Re: [PATCH v2 0/2] bitmap: Fix return values to be unsigned

[Yury Norov]

On Tue, May 17, 2022 at 02:22:32PM -0700, Kees Cook wrote:
> Hi,
> 
> As mentioned in the last patch:
> 
> Both nodemask and bitmap routines had mixed return values that provided
> potentially signed results that could never happen. This was leading to
> the compiler getting confusing about the range of possible return values
> (it was thinking things could be negative where they could not be). Fix
> all the nodemask and bitmap routines that should be returning unsigned
> (or bool) values. Silences GCC 12 warnings:
> 
>  mm/swapfile.c: In function ‘setup_swap_info’:
>  mm/swapfile.c:2291:47: error: array subscript -1 is below array bounds of ‘struct plist_node[]’ [-Werror=array-bounds]
>   2291 |                                 p->avail_lists[i].prio = 1;
>        |                                 ~~~~~~~~~~~~~~^~~
>  In file included from mm/swapfile.c:16:
>  ./include/linux/swap.h:292:27: note: while referencing ‘avail_lists’
>    292 |         struct plist_node avail_lists[]; /*
>        |                           ^~~~~~~~~~~
> 
> This splits up the patch into the bitmap and nodemask halves, and drops
> a needless change to the random node helper.
> 
> I note that Alexey and Rasmus touched on this area in the past, fixing
> up node ids to be unsigned:
> 
> ce0725f78a56 ("numa: make "nr_online_nodes" unsigned int")
> b9726c26dc21 ("numa: make "nr_node_ids" unsigned int")
> 33c4fa8c6763 ("linux/nodemask.h: update bitmap wrappers to take unsigned int")
> 
> If anyone else would like to carry this, please let me know. I'm happy
> to carry it in my tree.

I think it should go thru my tree, if no objections.
 
> -Kees
> 
> Kees Cook (2):
>   bitmap: Fix return values to be unsigned
>   nodemask: Fix return values to be unsigned

Can you please also add patch for tools?

Thanks,
Yury

>  include/linux/bitmap.h   | 14 +++++++-------
>  include/linux/nodemask.h | 38 +++++++++++++++++++-------------------
>  lib/bitmap.c             | 28 ++++++++++++++--------------
>  lib/nodemask.c           |  2 +-
>  4 files changed, 41 insertions(+), 41 deletions(-)
> 
> -- 
> 2.32.0