Re: [PATCH v3 2/2] slub: Add method to verify memory is notfreed.

[Christoph Lameter]

On Thu, 7 Jul 2011, greearb@xxxxxxxxxxxxxxx wrote:

> +	struct page *page;
> +	void *object = (void *)x;
> +	unsigned long flags;
> +	bool rv;
> +
> +	if (unlikely(ZERO_OR_NULL_PTR(x)))
> +		return false;
> +
> +	local_irq_save(flags);
> +
> +	page = virt_to_head_page(x);
> +	if (unlikely(!PageSlab(page))) {
> +		/* maybe it was from stack? */

Or it is a compound page that was used because the allocation was larger
than an order 2 alloc. Same result though.

> +		rv = true;
> +		goto out_unlock;
> +	}
> +
> +	slab_lock(page);
> +	if (on_freelist(page->slab, page, object)) {
> +		object_err(page->slab, page, object, "Object is on free-list");
> +		rv = false;
> +	} else {
> +		rv = true;
> +	}
> +	slab_unlock(page);
> +
> +out_unlock:
> +	local_irq_restore(flags);
> +	return rv;
> +}
> +EXPORT_SYMBOL(verify_mem_not_deleted);
> +#endif
> +
>  void kfree(const void *x)
>  {
>  	struct page *page;
>

Acked-by: Christoph Lameter <cl@xxxxxxxxx>

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