From: Chris Lew <quic_clew@quicinc.com>
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konrad.dybcio@linaro.org>,
Sibi Sankar <quic_sibis@quicinc.com>,
Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: <linux-arm-msm@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-remoteproc@vger.kernel.org>,
Johan Hovold <johan+linaro@kernel.org>,
Xilin Wu <wuxilin123@gmail.com>,
Bryan O'Donoghue <bryan.odonoghue@linaro.org>,
Neil Armstrong <neil.armstrong@linaro.org>
Subject: Re: [PATCH v7 1/6] soc: qcom: pdr: protect locator_addr with the main mutex
Date: Thu, 25 Apr 2024 12:30:07 -0700 [thread overview]
Message-ID: <d71c677f-eff7-2bc4-4328-38e4d83e1115@quicinc.com> (raw)
In-Reply-To: <20240424-qcom-pd-mapper-v7-1-05f7fc646e0f@linaro.org>
On 4/24/2024 2:27 AM, Dmitry Baryshkov wrote:
> If the service locator server is restarted fast enough, the PDR can
> rewrite locator_addr fields concurrently. Protect them by placing
> modification of those fields under the main pdr->lock.
>
> Fixes: fbe639b44a82 ("soc: qcom: Introduce Protection Domain Restart helpers")
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
> drivers/soc/qcom/pdr_interface.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c
> index a1b6a4081dea..19cfe4b41235 100644
> --- a/drivers/soc/qcom/pdr_interface.c
> +++ b/drivers/soc/qcom/pdr_interface.c
> @@ -76,12 +76,12 @@ static int pdr_locator_new_server(struct qmi_handle *qmi,
> locator_hdl);
> struct pdr_service *pds;
>
> + mutex_lock(&pdr->lock);
> /* Create a local client port for QMI communication */
> pdr->locator_addr.sq_family = AF_QIPCRTR;
> pdr->locator_addr.sq_node = svc->node;
> pdr->locator_addr.sq_port = svc->port;
>
> - mutex_lock(&pdr->lock);
> pdr->locator_init_complete = true;
> mutex_unlock(&pdr->lock);
>
> @@ -104,10 +104,10 @@ static void pdr_locator_del_server(struct qmi_handle *qmi,
>
> mutex_lock(&pdr->lock);
> pdr->locator_init_complete = false;
> - mutex_unlock(&pdr->lock);
>
> pdr->locator_addr.sq_node = 0;
> pdr->locator_addr.sq_port = 0;
> + mutex_unlock(&pdr->lock);
> }
>
> static const struct qmi_ops pdr_locator_ops = {
>
These two functions are provided as qmi_ops handlers in pdr_locator_ops.
Aren't they serialized in the qmi handle's workqueue since it as an
ordered_workqueue? Even in a fast pdr scenario I don't think we would
see a race condition between these two functions.
The other access these two functions do race against is in the
pdr_notifier_work. I think you would need to protect locator_addr in
pdr_get_domain_list since the qmi_send_request there uses
'pdr->locator_addr'.
Thanks!
Chris
next prev parent reply other threads:[~2024-04-25 19:30 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 9:27 [PATCH v7 0/6] soc: qcom: add in-kernel pd-mapper implementation Dmitry Baryshkov
2024-04-24 9:27 ` [PATCH v7 1/6] soc: qcom: pdr: protect locator_addr with the main mutex Dmitry Baryshkov
2024-04-25 19:30 ` Chris Lew [this message]
2024-05-11 21:52 ` Dmitry Baryshkov
2024-04-24 9:27 ` [PATCH v7 2/6] soc: qcom: pdr: fix parsing of domains lists Dmitry Baryshkov
2024-04-24 9:27 ` [PATCH v7 3/6] soc: qcom: pdr: extract PDR message marshalling data Dmitry Baryshkov
2024-04-24 9:28 ` [PATCH v7 4/6] soc: qcom: qmi: add a way to remove running service Dmitry Baryshkov
2024-04-25 20:57 ` Chris Lew
2024-04-24 9:28 ` [PATCH v7 5/6] soc: qcom: add pd-mapper implementation Dmitry Baryshkov
2024-04-26 13:48 ` Alexey Minnekhanov
2024-04-26 23:25 ` Chris Lew
2024-04-24 9:28 ` [PATCH v7 6/6] remoteproc: qcom: enable in-kernel PD mapper Dmitry Baryshkov
2024-04-27 1:03 ` Chris Lew
2024-04-27 1:36 ` Dmitry Baryshkov
2024-04-30 19:10 ` Chris Lew
2024-04-25 7:08 ` [PATCH v7 0/6] soc: qcom: add in-kernel pd-mapper implementation Steev Klimaszewski
2024-04-25 7:10 ` Dmitry Baryshkov
2024-04-26 14:02 ` Alexey Minnekhanov
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