ASoC: SOF: ipc-msg-injector: Propagate write errors correctly

This code is supposed to propagate errors from simple_write_to_buffer()
or return -EFAULT if "size != count".  However "size" needs to be signed
for the code to work correctly and the case where "size == 0" is not
handled correctly.

Fixes: 066c67624d8c ("ASoC: SOF: ipc-msg-injector: Add support for IPC4 messages")
Fixes: 2f0b1b013bbc ("ASoC: SOF: debug: Add support for IPC message injection")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/Yph+Cd+JrfOH0i7z@kili
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/sof-client-ipc-msg-injector.c b/sound/soc/sof/sof-client-ipc-msg-injector.c
index 03490a4..030cb97 100644 (file)
--- a/sound/soc/sof/sof-client-ipc-msg-injector.c
+++ b/sound/soc/sof/sof-client-ipc-msg-injector.c
@@ -150,7 +150,7 @@ static ssize_t sof_msg_inject_dfs_write(struct file *file, const char __user *bu
 {
        struct sof_client_dev *cdev = file->private_data;
        struct sof_msg_inject_priv *priv = cdev->data;
-       size_t size;
+       ssize_t size;
        int ret;
 
        if (*ppos)
@@ -158,8 +158,10 @@ static ssize_t sof_msg_inject_dfs_write(struct file *file, const char __user *bu
 
        size = simple_write_to_buffer(priv->tx_buffer, priv->max_msg_size,
                                      ppos, buffer, count);
+       if (size < 0)
+               return size;
        if (size != count)
-               return size > 0 ? -EFAULT : size;
+               return -EFAULT;
 
        memset(priv->rx_buffer, 0, priv->max_msg_size);
 
@@ -179,7 +181,7 @@ static ssize_t sof_msg_inject_ipc4_dfs_write(struct file *file,
        struct sof_client_dev *cdev = file->private_data;
        struct sof_msg_inject_priv *priv = cdev->data;
        struct sof_ipc4_msg *ipc4_msg = priv->tx_buffer;
-       size_t size;
+       ssize_t size;
        int ret;
 
        if (*ppos)
@@ -192,8 +194,10 @@ static ssize_t sof_msg_inject_ipc4_dfs_write(struct file *file,
        size = simple_write_to_buffer(&ipc4_msg->header_u64,
                                      sizeof(ipc4_msg->header_u64),
                                      ppos, buffer, count);
+       if (size < 0)
+               return size;
        if (size != sizeof(ipc4_msg->header_u64))
-               return size > 0 ? -EFAULT : size;
+               return -EFAULT;
 
        count -= size;
        if (!count) {
@@ -201,8 +205,10 @@ static ssize_t sof_msg_inject_ipc4_dfs_write(struct file *file,
                size = simple_write_to_buffer(ipc4_msg->data_ptr,
                                              priv->max_msg_size, ppos, buffer,
                                              count);
+               if (size < 0)
+                       return size;
                if (size != count)
-                       return size > 0 ? -EFAULT : size;
+                       return -EFAULT;
        }
 
        ipc4_msg->data_size = count;