Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 10 Aug 2023 20:05:40 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Vijay Balakrishna <vijayb@linux.microsoft.com>
Cc:     Petr Mladek <pmladek@suse.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        John Ogness <john.ogness@linutronix.de>,
        Colin Cross <ccross@android.com>,
        Tony Luck <tony.luck@intel.com>,
        Anton Vorontsov <anton@enomsg.org>,
        linux-kernel@vger.kernel.org
Subject: Re: pstore/ram: printk: NULL characters in pstore ramoops area
Message-ID: <202308102001.55158F519@keescook>
References: <f28990eb-03bc-2259-54d0-9f2254abfe62@linux.microsoft.com>
 <202308040053.7F38C6D@keescook>
 <0220f601-14f8-1dda-f057-73a608fbe62b@linux.microsoft.com>
 <202308101649.337F4D8@keescook>
 <0dace822-ce13-906e-46bd-e1cb9274cafe@linux.microsoft.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <0dace822-ce13-906e-46bd-e1cb9274cafe@linux.microsoft.com>
Precedence: bulk

On Thu, Aug 10, 2023 at 05:48:17PM -0700, Vijay Balakrishna wrote:
> On 8/10/23 16:50, Kees Cook wrote:
> > Can you share the .config you're building with? And what are you using
> > to trigger an Oops? I will see if I can reproduce this...
> 
> Config: https://paste.ubuntu.com/p/Vrcsf8Ry9g/

Thanks! I'll see how close I can get to this for my local testing...

> 
> Just ran plain "sudo reboot" and inspected /var/lib/systemd/pstore/dmesg-ramoops-0 after reboot.

If you have a "dmesg-ramoops-0" there, something Oopsed. On a clean
shutdown, only "console-ramoops-0" will be recorded. Can you double
check by deleting everything in /var/lib/systemd/pstore/ and rebooting?

If you still get a dmesg-ramoops-0 file, can you upload that somewhere
so I can look at it?

Also, can you send the contents of /proc/iomem ?

-- 
Kees Cook