diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c index 4555d678fadda..6dd5b9614452b 100644 --- a/drivers/mailbox/mailbox-test.c +++ b/drivers/mailbox/mailbox-test.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -38,6 +39,7 @@ struct mbox_test_device { char *signal; char *message; spinlock_t lock; + struct mutex mutex; wait_queue_head_t waitq; struct fasync_struct *async_queue; struct dentry *root_debugfs_dir; @@ -110,6 +112,8 @@ static ssize_t mbox_test_message_write(struct file *filp, return -EINVAL; } + mutex_lock(&tdev->mutex); + tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL); if (!tdev->message) return -ENOMEM; @@ -144,6 +148,8 @@ static ssize_t mbox_test_message_write(struct file *filp, kfree(tdev->message); tdev->signal = NULL; + mutex_unlock(&tdev->mutex); + return ret < 0 ? ret : count; } @@ -392,6 +398,7 @@ static int mbox_test_probe(struct platform_device *pdev) platform_set_drvdata(pdev, tdev); spin_lock_init(&tdev->lock); + mutex_init(&tdev->mutex); if (tdev->rx_channel) { tdev->rx_buffer = devm_kzalloc(&pdev->dev,