accel/qaic: Fix bootlog initialization ordering

As soon as we queue MHI buffers to receive the bootlog from the device,
we could be receiving data. Therefore all the resources needed to
process that data need to be setup prior to queuing the buffers.

We currently initialize some of the resources after queuing the buffers
which creates a race between the probe() and any data that comes back
from the device. If the uninitialized resources are accessed, we could
see page faults.

Fix the init ordering to close the race.

Fixes: 5f8df5c6def6 ("accel/qaic: Add bootlog debugfs")
Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Youssef Samir <youssef.abdulrahman@oss.qualcomm.com>
Reviewed-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Reviewed-by: Carl Vanderlip <carl.vanderlip@oss.qualcomm.com>
Signed-off-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251007115750.332169-1-youssef.abdulrahman@oss.qualcomm.com

diff --git a/drivers/accel/qaic/qaic_debugfs.c b/drivers/accel/qaic/qaic_debugfs.c
index a991b8198dc40e88225dc60fc4c3ff8cc005fba7..8dc4fe5bb560ed5a25872970f63e2c51988c9143 100644 (file)
--- a/drivers/accel/qaic/qaic_debugfs.c
+++ b/drivers/accel/qaic/qaic_debugfs.c
@@ -218,6 +218,9 @@ static int qaic_bootlog_mhi_probe(struct mhi_device *mhi_dev, const struct mhi_d
        if (ret)
                goto destroy_workqueue;
 
+       dev_set_drvdata(&mhi_dev->dev, qdev);
+       qdev->bootlog_ch = mhi_dev;
+
        for (i = 0; i < BOOTLOG_POOL_SIZE; i++) {
                msg = devm_kzalloc(&qdev->pdev->dev, sizeof(*msg), GFP_KERNEL);
                if (!msg) {
@@ -233,8 +236,6 @@ static int qaic_bootlog_mhi_probe(struct mhi_device *mhi_dev, const struct mhi_d
                        goto mhi_unprepare;
        }
 
-       dev_set_drvdata(&mhi_dev->dev, qdev);
-       qdev->bootlog_ch = mhi_dev;
        return 0;
 
 mhi_unprepare: