Re: [PATCH] ehca: fix kthread_create() error check

[Heiko Carstens <heiko.carstens@de.ibm.com>]

> Index: 2.6-mm/drivers/infiniband/hw/ehca/ehca_irq.c
> ===================================================================
> --- 2.6-mm.orig/drivers/infiniband/hw/ehca/ehca_irq.c
> +++ 2.6-mm/drivers/infiniband/hw/ehca/ehca_irq.c
> @@ -670,11 +670,13 @@ static int comp_pool_callback(struct not
>  {
>  	unsigned int cpu = (unsigned long)hcpu;
>  	struct ehca_cpu_comp_task *cct;
> +	struct task_struct *task;
> 
>  	switch (action) {
>  	case CPU_UP_PREPARE:
>  		ehca_gen_dbg("CPU: %x (CPU_PREPARE)", cpu);
> -		if(!create_comp_task(pool, cpu)) {
> +		task = create_comp_task(pool, cpu);
> +		if (IS_ERR(task)) {
>  			ehca_gen_err("Can't create comp_task for cpu: %x", cpu);
>  			return NOTIFY_BAD;
>  		}

If this fails then the code will crash on CPU_UP_CANCELED. Because of
kthread_bind(cct->task,...). cct->task would be just the encoded error
number.

> @@ -730,7 +732,7 @@ int ehca_create_comp_pool(void)
> 
>  	for_each_online_cpu(cpu) {
>  		task = create_comp_task(pool, cpu);
> -		if (task) {
> +		if (!IS_ERR(task)) {
>  			kthread_bind(task, cpu);
>  			wake_up_process(task);
>  		}

So you silently ignore errors and the module loads anyway?