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Subject: Re: [RFC v5 2/4] pstore/blk: add sample for pstore_blk
To:     Kees Cook <keescook@chromium.org>
Cc:     Anton Vorontsov <anton@enomsg.org>,
        Colin Cross <ccross@android.com>,
        Tony Luck <tony.luck@intel.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "David S. Miller" <davem@davemloft.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Arnd Bergmann <arnd@arndb.de>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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Date:   Sat, 19 Jan 2019 17:26:06 +0800
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On 2019-01-18 08:21, Kees Cook wrote:
> On Thu, Jan 17, 2019 at 4:15 PM Kees Cook <keescook@chromium.org> wrote:
>>
>> On Mon, Jan 7, 2019 at 4:01 AM liaoweixiong
>> <liaoweixiong@allwinnertech.com> wrote:
>>>
>>> It is a sample for pstore_blk, using general ram rather than block device.
>>> According to pstore_blk, the data will be saved to ram buffer if not
>>> register device path and apis for panic. So, it can only used to dump
>>> Oops and some things will not reboot.
>>
>> I'm not sure I see the purpose of this implementation? Doesn't this
>> just cause all the pstore machinery to skip any actions? i.e. without
>> bzinfo->part_path, won't blkz_sample_write() just return -EINVAL, etc?
> 
> Say, instead of a no-op driver, can you build something like the how
> ramoops processes module parameters, so that a person can define an
> arbitrary device at boot time for blkoops? This also allows for easier
> runtime testing too.

Sure, i will do it in next version. But it can only use for oops,
excluding panic.
I have no idea how to pass panic operation parameters.

> 
> This all looks good, with some minor tweaks as mentioned. And on
> closer review, yeah, it doesn't look like it shares much with ramoops.
> :)
> 
> Thanks for sending this series; I look forward to the next version. :)
> 
> -Kees
>