Re: [PATCH 0/2] printk: replace ringbuffer

From: John Ogness
Date: Wed Feb 05 2020 - 04:00:23 EST


On 2020-02-05, Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx> wrote:
>>>> So there is a General protection fault. That's the type of a
>>>> problem that kills the boot for me as well (different backtrace,
>>>> tho).
>>>
>>> Do you have CONFIG_RELOCATABLE and CONFIG_RANDOMIZE_BASE (KASLR)
>>> enabled?
>>
>> Yes. These two options are enabled.
>>
>> CONFIG_RELOCATABLE=y
>> CONFIG_RANDOMIZE_BASE=y
>
> So KASLR kills the boot for me. So does KASAN.

Sergey, thanks for looking into this already!

> John, do you see any of these problems on your test machine?

For x86 I have only been using qemu. (For hardware tests I use arm64-smp
in order to verify memory barriers.) With qemu-x86_64 I am unable to
reproduce the problem.

Lianbo, thanks for the report. Can you share your boot args? Anything
special in there (like log_buf_len=, earlyprintk, etc)?

Also, could you share your CONFIG_LOG_* and CONFIG_PRINTK_* options?

I will move to bare metal x86_64 and hopefully see it as well.

John