Re: [PATCH v3 22/23] powerpc/vdso: Migrate native signals to generic vdso_base

[Christophe Leroy]

Le 11/06/2021 à 20:02, Dmitry Safonov a écrit :
> Generic way to track the land vma area.
> Stat speaks for itself.
>
> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
> ---

> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
> index 4bc45d3ed8b0..71dedeac7fdb 100644
> --- a/arch/powerpc/include/asm/mmu_context.h
> +++ b/arch/powerpc/include/asm/mmu_context.h
> @@ -260,15 +260,6 @@ static inline void enter_lazy_tlb(struct mm_struct *mm,
>   
>   extern void arch_exit_mmap(struct mm_struct *mm);
>   
> -static inline void arch_unmap(struct mm_struct *mm,
> -			      unsigned long start, unsigned long end)
> -{
> -	unsigned long vdso_base = (unsigned long)mm->context.vdso;
> -
> -	if (start <= vdso_base && vdso_base < end)
> -		mm->context.vdso = NULL;
> -}
> -
>   #ifdef CONFIG_PPC_MEM_KEYS
>   bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write,
>   			       bool execute, bool foreign);

powerpc was the only user of arch_unmap().

We should get rid of it completely (Remove the stubs in arch/x86/include/asm/mmu_context.h and 
include/asm-generic/mm_hooks.h and remove call in mm/mmap.c)