From 550ecc92feb10fdb7ab1d052707b11bca955de5f Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Thu, 21 May 2015 12:40:16 +0900 Subject: [PATCH] rocker: do not make neighbour entry changes when preparing transactions rocker_port_ipv4_nh() and in turn rocker_port_ipv4_neigh() may be be called with trans == SWITCHDEV_TRANS_PREPARE and then trans == SWITCHDEV_TRANS_COMMIT from switchdev_port_obj_set() via fib_table_insert(). The first time that rocker_port_ipv4_nh() is called, with trans == SWITCHDEV_TRANS_PREPARE, _rocker_neigh_add() adds a new entry to the neigh table. And the second time rocker_port_ipv4_nh() is called, with trans == SWITCHDEV_TRANS_COMMIT, that entry is found. This causes rocker_port_ipv4_nh() to believe it is not adding an entry and thus it frees "entry", which is still present in rocker driver's neigh table. This problem does not appear to affect deletion as my analysis is that deletion is always performed with trans == SWITCHDEV_TRANS_NONE. For completeness _rocker_neigh_{add,del,prepare} are updated not to manipulate fib table entries if trans == SWITCHDEV_TRANS_PREPARE. Fixes: c4f20321d968 ("rocker: support prepare-commit transaction model") Reported-by: Toshiaki Makita Acked-by: Scott Feldman Acked-by: Jiri Pirko Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/rocker/rocker.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/rocker/rocker.c b/drivers/net/ethernet/rocker/rocker.c index 89d22bdcbdc4..51744764acd7 100644 --- a/drivers/net/ethernet/rocker/rocker.c +++ b/drivers/net/ethernet/rocker/rocker.c @@ -2909,9 +2909,13 @@ static struct rocker_neigh_tbl_entry * } static void _rocker_neigh_add(struct rocker *rocker, + enum switchdev_trans trans, struct rocker_neigh_tbl_entry *entry) { - entry->index = rocker->neigh_tbl_next_index++; + entry->index = rocker->neigh_tbl_next_index; + if (trans == SWITCHDEV_TRANS_PREPARE) + return; + rocker->neigh_tbl_next_index++; entry->ref_count++; hash_add(rocker->neigh_tbl, &entry->entry, be32_to_cpu(entry->ip_addr)); @@ -2921,6 +2925,8 @@ static void _rocker_neigh_del(struct rocker_port *rocker_port, enum switchdev_trans trans, struct rocker_neigh_tbl_entry *entry) { + if (trans == SWITCHDEV_TRANS_PREPARE) + return; if (--entry->ref_count == 0) { hash_del(&entry->entry); rocker_port_kfree(rocker_port, trans, entry); @@ -2928,12 +2934,13 @@ static void _rocker_neigh_del(struct rocker_port *rocker_port, } static void _rocker_neigh_update(struct rocker_neigh_tbl_entry *entry, + enum switchdev_trans trans, u8 *eth_dst, bool ttl_check) { if (eth_dst) { ether_addr_copy(entry->eth_dst, eth_dst); entry->ttl_check = ttl_check; - } else { + } else if (trans != SWITCHDEV_TRANS_PREPARE) { entry->ref_count++; } } @@ -2973,12 +2980,12 @@ static int rocker_port_ipv4_neigh(struct rocker_port *rocker_port, entry->dev = rocker_port->dev; ether_addr_copy(entry->eth_dst, eth_dst); entry->ttl_check = true; - _rocker_neigh_add(rocker, entry); + _rocker_neigh_add(rocker, trans, entry); } else if (removing) { memcpy(entry, found, sizeof(*entry)); _rocker_neigh_del(rocker_port, trans, found); } else if (updating) { - _rocker_neigh_update(found, eth_dst, true); + _rocker_neigh_update(found, trans, eth_dst, true); memcpy(entry, found, sizeof(*entry)); } else { err = -ENOENT; @@ -3089,13 +3096,13 @@ static int rocker_port_ipv4_nh(struct rocker_port *rocker_port, if (adding) { entry->ip_addr = ip_addr; entry->dev = rocker_port->dev; - _rocker_neigh_add(rocker, entry); + _rocker_neigh_add(rocker, trans, entry); *index = entry->index; resolved = false; } else if (removing) { _rocker_neigh_del(rocker_port, trans, found); } else if (updating) { - _rocker_neigh_update(found, NULL, false); + _rocker_neigh_update(found, trans, NULL, false); resolved = !is_zero_ether_addr(found->eth_dst); } else { err = -ENOENT;