[PATCH] pstore: no need to check return value of debugfs_create functions

[PATCH] pstore: no need to check return value of debugfs_create functions

[Greg Kroah-Hartman]

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Kees Cook <keescook@chromium.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/pstore/ftrace.c | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
index b8a0931568f8..fd9468928bef 100644
--- a/fs/pstore/ftrace.c
+++ b/fs/pstore/ftrace.c
@@ -120,27 +120,13 @@ static struct dentry *pstore_ftrace_dir;
 
 void pstore_register_ftrace(void)
 {
-	struct dentry *file;
-
 	if (!psinfo->write)
 		return;
 
 	pstore_ftrace_dir = debugfs_create_dir("pstore", NULL);
-	if (!pstore_ftrace_dir) {
-		pr_err("%s: unable to create pstore directory\n", __func__);
-		return;
-	}
-
-	file = debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir,
-				   NULL, &pstore_knob_fops);
-	if (!file) {
-		pr_err("%s: unable to create record_ftrace file\n", __func__);
-		goto err_file;
-	}
 
-	return;
-err_file:
-	debugfs_remove(pstore_ftrace_dir);
+	debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, NULL,
+			    &pstore_knob_fops);
 }
 
 void pstore_unregister_ftrace(void)
-- 
2.22.0

Re: [PATCH] pstore: no need to check return value of debugfs_create functions

[Kees Cook]

On Wed, Jun 12, 2019 at 05:20:33PM +0200, Greg Kroah-Hartman wrote:
> When calling debugfs functions, there is no need to ever check the
> return value.  The function can work or not, but the code logic should
> never do something different based on this.
> 
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Anton Vorontsov <anton@enomsg.org>
> Cc: Colin Cross <ccross@android.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks; applied to my for-next/pstore tree.

-Kees

> ---
>  fs/pstore/ftrace.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c
> index b8a0931568f8..fd9468928bef 100644
> --- a/fs/pstore/ftrace.c
> +++ b/fs/pstore/ftrace.c
> @@ -120,27 +120,13 @@ static struct dentry *pstore_ftrace_dir;
>  
>  void pstore_register_ftrace(void)
>  {
> -	struct dentry *file;
> -
>  	if (!psinfo->write)
>  		return;
>  
>  	pstore_ftrace_dir = debugfs_create_dir("pstore", NULL);
> -	if (!pstore_ftrace_dir) {
> -		pr_err("%s: unable to create pstore directory\n", __func__);
> -		return;
> -	}
> -
> -	file = debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir,
> -				   NULL, &pstore_knob_fops);
> -	if (!file) {
> -		pr_err("%s: unable to create record_ftrace file\n", __func__);
> -		goto err_file;
> -	}
>  
> -	return;
> -err_file:
> -	debugfs_remove(pstore_ftrace_dir);
> +	debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, NULL,
> +			    &pstore_knob_fops);
>  }
>  
>  void pstore_unregister_ftrace(void)
> -- 
> 2.22.0
> 

-- 
Kees Cook