Re: [PATCH] sh: fix fallout from ZERO_PAGE consolidation

[John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>]

Hi,

On Fri, 2026-04-17 at 13:32 +0300, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> 
> Consolidation of empty_zero_page declarations broke boot on sh.
> 
> sh stores its initial boot parameters in a page reserved in
> arch/sh/kernel/head_32.S. Before commit 6215d9f4470f ("arch, mm:
> consolidate empty_zero_page") this page was referenced in C code as an
> array and after that commit it is referenced as a pointer.
> 
> This causes wrong code generation and boot hang.
> 
> Declare boot_params_page as an array to fix the issue.
> 
> Reported-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> Tested-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> Fixes: 6215d9f4470f ("arch, mm: consolidate empty_zero_page")
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
>  arch/sh/include/asm/setup.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/sh/include/asm/setup.h b/arch/sh/include/asm/setup.h
> index 63c9efc06348..8488f76b48b4 100644
> --- a/arch/sh/include/asm/setup.h
> +++ b/arch/sh/include/asm/setup.h
> @@ -7,7 +7,7 @@
>  /*
>   * This is set up by the setup-routine at boot-time
>   */
> -extern unsigned char *boot_params_page;
> +extern unsigned char boot_params_page[];
>  #define PARAM boot_params_page
>  
>  #define MOUNT_ROOT_RDONLY (*(unsigned long *) (PARAM+0x000))
> 
> base-commit: 43cfbdda5af60ffc6272a7b8c5c37d1d0a181ca9

I can't test the patch myself now as my custom J2 toolchain is choking on building
the latest kernel from git. But the change looks good to me, so I'm going to merge
it now and send another PR to Linus.

Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

Adrian

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