Re: 4.11rc3 unwinder spew.

From: Josh Poimboeuf
Date: Tue Mar 21 2017 - 14:21:08 EST


On Mon, Mar 20, 2017 at 06:13:25PM -0400, Dave Jones wrote:
> I just got this while running a backup..
>
> Dave
>
> WARNING: kernel stack frame pointer at ffffc90000fe7ff0 in rsync:1157 has bad value (null)
> unwind stack type:0 next_sp: (null) mask:2 graph_idx:0
> ffffc90000fe7f98: ffffc90000fe7ff0 (0xffffc90000fe7ff0)
> ffffc90000fe7fa0: ffffffffb7000f56 (trace_hardirqs_off_thunk+0x1a/0x1c)
> ffffc90000fe7fa8: 0000000000000246 (0x246)
> ffffc90000fe7fb0: 0000000000000000 ...
> ffffc90000fe7fc0: 00007ffe3af639bc (0x7ffe3af639bc)
> ffffc90000fe7fc8: 0000000000000006 (0x6)
> ffffc90000fe7fd0: 00007f80af433fc5 (0x7f80af433fc5)
> ffffc90000fe7fd8: 00007ffe3af638e0 (0x7ffe3af638e0)
> ffffc90000fe7fe0: 00007ffe3af638e0 (0x7ffe3af638e0)
> ffffc90000fe7fe8: 00007ffe3af63970 (0x7ffe3af63970)
> ffffc90000fe7ff0: 0000000000000000 ...
> ffffc90000fe7ff8: ffffffffb7b74b9a (entry_SYSCALL_64_after_swapgs+0x17/0x4f)

Thanks, this is a known issue with the unwinder getting confused about
interrupts hitting in early entry code. I'm working on a patch to fix
it.

--
Josh