Re: [kernel-hardening] [PATCH v2 1/2] fork: free vmapped stacks in cache when cpus are offline

[Eric Biggers]

Hi Hoeun,

On Thu, Feb 09, 2017 at 01:03:46PM +0900, Hoeun Ryu wrote:
> +static int free_vm_stack_cache(unsigned int cpu)
> +{
> +	int i;
> +
> +	for (i = 0; i < NR_CACHED_STACKS; i++) {
> +		struct vm_struct *vm_stack = this_cpu_read(cached_stacks[i]);
> +		if (!vm_stack)
> +			continue;
> +
> +		vfree(vm_stack->addr);
> +		this_cpu_write(cached_stacks[i], NULL);
> +	}
> +
> +	return 0;
> +}

Doesn't this need to free the stacks for the 'cpu' that's passed in, instead of
"this" CPU?

- Eric