From 4237be2b9e250d431d465b81a0abbe5fb559d2c8 Mon Sep 17 00:00:00 2001 From: Jeff Guo Date: Thu, 16 Jul 2020 17:24:38 +0800 Subject: [PATCH] net/e1000: fix crash on Tx done clean up As tx mbuf is not set for some advanced descriptors, if there is no mbuf checking before rte_pktmbuf_free_seg() function be called on the process of tx done clean up, that will cause a segfault. So add a NULL pointer check to fix it. Bugzilla ID: 501 Fixes: 8d907d2b79f7 ("net/igb: free consumed Tx buffers on demand") Cc: stable@dpdk.org Signed-off-by: Jeff Guo Reviewed-by: Wei Zhao --- drivers/net/e1000/igb_rxtx.c | 170 +++++++++++++++++------------------ 1 file changed, 82 insertions(+), 88 deletions(-) diff --git a/drivers/net/e1000/igb_rxtx.c b/drivers/net/e1000/igb_rxtx.c index 6411924e03..dd520cd82c 100644 --- a/drivers/net/e1000/igb_rxtx.c +++ b/drivers/net/e1000/igb_rxtx.c @@ -1295,113 +1295,107 @@ igb_tx_done_cleanup(struct igb_tx_queue *txq, uint32_t free_cnt) uint16_t tx_id; /* Current segment being processed. */ uint16_t tx_last; /* Last segment in the current packet. */ uint16_t tx_next; /* First segment of the next packet. */ - int count; + int count = 0; - if (txq != NULL) { - count = 0; - sw_ring = txq->sw_ring; - txr = txq->tx_ring; + if (!txq) + return -ENODEV; - /* - * tx_tail is the last sent packet on the sw_ring. Goto the end - * of that packet (the last segment in the packet chain) and - * then the next segment will be the start of the oldest segment - * in the sw_ring. This is the first packet that will be - * attempted to be freed. - */ + sw_ring = txq->sw_ring; + txr = txq->tx_ring; - /* Get last segment in most recently added packet. */ - tx_first = sw_ring[txq->tx_tail].last_id; + /* tx_tail is the last sent packet on the sw_ring. Goto the end + * of that packet (the last segment in the packet chain) and + * then the next segment will be the start of the oldest segment + * in the sw_ring. This is the first packet that will be + * attempted to be freed. + */ - /* Get the next segment, which is the oldest segment in ring. */ - tx_first = sw_ring[tx_first].next_id; + /* Get last segment in most recently added packet. */ + tx_first = sw_ring[txq->tx_tail].last_id; - /* Set the current index to the first. */ - tx_id = tx_first; + /* Get the next segment, which is the oldest segment in ring. */ + tx_first = sw_ring[tx_first].next_id; - /* - * Loop through each packet. For each packet, verify that an - * mbuf exists and that the last segment is free. If so, free - * it and move on. - */ - while (1) { - tx_last = sw_ring[tx_id].last_id; - - if (sw_ring[tx_last].mbuf) { - if (txr[tx_last].wb.status & - E1000_TXD_STAT_DD) { - /* - * Increment the number of packets - * freed. - */ - count++; - - /* Get the start of the next packet. */ - tx_next = sw_ring[tx_last].next_id; - - /* - * Loop through all segments in a - * packet. - */ - do { - rte_pktmbuf_free_seg(sw_ring[tx_id].mbuf); + /* Set the current index to the first. */ + tx_id = tx_first; + + /* Loop through each packet. For each packet, verify that an + * mbuf exists and that the last segment is free. If so, free + * it and move on. + */ + while (1) { + tx_last = sw_ring[tx_id].last_id; + + if (sw_ring[tx_last].mbuf) { + if (txr[tx_last].wb.status & + E1000_TXD_STAT_DD) { + /* Increment the number of packets + * freed. + */ + count++; + + /* Get the start of the next packet. */ + tx_next = sw_ring[tx_last].next_id; + + /* Loop through all segments in a + * packet. + */ + do { + if (sw_ring[tx_id].mbuf) { + rte_pktmbuf_free_seg( + sw_ring[tx_id].mbuf); sw_ring[tx_id].mbuf = NULL; sw_ring[tx_id].last_id = tx_id; + } - /* Move to next segemnt. */ - tx_id = sw_ring[tx_id].next_id; + /* Move to next segemnt. */ + tx_id = sw_ring[tx_id].next_id; - } while (tx_id != tx_next); + } while (tx_id != tx_next); - if (unlikely(count == (int)free_cnt)) - break; - } else - /* - * mbuf still in use, nothing left to - * free. - */ + if (unlikely(count == (int)free_cnt)) break; } else { - /* - * There are multiple reasons to be here: - * 1) All the packets on the ring have been - * freed - tx_id is equal to tx_first - * and some packets have been freed. - * - Done, exit - * 2) Interfaces has not sent a rings worth of - * packets yet, so the segment after tail is - * still empty. Or a previous call to this - * function freed some of the segments but - * not all so there is a hole in the list. - * Hopefully this is a rare case. - * - Walk the list and find the next mbuf. If - * there isn't one, then done. + /* mbuf still in use, nothing left to + * free. */ - if (likely((tx_id == tx_first) && (count != 0))) - break; + break; + } + } else { + /* There are multiple reasons to be here: + * 1) All the packets on the ring have been + * freed - tx_id is equal to tx_first + * and some packets have been freed. + * - Done, exit + * 2) Interfaces has not sent a rings worth of + * packets yet, so the segment after tail is + * still empty. Or a previous call to this + * function freed some of the segments but + * not all so there is a hole in the list. + * Hopefully this is a rare case. + * - Walk the list and find the next mbuf. If + * there isn't one, then done. + */ + if (likely(tx_id == tx_first && count != 0)) + break; - /* - * Walk the list and find the next mbuf, if any. - */ - do { - /* Move to next segemnt. */ - tx_id = sw_ring[tx_id].next_id; + /* Walk the list and find the next mbuf, if any. */ + do { + /* Move to next segemnt. */ + tx_id = sw_ring[tx_id].next_id; - if (sw_ring[tx_id].mbuf) - break; + if (sw_ring[tx_id].mbuf) + break; - } while (tx_id != tx_first); + } while (tx_id != tx_first); - /* - * Determine why previous loop bailed. If there - * is not an mbuf, done. - */ - if (sw_ring[tx_id].mbuf == NULL) - break; - } + /* Determine why previous loop bailed. If there + * is not an mbuf, done. + */ + if (!sw_ring[tx_id].mbuf) + break; } - } else - count = -ENODEV; + } return count; } -- 2.20.1