LinuxLists.cc - [PATCH] mm/memcg: Annotate struct mem_cgroup_threshold_ary with __counted

2023-09-22 23:18:47

Subject: [PATCH] mm/memcg: Annotate struct mem_cgroup_threshold_ary with __counted_by

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 <[email protected]>
Cc: Shakeel Butt <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: "Matthew Wilcox (Oracle)" <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
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

2023-09-23 03:04:07

by Shakeel Butt

[permalink] [raw]

Subject: Re: [PATCH] mm/memcg: Annotate struct mem_cgroup_threshold_ary with __counted_by

On Fri, Sep 22, 2023 at 10:53 AM Kees Cook <[email protected]> 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 <[email protected]>
> Cc: Shakeel Butt <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: "Matthew Wilcox (Oracle)" <[email protected]>
> Signed-off-by: Kees Cook <[email protected]>

Acked-by: Shakeel Butt <[email protected]>

2023-09-23 04:35:39

by Roman Gushchin

[permalink] [raw]

Subject: Re: [PATCH] mm/memcg: Annotate struct mem_cgroup_threshold_ary with __counted_by

2023-09-23 09:05:39

by Gustavo A. R. Silva

[permalink] [raw]

Subject: Re: [PATCH] mm/memcg: Annotate struct mem_cgroup_threshold_ary with __counted_by

On Fri, Sep 22, 2023 at 10:53:28AM -0700, 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 <[email protected]>
> Cc: Shakeel Butt <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: "Matthew Wilcox (Oracle)" <[email protected]>
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> ---
> 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
>
>

2023-09-25 07:25:50

by Michal Hocko

[permalink] [raw]

Subject: Re: [PATCH] mm/memcg: Annotate struct mem_cgroup_threshold_ary with __counted_by

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 <[email protected]>
> Cc: Shakeel Butt <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: "Matthew Wilcox (Oracle)" <[email protected]>
> Signed-off-by: Kees Cook <[email protected]>

Acked-by: Michal Hocko <[email protected]>

> ---
> 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