On 3/16/20 10:26 AM, Catalin Marinas wrote: > On Mon, Mar 16, 2020 at 10:22:15AM +0000, Mark Rutland wrote: >> On Mon, Mar 16, 2020 at 09:42:32AM +0000, Vincenzo Frascino wrote: >>> On 3/15/20 6:30 PM, Catalin Marinas wrote: >>>> 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. >>>> >>> >>> I tried to fine grain the headers as much as I could in order to avoid >>> unneeded/unwanted inclusions: >>> * TASK_SIZE_32 is used to verify ABI consistency on vdso32 (please refer to >>> arch/arm64/kernel/vdso32/vgettimeofday.c). >>> * TASK_SIZE is not required by the vdso library hence it is not present in >>> these headers. >> >> It would be worth noting the former point in the commit message, since >> it can be surprising. >> >> I also think it's worth keeping the definitions together if that's easy, >> as it makes it easier to navigate the codebase, even if TASK_SIZE isn't >> necessary for the VDSO itself. > > It won't work as TASK_SIZE requires (on arm64) test_thread_flag() which > can't be made available to the vDSO. > Ups, I did not see this :) luckily I agree ;) -- Regards, Vincenzo
