[PATCH][next] ACPICA: iASL: Replace zero-length array with flexible-array member

[PATCH][next] ACPICA: iASL: Replace zero-length array with flexible-array member

[Gustavo A. R. Silva]

There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 include/acpi/actbl2.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index 16847c8d9d5f..9ee4d1b39125 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -2319,7 +2319,7 @@ struct acpi_table_rgrt {
 	u16 version;
 	u8 image_type;
 	u8 reserved;
-	u8 image[0];
+	u8 image[];
 };
 
 /* image_type values */
-- 
2.27.0

Re: [PATCH][next] ACPICA: iASL: Replace zero-length array with flexible-array member

[Kees Cook]

On Wed, Feb 16, 2022 at 02:32:40PM -0600, Gustavo A. R. Silva wrote:
> There is a regular need in the kernel to provide a way to declare
> having a dynamically sized set of trailing elements in a structure.
> Kernel code should always use “flexible array members”[1] for these
> cases. The older style of one-element or zero-length arrays should
> no longer be used[2].
> 
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Link: https://github.com/KSPP/linux/issues/78
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH][next] ACPICA: iASL: Replace zero-length array with flexible-array member

[Rafael J. Wysocki]

On Wed, Feb 16, 2022 at 9:36 PM Kees Cook <keescook@chromium.org> wrote:
>
> On Wed, Feb 16, 2022 at 02:32:40PM -0600, Gustavo A. R. Silva wrote:
> > There is a regular need in the kernel to provide a way to declare
> > having a dynamically sized set of trailing elements in a structure.
> > Kernel code should always use “flexible array members”[1] for these
> > cases. The older style of one-element or zero-length arrays should
> > no longer be used[2].
> >
> > [1] https://en.wikipedia.org/wiki/Flexible_array_member
> > [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
> >
> > Link: https://github.com/KSPP/linux/issues/78
> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>
> Reviewed-by: Kees Cook <keescook@chromium.org>

I've created an upstream ACPICA pull request for this change, thanks!

Re: [PATCH][next] ACPICA: iASL: Replace zero-length array with flexible-array member

[Gustavo A. R. Silva]

On Fri, Feb 18, 2022 at 08:47:15PM +0100, Rafael J. Wysocki wrote:
> On Wed, Feb 16, 2022 at 9:36 PM Kees Cook <keescook@chromium.org> wrote:
> 
> I've created an upstream ACPICA pull request for this change, thanks!

Great.

Thanks, Rafael.
--
Gustavo