Re: BUG: soft lockup in 4.10-rc7 with KASAN enabled

[Andrey Ryabinin]

On 02/09/2017 03:46 PM, Tobias Regnery wrote:
> Hi,
> 
> I hit a soft lockup with 4.10-rc7 on ervery boot:
>

...

> [   32.452189] NMI watchdog: BUG: soft lockup - CPU#3 stuck for 23s! [swapper/0:1]
> [   32.452300] Modules linked in:
> [   32.452388] CPU: 3 PID: 1 Comm: swapper/0 Tainted: G             L  4.10.0-rc7-kasan #27
> [   32.452504] Hardware name: LENOVO Lenovo IdeaPad N581/INVALID, BIOS 5ECN96WW(V9.01) 03/14/2013
> [   32.452621] task: ffff88010a268000 task.stack: ffff88010a270000
> [   32.452711] RIP: 0010:note_page+0x781/0xa60
> [   32.452792] RSP: 0018:ffff88010a277d30 EFLAGS: 00000287 ORIG_RAX: ffffffffffffff10
> [   32.452911] RAX: fffffbfff228dde7 RBX: ffff88010a277e40 RCX: ffffffff900a3947
> [   32.453000] RDX: dffffc0000000000 RSI: ffff88010a277e40 RDI: ffffffff9146ef38
> [   32.453087] RBP: ffff88010a277da0 R08: 1ffffffff2290598 R09: ffffffff91b1a952
> [   32.453173] R10: ffff8800bf3fffff R11: fffffbfff236352b R12: 8000000000000161
> [   32.453261] R13: 0000000000000000 R14: ffffffff9146ef20 R15: fffff698470e8000
> [   32.453350] FS:  0000000000000000(0000) GS:ffff88010b2c0000(0000) knlGS:0000000000000000
> [   32.453467] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   32.453551] CR2: ffffffff90e40ea0 CR3: 00000000bf40d000 CR4: 00000000001406e0
> [   32.453636] Call Trace:
> [   32.453718]  ptdump_walk_pgd_level_core+0x40c/0x550
> [   32.453804]  ? note_page+0xa60/0xa60
> [   32.453890]  ? free_reserved_area+0x131/0x140
> [   32.453975]  ? 0xffffffff90000000
> [   32.454058]  ptdump_walk_pgd_level_checkwx+0x17/0x20
> [   32.454147]  mark_rodata_ro+0x13b/0x150
> [   32.454234]  ? rest_init+0x90/0x90
> [   32.454318]  kernel_init+0x2f/0x120
> [   32.454400]  ? rest_init+0x90/0x90
> [   32.454482]  ret_from_fork+0x2c/0x40

Yeah, that's ptdump walks too long across huge KASAN shadow memory without rescheduling.
Patch to fix this will follow shortly.