diff options
| author | Julian Wiedmann <jwi@linux.ibm.com> | 2020-03-12 18:57:54 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-03-12 11:19:24 -0700 |
| commit | 7c4046b1c53bba3a0315f04bb0bb5f36888a747b (patch) | |
| tree | 21b3b5945a2311f163da59cd16377de8921f8b44 /net | |
| parent | e6e0f093d97872353bda8922456064dbcf5d82a2 (diff) | |
Revert "net: sched: make newly activated qdiscs visible"
This reverts commit 4cda75275f9f89f9485b0ca4d6950c95258a9bce
from net-next.
Brown bag time.
Michal noticed that this change doesn't work at all when
netif_set_real_num_tx_queues() gets called prior to an initial
dev_activate(), as for instance igb does.
Doing so dies with:
[ 40.579142] BUG: kernel NULL pointer dereference, address: 0000000000000400
[ 40.586922] #PF: supervisor read access in kernel mode
[ 40.592668] #PF: error_code(0x0000) - not-present page
[ 40.598405] PGD 0 P4D 0
[ 40.601234] Oops: 0000 [#1] PREEMPT SMP PTI
[ 40.605909] CPU: 18 PID: 1681 Comm: wickedd Tainted: G E 5.6.0-rc3-ethnl.50-default #1
[ 40.616205] Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.R3.27.D685.1305151734 05/15/2013
[ 40.627377] RIP: 0010:qdisc_hash_add.part.22+0x2e/0x90
[ 40.633115] Code: 00 55 53 89 f5 48 89 fb e8 2f 9b fb ff 85 c0 74 44 48 8b 43 40 48 8b 08 69 43 38 47 86 c8 61 c1 e8 1c 48 83 e8 80 48 8d 14 c1 <48> 8b 04 c1 48 8d 4b 28 48 89 53 30 48 89 43 28 48 85 c0 48 89 0a
[ 40.654080] RSP: 0018:ffffb879864934d8 EFLAGS: 00010203
[ 40.659914] RAX: 0000000000000080 RBX: ffffffffb8328d80 RCX: 0000000000000000
[ 40.667882] RDX: 0000000000000400 RSI: 0000000000000000 RDI: ffffffffb831faa0
[ 40.675849] RBP: 0000000000000000 R08: ffffa0752c8b9088 R09: ffffa0752c8b9208
[ 40.683816] R10: 0000000000000006 R11: 0000000000000000 R12: ffffa0752d734000
[ 40.691783] R13: 0000000000000008 R14: 0000000000000000 R15: ffffa07113c18000
[ 40.699750] FS: 00007f94548e5880(0000) GS:ffffa0752e980000(0000) knlGS:0000000000000000
[ 40.708782] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 40.715189] CR2: 0000000000000400 CR3: 000000082b6ae006 CR4: 00000000001606e0
[ 40.723156] Call Trace:
[ 40.725888] dev_qdisc_set_real_num_tx_queues+0x61/0x90
[ 40.731725] netif_set_real_num_tx_queues+0x94/0x1d0
[ 40.737286] __igb_open+0x19a/0x5d0 [igb]
[ 40.741767] __dev_open+0xbb/0x150
[ 40.745567] __dev_change_flags+0x157/0x1a0
[ 40.750240] dev_change_flags+0x23/0x60
[...]
Fixes: 4cda75275f9f ("net: sched: make newly activated qdiscs visible")
Reported-by: Michal Kubecek <mkubecek@suse.cz>
CC: Michal Kubecek <mkubecek@suse.cz>
CC: Eric Dumazet <edumazet@google.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
CC: Cong Wang <xiyou.wangcong@gmail.com>
CC: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev.c | 1 | ||||
| -rw-r--r-- | net/sched/sch_generic.c | 21 |
2 files changed, 0 insertions, 22 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index ccc03abeee52..25dab1598803 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2875,7 +2875,6 @@ int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq) netif_setup_tc(dev, txq); dev->real_num_tx_queues = txq; - dev_qdisc_set_real_num_tx_queues(dev); if (disabling) { synchronize_net(); diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 36a40ebcf0ee..6c9595f1048a 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1268,27 +1268,6 @@ int dev_qdisc_change_tx_queue_len(struct net_device *dev) return ret; } -void dev_qdisc_set_real_num_tx_queues(struct net_device *dev) -{ -#ifdef CONFIG_NET_SCHED - struct Qdisc *sch = dev->qdisc; - unsigned int ntx; - - if (!sch) - return; - - ASSERT_RTNL(); - - for (ntx = 0; ntx < dev->real_num_tx_queues; ntx++) { - struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx); - struct Qdisc *qdisc = dev_queue->qdisc; - - if (qdisc && !qdisc_hashed(qdisc)) - qdisc_hash_add(qdisc, false); - } -#endif -} - static void dev_init_scheduler_queue(struct net_device *dev, struct netdev_queue *dev_queue, void *_qdisc) |