Re: [PATCH v6 1/7] kexec_file: allow to place kexec_buf randomly

[Coiby Xu]

On Fri, Nov 29, 2024 at 09:38:58AM +0800, Baoquan He wrote:
> On 10/29/24 at 01:52pm, Coiby Xu wrote:
> > Currently, kexec_buf is placed in order which means for the same
> > machine, the info in the kexec_buf is always located at the same
> > position each time the machine is booted. This may cause a risk for
> > sensitive information like LUKS volume key. Now struct kexec_buf has a
> > new field random which indicates it's supposed to be placed in a random
> > position.
>
> This change the generic code, but you don't mention this only takes
> effect in kdump case, won't impact kexec reboot case. I got this from
> code, while this should be mentioned in log.

Thanks for the reminder! I'll put a note in the commit msg.

>
[...]
> > +
> > +#ifdef CONFIG_CRASH_DUMP
> > +static inline void kexec_random_start(unsigned long start, unsigned long end,
>                      ~~~~~~~~~~~~~~~~~~
> This function name is very confusing. I thought it's a starting to
> randomize at the first glance, then realized it's to randomize the
> starting position of range.

Thanks for raising this concern! I'll rename it to
kexec_random_range_start.

--
Best regards,
Coiby