RTnet splash with current next and stable

Pintu Agarwal pintu.ping at gmail.com
Thu Dec 13 10:55:58 CET 2018


On Tue, Dec 4, 2018 at 10:30 PM Jan Kiszka via Xenomai
<xenomai at xenomai.org> wrote:
>
> On 31.10.18 18:10, Philippe Gerum wrote:
> > On 10/30/18 11:28 AM, Jan Kiszka wrote:
> >> Hi all,
> >>
> >> just testing new kernels with smokey, and one of them had RTnet on. This
> >> triggered a bug with the net_packat_dgram test:
> >>
> >> [   50.610997] initializing loopback...
> >> [   50.613799] RTnet: registered rtlo
> >> [   50.692154] ------------[ cut here ]------------
> >> [   50.693577] WARNING: CPU: 1 PID: 1119 at ../lib/list_debug.c:29 __list_add+0x62/0xb0
> >> [   50.696832] list_add corruption. next->prev should be prev (ffffffffa0007d20), but was           (null). (next=ffff88003a8bb700).
> >> [   50.700751] Modules linked in: rtpacket rtipv4 rt_loopback rt_e1000e rtnet
> >> [   50.702518] CPU: 1 PID: 1119 Comm: smokey Not tainted 4.9.135+ #26
> >> [   50.704188] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
> >> [   50.707861] I-pipe domain: Linux
> >> [   50.709295]  ffffc90002943c10 ffffffff8146a31a ffffc90002943c60 0000000000000000
> >> [   50.710335]  ffffc90002943c50 ffffffff810e9441 0000001da0007ca8 ffff88003a8bb700
> >> [   50.710335]  ffffffffa0007d20 ffff88003a8bb700 000000000001d230 ffff88003a8bb640
> >> [   50.710335] Call Trace:
> >> [   50.710335]  [<ffffffff8146a31a>] dump_stack+0xa2/0xc8
> >> [   50.710335]  [<ffffffff810e9441>] __warn+0xe1/0x100
> >> [   50.710335]  [<ffffffff810e94af>] warn_slowpath_fmt+0x4f/0x60
> >> [   50.710335]  [<ffffffff812b0b61>] ? __slab_alloc.isra.88+0xa1/0xd0
> >> [   50.710335]  [<ffffffffa0003edb>] ? rtskb_pool_extend+0xbb/0x220 [rtnet]
> >> [   50.710335]  [<ffffffff81498862>] __list_add+0x62/0xb0
> >> [   50.710335]  [<ffffffffa000160a>] rtdev_map_rtskb+0x7a/0xa0 [rtnet]
> >> [   50.710335]  [<ffffffffa0003f12>] rtskb_pool_extend+0xf2/0x220 [rtnet]
> >> [   50.710335]  [<ffffffffa0004072>] rtskb_pool_init+0x32/0x70 [rtnet]
> >> [   50.710335]  [<ffffffffa00043d2>] __rt_bare_socket_init+0x42/0x90 [rtnet]
> >> [   50.710335]  [<ffffffffa0004501>] __rt_socket_init+0x81/0xd0 [rtnet]
> >> [   50.710335]  [<ffffffffa0054477>] rt_packet_socket+0x27/0xb0 [rtpacket]
> >> [   50.710335]  [<ffffffff81219dd7>] ? create_instance+0x67/0x80
> >> [   50.710335]  [<ffffffff8121a772>] __rtdm_dev_socket+0x112/0x440
> >> [   50.710335]  [<ffffffff8113bb09>] ? lock_release+0x2c9/0x440
> >> [   50.710335]  [<ffffffff8122b200>] ? CoBaLt_open+0x40/0x40
> >> [   50.710335]  [<ffffffff8122b20e>] CoBaLt_socket+0xe/0x20
> >> [   50.710335]  [<ffffffff812412ca>] ipipe_syscall_hook+0x19a/0x460
> >> [   50.710335]  [<ffffffff811ad8e9>] __ipipe_notify_syscall+0x79/0x400
> >> [   50.710335]  [<ffffffff811adc9a>] ipipe_handle_syscall+0x2a/0xd0
> >> [   50.710335]  [<ffffffff81002d6c>] do_syscall_64+0x3c/0x1c0
> >> [   50.710335]  [<ffffffff8184f2c3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
> >> [   50.761499] ---[ end trace 633f1ec8aecb0735 ]---
> >> [   50.762893] ------------[ cut here ]------------
> >>
> >> Anyone who hacked on this recently have a feeling?
> >>
> >
> > No idea. I'll have a look.
> >
> >
>
> I think this one is still open. At least I do not remember having merged
> anything related to that since then.
>
> As everyone is busy right now, I only wonder if we have a regression here, or if
> it's just a preexisting issue that we can safely ignore for some v3.0.8.
>
> Jan
>

I think I already reported similar rtnet loopback issue around 6
months ago with 3.0.6 itself.
This kind of issues are visible on x86, Beagle Bone/Raspberry Pi
(arm), Hikey (arm64) , even with SMAP disabled in Kernel 4.9.x
However, I did not see this issue with Virtual Box (Ubuntu guest).

> --
> Siemens AG, Corporate Technology, CT RDA IOT SES-DE
> Corporate Competence Center Embedded Linux
>



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