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    net: qrtr: start MHI channel after endpoit creation · 68a838b8
    Maxim Kochetkov 提交于
    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: a2e2cc0d ("net: qrtr: Start MHI channels during init")
    Signed-off-by: NMaxim Kochetkov <fido_max@inbox.ru>
    Reviewed-by: NHemant Kumar <quic_hemantk@quicinc.com>
    Reviewed-by: NManivannan Sadhasivam <mani@kernel.org>
    Reviewed-by: NLoic Poulain <loic.poulain@linaro.org>
    Signed-off-by: NDavid S. Miller <davem@davemloft.net>
    68a838b8
mhi.c 3.0 KB