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

From: Heiko Carstens
Date: Thu Dec 21 2006 - 16:22:25 EST


> 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?
-
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