Re: Race with ip=dhcp bootparameter in ip_rcv_finish on am335x

Hi,

On Wed, Sep 23, 2015 at 12:36:13PM +0200, Nikolay Aleksandrov wrote:

On 09/23/2015 12:29 PM, Alexander Aring wrote:

quoted

Hi,

I am using am335x (beaglebone white) with "ip=dhcp" inside my
bootparameters. It seems there exists some race, rarely it boots fine
and often it crashed with following messages:

First (Without successful dhcp ip assign and is very rarely):

[    6.249083] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[    6.398943] .
[    7.400822] Unable to handle kernel paging request at virtual address 7402a8c8
[    7.408419] pgd = c0004000
[    7.411351] [7402a8c8] *pgd=00000000
[    7.415121] Internal error: Oops: 5 [#1] SMP ARM
[    7.419968] Modules linked in:
[    7.423197] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W       4.2.0-11195-ge81be90 #124
[    7.432118] Hardware name: Generic AM33XX (Flattened Device Tree)
[    7.438509] task: c0a996c8 ti: c0a92000 task.ti: c0a92000
[    7.444189] PC is at ip_route_input_noref+0x620/0xeb4
[    7.449491] LR is at trace_hardirqs_on_caller+0xb0/0x1e8

<<<snip>>>

quoted

[    7.759169] [<c054b49c>] (ip_route_input_noref) from [<c0550668>] (ip_rcv_finish+0xd4/0x67c)

<<<snip>>>

quoted

--------

I tried to bisect this issue without success, sometimes it's booting fine
and sometimes I got the above messages. Could anybody help me here to
fixing this issue?

- Alex

Hi Alex,
This should be fixed by commit bde6f9ded1bd 
("net: Initialize table in fib result") in net-next.

I tried to cherry-picked this commit and saw this is already in net-next.
I also tried to boot current net, the race is still there.

- Alex