Re: [BUG REPORT] firmware: arm_scmi: Shared Memory Overwritten in SCMI Mailbox Communication

From: Cristian Marussi <cristian.marussi@arm.com>
To: Shivnandan Kumar <quic_kshivnan@quicinc.com>
Cc: xinglong.yang@cixtech.com, linux-arm-kernel@lists.infradead.org,
	sudeep.holla@arm.com
Subject: Re: [BUG REPORT] firmware: arm_scmi: Shared Memory Overwritten in SCMI Mailbox Communication
Date: Fri, 8 Mar 2024 08:33:17 +0000	[thread overview]
Message-ID: <ZerNTSeSfgLXiPb7@pluto> (raw)
In-Reply-To: <c17b246c-182b-432c-a6eb-e3f276c21a60@quicinc.com>

On Fri, Mar 08, 2024 at 11:46:07AM +0530, Shivnandan Kumar wrote:
> On 12/13/2023 11:32 AM, Xinglong Yang wrote:
> > The shared memory is overwritten happened in some condition and the detail are
> > as follows:
> > Based on mailbox transportation. The thread A is waiting for response and The
> > thread B is waiting the mark_txdone() to submit the next message. When the thread
> > A is timed out because that the callee do not reply promptly and then caller begins
> > to tx_tick() for the next message(for thread B). At the same time, the shared memory
> > is written by the callee(response for thread A) and set channel free. After the callee
> > has written the shared memory. The caller written the shared memory again for
> > thread B. In such case the shared memory written by callee is overwritten by caller.
> > Later, the caller received the completion IRQ for Thread A(BUT has been overwritten
> > by Thread B's tx->buffer). The caller checks the shared memory discover that the buffer
> > is error. Which case triggers a chain of errors.
> > 
> > The part of error logs are as follows:
> > [    19.135368] arm-scmi firmware:scmi: timed out in resp(caller: xxx)
> > [    19.508536] arm-scmi firmware:scmi: Invalid message type:0 for 301 - HDR:0x%X state:1
> > 
> > Because the same token ID are received twice by caller, the second IRQ with the same token
> > will be treated as invalid message and abandoned.
> > 
> > Regards,
> > Xinglong
> > 
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
> 
> hi Xinglong,
> 

Hi Shivnandan,

> I encountered the same issue recently.
> Is any fix identified/merged for this in a separate thread?

This fix has beem merged back to 5.15 stable.

https://lore.kernel.org/linux-arm-kernel/20231220172112.763539-1-cristian.marussi@arm.com/

Thanks,
Cristian

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