From: Hemant Kumar <quic_hemantk@quicinc.com>
To: Maxim Kochetkov <fido_max@inbox.ru>, <mhi@lists.linux.dev>
Cc: <manivannan.sadhasivam@linaro.org>, <bbhatt@codeaurora.org>,
"Maxim Kochetkov" <mkochetkov@airspan.com>
Subject: Re: [PATCH] net: qrtr: start MHI channel after endpoit creation
Date: Mon, 2 May 2022 19:35:05 -0700 [thread overview]
Message-ID: <642cccfd-6e70-9024-1a05-6df48a740156@quicinc.com> (raw)
In-Reply-To: <20220430103430.37349-1-fido_max@inbox.ru>
On 4/30/2022 3:34 AM, Maxim Kochetkov wrote:
> From: Maxim Kochetkov <mkochetkov@airspan.com>
>
> MHI channel may generates event/interrupt right after enabling.
> It may leads to 2 race conditions issues.
>
> 1)
> Such event may be dropped by qcom_mhi_qrtr_dl_callback() at check:
>
> if (!qdev || mhi_res->transaction_status)
> return;
>
> Because dev_set_drvdata(&mhi_dev->dev, qdev) may be not performed at
> this moment. In this situation qrtr-ns will be unable to enumerate
> services in device.
> ---------------------------------------------------------------
>
> 2)
> Such event may come at the moment after dev_set_drvdata() and
> before qrtr_endpoint_register(). In this case kernel will panic with
> accessing wrong pointer at qcom_mhi_qrtr_dl_callback():
>
> rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
> mhi_res->bytes_xferd);
>
> Because endpoint is not created yet.
> --------------------------------------------------------------
> So move mhi_prepare_for_transfer_autoqueue after endpoint creation
> to fix it.
>
> Fixes: a2e2cc0dbb11 ("net: qrtr: Start MHI channels during init")
> Signed-off-by: Maxim Kochetkov <mkochetkov@airspan.com>
Reviewed-by: Hemant Kumar <quic_hemantk@quicinc.com>
next prev parent reply other threads:[~2022-05-03 2:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-30 10:34 [PATCH] net: qrtr: start MHI channel after endpoit creation Maxim Kochetkov
2022-05-03 2:35 ` Hemant Kumar [this message]
2022-07-07 6:20 ` Maxim Kochetkov
2022-07-09 6:10 ` Manivannan Sadhasivam
2022-07-09 6:08 ` Manivannan Sadhasivam
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