Re: Crash in msm serial on dragonboard with ftrace bootargs

From: Kees Cook
Date: Tue Oct 16 2018 - 13:03:03 EST


On Tue, Oct 16, 2018 at 8:29 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Tue, 16 Oct 2018 17:08:25 +0530
> Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx> wrote:
>> One more thing is for pstore dmesg-ramoops, I had to change
>> late_initcall to postcore_initcall which brings the question as to why
>> we changed to late_initcall?
>> Simple git blame shows to support crypto compress api, but is it really
>> helpful? A lot of boottime issues can be caught with pstore enabled at
>> postcore_initcall rather than late_initcall, this backtrace
>> is just one example. Is there any way we could change this?
>
> Does it break if the crypto is not initialized? Perhaps add a command
> line flag to have it happen earlier:
>
> ramoops=earlyinit
>
> and add a postcore_initcall that checks if that flag is set, and if so,
> it does the work then, and the late_initcall() will do nothing.
>
> That way, you can still have unmodified kernels use pstore when it
> crashes at boot up.

Even better, if we could find a way to make it work with a late
initialization of compression (i.e. postcore_initcall() by default
means anything caught would be uncompressed, but anything after
late_initcall() would be compressed). I'd be very happy to review
patches for that!

-Kees

--
Kees Cook
Pixel Security