linux-kernel - Re: [PATCH 2/2] keys: Remove unnecessary local variable from proc_keys

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Message-ID: <aP_OEQs2RcBNfn0M@kernel.org>
Date: Mon, 27 Oct 2025 21:54:57 +0200
From: Jarkko Sakkinen <jarkko@...nel.org>
To: Thorsten Blum <thorsten.blum@...ux.dev>
Cc: David Howells <dhowells@...hat.com>, Paul Moore <paul@...l-moore.com>,
	James Morris <jmorris@...ei.org>,
	"Serge E. Hallyn" <serge@...lyn.com>, keyrings@...r.kernel.org,
	linux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] keys: Remove unnecessary local variable from
 proc_keys_show

On Thu, Oct 23, 2025 at 04:32:33PM +0200, Thorsten Blum wrote:
> The local variable 'rc' is only used to temporary store the result of
> calling key_task_permission(). Use the result directly and remove the
> local variable.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
> ---
>  security/keys/proc.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/security/keys/proc.c b/security/keys/proc.c
> index 4f4e2c1824f1..39af57af2aad 100644
> --- a/security/keys/proc.c
> +++ b/security/keys/proc.c
> @@ -160,7 +160,6 @@ static int proc_keys_show(struct seq_file *m, void *v)
>  	char xbuf[16];
>  	short state;
>  	u64 timo;
> -	int rc;
>  
>  	struct keyring_search_context ctx = {
>  		.index_key		= key->index_key,
> @@ -188,8 +187,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
>  	}
>  
>  	/* check whether the current task is allowed to view the key */
> -	rc = key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW);
> -	if (rc < 0)
> +	if (key_task_permission(key_ref, ctx.cred, KEY_NEED_VIEW) < 0)
>  		return 0;

I absolutely dislike combining return value check to the call.

The old version documents that we ignore the return value, which
is convoluted in the new version.

>  
>  	now = ktime_get_real_seconds();
> -- 
> 2.51.0
> 

BR, Jarkko