[PATCH] ASoC: SOF: debug: delete sof_dfsentry_write()

[PATCH] ASoC: SOF: debug: delete sof_dfsentry_write()

[Dan Carpenter]

The sof_dfsentry_write() function used to have a purpose but now it is a
no-op.  It allocates a zeroed buffer, copies at least one byte of data
to it, and then frees it without doing anything.  Just delete the
function.

Fixes: 6e9548cdb30e ("ASoC: SOF: Convert the generic IPC flood test into SOF client")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
From review.  Not tested.

 sound/soc/sof/debug.c | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/sound/soc/sof/debug.c b/sound/soc/sof/debug.c
index c5d797e97c02..00abc2000bfb 100644
--- a/sound/soc/sof/debug.c
+++ b/sound/soc/sof/debug.c
@@ -19,24 +19,6 @@
 #include "sof-priv.h"
 #include "ops.h"
 
-static ssize_t sof_dfsentry_write(struct file *file, const char __user *buffer,
-				  size_t count, loff_t *ppos)
-{
-	size_t size;
-	char *string;
-	int ret;
-
-	string = kzalloc(count+1, GFP_KERNEL);
-	if (!string)
-		return -ENOMEM;
-
-	size = simple_write_to_buffer(string, count, ppos, buffer, count);
-	ret = size;
-
-	kfree(string);
-	return ret;
-}
-
 static ssize_t sof_dfsentry_read(struct file *file, char __user *buffer,
 				 size_t count, loff_t *ppos)
 {
@@ -126,7 +108,6 @@ static const struct file_operations sof_dfs_fops = {
 	.open = simple_open,
 	.read = sof_dfsentry_read,
 	.llseek = default_llseek,
-	.write = sof_dfsentry_write,
 };
 
 /* create FS entry for debug files that can expose DSP memories, registers */
-- 
2.35.1

Re: [PATCH] ASoC: SOF: debug: delete sof_dfsentry_write()

[Péter Ujfalusi]

Hi Dan,

On 06/07/2022 10:28, Dan Carpenter wrote:
> The sof_dfsentry_write() function used to have a purpose but now it is a
> no-op.  It allocates a zeroed buffer, copies at least one byte of data
> to it, and then frees it without doing anything.  Just delete the
> function.
> 
> Fixes: 6e9548cdb30e ("ASoC: SOF: Convert the generic IPC flood test into SOF client")

it is not really a fix but rather complements that commit...

> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> From review.  Not tested.
> 
>  sound/soc/sof/debug.c | 19 -------------------
>  1 file changed, 19 deletions(-)
> 
> diff --git a/sound/soc/sof/debug.c b/sound/soc/sof/debug.c
> index c5d797e97c02..00abc2000bfb 100644
> --- a/sound/soc/sof/debug.c
> +++ b/sound/soc/sof/debug.c
> @@ -19,24 +19,6 @@
>  #include "sof-priv.h"
>  #include "ops.h"
>  
> -static ssize_t sof_dfsentry_write(struct file *file, const char __user *buffer,
> -				  size_t count, loff_t *ppos)
> -{
> -	size_t size;
> -	char *string;
> -	int ret;
> -
> -	string = kzalloc(count+1, GFP_KERNEL);
> -	if (!string)
> -		return -ENOMEM;
> -
> -	size = simple_write_to_buffer(string, count, ppos, buffer, count);
> -	ret = size;
> -
> -	kfree(string);
> -	return ret;
> -}
> -
>  static ssize_t sof_dfsentry_read(struct file *file, char __user *buffer,
>  				 size_t count, loff_t *ppos)
>  {
> @@ -126,7 +108,6 @@ static const struct file_operations sof_dfs_fops = {
>  	.open = simple_open,
>  	.read = sof_dfsentry_read,
>  	.llseek = default_llseek,
> -	.write = sof_dfsentry_write,

I might add a check in snd_sof_debugfs_buf_item() to disallow write
permission for the file. I know, we only use 0444 for the remaining
files. It might be too paranoid, I guess.

>  };
>  
>  /* create FS entry for debug files that can expose DSP memories, registers */

-- 
Péter