Re: printk feature for syzbot?

[Sergey Senozhatsky]

On (04/26/18 12:06), Petr Mladek wrote:
> 
> > Petr, Steven, Fengguang, what do you think? Do you have any objections?
> > Ideas?
> 
> I wonder if we could create some mechanism that would help to extend
> struct printk_log easier in the future.

Hm, interesting idea.

> I know only about crash tool implementation. It uses information provided
> by log_buf_vmcoreinfo_setup(). The size of the structure is already
> public. Therefore crash should be able to find all existing information
> even if we increase the size of the structure.
> 
> log_buf_vmcoreinfo_setup() even allows to inform about newly added
> structure items. We could probably extend it to inform also about
> the offset of the new optional elements.

I vaguely remember that the last time Thomas Gleixner modified
printk_log you managed to find a case that broke crash tool.
... Or may be I'm mistaken.

> I am not sure about other tools. But I think that it should be
> doable.

Good. So there are no objections, so far.

Tetsuo, Dmitry, care to send a patch?

	-ss