Linuxarm August 2021

linuxarm@openeuler.org

18 participants
28 discussions

MAILBOX SECURITY UPDATE
by ✉ openeuler.org 04 Aug '21

04 Aug '21

1 0

[PATCH V2 net-next] bonding: 3ad: fix the concurrency between __bond_release_one() and bond_3ad_state_machine_handler()
by Yufeng Mo 02 Aug '21

02 Aug '21

Some time ago, I reported a calltrace issue "did not find a suitable aggregator", please see[1]. After a period of analysis and reproduction, I find that this problem is caused by concurrency. Before the problem occurs, the bond structure is like follows: bond0 - slaver0(eth0) - agg0.lag_ports -> port0 - port1 \ port0 \ slaver1(eth1) - agg1.lag_ports -> NULL \ port1 If we run 'ifenslave bond0 -d eth1', the process is like below: excuting __bond_release_one() | bond_upper_dev_unlink()[step1] | | | | | bond_3ad_lacpdu_recv() | | ->bond_3ad_rx_indication() | | spin_lock_bh() | | ->ad_rx_machine() | | ->__record_pdu()[step2] | | spin_unlock_bh() | | | | bond_3ad_state_machine_handler() | spin_lock_bh() | ->ad_port_selection_logic() | ->try to find free aggregator[step3] | ->try to find suitable aggregator[step4] | ->did not find a suitable aggregator[step5] | spin_unlock_bh() | | | | bond_3ad_unbind_slave() | spin_lock_bh() spin_unlock_bh() step1: already removed slaver1(eth1) from list, but port1 remains step2: receive a lacpdu and update port0 step3: port0 will be removed from agg0.lag_ports. The struct is "agg0.lag_ports -> port1" now, and agg0 is not free. At the same time, slaver1/agg1 has been removed from the list by step1. So we can't find a free aggregator now. step4: can't find suitable aggregator because of step2 step5: cause a calltrace since port->aggregator is NULL To solve this concurrency problem, put bond_upper_dev_unlink() after bond_3ad_unbind_slave(). In this way, we can invalid the port first and skip this port in bond_3ad_state_machine_handler(). This eliminates the situation that the slaver has been removed from the list but the port is still valid. [1]https://lore.kernel.org/netdev/10374.1611947473@famine/ Signed-off-by: Yufeng Mo <moyufeng(a)huawei.com> Acked-by: Jay Vosburgh <jay.vosburgh(a)canonical.com> --- ChangeLogs: V1 -> V2: Modify the method of resolving concurrency because bond_upper_dev_unlink() may sleep and cannot hold mode lock. --- drivers/net/bonding/bond_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index d22d783..c23f39e 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -2252,7 +2252,6 @@ static int __bond_release_one(struct net_device *bond_dev, /* recompute stats just before removing the slave */ bond_get_stats(bond->dev, &bond->bond_stats); - bond_upper_dev_unlink(bond, slave); /* unregister rx_handler early so bond_handle_frame wouldn't be called * for this slave anymore. */ @@ -2261,6 +2260,8 @@ static int __bond_release_one(struct net_device *bond_dev, if (BOND_MODE(bond) == BOND_MODE_8023AD) bond_3ad_unbind_slave(slave); + bond_upper_dev_unlink(bond, slave); + if (bond_mode_can_use_xmit_hash(bond)) bond_update_slave_arr(bond, slave); -- 2.8.1

2 1

[PATCH rfc v6 0/4] add frag page support in page pool
by Yunsheng Lin 02 Aug '21

02 Aug '21

This patchset adds frag page support in page pool and enable skb's page frag recycling based on page pool in hns3 drvier. RFC v6: 1. Disable frag page support in system 32-bit arch and 64-bit DMA. RFC v5: 1. Rename dma_addr[0] to pp_frag_count and adjust codes according to the rename. RFC v4: 1. Use the dma_addr[1] to store bias. 2. Default to a pagecnt_bias of PAGE_SIZE - 1. 3. other minor comment suggested by Alexander. RFC v3: 1. Implement the semantic of "page recycling only wait for the page pool user instead of all user of a page" 2. Support the frag allocation of different sizes 3. Merge patch 4 & 5 to one patch as it does not make sense to use page_pool_dev_alloc_pages() API directly with elevated refcnt. 4. other minor comment suggested by Alexander. RFC v2: 1. Split patch 1 to more reviewable one. 2. Repurpose the lower 12 bits of the dma address to store the pagecnt_bias as suggested by Alexander. 3. support recycling to pool->alloc for elevated refcnt case too. Yunsheng Lin (4): page_pool: keep pp info as long as page pool owns the page page_pool: add interface to manipulate frag count in page pool page_pool: add frag page recycling support in page pool net: hns3: support skb's frag page recycling based on page pool drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 82 +++++++++++++++-- drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 3 + drivers/net/ethernet/marvell/mvneta.c | 6 +- drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 2 +- drivers/net/ethernet/ti/cpsw.c | 2 +- drivers/net/ethernet/ti/cpsw_new.c | 2 +- include/linux/mm_types.h | 18 ++-- include/linux/skbuff.h | 4 +- include/net/page_pool.h | 65 +++++++++++--- net/core/page_pool.c | 112 +++++++++++++++++++++++- 10 files changed, 257 insertions(+), 39 deletions(-) -- 2.7.4

3 16

2024

2023

2022

2021

2020

Linuxarm August 2021