Re: WARNING: can't access registers at asm_common_interrupt

[Josh Poimboeuf]

On Fri, Nov 06, 2020 at 06:04:15AM +0000, Shinichiro Kawasaki wrote:
> Greetings,
> 
> I observe "WARNING: can't access registers at asm_common_interrupt+0x1e/0x40"
> in my kernel test system repeatedly, which is printed by unwind_next_frame() in
> "arch/x86/kernel/unwind_orc.c". Syzbot already reported that [1]. Similar
> warning was reported and discussed [2], but I suppose the cause is not yet
> clarified.
> 
> The warning was observed with v5.10-rc2 and older tags. I bisected and found
> that the commit 044d0d6de9f5 ("lockdep: Only trace IRQ edges") in v5.9-rc3
> triggered the warning. Reverting that from 5.10-rc2, the warning disappeared.
> May I ask comment by expertise on CC how this commit can relate to the warning?
> 
> The test condition to reproduce the warning is rather unique (blktests,
> dm-linear and ZNS device emulation by QEMU). If any action is suggested for
> further analysis, I'm willing to take it with my test system.

Hi,

Thanks for reporting this issue.  This might be a different issue from
[2].

Can you send me the arch/x86/entry/entry_64.o file from your build?

-- 
Josh