Commit e92967bf authored by Matt Carlson's avatar Matt Carlson Committed by David S. Miller
Browse files

tg3: Prevent rx producer ring overruns 



When operating in RSS mode, it is possible for one rx return ring to
submit enough rx buffers back to the hardware such that it inadvertently
overwrites data needed by another rx return ring.  This patch addresses
the problem by looking for non-NULL skb pointers in the
rx_[std|jmb]_buffers rings that parallel the rx producer rings.

Signed-off-by: default avatarMatt Carlson <mcarlson@broadcom.com>
Signed-off-by: default avatarMichael Chan <mchan@broadcom.com>
Reviewed-by: default avatarBenjamin Li <benli@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e4af1af9

drivers/net/tg3.c

+38 −0
Original line number Diff line number Diff line
@@ -4552,6 +4552,12 @@ static void tg3_recycle_rx(struct tg3_napi *tnapi, 
			   pci_unmap_addr(src_map, mapping));

	dest_desc->addr_hi = src_desc->addr_hi;

	dest_desc->addr_lo = src_desc->addr_lo;



	/* Ensure that the update to the skb happens after the physical

	 * addresses have been transferred to the new BD location.

	 */

	smp_wmb();



	src_map->skb = NULL;

}
@@ -4816,6 +4822,22 @@ static void tg3_rx_prodring_xfer(struct tg3 *tp, 
		si = spr->rx_std_cons_idx;

		di = dpr->rx_std_prod_idx;



		for (i = di; i < di + cpycnt; i++) {

			if (dpr->rx_std_buffers[i].skb) {

				cpycnt = i - di;

				break;

			}

		}



		if (!cpycnt)

			break;



		/* Ensure that updates to the rx_std_buffers ring and the

		 * shadowed hardware producer ring from tg3_recycle_skb() are

		 * ordered correctly WRT the skb check above.

		 */

		smp_rmb();



		memcpy(&dpr->rx_std_buffers[di],

		       &spr->rx_std_buffers[si],

		       cpycnt * sizeof(struct ring_info));
@@ -4856,6 +4878,22 @@ static void tg3_rx_prodring_xfer(struct tg3 *tp, 
		si = spr->rx_jmb_cons_idx;

		di = dpr->rx_jmb_prod_idx;



		for (i = di; i < di + cpycnt; i++) {

			if (dpr->rx_jmb_buffers[i].skb) {

				cpycnt = i - di;

				break;

			}

		}



		if (!cpycnt)

			break;



		/* Ensure that updates to the rx_jmb_buffers ring and the

		 * shadowed hardware producer ring from tg3_recycle_skb() are

		 * ordered correctly WRT the skb check above.

		 */

		smp_rmb();



		memcpy(&dpr->rx_jmb_buffers[di],

		       &spr->rx_jmb_buffers[si],

		       cpycnt * sizeof(struct ring_info));

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