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From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Sun, 12 May 2024 00:56:03 +0300
Subject: [PATCH v8 1/5] soc: qcom: pdr: protect locator_addr with the main
 mutex
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Message-Id: <20240512-qcom-pd-mapper-v8-1-5ecbb276fcc0@linaro.org>
References: <20240512-qcom-pd-mapper-v8-0-5ecbb276fcc0@linaro.org>
In-Reply-To: <20240512-qcom-pd-mapper-v8-0-5ecbb276fcc0@linaro.org>
To: 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>, 
 Steev Klimaszewski <steev@kali.org>, 
 Alexey Minnekhanov <alexeymin@postmarketos.org>, 
 Neil Armstrong <neil.armstrong@linaro.org>

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
Tested-by: Steev Klimaszewski <steev@kali.org>
Tested-by: Alexey Minnekhanov <alexeymin@postmarketos.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/soc/qcom/pdr_interface.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c
index a1b6a4081dea..e014dd2d8ab3 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 = {
@@ -365,6 +365,7 @@ static int pdr_get_domain_list(struct servreg_get_domain_list_req *req,
 	if (ret < 0)
 		return ret;
 
+	mutex_lock(&pdr->lock);
 	ret = qmi_send_request(&pdr->locator_hdl,
 			       &pdr->locator_addr,
 			       &txn, SERVREG_GET_DOMAIN_LIST_REQ,
@@ -373,15 +374,16 @@ static int pdr_get_domain_list(struct servreg_get_domain_list_req *req,
 			       req);
 	if (ret < 0) {
 		qmi_txn_cancel(&txn);
-		return ret;
+		goto err_unlock;
 	}
 
 	ret = qmi_txn_wait(&txn, 5 * HZ);
 	if (ret < 0) {
 		pr_err("PDR: %s get domain list txn wait failed: %d\n",
 		       req->service_name, ret);
-		return ret;
+		goto err_unlock;
 	}
+	mutex_unlock(&pdr->lock);
 
 	if (resp->resp.result != QMI_RESULT_SUCCESS_V01) {
 		pr_err("PDR: %s get domain list failed: 0x%x\n",
@@ -390,6 +392,11 @@ static int pdr_get_domain_list(struct servreg_get_domain_list_req *req,
 	}
 
 	return 0;
+
+err_unlock:
+	mutex_unlock(&pdr->lock);
+
+	return ret;
 }
 
 static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds)

-- 
2.39.2