On Fri 22-09-23 10:53:28, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct
> mem_cgroup_threshold_ary.
>
> [1]
> https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Cc: Shakeel Butt <shake...@google.com>
> Cc: Roman Gushchin <roman.gushc...@linux.dev>
> Cc: Johannes Weiner <han...@cmpxchg.org>
> Cc: Michal Hocko <mho...@suse.com>
> Cc: "Matthew Wilcox (Oracle)" <wi...@infradead.org>
> Signed-off-by: Kees Cook <keesc...@chromium.org>
Acked-by: Michal Hocko <mho...@suse.com>
> ---
> include/linux/memcontrol.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 45d0c10e86cc..e0cfab58ab71 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -143,7 +143,7 @@ struct mem_cgroup_threshold_ary {
> /* Size of entries[] */
> unsigned int size;
> /* Array of thresholds */
> - struct mem_cgroup_threshold entries[];
> + struct mem_cgroup_threshold entries[] __counted_by(size);
> };
>
> struct mem_cgroup_thresholds {
> --
> 2.34.1
--
Michal Hocko
SUSE Labs
