Re: [Crash-utility] About referring to struct load_module from extension modules
Hagio-san,
Sorry for the delayed response.
________________________________________
From: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com>
Sent: Thursday, September 28, 2023 9:03
To: Hatayama, Daisuke/畑山 大輔
Cc: crash-utility(a)redhat.com
Subject: Re: About referring to struct load_module from extension modules
On 2023/09/26 19:21, Daisuke Hatayama (Fujitsu) wrote:
...snip...
> On the other hand, is it OK to refer to struct load_module
directly
> from extension modules?
Yes, I think it's ok.
>
> I'm not the original author of crash trace command. I've just found
> crash trace doing like this for the first time.
>
> - If it is OK to refer to struct load_module directly from extension
> modules, should it be backward compatible on it? Or extension
> modules should absorb the incompatibility?
The crash-utility considers extension modules somewhat (e.g. [1]), but
AFAIK there is no other strict rule about the compatibility. We cannot
know what is used by extension modules. If crash has to keep their
backward-compatibility, all global variables and functions have to be
compatible. That will make crash development inefficient or maybe
sometimes impossible depending on a kernel change. So I think that
crash changes should be handled by extension modules, same as kernel
changes.
[1] https://github.com/crash-utility/crash/wiki#writing-patches
Thanks,
Kazu
Thank you for your suggestion.
I agree to you because:
- The bad effect for development and maintenance of crash utility is
not preferable also for extension modules.
- Module layout changes that affect crash utility thus far appears
rare according to the source code; the module layout change is v3.
- It is easy for crash trace to deal with the module layout change
this time.
On the other hand, there could be the change in crash utility where
it's difficult for extension modules to deal with in the future. In
that case, I'll discuss them as necessary.
Thanks.
HATAYAMA, Daisuke