Re: Linux 5.0 regression: rtl8169 / kernel BUG at lib/dynamic_queue_limits.c:27!

[Heiner Kallweit]

On 08.02.2019 19:29, Sander Eikelenboom wrote:
> L.S.,
> 
> While testing a linux 5.0-rc5 kernel (with some patches on top but they don't seem related) under Xen i the nasty splat below, 
> that I haven encountered with Linux 4.20.x.
> 
> Unfortunately I haven't got a clear reproducer for this and bisecting could be nasty due to another (networking related) kernel bug.
> 
> If you need more info, want me to run a debug patch etc., please feel free to ask.
> 
Thanks for the report. However I see no change in the r8169 driver between
4.20 and 5.0 with regard to BQL code. Having said that the root cause could
be somewhere else. Therefore I'm afraid a bisect will be needed.

> --
> Sander
> 
Heiner

> 
> [ 6466.554866] kernel BUG at lib/dynamic_queue_limits.c:27!
> [ 6466.571425] invalid opcode: 0000 [#1] SMP NOPTI
> [ 6466.585890] CPU: 3 PID: 7057 Comm: as Not tainted 5.0.0-rc5-20190208-thp-net-florian-doflr+ #1
> [ 6466.598693] Hardware name: MSI MS-7640/890FXA-GD70 (MS-7640)  , BIOS V1.8B1 09/13/2010
> [ 6466.611579] RIP: e030:dql_completed+0x126/0x140
> [ 6466.624339] Code: 2b 47 54 ba 00 00 00 00 c7 47 54 ff ff ff ff 0f 48 c2 48 8b 15 7b 39 4a 01 48 89 57 58 e9 48 ff ff ff 44 89 c0 e9 40 ff ff ff <0f> 0b 8b 47 50 29 e8 41 0f 48 c3 eb 9f 90 90 90 90 90 90 90 90 90
> [ 6466.648130] RSP: e02b:ffff88807d4c3e78 EFLAGS: 00010297
> [ 6466.659616] RAX: 0000000000000042 RBX: ffff8880049cf800 RCX: 0000000000000000
> [ 6466.672835] RDX: 0000000000000001 RSI: 0000000000000042 RDI: ffff8880049cf8c0
> [ 6466.684521] RBP: ffff888077df7260 R08: 0000000000000001 R09: 0000000000000000
> [ 6466.696824] R10: 00000000387c2336 R11: 00000000387c2336 R12: 0000000010000000
> [ 6466.709953] R13: ffff888077df6898 R14: ffff888077df75c0 R15: 0000000000454677
> [ 6466.722165] FS:  00007fd869147200(0000) GS:ffff88807d4c0000(0000) knlGS:0000000000000000
> [ 6466.733228] CS:  e030 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 6466.746581] CR2: 00007fd867dfd000 CR3: 0000000074884000 CR4: 0000000000000660
> [ 6466.758366] Call Trace:
> [ 6466.768118]  <IRQ>
> [ 6466.778214]  rtl8169_poll+0x4f4/0x640
> [ 6466.789198]  net_rx_action+0x23d/0x370
> [ 6466.798467]  __do_softirq+0xed/0x229
> [ 6466.807039]  irq_exit+0xb7/0xc0
> [ 6466.815471]  xen_evtchn_do_upcall+0x27/0x40
> [ 6466.826647]  xen_do_hypervisor_callback+0x29/0x40
> [ 6466.835902]  </IRQ>
> [ 6466.845361] RIP: e030:xen_hypercall_mmu_update+0xa/0x20
> [ 6466.853390] Code: 51 41 53 b8 00 00 00 00 0f 05 41 5b 59 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 51 41 53 b8 01 00 00 00 0f 05 <41> 5b 59 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
> [ 6466.874031] RSP: e02b:ffffc90003c0bdd0 EFLAGS: 00000246
> [ 6466.883452] RAX: 0000000000000000 RBX: 000000041f83bfe8 RCX: ffffffff8100102a
> [ 6466.891986] RDX: deadbeefdeadf00d RSI: deadbeefdeadf00d RDI: deadbeefdeadf00d
> [ 6466.903402] RBP: 0000000000000fe8 R08: 000000000000000b R09: 0000000000000000
> [ 6466.911201] R10: deadbeefdeadf00d R11: 0000000000000246 R12: 800000050c346067
> [ 6466.918491] R13: ffff8880607c4fe8 R14: ffff888005082800 R15: 0000000000000000
> [ 6466.926647]  ? xen_hypercall_mmu_update+0xa/0x20
> [ 6466.938195]  ? xen_set_pte_at+0x78/0xe0
> [ 6466.947046]  ? __handle_mm_fault+0xc43/0x1060
> [ 6466.955772]  ? do_mmap+0x44b/0x5b0
> [ 6466.964410]  ? handle_mm_fault+0xf8/0x200
> [ 6466.973290]  ? __do_page_fault+0x231/0x4a0
> [ 6466.981973]  ? page_fault+0x8/0x30
> [ 6466.990904]  ? page_fault+0x1e/0x30
> [ 6466.999585] Modules linked in:
> [ 6467.007533] ---[ end trace 94bec01608fe4061 ]---
> [ 6467.016751] RIP: e030:dql_completed+0x126/0x140
> [ 6467.024271] Code: 2b 47 54 ba 00 00 00 00 c7 47 54 ff ff ff ff 0f 48 c2 48 8b 15 7b 39 4a 01 48 89 57 58 e9 48 ff ff ff 44 89 c0 e9 40 ff ff ff <0f> 0b 8b 47 50 29 e8 41 0f 48 c3 eb 9f 90 90 90 90 90 90 90 90 90
> [ 6467.039726] RSP: e02b:ffff88807d4c3e78 EFLAGS: 00010297
> [ 6467.047243] RAX: 0000000000000042 RBX: ffff8880049cf800 RCX: 0000000000000000
> [ 6467.054202] RDX: 0000000000000001 RSI: 0000000000000042 RDI: ffff8880049cf8c0
> [ 6467.062000] RBP: ffff888077df7260 R08: 0000000000000001 R09: 0000000000000000
> [ 6467.069664] R10: 00000000387c2336 R11: 00000000387c2336 R12: 0000000010000000
> [ 6467.077715] R13: ffff888077df6898 R14: ffff888077df75c0 R15: 0000000000454677
> [ 6467.084916] FS:  00007fd869147200(0000) GS:ffff88807d4c0000(0000) knlGS:0000000000000000
> [ 6467.093352] CS:  e030 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 6467.101492] CR2: 00007fd867dfd000 CR3: 0000000074884000 CR4: 0000000000000660
> [ 6467.110542] Kernel panic - not syncing: Fatal exception in interrupt
> [ 6467.118166] Kernel Offset: disabled
> (XEN) [2019-02-08 18:04:48.854] Hardware Dom0 crashed: rebooting machine in 5 seconds.
>