Re: AMD-IOMMU and problem with __init(data)?

[Alexander Holler <holler@ahsoftware.de>]

Am 23.09.2015 um 13:43 schrieb Joerg Roedel:
> Hey Alexander,
>
> On Wed, Sep 23, 2015 at 12:22:24PM +0200, Alexander Holler wrote:
>> [    1.539496] AMD-Vi: Lazy IO/TLB flushing enabled
>> [    1.545741] AHO: count_annotated 25
>> [    1.549259] AHO: build inventory
>> [    1.552517] AHO: ac ffffffff81d400d8 ic           (null) ID
>> 2177560225 deps 00000000000000b0 drv ffffffff81d25090
>> [    1.562801] BUG: unable to handle kernel paging request at
>> 00000000039c2af5
>> (...)
>
> Do you possibly have the full BUG message including the stacktrace?

The full msg is

---------
[    1.552517] AHO: ac ffffffff81d400d8 ic           (null) ID 
2177560225 deps 00000000000000b0 drv ffffffff81d25090
[    1.562801] BUG: unable to handle kernel paging request at 
00000000039c2af5
[    1.569889] IP: [<ffffffff81c9d7b4>] do_annotated_initcalls+0x6f/0x25b
[    1.576490] PGD 0
[    1.578587] Oops: 0002 [#1] SMP
[    1.581947] Modules linked in:
[    1.585085] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 
4.2.1-deps-00154-gb5f382c-dirty #768
[    1.593374] Hardware name: System manufacturer System Product 
Name/F2A85-M, BIOS 6508 07/11/2014
[    1.602184] task: ffff88042d508000 ti: ffff88042d510000 task.ti: 
ffff88042d510000
[    1.609693] RIP: 0010:[<ffffffff81c9d7b4>]  [<ffffffff81c9d7b4>] 
do_annotated_initcalls+0x6f/0x25b
[    1.618718] RSP: 0018:ffff88042d513f08  EFLAGS: 00010296
[    1.624056] RAX: 0000000081caeea1 RBX: ffffffff81d400d8 RCX: 
0000000000000000
[    1.631210] RDX: 0000000081caeea1 RSI: 0000000000000246 RDI: 
ffffffff81da7ae8
[    1.638365] RBP: 0000000000000001 R08: 0000000000000000 R09: 
0000000000000000
[    1.645519] R10: 00000000000001f9 R11: 0000000000000006 R12: 
0000000000000000
[    1.652676] R13: 0000000000000000 R14: 0000000000000000 R15: 
0000000000000000
[    1.659830] FS:  0000000000000000(0000) GS:ffff88043ec00000(0000) 
knlGS:0000000000000000
[    1.667940] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    1.673707] CR2: 00000000039c2af5 CR3: 0000000001c0b000 CR4: 
00000000000406f0
[    1.680864] Stack:
[    1.682908]  0000000000000006 0000000000000001 0000000000000000 
ffffffff81c9ced8
[    1.690531]  0000000080000000 ffffffff8164b3d0 0000000000000000 
ffffffff8164b3d9
[    1.698153]  ffffffff81c25380 ffffffff81656f5f 0000000000000000 
0000000000000000
[    1.705777] Call Trace:
[    1.708255]  [<ffffffff81c9ced8>] ? kernel_init_freeable+0xda/0x16a
[    1.714544]  [<ffffffff8164b3d0>] ? rest_init+0x70/0x70
[    1.719793]  [<ffffffff8164b3d9>] ? kernel_init+0x9/0xe0
[    1.725129]  [<ffffffff81656f5f>] ? ret_from_fork+0x3f/0x70
[    1.730724]  [<ffffffff8164b3d0>] ? rest_init+0x70/0x70
[    1.735974] Code: d4 81 73 4d 8b 4b 08 85 c9 74 40 48 8b 13 4c 8b 4b 
18 48 89 de 4c 8b 43 10 48 c7 c7 e0 4e 9d 81 e8 1c fe 9a ff 8b 53 08 48 
89 d0 <c6> 82 54 3c d1 81 01 48 89 1c d5 40 f2 d0 81 8b 15 c7 63 07 00
[    1.758158] RIP  [<ffffffff81c9d7b4>] do_annotated_initcalls+0x6f/0x25b
[    1.764845]  RSP <ffff88042d513f08>
[    1.768361] CR2: 00000000039c2af5
[    1.771710] ---[ end trace 5a4348fb7eabd051 ]---
[    1.776363] ------------[ cut here ]------------
[    1.781010] WARNING: CPU: 0 PID: 1 at kernel/smp.c:292 
smp_call_function_single+0xe7/0x100()
[    1.789472] Modules linked in:
[    1.792610] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G      D 
4.2.1-deps-00154-gb5f382c-dirty #768
[    1.802112] Hardware name: System manufacturer System Product 
Name/F2A85-M, BIOS 6508 07/11/2014
[    1.810921]  0000000000000000 ffffffff819d6fba ffffffff8164f11e 
0000000000000000
[    1.818542]  ffffffff81039647 0000000000000000 ffffffff810c87c0 
ffffffff81c22040
[    1.826166]  0000000000000000 00000000039c2af5 ffffffff8109bc97 
ffff88042d513cf8
[    1.833790] Call Trace:
[    1.836267]  [<ffffffff8164f11e>] ? dump_stack+0x40/0x50
[    1.841603]  [<ffffffff81039647>] ? warn_slowpath_common+0x87/0xd0
[    1.847806]  [<ffffffff810c87c0>] ? cpu_clock_event_start+0x30/0x30
[    1.854095]  [<ffffffff8109bc97>] ? smp_call_function_single+0xe7/0x100
[    1.860729]  [<ffffffff810c7962>] ? task_function_call+0x42/0x50
[    1.866760]  [<ffffffff810cc670>] ? perf_cgroup_switch+0x160/0x160
[    1.872963]  [<ffffffff810ac800>] ? cgroup_exit+0xb0/0x130
[    1.878470]  [<ffffffff8103b987>] ? do_exit+0x347/0x9a0
[    1.883720]  [<ffffffff8100693c>] ? oops_end+0x8c/0xd0
[    1.888882]  [<ffffffff8102cd83>] ? no_context+0x123/0x370
[    1.894392]  [<ffffffff81658132>] ? page_fault+0x22/0x30
[    1.899728]  [<ffffffff81c9d7b4>] ? do_annotated_initcalls+0x6f/0x25b
[    1.906190]  [<ffffffff81c9d7ae>] ? do_annotated_initcalls+0x69/0x25b
[    1.912653]  [<ffffffff81c9ced8>] ? kernel_init_freeable+0xda/0x16a
[    1.918941]  [<ffffffff8164b3d0>] ? rest_init+0x70/0x70
[    1.924190]  [<ffffffff8164b3d9>] ? kernel_init+0x9/0xe0
[    1.929526]  [<ffffffff81656f5f>] ? ret_from_fork+0x3f/0x70
[    1.935123]  [<ffffffff8164b3d0>] ? rest_init+0x70/0x70
[    1.940371] ---[ end trace 5a4348fb7eabd052 ]---
[    1.945023] Kernel panic - not syncing: Attempted to kill init! 
exitcode=0x00000009
[    1.945023]
[    1.954235] ---[ end Kernel panic - not syncing: Attempted to kill 
init! exitcode=0x00000009
---------

The bug happens because the code tried to uses foo[ID] and with an ID of 
2177560225 it wents clearly out of bounds. ;)

>
>> If it's necessary, I could try put together a small patch which
>> kills a system (reproducible here).
>
> That would help too, please also send me your .config and I'll try to
> reproduce the issue here.

Will do. Later.

Thanks,

Regards,

Alexander Holler