[PATCH 1/7] arm64: mm: cleanup __do_page_fault()

[Suren Baghdasaryan]

On Tue, Apr 2, 2024 at 12:53 AM Kefeng Wang <wangkefeng.wang at huawei.com> wrote:
>
> The __do_page_fault() only check vma->flags and call handle_mm_fault(),
> and only called by do_page_fault(), let's squash it into do_page_fault()
> to cleanup code.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>

Reviewed-by: Suren Baghdasaryan <surenb at google.com>

> ---
>  arch/arm64/mm/fault.c | 27 +++++++--------------------
>  1 file changed, 7 insertions(+), 20 deletions(-)
>
> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> index 8251e2fea9c7..9bb9f395351a 100644
> --- a/arch/arm64/mm/fault.c
> +++ b/arch/arm64/mm/fault.c
> @@ -486,25 +486,6 @@ static void do_bad_area(unsigned long far, unsigned long esr,
>         }
>  }
>
> -#define VM_FAULT_BADMAP                ((__force vm_fault_t)0x010000)
> -#define VM_FAULT_BADACCESS     ((__force vm_fault_t)0x020000)
> -
> -static vm_fault_t __do_page_fault(struct mm_struct *mm,
> -                                 struct vm_area_struct *vma, unsigned long addr,
> -                                 unsigned int mm_flags, unsigned long vm_flags,
> -                                 struct pt_regs *regs)
> -{
> -       /*
> -        * Ok, we have a good vm_area for this memory access, so we can handle
> -        * it.
> -        * Check that the permissions on the VMA allow for the fault which
> -        * occurred.
> -        */
> -       if (!(vma->vm_flags & vm_flags))
> -               return VM_FAULT_BADACCESS;
> -       return handle_mm_fault(vma, addr, mm_flags, regs);
> -}
> -
>  static bool is_el0_instruction_abort(unsigned long esr)
>  {
>         return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
> @@ -519,6 +500,9 @@ static bool is_write_abort(unsigned long esr)
>         return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
>  }
>
> +#define VM_FAULT_BADMAP                ((__force vm_fault_t)0x010000)
> +#define VM_FAULT_BADACCESS     ((__force vm_fault_t)0x020000)
> +
>  static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
>                                    struct pt_regs *regs)
>  {
> @@ -617,7 +601,10 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
>                 goto done;
>         }
>
> -       fault = __do_page_fault(mm, vma, addr, mm_flags, vm_flags, regs);
> +       if (!(vma->vm_flags & vm_flags))
> +               fault = VM_FAULT_BADACCESS;
> +       else
> +               fault = handle_mm_fault(vma, addr, mm_flags, regs);
>
>         /* Quick path to respond to signals */
>         if (fault_signal_pending(fault, regs)) {
> --
> 2.27.0
>