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. -- Catalin
