[Click] kernel panic on using FromHost

[Shoban]

Hi,

I am trying to run click in kernel mode in Xen paravirtualized VM. When using
a simple click config[2] using FromHost, there is a kernel panic[1].
The config loads
fine the first time, but on click-uninstall and click-install it fails.

This happens in both click-2.0.1 and latest click github clone. I am using
linux 2.6.38.12 in patchless mode.

Any help would be much appreciated.

Thanks,
Shoban

--
[1] Kernel panic log (full log at https://gist.github.com/3741589)

[  136.891896] click module exiting
[  142.849335] BUG: unable to handle kernel NULL pointer dereference at (null)
[  142.849350] IP: [<(null)>] (null)
[  142.849356] PGD 0
[  142.849361] Oops: 0010 [#1] SMP
[  142.849367] last sysfs file: /sys/devices/virtual/net/fake0/uevent
[  142.849374] CPU 0
[  142.849377] Modules linked in: click proclikefs nfsd exportfs nfs
lockd fscache nfs_acl auth_rpcgss sunrpc lp parport [last unloaded:
click]
...
[  142.849537] Call Trace:
[  142.849541]  <IRQ>
[  142.849551]  [<ffffffff81465fee>] ? netif_receive_skb+0x1ee/0x640
[  142.849560]  [<ffffffff810316de>] ? pvclock_clocksource_read+0x4e/0x100
[  142.849569]  [<ffffffff813c7d4c>] xennet_poll+0x5ec/0xdd0
[  142.849576]  [<ffffffff81467152>] net_rx_action+0x122/0x240
[  142.849585]  [<ffffffff81063967>] __do_softirq+0xb7/0x1c0
[  142.849593]  [<ffffffff8100aedc>] call_softirq+0x1c/0x30
[  142.849599]  [<ffffffff8100ca65>] do_softirq+0x65/0xa0
[  142.849606]  [<ffffffff81063b75>] irq_exit+0x85/0x90
[  142.849614]  [<ffffffff813153aa>] xen_evtchn_do_upcall+0x12a/0x200
[  142.849622]  [<ffffffff8100af2e>] xen_do_hypervisor_callback+0x1e/0x30
[  142.849627]  <EOI>
[  142.849635]  [<ffffffff8110dec6>] ? copy_page_range+0x606/0x8e0
[  142.849642]  [<ffffffff81059b2e>] ? dup_mm+0x32e/0x610
[  142.849649]  [<ffffffff8105b070>] ? copy_process+0x11f0/0x1320
[  142.849659]  [<ffffffff8114b43b>] ? do_filp_open+0x18b/0x660
[  142.849666]  [<ffffffff8105b2e4>] ? do_fork+0xf4/0x410
[  142.849675]  [<ffffffff8155eac5>] ? _raw_spin_lock_irq+0x15/0x20
[  142.849683]  [<ffffffff8106fbbb>] ? recalc_sigpending+0x1b/0x50
[  142.849690]  [<ffffffff81070382>] ? sigprocmask+0x92/0x110
[  142.849698]  [<ffffffff81012bf8>] ? sys_clone+0x28/0x30
[  142.849706]  [<ffffffff8100a313>] ? stub_clone+0x13/0x20
[  142.849713]  [<ffffffff81009ff2>] ? system_call_fastpath+0x16/0x1b
...
[  142.849760] Call Trace:
[  142.849763]  <IRQ>  [<ffffffff81550263>] panic+0x7d/0xff
[  142.849774]  [<ffffffff8155e9ee>] ? _raw_spin_unlock_irqrestore+0x1e/0x30
[  142.849782]  [<ffffffff8155fd5a>] oops_end+0xea/0xf0
[  142.849788]  [<ffffffff8154fbc7>] no_context+0x209/0x218
[  142.849795]  [<ffffffff8154fd5b>] __bad_area_nosemaphore+0x185/0x1a8
[  142.849802]  [<ffffffff8154fd91>] bad_area_nosemaphore+0x13/0x15
[  142.849809]  [<ffffffff8156253a>] do_page_fault+0x2ca/0x390
[  142.849816]  [<ffffffff8155f075>] page_fault+0x25/0x30
[  142.849822]  [<ffffffff81465fee>] ? netif_receive_skb+0x1ee/0x640
[  142.849829]  [<ffffffff810316de>] ? pvclock_clocksource_read+0x4e/0x100
[  142.849836]  [<ffffffff813c7d4c>] xennet_poll+0x5ec/0xdd0
[  142.849843]  [<ffffffff81467152>] net_rx_action+0x122/0x240
[  142.849850]  [<ffffffff81063967>] __do_softirq+0xb7/0x1c0
[  142.849856]  [<ffffffff8100aedc>] call_softirq+0x1c/0x30
[  142.849862]  [<ffffffff8100ca65>] do_softirq+0x65/0xa0
[  142.849869]  [<ffffffff81063b75>] irq_exit+0x85/0x90
[  142.849875]  [<ffffffff813153aa>] xen_evtchn_do_upcall+0x12a/0x200
[  142.849882]  [<ffffffff8100af2e>] xen_do_hypervisor_callback+0x1e/0x30
[  142.849887]  <EOI>  [<ffffffff8110dec6>] ? copy_page_range+0x606/0x8e0
[  142.849898]  [<ffffffff81059b2e>] ? dup_mm+0x32e/0x610
[  142.849904]  [<ffffffff8105b070>] ? copy_process+0x11f0/0x1320
[  142.849911]  [<ffffffff8114b43b>] ? do_filp_open+0x18b/0x660
[  142.849918]  [<ffffffff8105b2e4>] ? do_fork+0xf4/0x410
[  142.849924]  [<ffffffff8155eac5>] ? _raw_spin_lock_irq+0x15/0x20
[  142.849930]  [<ffffffff8106fbbb>] ? recalc_sigpending+0x1b/0x50
[  142.849937]  [<ffffffff81070382>] ? sigprocmask+0x92/0x110
[  142.849943]  [<ffffffff81012bf8>] ? sys_clone+0x28/0x30
[  142.849950]  [<ffffffff8100a313>] ? stub_clone+0x13/0x20
[  142.849956]  [<ffffffff81009ff2>] ? system_call_fastpath+0x16/0x1b


[2] Click config:
define($PHY eth0, $TUN fake0);
define($PHYIP 135.254.219.12, $PHYMAC 00:16:3f:1f:7a:01);
define($TUNIP 11.4.1.1, $TUNMAC ae:72:26:91:bc:3f);

AddressInfo(this-public $PHYIP $PHYMAC);
AddressInfo(this $TUNIP/8 $TUNMAC);

fd :: FromDevice($PHY)
the :: ToHost($PHY)

fh :: FromHost($TUN, this:ipnet, ETHER this:eth, MTU 1350);

fd -> the;
fh -> Discard;