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: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 661e9dd..a46c267 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -4552,6 +4552,12 @@
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 @@
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 @@
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));