Re: [PATCH v3 18/26] arm64: Introduce asm/vdso/processor.h

From: Catalin Marinas
Date: Sun Mar 15 2020 - 14:30:17 EST


On Fri, Mar 13, 2020 at 03:43:37PM +0000, Vincenzo Frascino wrote:
> --- /dev/null
> +++ b/arch/arm64/include/asm/vdso/processor.h
> @@ -0,0 +1,31 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2020 ARM Ltd.
> + */
> +#ifndef __ASM_VDSO_PROCESSOR_H
> +#define __ASM_VDSO_PROCESSOR_H
> +
> +#ifndef __ASSEMBLY__
> +
> +#include <asm/page-def.h>
> +
> +#ifdef CONFIG_COMPAT
> +#if defined(CONFIG_ARM64_64K_PAGES) && defined(CONFIG_KUSER_HELPERS)
> +/*
> + * With CONFIG_ARM64_64K_PAGES enabled, the last page is occupied
> + * by the compat vectors page.
> + */
> +#define TASK_SIZE_32 UL(0x100000000)
> +#else
> +#define TASK_SIZE_32 (UL(0x100000000) - PAGE_SIZE)
> +#endif /* CONFIG_ARM64_64K_PAGES */
> +#endif /* CONFIG_COMPAT */

Just curious, what's TASK_SIZE_32 used for in the vDSO code? You don't
seem to move TASK_SIZE.

--
Catalin