skb->tail, &padbytes, sizeof(padbytes));
+		memcpy(skb_tail_pointer(skb), &padbytes, sizeof(padbytes));
 		skb_put(skb, sizeof(padbytes));
 	}
 	return skb;

drivers/usb/net/gl620a.c

···
 		if ((headroom < (4 + 4*1)) || (tailroom < padlen)) {
 			skb->data = memmove(skb->head + (4 + 4*1),
 					     skb->data, skb->len);
-			skb->tail = skb->data + skb->len;
+			skb_set_tail_pointer(skb, skb->len);
 		}
 	} else {
 		struct sk_buff	*skb2;

drivers/usb/net/net1080.c

···
 			skb->data = memmove(skb->head
 						+ sizeof (struct nc_header),
 					    skb->data, skb->len);
-			skb->tail = skb->data + len;
+			skb_set_tail_pointer(skb, len);
 			goto encapsulate;
 		}
 	}

drivers/usb/net/rndis_host.c

···
 		if (likely((sizeof *hdr) <= room)) {
 			skb->data = memmove(skb->head + sizeof *hdr,
 					    skb->data, len);
-			skb->tail = skb->data + len;
+			skb_set_tail_pointer(skb, len);
 			goto fill;
 		}
 	}

include/linux/netfilter/nfnetlink.h

···
 #define NFA_DATA(nfa)   ((void *)(((char *)(nfa)) + NFA_LENGTH(0)))
 #define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0))
 #define NFA_NEST(skb, type) \
-({	struct nfattr *__start = (struct nfattr *) (skb)->tail; \
+({	struct nfattr *__start = (struct nfattr *)skb_tail_pointer(skb); \
 	NFA_PUT(skb, (NFNL_NFA_NEST | type), 0, NULL); \
 	__start;  })
 #define NFA_NEST_END(skb, start) \
-({      (start)->nfa_len = ((skb)->tail - (unsigned char *) (start)); \
+({      (start)->nfa_len = skb_tail_pointer(skb) - (unsigned char *)(start); \
         (skb)->len; })
 #define NFA_NEST_CANCEL(skb, start) \
 ({      if (start) \

include/linux/netlink.h

···
 		  (cb)->nlh->nlmsg_seq, type, len, flags)
 
 #define NLMSG_END(skb, nlh) \
-({	(nlh)->nlmsg_len = (skb)->tail - (unsigned char *) (nlh); \
+({	(nlh)->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)(nlh); \
 	(skb)->len; })
 
 #define NLMSG_CANCEL(skb, nlh) \

include/linux/rtnetlink.h

···
 
 #define RTA_PUT_NOHDR(skb, attrlen, data) \
 ({	RTA_APPEND(skb, RTA_ALIGN(attrlen), data); \
-	memset(skb->tail - (RTA_ALIGN(attrlen) - attrlen), 0, \
+	memset(skb_tail_pointer(skb) - (RTA_ALIGN(attrlen) - attrlen), 0, \
 	       RTA_ALIGN(attrlen) - attrlen); })
 
 #define RTA_PUT_U8(skb, attrtype, value) \
···
 	RTA_PUT(skb, attrtype, 0, NULL);
 
 #define RTA_NEST(skb, type) \
-({	struct rtattr *__start = (struct rtattr *) (skb)->tail; \
+({	struct rtattr *__start = (struct rtattr *)skb_tail_pointer(skb); \
 	RTA_PUT(skb, type, 0, NULL); \
 	__start;  })
 
 #define RTA_NEST_END(skb, start) \
-({	(start)->rta_len = ((skb)->tail - (unsigned char *) (start)); \
+({	(start)->rta_len = skb_tail_pointer(skb) - (unsigned char *)(start); \
 	(skb)->len; })
 
 #define RTA_NEST_CANCEL(skb, start) \

include/linux/skbuff.h

···
 	int			iif;
 	/* 4 byte hole on 64 bit*/
 
-	sk_buff_data_t		transport_header;
-	sk_buff_data_t		network_header;
-	sk_buff_data_t		mac_header;
 	struct  dst_entry	*dst;
 	struct	sec_path	*sp;
 
···
 
 	__u32			mark;
 
+	sk_buff_data_t		transport_header;
+	sk_buff_data_t		network_header;
+	sk_buff_data_t		mac_header;
 	/* These elements must be at the end, see alloc_skb() for details.  */
-	unsigned int		truesize;
-	atomic_t		users;
+	sk_buff_data_t		tail;
 	unsigned char		*head,
 				*data,
-				*tail,
 				*end;
+	unsigned int		truesize;
+	atomic_t		users;
 };
 
 #ifdef __KERNEL__
···
 #define SKB_FRAG_ASSERT(skb) 	BUG_ON(skb_shinfo(skb)->frag_list)
 #define SKB_LINEAR_ASSERT(skb)  BUG_ON(skb_is_nonlinear(skb))
 
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
+{
+	return skb->head + skb->tail;
+}
+
+static inline void skb_reset_tail_pointer(struct sk_buff *skb)
+{
+	skb->tail = skb->data - skb->head;
+}
+
+static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
+{
+	skb_reset_tail_pointer(skb);
+	skb->tail += offset;
+}
+#else /* NET_SKBUFF_DATA_USES_OFFSET */
+static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
+{
+	return skb->tail;
+}
+
+static inline void skb_reset_tail_pointer(struct sk_buff *skb)
+{
+	skb->tail = skb->data;
+}
+
+static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
+{
+	skb->tail = skb->data + offset;
+}
+#endif /* NET_SKBUFF_DATA_USES_OFFSET */
+
 /*
  *	Add data to an sk_buff
  */
 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
 {
-	unsigned char *tmp = skb->tail;
+	unsigned char *tmp = skb_tail_pointer(skb);
 	SKB_LINEAR_ASSERT(skb);
 	skb->tail += len;
 	skb->len  += len;
···
  */
 static inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
 {
-	unsigned char *tmp = skb->tail;
+	unsigned char *tmp = skb_tail_pointer(skb);
 	SKB_LINEAR_ASSERT(skb);
 	skb->tail += len;
 	skb->len  += len;
-	if (unlikely(skb->tail>skb->end))
+	if (unlikely(skb_tail_pointer(skb) > skb->end))
 		skb_over_panic(skb, len, current_text_addr());
 	return tmp;
 }
···
  */
 static inline int skb_tailroom(const struct sk_buff *skb)
 {
-	return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
+	return skb_is_nonlinear(skb) ? 0 : skb->end - skb_tail_pointer(skb);
 }
 
 /**
···
 		WARN_ON(1);
 		return;
 	}
-	skb->len  = len;
-	skb->tail = skb->data + len;
+	skb->len = len;
+	skb_set_tail_pointer(skb, len);
 }
 
 /**

include/net/inet_ecn.h

···
 {
 	switch (skb->protocol) {
 	case __constant_htons(ETH_P_IP):
-		if (skb_network_header(skb) + sizeof(struct iphdr) <=
-		    skb->tail)
+		if (skb->network_header + sizeof(struct iphdr) <= skb->tail)
 			return IP_ECN_set_ce(ip_hdr(skb));
 		break;
 
 	case __constant_htons(ETH_P_IPV6):
-		if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
-		    skb->tail)
+		if (skb->network_header + sizeof(struct ipv6hdr) <= skb->tail)
 			return IP6_ECN_set_ce(ipv6_hdr(skb));
 		break;
 	}

include/net/netlink.h

···
  */
 static inline int nlmsg_end(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
-	nlh->nlmsg_len = skb->tail - (unsigned char *) nlh;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
 
 	return skb->len;
 }
···
  */
 static inline void *nlmsg_get_pos(struct sk_buff *skb)
 {
-	return skb->tail;
+	return skb_tail_pointer(skb);
 }
 
 /**
···
  */
 static inline struct nlattr *nla_nest_start(struct sk_buff *skb, int attrtype)
 {
-	struct nlattr *start = (struct nlattr *) skb->tail;
+	struct nlattr *start = (struct nlattr *)skb_tail_pointer(skb);
 
 	if (nla_put(skb, attrtype, 0, NULL) < 0)
 		return NULL;
···
  */
 static inline int nla_nest_end(struct sk_buff *skb, struct nlattr *start)
 {
-	start->nla_len = skb->tail - (unsigned char *) start;
+	start->nla_len = skb_tail_pointer(skb) - (unsigned char *)start;
 	return skb->len;
 }
 

include/net/pkt_cls.h

···
 static inline int tcf_valid_offset(const struct sk_buff *skb,
 				   const unsigned char *ptr, const int len)
 {
-	return unlikely((ptr + len) < skb->tail && ptr > skb->head);
+	return unlikely((ptr + len) < skb_tail_pointer(skb) && ptr > skb->head);
 }
 
 #ifdef CONFIG_NET_CLS_IND

kernel/audit.c

···
 			goto out;
 	}
 	va_copy(args2, args);
-	len = vsnprintf(skb->tail, avail, fmt, args);
+	len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
 	if (len >= avail) {
 		/* The printk buffer is 1024 bytes long, so if we get
 		 * here and AUDIT_BUFSIZ is at least 1024, then we can
···
 			max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
 		if (!avail)
 			goto out;
-		len = vsnprintf(skb->tail, avail, fmt, args2);
+		len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
 	}
 	if (len > 0)
 		skb_put(skb, len);
···
 			return;
 	}
 
-	ptr = skb->tail;
+	ptr = skb_tail_pointer(skb);
 	for (i=0; i<len; i++) {
 		*ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
 		*ptr++ = hex[buf[i] & 0x0F];	  /* Lower nibble */
···
 		if (!avail)
 			return;
 	}
-	ptr = skb->tail;
+	ptr = skb_tail_pointer(skb);
 	*ptr++ = '"';
 	memcpy(ptr, string, slen);
 	ptr += slen;

net/atm/lec.c

···
 	}
 
 	DPRINTK("skbuff head:%lx data:%lx tail:%lx end:%lx\n",
-		(long)skb->head, (long)skb->data, (long)skb->tail,
+		(long)skb->head, (long)skb->data, (long)skb_tail_pointer(skb),
 		(long)skb->end);
 #if defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
 	if (memcmp(skb->data, bridge_ula_lec, sizeof(bridge_ula_lec)) == 0)

net/bluetooth/rfcomm/core.c

···
 
 	/* Trim FCS */
 	skb->len--; skb->tail--;
-	fcs = *(u8 *) skb->tail;
+	fcs = *(u8 *)skb_tail_pointer(skb);
 
 	if (__check_fcs(skb->data, type, fcs)) {
 		BT_ERR("bad checksum in packet");

net/core/dev.c

···
 			skb_reset_mac_header(skb2);
 
 			if (skb_network_header(skb2) < skb2->data ||
-			    skb_network_header(skb2) > skb2->tail) {
+			    skb2->network_header > skb2->tail) {
 				if (net_ratelimit())
 					printk(KERN_CRIT "protocol %04x is "
 					       "buggy, dev %s\n",
···
 	BUG_ON(offset > (int)skb->len);
 	csum = skb_checksum(skb, offset, skb->len-offset, 0);
 
-	offset = skb->tail - skb_transport_header(skb);
+	offset = skb->tail - skb->transport_header;
 	BUG_ON(offset <= 0);
 	BUG_ON(skb->csum_offset + 2 > offset);
 

net/core/filter.c

···
 	else if (k >= SKF_LL_OFF)
 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
 
-	if (ptr >= skb->head && ptr < skb->tail)
+	if (ptr >= skb->head && ptr < skb_tail_pointer(skb))
 		return ptr;
 	return NULL;
 }

net/core/gen_stats.c

···
 	spin_lock_bh(lock);
 	d->lock = lock;
 	if (type)
-		d->tail = (struct rtattr *) skb->tail;
+		d->tail = (struct rtattr *)skb_tail_pointer(skb);
 	d->skb = skb;
 	d->compat_tc_stats = tc_stats_type;
 	d->compat_xstats = xstats_type;
···
 gnet_stats_finish_copy(struct gnet_dump *d)
 {
 	if (d->tail)
-		d->tail->rta_len = d->skb->tail - (u8 *) d->tail;
+		d->tail->rta_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 
 	if (d->compat_tc_stats)
 		if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,

net/core/pktgen.c

···
 		*vlan_encapsulated_proto = htons(ETH_P_IP);
 	}
 
-	skb_set_network_header(skb, skb->tail - skb->data);
+	skb->network_header = skb->tail;
 	skb->transport_header = skb->network_header + sizeof(struct iphdr);
 	skb_put(skb, sizeof(struct iphdr) + sizeof(struct udphdr));
 
···
 		*vlan_encapsulated_proto = htons(ETH_P_IPV6);
 	}
 
-	skb_set_network_header(skb, skb->tail - skb->data);
+	skb->network_header = skb->tail;
 	skb->transport_header = skb->network_header + sizeof(struct ipv6hdr);
 	skb_put(skb, sizeof(struct ipv6hdr) + sizeof(struct udphdr));
 

net/core/skbuff.c

···
 void skb_over_panic(struct sk_buff *skb, int sz, void *here)
 {
 	printk(KERN_EMERG "skb_over_panic: text:%p len:%d put:%d head:%p "
-			  "data:%p tail:%p end:%p dev:%s\n",
-	       here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end,
+			  "data:%p tail:%#lx end:%p dev:%s\n",
+	       here, skb->len, sz, skb->head, skb->data,
+	       (unsigned long)skb->tail, skb->end,
 	       skb->dev ? skb->dev->name : "<NULL>");
 	BUG();
 }
···
 void skb_under_panic(struct sk_buff *skb, int sz, void *here)
 {
 	printk(KERN_EMERG "skb_under_panic: text:%p len:%d put:%d head:%p "
-			  "data:%p tail:%p end:%p dev:%s\n",
-	       here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end,
+			  "data:%p tail:%#lx end:%p dev:%s\n",
+	       here, skb->len, sz, skb->head, skb->data,
+	       (unsigned long)skb->tail, skb->end,
 	       skb->dev ? skb->dev->name : "<NULL>");
 	BUG();
 }
···
 	atomic_set(&skb->users, 1);
 	skb->head = data;
 	skb->data = data;
-	skb->tail = data;
+	skb_reset_tail_pointer(skb);
 	skb->end  = data + size;
 	/* make sure we initialize shinfo sequentially */
 	shinfo = skb_shinfo(skb);
···
 
 	/* Copy only real data... and, alas, header. This should be
 	 * optimized for the cases when header is void. */
-	memcpy(data + nhead, skb->head, skb->tail - skb->head);
+	memcpy(data + nhead, skb->head,
+		skb->tail
+#ifndef NET_SKBUFF_DATA_USES_OFFSET
+		- skb->head
+#endif
+		);
 	memcpy(data + size, skb->end, sizeof(struct skb_shared_info));
 
 	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
···
 	skb->head     = data;
 	skb->end      = data + size;
 	skb->data    += off;
-	skb->tail    += off;
 #ifndef NET_SKBUFF_DATA_USES_OFFSET
-	/* {transport,network,mac}_header are relative to skb->head */
+	/* {transport,network,mac}_header and tail are relative to skb->head */
+	skb->tail	      += off;
 	skb->transport_header += off;
 	skb->network_header   += off;
 	skb->mac_header	      += off;
···
 		return 0;
 	}
 
-	ntail = skb->data_len + pad - (skb->end - skb->tail);
+	ntail = skb->data_len + pad - (skb->end - skb_tail_pointer(skb));
 	if (likely(skb_cloned(skb) || ntail > 0)) {
 		err = pskb_expand_head(skb, 0, ntail, GFP_ATOMIC);
 		if (unlikely(err))
···
 	} else {
 		skb->len       = len;
 		skb->data_len  = 0;
-		skb->tail      = skb->data + len;
+		skb_set_tail_pointer(skb, len);
 	}
 
 	return 0;
···
 	 * plus 128 bytes for future expansions. If we have enough
 	 * room at tail, reallocate without expansion only if skb is cloned.
 	 */
-	int i, k, eat = (skb->tail + delta) - skb->end;
+	int i, k, eat = (skb_tail_pointer(skb) + delta) - skb->end;
 
 	if (eat > 0 || skb_cloned(skb)) {
 		if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0,
···
 			return NULL;
 	}
 
-	if (skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta))
+	if (skb_copy_bits(skb, skb_headlen(skb), skb_tail_pointer(skb), delta))
 		BUG();
 
 	/* Optimization: no fragments, no reasons to preestimate
···
 	skb->tail     += delta;
 	skb->data_len -= delta;
 
-	return skb->tail;
+	return skb_tail_pointer(skb);
 }
 
 /* Copy some data bits from skb to kernel buffer. */
···
 	skb1->len		   += skb1->data_len;
 	skb->data_len		   = 0;
 	skb->len		   = len;
-	skb->tail		   = skb->data + len;
+	skb_set_tail_pointer(skb, len);
 }
 
 static inline void skb_split_no_header(struct sk_buff *skb,

net/core/wireless.c

···
 {
 	struct ifinfomsg *r;
 	struct nlmsghdr  *nlh;
-	unsigned char	 *b = skb->tail;
+	unsigned char	 *b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_PUT(skb, 0, 0, type, sizeof(*r));
 	r = NLMSG_DATA(nlh);
···
 	/* Add the wireless events in the netlink packet */
 	RTA_PUT(skb, IFLA_WIRELESS, event_len, event);
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:

net/decnet/dn_nsp_out.c

···
 	if (scp->peer.sdn_objnum)
 		type = 0;
 
-	skb_put(skb, dn_sockaddr2username(&scp->peer, skb->tail, type));
-	skb_put(skb, dn_sockaddr2username(&scp->addr, skb->tail, 2));
+	skb_put(skb, dn_sockaddr2username(&scp->peer,
+					  skb_tail_pointer(skb), type));
+	skb_put(skb, dn_sockaddr2username(&scp->addr,
+					  skb_tail_pointer(skb), 2));
 
 	menuver = DN_MENUVER_ACC | DN_MENUVER_USR;
 	if (scp->peer.sdn_flags & SDF_PROXY)

net/decnet/dn_route.c

···
 	struct dn_route *rt = (struct dn_route *)skb->dst;
 	struct rtmsg *r;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	long expires;
 
 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags);
···
 	if (rt->fl.iif)
 		RTA_PUT(skb, RTA_IIF, sizeof(int), &rt->fl.iif);
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:

net/decnet/dn_table.c

···
 {
 	struct rtmsg *rtm;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*rtm), flags);
 	rtm = NLMSG_DATA(nlh);
···
 			nhp->rtnh_ifindex = nh->nh_oif;
 			if (nh->nh_gw)
 				RTA_PUT(skb, RTA_GATEWAY, 2, &nh->nh_gw);
-			nhp->rtnh_len = skb->tail - (unsigned char *)nhp;
+			nhp->rtnh_len = skb_tail_pointer(skb) - (unsigned char *)nhp;
 		} endfor_nexthops(fi);
 		mp_head->rta_type = RTA_MULTIPATH;
-		mp_head->rta_len = skb->tail - (u8*)mp_head;
+		mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
 	}
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 

net/decnet/netfilter/dn_rtmsg.c

···
 {
 	struct sk_buff *skb = NULL;
 	size_t size;
-	unsigned char *old_tail;
+	sk_buff_data_t old_tail;
 	struct nlmsghdr *nlh;
 	unsigned char *ptr;
 	struct nf_dn_rtmsg *rtm;

net/econet/af_econet.c

···
 			fh->cb = cb;
 			fh->port = port;
 			if (sock->type != SOCK_DGRAM) {
-				skb->tail = skb->data;
+				skb_reset_tail_pointer(skb);
 				skb->len = 0;
 			} else if (res < 0)
 				goto out_free;

net/ieee80211/ieee80211_rx.c

···
 		if (frag != 0)
 			flen -= hdrlen;
 
-		if (frag_skb->tail + flen > frag_skb->end) {
+		if (skb_tail_pointer(frag_skb) + flen > frag_skb->end) {
 			printk(KERN_WARNING "%s: host decrypted and "
 			       "reassembled frame did not fit skb\n",
 			       dev->name);

net/ipv4/esp4.c

···
 	struct blkcipher_desc desc;
 	struct esp_data *esp;
 	struct sk_buff *trailer;
+	u8 *tail;
 	int blksize;
 	int clen;
 	int alen;
···
 		goto error;
 
 	/* Fill padding... */
+	tail = skb_tail_pointer(trailer);
 	do {
 		int i;
 		for (i=0; i<clen-skb->len - 2; i++)
-			*(u8*)(trailer->tail + i) = i+1;
+			tail[i] = i + 1;
 	} while (0);
-	*(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
+	tail[clen - skb->len - 2] = (clen - skb->len) - 2;
 	pskb_put(skb, trailer, clen - skb->len);
 
 	__skb_push(skb, skb->data - skb_network_header(skb));
···
 	esph = (struct ip_esp_hdr *)(skb_network_header(skb) +
 				     top_iph->ihl * 4);
 	top_iph->tot_len = htons(skb->len + alen);
-	*(u8*)(trailer->tail - 1) = top_iph->protocol;
+	*(skb_tail_pointer(skb) - 1) = top_iph->protocol;
 
 	/* this is non-NULL only with UDP Encapsulation */
 	if (x->encap) {

net/ipv4/icmp.c

···
 	 */
 	iph = ip_hdr(skb_in);
 
-	if ((u8 *)iph < skb_in->head || (u8 *)(iph + 1) > skb_in->tail)
+	if ((u8 *)iph < skb_in->head ||
+	    (skb_in->network_header + sizeof(*iph)) > skb_in->tail)
 		goto out;
 
 	/*

net/ipv4/igmp.c

···
 {
 	struct iphdr *pip = ip_hdr(skb);
 	struct igmphdr *pig = igmp_hdr(skb);
-	const int iplen = skb->tail - skb_network_header(skb);
-	const int igmplen = skb->tail - skb_transport_header(skb);
+	const int iplen = skb->tail - skb->network_header;
+	const int igmplen = skb->tail - skb->transport_header;
 
 	pip->tot_len = htons(iplen);
 	ip_send_check(pip);

net/ipv4/inet_diag.c

···
 	struct nlmsghdr  *nlh;
 	void *info = NULL;
 	struct inet_diag_meminfo  *minfo = NULL;
-	unsigned char	 *b = skb->tail;
+	unsigned char	 *b = skb_tail_pointer(skb);
 	const struct inet_diag_handler *handler;
 
 	handler = inet_diag_table[unlh->nlmsg_type];
···
 	    icsk->icsk_ca_ops && icsk->icsk_ca_ops->get_info)
 		icsk->icsk_ca_ops->get_info(sk, ext, skb);
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:
···
 {
 	long tmo;
 	struct inet_diag_msg *r;
-	const unsigned char *previous_tail = skb->tail;
+	const unsigned char *previous_tail = skb_tail_pointer(skb);
 	struct nlmsghdr *nlh = NLMSG_PUT(skb, pid, seq,
 					 unlh->nlmsg_type, sizeof(*r));
 
···
 			       &tw6->tw_v6_daddr);
 	}
 #endif
-	nlh->nlmsg_len = skb->tail - previous_tail;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - previous_tail;
 	return skb->len;
 nlmsg_failure:
 	skb_trim(skb, previous_tail - skb->data);
···
 {
 	const struct inet_request_sock *ireq = inet_rsk(req);
 	struct inet_sock *inet = inet_sk(sk);
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct inet_diag_msg *r;
 	struct nlmsghdr *nlh;
 	long tmo;
···
 			       &inet6_rsk(req)->rmt_addr);
 	}
 #endif
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 
 	return skb->len;
 

net/ipv4/ip_sockglue.c

···
 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 	serr->port = port;
 
-	__skb_pull(skb, skb->tail - skb->data);
+	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 	skb_reset_transport_header(skb);
 
 	if (sock_queue_err_skb(sk, skb))

net/ipv4/ipmr.c

···
 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 
 			if (ipmr_fill_mroute(skb, c, NLMSG_DATA(nlh)) > 0) {
-				nlh->nlmsg_len = skb->tail - (u8*)nlh;
+				nlh->nlmsg_len = (skb_tail_pointer(skb) -
+						  (u8 *)nlh);
 			} else {
 				nlh->nlmsg_type = NLMSG_ERROR;
 				nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
···
 	 *	Copy the IP header
 	 */
 
-	skb_set_network_header(skb, skb->tail - skb->data);
+	skb->network_header = skb->tail;
 	skb_put(skb, ihl);
 	memcpy(skb->data,pkt->data,ihl);
 	ip_hdr(skb)->protocol = 0;			/* Flag to the kernel this is a route add */
···
 	int ct;
 	struct rtnexthop *nhp;
 	struct net_device *dev = vif_table[c->mfc_parent].dev;
-	u8 *b = skb->tail;
+	u8 *b = skb_tail_pointer(skb);
 	struct rtattr *mp_head;
 
 	if (dev)
···
 		}
 	}
 	mp_head->rta_type = RTA_MULTIPATH;
-	mp_head->rta_len = skb->tail - (u8*)mp_head;
+	mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
 	rtm->rtm_type = RTN_MULTICAST;
 	return 1;
 

net/ipv4/ipvs/ip_vs_ftp.c

···
 		iph = ip_hdr(*pskb);
 		th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
 		data = (char *)th + (th->doff << 2);
-		data_limit = (*pskb)->tail;
+		data_limit = skb_tail_pointer(*pskb);
 
 		if (ip_vs_ftp_get_addrport(data, data_limit,
 					   SERVER_STRING,
···
 	   the length of the header in 32-bit multiples, it is accurate
 	   to calculate data address by th+HLEN*4 */
 	data = data_start = (char *)th + (th->doff << 2);
-	data_limit = (*pskb)->tail;
+	data_limit = skb_tail_pointer(*pskb);
 
 	while (data <= data_limit - 6) {
 		if (strnicmp(data, "PASV\r\n", 6) == 0) {

net/ipv4/netfilter/arpt_mangle.c

···
 	/* We assume that pln and hln were checked in the match */
 	if (mangle->flags & ARPT_MANGLE_SDEV) {
 		if (ARPT_DEV_ADDR_LEN_MAX < hln ||
-		   (arpptr + hln > (**pskb).tail))
+		   (arpptr + hln > skb_tail_pointer(*pskb)))
 			return NF_DROP;
 		memcpy(arpptr, mangle->src_devaddr, hln);
 	}
 	arpptr += hln;
 	if (mangle->flags & ARPT_MANGLE_SIP) {
 		if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
-		   (arpptr + pln > (**pskb).tail))
+		   (arpptr + pln > skb_tail_pointer(*pskb)))
 			return NF_DROP;
 		memcpy(arpptr, &mangle->u_s.src_ip, pln);
 	}
 	arpptr += pln;
 	if (mangle->flags & ARPT_MANGLE_TDEV) {
 		if (ARPT_DEV_ADDR_LEN_MAX < hln ||
-		   (arpptr + hln > (**pskb).tail))
+		   (arpptr + hln > skb_tail_pointer(*pskb)))
 			return NF_DROP;
 		memcpy(arpptr, mangle->tgt_devaddr, hln);
 	}
 	arpptr += hln;
 	if (mangle->flags & ARPT_MANGLE_TIP) {
 		if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
-		   (arpptr + pln > (**pskb).tail))
+		   (arpptr + pln > skb_tail_pointer(*pskb)))
 			return NF_DROP;
 		memcpy(arpptr, &mangle->u_t.tgt_ip, pln);
 	}

net/ipv4/netfilter/ip_queue.c

···
 static struct sk_buff *
 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 {
-	unsigned char *old_tail;
+	sk_buff_data_t old_tail;
 	size_t size = 0;
 	size_t data_len = 0;
 	struct sk_buff *skb;
···
 	if (!skb)
 		goto nlmsg_failure;
 
-	old_tail= skb->tail;
+	old_tail = skb->tail;
 	nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 	pmsg = NLMSG_DATA(nlh);
 	memset(pmsg, 0, sizeof(*pmsg));

net/ipv4/netfilter/nf_nat_helper.c

···
 	/* move post-replacement */
 	memmove(data + match_offset + rep_len,
 		data + match_offset + match_len,
-		skb->tail - (data + match_offset + match_len));
+		skb->tail - (skb->network_header + dataoff +
+			     match_offset + match_len));
 
 	/* insert data from buffer */
 	memcpy(data + match_offset, rep_buffer, rep_len);

net/ipv4/tcp.c

···
 		th->cwr = 0;
 	} while (skb->next);
 
-	delta = htonl(oldlen + (skb->tail - skb_transport_header(skb)) +
+	delta = htonl(oldlen + (skb->tail - skb->transport_header) +
 		      skb->data_len);
 	th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
 				(__force u32)delta));

net/ipv4/tcp_output.c

···
 	}
 	skb_shinfo(skb)->nr_frags = k;
 
-	skb->tail = skb->data;
+	skb_reset_tail_pointer(skb);
 	skb->data_len -= len;
 	skb->len = skb->data_len;
 }

net/ipv6/datagram.c

···
 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 	serr->port = fl->fl_ip_dport;
 
-	__skb_pull(skb, skb->tail - skb->data);
+	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 	skb_reset_transport_header(skb);
 
 	if (sock_queue_err_skb(sk, skb))

net/ipv6/esp6.c

···
 	int clen;
 	int alen;
 	int nfrags;
+	u8 *tail;
 	struct esp_data *esp = x->data;
 	int hdr_len = (skb_transport_offset(skb) +
 		       sizeof(*esph) + esp->conf.ivlen);
···
 	}
 
 	/* Fill padding... */
+	tail = skb_tail_pointer(trailer);
 	do {
 		int i;
 		for (i=0; i<clen-skb->len - 2; i++)
-			*(u8*)(trailer->tail + i) = i+1;
+			tail[i] = i + 1;
 	} while (0);
-	*(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
+	tail[clen-skb->len - 2] = (clen - skb->len) - 2;
 	pskb_put(skb, trailer, clen - skb->len);
 
 	top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
 	esph = (struct ipv6_esp_hdr *)skb_transport_header(skb);
 	top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
-	*(u8 *)(trailer->tail - 1) = *skb_network_header(skb);
+	*(skb_tail_pointer(skb) - 1) = *skb_network_header(skb);
 	*skb_network_header(skb) = IPPROTO_ESP;
 
 	esph->spi = x->id.spi;

net/ipv6/exthdrs.c

···
 int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
 {
 	const unsigned char *nh = skb_network_header(skb);
-	int packet_len = skb->tail - nh;
+	int packet_len = skb->tail - skb->network_header;
 	struct ipv6_opt_hdr *hdr;
 	int len;
 

net/ipv6/icmp.c

···
 	int hlimit, tclass;
 	int err = 0;
 
-	if ((u8*)hdr < skb->head || (u8*)(hdr+1) > skb->tail)
+	if ((u8 *)hdr < skb->head ||
+	    (skb->network_header + sizeof(*hdr)) > skb->tail)
 		return;
 
 	/*

net/ipv6/ip6_output.c

···
 	u16 offset = sizeof(struct ipv6hdr);
 	struct ipv6_opt_hdr *exthdr =
 				(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
-	unsigned int packet_len = skb->tail - skb_network_header(skb);
+	unsigned int packet_len = skb->tail - skb->network_header;
 	int found_rhdr = 0;
 	*nexthdr = &ipv6_hdr(skb)->nexthdr;
 

net/ipv6/mcast.c

···
 
 	memcpy(skb_put(skb, sizeof(ra)), ra, sizeof(ra));
 
-	skb_set_transport_header(skb, skb->tail - skb->data);
+	skb_set_transport_header(skb, skb_tail_pointer(skb) - skb->data);
 	skb_put(skb, sizeof(*pmr));
 	pmr = (struct mld2_report *)skb_transport_header(skb);
 	pmr->type = ICMPV6_MLD2_REPORT;
···
 	int err;
 
 	IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
-	payload_len = skb->tail - skb_network_header(skb) - sizeof(*pip6);
-	mldlen = skb->tail - skb_transport_header(skb);
+	payload_len = (skb->tail - skb->network_header) - sizeof(*pip6);
+	mldlen = skb->tail - skb->transport_header;
 	pip6->payload_len = htons(payload_len);
 
 	pmr->csum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,

net/ipv6/mip6.c

···
 	struct ipv6_opt_hdr *exthdr =
 				   (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
 	const unsigned char *nh = skb_network_header(skb);
-	unsigned int packet_len = skb->tail - nh;
+	unsigned int packet_len = skb->tail - skb->network_header;
 	int found_rhdr = 0;
 
 	*nexthdr = &ipv6_hdr(skb)->nexthdr;
···
 	struct ipv6_opt_hdr *exthdr =
 				   (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
 	const unsigned char *nh = skb_network_header(skb);
-	unsigned int packet_len = skb->tail - nh;
+	unsigned int packet_len = skb->tail - skb->network_header;
 	int found_rhdr = 0;
 
 	*nexthdr = &ipv6_hdr(skb)->nexthdr;

net/ipv6/ndisc.c

···
 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
 	ip6_nd_hdr(sk, skb, dev, src_addr, daddr, IPPROTO_ICMPV6, len);
 
-	skb_set_transport_header(skb, skb->tail - skb->data);
+	skb->transport_header = skb->tail;
 	skb_put(skb, len);
 	msg = (struct nd_msg *)skb_transport_header(skb);
 
···
 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
 	ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 
-	skb_set_transport_header(skb, skb->tail - skb->data);
+	skb->transport_header = skb->tail;
 	skb_put(skb, len);
 	msg = (struct nd_msg *)skb_transport_header(skb);
 	msg->icmph.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION;
···
 	skb_reserve(skb, LL_RESERVED_SPACE(dev));
 	ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 
-	skb_set_transport_header(skb, skb->tail - skb->data);
+	skb->transport_header = skb->tail;
 	skb_put(skb, len);
 	hdr = icmp6_hdr(skb);
 	hdr->icmp6_type = NDISC_ROUTER_SOLICITATION;
···
 	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 	struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 	u8 *lladdr = NULL;
-	u32 ndoptlen = skb->tail - msg->opt;
+	u32 ndoptlen = skb->tail - (skb->transport_header +
+				    offsetof(struct nd_msg, opt));
 	struct ndisc_options ndopts;
 	struct net_device *dev = skb->dev;
 	struct inet6_ifaddr *ifp;
···
 	struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
 	struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
 	u8 *lladdr = NULL;
-	u32 ndoptlen = skb->tail - msg->opt;
+	u32 ndoptlen = skb->tail - (skb->transport_header +
+				    offsetof(struct nd_msg, opt));
 	struct ndisc_options ndopts;
 	struct net_device *dev = skb->dev;
 	struct inet6_ifaddr *ifp;
···
 
 	__u8 * opt = (__u8 *)(ra_msg + 1);
 
-	optlen = (skb->tail - skb_transport_header(skb)) -
-		  sizeof(struct ra_msg);
+	optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg);
 
 	if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) {
 		ND_PRINTK2(KERN_WARNING
···
 		return;
 	}
 
-	optlen = skb->tail - skb_transport_header(skb);
+	optlen = skb->tail - skb->transport_header;
 	optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr);
 
 	if (optlen < 0) {
···
 	ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr,
 		   IPPROTO_ICMPV6, len);
 
-	skb_set_transport_header(buff, buff->tail - buff->data);
+	skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data);
 	skb_put(buff, len);
 	icmph = icmp6_hdr(buff);
 

net/ipv6/netfilter/ip6_queue.c

···
 static struct sk_buff *
 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 {
-	unsigned char *old_tail;
+	sk_buff_data_t old_tail;
 	size_t size = 0;
 	size_t data_len = 0;
 	struct sk_buff *skb;
···
 	if (!skb)
 		goto nlmsg_failure;
 
-	old_tail= skb->tail;
+	old_tail = skb->tail;
 	nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 	pmsg = NLMSG_DATA(nlh);
 	memset(pmsg, 0, sizeof(*pmsg));

net/ipv6/raw.c

···
 			spin_lock_bh(&sk->sk_receive_queue.lock);
 			skb = skb_peek(&sk->sk_receive_queue);
 			if (skb != NULL)
-				amount = skb->tail - skb_transport_header(skb);
+				amount = skb->tail - skb->transport_header;
 			spin_unlock_bh(&sk->sk_receive_queue.lock);
 			return put_user(amount, (int __user *)arg);
 		}

net/irda/ircomm/ircomm_param.c

···
 	 * Inserting is a little bit tricky since we don't know how much
 	 * room we will need. But this should hopefully work OK
 	 */
-	count = irda_param_insert(self, pi, skb->tail, skb_tailroom(skb),
-				  &ircomm_param_info);
+	count = irda_param_insert(self, pi, skb_tail_pointer(skb),
+				  skb_tailroom(skb), &ircomm_param_info);
 	if (count < 0) {
 		IRDA_WARNING("%s(), no room for parameter!\n", __FUNCTION__);
 		spin_unlock_irqrestore(&self->spinlock, flags);

net/irda/irlan/irlan_common.c

···
 	}
 
 	/* Insert at end of sk-buffer */
-	frame = skb->tail;
+	frame = skb_tail_pointer(skb);
 
 	/* Make space for data */
 	if (skb_tailroom(skb) < (param_len+value_len+3)) {

net/irda/qos.c

···
 	int ret;
 
 	/* Insert data rate */
-	ret = irda_param_insert(self, PI_BAUD_RATE, skb->tail,
+	ret = irda_param_insert(self, PI_BAUD_RATE, skb_tail_pointer(skb),
 				skb_tailroom(skb), &irlap_param_info);
 	if (ret < 0)
 		return ret;
 	skb_put(skb, ret);
 
 	/* Insert max turnaround time */
-	ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb->tail,
+	ret = irda_param_insert(self, PI_MAX_TURN_TIME, skb_tail_pointer(skb),
 				skb_tailroom(skb), &irlap_param_info);
 	if (ret < 0)
 		return ret;
 	skb_put(skb, ret);
 
 	/* Insert data size */
-	ret = irda_param_insert(self, PI_DATA_SIZE, skb->tail,
+	ret = irda_param_insert(self, PI_DATA_SIZE, skb_tail_pointer(skb),
 				skb_tailroom(skb), &irlap_param_info);
 	if (ret < 0)
 		return ret;
 	skb_put(skb, ret);
 
 	/* Insert window size */
-	ret = irda_param_insert(self, PI_WINDOW_SIZE, skb->tail,
+	ret = irda_param_insert(self, PI_WINDOW_SIZE, skb_tail_pointer(skb),
 				skb_tailroom(skb), &irlap_param_info);
 	if (ret < 0)
 		return ret;
 	skb_put(skb, ret);
 
 	/* Insert additional BOFs */
-	ret = irda_param_insert(self, PI_ADD_BOFS, skb->tail,
+	ret = irda_param_insert(self, PI_ADD_BOFS, skb_tail_pointer(skb),
 				skb_tailroom(skb), &irlap_param_info);
 	if (ret < 0)
 		return ret;
 	skb_put(skb, ret);
 
 	/* Insert minimum turnaround time */
-	ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb->tail,
+	ret = irda_param_insert(self, PI_MIN_TURN_TIME, skb_tail_pointer(skb),
 				skb_tailroom(skb), &irlap_param_info);
 	if (ret < 0)
 		return ret;
 	skb_put(skb, ret);
 
 	/* Insert link disconnect/threshold time */
-	ret = irda_param_insert(self, PI_LINK_DISC, skb->tail,
+	ret = irda_param_insert(self, PI_LINK_DISC, skb_tail_pointer(skb),
 				skb_tailroom(skb), &irlap_param_info);
 	if (ret < 0)
 		return ret;

net/netfilter/nf_conntrack_netlink.c

···
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfmsg;
 	struct nfattr *nest_parms;
-	unsigned char *b;
-
-	b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	event |= NFNL_SUBSYS_CTNETLINK << 8;
 	nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
···
 	    ctnetlink_dump_use(skb, ct) < 0)
 		goto nfattr_failure;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:
···
 	struct nf_conn *ct = (struct nf_conn *)ptr;
 	struct sk_buff *skb;
 	unsigned int type;
-	unsigned char *b;
+	sk_buff_data_t b;
 	unsigned int flags = 0, group;
 
 	/* ignore our fake conntrack entry */
···
 {
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfmsg;
-	unsigned char *b;
-
-	b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	event |= NFNL_SUBSYS_CTNETLINK_EXP << 8;
 	nlh    = NLMSG_PUT(skb, pid, seq, event, sizeof(struct nfgenmsg));
···
 	if (ctnetlink_exp_dump_expect(skb, exp) < 0)
 		goto nfattr_failure;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:
···
 	struct nf_conntrack_expect *exp = (struct nf_conntrack_expect *)ptr;
 	struct sk_buff *skb;
 	unsigned int type;
-	unsigned char *b;
+	sk_buff_data_t b;
 	int flags = 0;
 
 	if (events & IPEXP_NEW) {

net/netfilter/nfnetlink_log.c

···
 			const struct nf_loginfo *li,
 			const char *prefix, unsigned int plen)
 {
-	unsigned char *old_tail;
 	struct nfulnl_msg_packet_hdr pmsg;
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfmsg;
 	__be32 tmp_uint;
+	sk_buff_data_t old_tail = inst->skb->tail;
 
 	UDEBUG("entered\n");
 
-	old_tail = inst->skb->tail;
 	nlh = NLMSG_PUT(inst->skb, 0, 0,
 			NFNL_SUBSYS_ULOG << 8 | NFULNL_MSG_PACKET,
 			sizeof(struct nfgenmsg));

net/netfilter/nfnetlink_queue.c

···
 nfqnl_build_packet_message(struct nfqnl_instance *queue,
 			   struct nfqnl_queue_entry *entry, int *errp)
 {
-	unsigned char *old_tail;
+	sk_buff_data_t old_tail;
 	size_t size;
 	size_t data_len = 0;
 	struct sk_buff *skb;
···
 	if (!skb)
 		goto nlmsg_failure;
 
-	old_tail= skb->tail;
+	old_tail = skb->tail;
 	nlh = NLMSG_PUT(skb, 0, 0,
 			NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET,
 			sizeof(struct nfgenmsg));

net/netlink/af_netlink.c

···
 
 	skb_orphan(skb);
 
-	delta = skb->end - skb->tail;
+	delta = skb->end - skb_tail_pointer(skb);
 	if (delta * 2 < skb->truesize)
 		return skb;
 

net/packet/af_packet.c

···
 		err = -EINVAL;
 		res = dev->hard_header(skb, dev, ntohs(proto), addr, NULL, len);
 		if (sock->type != SOCK_DGRAM) {
-			skb->tail = skb->data;
+			skb_reset_tail_pointer(skb);
 			skb->len = 0;
 		} else if (res < 0)
 			goto out_free;

net/sched/act_api.c

···
 				continue;
 			a->priv = p;
 			a->order = n_i;
-			r = (struct rtattr*) skb->tail;
+			r = (struct rtattr *)skb_tail_pointer(skb);
 			RTA_PUT(skb, a->order, 0, NULL);
 			err = tcf_action_dump_1(skb, a, 0, 0);
 			if (err < 0) {
···
 				skb_trim(skb, (u8*)r - skb->data);
 				goto done;
 			}
-			r->rta_len = skb->tail - (u8*)r;
+			r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 			n_i++;
 			if (n_i >= TCA_ACT_MAX_PRIO)
 				goto done;
···
 	struct rtattr *r ;
 	int i= 0, n_i = 0;
 
-	r = (struct rtattr*) skb->tail;
+	r = (struct rtattr *)skb_tail_pointer(skb);
 	RTA_PUT(skb, a->order, 0, NULL);
 	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 	for (i = 0; i < (hinfo->hmask + 1); i++) {
···
 		}
 	}
 	RTA_PUT(skb, TCA_FCNT, 4, &n_i);
-	r->rta_len = skb->tail - (u8*)r;
+	r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 
 	return n_i;
 rtattr_failure:
···
 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 {
 	int err = -EINVAL;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *r;
 
 	if (a->ops == NULL || a->ops->dump == NULL)
···
 	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
 	if (tcf_action_copy_stats(skb, a, 0))
 		goto rtattr_failure;
-	r = (struct rtattr*) skb->tail;
+	r = (struct rtattr *)skb_tail_pointer(skb);
 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 	if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
-		r->rta_len = skb->tail - (u8*)r;
+		r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 		return err;
 	}
 
···
 {
 	struct tc_action *a;
 	int err = -EINVAL;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *r ;
 
 	while ((a = act) != NULL) {
-		r = (struct rtattr*) skb->tail;
+		r = (struct rtattr *)skb_tail_pointer(skb);
 		act = a->next;
 		RTA_PUT(skb, a->order, 0, NULL);
 		err = tcf_action_dump_1(skb, a, bind, ref);
 		if (err < 0)
 			goto errout;
-		r->rta_len = skb->tail - (u8*)r;
+		r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 	}
 
 	return 0;
···
 {
 	struct tcamsg *t;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *x;
 
 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
···
 	t->tca__pad1 = 0;
 	t->tca__pad2 = 0;
 
-	x = (struct rtattr*) skb->tail;
+	x = (struct rtattr *)skb_tail_pointer(skb);
 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 
 	if (tcf_action_dump(skb, a, bind, ref) < 0)
 		goto rtattr_failure;
 
-	x->rta_len = skb->tail - (u8*)x;
+	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:
···
 		return -ENOBUFS;
 	}
 
-	b = (unsigned char *)skb->tail;
+	b = skb_tail_pointer(skb);
 
 	if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
 		goto err_out;
···
 	t->tca__pad1 = 0;
 	t->tca__pad2 = 0;
 
-	x = (struct rtattr *) skb->tail;
+	x = (struct rtattr *)skb_tail_pointer(skb);
 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 
 	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
 	if (err < 0)
 		goto rtattr_failure;
 
-	x->rta_len = skb->tail - (u8 *) x;
+	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	nlh->nlmsg_flags |= NLM_F_ROOT;
 	module_put(a->ops->owner);
 	kfree(a);
···
 	if (!skb)
 		return -ENOBUFS;
 
-	b = (unsigned char *)skb->tail;
+	b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
 	t = NLMSG_DATA(nlh);
···
 	t->tca__pad1 = 0;
 	t->tca__pad2 = 0;
 
-	x = (struct rtattr*) skb->tail;
+	x = (struct rtattr *)skb_tail_pointer(skb);
 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 
 	if (tcf_action_dump(skb, a, 0, 0) < 0)
 		goto rtattr_failure;
 
-	x->rta_len = skb->tail - (u8*)x;
+	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	NETLINK_CB(skb).dst_group = RTNLGRP_TC;
 
 	err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
···
 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *x;
 	struct tc_action_ops *a_o;
 	struct tc_action a;
···
 	t->tca__pad1 = 0;
 	t->tca__pad2 = 0;
 
-	x = (struct rtattr *) skb->tail;
+	x = (struct rtattr *)skb_tail_pointer(skb);
 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
 
 	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
···
 		goto rtattr_failure;
 
 	if (ret > 0) {
-		x->rta_len = skb->tail - (u8 *) x;
+		x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
 		ret = skb->len;
 	} else
 		skb_trim(skb, (u8*)x - skb->data);
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	if (NETLINK_CB(cb->skb).pid && ret)
 		nlh->nlmsg_flags |= NLM_F_MULTI;
 	module_put(a_o->owner);

net/sched/act_gact.c

···
 
 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 {
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_gact opt;
 	struct tcf_gact *gact = a->priv;
 	struct tcf_t t;

net/sched/act_ipt.c

···
 
 static int tcf_ipt_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 {
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_ipt *ipt = a->priv;
 	struct ipt_entry_target *t;
 	struct tcf_t tm;

net/sched/act_mirred.c

···
 
 static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 {
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_mirred *m = a->priv;
 	struct tc_mirred opt;
 	struct tcf_t t;

net/sched/act_pedit.c

···
 static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
 			  int bind, int ref)
 {
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_pedit *p = a->priv;
 	struct tc_pedit *opt;
 	struct tcf_t t;

net/sched/act_police.c

···
 				continue;
 			a->priv = p;
 			a->order = index;
-			r = (struct rtattr*) skb->tail;
+			r = (struct rtattr *)skb_tail_pointer(skb);
 			RTA_PUT(skb, a->order, 0, NULL);
 			if (type == RTM_DELACTION)
 				err = tcf_action_dump_1(skb, a, 0, 1);
···
 				skb_trim(skb, (u8*)r - skb->data);
 				goto done;
 			}
-			r->rta_len = skb->tail - (u8*)r;
+			r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
 			n_i++;
 		}
 	}
···
 static int
 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 {
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_police *police = a->priv;
 	struct tc_police opt;
 
···
 
 int tcf_police_dump(struct sk_buff *skb, struct tcf_police *police)
 {
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_police opt;
 
 	opt.index = police->tcf_index;

net/sched/act_simple.c

···
 static inline int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
 				int bind, int ref)
 {
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_defact *d = a->priv;
 	struct tc_defact opt;
 	struct tcf_t t;

net/sched/cls_api.c

···
 {
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
 	tcm = NLMSG_DATA(nlh);
···
 		if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
 			goto rtattr_failure;
 	}
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:
···
 		 * to work with both old and new modes of entering
 		 * tc data even if iproute2  was newer - jhs
 		 */
-		struct rtattr * p_rta = (struct rtattr*) skb->tail;
+		struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb);
 
 		if (exts->action->type != TCA_OLD_COMPAT) {
 			RTA_PUT(skb, map->action, 0, NULL);
 			if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
 				goto rtattr_failure;
-			p_rta->rta_len = skb->tail - (u8*)p_rta;
+			p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
 		} else if (map->police) {
 			RTA_PUT(skb, map->police, 0, NULL);
 			if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
 				goto rtattr_failure;
-			p_rta->rta_len = skb->tail - (u8*)p_rta;
+			p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
 		}
 	}
 #elif defined CONFIG_NET_CLS_POLICE
 	if (map->police && exts->police) {
-		struct rtattr * p_rta = (struct rtattr*) skb->tail;
+		struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb);
 
 		RTA_PUT(skb, map->police, 0, NULL);
 
 		if (tcf_police_dump(skb, exts->police) < 0)
 			goto rtattr_failure;
 
-		p_rta->rta_len = skb->tail - (u8*)p_rta;
+		p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta;
 	}
 #endif
 	return 0;

net/sched/cls_basic.c

···
 		      struct sk_buff *skb, struct tcmsg *t)
 {
 	struct basic_filter *f = (struct basic_filter *) fh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	if (f == NULL)
···
 	    tcf_em_tree_dump(skb, &f->ematches, TCA_BASIC_EMATCHES) < 0)
 		goto rtattr_failure;
 
-	rta->rta_len = (skb->tail - b);
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:

net/sched/cls_fw.c

···
 {
 	struct fw_head *head = (struct fw_head *)tp->root;
 	struct fw_filter *f = (struct fw_filter*)fh;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	if (f == NULL)
···
 	if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0)
 		goto rtattr_failure;
 
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 
 	if (tcf_exts_dump_stats(skb, &f->exts, &fw_ext_map) < 0)
 		goto rtattr_failure;

net/sched/cls_route.c

···
 		       struct sk_buff *skb, struct tcmsg *t)
 {
 	struct route4_filter *f = (struct route4_filter*)fh;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 	u32 id;
 
···
 	if (tcf_exts_dump(skb, &f->exts, &route_ext_map) < 0)
 		goto rtattr_failure;
 
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 
 	if (tcf_exts_dump_stats(skb, &f->exts, &route_ext_map) < 0)
 		goto rtattr_failure;

net/sched/cls_rsvp.h

···
 {
 	struct rsvp_filter *f = (struct rsvp_filter*)fh;
 	struct rsvp_session *s;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 	struct tc_rsvp_pinfo pinfo;
 
···
 	if (tcf_exts_dump(skb, &f->exts, &rsvp_ext_map) < 0)
 		goto rtattr_failure;
 
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 
 	if (tcf_exts_dump_stats(skb, &f->exts, &rsvp_ext_map) < 0)
 		goto rtattr_failure;

net/sched/cls_tcindex.c

···
 {
 	struct tcindex_data *p = PRIV(tp);
 	struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	DPRINTK("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
···
 		RTA_PUT(skb,TCA_TCINDEX_SHIFT,sizeof(p->shift),&p->shift);
 		RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through),
 		    &p->fall_through);
-		rta->rta_len = skb->tail-b;
+		rta->rta_len = skb_tail_pointer(skb) - b;
 	} else {
 		if (p->perfect) {
 			t->tcm_handle = r-p->perfect;
···
 
 		if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
 			goto rtattr_failure;
-		rta->rta_len = skb->tail-b;
+		rta->rta_len = skb_tail_pointer(skb) - b;
 
 		if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
 			goto rtattr_failure;

net/sched/cls_u32.c

···
 			off2 = 0;
 		}
 
-		if (ptr < skb->tail)
+		if (ptr < skb_tail_pointer(skb))
 			goto next_ht;
 	}
 
···
 		     struct sk_buff *skb, struct tcmsg *t)
 {
 	struct tc_u_knode *n = (struct tc_u_knode*)fh;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	if (n == NULL)
···
 #endif
 	}
 
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	if (TC_U32_KEY(n->handle))
 		if (tcf_exts_dump_stats(skb, &n->exts, &u32_ext_map) < 0)
 			goto rtattr_failure;

net/sched/ematch.c

···
 int tcf_em_tree_dump(struct sk_buff *skb, struct tcf_ematch_tree *tree, int tlv)
 {
 	int i;
-	struct rtattr * top_start = (struct rtattr*) skb->tail;
-	struct rtattr * list_start;
+	u8 *tail;
+	struct rtattr *top_start = (struct rtattr *)skb_tail_pointer(skb);
+	struct rtattr *list_start;
 
 	RTA_PUT(skb, tlv, 0, NULL);
 	RTA_PUT(skb, TCA_EMATCH_TREE_HDR, sizeof(tree->hdr), &tree->hdr);
 
-	list_start = (struct rtattr *) skb->tail;
+	list_start = (struct rtattr *)skb_tail_pointer(skb);
 	RTA_PUT(skb, TCA_EMATCH_TREE_LIST, 0, NULL);
 
+	tail = skb_tail_pointer(skb);
 	for (i = 0; i < tree->hdr.nmatches; i++) {
-		struct rtattr *match_start = (struct rtattr*) skb->tail;
+		struct rtattr *match_start = (struct rtattr *)tail;
 		struct tcf_ematch *em = tcf_em_get_match(tree, i);
 		struct tcf_ematch_hdr em_hdr = {
 			.kind = em->ops ? em->ops->kind : TCF_EM_CONTAINER,
···
 		} else if (em->datalen > 0)
 			RTA_PUT_NOHDR(skb, em->datalen, (void *) em->data);
 
-		match_start->rta_len = skb->tail - (u8*) match_start;
+		tail = skb_tail_pointer(skb);
+		match_start->rta_len = tail - (u8 *)match_start;
 	}
 
-	list_start->rta_len = skb->tail - (u8 *) list_start;
-	top_start->rta_len = skb->tail - (u8 *) top_start;
+	list_start->rta_len = tail - (u8 *)list_start;
+	top_start->rta_len = tail - (u8 *)top_start;
 
 	return 0;
 

net/sched/sch_api.c

···
 {
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct gnet_dump d;
 
 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
···
 	if (gnet_stats_finish_copy(&d) < 0)
 		goto rtattr_failure;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:
···
 {
 	struct tcmsg *tcm;
 	struct nlmsghdr  *nlh;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct gnet_dump d;
 	struct Qdisc_class_ops *cl_ops = q->ops->cl_ops;
 
···
 	if (gnet_stats_finish_copy(&d) < 0)
 		goto rtattr_failure;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:

net/sched/sch_atm.c

···
 {
 	struct atm_qdisc_data *p = PRIV(sch);
 	struct atm_flow_data *flow = (struct atm_flow_data *) cl;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	DPRINTK("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)\n",
···
 
 		RTA_PUT(skb,TCA_ATM_EXCESS,sizeof(zero),&zero);
 	}
-	rta->rta_len = skb->tail-b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:

net/sched/sch_cbq.c

···
 
 static __inline__ int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl)
 {
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	RTA_PUT(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate);
 	return skb->len;
···
 
 static __inline__ int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl)
 {
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_cbq_lssopt opt;
 
 	opt.flags = 0;
···
 
 static __inline__ int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl)
 {
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_cbq_wrropt opt;
 
 	opt.flags = 0;
···
 
 static __inline__ int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl)
 {
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_cbq_ovl opt;
 
 	opt.strategy = cl->ovl_strategy;
···
 
 static __inline__ int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
 {
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_cbq_fopt opt;
 
 	if (cl->split || cl->defmap) {
···
 #ifdef CONFIG_NET_CLS_POLICE
 static __inline__ int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl)
 {
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_cbq_police opt;
 
 	if (cl->police) {
···
 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct cbq_sched_data *q = qdisc_priv(sch);
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	rta = (struct rtattr*)b;
 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 	if (cbq_dump_attr(skb, &q->link) < 0)
 		goto rtattr_failure;
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:
···
 	       struct sk_buff *skb, struct tcmsg *tcm)
 {
 	struct cbq_class *cl = (struct cbq_class*)arg;
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	if (cl->tparent)
···
 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 	if (cbq_dump_attr(skb, cl) < 0)
 		goto rtattr_failure;
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:

net/sched/sch_hfsc.c

···
 		struct tcmsg *tcm)
 {
 	struct hfsc_class *cl = (struct hfsc_class *)arg;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta = (struct rtattr *)b;
 
 	tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->classid : TC_H_ROOT;
···
 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 	if (hfsc_dump_curves(skb, cl) < 0)
 		goto rtattr_failure;
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
  rtattr_failure:
···
 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct hfsc_sched *q = qdisc_priv(sch);
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_hfsc_qopt qopt;
 
 	qopt.defcls = q->defcls;

net/sched/sch_htb.c

···
 static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct htb_sched *q = qdisc_priv(sch);
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 	struct tc_htb_glob gopt;
 	spin_lock_bh(&sch->dev->queue_lock);
···
 	rta = (struct rtattr *)b;
 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
 	RTA_PUT(skb, TCA_HTB_INIT, sizeof(gopt), &gopt);
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	spin_unlock_bh(&sch->dev->queue_lock);
 	return skb->len;
 rtattr_failure:
 	spin_unlock_bh(&sch->dev->queue_lock);
-	skb_trim(skb, skb->tail - skb->data);
+	skb_trim(skb, skb_tail_pointer(skb) - skb->data);
 	return -1;
 }
 
···
 			  struct sk_buff *skb, struct tcmsg *tcm)
 {
 	struct htb_class *cl = (struct htb_class *)arg;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 	struct tc_htb_opt opt;
 
···
 	opt.prio = cl->un.leaf.prio;
 	opt.level = cl->level;
 	RTA_PUT(skb, TCA_HTB_PARMS, sizeof(opt), &opt);
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	spin_unlock_bh(&sch->dev->queue_lock);
 	return skb->len;
 rtattr_failure:

net/sched/sch_ingress.c

···
 
 static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 
 	rta = (struct rtattr *) b;
 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:

net/sched/sch_netem.c

···
 static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	const struct netem_sched_data *q = qdisc_priv(sch);
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta = (struct rtattr *) b;
 	struct tc_netem_qopt qopt;
 	struct tc_netem_corr cor;
···
 	corrupt.correlation = q->corrupt_cor.rho;
 	RTA_PUT(skb, TCA_NETEM_CORRUPT, sizeof(corrupt), &corrupt);
 
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 
 	return skb->len;
 

net/sched/sch_prio.c

···
 static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct prio_sched_data *q = qdisc_priv(sch);
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_prio_qopt opt;
 
 	opt.bands = q->bands;

net/sched/sch_sfq.c

···
 static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct sfq_sched_data *q = qdisc_priv(sch);
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct tc_sfq_qopt opt;
 
 	opt.quantum = q->quantum;

net/sched/sch_tbf.c

···
 static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct tbf_sched_data *q = qdisc_priv(sch);
-	unsigned char	 *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	struct rtattr *rta;
 	struct tc_tbf_qopt opt;
 
···
 	opt.mtu = q->mtu;
 	opt.buffer = q->buffer;
 	RTA_PUT(skb, TCA_TBF_PARMS, sizeof(opt), &opt);
-	rta->rta_len = skb->tail - b;
+	rta->rta_len = skb_tail_pointer(skb) - b;
 
 	return skb->len;
 

net/sctp/input.c

···
 			break;
 
 		ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
-		if (ch_end > skb->tail)
+		if (ch_end > skb_tail_pointer(skb))
 			break;
 
 		/* RFC 8.4, 2) If the OOTB packet contains an ABORT chunk, the
···
 		}
 
 		ch = (sctp_chunkhdr_t *) ch_end;
-	} while (ch_end < skb->tail);
+	} while (ch_end < skb_tail_pointer(skb));
 
 	return 0;
 

net/sctp/inqueue.c

···
 	 * the skb->tail.
 	 */
 	if (unlikely(skb_is_nonlinear(chunk->skb))) {
-		if (chunk->chunk_end > chunk->skb->tail)
-			chunk->chunk_end = chunk->skb->tail;
+		if (chunk->chunk_end > skb_tail_pointer(chunk->skb))
+			chunk->chunk_end = skb_tail_pointer(chunk->skb);
 	}
 	skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
 	chunk->subh.v = NULL; /* Subheader is no longer valid.  */
 
-	if (chunk->chunk_end < chunk->skb->tail) {
+	if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) {
 		/* This is not a singleton */
 		chunk->singleton = 0;
-	} else if (chunk->chunk_end > chunk->skb->tail) {
+	} else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
 		/* RFC 2960, Section 6.10  Bundling
 		 *
 		 * Partial chunks MUST NOT be placed in an SCTP packet.

net/sctp/sm_make_chunk.c

···
 
 	/* Adjust the chunk length field.  */
 	chunk->chunk_hdr->length = htons(chunklen + padlen + len);
-	chunk->chunk_end = chunk->skb->tail;
+	chunk->chunk_end = skb_tail_pointer(chunk->skb);
 
 	return target;
 }
···
 	/* Adjust the chunk length field.  */
 	chunk->chunk_hdr->length =
 		htons(ntohs(chunk->chunk_hdr->length) + len);
-	chunk->chunk_end = chunk->skb->tail;
+	chunk->chunk_end = skb_tail_pointer(chunk->skb);
 
 out:
 	return err;

net/sctp/sm_statefuns.c

···
 			break;
 
 		ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
-		if (ch_end > skb->tail)
+		if (ch_end > skb_tail_pointer(skb))
 			break;
 
 		if (SCTP_CID_SHUTDOWN_ACK == ch->type)
···
 			return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
 
 		ch = (sctp_chunkhdr_t *) ch_end;
-	} while (ch_end < skb->tail);
+	} while (ch_end < skb_tail_pointer(skb));
 
 	if (ootb_shut_ack)
 		sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);

net/tipc/config.c

···
 int tipc_cfg_append_tlv(struct sk_buff *buf, int tlv_type,
 			void *tlv_data, int tlv_data_size)
 {
-	struct tlv_desc *tlv = (struct tlv_desc *)buf->tail;
+	struct tlv_desc *tlv = (struct tlv_desc *)skb_tail_pointer(buf);
 	int new_tlv_space = TLV_SPACE(tlv_data_size);
 
 	if (skb_tailroom(buf) < new_tlv_space) {

net/tipc/socket.c

···
 
 	if (!err) {
 		buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
-		sz = buf->tail - buf_crs;
+		sz = skb_tail_pointer(buf) - buf_crs;
 
 		needed = (buf_len - sz_copied);
 		sz_to_copy = (sz <= needed) ? sz : needed;

net/xfrm/xfrm_user.c

···
 	struct sk_buff *skb = sp->out_skb;
 	struct xfrm_usersa_info *p;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	if (sp->this_idx < sp->start_idx)
 		goto out;
···
 	if (x->lastused)
 		RTA_PUT(skb, XFRMA_LASTUSED, sizeof(x->lastused), &x->lastused);
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 out:
 	sp->this_idx++;
 	return 0;
···
 	struct sk_buff *in_skb = sp->in_skb;
 	struct sk_buff *skb = sp->out_skb;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	if (sp->this_idx < sp->start_idx)
 		goto out;
···
 	if (copy_to_user_policy_type(xp->type, skb) < 0)
 		goto nlmsg_failure;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 out:
 	sp->this_idx++;
 	return 0;
···
 	struct xfrm_aevent_id *id;
 	struct nlmsghdr *nlh;
 	struct xfrm_lifetime_cur ltime;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_PUT(skb, c->pid, c->seq, XFRM_MSG_NEWAE, sizeof(*id));
 	id = NLMSG_DATA(nlh);
···
 		RTA_PUT(skb,XFRMA_ETIMER_THRESH,sizeof(u32),&etimer);
 	}
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 rtattr_failure:
···
 	struct xfrm_migrate *mp;
 	struct xfrm_userpolicy_id *pol_id;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	int i;
 
 	nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_MIGRATE, sizeof(*pol_id));
···
 			goto nlmsg_failure;
 	}
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 nlmsg_failure:
 	skb_trim(skb, b - skb->data);
···
 {
 	struct xfrm_user_expire *ue;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_PUT(skb, c->pid, 0, XFRM_MSG_EXPIRE,
 			sizeof(*ue));
···
 	copy_to_user_state(x, &ue->state);
 	ue->hard = (c->data.hard != 0) ? 1 : 0;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:
···
 	struct xfrm_usersa_flush *p;
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;
-	unsigned char *b;
+	sk_buff_data_t b;
 	int len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_flush));
 
 	skb = alloc_skb(len, GFP_ATOMIC);
···
 	struct xfrm_usersa_id *id;
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;
-	unsigned char *b;
+	sk_buff_data_t b;
 	int len = xfrm_sa_len(x);
 	int headlen;
 
···
 {
 	struct xfrm_user_acquire *ua;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 	__u32 seq = xfrm_get_acqseq();
 
 	nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_ACQUIRE,
···
 	if (copy_to_user_policy_type(xp->type, skb) < 0)
 		goto nlmsg_failure;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:
···
 	struct xfrm_user_polexpire *upe;
 	struct nlmsghdr *nlh;
 	int hard = c->data.hard;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_PUT(skb, c->pid, 0, XFRM_MSG_POLEXPIRE, sizeof(*upe));
 	upe = NLMSG_DATA(nlh);
···
 		goto nlmsg_failure;
 	upe->hard = !!hard;
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:
···
 	struct xfrm_userpolicy_id *id;
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;
-	unsigned char *b;
+	sk_buff_data_t b;
 	int len = RTA_SPACE(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
 	int headlen;
 
···
 {
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;
-	unsigned char *b;
+	sk_buff_data_t b;
 	int len = 0;
 #ifdef CONFIG_XFRM_SUB_POLICY
 	len += RTA_SPACE(sizeof(struct xfrm_userpolicy_type));
···
 {
 	struct xfrm_user_report *ur;
 	struct nlmsghdr *nlh;
-	unsigned char *b = skb->tail;
+	unsigned char *b = skb_tail_pointer(skb);
 
 	nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_REPORT, sizeof(*ur));
 	ur = NLMSG_DATA(nlh);
···
 	if (addr)
 		RTA_PUT(skb, XFRMA_COADDR, sizeof(*addr), addr);
 
-	nlh->nlmsg_len = skb->tail - b;
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
 	return skb->len;
 
 nlmsg_failure:

security/selinux/netlink.c

···
 static void selnl_notify(int msgtype, void *data)
 {
 	int len;
-	unsigned char *tmp;
+	sk_buff_data_t tmp;
 	struct sk_buff *skb;
 	struct nlmsghdr *nlh;