Re: [PATCH] list debugging: warn when deleting a deleted entry

[Baruch Siach <baruch@tkos.co.il>]

Hi Dave,

Ping?
Any comment on this?

baruch

On Wed, May 05, 2010 at 11:14:29AM +0300, Baruch Siach wrote:
> Use the magic LIST_POISON* values to detect an incorrect use of list_del on a
> deleted entry. This DEBUG_LIST specific warning is easier to understand than
> the generic Oops message caused by LIST_POISON dereference.
> 
> Signed-off-by: Baruch Siach <baruch@tkos.co.il>
> ---
>  lib/list_debug.c |    6 ++++++
>  1 files changed, 6 insertions(+), 0 deletions(-)
> 
> diff --git a/lib/list_debug.c b/lib/list_debug.c
> index 1a39f4e..344c710 100644
> --- a/lib/list_debug.c
> +++ b/lib/list_debug.c
> @@ -43,6 +43,12 @@ EXPORT_SYMBOL(__list_add);
>   */
>  void list_del(struct list_head *entry)
>  {
> +	WARN(entry->next == LIST_POISON1,
> +		"list_del corruption, next is LIST_POISON1 (%p)\n",
> +		LIST_POISON1);
> +	WARN(entry->next != LIST_POISON1 && entry->prev == LIST_POISON2,
> +		"list_del corruption, prev is LIST_POISON2 (%p)\n",
> +		LIST_POISON2);
>  	WARN(entry->prev->next != entry,
>  		"list_del corruption. prev->next should be %p, "
>  		"but was %p\n", entry, entry->prev->next);
> -- 
> 1.7.0
> 

-- 
                                                     ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -