[PATCH] audit: wait_for_auditd rework for readability

[PATCH] audit: wait_for_auditd rework for readability

[Eric Paris]

We had some craziness with signed to unsigned long casting which appears
wholely unnecessary.  Just use signed long.  Even though 2 values of the
math equation are unsigned longs the result is expected to be a signed
long.  So why keep casting the result to signed long?  Just make it
signed long and use it.

We also remove the needless "timeout" variable.  We already have the
stack "sleep_time" variable.  Just use that...

Signed-off-by: Eric Paris <eparis@redhat.com>
---
 kernel/audit.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 3c2ce3c..9d433b3 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1289,21 +1289,20 @@ static inline void audit_get_stamp(struct audit_context *ctx,
 /*
  * Wait for auditd to drain the queue a little
  */
-static unsigned long wait_for_auditd(unsigned long sleep_time)
+static long wait_for_auditd(long sleep_time)
 {
-	unsigned long timeout = sleep_time;
 	DECLARE_WAITQUEUE(wait, current);
 	set_current_state(TASK_UNINTERRUPTIBLE);
 	add_wait_queue_exclusive(&audit_backlog_wait, &wait);
 
 	if (audit_backlog_limit &&
 	    skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
-		timeout = schedule_timeout(sleep_time);
+		sleep_time = schedule_timeout(sleep_time);
 
 	__set_current_state(TASK_RUNNING);
 	remove_wait_queue(&audit_backlog_wait, &wait);
 
-	return timeout;
+	return sleep_time;
 }
 
 /**
@@ -1347,13 +1346,12 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
 	while (audit_backlog_limit
 	       && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
 		if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
-			unsigned long sleep_time;
+			long sleep_time;
 
-			sleep_time = timeout_start + audit_backlog_wait_time -
-					jiffies;
-			if ((long)sleep_time > 0) {
+			sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
+			if (sleep_time > 0) {
 				sleep_time = wait_for_auditd(sleep_time);
-				if ((long)sleep_time > 0)
+				if (sleep_time > 0)
 					continue;
 			}
 		}
-- 
1.8.4.2

Re: [PATCH] audit: wait_for_auditd rework for readability

[Richard Guy Briggs]

On 14/01/13, Eric Paris wrote:
> We had some craziness with signed to unsigned long casting which appears
> wholely unnecessary.  Just use signed long.  Even though 2 values of the
> math equation are unsigned longs the result is expected to be a signed
> long.  So why keep casting the result to signed long?  Just make it
> signed long and use it.
> 
> We also remove the needless "timeout" variable.  We already have the
> stack "sleep_time" variable.  Just use that...
> 
> Signed-off-by: Eric Paris <eparis@redhat.com>

Ack.

> ---
>  kernel/audit.c | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)
> 
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 3c2ce3c..9d433b3 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1289,21 +1289,20 @@ static inline void audit_get_stamp(struct audit_context *ctx,
>  /*
>   * Wait for auditd to drain the queue a little
>   */
> -static unsigned long wait_for_auditd(unsigned long sleep_time)
> +static long wait_for_auditd(long sleep_time)
>  {
> -	unsigned long timeout = sleep_time;
>  	DECLARE_WAITQUEUE(wait, current);
>  	set_current_state(TASK_UNINTERRUPTIBLE);
>  	add_wait_queue_exclusive(&audit_backlog_wait, &wait);
>  
>  	if (audit_backlog_limit &&
>  	    skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
> -		timeout = schedule_timeout(sleep_time);
> +		sleep_time = schedule_timeout(sleep_time);
>  
>  	__set_current_state(TASK_RUNNING);
>  	remove_wait_queue(&audit_backlog_wait, &wait);
>  
> -	return timeout;
> +	return sleep_time;
>  }
>  
>  /**
> @@ -1347,13 +1346,12 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
>  	while (audit_backlog_limit
>  	       && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
>  		if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
> -			unsigned long sleep_time;
> +			long sleep_time;
>  
> -			sleep_time = timeout_start + audit_backlog_wait_time -
> -					jiffies;
> -			if ((long)sleep_time > 0) {
> +			sleep_time = timeout_start + audit_backlog_wait_time - jiffies;
> +			if (sleep_time > 0) {
>  				sleep_time = wait_for_auditd(sleep_time);
> -				if ((long)sleep_time > 0)
> +				if (sleep_time > 0)
>  					continue;
>  			}
>  		}
> -- 
> 1.8.4.2
> 

- RGB

--
Richard Guy Briggs <rbriggs@redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545