soc: qcom: pmic_glink: don't traverse clients list without a lock

Take the client_lock before traversing the clients list at the
pmic_glink_state_notify_clients() function. This is required to keep the
list traversal safe from concurrent modification.

Fixes: 58ef4ece1e41 ("soc: qcom: pmic_glink: Introduce base PMIC GLINK driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Tested-by: Xilin Wu <wuxilin123@gmail.com> # on QCS8550 AYN Odin 2
Link: https://lore.kernel.org/r/20240403-pmic-glink-fix-clients-v2-1-aed4e02baacc@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
index f913e9bd57ed4a7aa6d1b99d27a40552713b2536..2b2cdf4796542e6e7fc4cf10af3d11be0106aa47 100644 (file)
--- a/drivers/soc/qcom/pmic_glink.c
+++ b/drivers/soc/qcom/pmic_glink.c
@@ -115,10 +115,12 @@ static int pmic_glink_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
 
        hdr = data;
 
+       mutex_lock(&pg->client_lock);
        list_for_each_entry(client, &pg->clients, node) {
                if (client->id == le32_to_cpu(hdr->owner))
                        client->cb(data, len, client->priv);
        }
+       mutex_unlock(&pg->client_lock);
 
        return 0;
 }
@@ -168,8 +170,10 @@ static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
        }
 
        if (new_state != pg->client_state) {
+               mutex_lock(&pg->client_lock);
                list_for_each_entry(client, &pg->clients, node)
                        client->pdr_notify(client->priv, new_state);
+               mutex_unlock(&pg->client_lock);
                pg->client_state = new_state;
        }
 }