From: Jiri Slaby <jslaby@suse•cz>
To: Jason Wang <jasowang@redhat•com>
Cc: "David S. Miller" <davem@davemloft•net>,
ML netdev <netdev@vger•kernel.org>,
LKML <linux-kernel@vger•kernel.org>,
rmilasan@suse•cz, Jiri Slaby <jirislaby@gmail•com>,
maxk@qualcomm•com, vtun@office•satix.net
Subject: Re: "tuntap: multiqueue support" causes udev fork bombs
Date: Fri, 30 Nov 2012 18:01:29 +0100 [thread overview]
Message-ID: <50B8E669.6040200@suse.cz> (raw)
In-Reply-To: <4146845.d5imC0scLB@jason-thinkpad-t430s>
On 11/29/2012 06:47 AM, Jason Wang wrote:
> On Wednesday, November 28, 2012 11:25:41 AM Jiri Slaby wrote:
>> Hi,
>>
>> with this commit:
>> commit c8d68e6be1c3b242f1c598595830890b65cea64a
>> Author: Jason Wang <jasowang@redhat•com>
>> Date: Wed Oct 31 19:46:00 2012 +0000
>>
>> tuntap: multiqueue support
>>
>>
>> I see fork bombs from udev. It is trying to create 2048 processes. 1024
>> for tx, 1024 for rx. OOM killer indeed steps in and kills everything.
>
> Hi, thanks for the reporting, could you pls try the following patch?
Hi, it is gone with this patch.
> ---
>
> diff --git a/drivers/net/tun.c b/drivers/net/tun.c
> index b44d7b7..cc3f878 100644
> --- a/drivers/net/tun.c
> +++ b/drivers/net/tun.c
> @@ -492,9 +492,6 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
>
> tun_set_real_num_queues(tun);
>
> - if (tun->numqueues == 1)
> - netif_carrier_on(tun->dev);
> -
> /* device is allowed to go away first, so no need to hold extra
> * refcnt.
> */
> @@ -1611,6 +1608,10 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
> TUN_USER_FEATURES;
> dev->features = dev->hw_features;
>
> + err = tun_attach(tun, file);
> + if (err < 0)
> + goto err_free_dev;
> +
> err = register_netdevice(tun->dev);
> if (err < 0)
> goto err_free_dev;
> @@ -1620,9 +1621,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
> device_create_file(&tun->dev->dev, &dev_attr_group))
> pr_err("Failed to create tun sysfs files\n");
>
> - err = tun_attach(tun, file);
> - if (err < 0)
> - goto err_free_dev;
> + netif_carrier_on(tun->dev);
> }
>
> tun_debug(KERN_INFO, tun, "tun_set_iff\n");
>
--
js
suse labs
prev parent reply other threads:[~2012-11-30 17:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-28 10:25 "tuntap: multiqueue support" causes udev fork bombs Jiri Slaby
2012-11-28 10:30 ` Robert Milasan
2012-11-28 15:25 ` David Miller
2012-11-29 5:47 ` Jason Wang
2012-11-30 17:01 ` Jiri Slaby [this message]
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