| Message ID | 20240512-qcom-pd-mapper-v8-1-5ecbb276fcc0@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | soc: qcom: add in-kernel pd-mapper implementation | expand |
Hi Dmitry, On 5/11/2024 2:56 PM, Dmitry Baryshkov wrote: ... > @@ -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); I'm not sure it is necessary to hold the the mutex during the qmi_txn_wait() since the only variable we are trying to protect is locator_addr. Wouldn't this delay other work like new/del server notifications if this qmi service is delayed or non-responsive? Thanks, Chris > > 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; > } >
On Thu, 6 Jun 2024 at 01:48, Chris Lew <quic_clew@quicinc.com> wrote: > > Hi Dmitry, > > On 5/11/2024 2:56 PM, Dmitry Baryshkov wrote: > ... > > @@ -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); > > I'm not sure it is necessary to hold the the mutex during the > qmi_txn_wait() since the only variable we are trying to protect is > locator_addr. > > Wouldn't this delay other work like new/del server notifications if this > qmi service is delayed or non-responsive? > I've verified, the addr is stored inside the message data by the enqueueing functions, so the locator_addr isn't referenced after the function returns. I'll reduce the locking scope.
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)
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(-)