[2/9] drm/amdgpu/discovery: Annotate struct ip_hw_instance with __counted_by

Commit Message

Kees Cook Sept. 22, 2023, 5:32 p.m. UTC

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 ip_hw_instance.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Alex Deucher <[e-mail]>
Cc: "Christian König" <[e-mail]>
Cc: "Pan, Xinhui" <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Cc: Hawking Zhang <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Kees Cook <[e-mail]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alex Deucher Sept. 22, 2023, 5:42 p.m. UTC | #1

On Fri, Sep 22, 2023 at 1:33 PM Kees Cook <[e-mail]> 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 ip_hw_instance.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Alex Deucher <[e-mail]>
> Cc: "Christian König" <[e-mail]>
> Cc: "Pan, Xinhui" <[e-mail]>
> Cc: David Airlie <[e-mail]>
> Cc: Daniel Vetter <[e-mail]>
> Cc: Hawking Zhang <[e-mail]>
> Cc: [e-mail]
> Cc: [e-mail]
> Signed-off-by: Kees Cook <[e-mail]>

Acked-by: Alex Deucher <[e-mail]>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> index d1bc7b212520..be4c97a3d7bf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> @@ -662,7 +662,7 @@ struct ip_hw_instance {
>         u8  harvest;
>
>         int num_base_addresses;
> -       u32 base_addr[];
> +       u32 base_addr[] __counted_by(num_base_addresses);
>  };
>
>  struct ip_hw_id {
> --
> 2.34.1
>

Gustavo A. R. Silva Sept. 23, 2023, 2:14 a.m. UTC | #2

On 9/22/23 11:32, 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 ip_hw_instance.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Alex Deucher <[e-mail]>
> Cc: "Christian König" <[e-mail]>
> Cc: "Pan, Xinhui" <[e-mail]>
> Cc: David Airlie <[e-mail]>
> Cc: Daniel Vetter <[e-mail]>
> Cc: Hawking Zhang <[e-mail]>
> Cc: [e-mail]
> Cc: [e-mail]
> Signed-off-by: Kees Cook <[e-mail]>

Reviewed-by: Gustavo A. R. Silva <[e-mail]>

Thanks

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
index d1bc7b212520..be4c97a3d7bf 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
@@ -662,7 +662,7 @@  struct ip_hw_instance {
 	u8  harvest;
 
 	int num_base_addresses;
-	u32 base_addr[];
+	u32 base_addr[] __counted_by(num_base_addresses);
 };
 
 struct ip_hw_id {