Re: [PATCH v8 1/4] fs/proc/kcore: avoid bounce buffer for ktext data

Baoquan He
2023-07-24T08:09:43Z

On 07/24/23 at 08:23am, David Hildenbrand wrote:
> Hi,
>
> >
> > I met this too when I executed below command to trigger a kcore reading.
> > I wanted to do a simple testing during system running and got this.
> >
> > makedumpfile --mem-usage /proc/kcore
> >
> > Later I tried your above objdump testing, it corrupted system too.
> >
>
> What do you mean with "corrupted system too" -- did it not only fail to
> dump the system, but also actually harmed the system?

From my testing, reading kcore will cause system panic, then reboot. Not
sure if Jiri saw the same phenomenon.

>
> @Lorenzo do you plan on reproduce + fix, or should we consider reverting
> that change?

When tested on a arm64 system, the reproducution is stable. I will have
a look too to see if I have some finding this week.