accel/qaic: Fix bootlog initialization ordering

[ Upstream commit fd6e385528d8f85993b7bfc6430576136bb14c65 ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/accel/qaic/qaic_debugfs.c b/drivers/accel/qaic/qaic_debugfs.c
index 20b653d99e524a5c0d451b68b66ffcd10547377d..5ed49daaf541f4f432b2377bd250c3683bbc091e 100644 (file)
--- a/drivers/accel/qaic/qaic_debugfs.c
+++ b/drivers/accel/qaic/qaic_debugfs.c
@@ -251,6 +251,9 @@ 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) {
@@ -266,8 +269,6 @@ 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: