Restructure error handling in rcu_torture_fwd_prog_init() to provide
cleaner allocation failure paths. The current code checks both
allocations in a single condition, making error handling less
efficient and clear.

The improved approach:
- Check rfp allocation immediately and return early on failure
- Separately handle fwd_prog_tasks allocation failure with proper
  cleanup
- Remove redundant kfree(fwd_prog_tasks) since it would be NULL on
  failure

Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
---
Changes in v2:
- Fixed word wrapping in commit message to follow kernel guidelines
---
 kernel/rcu/rcutorture.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 807fbf6123a7..6af0d207adba 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -2995,11 +2995,11 @@ static int __init rcu_torture_fwd_prog_init(void)
 	if (fwd_progress_div <= 0)
 		fwd_progress_div = 4;
 	rfp = kcalloc(fwd_progress, sizeof(*rfp), GFP_KERNEL);
+	if (!rfp)
+		return -ENOMEM;
 	fwd_prog_tasks = kcalloc(fwd_progress, sizeof(*fwd_prog_tasks), GFP_KERNEL);
-	if (!rfp || !fwd_prog_tasks) {
+	if (!fwd_prog_tasks) {
 		kfree(rfp);
-		kfree(fwd_prog_tasks);
-		fwd_prog_tasks = NULL;
 		fwd_progress = 0;
 		return -ENOMEM;
 	}
-- 
2.34.1

On Wed, Sep 10, 2025 at 02:58:20PM +0530, Kaushlendra Kumar wrote:
> Restructure error handling in rcu_torture_fwd_prog_init() to provide
> cleaner allocation failure paths. The current code checks both
> allocations in a single condition, making error handling less
> efficient and clear.
> 
> The improved approach:
> - Check rfp allocation immediately and return early on failure
> - Separately handle fwd_prog_tasks allocation failure with proper
>   cleanup
> - Remove redundant kfree(fwd_prog_tasks) since it would be NULL on
>   failure

First, thank you for your interest in Linux-kernel RCU!

However, you lost me on this one.  Please see below.

> Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
> ---
> Changes in v2:
> - Fixed word wrapping in commit message to follow kernel guidelines
> ---
>  kernel/rcu/rcutorture.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
> index 807fbf6123a7..6af0d207adba 100644
> --- a/kernel/rcu/rcutorture.c
> +++ b/kernel/rcu/rcutorture.c
> @@ -2995,11 +2995,11 @@ static int __init rcu_torture_fwd_prog_init(void)
>  	if (fwd_progress_div <= 0)
>  		fwd_progress_div = 4;
>  	rfp = kcalloc(fwd_progress, sizeof(*rfp), GFP_KERNEL);
> +	if (!rfp)
> +		return -ENOMEM;

Don't we still need to set fwd_progress to zero?

>  	fwd_prog_tasks = kcalloc(fwd_progress, sizeof(*fwd_prog_tasks), GFP_KERNEL);

Although this change does avoid the doomed kcalloc() attempt, why are
we optimizing an infrequent failure case?

> -	if (!rfp || !fwd_prog_tasks) {
> +	if (!fwd_prog_tasks) {
>  		kfree(rfp);
> -		kfree(fwd_prog_tasks);

Invoking kfree() on a NULL pointer is a well-defined no-op.

> -		fwd_prog_tasks = NULL;
>  		fwd_progress = 0;
>  		return -ENOMEM;
>  	}

I don't see where this is helping the common-case success path, nor am
I seeing need need to optimize this initialization-time-only code path.
Adding the zeroing of fwd_progress will result in a net increase in the
number of lines of code.

So what am I missing here?

							Thanx, Paul